Cloud cools

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Guest post by Erl Happ

This post was generated in response to the Christopher Monkton thread. It is not a criticism of Christopher Monkton but of our tendency to imagine that artful mathematicians (I am not one) are sufficiently sophisticated to deal with complex problems.  Indeed the debate as to the value of feedback processes illustrates the lack of utility of mathematics when unconstrained by observation of the real world. Climate Science is full of it.

As I understand it the proposition  goes like this:

Enhanced GG composition, more back radiation, enhanced evaporation, more cloud and IF cloud enhances back radiation, the surface warms. The enhancement of cloud density depending upon the IF supposedly represents the feedback.

But cloud reflects incoming energy. The feedback notion requires that the loss of energy to the surface due to cloud reflection of incoming short wave radiation is outweighed by the increase in energy trapped in the ‘below cloud level system’ due to cloud returning OLR to the surface. That’s the IF factor again.

The IF proviso requires that evaporation from the surface not only keeps pace with the increase in surface temperature. It must exceed it for cloud density to be enhanced as the surface warms.

There is a little logical problem here. If the feedback from long wave radiation exceeded the value of the reflected short wave, the oceans would soon boil. That problem is sidestepped by suggesting that it is only the high ice cloud that is important in the feedback. So, in the end the result depends upon the mix in the categories of clouds that provide net reflection versus those that provide net surface warming and whether the moisture supply to the atmosphere keeps up and somehow tips the balance towards those clouds that are supposed  to provide a net warming effect .

This is already too complex and includes  unknowns that are unquantifiable.

Now, lets look at the real world. Consider:

A

Do clouds warm the surface? Logically, if clouds had that effect, with more clouds the surface should warm. But near surface clouds arrive in warm tropical air. It’s warm because of its origin. The warmer and wetter it is the more the precipitation. This warm moist tropical air produces cloud and precipitation strictly in proportion to the chilling it receives. Warm that same air and the cloud disappears. (The Foehn effect). Precipitation enhances the supply of moisture at the surface cooling the surface. The air is in constant movement and the system is mind bogglingly dynamic. But one constant is the decline of surface temperature as we move from equator to pole. Satellites show that warm moist tropical air travels all the way but is dried as it moves. Hence the polar latitudes are cold deserts with the air in these regions containing little moisture that remains to be precipitated producing a gradually accumulating mass of ice in perennially sub freezing temperatures. Lesson: The presence of low clouds reflect very recent change in air temperature and is unrelated to the supply of moisture to the atmosphere from the surface. The presence of these clouds depends upon the supply of energy to the tropical ocean and the direction of the wind.

B

In mid latitudes the atmosphere between 600hpa and 100hpa (where the ice cloud called cirrus and stratus is located) responds in terms of its cloud cover to a moisture supply from places remote to the point of observation. (tropical convection, polar frontal action). Supply is relatively invariable and as a result cloud comes and goes according to flux in the temperature of the upper troposphere. Temperature in this zone is a function of ozone content and depends upon stratospheric processes. In the mid latitudes the troposphere above 300hPa contains appreciable ozone and peaks in temperature in mid winter when outgoing radiation peaks. At this time the surface reaches its seasonal minimum temperature. Radiation peaks in winter due to the enhancement of the high pressure cells of descending warming air  in the winter hemisphere. The temperature of the cloud bearing layer does not relate at all to change in surface temperature. If radiation increases the presence of ozone ensures that the air warms and the cloud disappears.

C

For cloud to increase as the atmosphere warms it requires that evaporation is enhanced as the surface warms so as to enhance relative humidity promoting enhanced cloud cover. This proposition is tested once a year in the northern hemisphere. Because of the preponderance of land which is opaque to short wave radiation (unlike the sea) near surface air temperature increases strongly. In effect the surface returns warmth to the atmosphere by conduction and radiation. The convective process of heat loss via decompression (that we see in the tropics) is inoperable because of an insufficiency of moisture supply to the atmosphere. Transfer by conduction and radiation is therefore enhanced and the entire troposphere  warms.

We see here that vvaporation fails to promote the addition of sufficient moisture to the atmosphere to maintain cloud cover. So, cloud falls away and global air temperature peaks in July in conformity with this strong seasonal influence driven by the accident of geography which is the northern hemisphere. A potential runaway feedback system that is the exact opposite of that posited above (warming surface more cloud) is curtailed by the passage of the Earth around the sun while it spins on its tilted axis.

In January, when the suns irradiance is 7% stronger due to orbital considerations global near surface air temperature reaches its minimum because global cloud cover peaks. Taken in its entirety, cool the Earth’s atmosphere and cloud increases. The surface cools. It will cool in the face of enhanced radiation.

Summarizing: Does the presence of cloud result in surface warming? No. In January, global cloud cover is 3% greater than July. Irradiance 7% greater. Surface temperature 4° cooler. Will a warmer sun heat the Earth? Not necessarily. It depends upon what happens to the cloud. If there were less land and more sea the ocean would gradually warm.

D

The proposition that cloud is enhanced as the near surface atmosphere warms is also testable by looking at historical data for precipitable water as the globe has warmed. Reanalysis tells us that it actually falls away.

E

The Earth system also demonstrates what happens when additional greenhouse gas is added to the troposphere. This happens in the coupled circulation over Antarctica. The system waxes and wanes according to the activity of the night jet in modulating the ozone content and temperature of the upper stratosphere. The convection that results involves warmer ozone rich air (10ppm) ascending. Relatively ozone poor stratospheric air (say 7ppm) descends into the troposphere (naturally containing ozone at the ppb level) that in consequence becomes ozone rich. The consequence is gross warming of the troposphere on the margins of Antarctica and the generation of the lowest surface atmospheric pressures on the planet. The flux in pressure in this zone depends simply upon the rate of ozone churn into the troposphere. Ozone is carried towards the equator by the counter westerlies destroying cloud as it moves by virtue of its greenhouse gas property. It absorbs at 9.6 micrometers.

As this greenhouse gas is added to the troposphere cloud cover falls away. The surface temperature feedback is due to enhanced shortwave radiation, not longwave retention. This too is a potentially disastrous feedback scenario that is limited by the fact that the ozone content of the stratosphere varies within limits and the Earth’s surface is mainly water which soaks up energy without adding a lot of moisture to the atmsophere. Given enough time, the feed rate of ozone peaks and shortly after atmospheric moisture and cloud cover recovers.

F

The prime source of long wave radiation emanating from the Earth system is the high pressure cells of the winter hemisphere where the air warms by compression as it descends, a cloud free zone promoting surface warming when it is most needed…………..despite the abundant long wave radiation streaming out to space.

Conclusion : Cloud cools.

113 thoughts on “Cloud cools

  1. And I forgot G the most important one.

    The Earth could do with being a couple of degrees warmer to better approach the optimum temperature for photosynthesis, and in particular in the southern hemisphere.

  2. Very concise description of the cloud system. What amazes me is the amount of mental effort being expended to characterize a naturally chaotic system…as seen by two extremely polarized points of view: one trying to emphasize the natural, the other trying to ramrod an alarming view of what is essentially a minute temperature variation. It is good to know these minutae for precisely the reason that there is a fight over their significance. But that fight is distracting great minds from solving real problems and issues, and that is very sad indeed. But nonetheless, the good fight must continue. May reason prevail.

  3. From a different point of view:

    1. Clouds happen in the troposphere (well, apart from some special kinds of clouds)
    2. Clouds reflect radiation back to space
    3. Radiative (“feedback”) effects are negligible in the troposphere (read raypierre’s book if you don’t believe that)

    Hence radiative effects have little or no roles to play wrt clouds, apart from reflection back to space.

    Therefore clouds can only cool. Empirically this can be shown in days when the sky is overcast apart from where the sun is. Were clouds to warm the surface, an “oven” effect would soon establish itself. Of course it never happens with any kind of tropospheric cloud: if it did it would violate the finding that radiative effects are negligible in the troposphere.

    Therefore clouds can only cool.

  4. Good piece.

    Two questions:
    1) Are you saying that the land mass is just the perfect size to keep a stabilized climate? This is an interesting point all by itself if that is what you mean.

    2) Long wave radiation from the land to clouds is energy lost by the land so the land must cool in proportion to it’s loss. Any reflection from CO2 in the atmosphere reaching the land again can at best be equal to what was originally radiated by it but it is probably a very small fraction therefore it is not remotely possible for it to heat anything, only to slow the cooling just a bit. If the same is true of the sea (as I assume) then how could anything but the absence of clouds cause the sea to boil?

  5. That 4C difference between summer and winter “global temperature” is also given by a fact, that the surface temperature above land varies much more than the SST. More land in northern hemisphere makes “global temperature” colder in winter and warmer in the summer.

  6. Erl Happ also forgets that better photosynthesis provides more sugar which makes more alcoholic wines which to my taste are more flavorsome. (Especially in Burgundy).

  7. Erl Happ:
    “I am a winemaker and grape-grower…….in our part of the world, the south west of Western Australia..”
    That would be the Margaret River, then, would it? Absolutely superb wines, but not common here in the UK.
    Nice, easy to follow article, by the way. Congratulations.

  8. In the mid latitudes the troposphere above 300hPa contains appreciable ozone and peaks in temperature in mid winter when outgoing radiation peaks.

    Outgoing radiation from the surface reaches a minimum in mid-winter.

    In January, global cloud cover is 3% greater than July. Irradiance 7% greater. Surface temperature 4° cooler. Will a warmer sun heat the Earth? Not necessarily.

    The higher solar irradiance in January does warm the oceans (and the climate) but not the atmosphere due to the larger land area in the NH losing heat faster than the oceans release it in January.

    Otherwise, whether clouds cause heat gain or loss will be determined by the amount of incoming solar radiation versus OLR and that will vary by lattitude, season and time of day.

  9. I played golf today in Brisbane, Australia. The weather forecast in our local ‘rag’ expected temperature of 27C. Well, it was a wonderful day, light breeze, played some good golf, and the sun stayed behind a layer low-mid level grey cloud … I’m sure that the temperature didn’t get above 24C at any time. I conclude that the clouds kept the day cool. Whilst on the subject of temperatures, I have noticed that our local weather forecast is habitually forecasting daytime temperature 2-3C above what is recorded the following day … I wonder?

  10. Nice article, well written and intelligible.
    You didn’t have to add the biographical details?
    It just seems like an invitation to ad hom attacks and thus a distraction from your article itself….which should stand or fall on its own merits.

  11. Back radiation is ultimately derived from solar energy that previously reached the surface and/or entered the oceans.

    If more incoming solar energy gets reflected before reaching the surface then it isn’t available to provide the fuel for the back radiation. If cloudiness increases then back radiation must decline too. There will be a delay due to the thermal inertia of the oceans but reflected energy is energy lost forever.

  12. Sorry, but you should define all abbreviations the first time used. I’ve read WUWT for years but GG and hpa escape me.

  13. Stone Age Climatology. Guess you guys are really arriving.

    Next chapter: the finding of a relation between cloud and precipitation? But first: the sun!

  14. If the feedback from long wave radiation exceeded the value of the reflected short wave, the oceans would soon boil.

    If the feedback factor is less than 1 then the oceans will not boil. For example, if the feedback is 0.5 then each unit has a feedback of 0.5 which itself has a feedback of 0.25 which itself has a feedback of 0.125 etc. The result is that the increase is 0.5+0.25+0.125+0.0625+… = 1
    A feedback factor bounded by -1 < feedback < 1 will not result in the oceans boiling or freezing.

  15. If clouds only cool, why are cloudy nights warmer than clear nights? Maybe it’s not QUITE as simple after all? Much like the long debated issue of whether contrails cause warming or cooling – they do both but the warming seems (on current evidence) to be slightly the greater. Clearly clouds at lower levels also both warm and cool.

  16. erl happ says:
    September 28, 2011 at 12:12 am

    And I forgot G the most important one.

    The Earth could do with being a couple of degrees warmer to better approach the optimum temperature for photosynthesis, and in particular in the southern hemisphere.

    Erl, thank you for a very informative article. Your “G” comment got me thinking. I’ve always been curious about what is the optimum temperature for life on earth? As I understand, photosynthesis reaches peak efficiency at around 25°C (77°F) then starts tapering off at around 35°C (95°F). The optimum temperature for most efficient metabolic function in cold blooded animals centers around 33°C (91.5°F) with heat stress occurring above 40°C (104°F). Warm blooded animals function well in a relatively broad range of temperatures so I’m thinking that plants and cold blooded animals tell most of the story.

    Based on the above, I’m figuring that a tropical zone temperature range of between 30°C (86°F) and 35°C (95°F) would be the optimum temperature range that most plants and animals evolved to thrive in. Not really giving it much thought in the past I always assumed human body temperature was optimum but it appears our thermostats run a little high if I’m figuring this right.

  17. @ Andy Mayhew:

    Cloudy nights are warmer than clear nights simply because clouds block most of the OLR. Some of it gets reflected back towards the earth. With no clouds, there is nothing to stop the OLR from radiating directly to space.

  18. Don’t forget that the ocean is not responsive to long wave infrared in the manner of land.

    Primary means of heating the ocean is sunlight which penetrates to great depth. Primary means of cooling the ocean is evaporation. Long wave infrared plays little role over the ocean as water is opaque to it. It neither radiates nor absorbs much LWIR due to the physical properties of liquid water.

    Failure to acknowledge the physical properties of liquid water in regard to radiative absorption and emission characteristics will lead to hopeless misunderstanding of the entire climate system.

    So long as the earth is a water world it is the water cycle which governs the climate response. Write that down.

  19. Minor but important point.

    “In January, when the suns irradiance is 7% stronger due to orbital considerations”

    Solar Irradiance doesn’t change, solar insolation changes.

  20. Great article as always Mr. Happ. And to DCC, GG = greenhouse gas and Hpa = hectopascals the standard measurement of atmospheric pressure.

  21. Andy Mayhew says:
    September 28, 2011 at 3:27 am
    #######
    My understanding is that high altitude clouds provide a net warming whereas low altitude clouds provide a net cooling. Then theres all the evaporation and convection thermal mechanisms involved in cloud formation and dissipation that are major transporters of heat. So you’re right, it isn’t so simple but my take away understanding of Erl’s article is that taking all into consideration, clouds cool.

  22. Andy the answer is simple- take ideal cooling conditions low dewpoint temperatures and combine that with clear skies end result cool temperatures- now at the same take clouds over that same area higher dewpoint temperatures only add clouds the clouds act as a blanket and doesn’t allow for ideal cooling conditions threw the night you may cool 2-3 degrees from the night before

  23. DCC says: “GG and hpa escape me”
    GG = greenhouse gas
    hpa (more properly, hPa) = hectoPascal, a measure of pressure. Atmospheric pressure at sea level is in the neighborhood of 1000 hPa, and the pressure decreases with altitude. E.g. 600 hPa corresponds to around 4 km above sea level. This is not an exact equivalence, as it varies with temperature and humidity (at least).

  24. Andy Mayhew says: September 28, 2011 at 3:27 am
    If clouds only cool, why are cloudy nights warmer than clear nights?

    Hot off the press: Allen 2011

    Clouds have a big cooling effect during the day, roughly 17 times that of a doubling of CO2. Unfortunately the paper is behind a paywall, so I can’t say how big the night warming effect is by comparison. But it looks by inference from the abstract that it is smaller.

  25. One effect of H2O you didn’t touch on is that gaseous water is itself a greenhouse gas; in fact, far and away the most important one. As I understand it, the models all use this fact to make up the gap between the theoretical greenhouse effect of enhanced CO2 and observed temperature (more positive feedback).

    However, when the water vapor re-condenses into clouds, that heat of vaporization is re-released higher in the atmosphere, bypassing the greenhouse gasses below (negative feedback). So you have another pair of competing processes: enhanced greenhouse effect due to the increase in absolute humidity of in warmer air, and heat energy being transported through a large layer of greenhouse-gas-laden air to be released higher up, thus bypassing some of the potential greenhouse effect altogether.

    The papers describing the climate models constantly use the phrase “well-mixed greenhouse gas”, but water vapor is certainly NOT well-mixed. Yet, it seems they treat it as “well-mixed” to produce the postulated greenhouse effect.

    My brain is starting to hurt.

  26. Carl Bussjaeger says:
    September 28, 2011 at 12:08 am

    “With one minor modification, I’d say that nails it: [Consensus] Climate Science is full of it.”
    _______________________________
    Nailed it.

  27. In other words, weather and address trumps climate change, and meteorologists trump climatologists. That must really bite. And to be sure, I really cleaned up my little pithy post.

  28. Andy Mayhew says:
    September 28, 2011 at 3:27 am

    If clouds only cool, why are cloudy nights warmer than clear nights?

    How about let’s turn that around. If clouds mostly warm, why are cloudy days cooler than clear days?

    Maybe it’s not QUITE as simple after all?

    I think you’ve missed the point of the article–that the relationship is not simple at all. Certainly not as simple as the climate models assume. And therefore, they are necessarily wrong.

  29. Thank you Earl for this so obvious and straight forward post.
    One only have to look at the atmosphere to realize what you wrote here.
    I think the bottom lines should be this:
    Clouds cool by reflecting incoming radiation.
    Clouds DELAY cooling by absorbing outgoing long wave radiation.
    It is as simple as that.

  30. I don’t understand this, Erl, but my intuition tells me you are on the right track. The system is too complex even for supercomputers, but I’m not sure it’s beyond the grasp of the human mind. You seem to be closer to holistic understanding than any other. I wish you and Robert Ellison and Stephen Wilde and Bob Tisdale and a few others would collaborate.
    ====================

  31. “If the feedback from long wave radiation exceeded the value of the reflected short wave, the oceans would soon boil.”

    Whether positive or negative, clouds are not the only feedback. There are many others, including a well understood powerful negative feedback, black body radiation. Radiated heat is proportional to the fourth power of absolute temperature.

  32. WOW.

    Mr. Happ, I don’t know you, but I deeply appreciate that you can explain something so complicated in a way that even I can understand it. Thank you.

    I would just like to posit a question (to anyone willing to answer), because of something I know which runs counter to this, and it is fairly common knowledge.

    Upper Midwest-latitude, Winter night; if it’s crystal clear, it is guaranteed to be cold. Very cold. If it is cloudy, it is most certainly 20 – 30 degrees warmer. The consensus is that this is because the clouds act as a blanket, trapping the Earth’s heat nearer to the ground, whereas the lack of clouds allows that heat to escape.

    My understanding of the article is that this has more to do with the origin of the air which happens to have clouds in it than any ‘blanket’ effect. (i.e. a clear sky means a high pressure front from Canada, whereas cloudy means low pressure from the gulf)

    Is my understanding correct?

    Thanks for anyone who responds.

  33. I’m dazzled at the comprehensiveness of this presentation. I was particularly please to see a rational explanation for why the annual rise and fall of global average temperature at the higher altitudes is approximately 180 degrees out of phase with those at the earth’s surface. It was much more satisfying than simply hearing “the preponderance of land mass resides in the northern hemisphere”.

  34. @Andymayhew: “If clouds only cool, why are cloudy nights warmer than clear nights? Maybe it’s not QUITE as simple after all? ”
    Befuddled by the description of the cloud forming mechanism, the reader misses the entire point..

    Dear Andy.. Start with the concept ALL Surface energy is inevitably lost to space. Energy lost to space never comes back.
    Cloud reflected energy never makes it to surface in the first place thus cloudy day is cooler, night is warmer due to reradiation, not reflection. AIr still cools as night goes on, doesn’t it; if morning never comes {sun doesnt rise}, cooling continues as reradiation is in all directions, mostly toward space because earth is a ball.

    Contrails are nothing but clouds.. same thing applies, they reflect/reradiate solar, reradiate surface radiation. MOSTLY TOWARD SPACE! Why even bother to bring them up other than to protect your world view?

  35. RR Kampen says:
    September 28, 2011 at 2:51 am

    RR, I hope you are being facetious.

    This IS the state of climate science. The net effect of clouds is very much in debate, and as we are studying a chaotic system it is likely that different clouds produce different effects given different atmospheric conditions.

    If you are somehow thinking modern climate science has advanced much beyond this, I would direct you to CERN’s recent CLOUD experiment where they attempt to learn about what causes (influences) cloud formation. Yes, we have that much to learn.

    In short, there is so much we really don’t know or fully understand that anyone caught claiming the science is settled should be asked to shut up so real scientists can get on with discovering what really goes on in our atmosphere. If your post is intended denigrate the discussion here, you are likely incapable of understanding the issues of climate science in the first place.

    If I misunderstood the nature of your post, then I apologize in advance for the terse nature of my response.

  36. I haven’t read your piece yet Erl, but could you please at least spell Lord Monckton’s name correctly.

  37. “”””” F

    The prime source of long wave radiation emanating from the Earth system is the high pressure cells of the winter hemisphere where the air warms by compression as it descends, a cloud free zone promoting surface warming when it is most needed…………..despite the abundant long wave radiation streaming out to space.

    Conclusion : Cloud cools. “””””

    Well I agree with your conclusion, I’ve been making that statement for some years now, to little or no avail.

    But I would suggest that the hot dry deserts of the middle East and north Africa are the source of a lot more LWIR and it is shorter wavelength than the cool zones, so it escapes CO2 easier. Remembert hat T^4 effect, and Wien’s law.

  38. Increased cloud cover on balance causes cooling. At least low cloud in the tropics during the day cause cooling.
    But as mentioned cloud cover is NOT directly corellated with temperature or humidity, the interactions are a little more complex and dynamic than that…

    On the other hand increased temperatures DO increase water vapor/humidity levels as direct observation confirms, so warming from any cause gets a positive feedback from increased water vapor.

    Only if that increase in water vapor causing wearming ALSO increases low cloud coverage during daylight in the tropical region will the cooling from cloud cover negate the warming from water vapor increases.

  39. “”””” Andy Mayhew says:

    September 28, 2011 at 3:27 am

    If clouds only cool, why are cloudy nights warmer than clear nights? “””””
    th that results in the clouds; NOT the other way round.
    You got it wrong Andy. Warmer nights are more cloudy than colder nights. It’s the surface warmth that results in the clouds; NOT the other way round.

  40. Any paper that suggests cloud feedback is negative will not be allowed to stand. Any such paper is held up by publishers until the Team has a rebuttal written. The only slip up recently was SB11 at RS, and the publisher resigned and publicly apologized to Trenberth.

    It seems quite evident that The IPCC conclusion has already been written by Trenberth and the IPCC. Cloud feedback is positive and any scientific paper that says otherwise will by suppressed by the Team. This strategy was publicly laid out in the Climategate emails.

    This isn’t about science, it is about religion and money. The Team believes that fossil fuels are bad. The way to end the use of fossil fuels is to tax them out of existence, using fear as the motivator. Funding the Team are the greedy individuals that intend to get their hands on the tax money. How to get filthy rich 101 – tax the poor in the name of saving the world.

    Climate Science is the religion. Carbon taxes are the collection plate. Global warming is the fire and brimstone of Hell. Al Gore is the savior. We are the sinners than need to be punished.

  41. kim says:
    September 28, 2011 at 6:19 am
    “….. I wish you and Robert Ellison and Stephen Wilde and Bob Tisdale and a few others would collaborate.”

    That is sort of what they are doing here at WUWT, but I understand what you mean. Take all the bits and pieces and meld them into a whole. And do not forget Willis’ Thermostat theory.

    I noticed that as you move along the east coast of the USA the number of afternoon thunderstorms per month during the summer decreases as you move north. They pretty much “stop” when you hit mid North Carolina and the prevalence of very hot (>90F) afternoons become less. – just another bit of support for the Thermostat theory.

  42. Thanks for the comments. This is a complex topic and I must admit I had no immediate inclination to get involved.

    BargHumer says: September 28, 2011 at 12:50 am
    1) Are you saying that the land mass is just the perfect size to keep a stabilized climate? This is an interesting point all by itself if that is what you mean.

    My main point is that geography and the geometry of the seasons matters. When the atmosphere cools more cloud appears and the surface cools, precipitation falls further cooling the surface, cooling the air which forms more cloud………..but there are natural limits to the extent of feedback processes because of orbital and tilt considerations. And those natural limits work to prevent excessive warming or excessive cooling even in situations where the feedbacks are strongly positive. But the evidence is that cloud per-se is a cooling influence in that it reflects short wave radiation. When you think of it, night and day represent different systems like summer and winter.

    The system is never static, it moves from phase to phase and the parameters vary accordingly. I don’t think the mathematical equations represent the real world properly when its basic nature is changing continuously.

    how could anything but the absence of clouds cause the sea to boil?

    If the hypothesized radiation trapping property of cloud were to be more influential than its short wave reflective property the energy in the below cloud environment must increase continuously. Winter would be warmer than summer.

    Philip Bradley says: September 28, 2011 at 1:58 am
    Outgoing radiation from the surface reaches a minimum in mid-winter.

    For sure. But the radiation from the mid latitude atmosphere (as distinct from the surface) peaks in winter because the high pressure cells of descending air warm by compression and they are always stronger in the winter hemisphere. That radiation peak delivers a winter maximum in the temperature of the stratosphere and the upper troposphere. There is sufficient ozone in the upper third of the troposphere to make it behave like the stratosphere and warm when radiation increases.

    whether clouds cause heat gain or loss will be determined by the amount of incoming solar radiation versus OLR and that will vary by lattitude, season and time of day.

    Excellent point. And perhaps we should map the way the balance changes by latitude and time of year and we could resolve this question.

    Darkinbad the Brightdayler says: September 28, 2011 at 2:12 am
    You didn’t have to add the biographical details?
    That’s Anthony introducing his guest author and pointing out that there have been other articles.

    Stephen Wilde says: September 28, 2011 at 2:17 am

    reflected energy is energy lost forever
    Look s like excellent reasoning.

    DCC says: September 28, 2011 at 2:42 am
    GG- greenhouse gas. hPa =hectopascals a measure of atmospheric pressure equivalent to millibars.

    TerryS says: September 28, 2011 at 2:54 am
    If cirrus (or water vapour if you like) did not reflect short wave energy at all but effectively raised surface temperature due to its supposed ability to mimic the warming role of the sun, and if the warming at the surface promoted an increase in cirrus (or water vapour) we have a double feedback. And if we were dealing with a constant level of solar radiation over time, no day and night and no seasons then how does that play out?

    In the real world the increase in the water vapour content of the atmosphere would result in convection and therefore decompressive cooling rather than radiative cooling and as radiation fell away at this place it would increase in another place. Then in that other place due to the fact that the air warms by compression as it descends there would be no cloud at all. Those cells of descending air would form in cool places like the winter hemisphere where the extra warmth from greater sunlight would be appreciated. Meanwhile back at the ranch, there is less radiation and the modeled feedbacks would be all awry. The ranch would not have warmed in the manner expected.

    The equations need to be solved for latitude, the nature of the surface, day and night, the seasons and the influences from the stratosphere that determine high altitude cloud cover. The relationship between energy incident at the surface and the agent causing the surface to become warmer must be quantified. Can it be done?

    Andy Mayhew says: September 28, 2011 at 3:27 am
    why are cloudy nights warmer than clear nights?

    Because the air containing cloud is warm having come from a warm place.Its a gloriously diverse world that we live in and the air is in constant movement. Ah, the scent of frangipannis from the tropics. Bit of cloud about? Air is warm isn’t it. Humidity is up too.

  43. @Bob Kutz. I don’t think that the blanketing effect of clouds have anything at all to with where they were formed although how thick the cloud cover is does. It isn’t really much different from how real blankets work. A real blanket traps heat from escaping it doesn’t provide any heat (unless it is an electric blanket). Clouds work the same way, holding heat in, but not creating heat. But a blanket doesn’t hold all heat in, it just slows the rate at which heat escapes. That is the way clouds work, they slow the rate at which heat escapes to space, they don’t stop it 100%.
    During the day clouds slow the rate that incoming warm sun light reaches the earth . At night they slow the rate at which the warmed air below them escapes.

  44. Cloud cools. Period
    And the entire subject of enhanced GG back radiation where infra red warms the earth and generates more evaporation is total nonsense.

    No “if”s, just bad science.

    Nasif S. Nahle: Observations on “Backradiation” during Nighttime and Daytime

    Abstract

    Through a series of real time measurements of thermal radiation from the atmosphere and surface materials during nighttime and daytime, I demonstrate that warming backradiation emitted from Earth’s atmosphere back toward the earth’s surface and the idea that a cooler system can warm a warmer system are unphysical concepts.

    http://climaterealists.com/?id=8402

    I also ask your attention for this article about thermometers published at Climate Realists

    http://climaterealists.com/?id=8401

    I can’t judge if the claims made in the article are correct so I throw it to the WUWT wolves:

    “John O’Sullivan: Thermometer Manufacturer Destroys Greenhouse Gas Warming Myth
    Monday, September 26th 2011, 4:29 PM EDT Co2sceptic (Site Admin)
    An independent climate science think tank produces evidence from a leading infrared thermometer manufacturer proving that climatologists were mistakenly taking incorrect readings of atmospheric temperatures. Latest findings are set to trigger a paradigm shift in climate science”.

    Researchers from Canada, USA, Mexico and Britain this week announce a startling discovery that destroys 20 years’ of thinking among government climatologists.

    Climate scientists had long believed infrared thermometers measured thermal radiation from the atmosphere and assumed it was ‘proof’ of the greenhouse gas effect (GHE). Their assumption was that infrared thermometers (IRT’s) were measuring ‘back radiated’ heat from greenhouse gases (including water vapor and carbon dioxide). But damning new evidence proves IRT’s do no such thing.

    Now a world-leading manufacturer of these high-tech instruments, Mikron Instrument Company Inc., has confirmed that IRT’s are deliberately set to AVOID registering any feedback from greenhouse gases. Thus climate scientists were measuring everything but the energy emitted by carbon dioxide and water vapor.

    One of the researchers involved, Alan Siddons, has analyzed the GHE for over six years. He has long condemned the practice of using IRT’s as a means of substantiating the increasingly discredited hypothesis.”

  45. So lets look at this…
    “Enhanced GG composition, more back radiation, enhanced evaporation, more cloud and IF cloud enhances back radiation, the surface warms.”
    So, to begin with, enhanced GG composition, specifically CO2, check, there is more CO2.
    More back radiation, is there more now that there is more CO2? Lets look at that.
    Interstellar Bill says: (on this thread http://wattsupwiththat.com/2011/09/27/monckton-on-pulling-planck-out-of-a-hat/#more-48277 )
    September 27, 2011 at 8:47 pm

    I’ve done lots of of infrared sky-temp measurements,
    thirty-five years ago, and today, with the same pyrgeometers.
    Their unchanged readings contrast sharply
    with Alarmism’s computer-predicted increases.

    http://en.wikipedia.org/wiki/Pyrgeometer

    There is NOT more back radiation despite more CO2.
    STOP.
    Without that more back radiation, there is no enhanced evaporation, and no more clouds, which enhance it further.
    There is NOT more back radiation.
    Conclusion, the entire chain of reasoning here is irrelevant, the initial conditions have not been met to even START this chain of events.

    Lets put it in terms of formal logic.
    Let us call “enhanced GG composition” A.
    Let us call “more back radiation” B.
    Let us call “enhanced evaporation” C.
    And let us call ” more cloud and IF cloud enhances back radiation, the surface warms” D.
    The theory of global warming states:
    If A is true then B.
    If B is true then C.
    If C is true then D.
    A is true.
    B is NOT TRUE.
    Therefore neither are C or D.
    It all depends entirely on B, “more back radiation”, this can be measured with a Pyrgeometer, it has been, and there is not more back radiation.
    Conclusion, the entire logic of global warming is falsified due to false premise seen by direct observation.
    Note also that if B is not true, it is irelevent if clouds enhance background radiation, since if B is not true, we never get to D to begine with.

    What is needed is a worldwide measrement of background radiation at the surface over as long a time period as possible, which we have the instruments for and have had for a long time. We then make that into a graph, and overlay that with a graph of incrweasing CO2. If the CO2 goes up, which it has, yet the background radiation does not, we therefore see, once and for all, by direct measurement, that the entire idea of global warming has been scientifically falsified by a direct application of the scientific meathod.
    So lets get with it.
    This is a science site, right?

  46. izen says:
    September 28, 2011 at 6:54 am

    You have the theory right. You need to supplement it with some experience. Start with Eschenbach’s thunderstorm model. That model captures the very dramatic pattern that dominates central and south Florida during summer (May – September). The high is well above 90 daily and evaporation is huge. The thunderstorms, coming from both coasts, arrive in Orlando between 3 and 5 PM daily. The result is huge cooling. Temps drop from 95 to 85 and stay down. If the storms are carrying a lot of water the temps can drop 20 degrees.

    The overall effect is cooling that seems never to make it into Warmista factual records. Sure, the daily summer high in central Florida is 90 to 95 but it falls off a cliff about two hours later.

  47. Unless we are talking about THUNDERSTORMS, as a private pilot, I can tell you most cloud cover on “cloudy nights” is “stratus”…I.e., 6000 feet to 12,000 feet. THUS a LARGE FRACTION OF THE ATMOPSHERE is above them and has NO interruption in OLR during the night. SO we need to deal with “net” effect. Overall, since the clouds have reflected 50% of the incoming short wave (compare like 15% from land and sea), it doesn’t take .01% statistics and years of data to work out the balances and show they favor “cooling” versus warming.

  48. There’s a great paper/video that talks about how impossible it is to convince people about the facts of AGW if they are not well versed in science/math to begin with. About 10% of the population has sufficient science intellect to grasp the intracies of climate change. That means that we realists can preach all we want to the poorly educated all for naught.

    http://www.sms.cam.ac.uk/media/1083337

    The Yale study says that most people rely on first contact to get their impressions of the competency of a source. So if your neighbor tells you that Gore is the greatest climatologist since God, absent any immediate influence to the contrary, they buy it. In other words, trying to convince the 90% who are science illiterate may be futile.

    As much as I enjoy preaching to the choir, it’s the sinners in the parish I worry about.

  49. Erl Happ: Your post includes the following fatal flaw, primarily because you are considering only global surface temperatures and global cloud cover.

    You wrote, ”In January, when the suns irradiance is 7% stronger due to orbital considerations global near surface air temperature reaches its minimum because global cloud cover peaks. Taken in its entirety, cool the Earth’s atmosphere and cloud increases. The surface cools. It will cool in the face of enhanced radiation.”

    And that plus some preceding discussions brought you to the following conclusion, “Summarizing: Does the presence of cloud result in surface warming? No. In January, global cloud cover is 3% greater than July. Irradiance 7% greater. Surface temperature 4° cooler. Will a warmer sun heat the Earth? Not necessarily. It depends upon what happens to the cloud. If there were less land and more sea the ocean would gradually warm.”

    The reality:

    The seasonal variation in global surface temperature is dominated by the Northern Hemisphere:

    And that of course is dictated by the dominance of the variations in Northern Hemisphere Land Surface Temperatures:

    But, the seasonal variation in cloud amount is dominated by the Southern Hemisphere, which has much greater variability over the course of a year and a significantly higher cloud amount than the Northern Hemisphere. More ocean surface area yields more cloud cover maybe, Erl?:

    And if you were to compare the seasonal cycles per hemisphere, you’ll note that the hemispheric cloud amounts vary somewhat in synch with the hemispheric surface temperatures, more toward the SST data than LST data, indicating that on a hemispheric basis, when surface temperature rises and falls, cloud amount rises and falls.

  50. “…oceans would… boil…”

    You lost me right there. TerryS has it right – a positive feedback doesn’t necessarily/usually lead to a runaway effect. It just leads to a different equilibrium state. I would say the original post is a bad advert for optimism/skepticism on climate science. There are plenty of better/quantitative/empirical arguments.

  51. With all due respect, Erl you are not an engineer and have not quite grasped heat transfer occuring at surfaces but it seems you have a better idea than most of those you call themselves climate scientists. There are four types of heat transfer at surfaces 1/ conduction which occurs within solids and is described by Fourier’s law; conductivity is analogous to the reciprocal of resistance in an electrical circuit 2/ convection natural and forced occurs with fluids (liquids & gases); engineers have determined analogies between momentum transfer and heat transfer. 3/ phase change -mainly associated with a change of liquids to gas and vice versa but can include liquids to solid and solids to gas (eg clouds of CO2 crystals as on Venus) -clouds in earths atmosphere consist of droplets of water and particles of ice 4/ radiation. The alarmists seem to think radiation is the “only game in town” when in fact radiation in some wavelengths may not occur at all. CO2 only absorbs and radiates in very narrow wavelength range and only if there is difference. People in cold countries would be aware of chill factors due to forced convective heat loss by the wind. Convective heat transfer will occur within clouds between air and the surfaces water droplets and ice particles. Mass transfer usually accompanies heat transfer by convection and phase change. It seems that climate scientist confuse convection with mixing.
    Overall, as others have indicated the energy transfers in the atmosphere are very complex and certainly can not be modelled by linear equations.

  52. “Enhanced GG composition, more back radiation, enhanced evaporation, more cloud and IF cloud enhances back radiation, the surface warms. The enhancement of cloud density depending upon the IF supposedly represents the feedback.”

    I have a logical disconnect between the “enhanced evaporation” and “more cloud”. The greater back radiation will increase the surface temperature, leaving the dew point temperature the same. So the relative humidity drops. Evaporation enhances, yes, but the new relative humidity level will be slightly less than the original relative humidity level. The abundance of cloud, one presumes, is a function of the relative humidity. So this will tend to slightly lesser amounts of cloud, but slightly greater absolute humidity. The greater absolute humidity will tend to warm due to enhanced back radiation. The slightly lesser amounts of cloud will tend to reflect less sunlight, thus also tending to warm, creating overall positive feedback.

    Of course I am merely questioning the logic in the presentation rather than making any comments on the actuality of the physics in the atmosphere.

  53. Re: “… a positive feedback doesn’t necessarily/usually lead to a runaway effect. It just leads to a different equilibrium state.”

    Yes, consider the negative feedback example of a boss intending to give an employee a “take-home” bonus of $100:

    Boss: Here’s a $100 bonus, go enjoy a $100 meal with your wife.
    Empl: Thanks Boss, but my tax rate is 50% so that will only buy us a $50 meal.
    Boss: Oh sorry, here’s another $50 to make up the shortfall.
    Empl: Thanks again Boss, but now you’ve given me $150, so after taxes I only have $75
    Boss: Crap, here’s another $25.
    Empl: Still $12.50 short

    … and so on until they get to a $200 forcing resulting in a $100 equilibrium.

    Now if the tax rate was >= 100% (like here in Canada ;), an infinite number of dollars still wouldn’t result in a $100 equilibrium.

  54. HankH says: September 28, 2011 at 4:25 am
    Hank, you are coming across as a first principles thinker who likes to get to the basics. I like that. The most appropriate temperature has got to be the one that maximizes plant growth and as you point out its 25°C. For sustenance you can’t beat a warm winter and a hot summer with the opportunity for double cropping. It’s no accident that southern China and the Indian subcontinent have a high population density. They wear a shirt and shorts most of the year which is not a bad way to go. Much of the globe is miserably cold most of the time. We could definitively do with a bit more warmth. It’s good to get right down to the basics.

    Dave Springer says: September 28, 2011 at 4:32 am
    So long as the earth is a water world it is the water cycle which governs the climate response. Write that down.

    So long as the earth is a water world it is the water cycle which governs the climate response.
    Delicious.

    kim says: September 28, 2011 at 6:19 am
    Thanks for your confidence Kim. It’s about four years now since I started making a nuisance of myself at Climate Audit and I am a lot closer today, just a question of explaining it adequately. It’s always a delight to find a comment from Kim.

    Bob Kutz says: September 28, 2011 at 6:27 am
    Your explanation is precisely the way I am reading it Bob. Temperature is pretty well a function of wind direction.

    It’s often observed that deserts cool down rapidly at night. Better to live next to a big lake where the water stays warm than live in a place where the water in the kettle turns to ice overnight and the air is both bitingly cold and shockingly dry. It’s not the cloudless nature of the place. It’s the lack of a decent store of warmth that accounts for the freeze.
    If you measure the down-welling radiation on a cloudy night you are measuring down-welling radiation in warm moist air. Of course there is going to be more of it about.

    George E. Smith says: September 28, 2011 at 6:51 am
    But I would suggest that the hot dry deserts of the middle East and north Africa are the source of a lot more LWIR and it is shorter wavelength than the cool zones, so it escapes CO2 easier. Remembert hat T^4 effect, and Wien’s law.

    Great point. There is nowhere on the Earth that gives off more radiation directly from the surface. That great diurnal temperature range in the desert gives us an idea of the energy residence time. Oh for a greenhouse effect. Where is it when you really need it? OK I will settle for a wind off the sea. Day and night.

    izen says: September 28, 2011 at 6:54 am
    warming from any cause gets a positive feedback from increased water vapor
    Not in the northern hemisphere in summer.
    Not in the desert
    Not over cold ocean or ice
    Not as much in still air
    Less over the ocean than over rain forest
    And where does the water vapour appear? Is it at lower levels where the cloud is said to be reflective. Does it rise into the middle and upper troposphere to form ice cloud. Ice cloud has a much greater reflective area than water droplet cloud. At what point in terms of elevation does the back-radiation effect become ineffective in terms of raising surface temperature?

    tom T says: September 28, 2011 at 7:24 am
    Tom, here is another perspective:

    Viewed from space the troposphere is so thin as to be indistinguishable from the actual surface of the Earth. The Earth has a diameter of 12,756 km. If the Earth were a mattress with a thickness of 300mm and it were to be covered in a blanket in the proportion that the troposphere bears to the Earth itself, that blanket would be just 0.35 mm in thickness, the equivalent of about five sheets of newspaper. It is the nature of the troposphere that it is hopelessly unstable. Imagine sleeping in the nick under five sheets of newspaper with the lowest one removed every thirty seconds and placed on top. Occasionally someone comes with a watering can to make sure that you are not overheating. That is the sort of greenhouse we live in.

    Bob Tisdale says: September 28, 2011 at 8:15 am
    Thanks for your contribution Bob. I have a different understanding of the phenomenon.

    January: http://climatechange1.files.wordpress.com/2011/09/jan.jpg
    July: http://climatechange1.files.wordpress.com/2011/09/july.jpg

    It is evident that all the driest parts of the land have less cloud in July than they do in January. It is also plain that there is less cloud in July than in January.

    Paradoxically, there is more dark blue (less cloud) between the equator and 30° south in southern winter (July) than in summer. This follows from the fact that the great high pressure cells of the Hadley circulation favor the winter hemisphere. Massive low pressure cells form over land in the northern hemisphere as the land heats up. The air must come down somewhere and as it does so, that area will lose cloud due to compressive warming, the bike pump effect.

    In mid year the global atmosphere warms. As it does so cloud cover falls away but due to circulatory influences most of the loss is in the southern hemisphere.

    Cementafriend says: September 28, 2011 at 8:20 am
    as others have indicated the energy transfers in the atmosphere are very complex and certainly can not be modelled by linear equations.

    That is exactly the point that I set out to make.

    peter_ga says: September 28, 2011 at 8:27 am
    Your point is well made. I failed to elaborate on the changed humidity relations. And since changed absolute humidity per-se is postulated to be the source of amplification (as well as high altitude cirrus cloud) one needs to be sure that humidity actually increases as the CO2 content of the air increases. The evidence from reanalysis data shows that total precipitable water increases with sea surface temperature but the increase in atmospheric moisture failed to keep pace with SST in successive El Nino episodes between 1978 and 1998. So, relative to the temperature of the sea, precipitable water lagged and one would suggest, with it, cloud cover. However, over the last seven or eight years, as CO2 has continued to increase, precipitable moisture has staged a remarkable recovery.

    This should tell us that the relationship is not simple and that some other factor than Greenhouse Gas influence is probably responsible for the warming that has occurred. Certainly it appears that a decline in cloud cover was likely an important factor explaining the warming while an increase in cloud cover over recent years is consistent with a cessation of that warming.

    Anyway, no consistent link between CO2 and atmospheric water vapor content.

  55. Here’s an IF. IF clouds affect the climate by providing a change in the sensitivity of the climate, you could have a scenario where clouds actually regulate the Earth’s temperature and provide a throttle of sorts. Say that an increase in WM^2 causes an increase in cloudiness that decreases the sensitivity of the climate by increasing the thermal mass of the atmosphere. Say you go from (simplifying, of course) 2W/M^2 to 3. And this lowers the sensitivity from .75 to .5. You have 2*.75=1.5 and 3*.5=1.5.

  56. C. Summarizing: Does the presence of cloud result in surface warming? No. In January, global cloud cover is 3% greater than July. Irradiance 7% greater. Surface temperature 4° cooler. Will a warmer sun heat the Earth? Not necessarily. It depends upon what happens to the cloud. If there were less land and more sea the ocean would gradually warm.

    It is also very useful to consider the diurnal progression: overnight the surface and near surface cool; after sunrise, surface and near surface start to warm, and continue warming; the warming produces all the usual effects such as increased water vapor content, thermals, and eventually towering clouds; the clouds spread out, and the net effect of clouds is to reduce direct solar irradiance while increasing the feedback, a net cooling effect; in line with Willis Eschenbach’s hypothesis, the warmer the early daytime, the bigger the clouds and the bigger the net cooling effect of the clouds; late afternoon and evening produce rain, fog, or dew; then there is overnight cooling. Notice that through all of this, the discrepancy between actual temperatures and energy flows, and their equilibrium approximations is not very great.

    What happens if atmospheric CO2 doubles? AM warming is about the same, heat retention near surface (and down radiation) are increased, water vaporization is increased, cloud formation is increased, and the cooling effect of the clouds is increased. It is possible in this scenario that the effect of increased CO2 is to decrease pm temperatures near surface, by increasing the rate of transfer of heat from low troposphere to high troposphere. Again, the effect is small compared to the equilibrium distributions of water vapor and heat, but important for crops and other aspects of human civilization.

    I expect Willis Eschenbach’s work to stimulate work like his by others. Important evidence probably resides in the TAO data sets that he brought to our attention.

    This is not a disagreement with Erl Happ, merely an elaboration of other possibilities..

  57. I wrote: by increasing the rate of transfer of heat from low troposphere to high troposphere.

    I omitted the increased effect that the clouds would have have on reflecting the incoming light.

  58. Erl Happ says: “Thanks for your contribution Bob. I have a different understanding of the phenomenon.
    January: http://climatechange1.files.wordpress.com/2011/09/jan.jpg
    July: http://climatechange1.files.wordpress.com/2011/09/july.jpg

    I presented graphs with the souces of the data and the time span identified, and you reply with maps of a January and a July–or are they a collection of Januarys and Julys? Please plot the annual variations in the data per hemisphere as I had in my graphs and identify your source.

  59. “”””” izen says: September 28, 2011 at 6:54 am
    warming from any cause gets a positive feedback from increased water vapor
    Not in the northern hemisphere in summer. “””””

    Well izen is quite wrong; and it would be much easier for people to understand the issue, if they stood back and took a look and realized that IT IS THE SUN THAT DRIVES THE SYSTEM !!!

    70% of the earth surface is water; and in the tropics (+/- 23.5 deg Lat) more than 75% of the surface is deep oceans.
    Sunlight penetrates to around 700 metres, and deposits 97-8% of its energy in that water body.
    Earth’s Temperature ultimately depends on how much solar energy is stored in that ocean water. It eventually emerges into the atmosphere and other systems to create climate.

    WATER; H2O IN ANY FORM; SOLID/LIQUID/GAS ABSORBS A LOT OF SUNLIGHT Maybe 20% of the incoming solar spectrum at wavelengths from around 700 nm to 4.0 microns. 44% of the solar energy is in that range at the surface, and only 1% extends beyond 4 microns. Water may absorb as much as half of that 700 to 4,000 nm spectral range of energies. I’ll let you MODTRANS fans do that calculation.

    So every single additional molecule of H2O that makes it into the atmosphere, from evaporation or plane/car engine exhausts or airliner toilet dumps will capture more solar energy so it NEVER reaches the deep oceans.

    The solar energy that water vapor captures, DOES heat the atmosphere. As a result, the atmosphere radiates MORE LWIR radiation. That emission is ISOTROPIC so half of it goes upwards and escapes to space (eventually) and ONLY HALF comes down to the surface (downwelling radiation).

    So that is A NET LOSS OF ABOUT HALF of the incoming solar energy that was captured by water vapor.

    Moreover, the half that arrives at the surface as enhanced LWIR emissions from the atmosphere, DOES NOT get stored in the deep oceans; it is absorbed in the top 10-50 microns of the water surface, where it most likely results in prompt evaporation of MORE WATER VAPOR.

    Along with that extra water vapor,comes a lot of LATENT HEAT OF EVAPORATION that removes even more heat from the ocean system. There can be very little extra heat going into the deep ocean from surface absorption of down LWIR radiation; downward conduction is TRUMPED BY UPWARD CONVECTION.

    Oh I almost forgot; more water vapor (evaporation) means MORE CLOUDS; …SOMEWHERE !!!

    Yes the conditions that create evaporation may not lead to local clouds. Fear not, because ALL of that extra H2O MUST come back down as precipitation somewhere. Evap= precip, is one of the axioms of climatology. Where I come from it is traditional to have clouds accompany our precipitation; and more clouds (anywhere) means, and more sunlight reflected to spac means more albedo, and even more sunlight reflected back into space.

    Read Frank Wentz et al, SCIENCE, for July-7 2007. “How much more rain will global warming bring.” Answer is 7% more per one deg C rise in mean earth surface Temp. He measured it.

    And Bob Tisdale has mentioned that number on many occasions here at WUWT. Something to do with somne “Clausius Clapeyron equation”, so even the modellers agree with that 7% number.

    And one other factoid. Evaporation is a consequence of the Temperature of THE LIQUID; NOT THE ATMOSPHERE. So it is sunlight plus LWIR that causes evaporation. Yes the atmosphere Temperature and winds will affect the rate of evaporation. I’m NOT a chemist; but it relates to the fact that any bidirectional chemical reaction will come to a screeching halt if you do not remove the reaction products from the scene of the crime. So winds whisking the newly evaporated H2O molecules away from the surface is essential to rapid evaporation; but it is only the liquid surface Temperature that determines IF evaporation will occur.

    So please stop talking about these entirely peripheral minutiae, like where and how clouds form and what time of the year that happens. If EVAPORATION occurs “somewhere”, you can bet your life savings that both CLOUDS and PRECIPITATION will occur somewhere else.

    So no CLOUDS are NEVER a positive feedback NO MATTER WHAT, as Dr Bill Shockley would put it in one of his classes. To the best of my knowledge, Bill Shockley never taught climatism

  60. Andy Mayhew says:
    September 28, 2011 at 3:27 am

    If clouds only cool, why are cloudy nights warmer than clear nights? Maybe it’s not QUITE as simple after all?

    Thank you, Andy!

  61. George E. Smith says: “And Bob Tisdale has mentioned that number on many occasions here at WUWT. Something to do with somne “Clausius Clapeyron equation”, so even the modellers agree with that 7% number.”

    I have? Please provide a link.

  62. Erl Happ says: “Thanks for your contribution Bob. I have a different understanding of the phenomenon.
    =
    Whatever suits you Erl… LOL

    Reminds me of that Marx line, I mean Groucho of course: “Those are my principles, and if you don’t like them… well, I have others.”

  63. “”””” Bob Tisdale says:

    September 28, 2011 at 1:50 pm

    George E. Smith says: “And Bob Tisdale has mentioned that number on many occasions here at WUWT. Something to do with somne “Clausius Clapeyron equation”, so even the modellers agree with that 7% number.”

    I have? Please provide a link. “””””

    OOoops ! Gee have I got you and Bill Illis mixed up again Bob ?

    Sorry about that.

  64. “”””” Ed says:

    September 28, 2011 at 1:04 pm

    Andy Mayhew says:
    September 28, 2011 at 3:27 am

    If clouds only cool, why are cloudy nights warmer than clear nights? Maybe it’s not QUITE as simple after all?

    Thank you, Andy! “””””

    Does everybody just post what comes to mind, and never read ANY of the responses ?

    Ed, I’ll tell you exactly what I already told Andy; that you apparently never bothered to read.

    He has it exactly backwards, as I have posted MANY times here at WUWT; maybe I’m just wasting my time.

    What Andy should have said; which IS accurate is that warmer nights tend to be cloudier than cold nights.
    It is warm moist conditions DURING THE DAY that leads to high clouds at night, once the warm moist air rises and cools down to the dew point and clouds form. It still COOLS DOWN on those nights; it does not HEAT UP .

    And the warmer it is during the moist day, the higher that air has to go to get down to the dew point, so the higher the cloud layer forms.

    The warmth during the day produces the clouds; the clouds DO NOT produce the warm night.

    Does it make ANY rational sense at all (with no physics knowledge needed) to believe that the higher a cloud layer is, containing LESS AIR, and LESS MOISTURE and LOWER TEMPERATURE, and LOWER PRESSURE; the more back radiated energy it sends back to the surface.

    By that rationale, it must be those stratospheric Noctilucent clouds; that are pretty much super cold near vaccuums that are most responsible for heating the earth. If those clouds moved oput to the moon would they warm us even more.

    That notion is totally silly, and one doesn’t have to be a scientist to understand that.

  65. Oh boy, this topic makes my head hurt, but I guess I’m a sadist.

    I have more questions than theories, and my first question has two parts:

    1-a) Which is more efficient at moving energy from the surface to space; convection or radiation. I am under the impression that convection is much more powerfull, but it’s a function of available water vapor, so it varies by location.

    1-b) So, comparing the ratio of efficiency to the ratio of geographical areas which favor one versus the other, which dominates globally? My gutt tells me that the tropics, which receive the most energy from the sun, favor convective energy transfer and dominate the energy budget of the planet by a large margin.

    I’m a big fan of the 80-20 rule, so if the margin is anywhere near that ratio, then the tropics are the key. Are there numbers available to support or rebutt my assumptions? I’m sure someone here can help illuminate on that.

    My second question is in regard to clouds versus uncondensed water vapor. Is there a large difference, in the LWIR absorbtion when the same amount of water is present, but in one instance it is condensed and in the second instance it is uncondensed?

    I wonder about that because maybe in the higher altitudes and higher lattitudes, the question should be more in regard to absolute atmospheric water content, rather than cloud versus no cloud. If physical transport of water vapor provides a strong transport mechanism for eneregy, then maybe it is important whether the condensation happens or not. My gutt feeling in this case is that it is important, since the condensation releases the energy to be radiated into space. Even if the cloud then destroys itself, it must draw the energy for evaporation of the cloud droplets from somewhere. Even in daylight, it would have to be from below because the sun doesn’t emit much LW radiation, does it?

  66. Sorry to double post, but I didn’t complete my question in the last paragraph.

    I know that I contradicted myself in that paragraph, and that was my point. I was intending to share some of the pain that this topic causes in my brain and therefore satisify my sadistic nature. muahahah.

  67. Sorry for my apparent inattention. It’s the day job getting in the way.

    Bob Tisdale says: September 28, 2011 at 10:54 am
    And

    TomRude says: September 28, 2011 at 2:46 pm

    Re the ‘Fatal Flaw’ that disqualifies the entire post. And whether I, like Groucho, have a set of principles to suit the moment. Your language is quite aggressive gents. It seems that you are out to do damage.

    I presented graphs with the souces of the data and the time span identified, and you reply with maps of a January and a July–or are they a collection of Januarys and Julys? Please plot the annual variations in the data per hemisphere as I had in my graphs and identify your source.

    on a hemispheric basis, when surface temperature rises and falls, cloud amount rises and falls.

    So far as the latter is concerned: Agreed

    Apologies for the lack of a reference, the maps come from the JRA-25 Atlas at: ttp://ds.data.jma.go.jp/gmd/jra/atlas/eng/atlas-tope.htm They represent recent climatology.

    Bob I will take your word that your graphs are accurate. I don’t need to reproduce them.
    The massive drop in southern hemisphere cloud cover in mid year that seen here http://i56.tinypic.com/23iw8c0.jpg is unrelated to the very moderate decline in sea surface temperature that we see in the southern hemisphere seen here: http://i56.tinypic.com/2d1we2t.jpg

    That cloud loss in the southern hemisphere in mid winter is not a product of reduced evaporation from a cooling ocean but increased downdraft and the expansion of high pressure cells to take in more of the continents including Australia. This shows up on the maps. It indicates that the hemispheres are interactive. The loss of cloud in the southern hemisphere in July is forced from the northern hemisphere. Equally the gain in cloud in January has a lot to do with the cooling of the atmosphere in January that is associated with the strong decline in surface temperature over land in the northern hemisphere.

    The cloud maps I have referenced should be compared with maps of top of atmosphere radiation to see where the energy is coming from. There is a disproportionate amount of energy emitted from the winter hemisphere in the regions occupied by subtropical high pressure cells. It is plainly not coming from the surface but the atmosphere. It’s the Foehn effect on an inter-hemispheric scale.

    Hemispheric data is fine, but in this case we need both a narrower and a broader focus because the behavior of the whole is much influenced by the strange behavior of the parts, and to work that out we need a sub-hemispheric focus.

    As Bob’s graph at http://i54.tinypic.com/mbn7eo.jpg shows global cloud cover is greatest in January when land plus sea surface temperature is least. So the globe as a whole behaves differently to what we see in the individual hemispheres. Did you not notice that contradiction and is that observation not equally relevant? The behavior of the whole is not dictated by the ‘apparent’ behavior of the parts.

    Bob, your argument is flawed, because while it adequately describes the behavior of the parts it does not apply to the whole. Is it fatally flawed? No, just a bit short of being the whole story.

    Could you model this with linear equations? Only if you really understood it in all its regional and seasonal complexity and that is the point of the post. And I think we have just illustrated that point anew. So, no, the post is not fatally flawed.
    .
    Huub Bakker says: September 28, 2011 at 11:00 am Yes, Monckton. I stand corrected, not once but twice.

    George E. Smith says: September 28, 2011 at 12:25 pm
    So winds whisking the newly evaporated H2O molecules away from the surface is essential to rapid evaporation; but it is only the liquid surface Temperature that determines IF evaporation will occur.

    So please stop talking about these entirely peripheral minutiae, like where and how clouds form and what time of the year that happens. If EVAPORATION occurs “somewhere”, you can bet your life savings that both CLOUDS and PRECIPITATION will occur somewhere else.

    If I can add something to your valuable exposition? I observe that the coupled circulation in Antarctica produces a zone of very low surface pressure on the margins of Antarctica that has deepened over the last sixty years. The episodic loss of pressure is accompanied by a smart increase in sea surface temperature that is related to a simultaneous increase in the strength of the westerly winds. But the response in the northern hemisphere to a pressure loss due to the northern coupled circulation is much greater. It is greater because the wind acceleration is much less in the northern hemisphere. It’s what I am talking about in point E above.

    As to whether increased insolation at the surface promotes a commensurate increase in evaporation wherever it occurs that is another matter. Extra watts per meter on water at 6°C versus the same stimulus to water at 28°C. Two different situations. Geography does matter.

    morbidangel says: September 28, 2011 at 1:06 pm

    Ummm… Doesn’t the Foehn Effect have to do with mountains? And does it not say, that since the cloud has disappeared (on the leeward side of the mountain), the air warms and not the other way around.

    So Erl has no idea what a Foehn wind is?

    As I understand it compressive warming on the lee side raises the temperature of the air, Relative Humidity drops, cloud evaporates. The same thing happens on a planetary scale in the winter hemisphere and that’s why I mentioned it.

    Perhaps the former of these two comments posed a question, but the nature of the question was obscure to me.

    George E. Smith says: September 28, 2011 at 5:11 pm
    Does it make ANY rational sense at all (with no physics knowledge needed) to believe that the higher a cloud layer is, containing LESS AIR, and LESS MOISTURE and LOWER TEMPERATURE, and LOWER PRESSURE; the more back radiated energy it sends back to the surface.

    By that rationale, it must be those stratospheric Noctilucent clouds; that are pretty much super cold near vaccuums that are most responsible for heating the earth. If those clouds moved oput to the moon would they warm us even more.

    Reductio ad absurdum
    I like it.

    Gary Swift says: September 28, 2011 at 10:15 pm
    A great series of questions and for the moment I am going to stay right out of it.

    Septic Matthew says: September 28, 2011 at 10:10 am
    Very interesting if we want to describe atmospheric behavior in a narrow band of latitude about the equator. Is it representative of the globe? No. In climate ‘geography’ is vital. The dynamics vary around and up and down the entire globe.

    Paul Vaughan says: September 28, 2011 at 8:41 pm
    Good to see some acknowledgement of the year in the discussion.

    Details please. If you do not provide details all you are saying is that most of the people commenting here are idiots.

  68. why are cloudy nights warmer than clear nights?

    Because the air containing cloud is warm having come from a warm place.Its a gloriously diverse world that we live in and the air is in constant movement.

    Erl, I’m surprised someone from Western Australia would say this.

    It’s quite common here in WA to get cloud from subtropical lows in southern WA.

    A couple of years ago there was total cloud cover for 3 or 4 days in the Goldfields (500 Ks from the coast) in January, usually cloud free and hot. The cloud came from the north ie subtropics. Daytime temperatures were reduced from the usual high 30s to less than 20C. 16C on a couple of days as I recall.

    Even in winter, here in Perth cloudy days are cold days (although warmer nights) irrespective of the direction the clouds come from.

    The reason why N America is as cold as it is in winter, is because air masses from the north originate over land and frozen sea and are dry with few clouds.

  69. Erl Happ says: “Bob I will take your word that your graphs are accurate. I don’t need to reproduce them.”

    I didn’t ask you to reproduce them. I asked you to present the data you are basing your claims on and to present them in the same format. Is your post based on speculation from your visual analysis of the JMA maps or is the post based on your analysis of data? If it’s data, please present it. If you can’t, we’ll assume you’re speculating from your visual analysis of the maps.

    Erl Happ says: “Bob I will take your word that your graphs are accurate. I don’t need to reproduce them.
    The massive drop in southern hemisphere cloud cover in mid year that seen here http://i56.tinypic.com/23iw8c0.jpg is unrelated to the very moderate decline in sea surface temperature that we see in the southern hemisphere seen here: http://i56.tinypic.com/2d1we2t.jpg”

    You have provided nothing to support this.

    The KNMI Climate Explorer does not have land and ocean masks for the ISCCP Cloud Amount data. Does your source of data? If so, please provide a link so that I can confirm your claims.

    And you continued in the next paragraph, “That cloud loss in the southern hemisphere in mid winter is not a product of reduced evaporation from a cooling ocean but increased downdraft and the expansion of high pressure cells to take in more of the continents including Australia. This shows up on the maps. It indicates that the hemispheres are interactive. The loss of cloud in the southern hemisphere in July is forced from the northern hemisphere. Equally the gain in cloud in January has a lot to do with the cooling of the atmosphere in January that is associated with the strong decline in surface temperature over land in the northern hemisphere.”

    Do you have data to support your multiple hypotheses contained in that paragraph? Papers maybe? Or is this also speculation?

    Erl Happ says: “The cloud maps I have referenced should be compared with maps of top of atmosphere radiation to see where the energy is coming from.”

    I find little value in map comparisons without data comparisons. Please provide data that support your claims.

    Erl Happ says: “As Bob’s graph at http://i54.tinypic.com/mbn7eo.jpg shows global cloud cover is greatest in January when land plus sea surface temperature is least.”

    The graph you linked is Land+Sea Surface Temperature data only. It is not a comparison of Global Cloud Amount and Global Land+Sea Surface Temperature. Also, had you inspected that graph a little closer, you would have noted that the Global Cloud Amount peaks in December, not January, and that there is a secondary peak in Global Cloud Amount in March. See what you miss by looking at maps and not data:

    For your reference, here’s a comparison graph of the annual cycle in Global Cloud Amount and Global Land+Sea Surface Temperature:

    Now, in an earlier comment, I asked why the Southern Hemisphere Cloud Amount and its variability was so much greater than the Northern Hemisphere. Was it based on the significantly greater ocean area in the Southern Hemisphere? Ocean surface area is 4 times greater than the land surface area in the Southern Hemisphere. But I was also noting that the Southern Hemisphere SST and Cloud Amount data both peak in February and March, while Southern Hemisphere Land Surface Temperature peaks in January.

    And for reference, here’s a similar comparison with Northern Hemisphere SST, LST and Cloud Amount:

    You continued, “So the globe as a whole behaves differently to what we see in the individual hemispheres. Did you not notice that contradiction and is that observation not equally relevant? The behavior of the whole is not dictated by the ‘apparent’ behavior of the parts.”

    What? The behavior of the globe has to be dictated by the behavior of the hemispheres. It can’t be anything else. Global data is the sum of the hemispheric data. Do you think that the average of the Northern and Southern Hemisphere Cloud Amount data will be different the Global Cloud Amount data?

    It is the same:

    You continued, “Bob, your argument is flawed, because while it adequately describes the behavior of the parts it does not apply to the whole. Is it fatally flawed? No, just a bit short of being the whole story.”

    My argument was that you were once again speculating based on an incomplete analysis. There’s nothing flawed in my argument there. Look at the title of your post: Cloud Cools. You’ve provided nothing in your post that supports this—just speculation. I’ve illustrated why your post is misleading because you are using global Cloud Cover and Global Surface Temperature as the bases for your claims. There’s nothing flawed with that portion of my argument either.

    You asked, “Could you model this with linear equations?

    I have no interest in it and no need to bother.

    You wrote, “Only if you really understood it in all its regional and seasonal complexity and that is the point of the post. And I think we have just illustrated that point anew. So, no, the post is not fatally flawed.”

    The point you attempted to make (that I quoted and discussed in my first comment on this thread) was that the seasonal cycle in global cloud amount was inversely related to the seasonal cycle in global temperatures and therefore clouds provide cooling. Your point and conclusion are misleading at minimum. I have illustrated this in numerous ways. I’ll tell you what. Why don’t I write a post about the misleading and misrepresentative graphs and descriptions in your posts per our discussions on this thread and our discussions on the thread of your last post? We’ll let the readers decide if your analyses/posts are misleading.

  70. erl happ (September 29, 2011 at 12:44 am) requested:
    “Details please.”

    Erl, a communications strategy sensibly addressing the details you crave demands decades, not days. Expectation of instant gratification is grossly impractical. The audience doesn’t even have the base fundamentals needed to construct a sound conceptual framework. This is neither about physics nor “mysterious” physics; it’s about the spatiotemporal sampling framework from which terrestrial signals are aliased & integrated. It will literally take years (probably decades) to educate. Best Regards (…and that’s all for now).

  71. Gary Swift says: September 28, 2011 at 10:15 pm
    1-a) Which is more efficient at moving energy from the surface to space; convection or radiation. I am under the impression that convection is much more powerfull, but it’s a function of available water vapor, so it varies by location.

    You have some good teachers here:
    Cementafriend points to the different types of heat transfer
    George E. Smith says: September 28, 2011 at 12:25 pm points out some home truths about the importance of water vapour.
    Bob Tisdale is a master at extracting and presenting data from lots of sources

    How to evaluate ‘efficient’…….They all work but the only one that actually gets it out of the system and into space is radiation. And generally speaking the radiation that comes from the atmosphere is confined to a particular place on the Earth’s surface.

    One question that might be posed and that is which surface most quickly transfers energy to space and which tends to traps it in the Earth system.

    Dry, dark vegetation free ground or rock heats quickly and radiates fast becoming cold overnight.
    Water traps and holds energy and it does that better in still air but only to the extent that it doesn’t evaporate.
    Heavily vegetated land in the tropics offers the fastest rate of evaporation due to leaf surface area very effectively cooling the surface in a high humidity, low wind velocity environment.
    The daily precipitation cycle results in convection and de-compressive cooling. So, little radiation from here. A massive amount of work is done on a daily basis. But it doesn’t really get the energy out of the Earth system.

    1-b) So, comparing the ratio of efficiency to the ratio of geographical areas which favor one versus the other, which dominates globally? My gutt tells me that the tropics, which receive the most energy from the sun, favor convective energy transfer and dominate the energy budget of the planet by a large margin.

    From surface to top of atmosphere the near equatorial latitudes rely upon convection and de-compressive cooling. Very little radiation is emitted from the top of atmosphere here. This is an environment where energy is used to evaporate water, drive convection, cool by decompression but the energy is not eliminated to space. The elimination only occurs where that same air descends in high pressure cells between 10-40° of latitude. Here air warms in compression and gives off copious amounts of radiation in a dry air environment with little water vapour or cloud (at low levels) and a band of cirrus and stratus in the high troposphere that doesn’t really participate in the circulation. In fact the air tends to move equator-ward. It’s the light grey stuff you see in satellite photos here: http://www.intelliweather.com/imagesuite_specialty.htm

    So, if your question is where does the energy actually get out of the system the answer is here: http://ds.data.jma.go.jp/gmd/jra/atlas/eng/atlas-tope.htm
    Look at the maps showing radiation. Ultimately, the only way that energy leaves the Earth system is by radiation. Anachronistically the winter hemisphere is the more important hemisphere for radiation from the atmosphere. If we are talking radiation from land the important parts are the hot and cold deserts and the waters that are too cool to evaporate. Of course the hot deserts radiate most strongly in the summer hemisphere.

    Philip Bradley says: September 29, 2011 at 4:04 am
    Erl, I’m surprised someone from Western Australia would say this.

    Philip, that is a mysterious comment. I say what I say because I am familiar with the distribution of warm wet air and precipitation: Like here http://policlimate.com/weather/current/gfs_precip.html#picture

    Wet air comes from the tropics and the stuff that gets to WA often does a big sweep over the Indian Ocean, varying with the season of course. There is no place like the ‘Maritime Continent’ i.e SE Asia for delivering water to the atmosphere.

    Ryan Maue has a great collection of maps on his website at http://policlimate.com/weather/index.html and one had an animation of global precipitable moisture but just now I cannot see it.

    Bob Tisdale says: September 29, 2011 at 6:12 am

    Bob, check your data:

    SH cloud increases with surface temperature
    NH cloud increases with surface temperature
    Global Cloud cover varies inversely with surface temperature

    Are we on the same page with these three statements?

    Is your post based on speculation from your visual analysis of the JMA maps

    Yes indeed, and my understanding of the way in which the atmosphere receives energy in one place and gets rid of it in another. It is based upon an understanding of the geography of process in the atmosphere in three planes including the vertical. It is based upon observation of cloud patterns in satellite photography. It is based on an understanding or the coupled circulation at the poles and its effect on wind and sea surface temperature.

    In the end our understandings are all speculative. It’s not a rude word in my book. There are many paths to learning about atmospheric processes and maps establish the geography of process.

    In your explorations in relation to southern hemisphere cloud, it might be useful to look separately at air temperature in the low cloud and the high cloud zone. Say below 700hPa and above 300hPa. And perhaps break it up by latitude a bit. And check out the historical trends in absolute humidity, relative humidity and precipitable water by latitude. Have a look at when the annual minima and maxima in air temperature occur between 0-40°south latitude at each level through to the middle stratosphere.

    Write a post criticizing me if you wish but I don’t guarantee to get involved in the back and forth. I like to think carefully and deliberately about what I say and more haste often means less speed.

  72. Bob, it occurs to me that it might be enlightening to split the Southern hemisphere at say 35° south for analytical purposes in looking at the relationship between surface temperature and percentage cloud over the annual cycle. Where can I access the cloud data?

  73. Erl Happ says: “Bob, check your data:
    SH cloud increases with surface temperature
    NH cloud increases with surface temperature
    Global Cloud cover varies inversely with surface temperature
    Are we on the same page with these three statements.”

    There’s no problem with the data, Erl. I explained the reason for this relationship. The annual variations in Northern Hemisphere Surface Temperature greatly outweigh those of the Southern Hemisphere, making the Northern Hemisphere annual “cycle” dominant. Hence, the annual cycle of the Global Surface Temperature reflects the additional variation in the Northern Hemisphere surface temperature. But with the Total Cloud Amount data, the opposite holds true. The annual variations in Southern Hemisphere Total Cloud Amount greatly outweigh those of the Northern Hemisphere, making the Southern Hemisphere annual “cycle” dominant. And, therefore, the annual cycle in Global Total Cloud Amount reflects the additional variability of the Southern Hemisphere Total Cloud Amount.

    You quoted me, “Is your post based on speculation from your visual analysis of the JMA maps,” but failed to quote me fully. Your reply was, “Yes indeed, and my understanding of the way in which the atmosphere receives energy in one place and gets rid of it in another…”

    The complete question that I asked you was, “Is your post based on speculation from your visual analysis of the JMA maps or is the post based on your analysis of data?”

    I gather this means you have not analyzed cloud cover data or its intricacies or its relationship with surface temperature (which makes sense since you’re questioning the data I’ve presented). So we can conclude from this that your post was conjecture on your part with no basis in data, and, basically, with little to no basis in reality. That’s not a good thing, Erl.

  74. Bob Tisdale says: September 29, 2011 at 9:32 am

    The annual variations in Northern Hemisphere Surface Temperature greatly outweigh those of the Southern Hemisphere, making the Northern Hemisphere annual “cycle” dominant. Hence, the annual cycle of the Global Surface Temperature reflects the additional variation in the Northern Hemisphere surface temperature. But with the Total Cloud Amount data, the opposite holds true. The annual variations in Southern Hemisphere Total Cloud Amount greatly outweigh those of the Northern Hemisphere, making the Southern Hemisphere annual “cycle” dominant. And, therefore, the annual cycle in Global Total Cloud Amount reflects the additional variability of the Southern Hemisphere Total Cloud Amount.

    I agree with this and I agree that the data you have provided is accurate.I don’t need to analyze it on a numerical basis.

    What you need to do is to account for the marked reduction in southern hemisphere cloud cover in mid year rather than to simply say “it happens”. I provide a reason and a description of the process behind that loss of cloud cover. You don’t, other than to suggest that cloud loss relates to surface temperature and evaporation processes and the size of the ocean in the southern hemisphere. The problem is, there is very large reduction in cloud cover in relation to a relatively small reduction in the surface temperature in the southern hemisphere. The southern ocean does not shrink in winter. Your explanation is unphysical.

    It so happens (and you won’t learn this by looking at total cloud data) that:
    1. the high pressure cells of the southern hemisphere represent descending air warming due to compression giving up copious amounts of long wave radiation.This process is enhanced in winter as the JAL maps of cloud cover and OLR show.
    2. The upper troposphere in the region of these high pressure cells contain appreciable ozone.
    3.The presence of ozone and the additional radiation in winter results in a mid year increase in air temperature above 300hPa in a zone that contains copious amounts of relatively thin high altitude ice cloud traveling west and north from an origin in the southern mid latitudes. Any increase in the temperature of the upper troposphere from any source affects this cloud. The upper troposphere in this zone peaks in temperature in winter while the lower troposphere peaks in summer.Hence the marked loss of cloud in this region in winter.
    4 It can be shown that the temperature of the upper troposphere in this region is affected by stratospheric processes and in particular the QBO with its biennial increase in ozone content and temperature in close equatorial latitudes. This tends to be reflected in sea surface temperatures so we know that this cloud impacts the amount of short wave radiation that reaches the surface.In fact, if you look at satellite photography you will see that this high altitude cloud is the most widely distributed and the characteristic type of cloud in the region.

    The really important factor to bear in mind from a study of cloud cover is that globally it peaks in January.The variability in global temperature is greatest between November and March. It is change in cloud cover that is likely responsible. Accounting for inter-annual variation in global temperature requires that we work out why cloud cover varies so much at this time. This is also the time when the variations in ENSO tend to play out. Have you a suggestion as to why this might be so?

  75. Erl Happ says:
    “Your point is well made. I failed to elaborate on the changed humidity relations. And since changed absolute humidity per-se is postulated to be the source of amplification (as well as high altitude cirrus cloud) one needs to be sure that humidity actually increases as the CO2 content of the air increases. The evidence from reanalysis data shows that total precipitable water increases with sea surface temperature but the increase in atmospheric moisture failed to keep pace with SST in successive El Nino episodes between 1978 and 1998. So, relative to the temperature of the sea, precipitable water lagged and one would suggest, with it, cloud cover. However, over the last seven or eight years, as CO2 has continued to increase, precipitable moisture has staged a remarkable recovery.”

    If my point was well made, then that was purely accidental.
    In fact, to criticize my original point, considering only the ocean, then direct sunlight or back radiation cannot warm the air adjacent to the surface, to increase evaporation by lowering the relative humidity. Radiation can only affect the ocean. As you hinted out later in your post, the reason the air is a few degrees warmer than the ocean is that air warms as it descends in high pressure cells. This strongly suggests to me that cloud cover percentage is a fixed function of the geometry of the convective weather patterns much more so than any minor modifications of the back radiation.

  76. Erl Happ says: “What you need to do is to account for the marked reduction in southern hemisphere cloud cover in mid year rather than to simply say ‘it happens’…”

    I believe you miss the point of my comments on this thread: I’ve illustrated how and why your post is misleading. And that’s as far as I need to carry this.

    On that note, I’m finished on this thread, Erl.

  77. Erl Happ says: “The southern ocean does not shrink in winter. Your explanation is unphysical.”

    Oops, I forgot this portion of your last comment. I never provided the explanation you are describing. Do Not Put Words In My Mouth. I have illustrated and described the data. If your explanations do not agree with the data, one might conclude your explanations are incorrect.

  78. Two of the ten with the most holistic understanding of the system and you have to squabble like this. We have another senseless squabble between lucia and his high and mightiness.
    ==============

  79. Kim, its all good. It is vital that ideas and presentations are challenged. I have learned from the exchanges that Bob and I have had on this thread and my next post will be better for it. Nobody gets everything right all the time. Sometimes you may arrive at the right conclusion without having all the ducks properly lined up along the way. Sometimes the ducks appear to line up and the conclusion is wrong.

    Practice ploughing the furrow and time and again. As ones skill improves it gets straighter and deeper.

  80. kim says: @ September 30, 2011 at 6:50 am

    Two of the ten with the most holistic understanding of the system and you have to squabble like this…..
    _____________________________________________________________________
    This is not sad Kim, this is how science is advanced. By discussion, clarifications and the butting of heads.

  81. Bob, I want to make one constructive comment on your climatology graphs:
    The interval 12-1 is missing on your graphs. It can be tagged on either end (as 0 or 13 to fool Excel). Your graphs currently represent only 11 of the 12 month-long intervals of the year. You’re representing 12 nodes, but only 11 connectors – (count them). I made the exact same mistake when I first started looking at this stuff and I regretted it because I had to go back & reformat a lot of multi-panel color-contour graphs that I had gone to a lot of tedious trouble to produce. I ended up deciding it’s very helpful to extend each end of the climatology by a 1/4-cycle (to ease interpretation near arbitrary temporal cycle boundaries). I wish map producers would do the same thing with world maps (to dramatically ease interpretation near spatial cycle boundaries). Best Regards.

  82. Erl, the average annual low-cloud cycle is COMPLEXLY related to the annually shifting bands of ABSOLUTE temperature, pressure, wind, & zonal topography. It’s GREAT that you’re getting people looking at annual cycles, but I want to suggest that you’re pushing too far with your process abstraction oversimplification attempts.

    There’s clearly a ripe opportunity for someone (with a bit of free time) to start a series of posts highlighting animations of the JRA-25 climatologies. A long, slow education campaign (at a pace the average reader can handle) is needed to correct the misconceptions which have accumulated unchecked from excesses of anomaly-based summaries.

    Regards.

  83. Yes, Gail, I’ve calmed down a bit and can see the silver lining that you and Erl both point out. I wish the two could co-operate better, instead of coagulate.
    ===================

  84. AnimPolarWind200hPa

    AnimWind200hPa

    AnimWindZonal

    Please – anyone with a free second – let me know if these work or do not work for you from whatever browser you’re using. If they work for most people, I’ll put up a few more for discussion in future threads.

  85. Paul,
    That low pressure zone appearing in the north Pacific and the Atlantic in January is a signature of the Arctic Oscillation (NAM) and the North Atlantic Oscillation as it manifests under the impact of the coupled circulation of the stratosphere and the troposphere over the Arctic. It is the NH version of the low pressure zone that surrounds Antarctica. The relative strength of those NH and SH low pressure zones is an indicator of where the climate is driven from. Each of those low pressure zones represents ozone being driven into the troposphere affecting cloud cover and surface temperature. It is the change in the strength of those pressure zones that represents climate change in action. Manifestly it is the Antarctic that drives the system. Paradoxically the Arctic is very influential Nov-March.

  86. A few more:

    AnimHeating

    AnimWaterVaporFlux_
    (column integrated water vapor flux with their convergence)

    AnimWind850hPa_

    AnimPolarWind850hPa

    Tip: TinyPic says image must be under 5MB, but seems to actually mean 4.75MB. 4.70MB & 4.69MB worked, but 4.89MB & 4.77MB did not — e.g. had to trim off a little more than just non-essentials of “AnimWaterVaporFlux_” – and tinypic demanded minor trimming of “AnimWind850hPa_”.

    Erl: May & November really stand out (on average) as hard, qualitative topography/flow switches.

  87. Paul Vaughan says: October 1, 2011 at 9:10 pm
    Erl: May & November really stand out (on average) as hard, qualitative topography/flow switches.

    And that can be related to the polar circulations. The Arctic cuts in affecting the strength of the Antarctic circulation in November and runs till March.

    What these maps do not reflect is change over time. There is a big difference in the circulations pre and post 1978 when Antarctic 10hPa temperatures peaked.

    It would be good to have accurate descriptions of what the data actually represents because that is not always obvious to people like myself untrained in meteorology.

  88. Just acknowledge my volunteer animation work & JRA-25 Atlas:

    “Credit of the JRA-25 Atlas
    The source of the JRA-25 Atlas should be duly acknowledged in papers, publications, press releases or other communications regarding the Atlas.
    Example: The JRA-25 Atlas data used for this study are provided from the cooperative research project of the JRA-25 long-term reanalysis by the Japan Meteorological Agency (JMA) and the Central Research Institute of Electric Power Industry (CRIEPI).”

    http://ds.data.jma.go.jp/gmd/jra/atlas/eng/atlas-tope.htm

    Anim2mT

    AnimPrecipitableWater

    Regards.

  89. You’ll likely disagree with their interpretation Erl:

    Cold causing record Ozone loss over Arctic: scientists (Sunday Oct. 2)

    http://www.ctv.ca/CTVNews/TopStories/20111002/arctic-ozone-hole-111002/

    “Scientists say an unprecedented ozone “hole” opened up above the Arctic last year, caused by an unusually prolonged period of extremely low temperatures.

    A NASA-led study says the amount of ozone destroyed was comparable to that seen in some years in the Antarctic, where an ozone “hole” has formed each spring since the mid 1980s.
    […]
    They found that at some altitudes, the cold period in the Arctic lasted more than 30 days longer in 2011 than in any previously studied Arctic winter, leading to the unprecedented ozone loss.

    This year’s ozone loss occurred over an area considerably smaller than that of the Antarctic ozone holes.

    That’s because the Arctic polar vortex, a persistent large-scale cyclone within which the ozone loss takes place, was about 40 per cent smaller than a typical Antarctic vortex.”

  90. Paul Vaughan says: October 2, 2011 at 8:08 pm
    Paul, I think that I can agree with what they say.

    Low temperatures in the upper stratosphere and at the surface and ozone loss go hand in hand with increased surface pressure (low Arctic Oscillation Index) and enhanced night jet activity bringing erosive nitrogen oxides from the mesosphere into the stratosphere.

    “the Arctic polar vortex, a persistent large-scale cyclone within which the ozone loss takes place, was about 40 per cent smaller than a typical Antarctic vortex.”

    And that is where the NOx is active.

    If they had gone on to say that the ozone loss was due to chlorofluorocarbons from aerosols and refrigerators then I would have disagreed.

    The word ‘vortex’ is used to refer to two different things but here I think they are using it correctly to refer to the night jet in the stratosphere. The other use refers to the surface low pressure systems where the polar easterlies engage the westerlies that is more properly called the ‘polar front’. Hence ‘polar outbreaks’ when pressure is high and the easterlies ‘break out’ swinging across the Great Plains all the way to New Orleans.

    In the last ten years the lowest AO has been recorded in January February in 2010 and 2011. No other years come close.

  91. “Rex says he understands the need for budgetary constraint, but takes issue with recent statements by Environment Canada official Karen Dodds who said there is “redundancy” in the existing Canadian networks that can be eliminated.

    “There is no redundancy,” says Rex, noting that the current Canadian measurements are essential to the international ozone monitoring program.

    “The scientists in Environment Canada are bright guys,“ he says. “They have never wasted money by doing redundant measurements.”

    Ozone hole said to be due to the work of man. These guys don’t want to know about NOx from the mesosphere.

  92. Erl, you’ll see “How to create an animated PNG?” over here:

    http://www.truekolor.net/learn-how-to-create-an-animated-png/

    That links you to the APNG Anime Maker download here:
    http://sites.google.com/site/cphktool/apng-anime-maker/APNGAnimeMaker.rar?attredirects=0&d=1 (don’t click this unless you want to do the download)

    It’s lightweight simple software.
    You just “Open” the images as a batch & “Save”.

    Tip: Throw them all in a single folder beforehand [just drag-&-drop from the web to the folder] so you can click somewhere (anywhere) inside APNG Anime Maker’s “Open” browse-box & ‘select-all’ (Ctrl-A).

    Optional Tip: I’ve been renaming the climatology image files “01”, “02”, “03”, … “12” so I can sort alphanumerically and spin through them at my own speed (with keyboard arrow keys) using Windows Picture and Fax Viewer (which cycles inside a folder).

    A google search will turn up lots of alternative approaches. GIF files take up less memory, but PNG offers much better quality for most of the climatologies.

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