Guest post by Erl Happ
Here’s a hypothetical:
Let’s imagine that we have an atmosphere of two parts. The first 10 km of the atmosphere has no greenhouse gas. The second 40 km has a greenhouse gas incorporated.
In the lower layer there is water vapor and clouds that come and go according to the temperature of the air.
Let’s consider that there is an impermeable membrane over the surface preventing the interchange of moisture with the atmosphere. No precipitation of moisture from the atmosphere falls to the surface.
Now, set this planet spinning in space around a sun in such a way that the polar sections experienced permanent night for part of the year so that the entire depth of the atmosphere (both layers) within the polar night region cool down and a gradient of ever diminishing temperature occurs all the way from the surface to the top of the atmosphere, the entire 50 kilometers.
Parts of the planet would be warm and parts would be cold. Ascent and descent of the atmosphere is forced by these thermal differences but the ascent is usually confined to just a few kilometers in elevation.
Now, let’s imagine that the greenhouse gas is water soluble. That part of the atmosphere that contains the least water is within the polar night because it is coldest, so the greenhouse gas attains a higher concentration there.
That greenhouse gas absorbs long wave radiation from the planet. This sets up a convective circulation within the polar night that spins the greenhouse gas rich air away from the pole towards the margins of the polar night. Remember that temperature descends all the way from the bottom to the top of the atmosphere within the polar night and this promotes convection throughout the entire profile. In fact the two layers act as a coupled circulation.
So, greenhouse gas descends into the near surface layer on the margins of the polar night that hitherto was entirely free of greenhouse gas. This causes the air on the margins of the polar night to warm as it descends. Surface pressure falls away in this region.
Now, if this circulation came and went, we would see clouds come and go on the margins of the polar night as the air alternatively cooled and warmed.
Now, let us imagine that there is a wind that blows from the polar night towards the equator that carries greenhouse gas towards the equator warming the air and causing cloud to disappear.
Now, let us introduce land and sea in the winter hemisphere and assume that the air on the margins of the polar night descends preferentially over the sea. We would then expect the greenhouse gas to be concentrated in the atmosphere over the sea. This would give rise to a pattern of warm and cool air, clouds in the cool zone and none in the warm zone. A cloud free path would be set up that ran from the warmer margins of the night zone towards the equator. The cloud would come and go as the coupled circulation waxed and waned.
The lower of the two layers would show zones of warmed air like the map below.
Figure 1
And under the influence of the wind that blows towards the equator we might see a pattern of sea surface temperature like this:
Figure 2
Now, let’s imagine that there is an insidious chemical generated in the rarefied atmosphere above both layers that has an affinity for the greenhouse gas and this chemical is intermittently trickled into the top of the layer containing the greenhouse gas and this occurs over the pole. This is accomplished by a thing we call the ‘night jet’. Accordingly, the greenhouse gas content of the night zone would wax and wane causing a fluctuation in cloud and the temperature of the sea.
If we wished to know what was changing the weather and the climate we would have to look at what changes the trickle rate and what causes the polar circulation to wax and wane.
We look closely and find the ‘night jet’ is active when surface pressure is high.
We discover that the pressure is high when the sun is less active.
When the sun is active pressure is low and the night jet is less active, the greenhouse gas content builds up, the temperature of the column increases and the convective circulation goes into overdrive. And the clouds disappear.
And the temperature of the polar stratosphere might look like this:
Figure 3
So, in this circumstance the planet warms. Does anyone recognize the origin of the great Pacific Climate Shift of 1976-8?
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Friends:
I do not like “thought experiments” because they are usually so divorced from reality that they are often misleading in ways that cannot be known. However, I interject at this point in this discussion in hope of helping by asking all sides to consider a point raised by Crispin in Waterloo at August 20, 2011 at 11:06 pm .
Erl Happ says there is sufficient liquid water in the stratosphere to enable significant solution of ozone.
Leif Svalgaard says there is no liquid water in the stratosphere.
The point of dispute is the meanings of “sufficient” and “no”.
But the post from Crispin in Waterloo provides information that may resolve the dispute. In it he says;
“My point is that transparent-to-the-eye air can have a great deal of water in it, not in the form of water vapour. Even at high altitude, droplets do not necessarily freeze but can remain supercooled, and do not have to evaporate, depending on lcoal (sic) conditions. It is often mistated that air contains water vapour and cloud/rain drops only. Visible light readings of cloud cover from satellites do not give an accurate assessment of all cloud cover because all the water droplets below 0.1 microns are invisible in normal light.”
Perhaps the impasse of Erl Happ and Leif Svalgaard would be overcome by consideration of the possibility of microdroplets in the stratosphere as is suggested by Crispin in Waterloo. If so, then the discussion could consider the degree of ozone solution which is possible instead of the ‘all or nothing impasse’ which now exists.
Is the degree of ozone solubility possibly significant (as Erl Happ suggests) or certainly negligible (as Leif Svalgaard asserts) if such microdroplets exist in the stratosphere? The answer would depend on the amount of liquid water in such microdroplets which may possibly exist in the stratosphere. So, can an empirical and/or theoretical upper bound be applied to that amount?
Richard
Joel Heinrich says:
August 21, 2011 at 2:15 am
Joel, the counter westerlies at altitude blow opposite to the surface winds. The cloud that is affected is mid to high altitude, not surface cloud.
Bomber_the_Cat says:
August 21, 2011 at 3:17 am
Walks into the room, drops the bomb and walks out. Aptly named. No doubt this behavior gives you a feeling of superiority.But why not ask for clarification?
Leif Svalgaard says:
August 21, 2011 at 4:08 am
“There is no liquid water in the stratosphere, thus your argument fails right there.”
No, your wrong. The argument does not ‘hang’ on the presence of water vapour in the stratosphere’ at all. It would make not the slightest jot of difference were there no water in any form in the stratosphere. The dynamics of the coupled circulation at the poles does not depend upon their being an enhanced level of ozone in the polar stratosphere from whatever cause. It depends upon the relative presence or absence of a long wave absorber (ozone) in an atmospheric column that, like the troposphere, gets colder with altitude through the troposphere, AND the bulk of the stratosphere. So in exactly the same way as convection occurs in the troposphere with say the release of latent heat of condensation, the warming of the polar atmosphere by ozone promotes a convectional circulation that encompasses the entire atmospheric column. That’s why it is referred to as being a ‘coupled’ circulation of the troposphere and the stratosphere.
And that is the crux of the matter.
You fall short of acknowledging the effect of the coupled circulation (that manifestly exists) on temperature, geopotential height, surface pressure, relative humidity and cloud cover on the margins of the circulation.
So your comment is deficient in both observation and logic.
But, is there an enhanced level of ozone in the polar stratosphere? It depends primarily upon the strength of the night jet which is most active under a high pressure regime. That is when the Arctic and the Antarctic Oscillation Indexes are negative and at this moment we have that situation. So, there is currently a large core of low ozone values above the poles as we see here:http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_o3mr_30_nh_f00.gif and here http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_o3mr_30_sh_f00.gif
When polar pressure is low, the night jet is weak and ozone builds up in the polar stratosphere driving a stronger coupled circulation. That has the effect of lowering surface pressure on the margins of the circulation and incidentally reducing cloud cover.
I must admit to being a little lost…but you probably don’t need “liquid water” in the stratosphere to ‘lose’ ozone. Solids would be just as good: Polar Stratospheric Clouds.
As Crispin in Waterloo pointed out, there a whole load of physico-chemical stuff happening with real-world combustion systems (including the atmosphere) and things get pretty messy. It’s one of the reason the rate constants for the chemistry are so hard to pin down accurately, and last time I looked (admittedly 20 years ago 🙂 the gas phase stuff was hard enough, without invoking heterogenous pathways which inevitably play a major role (in the lab stuffing up the experiment, and out in the real world, doing what they’ve always done).
Steven Mosher: surely the UV absorption from ozone is what’s warming things up in the stratosphere, CO2 is small fry?
But back to the thesis: Erl, it sounds like you are trying to come up with a mechanism for changes in cloud cover and invoking ozone in the stratosphere? Doesn’t that sort of reasoning come down to which comes first: chicken or egg? The climate system is coupled every way you look – the longer the timescale, the harder it is to factor in all the relevant processes, the shorter the timescale, the more likely you think some change is significant when it’s not. But the killer question remains “Are human emissions of CO2 doing (or going to do) something so bad we need to reduce our emissions of CO2 right now?”.
Green Sand says:
August 20, 2011 at 2:27 pm
“Many people with more comprehension than I have stress that: Water vapor is THE greenhouse gas.”
Gases and liquids are both fluids. Liquid water has all the properties that distinguish greenhouse gases from non-greenhouse gases. The biggest differences in greenhouse properties between water vapor and liquid water is that the liquid phase is opaque to all frequencies of thermal radiation where the gas phase has a bunch of non-absorptive holes in it. The other big difference is there’s more water in just the first meter of the ocean than there is in the entire column of air above it.
So long as the earth is 70% covered by a 4000 meter deep liquid ocean with an unfrozen surface that ocean itself does all the heavy lifting when it comes to greenhouse warming.
Since this article is about thought experiments think about running a GCM where the earth has all the same greenhouse gases but has no ocean. Imagine that continents cover 100% of the surface. I firmly believe that such a world would become frozen from pole to equator within just a few years. The first winter snowfall would never melt in the spring due to high albedo reflecting away all the sunlight and this would rapidly advance towards the equator with each passing winter.
It’s the global ocean that keeps the earth above freezing not the atmosphere! The atmosphere is a bit player on a water world where its most significant contribution is merely establishing a surface pressure that raises the boiling point of water well above its freezing point so that a liquid ocean has a 100C temperature range in which it can remain liquid.
erl happ says:
August 21, 2011 at 6:15 am
The argument does not ‘hang’ on the presence of water vapour in the stratosphere’ at all. It would make not the slightest jot of difference were there no water in any form in the stratosphere.
First of all: you are not talking about water vapor, but liquid water. It is nonsense to say that ozone is soluble in water vapor [which was my original point]. So if you think what you said was not nonsense, then you imply that you are talking about liquid water.
This is what you said:
“Now, let’s imagine that the greenhouse gas is water soluble. That part of the atmosphere that contains the least water is within the polar night because it is coldest, so the greenhouse gas attains a higher concentration there.”
Here you assert that the higher concentration of ozone there is due to it being dissolved in liquid water elsewhere.
“That greenhouse gas absorbs long wave radiation from the planet. This sets up a convective circulation within the polar night that spins the greenhouse gas rich air away from the pole towards the margins of the polar night.”
Here you say that the higher concentration of ozone brought about by the lack of liquid water sets up a circulation.
“Remember that temperature descends all the way from the bottom to the top of the atmosphere within the polar night and this promotes convection throughout the entire profile. In fact the two layers act as a coupled circulation.”
Here you say that the temperature decreases all the way from the surface to the top of the atmosphere. ‘Top’ includes the thermosphere where the temperature even in the deep polar night is above 500 K. If you by top of the atmosphere mean the top of the stratosphere, then we are in contraction with yourself when you claim that there is a temperature inversion at the tropopause.
Your way out is to remove the statements I just cited, then as you now claim “it would make not the slightest jot of difference were there no water in any form in the stratosphere”. That is all.
Richard S Courtney says:
August 21, 2011 at 5:43 am
Lots of good common sense in that comment but we should not get hung up on this water vapour thing.
I have put forward a conceptual exercise. It is obviously not a description of reality. Neither Leif or anyone else can not dismiss the exercise on that basis but it seems that they think its the virtuous thing to do. I guess it represents a failure to engage, to wonder.
Leif:
Good ol Wikipedia:
Polar stratospheric clouds are classified into three types Ia, Ib and II according to their chemical composition.
Type I clouds contain nitric acid and water.
Type Ia clouds consist of crystals formed from nitric acid and water.
Type Ib cloud droplets additionally contain sulfuric acid and are present in the form of supercooled ternary solution.
Type II clouds consist of water ice only.
I’m told they deplete ozone.
erl happ says:
August 21, 2011 at 7:38 am
I have put forward a conceptual exercise. It is obviously not a description of reality.
such exercises are useful if they contain enough of reality to be meaningful, otherwise they are futile.
I notice that you fail to engage and respond to my analysis of 7:06 am.
erl happ says:
August 21, 2011 at 7:46 am
I’m told they deplete ozone.
Not by the ozone being dissolved by the clouds [and still existing inside the water].
erl happ says:
August 21, 2011 at 7:46 am
Good ol Wikipedia:
Polar stratospheric clouds (PSCs), also known as nacreous clouds (pronounced /ˈneɪkrɪəs/, from nacre, or mother of pearl, due to its iridescence), are clouds in the winter polar stratosphere at altitudes of 15,000–25,000 meters (50,000–80,000 ft). They are implicated in the formation of ozone holes;[1] their effects on ozone depletion arise because they support chemical reactions that produce active chlorine which catalyzes ozone destruction, and also because they remove gaseous nitric acid, perturbing nitrogen and chlorine cycles in a way which increases ozone destruction.[2]
Not by dissolving the ozone into the clouds. When you cite, don’t omit the essential point.
erl happ says:
August 21, 2011 at 7:46 am
I’m told they deplete ozone.
Here is an animation of how the nitric acid+water crystals destroy ozone
http://www.shsu.edu/~chemistry/ESC440/psc.gif
Not by the ozone being water soluble.
Dixon says:
August 21, 2011 at 6:48 am
“Doesn’t that sort of reasoning come down to which comes first: chicken or egg? The climate system is coupled every way you look ”
Not when you are looking at a dynamic that seems to take 130 years to run a cycle in the southern hemisphere and about thirty in the northern. And not when its an open system that is influenced by the solar wind.
Leif Svalgaard says:
August 21, 2011 at 7:06 am
You persist in criticizing me because the model that I put forward is not a proper representation of reality.
Go for it. It does you no credit.
But think of this. In the industrial generation f ozone it is necessary to first dry the air by reducing its temperature to minus 80°C. Does that air contain any more or less ‘water’ before or after?
In any case its a perfiddling and irrelevant point, and not something to use to invalidate the observations in relation to pressure, geopotential height and relative humidity on the margins of the coupled circulation or the importance of the night jet in controlling ozone in the polar stratosphere.
erl happ says: August 20, 2011 at 9:13 pm
According to some: Water vapor in the stratosphere has two main sources. One is transport of water vapor from the troposphere which occurs mainly as air rises in the tropics. The other is the oxidation of methane which occurs mostly in the upper stratosphere.
Espen says: August 21, 2011 at 2:19 am
There has been an increase in stratospheric water vapor, and the El Chichon and Pinatubo eruptions are likely causes. This also means that the stepwise stratospheric cooling seen e.g. here: http://www.ssmi.com/data/msu/graphics/tls/plots/sc_Rss_compare_TS_channel_tls_v03_3.png (note that the warming due to the volcanoes are followed by a decrease to below the previous temperature) may have been caused partly by these volcanoes (so that stratospheric cooling “proves” AGW theory is not as well-supported as many advocates claim).
See: http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442(2003)016%3C3525%3AAGSOVE%3E2.0.CO%3B2#h1
The spikes in the lower stratosphere temperature record certainly correlate well with the drop in Apparent Atmospheric Transmission of Solar Radiation associated with the El Chichon and Pinatubo eruptions:
http://www.esrl.noaa.gov/gmd/webdata/grad/mloapt/mlo_transmission.gif
And the stepwise nature of the changes is visually apparent and apparently well recognized, e.g. “Stepwise changes in stratospheric temperature”:
http://europa.agu.org/?uri=/journals/gl/98GL51534.xml&view=article
There appears to be ample evidence that Volcanoes release a lot of water vapor, i.e.; “Water vapor constitutes 70 to 95 percent of all eruption gases.”
http://volcanology.geol.ucsb.edu/gas.htm
and “A frost point hygrometer designed for aircraft operation was included in the complement of instruments assembled for the NASA U-2 flights through the plume of Mount St. Helens. Measurements made on the 22 May flight showed the water vapor to be closely associated with the aerosol plume. The water vapor mixing ratio by mass in the plume was as high as 40 x 10–6. This compares with values of 2 x 10–6to 3 x 10–6outside of the plume.”
http://www.sciencemag.org/content/211/4484/823.abstract
Additionally there does appear to be research that shows “a stratospheric cooling in regions of H2O increase, of magnitude similar to that due to stratospheric ozone loss indicating a significant additional cause of observed stratospheric temperature decreases. Radiative forcings are derived and it is found that global average radiative forcing due to stratospheric water vapour changes probably lies in the range 0.12 to 0.20 Wm(-2)decade(-1). This could have more than compensated for the negative radiative forcing due to decadal ozone loss.”
http://cel.webofknowledge.com/InboundService.do?SID=N18eGOad4FOh1mIa21f&product=CEL&UT=000166291200047&SrcApp=Highwire&Init=Yes&action=retrieve&SrcAuth=Highwire&customersID=Highwire&mode=FullRecord
This paper found that “Stratospheric water vapor concentrations decreased by about 10% after the year 2000. Here we show that this acted to slow the rate of increase in global surface temperature over 2000–2009 by about 25% compared to that which would have occurred due only to carbon dioxide and other greenhouse gases. More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% as compared to estimates neglecting this change. These findings show that stratospheric water vapor is an important driver of decadal global surface climate change.”
http://www.sciencemag.org/content/327/5970/1219.full#ref-3
Here is a stratospheric water vapor time series
http://www.esrl.noaa.gov/gmd/images/water_vapor.jpg
based on NOAA’s Earth System Research Laboratory balloon program:
http://www.esrl.noaa.gov/gmd/ozwv/wvap/
The program measures Water Vapor Vertical Profiles in three locations, including Boulder, Colorado;
http://www.esrl.noaa.gov/gmd//webdata/ozwv/wvap/bld/iadv/2011-06-29.A.png
ftp://ftp.cmdl.noaa.gov/ozwv/water_vapor/Boulder_New/
Lauder, New Zealand;
http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=LDR&program=wvap&type=vp
ftp://ftp.cmdl.noaa.gov/ozwv/water_vapor/Lauder_New/
and Hilo, Hawaii:
http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=HIH&program=wvap&type=vp
ftp://ftp.cmdl.noaa.gov/ozwv/water_vapor/Hilo_New/
This paper, “Stratospheric water vapor trends over Boulder, Colorado: Analysis of the 30 year Boulder record”;
http://www.agu.org/pubs/crossref/2011/2010JD015065.shtml
notes that there is a “well-examined but unattributed 1980–2000 period of stratospheric water vapor growth. Trends are determined for five 2 km stratospheric layers (16–26 km) utilizing weighted, piecewise regression analyses. Stratospheric water vapor abundance increased by an average of 1.0 ± 0.2 ppmv (27 ± 6%) during 1980–2010 with significant shorter-term variations along the way. Growth during period 1 (1980–1989) was positive and weakened with altitude from 0.44 ± 0.13 ppmv at 16–18 km to 0.07 ± 0.07 ppmv at 24–26 km. Water vapor increased during period 2 (1990–2000) by an average 0.57 ± 0.25 ppmv, decreased during period 3 (2001–2005) by an average 0.35 ± 0.04 ppmv, then increased again during period 4 (2006–2010) by an average 0.49 ± 0.17 ppmv. The diminishing growth with altitude observed during period 1 is consistent with a water vapor increase in the tropical lower stratosphere that propagated to the midlatitudes. In contrast, growth during periods 2 and 4 is stronger at higher altitudes, revealing contributions from at least one mechanism that strengthens with altitude, such as methane oxidation. The amount of methane oxidized in the stratosphere increased considerably during 1980–2010, but this source can account for at most 28 ± 4%, 14 ± 4%, and 25 ± 5% of the net stratospheric water vapor increases during 1980–2000, 1990–2000, and 1980–2010, respectively.”
No conclusions, just a bunch of info and lots more to be learned.
Leif Svalgaard says:
August 21, 2011 at 7:59 am
If there is water there I imagine it will dissolve ozone in exactly the same way as at the surface. We might pretend that we know what is happening but at the end of the day its all theory.
erl happ says:
August 21, 2011 at 8:39 am
You persist in criticizing me because the model that I put forward is not a proper representation of reality.
I’m criticizing your statements that are incorrect in the situation at hand, namely that ozone is dissolved in water in the stratosphere and that that is the cause of the circulation. Just remove those statements and move on.
Leif Svalgaard says:
August 21, 2011 at 7:49 am
I say: I have put forward a conceptual exercise. It is obviously not a description of reality.
You say: Such exercises are useful if they contain enough of reality to be meaningful, otherwise they are futile.
What is the point of the conceptual exercise relating to a two layer atmosphere with all the greenhouse gas in the second layer? Yes, a conceptual exercise, not a description of reality as some, including Leif, the Bomber and Pascvacs would like to pretend, and they dismiss the exercise on that basis. Hey guys, relax. Pretend you are at the pictures.Come along for the ride.
Here is my point: Consideration of my posited two layer atmosphere hints at the relative efficacy of ozone and carbon dioxide as greenhouse gases.
Consider the mid latitudes. Despite the fact that we get lots of water vapour and cloud with 380ppm CO2 in the troposphere declining to 250ppm at the 25km elevation in the stratosphere, nevertheless we see a temperature inversion from 100hPa or 10km upwards. That inversion (the tropopause is its start) is due to the presence of ozone. It creates the stratosphere. Just how good is all that water vapour, cloud and CO2 as an absorber of long wave radiation from the Earth when the addition of a mere 2-15 ppm of ozone can produce this temperature inversion that we know as the stratosphere? And what difference will it make if the level of CO2 were to double? Well we can work that out too, because there is no evidence that the presence of ozone above 100hPa makes one jot of difference to the temperature of the air below the tropopause. We get this big heating effect from 2-15ppm ozone. At 380ppm isnt CO2 pretty well represented already?
There is obviously a down-welling effect from the stratosphere but it is completely ineffective in changing the temperature profile. The influence of convection is too strong a countervailing force. See: http://climatechange1.wordpress.com/2009/04/24/the-gaping-hole-in-greenhouse-theory/
Consider that at elevations below the middle stratosphere the temperature inversion is due mainly to ozone absorption of long wave radiation from the Earth, not UVB or very short wave radiation from the sun. The presence of oxygen ensures that all the very short wave radiation is absorbed in the upper stratosphere. So ozone is not created in the lower stratosphere, it drifts down and its concentration gradually diminishes with elevation into the upper troposphere with the increasing presence of water vapour/ice/water droplets, that limits its persistence the most dramatic illustration of that being at the equator (generally acknowledged but not by Leif).
So, it must be concluded that ozone is doing a much better job of absorbing OLR than CO2 or water vapour. No doubt Leif could do some calculations to tell us the energy that is absorbed according to the energy available in the spectral bands that are absorbed. He is very good at that sort of thing.
Consider the temperature of the atmosphere within the polar night. No short wave radiation there, no UVB and the temperature of the stratosphere is driven solely by ozone absorption of long wave radiation from the Earth. It can be observed that ozone concentration is directly related to air temperature and geopotential height. At the moment with a very active night jet, ozone is depleted and the core is very cold: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_t30_sh_f00.gif
But the point of this little post is that that absorption of long wave radiation in the polar stratosphere is sufficient to set up a circulation of the entire column of the so called troposphere (where is the tropopause when temperature declines with altitude all the way to 5hPa?) and the stratosphere together so that ozone descends into the troposphere at 60-70° south where it so heats the troposphere (75% of the atmosphere) that we see the lowest surface atmospheric pressure on the entire planet. The CO2 and the water vapour are there all the time but the ozone makes this extraordinary difference. And it is this ozone in the troposphere (distributed equator-ward by the high altitude counter westerlies) that alters cloud cover.
And here is the critical bit. The amount of ozone over the pole and the strength of the coupled circulation is highly variable. Historical variability can be judged according to the strength of the north westerly winds that respond to the difference in the atmospheric pressure between 30°south latitude and 60°south latitude. Look here for the observational record in relation to wind http://www.seafriends.org.nz/issues/global/fletcher.htm
We have to go back to 1880 to see the wind strengths we have today. Increasing wind speed since about 1920 represents a loss of cloud cover because both wind speed and cloud cover are related to the change in pressure on the margins of Antarctica.
By the way, if your interest is ENSO the trades and the westerlies vary together.
Finally, in relation to the cloud cover dynamic in the subtropics: When the surface in the subtropics heats by one degree Celsius the air at 200hpa in the upper troposphere, where there tends to be a lot of fine cirrus cloud, warms by three degrees. Which is chicken and which is egg? I leave it to you to work that one out.
Early in my explorations of the atmosphere I noticed that there is a long wave radiation signature in the stratosphere over the south east Pacific where the water is very cold and little heat is lost via evaporation. That told me that the lower stratosphere is a test bench for greenhouse theory. Take ozone and put it into the troposphere and you must lose cloud. Vary the amount of ozone introduced to the troposphere over time and you have a climate forcing.
erl happ says:
August 21, 2011 at 8:44 am
If there is water there I imagine it will dissolve ozone in exactly the same way as at the surface.
There is no water there. There are crystals formed from nitric acid and water: HNO3+3H2O, and they do not dissolve ozone. What happens can be seen here: http://www.shsu.edu/~chemistry/ESC440/psc.gif
Your imagined process is not what happens.
Leif Svalgaard says:
August 20, 2011 at 2:27 pm
……. produce a graph that on the X-axis has solar activity and on the Y-axis pressure.
I have a different one, but then the AGW people wouldn’t wish to see the connection.
http://www.vukcevic.talktalk.net/AtmPress.htm
Oceans absorb energy, currents move it along, heat is realised at a cooler time and place, and the atmospheric pressure responds.
Leif Svalgaard says:
August 21, 2011 at 8:49 am
I’m criticizing your statements that are incorrect in the situation at hand, namely that ozone is dissolved in water in the stratosphere and that that is the cause of the circulation. Just remove those statements and move on.
I’d say that’s nit picking.
“and that that is the cause of the circulation” You misread me.
What I said was: “That greenhouse gas absorbs long wave radiation from the planet. This sets up a convective circulation within the polar night that spins the greenhouse gas rich air away from the pole towards the margins of the polar night.”
erl happ says:
August 21, 2011 at 9:16 am
I’d say that’s nit picking.
The truth is never not picking.
What I said was: “That greenhouse gas absorbs long wave radiation from the planet. This sets up a convective circulation within the polar night that spins the greenhouse gas rich air away from the pole towards the margins of the polar night.”
You only get the circulation if there is a difference in concentration which you claimed was caused by ozone being dissolved in water. So, i did not misread you. Let me quote again:
“Now, let’s imagine that the greenhouse gas is water soluble. That part of the atmosphere that contains the least water is within the polar night because it is coldest, so the greenhouse gas attains a higher concentration there. That greenhouse gas absorbs long wave radiation from the planet. This sets up a convective circulation within the polar night that spins the greenhouse gas rich air away from the pole towards the margins of the polar night. Remember that temperature descends all the way from the bottom to the top of the atmosphere within the polar night and this promotes convection throughout the entire profile.”
You have a chain of inferences, each step depending on the previous one.
Leif Svalgaard says:
August 21, 2011 at 9:24 am
“You only get the circulation if there is a difference in concentration ”
I would suspect that the fall of temperature with altitude through the stratosphere would also assist.
But, this is something worth discussing. I do not profess to know the ins and outs of why this circulation is as strong as it appears to be and, in the case of Antarctica persists all year even though the temperature gradient in summer is the reverse of that in winter (stratosphere warms with increasing elevation).
The manifestation in the troposphere is the cells of increased geopotential height at 200hPa and lower surface atmospheric pressure. These are evident in both hemsipheres all year round.
I don’t know that anyone could tell you why the coupled circulation behaves as it does. There is a bit to be learned in this respect. Its absolutely unique in the atmosphere.
But I do suspect that night jet activity is somewhat diminished in the summer hemisphere especially in the Arctic and this does set up a gradient of increasing ozone polewards of 60° of latitude and that would help.
Certainly the short term variations in stratospheric temperature occur in the Arctic in winter but the months of high variation in temperature represent a longer period in the southern hemisphere.
Come to think of it, the few occasions where the circulation appears to stall completely happen in winter. At any rate, that is when the big variations in temperature occur. Perhaps the meteorologists could chip in with their knowledge of what they call ‘blocking highs’.
I wonder if anyone has data on ozone in the Arctic troposphere over time?
Time for bed.
We do have a way to measure the Arctic influence on the climate of most of the N. Hemisphere (north of 20 degrees.)
This is typically referred to as the Arctic Osciliation. I would look at whether ozone concentrations in the arctic regions correspond to the AO index and how. This would be a verifiable method to see if your theory is sound in any fashion. The graphs you show are basically causes of various levels of the AO and how it pulses. It is curious that recent cool phases of the AO and the lower ozone concentration in the arctic seem to correlate so to speak.
And even if there is a correlation there, remember causation is so much more difficult. I think you hinted at this earlier, but does the tail wag the dog or does the dog wag the tail? I think until you figure that part out, the thought experiment is really besides the point.
Then there is always the issue that Leif brings up…how does the fact that as temperatures drop ozone becomes more water soluble and how does this work up in the stratosphere? The process does not seem well described to me. Maybe Leif and myself are just both bothered by the way its described or what not, but I can not quite put my finger on why that description bothers me so much. The fact that there is so little water in any form in the stratosphere is probably what bothers me the most about the description.
erl happ says: August 21, 2011 at 10:07 am
I wonder if anyone has data on ozone in the Arctic troposphere over time?
Here’s one source;
http://www.temis.nl/
and this paper has several time series through 2005;
http://instaar.colorado.edu/arl/pdf/A_Review_of_Surface_Ozone.pdf
This paper is also pertinent to the discussion:
http://www.atmos-chem-phys-discuss.net/11/10721/2011/acpd-11-10721-2011.pdf
erl happ says:
August 21, 2011 at 10:07 am
I would suspect that the fall of temperature with altitude through the stratosphere would also assist.
Except that the temperature does fall with altitude through the stratosphere, not even during the polar night:
http://www.cpc.ncep.noaa.gov/products/stratosphere/polar/gif_files/time_p_t90s.png
From 20 km and up, the temperature increases.
There are interesting things going on, but they are not consequences of the scenarios you imagine. There is benefit to be close enough to reality that you capture the essential features and incorporate them in a ‘theory’. If you are not, the theory is not of interest.