Guest opinion: Dr. Tim Ball
A favorite exam question in my first-year climate class was, “Why is the North Pole warmer than the South Pole? I changed it each year, to confuse students who looked at last year’s exam; “Why is the South Pole colder than the North Pole?” Most people have no idea about the geography of the Poles and assume they are climatically the same. They are literally polar opposites and that is important in understanding the significance for global climate.
The major driving force for atmospheric circulation is the temperature difference between the Poles and the Equator – the gradient. Theoretically, maximum heating at the Equator and minimum at the Poles creates a single cell circulation system (Figure 1).
Figure 1
Rotation is the major perturbation to this theoretical base, followed by surface differences, particularly land/water ratios.
Earth’s elliptical orbit round the Sun is a small factor in determining the temperature difference. Two important points are perihelion, when the earth is closest, and aphelion when it is furthest away. (Figure 2)
Figure 2
The current situation is as follows.
The Earth is closest to the Sun or at its Perihelion two weeks after the December solstice and farthest from the Sun or Aphelion, two weeks after the June Solstice. In 2015, the Earth will reach its Aphelion at 19:41 (7:41 pm) UTC on July 6, 2015.
All this changes as part of the larger Milankovitch Effect, but it means that at present the Earth is closer during the Northern Hemisphere winter and further away during the Southern Hemisphere Winter.
At the risk of stirring up solar specialists, here is one estimate of the insolation difference.
Aphelion Insolation = [(149,597,870.7 km) / (152,098,232 km)] = 0.9674
Perihelion Insolation = [(149,597,870.7 km) / (147,098,290 km)] = 1.0343
It’s approximately a 6.5 percent variance, which is a minor difference but one amplified by other factors.
North Pole
Figure 3 shows that the North Pole is near the middle of the Arctic Ocean (approx. 16 million km2) almost totally surrounded by land that all lies within the Arctic Circle. It is essentially a flat plain at sea level.
Figure 3
The Arctic Ocean sits in an almost enclosed basin with only one deep channel in and out called the East Greenland Rift (Figure 4). (Soviet submarines used the channel during the Cold War). This means most water moving in or out of the Arctic Ocean is in the upper few hundred meters of the ocean. The Continental Shelf is vast and drops off to the deep ocean at 200 fathoms, instead of 100 fathoms like most others. The result is very large areas of relatively shallow water, visible as the light blue area in Figure 3 and the turquoise in Figure 4.
The essentially enclosed condition was a major part of the Ewing and Donn 1956 theory of the causes of Ice Ages. It led to alarmist headlines similar to those we see today, except it was The Coming Ice Age. (Is the author Betty Friedan of feminist fame?).
How a rising of the ocean waters may flood most of our port cities within the foreseeable future — and why it will be followed by the growth of a vast glacier which may eventually cover much of Europe and North America.
Albedo is high all year round because of the low angle of incidence. Reflected sunlight makes snow blindness a danger among people of the Arctic. They fashion snow goggles to combat the problem.
Note the very narrow slit.
Albedo changes significantly in the summer when some 10 million km2 of sea ice melts exposing low albedo, dark green, polar water.
Figure 4
This means that the influence of massive quantities of warm water on ice conditions are much more important. The other factor is the impact of the Polar Easterlies driving the sea ice in a constant rotation round the Pole. On Arctic survival with the Canadian Air Force, I learned that the winds were so consistent that the Inuit used the direction of snowdrifts for guides even under “white out” conditions.
Ice thickness was made an issue to add to the focus on sea ice melting. I wrote about the exploitation and misrepresentation of this in October 2012. Influx of warmer water is a major factor, as occurred in 1816. Another reason the North Pole is warmer than the South because of heat from this warm water moving through the ice to heat the atmosphere (Figure 5).
Figure 5.
Source: Climatology (Oliver and Hidore)
The biggest problem for climate research in the Arctic is the lack of data. Figure 6 shows that there is no data for most of the basin.
Figure 6
Source: Arctic Climate Impact Assessment (ACIA).
Polynyas are large areas of open water and a unique feature in the Arctic Oceans that contribute heat directly to the Arctic atmosphere. Figure 7 shows Polynyas for the Canadian sector of the Ocean.
Figure 7
The net result is the North Pole is cold, but nowhere near as cold as the South Pole. That is all we can say precisely because actual conditions at the geographic North Pole are not measured. Wikipedia says,
Winter (January) temperatures at the North Pole can range from about −43 °C (−45 °F) to −26 °C (−15 °F), perhaps averaging around −34 °C (−29 °F). Summer temperatures (June, July, and August) average around the freezing point (0 °C (32 °F)). The highest temperature yet recorded is 5 °C (41 °F),
Temperature is important because it determines the density of the atmosphere and, therefore, the height of the Troposphere, which affects the circulation.
South Pole
Little was known about the Antarctic continent until approximately 100 years ago, which is not surprising since the first confirmed landing occurred in 1895. Despite this, scientific interest triggered organization of an International Polar Year (IPY) in 1882-1883. The major advance in knowledge was the International Geophysical Year (IGY) in 1957, while scientific efforts to assess Antarctic climate began as recently as the third IPY in 2007.
Figure 8
The geography is directly opposite to the North with a continent surrounded by ocean (Figure 8). The entire area is above sea level with the South Pole at 2830 m (9,285 feet). The Tropopause is less than 8 km above Antarctica, so there is very limited atmosphere above the South Pole. The intensely cold air that drains down off the continent enhances the general circulation pattern of the Polar Easterlies. Known as a Katabatic flow, it generates remarkable winds. British Antarctic Survey reports
Port Martin (67°S 141°E) is an especially windy site with an annual mean wind speed of 17 ms-1 (33 kt — nearly gale force). The station has recorded a monthly mean wind speed of 28 ms-1 (54 kt — storm force 10) and a daily mean of 46 ms-1 (89 kt).
The Southern Ocean surrounds the continent and creates a dramatic contrast with the cold polar air. All these conditions combine to create a very powerful Circumpolar Vortex. Failure to understand or include these conditions was part of the misunderstanding and incorrect claim that CFCs were creating and enlarging the area of ozone thinning over Antarctica.
Figure 9 shows Polynyas (dark green) for the Antarctic for a specific day. They are defined as areas of thin ice or open water. Like the Arctic they are quite extensive. WUWT illustrated how Antarctic polynyas are primarily a result of katabatic winds. This was in response to a claim that they were going to disappear.
Figure 9
Sun angles are the same as in the Arctic, but the albedo is much higher because of the permanent snow and ice surfaces.
Net result of these differences means the North Pole is much warmer than the South. It is probably more accurate to say it is less cold. We only have an approximate difference because there are no instrumental readings for the North Pole. There are so few measures that application of the claim that a station represents everything in a 1200 km radius do not apply. Wikipedia says winter temperatures (January) range from -43°C to -26°C. South Pole records show winter temperature (July) range is from a mean daily minimum of -62.8°C to a mean daily high of -55.9°C. Regardless of specific accuracy, the difference is approximately 20°C difference, which is very significant in the fundamental driving force of atmospheric circulation.
Historically, this difference was amplified because a higher global mean temperature, such as during the Medieval Warm Period (MWP), had greater impact at the North Pole than the South. A 2°C change would have limited impact at the South Pole. It would have much greater impact at the North Pole altering conditions of the Arctic Basin including the sea ice, the snow line, the tree line, the albedo, and ocean circulation, among other conditions.
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As it warmed, sea ice declined from the 1950s –‘80s in Antarctica, before it began cooling again in the 1980s—in opposite phase to the Arctic.
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http://onlinelibrary.wiley.com/doi/10.1002/2014GL059821/abstract
We present the first proxy record of sea-ice area (SIA) in the Ross Sea, Antarctica, from a 130 year coastal ice-core record. High-resolution deuterium excess data show prevailing stable SIA from the 1880s until the 1950s, a 2–5% reduction from the mid-1950s to the early-1990s, and a 5% increase after 1993. Additional support for this reconstruction is derived from ice-core methanesulphonic acid concentrations and whaling records. While SIA has continued to decline around much of the West Antarctic coastline since the 1950s, concurrent with increasing air and ocean temperatures, the underlying trend is masked in the Ross Sea by a switch to positive SIA anomalies since the early-1990s. This increase is associated with a strengthening of southerly winds and the enhanced northward advection of sea ice.
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http://www.cgd.ucar.edu/staff/cdeser/docs/fan.antarctic_seaice_trends.grl14.pdf
This study compares the distribution of surface climate trends over the Southern Ocean in austral summer between 1979–2011 and 1950–1978, using a wide variety of data sets including uninterpolated gridded marine archives, land station data, reanalysis, and satellite products. Apart from the Antarctic Peninsula and adjacent regions, sea surface temperatures and surface air temperatures decreased during 1979–2011, consistent with the expansion of Antarctic sea ice. In contrast, the Southern Ocean and coastal Antarctica warmed during 1950–1978. Sea level pressure (SLP) and zonal wind trends provide additional evidence for a sign reversal between the two periods, with cooling (warming) accompanied by stronger (weaker) westerlies and lower (higher) SLP at polar latitudes in the early (late) period. Such physically consistent trends across a range of independently measured parameters provide robust evidence for multidecadal climate variability over the Southern Ocean and place the recent Antarctic sea ice trends into a broader context. ….. For the Southern Ocean as a whole, sea surface temperature has decreased by approximately 0.6°C in December-February (0.4°C in the annual mean) while Antarctic sea ice cover has increased by approximately 9% in December-February (12% in the annual mean) during 1979-2011.
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http://www.ipcc.ch/ipccreports/tar/wg2/index.php?idp=599
Another analysis of a 21-station data set from Antarctica by Comiso (1999) found a warming trend equivalent to 1.25°C per century for a 45-year record beginning in the 1950s but a slight cooling trend from 1979 to 1998. The slight cooling trend for this later 20-year period also was confirmed via analysis of surface temperatures over the whole continent, as inferred from satellite data.
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http://www.nature.com/nature/journal/v457/n7233/edsumm/e090226-02.html
Theoretical models and observational data have long suggested that the Northern and Southern Hemisphere climates behave in a seesaw-like fashion: when the northern ocean warms, the southern ocean cools and vice versa. So far, however, the data have indicated a much muted response in Antarctic climate compared to the Arctic. An analysis of new records from an ocean core from the South Atlantic — including planktonic foraminifera assemblages, Mg/Ca ratios, temperature and ocean productivity data — shows that the South Atlantic cooled essentially instantaneously with the warming in the North Atlantic during the last deglaciation. This first concrete evidence of an immediate seesaw connection also provides a link between the rapid warming in the North Atlantic and the more gradual Antarctic response, and suggests a mechanism potentially driving rapid Northern Hemisphere deglaciation.
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http://www.nature.com/nature/journal/v508/n7496/full/nature13076.html
An interhemispheric hydrologic seesaw—in which latitudinal migrations of the Intertropical Convergence Zone (ITCZ) produce simultaneous wetting (increased precipitation) in one hemisphere and drying in the other—has been discovered in some tropical and subtropical regions. For instance, Chinese and Brazilian subtropical speleothem (cave formations such as stalactites and stalagmites) records show opposite trends in time series of oxygen isotopes (a proxy for precipitation variability) at millennial to orbital timescales, suggesting that hydrologic cycles were antiphased in the northerly versus southerly subtropics. This tropical to subtropical hydrologic phenomenon is likely to be an initial and important climatic response to orbital [solar] forcing. The impacts of such an interhemispheric hydrologic seesaw on higher-latitude regions and the global climate system, however, are unknown. Here we show that the antiphasing seen in the tropical records is also present in both hemispheres of the mid-latitude western Pacific Ocean. Furthermore, our result implies that insolation [solar radiation]-driven ITCZ dynamics may provoke water vapour and vegetation feedbacks in northern mid-latitude regions and could have regulated global climate conditions throughout the late Quaternary ice age cycles.
Kepler’s 2nd Law applies to the speed of earth through its orbit, at perihelion it is at its fastest. What this means is that season will or should be shorter, especially compared to the same season at the opposite pole. I imagine the models take these things into consideration, at least I hope they do.
Thank you Dr. Ball informative as ever. Also Thank all of you for the open discussions that allow us everyday people a glimpse of how our climate really works. I am impressed by how facts are presented and debated here. This `atmosphere` lends to calm and frank exchanges. Well done.
Few people know that annual average absorbed radiation is almost exactly the same for the two hemispheres. This is in spite of the huge difference between their clear sky albedoes, the Southern hemisphere being inherently darker than the Northern one, due to prevalence of oceans there.
By the way, although at summer solstice the south pole gets more insolation indeed at ToA (Top of Atmosphere), annual averages are equal for the the two hemispheres because of a geometric peculiarity of Keplerian orbits.
Kepler’s second law says that “a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time”. Therefore the time needed for the planet to proceed by a small angle Δφ along its orbit (relative to the stars) is proportional to the square of its instantaneous distance from the Sun. As incoming solar flux is inversely proportional to the very same quantity, temporal integral of power flux at ToA is simply proportional to the angle travelled. Angular distance between the two equinoxes is 180°, so summer (or winter) insolation matches exactly at ToA for the two hemispheres.
That’s astronomy so far. To absorb an equal amount of energy in a year, average all sky albedoes of the two hemispheres should also match. That’s accomplished by clouds, to an astonishing degree. Under clear sky conditions the Southern hemisphere absorbs some 6 W/m² more energy than the Northern one, but once clouds (and snow) come into play, the difference is less than 0.1 W/m².
This remarkable symmetry is an emergent phenomenon, not replicated by current computational climate models at all.
To make it even more mysterious, there is no such symmetry in outgoing thermal infrared radiation, the Northern hemisphere’s heat loss to space being considerably higher. That implies an ongoing heat transport from the (colder) Southern hemisphere to the (warmer) Northern one, conceivably by ocean currents.
Journal of Climate, Volume 26, Issue 2 (January 2013)
doi: 10.1175/JCLI-D-12-00132.1
The Observed Hemispheric Symmetry in Reflected Shortwave Irradiance
Aiko Voigt, Bjorn Stevens, Jürgen Bader and Thorsten Mauritsen
For the record, I posted a comment about Kepler 23 minutes before you, but my comment is still in moderation. I will try posting a reworded version below in case my original gets lost in the Either.
garymount
Your comment is awaiting moderation.
February 14, 2015 at 2:58 am
Kepler’s second law applies to the speed of earth through its orbit, at perihelion it is at its fastest. What this means is that season will or should be shorter, especially compared to the same season at the opposite pole. I imagine the models take these things into consideration, at least I hope they do.
If you took the anomalies of the North and south pole temperatures and if the temperature of the south pole was less cold than it normally was and then measured the anomalies at the north pole as being more cold than it normally is then you could conclude that it was warmer at the south pole than it was at the north pole.anomalies distort our view of reality before we can think about reality.
Take Antarctica and make it 3 times bigger (same position over the south pole).
Okay, it is now attached to South America and it is closer to Africa. The Ocean currents are different in that the Antarctic Circumpolar Current cannot fully encircle the continent anymore but there is some type of circumpolar current on parts of the continent while the parts attached to South America set-up as Gyres which would bring warmer water in next to the continent at the portions attached to South America.
Now how big do the glaciers get?
I think they still cover almost all the land area. There are some non-glaciated regions next to the oceans, something like southern Greenland today, but the glaciers are 2.5 times bigger than they are today.
The extra Albedo from all that extra glacier will increase the Earth’s Albedo from 29.83% today to 30.70%. This will reduce the average Earth temperature from 15,0C to 14.0C, 1.0C colder.
That makes northern hemisphere ice ages much more likely as well. It might make northern hemisphere glaciation permanent but it is hard to tell. If it just tipped the balance to make northern hemisphere ice ages permanent, well then we are back to Snowball Earth, but probably not.
Just noting that the position and size of the continents along with the resulting ocean current alignments along with how much ice results from those impacts will change the overall planet’s Albedo and determine the climate that results.
Arctic Air Assault 15.02.
http://earth.nullschool.net/#2015/02/15/0300Z/wind/surface/level/overlay=temp/orthographic=-89.84,38.56,2086
Circulation in North America in the winter does not change much, but clearly decreased solar activity in this cycle. Arctic air descends further to the southeast. Polar vortex is shifted over Europe and does not block cold air over the Bering Strait.
I’m more persuaded by “scientific efforts to assess Antarctic climate began as recently as the third IPY in 2007.“, than I am of any claims or speculation about changes regarding the ice thickening or not thickening.
Tim
“Albedo is high all year round because of the low angle of incidence.
Albedo changes significantly in the summer when some 10 million km2 of sea ice melts exposing low albedo, dark green, polar water.”
These two statements do not gel for me.
In addition I do not understand the concept of low angle of incidence causing high albedo.
In my limited understanding the albedo is the amount of light that is reflected and this would have far more to do with the reflecting material [ice, water or land] than which way the light happens to land on the material in question.
“Sun angles are the same as in the Arctic, but the albedo is much higher because of the permanent snow and ice surfaces.”
I am sure an Eskimo could get snow blindness just as easily if transported to the South pole or if taken to a ski resort in Japan for a day. It is the reflection of light, not the angle of incidence.
“Wikipedia says winter temperatures (January) range from -43°C to -26°C.”
I know you mean the North Pole for these figures but best to add it into text to clear up the meaning of the paragraph.
South Pole records show winter temperature (July) range is from a mean daily minimum of -62.8°C to a mean daily high of -55.9°C.
wickedwenchfan said “In fact 20C difference is pretty standard for that kind of difference in altitude from sea level to 2800m!”
You said the North Pole is essentially a flat plain at sea level. both on the same wavelength I feel.
The reflectivity of water (and many other substances) depends very much on the angle of incidence. At normal incidence (the light hitting at a right angle) water will absorb nearly all solar radiation and reflect very little. At a ‘glancing angle’, it will act like a mirror, with a reflectivity close to unity.
http://upload.wikimedia.org/wikipedia/en/7/7f/Water_reflectivity.jpg
Good write up. I learned a few basics that I was unaware of. So it goes. Thanks Dr. Ball. Much appreciated.
Berényi Péter February 14, 2015 at 3:21 am Great post with Kepler but I do not understand some of your conclusions.
You said “, there is no such symmetry in outgoing thermal infrared radiation, the Northern hemisphere’s heat loss to space being considerably higher. That implies an ongoing heat transport from the (colder) Southern hemisphere to the (warmer) Northern one, conceivably by ocean currents.”
but your reference Journal of Climate, Volume 26, Issue 2 (January 2013) contradicts this in its heading
“The Observed Hemispheric Symmetry in Reflected Shortwave Irradiance”
It is also contrary to the concept of black body radiation which implies heat in equals [mainly infra red] heat out.
If the Northern Hemisphere is indeed putting out a higher amount of infra red to space, the simplest concept would be that it is taking more in to send back out. The simplest way for this to happen would be despite the higher implied NH albedo there are less clouds and the NH in fact has more heat coming in [actual lower albedo].
Not needing “ongoing heat transport from the (colder) Southern hemisphere to the (warmer) Northern one, conceivably by ocean currents.” which again violates thermodynamics generally in that heat does not move from colder to warmer areas.
“Few people know that annual average absorbed radiation is almost exactly the same for the two hemispheres”.
Not surprising once you accept your explanation that in effect they have the same overall albedo.
Was not aware that although ” at summer solstice the south pole gets more insolation indeed at ToA (Top of Atmosphere), annual averages are equal for the the two hemispheres because of a geometric peculiarity of Keplerian orbits
Lost on this one, I feel you are choosing a Keplerian orbit of a rotating planet with a fixed plane of inclination. Once it wobbles a bit, which the earth does, and sticks the Southern hemisphere closer to the sun at it’s hottest, which it does, then I am not sure that there will be an equal annual average for the two hemispheres but maybe the astronomers here can help.
One of Keller’s laws simply states that an equal area is swept out for an equal time. That means that in an elliptical orbit, the farther away, the slower the orbit.
http://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion#Second_law
Read Voigt &. al. 2013 carefully. Based on CERES-EBAF they conclude reflected shortwave radiation is indeed the same for the two hemispheres (see TABLE 1. on page 469). As incident shortwave is also the same, absorbed shortwave radiation should match as well. That means the Northern hemisphere is not “taking more in to send back out”. It can only radiate more thermal infrared out, because there is some 700 TW net heat transport northward across the equator.
The astronomical part is uncontroversial, it even holds for elongated elliptical orbits with any tilt of the planetary equator relative to the plane of its orbit. I believe it is taken into account in computational climate models, because both the physics and math are simple behind it.
On the other hand, the inter-hemispheric symmetry of all sky albedo depends on clouds, which are poorly represented in computational climate models, because all the relevant processes driving cloud formation work on scales well below their grid size. That means modelled clouds are driven more by prejudices and guesswork than by physics.
A word of caution regarding the relation between absorbed shortwave and emitted longwave radiation in CERES-EBAF is appropriate here. Their global difference (a.k.a. planetary imbalance) is not measured by satellites, the end product is adjusted in this respect using ARGO OHC (Ocean Heat Content) measurements.
That’s because there is a completely unphysical mismatch between satellite measured shortwave input and long wave output on the order of several watts per square meter. It means CERES data may be precise, but they are not accurate enough to estimate the value of imbalance.
Fortunately we are not interested in difference between incoming and outgoing fluxes here, but we can compare apples to apples and oranges to oranges.
It would be interesting to repeat their study using CERES-EBAF 2.8 (March 2000 – October 2014). Voigt &. al. only had version 2.6 (March 2000 – February 2010). That is, we have data for 56 more months now, 176 months instead of 120.
I find the Voigt 2013 paper fascinating from several perspectives. Their Fig 2. show the 2 subtropical gyres reflect the least SW suggesting those are the centers of greatest heat accumulation. Subtropical gyres underlie the high pressure systems that are drier, with more clear sky. Those heating centers are also more cloud free during La NIna conditions, as well as warm periods like the Medieval Warm Period.
There is indeed net cross-equatorial heat transport in the Atlantic but not the Pacific. But I doubt that fully explains the greater outgoing infrared in the NH. Most of the cross-equatorial ocean heat is stored below the surface and has minimal effect on surface heat flux (Donahue(2014). Indeed Heimbach and Wunsch show the mid Atlantic stores a tremendous amount of subsurface heat.
However increased westerlies during a positive NAO help ventilate that heat. Also the transport of heat deep into the Arctic enhances cooling. Warm intruding Atlantic waters are upwelled on to the shallow coastal shelves and vented to the atmosphere though expanded polynya. Indeed the simultaneous cooling of the upper 700 m of Arctic waters and the warming air is consistent with that heat ventilating scenario.
In contrast water warmed in the SH hemisphere is deflected by the Circumpolar Current and then pumped equator-ward. Polar ventilation is minimal. Growing regional Antarctic sea ice is consistent with cooler sea surface temperatures, and thus less outgoing LW.
Does Voigt or others have a diagram of the spatial patterns for outgoing LW anomalies to illustrate the regional patterns that drive the outgoing LW asymmetry?
B Peter:
Concerning the discrepancy between incident SW radiation and outgoing LW radiation, as measured, how much of that discrepancy is due to the absorption of SW radiation by photosynthesis, I wonder? I would imagine that photosynthesis would account for much or perhaps all of it.
“Not needing “ongoing heat transport from the (colder) Southern hemisphere to the (warmer) Northern one, conceivably by ocean currents.” which again violates thermodynamics generally in that heat does not move from colder to warmer areas.”
////////////////////////////
But you are overlooking that there is a heat pump.
Is it not the position that Energy absorbed in the Southern Hemisphere oceans rather than warming those oceans and thence being radiated therefrom and thereby contributing towards the radiation emitted from the Southern Hemisphere, is instead carried northwards (both by ocean currents and by air currents) where it goes to warm the Northern Hemisphere more than the Northern hemisphere would otherwise be warmed by such solar energy that finds its way to the surface (ie., making its way through clioudy skies)? This means that some of the energy received in the Southern Hemisphere is radiated not from the Southern Hemisphere but from the Northern Hemisphere, and hence the reason why the Northern Hemisphere radiates more than would otherwise be expected.
Correct. Ocean circulation is not a heat engine, it is not driven by temperature or salinity differences, but by pure mechanical energy input provided by tidal breaking and winds.
Therefore thermohaline circulation is a misnomer, it is valid only for the downwellingbranch. Upwelling, on the other hand, is an entirely different matter. Although it is necessary to close the circuit, dense &. cold bottom water would never rise to the surface on its own, driven by thermodynamic forces, to replace lighter &. warmer water parcels there. So with no low entropy mechanical energy input, the abyss would eventually get saturated with cold &. salty water and at that point the circulation would grind to a halt.
Heat conductivity of water is very low and diffusivity of salts in seawater is even lower by some 2 orders of magnitude. Therefore these processes are insufficient to resupply buoyancy to the abyss. Geothermal heat flux could keep up some very slow overturning, because in this case heating happens at the bottom, in a gravitational well compared to location of cooling, but it is only powerful enough to drive a circulation several orders of magnitude weaker than what is observed.
In the strict sense of the word there is not even such a thing as “upwelling”. What happens instead is deep turbulent mixing. That is, less dense surface waters get mixed with cold &. dense deep waters, providing the necessary buoyancy at depth to keep up circulation.
However, in most of the open ocean even vertical turbulent mixing is measured to be insufficient to do the job. It is only at specific sites, intermittently, that rate of deep turbulent mixing increases by several orders of magnitude, due to breaking of internal waves over rugged bottom features and at continental margins of complex geometry. Internal waves themselves are generated by lunisolar tides and downward transfer of wind energy mediated by surface waves. About 80% of wind forcing occurs over mid latitude Southern oceans (roaring forties, furious fifties) and I believe that’s what makes the difference.
Perhaps it is not even necessary to mention, that no computational climate model gets deep turbulent mixing right, mostly because it is another sub-grid process.
B Peter:
Are you familiar with the Eckman Effect, also known as the Eckman Pump?
I see that in the UK the Lib, Lab, Con leaders have made a pact to make legislation to avert Climate Change by for example banning coal fired power stations.
I have only been reading this blog for a few weeks but it seems clear to me that the man made Global Warming/climate change is more than likely a load of old bollocks put about by pseudo science encouraged by vested interest.
I can understand a grant-seeking researcher exaggerating the importance of their work but I would have thought that HMGov employed expert advice to advise it of the truth of a matter and I would expect then that a British Politician would act in the best interests of the Country.
Unfortunately, human nature is usually governed by self interest. It is hard to think of an example where a politician has acted in the best interests of the country.
In general I expect politicians to put their own interests first, their constituents’ interests second, and their nation’s interests third. Sometimes two or all of these interests coincide, but often they don’t. Note that politicians, being fallible humans, also misidentify these interests on occasion.
Zemlik – HMGov only employs experts in ‘climate science’, all of whom have vested (financial and reputational) interests in keeping that loob alive. For confirmation just look at the composition of the Committee on Climate Change.
As a student I would use the KISS principle.
The continent under Antarctica allows for two km of ice buildup. Not so the north pole. The temperature at that height is 20 C colder.
The rest is over egging.
Thank you Dr. Ball for a clear and understandable discussion on a subject that is inadequately covered. Posts like yours which stay away from sometimes politically charged verbiage also bring out the best in commenters and is a primary reason why WUWT is my go-to source for facts and information.
The difference in temperatures between the two poles well illustrates the principle that oceans have a profound effect on climate, and of course means ocean circulation.
The land mass of Antarctica assures the thermal isolation of this pole because oceanic influences are kept at vast distances from the geographic pole, while, in the Arctic, waters circulate tropical heat transported there by the Gulf Stream. As Dr. Ball points out, this means a much colder South Pole and explains why so much ice is locked up in that continent (over 90% of the world’s ice).
Excellent post Dr. Ball.
Just like to add a thought to readers here who may not realize the actual size of Antarctica.
From Wikipedia:
Antarctica – 5.4 million square miles
Europe – 3.3 million square miles
USA contiguous states – 2.96 million square miles
Antarctica is much larger than it looks on a world map as well as elevation at its surface.
eyesonu
For consistency, let’s put those in metric units, then compare them to areas you “see’ on the standard climate scientist’s Mercator projection map. Which cuts off all of Antarctic anyway.
Ooops.
Just the “excess” Antarctic sea ice last June was as large as ALL of Greenland.
Comparable to ALL of Alaska.
Bigger than ALL of Western Europe above the Arctic Circle.
At sea ice minimum, the Antarctic ice covers twice the size of Australia.
Antarctica at minimum sea ice is larger than all of South America’s part of the Southern Hemisphere.
Antarctica at maximum sea ice is the largest area in the ENTIRE Southern Hemisphere! (Bigger than sub-Sahara Africa and South America combined!).
To illustrate what is NOT covered in Hansen’s Mercator map projection.
At sea ice maximum, Antarctic’s total ice covers everything from latitude 59 south all the way to the South Pole.
Now, draw a line at latitude 60 north, then cover everything from that line all the way to the top of your map. (Hint: Start just a little below the southern tip of Greenland.) Get your white out (or a bucket of paint) and paint all of that area “white” …. That area you just painted is the Antarctic sea ice and land land ice.
RA,
Good comments – Thanks for putting it all in perspective!
Mac
Thanks for that. I never realized just how large a region it is down there.
When I look at the world maps on my wall, Antarctica only shows up as pieces. When I look at a globe it is not easily seen. Maybe they should start mounting globes upside down. 🙂
Thanks for an interesting comment.
You are claiming that Hansen and other climate scientists use a Mercator projection, which exaggerates the size of Antarctica and Greenland compared with the rest of the world. Like Tim Ball you need to read up on map projections. The papers by Hansen appear to show Equirectangular projections, not Mercator, which still exaggerates the Arctic and Antarctic, just not as much.
GISS maps are Robinson projections which still exaggerates near the poles:
http://www.giss.nasa.gov/research/news/20150116/2014_annual_w-colorbar.png
True. I did write that they use a Mercator Projection. They are exaggerating the Arctic [area] (deliberately), and removing the Antarctic area (deliberately) because each practice further promotes their agenda, and the Big Government control they are paid and promoted to produce by their positions within Big Government. Until the small size of their massive “red splashed extrapolations” across the the intermediate wastelands of the tiny Arctic areas of Greenland and the Arctic Ocean are corrected, the very small differences (on unlabeled plots with no latitude lines – which will be poorly understood if seen at all by 97% of their intended victims (er, viewers) – in their equirectangular projections are properly ignored.
Besides, if “illustrating” a projection to the greater public, what is the training value when the audience needs 15 minutes of explanation about how “a equirectangular projection is less but not quite as bad as a Mercator projection” when the public (if they have heard of ANY projection at all!) only has a passing knowledge of Mercator in the first place?
So, it is more accurate to say “Just the “excess” sea ice around the Antarctic last June covered an area the size of Greenland. All of the Antarctic ice in September covers an area larger than Africa and South America. Combined.”
For consistency, let’s put those in metric units, then compare them to areas you “see’ on the standard climate scientist’s Mercator projection map. Which cuts off all of Antarctic anyway.
As shown they do not use a Mercator and do not cut off the Antarctic.
They are exaggerating the Arctic (deliberately), because that further promotes their agenda, and the Big Government control they are paid and promoted to produce by their positions within Big Government. Until the small size of their massive “red splashed extrapolations” across the the intermediate wastelands of the tiny Arctic areas of Greenland and the Arctic Ocean are corrected, the very small differences (on unlabeled plots with no latitude lines – which will be poorly understood if seen at all by 97% of their intended victims (er, viewers) – in their equirectangular projections are properly ignored.
If they are exaggerating the Arctic they are also exaggerating the Antarctic. The maps I see in Hansen’s paper are annotated. If they really wanted to exaggerate the Arctic then surely they would use the Mercator instead of the more accurate projections.
You were apparently claiming that Antarctica was larger than it appeared on world maps whereas the opposite is the case, now you are changing your tune! The ‘tiny’ Arctic ocean is a greater area than the USA by the way.
So, it is more accurate to say “Just the “excess” sea ice around the Antarctic last June covered an area the size of Greenland.
Now the ‘total’ Antarctic sea ice is about the area of Greenland.
False. The released maps and red-splotched areas do eliminate the Antarctic.
You are nit-picking the lice in your opponent’s eye, and ignoring the log in your own.
Press releases and political statements ALWAYS emphasize the “loss of arctic sea ice” and ignore the 22 year-long increase in Antarctic sea ice across all seasons of the year and across all latitudes. When the 22-year long Antarctic sea ice increase is mentioned, and it has every now and then, it is described as “small” or insignificant or trivial or less than 1%. Instead, the Antarctic sea ice anomaly is 35% above normal at minimum, and 15% to 25% above normal at maximum. Hardly trivial.
Arctic sea ice extents have been within 2 std deviations of an assumed 1979-2008 “normal” for the past 2 years. Not out of natural variation by that definition. Antarctic sea ice has been steadily ABOVE 2 std deviations of the same “normal” for almost all of the past 24 months – again, well above “natural variation”!
Blamed on a change in winds or air temperatures due to “global warming” ?
No, neither claim stands up against measurements – or the lack thereof.
False. You are both taking words out of context, and missing the conclusions in the words, and forcing the result of your biases and your assumptions on those words.
The tiny Arctic Ocean is tiny. At 14.0 Mkm^2, it is less than the area between +2 degree north latitude to -2 degree south latitude (17.8 Mkm^2.) that tiny Arctic area is irradiated by sunlight strongly 3 months of theyear, but hides below the horizon, or through 6 to 13 air masses the remaining 9 months of the year. In the earth’s heat balance, the Arctic IS “tiny.”
But the “vanishing” Arctic sea ice” is just about the only thing saving the CAGW theory today, so it must be propagated. Propagandized.
Nine months of the year, the sunlight falling on the Antarctic sea ice as it oscillates between 68 soth latitude and 58 south latitude contributes more to the earth’s energy balance than that falling on the Arctic sea ice – trapped in its narrow band between 71 north latitude and 90 north.
Your words are wrong, thus your conclusion is wrong.
The Antarctic land ice is a constant 14.0 Mkm^2 – as large as the Arctic Ocean at its maximum. That Antarctic land ice is surrounded by 1.5 Mkm^2 of permanent Antarctic shelf ice.
Those two areas are surrounded by the Antarctic sea ice as IT varies between a new minimum of 2.5 Mkm^2 and a many-year ever-higher average maximum of 15.5 to 16.0 Mkm^2.
Thus, the TOTAL Antarctic ice – which are the words I use when total area matters! – is larger than the combined southern hemisphere land areas of South America and sub-Saharan Africa combined. You incorrectly attempt to claim only 2.5 million sq kilometers of Antarctic ice exists. No.
Today, even as it nears minimum extents, 18 million sq kilometers of ice are available to reflect sunlight down south. The edge of that sea ice is not at 85 north (1.0 Mkm62 of Arctic sea ice), nor 83 north (2.0 Mkm^2 of Arctic sea ice) nor 81 north (the recent record low Arctic sea ice in Sept 2012). The edge of the Antarctic sea ice is instead near the Antarctic circle at 67 south. 1/3 up the midpoint of Greenland.
But, the maps published (propagandized) by the CAGW community cut off Antarctica at the base of the peninsula, rarely displaying anything south of the Antarctic circle at all. And, if the Antarctic is displayed at all, the sea ice around Antarctica (a band starting at mid-Canada or middle Europe at maximum and extending all the way to the pole) is shown as “blue ocean” …)
Phil.
I was correct in my statement: Last June, the record-breaking “excess” Antarctic sea ice (the Antarctic sea ice anomaly was 2.06 Mkm^2) was the size of Greenland (2.16 Mkm^2.) Today, the Antarctic sea ice anomaly is “only” = 0.501 ; the Antarctic sea ice area = 2.513. So it is “only” 25% above normal.
But, the maps published (propagandized) by the CAGW community cut off Antarctica at the base of the peninsula, rarely displaying anything south of the Antarctic circle at all. And, if the Antarctic is displayed at all, the sea ice around Antarctica (a band starting at mid-Canada or middle Europe at maximum and extending all the way to the pole) is shown as “blue ocean” …)
As shown above this is not true for GISS nor was it true of Hansen’s 1988 paper (the one scientist you actually named), so how about you give some specific examples rather than false generalizations?
http://www.giss.nasa.gov/research/news/20150116/2014_annual_w-colorbar.png
So, at “maximum sea ice,” Antarctica is the size of Canada, US, Central America, and South America. Roughly.
The Antarctic is roughly 20 deg C colder than the Arctic. The former is at 2.83 km elevation, the latter at sea level. The atmospheric lapse rate averages 6.4 deg C per km. So 6.4 x 2.83 = 18.1, which explains almost entirely the difference in temperature between the two poles, no?
Thank you, Dr. Ball. This was one of the few science articles that even someone like myself could understand (a lowly computer programmer – business applications, not modeling). I wish I had more professors like yourself when I was in college many years back – you have the rare ability to make complicated subjects understandable.
Thanks Dr Ball, another fine post.
However to my perspective the major difference is the geography.A frozen continent surround by ocean, versus a shallow sea surrounded by land .
The transport of heat north continues year around via the river systems.
The Mackenzie River here in the Northwest Territories never stops moving water even in the coldest winters, ditto the rest of northern flowing watershed.
In the canadian spring the impact of waters warmed on southern land is obvious to all.
Lake ice, sea ice is eroded before any observers eyes.
At summers end, the north starts to freeze while the south stays warm, so these rivers are always the last to ice over and their ice is treacherous.
Seems to me the combined arctic watersheds move a very substantial amount of heat into the arctic ocean.
“It’s approximately a 6.5 percent variance, which is a minor difference but one amplified by other factors.”
Not really.
Although the calculations we see are for full Earth coverage, at any given time the Earth has twice the used rates, i.e. not the average annual rate of 341.5 W/m2 but 683 W/m2. This 6.5% difference is 44.5 W/m2. So between aphelion and perihelion there is a (maximum) 44.5 W/m2 difference in the solar insolation going to the southern hemisphere. Since the maximum insolation also hits the Antarctic during its “summer”, the difference in solar input for Antarctica is very significant – especially since the IPCC has equated the CO2 forcing for a doubling value to 3.5 W/m2 as a whole Earth, or 7.0 W/m2 equivalent for the half-Earth under illumination.
And yet the Arctic is, on average, 2C warmer than the Antarctic.
The reversed situation of insolation and average temperature tells you that the Earth is a gigantic heat redistribution (or solar energy) machine adept at ignoring simply physics. Any slight modification in the current system will result in noticeable changes elsewhere. It is only by assuming that the climate system is stable to fifteen parts in a million can you expect stability of the eco-green, IPCC narrative.
Regional differences are huge and not obvious in their causes. We backtrack from observations to causes that seem reasonable and are sufficient to explain the current phenomena – but not even the recent past as in the 1940 to 1960 cooling. The CO2-is-the-devil curse is built on the myth of climate stability (in the 60-year time-frame).
The bogeyman in the climate wars is the nervous Nellie looking for simple answers and certainty in a complex and uncertain world.
Hello Tim.
Sorry for been critical at this point, but from my perspective in the climate issue, your article above is the very meaning and explanation of the point that AGW and man’s influence in climate was not a hoax, at least from the point THAT it started at, and also the claim that most of concerned in climate and climate change belong to the 97% consensus of AGW.
Your article above is the very proof of the cardinal mistake of the AGW.
If you ever pretend that Hansens and Phil Jones of this world are inferior to you in their approach and understanding of climate, then you should reconsider.
While decades ago these guys had any right to approach the issue the way they did, you could not afford it at this time, in the 2015 .
You see, whatever you may claim about your point in science, even while considering the basic approach for a starting point to further expand the knowledge, when it comes to albedo effect in climate, is already proved that is meaningless in the climate and climate change.
You are at the very point that Hansen and Phil were decades ago, and I am really sorry that you can’t see that.
And these other guys you may disagree with were in a far much better position that you are today.
Hopefully I am wrong, but the way I see it is that without the albedo effect there is no basis of AGW, as the thing stands, and Hansen and Phil were at it long before you, and they seem to be in a very paradoxical possition.
Thank you
cheers
Would you like to rewrite that in intelligible English!
Catastrophic Global Warming has nothing directly to do with albedo, the hypothesis is about the role of CO2 in driving climate change. Please find me one example where a recorded change of climate has been caused by CO2. Oh and which 97% are you taking about ?
Hello Peter Forster.
Is really a pain to go through again and again with this bull sh..t when people try to argue about things they have no clue about.
I don’t know how much you have heard about Runaway Global Warming, but that is the initial claim of AGW, and had a lot for not saying it was totally based on albedo, then where Hansens and Phils started at with AGW.
WE HAVE COME A LONG WAY SINCE THEN BUT NEVER THE LESS THAT PROVED THAT ALBEDO IS NOT THE LANGUAGE OF CLIMATE, ATMOSPHERE OR THE EARTH SYSTEM, AND WHETHER YOU UNDERSTAND OR NOT MY ENGLISH THAT IS NOT THE POINT, THE POINT IS THAT WE HAVE NO CLUE YET AT WHAT LANGUAGE CLIMATE, ATMOSPHERE AND EARTH SYSTEM IS SHOUTING AT US, AS WE TOO OBSESSED WITH THE ALBEDO LANGUAGE.
Hope this clarifies the matter for you.
Thanks for the interest, please do not hesitate to ask for further explanation if you still not clear.
cheers
Oh, and when regarding the 97%, is the 97% consensus in the AGW, the one you definitely belong to, regardless if you accept or realise it or not.
Whether Catastrophic or Benign AGW is still AGW.
AND THAT WHAT THE 97% CONSENSUS IS ABOUT, the consensus about the AGW..
Sorry for saying that, but no other way to put it.
cheers
Dr. Ball, thanks for the comment on the so-called ozone hole, which is simply an annual, seasonal cycle in the balance between natural ozone creation and natural ozone destruction. On the creation side, solar UV is required to create and replenish the naturally diminishing ozone, but in the winter, the poles are dark and no UV hits the atmosphere. It really is no more complicated than that. When the sun rises over the Arctic and Antarctic circles in spring, ozone begins to be created again, and the “hole” gradually disappears. Anyone who claims to know that the ozone hole is man made, or that it’s a climatic harbinger, or that it is somehow a tragedy for human beings, animals, or anything, is experiencing an internal ID-10-T error code.
Just a couple articles found quickly at Dr. Ball’s web page
http://drtimball.com/2014/un-global-warming-propaganda-campaign-return-to-perceived-success-indicates-desperation/
http://drtimball.com/2011/holes-in-the-recent-arctic-ozone-hole-story/
You have this completely backwards, the ozone hole forms in the spring due to the return of the UV light which causes the depletion photochemical reactions to start.
Phil, my understanding is that the “record” ozone hole (although it’s not much of a record, given the duration of our measurements) over the Antarctic came early in September, 2006, which is in late winter, several weeks ahead of the SH spring equinox. I believe that the “hole’s” dimensions peak annually around this time. I ran two plots on NASA’s Giovanni web site for this February 14, 2015 and Sept 14th, 2014, and it shows the total ozone column over the Antarctic vastly lower in the Sept plot. Do you know differently? How? Can you give a reference?
Here are the links, I don’t know if this site reconstructs from the URL or not.
September 14, 2014:
http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/results.cgi?wsid=14241071778940&app=latlonplot&instance_id=omi&sid=142410693626169&gsid=omi_50.154.247.157_1424106936&selectedMap=Blue%20Marble
Feb 14, 2015
http://gdata1.sci.gsfc.nasa.gov/daac-bin/G3/results.cgi?wsid=14241070762908&app=latlonplot&instance_id=omi&sid=142410693626169&gsid=omi_50.154.247.157_1424106936&selectedMap=Blue%20Marble
The NASA Giovanni links above do NOT work. Sorry. I didn’t know if the URL stored enough data to reconstruct the plot. Use the root URL and then just select total column ozone from the generation software for those two dates to see the images.
The largest extent of the ozone hole was 24th September 2006 at 29.6 million Km^2, the minimum O3 concentration that year was 8th October.
http://ozonewatch.gsfc.nasa.gov/meteorology/annual_data.html
It’s a springtime event caused by the ozone depleting species being released as the PSCs sublime and the photochemical reactions being initiated by the return of UV light.
Great post.
In reply to:
John Niclasen February 14, 2015 at 12:21 am
Good overview, Tim! And then there is the additional feature, the Bipolar Seesaw:
http://en.wikipedia.org/wiki/Polar_see-saw
The video presentation linked to in Niclasen’s comment contains and helps to perpetuated three urban myths.
Urban Myth 1: ‘Polar See-Saw’ Should be called ‘Greenland/Antarctic Ice Sheet cyclic temperature Anomaly’
It is common in science to use an incorrect, vague, misleading label for a phenomena which confuses the facts concerning the phenomena and makes it difficult if not impossible to solve the puzzle of what is causing the phenomena in question.
It is common in science for urban myths to be passed on from teacher to students and to the public. The climate wars are part of the reason why these urban myths are perpetuated and promoted.
It is a fact that the planet cyclically warms and cools (both hemispheres) correlating with cyclic changes to the sun.
When the planet cyclically warms (both hemisphere) the Antarctic ice sheet slightly cools and when the planet cyclically cools the Antarctic ice sheet slightly warms. The Antarctic ice sheet polar vortex isolates the Antarctic ice sheet from temperature changes in the Southern ocean. The Antarctic peninsula extends outside of the polar vortex. Ice core samples from the Antarctic peninsula show cyclic warming and cooling that matches the cyclic warming and cooling that occurs in the Northern hemisphere.
The Southern hemisphere as a whole warms when the Northern hemisphere cools and vice versa. It is only the Antarctic ice sheet that slightly cools when the planet as a whole cyclically warms and slightly warms when the planet slightly cools.
The second urban myth is that ocean currents mysteriously change to cause the ‘polar see-saw”. The third urban myth is that the earth’s climate system and mysteriously jump from one state to another with no significant forcing change. (I will address the other two urban myths in separate comments.)
Temperature on the two ice sheets, Greenland and Antarctic can be directly determined by in situ temperature measure of the ice sheet using thermometers (RTDs) that are buried in the ice at different depths and then insulating the hole from ambient temperature. When equilibrium is reached the buried thermometers provide a method to determine past temperatures on the ice sheets for roughly 10,000 years.
The borehole temperatures data (Greenland and Antarctic ice sheets) indicate there is no time delay for the Antarctic temperature anomaly. This observational fact and the fact that it is only the Antarctic ice that is slightly cooling when the both hemisphere are warming and vice versa completely rules out the possibility that ocean current changes are causing the Antarctic ice cyclic temperature sheet anomaly. (i.e. It is physically impossible for the ocean current changes to cause what is observed. The assertion that ocean current changes are causing the cyclic change is an urban myth. Completely incorrect.
The planet is cyclically warming and cooling due to solar changes that modulate the amount of planetary cloud at high latitudes. The albedo of the Antarctic ice sheet is slightly higher than clouds. An increase in cloud cover and the fact that Antarctic ice sheet is isolated from the Southern ocean temperature changes due to Antarctic polar vortex explains why the Antarctic cyclic temperature anomaly occurs.
http://arxiv.org/abs/physics/0612145v1
“Influx of warmer water is a major factor, as occurred in 1816.”
The Polar see-saw in action. The Sun weakened from 1995 and the same has occurred. There seems to be a general consensus that the Arctic temperatures generally follow global temperatures, which then necessitates a sophism to explain the polar see-saw effect.
What has confused everyone is the warm spike in the GISP ice core proxy around 1000 AD. Regional proxies show Europe as warm or warmer than recently in the 8th century when GISP was cold. The evidence for cooling in the mid latitudes and increased El Nino induced drought in the late 10th and early 11th centuries is there. The same for the misnomer of the so called “Minoan Warm Period” in GISP around 1200 BC.