[John Mason]

I'm a bit sceptical about it in the link above, but it's worth noting that the second author on the Liu et al paper, Judith Curry, has a reputation as being very sceptical.

Cheers - John

[ldavidcooke]

Hey Sam,

Initially I was concerned as well. It just seemed convenient, that they were taking in a change and passing it off as evidence. However, they are only partially telling the story which is why it seems inplausable. First we are told that AGW is caused by increased CO2 in the atmosphere and the loss of radiational cooling will cook the planet. Next they say the polar ice is melting because the total global temperature is rising. In truth they are correct that a loss of radiational cooling will change the weather patterns, the problem is they got the cause and effect wrong...

Clearly it is getting warmer near the poles. By the same token it is getting warmer globally, the problem is they appear to have the mechanics wrong. It is interesting to suggest CO2 radiational cooling is causing the increase in the GAT. However, when we add in advection and review the ridge/trough pattern of the polar jet streams it becomes clear most of the Equatorial-Temperate zone warmth is moving poleward and should be radiating out near there.

This also brings us back to the loss of radiational cooling. Is this true, apparently, to a degree, the biggest change though is the difference in radiational acceptance or optical depth across the solar insolation band (TSI). Looking at the daily temperature record the difference between the low and high temperatures are increasing roughly up 5 degrees on average due to a reduction in specific humidity or put another way the water vapor optical depth is increasing as is the UV from a reduction of 30-50% of Ozone in the Stratosphere.

The added radiational energy is contributing to the radiational band saturation, hence contributing to the loss in radiational efficiency. To attempt to reduce the temperature imbalance between the Temperate and Polar zones advection has increased which is causing both ocean SSTs and High Altitude tropospheric temperatures to rapidly rise at the poles. The result, due in part to the difference in area is a doubling of the increase in equatorial temperature rise (roughly 2.7 deg. F to an average 5.5 deg. F), moving to the poles. The result is similar to the AGW hypothesis, just the mechanics are a bit different. (It still amazes me that it seems specialists cannot seem to see the forest for the trees.)

(I am not a scientist nor have I absolute proof of cause and effect; however, this description seems the most logical and takes what appears to be conflicting evidence and demonstrates how it is not conflicting. Instead it points to a different hypothesis then AGW being the sole cause and can be tested without the need of extensive parametric manipulation... Though I concede I could be wrong and not being a expert, my ramblings could be offensive to those who are; however,... )

[ldavidcooke]

Hey Sam,

Just to offer an example of the change in radiational cooling vs advection. Currently it is pre-dawn and the outside temperature is a "balmy" 55 F, the humidity is @ 60% and the clr skies are beginning to cloud up. Last evening at 1700 local EDT it was a wonderful 82F and 35% humidity and clr skies. By 2300 it was 62 F and 50% humidity and still clr.

In short, over 7 hours the majority of the solar gain of the day was released and the ground temperature achieved what was approximately the air temperature at 300 meters. The remaining change in temperature or drop of 7 deg. was the advection as the last of the warmer water vapor was replaced by the downdraft of an approaching' moisture laden front, meaning air falling from a cooler height was washing out the last of the warmth of the day, else the temperature would have dropped a other 5-10 deg.

The point, under clear sky conditions, the temperature would have dropped more then 30-35 deg. This in a region of the country that ranges no more then a 30 deg. drop in the Spring/Fall low water vapor content night sky.

The change is likely due to warmer temperatures aloft reducing specific humidity/radiational buffering. This should lead to higher radiational cooling, not less and result in lower then normal surface temperatures. (Especially when we suggest that the GAT is @ 65% due to wv content.)

So why is the local temperature 82F rather then the normal 62F by day and 55F rather then the normal 35F by night? Simple, it is due to the adiabatic warming of the falling air from the overhead High pressure. It is a change in this alone which appears to result in a higher surface temperatures and not radiational emission reduction. It is this temperature differential which is working poleward and contributing to tne Polar ice loss, IMHO.

[Dave K]

A new paper on this, which is available with open access:


Cold winter extremes in northern continents linked to Arctic sea ice loss
Qiuhong Tang, Xuejun Zhang, Xiaohua Yang and Jennifer A Francis
Issue 1 (March 2013)

Quote

The satellite record since 1979 shows downward trends in Arctic sea ice extent in all months, which are smallest in winter and largest in September. Previous studies have linked changes in winter atmospheric circulation, anomalously cold extremes and large snowfalls in mid-latitudes to rapid decline of Arctic sea ice in the preceding autumn. Using observational analyses, we show that the winter atmospheric circulation change and cold extremes are also associated with winter sea ice reduction through an apparently distinct mechanism from those related to autumn sea ice loss. Associated with winter sea ice reduction, a high-pressure anomaly prevails over the subarctic, which in part results from fewer cyclones owing to a weakened gradient in sea surface temperature and lower baroclinicity over sparse sea ice. The results suggest that the winter atmospheric circulation at high northern latitudes associated with Arctic sea ice loss, especially in the winter, favors the occurrence of cold winter extremes at middle latitudes of the northern continents.

http://iopscience.io..._8_1_014036.pdf

[ldavidcooke]

Hey Dave,

They have most of the observations correct. I suspect the conclusion though.

A reduction in Sea Ice is not a cause, it is an effect. Like a web search Tag, the loss of Sea Ice actually is indicating a large outflow of the Gobal Thermal Boundary temperature (A new term: It is the region where air and land or air and water meet to the point where the mass of the constituent is 1 gram. For distilled water roughy 1cm, for silica land roughly 3mm for ambient air roughly ooops 8mx1cm^2, (not 450m, sorry, slugs/grams, whatever...).) It is roughly where the conversion of solar UV downwelling becomes Earth IR upwelling. (In thermodynamics it would be the gray bodies surface.)

When the boundary region reaches a thermal imbalance we see advection wicking it away. When the imbalance is persistent we get a combination of advection and convection, leading to an expansion of the boundary zone, to the point of changing the normal altitude we should see a change in the state of water in the air, both adiabatic liquid and/or ice. The warmer the boundry the broader it becomes; however, it is keyed to Earths vapor pressure and the state of matter characteristic of water.

Hence, if we have a few seasons like 2009-2011 eventually the circulation changes until the system can return to a kind of entropy. What I think we are seeing is similar to Ians observation elsewhere, of another 2006, where there had been a large thermal flow out of the temperate zone in 04-05.

The low sea ice is more a indication that the system is in the process of removing a thermal reserve. By this Fall the sea ice levels should get close to the 07-08 values, if I don't miss my guess. It really depends on how fast the system recharges.

As to your weather, once that heat is dumped you have a large increase in moist air and cooler temperatures..., as the boundary zone contracts. Hence, increased snow or rain near the polar regions, whether its, Siberia, Alaska, the Yukon, the UK, South Africa, or Austrialia... (The odd observation is, there does not appear to be an increase in precip. on polar land surfaces, such as Greenland or Antarctica. It must be related to the return flow, with colder, drier polar air masses, picking up the boundary moisture as it moves southward...)

[Wiseacre]

There is currently much debate on this subject, but it is ridiculous to draw conclusions from a small number of years. There has definitely been a shift in the synoptics in the northern temperate region in the last 5 years to more meridionality (blocking) and this has resulted in colder winters and summers for the UK and parts of W Europe. There does appear to be an element of story shifting and backtracking on the claims made a few years ago that we would never see snow again in the UK.

The reality is that there will be winners and losers in any change of world climate however it is caused. Trying to make computer models fit the synoptics is just as crafty as trying to make the temperature record fit the curve!

[ldavidcooke]

Hey Wiseacre,

For definitive or near precise values, concur. Its the problem of figuring out the functions first. So far most models are large scale top/down. I figure we need a bit more empirical work first. The problem it costs tax money to perform a field campaign. I can just imagine being in one of the leading Climate Science teams knowing you're, "dammed if you do and dammed* if you don't"... (*Note: Misspelling of explictive on purpose.)

(Done right we need some form of Argo buoy for the atmosphere. Kind of like a helium balloon that captures/dumps condensed water vapor to vary altitude. The problem is finding the right materials and not impacting air traffic.)

[ChaserUK]

Is this for another thread but what I have noted is lack of sunspots. We are supposed to be at solar max - no where to be seen sunspot-wise (forget coronal holes causing geomagentic activity). This follows a historic quiet period of the sun since records began. Are we not now experiencing a cumulative effect of what is being discussed here and the sunspot (lack thereof) factor.

[Anabolic North]

Melting Arctic does not cause UK snow.

Nonsense...you should all be ashamed of yourselves. and who says the Arctic is melting anyway?

And what about the record levels of Antarctic ice?

[ldavidcooke]

Hey Martin,

Now you know a picture is....

[Wiseacre]

You should not be so confident in your view, Martin. Whether we like it or not, there has been a decline in the size of the Artic sea ice area and the volume of ice, both in the summer and the winter. With such a shift in the thermodynamic balance of the atmosphere/sea system there is very likely to be an effect or two and not necessarily restricted to the Arctic area. I agree that it is not possible to directly connect ice loss with cold winters in the UK, but the likely change in the temperature contrast between the tropics and the poles as a result of the ice reduction is likely to impact the position of the polar front and hence the distribution of the pressure systems in the Northern Hemisphere. I am not ashamed of conceding that.

[John Mason]

It's certainly an interesting topic. The focus of the current research is the behaviour of the Polar jet, which, like a river entering the lowlands from the mountains, has slowed and developed bigger meanders. Given that a key driver of this jet is the temperature gradient between the Arctic and the temperate zone south of the jet i.e. the Polar Cell and the Ferrel Cell, and given that the Arctic has warmed over twice as much as anywhere else on the planet, it follows that the driving force has eased off as that temperature gradient has decreased in magnitude. The enhanced meandering then permits Arctic air to have an easier time of it in penetrating southwards; plus, the slower eastward progression of the waves leads to more prolonged periods of one weather-type or another. Recently this pattern has kept us stuck on the Polar side of the jet for a prolonged period: however, that is simply where we are now and the opposite could happen too, where we become trapped in the middle of an upper ridge on the warm side, bringing prolonged warm dry weather - as has indeed occurred across large parts of the USA, where severe drought has resulted.

All in all this is something to watch for the simple reason that it brings major problems to agriculture, which in turn could lead to substantial hikes in food prices on top of those already experienced, which are more a reflection of the massive increase in global oil prices in recent years. My advice is start growing your own, if you have not already, and get good at it!

[John Mason]

This new paper at PNAS is worth a look too:

http://www.pnas.org/...000110.full.pdf

[ldavidcooke]

Hey John,

The issue is not that the speed has dropped; but, that meanders have developed. In addition, though the surface level Summer temperatures have risen, the Winter time and Upper Level air has not warmed. At least the warming that has occurred has in essence radiated out into space and is greatly diminished in the Polar cell return flow. That I think is the main issue, the thermal increase at the surface has increased the amount of air parcels in the Arctic which ends up expanding the Polar Cell pushing the UL winds into the Hadley Cell region. The interaction at the edges is what is giving rise to both the "wild weather" and the meanders.

The Ferrel cell has always been a, " if come, maybe " kind of feature. Similar to the " feeding jet " of a blackhole, it has the character of existing mainly where there was a clean Hadley/Polar convergence, where the in essence "outer layer scud" mixed and rotated above the convergence acting as a form of UL bridge. The more erratic the convergence the greater the outer layers were shed and in essence fed a secondary circulation cell. At the current erratic flow the Ferrel cell really is not an observable feature as the strong counter rotating features are driven by the thermal UL differences between the higher latitudes and the surface level in the lower latitudes. In essence, in the past the circulation cells were more like a closed system, very little energy was exchanged. (Any exchange was purely the energy transferred at the surface or ground level by ocean surface currents.).

Once the convection energy changed the Ferrel cell broke down, and the interaction at the Polar/Hadley convergence increased. It is the energy transferred at the convergence zone, further pushed by the added convection in the former polar region caused by higher sea surface temperatures that is responsible for most of what we are seeing. At the same time that the upper level of the Polar cell has pushed South the surface level of the Hadley cell has pushed North. In essence, no more closed cell convergence; but, constant convection cells both rising and the return flow.

[John Mason]

No it's both speed and meanders if Francis & Vavrus are correct. A lot of their recent work has involved assessing both windspeeds and meander latitude.

[ldavidcooke]

Hey John,

That's the point, they aren't right. The wind speeds within the Polar Jet Stream have not diminished. The only real effect is that the ground speed has changed. Increase the ground to be covered under a wind speed that has not changed and yes you could interpret that as a reduction in ground speed; but, that is disengenerous at best and fraud as a possibility. This is the type of science that infuriates the reasonable against the cause of the "warmists" pov. A little tweek here a contentious interpretation there and it is clear that the conspiracy against honest examination of the facts feeds my personal anger over conclusions which misrepresent the facts and fuels my personal disgust. That both sides use similar misrepresentation does not absolve either party, they simply expand the disdain of the public at large.

[John Mason]

So all their years of study of the subject count for nowt because you say so? Forgive me, but that's really not very objective!

[ldavidcooke]

Hey John,

Its simple really, if there was a reduction in the UL wind speed I could accept their "years of expertise". No they were not measuring wind speed ; but, the progress of an air parcel as it advance on the circumference of the Earth, please... Read the paper and the examination if you question my interpretation. If you are that concerned that they are being honest brokers have the folks at Skeptical Science have them submit a guest article. I will be surprised one if they will open their examination methods beyond the public satellite monitoring of UL cloud features and their advance over the ground. This is not a valid measure of a body of air, it is a measure of the effects of its passing. Its like trying to measure the speed of a passing lorry by the displacement or wind speed of its passing...

I find that disengenerous at best! I really cannot express my full displeasure in a public forum, which is probably a good thing...

Put another way, if the exhaust of a car exits the muffler at a rate of 100km/hr how fast is the car moving...?

[John Mason]

Here's the graphic in question:


This graphic depicts how the drop in high-altitude winds in autumn over the past 30 years has closely tracked the decline in Arctic sea ice (dashed line). The rapid warming of the Arctic has reduced the temperature difference between the Far North and temperate regions, slowing down the jet stream and leading to more persistent, or “stuck,” weather patterns. (Jennifer Francis, based on data from the National Center for Environmental Prediction, National Center for Atmospheric Research, and National Snow and Ice Data Center)

[ldavidcooke]

Hey John,

That is not the Jet Stream, try the graph for 250mb.