This webpage from the Danish Centre for Ocean and Ice has interesting graphics showing the temperature of the arctic above 80 north since 1958 using the climate reanalysis ERA40.
I have made an animation with 2 second frames.
I can add 2010 later.
Warwick, Just because the air temperature is above 273K (0C) does not mean the ice will melt. Heat transfer by convection (natural or forced) is proportional to the temperature difference. If delta T is small there will be very small amount of heat transfer which may not be sufficient to overcome the latent heat of fusion. However, ice has an emissivity/absorptivity >0.95 (close to a black body) in the infrared wavelengths so will absorb radiation from the sun when the sun shines at the poles (around half the year) and this energy will cause the ice surface to melt and this in turn may even allow some evaporation if there is a wind. When it is dark the ice will radiate to space. The variations particularly in the dark months maybe associated with clouds, winds, and measurement errors associated with water vapour and ice particles in clouds.
Peterb,
Sorry but you have it wrong. The reflectivity of ice covered with snow (which is the general case)is 80 to 90 percent from Solar input. The incoming Solar radiation is mostly visible, with some near IR, all highly reflected. The cold ice/snow has a high emissivity only at much longer wavelengths than Sunlight (unless it is real dirty), so the ice/snow is losing heat by emission even in Sunlight near the poles. The air convective heat transfer is relatively low, so only a small thermal inputs are obtained unless the air is significantly warmer that freezing, and the wind fairly strong. Sea ice is a different story, and is melted mainly from underneath by water flow removing heat faster than topside radiation out can replace. Bare patches of ground can absorb more Sunlight, and can melt close patches of ice. The evaporation only depends on the temperature, not if it is solid or liquid. The radiation to space is dependent only on the degree of clouds, whether it is Sunny or not.
I notice that since 2003 the warmer than melt period seems to have decreased in magnitude and possibly duration!!
Outside the yearly warm period the temperatures appear to vary a lot.
What are the claims of the recent Arctic temps being substantially higher than normal based on??
First thing I noticed to. The summer/above zero temps vary the least.
Why the colder months vary more is surely scientifically very interesting.
Warwick, I meant to say great post.
Is there some way that the animation can be downloaded? If not would you be so kind to email it?. I think it would be worth using in a presentation.
Leonard Weinstein, maybe I should have put up a few links and better explained my comments.
Here is some information that might help you.
physicsworld.com/cws/article/print/17402. The spectrum from the sun peaks in the UV-visible light range of 0.4 to 0.7 micron wavelength but there is considerable energy flux in the wavelengths 0.7 to 4 micron where ice, snow and water absorb.
This article may help with emissivities for ice in visible and near infra-red
www.avalanche.org/~moonstone/1991%20cssa%20symposium/REMOTE%20SENSING%20OF%20ALPINE%20SNOW%20COVER.htm (can not help about the missing figures but maybe you can access the article and/or some of the references)
This is a link for the infra-red range 4 to 14 micron
www.icess.ucsb.edu/modis/EMIS/html/em.html
The point I was trying to say is that some of the variations in the colder months maybe are instrument error due to interference from clouds (or blizzards)
The main point, however, is that there has been no increase in measured average temperature over the time when CO2 has been increasing. At the poles the humidity is low so any effect of CO2 should be more obvious.
It is very likely that GISS surface temperatures in high latitudes are the result of models (data manipulation) rather than measured temperatures.
@ftm,
During the most pronounced Arctic warming of the last century from 1919 to 1940, the increase of winter temperatures versus summer were particularly high, in detail: www.arctic-heats-up.com/ The reason concerning the winter season is on one hand that there is little or zero direct influence by sun ray, and on the other hand the only direct heat supply into the atmosphere comes from the Artic Ocean or the nearby seas, whereby it is worth to note that usually the maximum sea ice extend appears during the late spring time only. This is certainly a very interesting scientific question. But what to expect? Although the first Arctic warming started almost 100 years ago, science has paid little attention to this very basic question.
Added Monday 25th Jan 7.30am: I have an old page from 2000 comparing Isfjord Radio to neighbours, I wonder how real was that sharp warming between WWI and WWII.
I am grateful for your work. Thank you!!
I am spending all my time on this exposure of climate science fraud. I have stored archives and found ways to contact people. But today I spent reading climateaudit (link below) and most of the commentators were bemoaning the fact that the UK Parliamentary investigation won’t be effective. So I have been emailing this link to anyone I can find who is in a position to publish.
Samizdata (see bottom link) is an awesome site full of intelligent people. On January 10, one of their contributors wrote about Climategate being similar to the Cold War. But the best part was the comments section. The contributors there had some realisticsuggestions for getting past the news blackout on this issue. They suggest we concentrate on Pachauri, as it will allow politicians to save face. And that may be one of the single biggest hurdles we have to overcome.
As we speak:
NASA is under scrutiny:
climateaudit.org/2010/01/23/nasa-hide-this-after-jim-checks-it/#comment-217428
But what politician is going to attack NASA, NOAA, etc. If you look at NASA’s site today, they have a brand new explanation (1-21-10) for everyone to read. climate.nasa.gov//news/index.cfm?FuseAction=ShowNews&NewsID=248 Gavin Schmidt has smoothed over the arguments raised by KUSI tv.
The CRU is under scrutiny:
blogs.telegraph.co.uk/news/jamesdelingpole/100023449/wow-uk-parliamentary-investigation-into-climategate-may-not-be-a-whitewash/ But the news media and the politicians will do their best to divert attention to the religious, or political, or social divergences among skeptics.
This is the article I want people to see. The best tactics I’ve seen are here:
www.samizdata.net/blog/archives/2010/01/cold_wars_1.html
Thank you for your attention. If you do not have time for this, can you refer me to someone who might? Or how might the scientists fighting this find a website where they can gather together to participate against political will?
Kathryn Ubl
Librarian
Added 9.15pm 24 Jan: Thanks for contributing your say in an unfamiliar place Kathryn. The background of this blog is fairly narrowly in the empirical science – I have been critical of the Jones et al work from CRU since 1991.
It has been said before that IPCC AGW began around the time the Berlin wall came down in 1989 – although it was many years before it gathered much strength. All of us old hand counter IPCC types have dug back into old records looking with interest at who was with who at this or that climate conference. We must remember the cold war lasted for 40 years and must have been a colossal drain on global economies – I have not seen the figures set out but it must have been a major factor in the demise of the USSR. The IPCC AGW campaign has increasingly in the last year being understood as a huge socialist wealth redistribution scheme – but whether it was on the scale of the cold war in terms of wasting resources – I do not know. Lately we see climategate – plus the 3 inquiries – then the NASA email issues – now the crescendo building over the very head of the IPCC – will take the whole AGW issue backwards a long way during 2010. On the other hand, all this is yet to see much exposure in the MSM, at least in Australia.
Hi Warwick,
I wonder if you read my post in Climate Sceptics on January 21st about the Danish Center temp graphs and got the idea of making your superb animation. Congratulations, I will use it in my website in Spanish with the proper credit, of course.
I have been alerting since then other Spanish debate forums and they are quite surprised and shocked. Warmist really hate me!
Added Sunday 24th 6.25pm: Yes Eduardo, thanks very much, I always check through the CS mails and never miss your contributions. I used 10 yr old Animation Shop 1 (c1998) to build the file. You are welcome to anything here. Re the warmist forums, we can only guess where ClimateGate will go this year and there will be enormous sums spent on damage control – but it will not be pretty for the IPCC cohorts.
Peterb,
I am a skeptic, but I am a stickler for accuracy. There is only a bit over 6% of Solar energy beyond 2 microns, and only a bit over 2% beyond 3 microns. By 4 microns, all the remaining Solar energy (out to far IR) is about 1%.These are so small, that the reflected energy (0.4 to 2 microns has 96% of the Solar input energy) totally dominates the energy balance. The reflectivity of the ice with snow remains high to over 2 microns, so even the few % in that range are minor effects.
Leonard Weinstein have a look at this environmentalresearchweb.org/blog/2010/01/soot-and-glaciers.html You can even download the Warren and Wiscombe 1980 paper if you follow the links. You will find that reflection is less than you think and heat absorption by ice much higher. Hopefully these sort of measurements will finally kill off any thoughts about CO2 increases melting glaciers or arctic ice.
Might interest you. An open source initiative. www.bestinclass.dk/index.php/2010/01/global-warming/