No mention of missing “M’s” here in this press release from University of Melbourne
Melting sea ice has been shown to be a major cause of warming in the Arctic according to a University of Melbourne study.
Findings published in Nature today reveal the rapid melting of sea ice has dramatically increased the levels of warming in the region in the last two decades.
Lead author Dr James Screen of the School of Earth Sciences at the University of Melbourne says the increased Arctic warming was due to a positive feedback between sea ice melting and atmospheric warming.
“The sea ice acts like a shiny lid on the Arctic Ocean. When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it.”
“What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise,” he says.
Using the latest observational data from the European Centre for Medium-Range Weather Forecasting, Dr Screen was able to uncover a distinctive pattern of warming, highly consistent with the loss of sea ice.
“In the study, we investigated at what level in the atmosphere the warming was occurring. What stood out was how highly concentrated the warming was in the lower atmosphere than anywhere else. I was then able to make the link between the warming pattern and the melting of the sea ice.”
The findings question previous thought that warmer air transported from lower latitudes toward the pole, or changes in cloud cover, are the primary causes of enhanced Arctic warming.
Dr Screen says prior to this latest data set being available there was a lot of contrasting information and inconclusive data.
“This current data has provided a fuller picture of what is happening in the region,” he says.
Over the past 20 years the Arctic has experienced the fastest warming of any region on the planet. Researchers around the globe have been trying to find out why.
Researchers say warming has been partly caused by increasing human greenhouse gas emissions. At the same time, the Arctic sea ice has been declining dramatically. In summer 2007 the Arctic had the lowest sea ice cover on record. Since then levels have recovered a little but the long-term trend is still one of decreasing ice.
Professor Ian Simmonds, of the University’s School of Earth Sciences and coauthor on the paper says the findings are significant.
“It was previously thought that loss of sea ice could cause further warming. Now we have confirmation this is already happening.”
re; black carbon (soot)
The interesting thing about that is that it accumulates on the surface of multi-year ice. The stuff floats so any partial surface melt just concentrates it on the snow or ice surface. If the ice melts completely then it vanishes never to be seen again.
This is probably a negative feedback where as more multi-year ice disappears the less black carbon there is to accelerate additional melting. New ice won’t have the build-up on it and thus will be more likely to become multi-year ice once again only this time with a more reflective surface.
This mechanism works the same way on any multi-year ice where there is a partial surface melting including glaciers at lower latitudes which are much more subject to partial surface melts during the warmer months of the year.
Black carbon can only travel, at best, a few thousand kilometers from the source before it settles out on the surface. This handily explains why the northern hemisphere is experiencing much greater multi-year ice melt. The southern hemisphere has nowhere near the same amount of black carbon sources and most of Antarctica is well out of the range of any of them whereas the Arctic is well within range of the biggest sources on the planet.
starzmom says:
So this positive feedback of ice melting causes warming and more ice melting. So exactly why is there more ice now than any time in the past 9 years on this date? Must have missed something in that analysis.
There will always be interannual variability – that’s the nature of the climate system. NSIDC say:
http://nsidc.org/arcticseaicenews/
AlanG says:
April 30, 2010 at 3:14 am
The cheque from Big Oil finally came through 😉
OR just press the Control (CTRL) button and spin the mouse wheel, for those of us in the 21st century…..
Terry says:
April 30, 2010 at 4:09 am
probably answered already but….
Check out the page source. You can add lt blockquote gt (lt=less than ) and an end-tag (with a / before the word). i in there does italics, u underline, etc. Remember to do the / in the closing tag.
It’s just HTML, see the page source. It’s a pain, but I’m a developer so I’m happy to mess with such stuff. I’m also getting it wrong 25% of the time (like all good developers – that’s why software has bugs. No other engineering profession is so fault-tolerant, I love it!)
Beyond the ’cause-effect’ thing (melting causes warming?) – no mention of subsequent clouds and refreezing?
Study your OWN icecap, you Aussies ! Ha ha ha!
What a load of old cobblers this report is! Seems these guys have forgotten their basic physics about the enthalpy of fusion. Ice melt is endothermic, meaning that the system absorbs energy on going from solid to liquid at 334j/g.
This means that the air temperature above melting ice is always close to zero. The atmosphere transfers little energy to the ice and only has impact on sea ice melt. The sun and ocean are the main providers of the huge amount of energy needed for the melt, with the sea providing by far the largest proportion.
The effect of the sun is less than would seem reasonable because the angle of it’s rays is low in the Arctic and is mostly reflected, of both ice and water.
The final pieces of the puzzle are provided by atmospheric and ocean current strength and direction, which effect the rate the melting sea ice is swept out the Arctic basin to melt in the warmer southerly seas.
It is also interesting that these people don’t mention the dramatic sea ice recovery since the 2007 minimum – although this hardly supports their shaky hypothesis!
Two effects in search for a cause?
And this is made by an University? OMG… worst that we thought.
Tim Clark says:
My understanding is that the warming of the first few decades of the 20th Century was associated with increased solar irradiance. At that time the anthropogenic greenhouse effect was too small to be distinguishable from natural forcings – it only rose out of the ‘noise’ in the last few decades.
“OR just press the Control (CTRL) button and spin the mouse wheel, for those of us in the 21st century…..”
JER0ME !!!!! Ta! Even t nearly 60 I just joined the 21st century!
RockyRoad says:
April 30, 2010 at 3:50 am
(Maybe they believe CO2 was being captured by Arctic ice and, being fizzy, it WAS the flavor of the ice after all!)
Woo hoo! I was right, it was all about the flavo(u)r!!! 🙂
I guess it depends on where you look. Is this is the area they decided to label “Rotten” because it doesn’t fit their trend?
Trends in thickness and extent of seasonal pack ice, Canadian Beaufort Sea
http://imb.crrel.usace.army.mil/pdfs/Change_in_Beaufort_SeaIce_1990s.pdf
GEOPHYSICAL RESEARCH LETTERS, VOL. xx, Lxxxxx, doi:10.1029/2005GLxxxxx, 2005
Discussion
[14] Surface air temperature increased by about 2.5ºC over a wide continental area south of Site 1 during the last quarter of the 20th century (IPCC 2001). Because decrease in sea ice is a common supposition in a warming climate, the lack of unequivocal change in Beaufort seasonal ice is surprising.
Conclusions
[22] Moored sub-sea sonar has revealed a small thinning trend (0.07 m/decade) in seasonal pack ice in the eastern Beaufort Sea 1991-2003, and a larger trend (0.12 per decade) to greater ice concentration, meaning more ice in summer.
[23] The net change in draft does not exceed the accuracy of measurement (±0.1 m). The trend has low significance since seasonal and inter-annual variability are large.
[24] Data from conventional ice reconnaissance over the last 36 years suggest little net change in ice conditions over the Beaufort shelves, despite dramatic decrease in summertime ice over the south-western Canada Basin.
[25] Measurements of surface air temperature at a nearby coastal site reveal warming by 1.6±0.4°C since 1974. The estimated impact of warming since 1991 is reduced ice growth by 0.04 m. Impact on ablation is difficult to quantify.
[26] Definitive evidence for climate-change impact on seasonal ice will require time series much longer than those presently available.
[27] Mechanisms other than air temperature – snow cover, ice circulation and ridging – are plausible contributors to variability and trend in the thickness and extent of seasonal ice.
If only there were warm water currents coming from the equatorial regions. If only they released an increased amount of heat from the oceans to cool the planet in the arctic regions, and if only this effect would increase when warming causes ice to melt, increasing the area that the warm water could radiate to, thus cooling the planet. If only the melting ice turned into cold water that then got carried by those same ocean currents to equatorial regions, cooling them off. If only the amount of heat that got moved around this way was hundreds or thousands of times the change from albedo from the fluctuating ice. If only this were true then the ice cover and temperature would just fluctuate between some upper and lower limits. Less ice, more cooling, more ice less cooling. If only that were true, and if only we knew if the cycles were 60 years or so in length like the ones observed in the historical record. But, since we can’t rely on the historical record, all we are left with is the hysterical record.
Too bad about that. Hmmm… is the hysterical record cyclical too?
OT News: 30,000 Anti-Global Warming Scientists Can’t Be Wrong
Nature Magazine, the academic journal that introduced the world to X-rays, DNA double helix, wave nature of particles, pulsars, and more recently the human genome, is set to publish a paper in June that shows atmospheric carbon dioxide (CO2) is responsible for only 5-10% of observed warming on Earth.
http://canadafreepress.com/index.php/article/22624
Icarus says: April 30, 2010 at 6:41 am “There will always be interannual variability – that’s the nature of the climate system.”
And then you go on to quote NSIDC on why there was a late Arctic ice spurt this year. However, you seem to be missing a key point: It is not just the late spurt this year. It is the continued high level. In fact, for today’s date, the largest ice extents measured by ASMR-E (which started in 2002) occurred in 2008, 2009, and 2010. Ice recovery has not just been a one year freakish event.
Likely, 99% of the commentators on this blog understand the albedo concept, but from the abstract and press release, it appears that this study oversells Arctic albedo. The angle and the increased travel through the atmosphere reduce the effect in the Arctic.
Richard111 says:
April 29, 2010 at 9:56 pm
Ice melts at 0.01C and remains at that temperature untill ALL the ice has melted.
Maybe it’s just semantics, but this is not quite true when dealing with sea water (brine).
Melting or freezing of water is simply a shift of equilibrium: in your example, more water molecules are entering the liquid state than the solid state, 0 C for ice in fresh water. However, in brine, the colligative properties of water prevent water molecules from entering the solid state at 0 C, resulting in more water molecules entering the liquid state at temperatures BELOW 0 C (that temperature being dependent on the salt concentration of the water).
Yeah, I know, it doesn’t make a big picture difference, but we don’t want warmistas dismissing valid arguments by claiming we lack basic scientific understanding.
“Could this help explain the repeated observation that the sea ice grows in the winter and shrinks in the summer?”
That’s just Crazy Talk, man. Crazy Talk!!!
Mark Serreze writes: “April 6, 2010
Cold snap causes late-season growth spurt
Arctic sea ice reached its maximum extent for the year on March 31 at 15.25 million square kilometers (5.89 million square miles). This was the latest date for the maximum Arctic sea ice extent since the start of the satellite record in 1979.
Early in March, Arctic sea ice appeared to reach a maximum extent. However, after a short decline, the ice continued to grow. By the end of March, total extent approached 1979 to 2000 average levels for this time of year. The late-season growth was driven mainly by cold weather and winds from the north over the Bering and Barents Seas. Meanwhile, temperatures over the central Arctic Ocean remained above normal and the winter ice cover remained young and thin compared to earlier years. ”
A cold snap? From where? How come Mark, this is ‘GLOBAL WARMING”, and since the Arctic is getting warmer of all, where the heck is this “cold snap” coming from?
So… warming causes sea ice to melt, and melting causes warming? Why haven’t we exploded yet?
Oh My God!
Well Ive been unnecessarily polite regarding my self as a layman. Now I realized that im equipped with an ability that appears to be in shortage whithin climate science…LOGIC!!! Lets congratulate the Professors to find an explanation why ice melt! Fantastic!!! Good Work!! Ice needs warmth to melt!! WOW!!!
Then you only have to describe why ICE grow!!! Only 50% left to find the answer to the question to icingbehavior. Im gonna give you a cheat start…it needs to get coooler!!!! You`ll get that for free!! No strings attached !
You also havent even started on the second question how come Antarctic ice is growing during the same period? And is there NO I mean NO ? Natural explanations to even the slightest changes in polar icecaps? A forbiddeen thought?? For herectics only??
But please please withdraw the stupid claim that you know that icecover will decrease in the future. You just hoping it will so it fits your religion.If your honest you have no explanation to why its grown since 2007 and you havent the faintest idea what will happen whith future icecover. Because you have made a huge misstake from the beginning. If you think the icecap history started in 1979 you better think again!! and again!! and again!!1
You are equipped with a single needle “co2” and you claim you know its position in the climate haystack you are trying to build around it!! You dont semm to be able tyo get even the first traws in the right order.And with a severe dyslexia on statistics its gonna take you forever!!!
The great global warming blunder. I m so angry I think ill become an climate scientist myself! What do I have to do? Dig into the bottom Corn Flake box and find myself an IPPC “your in!” certificate?? Whith a disclosure ” If you question climate sensetivity to CO2 you`ll need a real certificate”
I would say less ice is a secondary effect of warmer sea (and air), but I doubt it is such a big positive feedback.
Warming, cooling, warming and again about to cooling pattern in Arctic ocean is obvious:
http://climexp.knmi.nl/data/ihadsst2_0-360E_60-90N_na.png
Alas, there is no correlation with CO2 rising, except 1980-2005 warming trend which just obviously finished.
If we agree that colder sea (and air as a secondary effect) means more ice, how NSIDC can claim the 20th century Arctic ice history like this
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg
if combined record of SST and met stations is like this?
http://climexp.knmi.nl/data/icrutem3_hadsst2_0-360E_66-90N_na.png
LearDog says:
April 30, 2010 at 6:51 am Study your OWN icecap, you Aussies ! Ha ha ha!
BTW the magnetic south pole is travelling to Australia….they got to study if this will affect how high the Kangaroos jump above the ground or how deep politicians thoughts are…
The next step for these “atmospheric scientists” (they live up above, at the “Topus Uranus”) is to make a cooking range with four hairdryers as heating sources…that will be more environmentally friendly.
Phil Jones and the CRU are not the only loony tunes at East Anglia:
Wildlife documentaries invade animal privacy rights, claims leading academic
http://www.telegraph.co.uk/science/7653305/Wildlife-documentaries-invade-animal-privacy-rights-claims-leading-academic.html
Gosh. I never knew bears had privacy rights under the Constitution. But of course this is loony land where they can have a cam on every street corner and dog shit and its ok. Just don’t invade the animal’s privacy.
“In the study, we investigated at what level in the atmosphere the warming was occurring. What stood out was how highly concentrated the warming was in the lower atmosphere than anywhere else. I was then able to make the link between the warming pattern and the melting of the sea ice.”
According to the IPPC, the signature of AGW is heating in the mid upper atmosphere. What gives?
This young man comes from East Anglia, it is very flat, very rural, little to do.
Inbreeding!