WEIRD WEATHER: Shifting summer winds may be to blame for everything from a precipitous decline in Arctic summer sea ice cover to this year's floods and wildfires.
Image: Flickr/Kaibab National Forest
A new weather pattern that sends blasts of warm southern air into the Arctic each June has fueled the recent, dramatic decline of the region's sea ice, according to a new government-funded study.
But that is not all it has done, the analysis suggests, linking the shifting summer winds to record thaws of the Greenland ice sheet, unusually wet European summers and Rocky Mountain wildfires.
Researchers say the switch from light, variable east-west winds to stronger, warmer blasts of southern air appears to have strengthened a climate feedback loop they call "Arctic amplification."
As the amount of ice that melts each summer increases, it opens larger and larger patches of dark Arctic Ocean waters that absorb more heat than the reflective ice they replace, a process that accelerates Arctic warming.
"The winds in the summer Arctic used to be light and variable," said the study's lead author, James Overland, a researcher at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory who studies the Arctic climate. "Now the winds tend to set up blowing from the Bering Strait across the North Pole and out towards the North Atlantic."
That helps push ice out of Arctic waters. It also makes upper-level winds that normally blow from west to east wavier, wiggling farther north and south, a change that can wreak havoc on weather in Greenland and midlatitudes in North America and Europe.
The new study suggests the phenomenon had a hand in the hot, dry conditions that helped spark record-breaking wildfires in the Rocky Mountains and a heat wave in Russia in June, and cool, wet summers in the United Kingdom since 2007 -- including record rains and floods that year and again this year.
Surprises for scientists
It is the latest surprise for researchers who study the Arctic, a region that is warming twice as fast as the global average.
Scientists were shocked in 2007 when Arctic sea ice cover dipped to a record low nearly 40 percent below the 1979-2000 average. But that historic melt season was bested this summer, when sea ice cover dipped an astonishing 16 percent below the 2007 mark.
"We're in a new normal for Arctic climate," said Overland, whose work was published yesterday in the journal Geophysical Research Letters. "We keep underestimating the importance of Arctic amplification -- that you have a little bit of global warming, but the special processes in the Arctic are accelerating the changes there. We really don't know how fast or where this is all going to go."
Another surprise, Overland said, is the link his study found between the blast of summer air flowing into the Arctic each June and persistent high-pressure weather systems that have produced unusual summer warmth in Greenland for the last six years.
"All of a sudden, Greenland -- which we thought had a lot of variability, with some years warmer and some years colder -- looks like it's stuck in a warmer weather pattern in early summer," he explained. "There's a good chance that this will continue."
The effects of that warmer weather pattern were unusually dramatic this summer, as a series of strong high pressure ridges produced unusual surface thawing on the Greenland ice sheet and a record seasonal melt.
Greenland's largest thaw
Roughly 97 percent of the surface of Greenland's ice showed signs of thaw for a few days in mid-July, covering a larger area than any other melting event since satellite monitoring began 30 years ago, NASA said.
Researchers observed a similar but shorter event in late July. And few weeks later, on Aug. 8, Greenland set a new summer melt record, surpassing the 2010 mark with four weeks to go in the 2012 melt season (ClimateWire, Aug. 16).
See what we're tweeting about
21 Comments
Add CommentHow is Scientific American going to try to link this to additional atmospheric CO2?
Reply | Report Abuse | Link to this@Sisko,
Reply | Report Abuse | Link to thisThe link is there and SciAm is just reporting on it.
Paraphrasing: A new weather pattern (a.k.a. a change in the climate) is the product of Arctic amplification, which we "keep underestimating," of global warming.
Just how much evidence would it take to convince you that the link is real? This is not a computer model, but observations in the field of a climate we have not seen before. In fact, these observations exceed the predictions of computer models.
In the rational world of risk analysis, even if there were doubts about the link it would be prudent to react as if it were real. Only with our planet's climate do we accept risks of this magnitude.
@SteveO
Reply | Report Abuse | Link to thisWhat Sisko is asking is how do we connect global warming with increasing CO2 levels....
One such connection would be:
http://www.nature.com/nature/journal/v484/n7392/full/nature10915.html
Showing that global warming was preceded by increasing carbon dioxide concentrations during the last deglaciation.
I'm far from a climate person, and I hope I'm citing the above correctly. I feel a lot of environmental people are stuck being "believers" and therefore can't make a decent argument proving their point. This is an important issue because there is a point to be made!!!
I get the point.
Reply | Report Abuse | Link to this@Sisko
Reply | Report Abuse | Link to thishttp://www.newscientist.com/article/dn22374-runoff-from-greenland-may-weaken-carbon-sink.html?cmpid=RSS%7CNSNS%7C2012-GLOBAL%7Conline-news
To summarise, the changing Arctic climate will cause much greater quantities of melt water, which may disrupt the Atlantic Meridional Overturning Current (AMOC), affecting the capacity of ocean waters to absorb CO2.
So, Sisko, SA doesn't have to make the link, as it's already been made.
I think you best be served at just concentrating on your own job in coding and not get fired there. The heat is not uniformed around the planet because of it's historical measurements. And trends are predictable. I don't know what your job has to do with historical facts and probable futures. Nothing in this case. Do you work nights, or are you just staying up at night until you begin to think fuzzy?
Reply | Report Abuse | Link to this@ turtle 2258, people like you really don't help any discussion. You don't have an argument so you attack Priddseren. Do you feel good about the brilliant contribution you made? I feel the ads about this guys stepmother's cousin 3 times removed who makes a gazillion Dollars working day and night on her computer, are more informative than what you are telling us.
Reply | Report Abuse | Link to thisI'm sorry. I didn't mean to attack anyone personally. Why should I do the same thing that you and he does, it would just make me the same? I should've just attacked his attack on Lauren Morello and the bogous beleifs he's beleiving. What's your argument? Looking for an opportunity to get offended? I don't know. How am I suppose to erase what I've said and just leave my argument?
Reply | Report Abuse | Link to thisAnd so 60 years of ill-informed and naive forestry policies have nothing to do with wildfires?
Reply | Report Abuse | Link to thisNature's way of dealing with deadfall and under brush is to burn it from time to time in small natural fires. Forestry Service policies have been zero-tolerance for ANY fire. Until, of course the fire becomes utterly massive and our of control. Then the Alarmist's say it's all due to CAGW.
How's that working out for you?
SteveO says:
Reply | Report Abuse | Link to this"In fact, these observations exceed the predictions of computer models."
In the old days, (before the acceptability of post normal science in climate research) when observations did not agree with the models, it was called falsification of the model. Surely you understand, falsification does NOT strengthen the modality. GK
If you want answers as to why the earth is getting warmer check " precession of earth ". The Northern hemisphere is approaching its maximum tilt towards the sun.
Reply | Report Abuse | Link to thisPrecession has a near-zero effect on the climate. Please do some research.
Reply | Report Abuse | Link to thisRegarding "Greenlands Largest Thaw" on 1 or 2 days in July, the ambient air temperature barely reached freezing for a few minutes. Any melting that did occur was frozen solid again in minutes. Ice cores show this happening about every 150 years. This one was right on time as explained by NASA when it was first reported.
Reply | Report Abuse | Link to this""Ice cores from Summit show that melting events of this type occur about once every 150 years on average," with the last one happening in 1889, Koenig, a member of the NASA team analyzing the satellite data, said in a statement."
Nothing happening in the worlds climate now is anything new or unprecedented. Antarctic sea ice is now at a 30 year record high. As one pole gains ice the other looses ice. We've known this since 1979 or longer.
Everything happening now was happening long before humans even took up agriculture. We are just not that powerful.
You are wrong on every level. Please do some actual research before proclaming yourself an expert.
Reply | Report Abuse | Link to thisOh now that hurts!
Reply | Report Abuse | Link to thisGot evidence? :^)
Just more evidence that 7 Billion people CAN destroy a planet.....pity we only have one!
Reply | Report Abuse | Link to thisYes. Mine is on Wikipedia and is quoted in scientific publications every day. Have you got any?
Reply | Report Abuse | Link to thisWikipedia? You're kidding, right?
Reply | Report Abuse | Link to thisIn this post by Steven Goddard, is displayed the temperature chart showing the air temperature at Summit Camp Greenland this summer during the 'melt down.'
http://stevengoddard.wordpress.com/2012/07/25/97-of-greenland-says-that-nasa-is-fos/
Here is the link to Summit Camp and it's current weather.
http://summitcamp.org/status/weather/
So, other than I'm wrong about everything and Wikipedia is science, any more little gems you would like to share with us?
Ok, so you are saying there is no Summit Camp in Greenland? That the weather data he presents is a work of fiction?
Reply | Report Abuse | Link to thisYou claiming that NASA's account of the periodicity of the Greenland melt is simply made up?
Can we at least agree that there is an ice covered island called, ironically, Greenland?
So far you've not offered one piece of evidence but instead, personal attack after personal attack.
Bird/tree/dinosaur/etc.geek,
Reply | Report Abuse | Link to thisYou still offer no evidence. You don't even refute the evidence I offer. You simply attack people and hurl insults.
This is the 2nd biggest reason you side is losing. Your nasty, bitter insulting boorish behavior puts people off from the start. People don't like bullies, especially nameless, faceless bullies on the internet.
The main reason your side is losing, is that your 'evidence' is flimsy at best, and fabricated at worst.
Here is the link to GISS (a.k.a. James Hansen) showing the temperture record at Godthab-Nuuk Greenland.
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=431042500000&data_set=14&num_neighbors=1
I was studying this data set when it suddenly changed and began showing a pronounced warming trend rather than a slightly cooling one. (I have a back up of the data) Scientists and meteorologists I talk to confirmed my observations. Many data sets in the arctic were changed in the same manner.
So please, by all means, let the insults fly, and with it, your credibility.
OK, here's the essential problem. We're putting millions of tons of carbon dioxide into the atmosphere every day, and simultaneously destroying every tree that we can get our greasy overpopulated paws on. With nowhere to go, the CO2 piles up, acidifying the oceans and creating a "blanket" over the earth. We have so much evidence that shows that this is the case that arguing otherwise has become pseudoscientific and [excuse the language] stupid.
Reply | Report Abuse | Link to thisFor a short summary of what will happen if we don't fix this mess NOW, read the recent SciAm article on the Paleocene-Eocene Thermal Maximum.
My apologies for the insults. I have spent too much time "debating" the guy who thinks that electricity is tiny aliens in power cords, and says that he's right because he said so. I need to remember that not everyone is utterly insane.