Above, Dr. Jennifer Francis of Rutgers, and Dr. Jeff Masters of Weather Underground and the Weather Channel, on jetstream changes that may be responsible for changes in extreme weather events in the temperate zones.
“Since the 1980s, Arctic sea ice extent (SIE) has declined at a rate of about 8% per decade during September5, reaching a new record minimum in 2012. The area of summer sea-ice loss would cover over 40% of the contiguous United States6 . Snow-cover extent (SCE) on high-latitude, Northern Hemisphere land areas has also diminished during early summer. The rate of SCE loss during June from 1979 to 2011 of 17.8% per decade is even faster than the loss rate of Arctic SIE (ref. 7). “
Dr. Francis has a new paper just out reinforcing the sea ice connection with information about declining spring snow cover as well.
Abstract:
The past decade has seen an exceptional number of unprecedented summer extreme weather events in northern mid-latitudes, along with record declines in both summer
Arctic sea ice and snow cover on high-latitude land. The underlying mechanisms that link the shrinking cryosphere with summer extreme weather, however, remain unclear.Here, we combine satellite observations of early summer snow cover and summer sea-ice extent with atmospheric reanalysis data to demonstrate associations between summer weather patterns in mid-latitudes and losses of snow and sea ice. Results suggest that the atmospheric circulation responds differently to changes in the ice and snow extents, with a stronger response to sea-ice loss, even though its reduction is half as large as that for the snow cover. Atmospheric changes associated with the combined snow/ice reductions reveal 0 widespread upper-level height increases, weaker upper-level zonal winds at high latitudes, a more amplified upper-level pattern, and a general northward shift in the jet stream.
More frequent extreme summer heat events over mid-latitude continents are linked with reduced sea ice and snow through these circulation changes.
Andrew Freedman has more.
A new study for the first time found links between the rapid loss of snow and sea ice cover in the Arctic and a recent spate of exceptional extreme heat events in North America, Europe, and Asia. The study adds to the evidence showing that the free-fall in summer sea ice extent and even sharper decline in spring snow cover in the Northern Hemisphere is reverberating throughout the atmosphere, making extreme events more likely to occur.
–There is virtually no controversy among climate scientists and meteorologists that massive changes have occurred in the Arctic environment during the past three decades, and that those changes are largely due to manmade greenhouse gas emissions.
Since the 1980s, Arctic sea ice extent has dropped at a rate of about 8 percent per decade during September, which is when the sea ice cover reaches its annual minimum. Arecord minimum was set in 2012. For a size comparison, consider that the area of summer sea ice lost since the 1980s would cover about 40 percent of the continental U.S., the study said.
Spring snow cover extent loss during June has dropped even more precipitously than sea ice cover, the study found, at a rate of about 18 percent per decade since 1979.
The case for a connection between Arctic warming and summertime extreme weather events rests on the Arctic’s crucial role as a pacesetter and shapemaker of the jet stream, the powerful ribbon of upper level winds that steer weather systems from west to east across the Northern Hemisphere.
Because the temperature contrast between the frigid Arctic and the milder mid-latitudes is what drives the powerful jet stream winds that guide weather systems, what happens in the Arctic is bound to have some sort of influence on the world’s weather.
–The new study, along with other previously published research, showed that the decline in sea ice and snow cover has slowed the west-to-easterly component of the jet stream, thereby enhancing the north-to-south waviness of the jet, which leads to the creation of more stagnant or “blocked” weather patterns. In addition, the new study found an association between sea ice and snow cover decline and a northward shift in the jet stream, which allows more warm air to move into the U.S. and Europe during the summer.
Paradoxically, other studies, including work by the same team of researchers, has shown that Arctic warming can actually enhance cold weather extremes in the U.S. and Europe during the winter.
Jennifer Francis, a meteorologist at Rutgers University, co-author of the new study, and the most prominent proponent of the hypothesis that Arctic warming is leading to more extreme weather events, told Climate Central that this study adds further evidence to the growing body of research supporting her team’s conclusions.
“While an observational study cannot pin down the mechanistic cause of the response, our results show a strong relationship between ice and snow losses during summer with heat waves in mid-latitude continents where billions of people are affected,” Francis said in an email conversation.
The cause/effect between arctic change and jetstream is not settled, pound on the table science. Below, an exchange between Dr. Francis and Dr. Kevin Trenberth, a leading researcher at the National Center for Atmospheric Research. Dr. Trenberth is not yet ready to sign on with the theory, but agrees that extreme weather events are increasing, and that we are seeing a “new normal” in climate.
Freedman again:
Judah Cohen, lead seasonal weather forecaster at AER, a weather and climate consulting firm, said the possibility that Arctic climate change is leading to more extreme weather patterns has initiated a flurry of new studies. “I can tell you that I am busier now reviewing journal papers than I have ever been in my career and they are all on sea ice” he said in an email. “I think this will be a dominant area of research and discourse for years to come.”
For her part, Francis is continuing to keep a wary eye on the weather map, convinced that the evidence for Arctic-induced weather extremes will continue to mount.
“As we continue to emit ever-increasing amounts of greenhouse gases into the atmosphere and as the Arctic continues to warm faster than mid-latitudes, we will see the case for the linkage strengthen,” Francis said. “I expect that with every year we will see a clearer response of weather patterns in all four seasons, and new modeling experiments will help elucidate the links in the chain, as well.”
I am at the American Geophysical Union meeting this week, and will be seeing and interview Dr. Francis, Dr. Masters and Dr. Trenberth, among others. Will have more updates and videos in coming weeks.
I’m afraid so dumbassoldguy. You’re missing it once again.
Please don’t tell me my mother wears army boots because she only did it once (camping) and I’ve already thrown them out.
I’m not quite sure what The Dube is talking about here. He’s “afraid so” over what? And what am I missing. Tell me, Dube.
And has everyone noticed how cleverly he inserted “ass” between “dumb” and “old” in my handle? What’s next? Fart jokes or fart noises from a cupped hand in his armpit? And the “your mother wears army boots” reference is so old that Dube’s using it makes me think he may be as old as I am, or even older. If that’s the case, I think we may have an explanation for his seeming senility—he actually may be suffering from senile dementia!
My sympathies, Dube.
Do you understand that heat flow is governed by temperature from hot to cold? That the equations of heat transfer and direction are governed by temperature difference? That means that if the center of the earth is 5700K, the only way to stop heat from from the center of earth is to match it at the surface. You do get that right? So the earth being exothermic geologically, means the surface of the earth is less than 5700K. To be endothermic it has to be more than 5700K. I think I can agree with that. Unfortunately, that means the earth being exothermic has nothing at all to do with the discussion of surface temperatures and solar and geothermal heat flux density. You do know what heat flux density is, yes? If you have a rod that only conducts heat, no radiation, convection, etc. with a sink (cold) at one end, and a source (hot) at the other, which way does the heat flow? So if you have two heat sources at the hot end, which one heats it more? Its just flow times resistance buddy. Doesnt matter anything else. The flows add. The bigger flow wins. Sorry. Your whole argument is a huge flop. The bigger flow causes the bigger rise. Exams over. Advanced students might recognize CO2 as being an equivalent thermal resistance. I know its overly simplified. But flow goes from hot to cold no matter what. Guess I didnt notice that CO2 would make the earths temperature rise whether the surface heated by sun or geothermal. Hey, how bout that? Waddya think fox?
Makes sense to me. Any reasonably bright high school physics student would understand it. Will The Dube?
Dear Christopher Arcus,
Yes, the heat travels hot to cold; hot inner core to colder surface; warm surface to bitter cold space. The net of the whole system (taking into account solar influx) is ~44TW going out (exothermically to the solar system).
If the hypothetical CO2 retained energy was just as large as geothermal, then the in and out would balance. But since the Earth remains exothermic, the amount of CO2 retained energy must be small compared to geothermal.
Hint: If you want to challenge this line of thinking, you must start by claiming the Earth is not exothermic to the solar system – because if it is, then it logically follows that CO2 thermal retention must be very small when compared to geothermal energy (which indeed is very small when compared to solar flux).
Dear Dunboldguy,
I’m sorry I called you a dumbass (but would not apologize it you didn’t rate-me-out).
Dear Kingdube,
I thinks you’re over simplifying the Earth’s Energy budget in a way that might appeal to Judith Curry’s Climate etc’s crowd, play your cards right you may get her to sponsor a paper on the subject. Don’t hold your breath for a peer reviewer though.
Again, The Dube’s discussion of heat flow makes little sense.
If I am now DUNboldguy in The Dube’s mind, and “I’m sorry” is some sort of apology (I don’t understand the last part of that sentence), I say no apologies are necessary. None of us should take ourselves too seriously here—I don’t (and I hope certain unnamed “others” are listening).
Huh? No. No. No. Good grief?! I think I understand your misconception. Its as if you think its a 2 ft water pipe with two sources, one at 2ft, and one at 1ft. THe 2ft is the earths core, the 1ft is the earths surface. The section between 1ft and exit is the atmosphere. The bottom of the pipe just exits as drain. (space) From this you conclude that if the flow in the 1ft entry is great enough, the 2ft entry never exits to space. Wrong. You could put two resistors in series to ground with one current in the top resistor and one in the middle where they join. Current would never go backwards because they are both current sources. Both flow. Its called superposition. So translated, two heat flows are never going to go anywhere but space. And a heat flow at the core of the earth and will never do anything but make the core hotter than the surface, evah evah evah . Wow. Now I understand. And CO2 will only make the surface warmer because its a thermal resistance. OK. Go ahead. Ask a thermodynamicist. I am done. You’re lost. I’m not. I even understand where you are lost. Good luck.
Ya know…this line of thinking I’m speaking to is a stream-of-consciousness. It’s not something I’ve considered before interacting with you lovely folks here on this blog.
But now that you mention it, Judith Curry’s opinion might be worth seeking.
You guys are an odd bunch. It’s hard to understand the “it must absolutely be our fault” position. I mean, maybe it is, but it certainly doesn’t look to be that way.
Surely none of you thinks that if the climate changes it must be because we changed it – like it only changes when we change it. It’s always changed and presumably always will. The question is: how much are we changing it? and to what extent are we changing it in a deleterious fashion?
Almost certainly we are changing it – as trees are, and microbes, and insects, and solar, and geologic processes, and likely cosmic processes, etc.
But I would expect you all to agree that it has always changed without us. It doesn’t need us to change.
We are emitting CO2 – much less than are microbes and insects but nonetheless, we are too. And CO2 is going up. So we are contributing.
The BFD is the hypothesized 2.5-5X multiplier from positive feedbacks. If that is true…Houston, we have a problem. But do you know what evidence has been presented to support this positive feedback multiplier position? The answer is none so far as I can tell. It may exist. It is hypothesized to exist. But after 20+ years and $100’s of Billions of research dollars…where is the evidence of it.
Mann and Hansen don’t speak to it. They speak to the hypothesis, of course. But not to evidence. Can any of you lovely folks point to the empirical evidence of this feedback multiplier? And do you each recognize that without this multiplier we are partially contributing to a 1C rise that almost certainly will be beneficial to all life on Earth?
Tell me that this isn’t a cut-to-the-chase-scene of this whole AGW dilemma?
OK. doobyy, doobyy, eearth to king dub. Wake up dooby! Its one thing to say you don’t agree with a counterargument. Its another thing to say you were never given one. Your memory is slipping. Don’t worry, I am here to help you find it. Not your memory. I mean the evidence used to support positive feedbacks. Its right there in a recent CC article just before this one. And guess what. I gave it to you. Don’t lose it this time Ralphie. Oh please don’t say I forgot to say the earth has turned the corner. Yes, you have been forgetting a lot of things lately. Lets see.
Just stand over there and don’t move dave. Positive feedbacks. Oh yes. Dec. 9th Climate Crocks.
Christopher Arcus Says:
December 10, 2013 at 8:06 am 2 0 Rate This
Where is the evidence of a global feedback multiplier? Ok, so if there were no feedback multiplier, there would be no positive feedback, right? A positive feedback might be like the ice melting and more sun hits darker earth, but we do not need to argue that. Because you are asking where is the evidence of a positive feedback. Well without positive feedback,there would be no sudden shifts in temperature, particularly positive ones. Looking at the geologic record there is nothing but record of drastic sudden changes in upward temperature.
http://en.wikipedia.org/wiki/File:EPICA_temperature_plot.svg
Deja vu? Oh yeah. You don’t get deja vu. Its always the first time. Gotta go. Watching a movie called Memento. Ever seen it before?
“Deja vu? Oh yeah. You don’t get deja vu”.
I get it, just like Yogi Berra got it when he said “It’s like deja vu all over again”
Oh…and I forgot to mention, the Earth has turned the temperature corner. We are now on our way to a cooling Earth. Houston…that is a problem.
Some of you have suggested that we humans has delayed a transition to cooling. That may be so. But what now?
Jennifer Francis puts up a very convincing case for her research and if she is right (and she has my vote) then> of all the outcomes from climate change, the loss of Arctic ice would have the fastest effect on our lives . A bad tear for ice and the weather changes. The extremes of weather would have a disastrous result on farming and food production and we are not prepared for that.
Jennifer Francis puts up a very convincing case for her research and if she is right (and she has my vote) then> of all the outcomes from climate change, the loss of Arctic ice would have the fastest effect on our lives . A bad year for ice and the weather changes. The extremes of weather would have a disastrous result on farming and food production and we are not prepared for that.
OK…but the Earth is now cooling. Even as it was warming coming out of the Little Ice Age, now it is cooling.
We would have been cooling if we had not pumped so much CO2 into the atmosphere. http://globalwarmingsimplified.weebly.com/ Where we go from here we have a fair idea such as 2-3C temperature rise and 10 meters sea level rise but what is still open is how long it will take.
OK…Let me try again.
Yes there are positive feedbacks and yes there are negative feedbacks.
And yes there are positive feedbacks that could (speculated) cause CO2 to skyrocket (such as thawing tundra).
But I’m asking about a very specific and very important feedback that is crucial to the projections of the Models (and hardwired into all of them).
The Models assume that if nothing else changes, a doubling od CO2 (no matter how it comes about) will cause ~1C increase in temperature. Pretty much everyone on both sides of the argument agree that this should be so. There is no direct evidence of it but the thinking makes sense to both sides.
Now here’s the rub. The Models assume that a 1C temp rise will cause atmospheric water vapor to go up (makes sense). And then the IR absorption of the enhanced atmospheric water vapor will cause further warming (positive feedback). The net of this interplay will be a total 2.5-5 degree C increase in temp. That’s what the Models predict.
But there is no empirical evidence of this feedback. None. Both sides agree to the 1C rise for a doubling of CO2. Both sides agree that 1C temp rise should incite more water vapor. Both sides agree that water vapor is a yet more powerful GHG than CO2. The issue is: what becomes of this water vapor? If it remains as a gas in the atmosphere it should incite more heating as in the Models. But no one knows how it might impact cloud formation. That’s the rub. And a 2% change in cloud cover is a BFD in either direction.
After 20+ years and countless dollars spent, there is no evidence that this is how the system works. Spenser and Lindzen have both put forth analysis that suggest (subject to interpretation) that the net of the increased water vapor is a negative feedback through enhanced cloud formation. And they have been dually challenged. And they may be wrong. But there simply is no study that I know of that shows that the enhanced vapor remains gaseous so as to perform as in the Models.
The Spencer/Linszen studies suggest that the net of a doubling of CO2 will be ~0.5 degree C. They might be wrong. But 0.5C comports better with current observations than what is coming from the Models.
This issue IS the crux of the whole matter.
Meanwhile, the Earth seems to have turned the temp corner (naturally) and we are on our way to a cooling Earth. If so, that IS a problem.
Notice you do not criticise the $13.25 Billion dollars spent on chasing the Higgs Bosun particle in the LHC project, you just complain about Earth Science research like a typical denier. We have around 50,000 years before the next glacial period, and assuming we conquer AGW and get our energy balance budget restored , we will just have to cope with nature’s natural variations and fluctuations – like pre industrial times. Hopefully the Yellowstone National Park super volcano will stay mellow in the remaining interglacial period and we will avoid large asteroid collisions.
http://www.bbc.co.uk/news/science-environment-25312674