Arctic temperatures the warmest in 2,000 years; 2009 Arctic sea ice loss 3rd highest
It's time to take a bit of a break from coverage of the Atlantic hurricane season of 2009, and report on some important climate news. The past decade was the warmest decade in the Arctic for the past 2,000 years, according to a study called "Recent Warming Reverses Long-Term Arctic Cooling" published today in the journal Science. Furthermore, four of the five warmest decades in the past 2,000 years occurred between 1950 - 2000, despite the fact that summertime solar radiation in the Arctic has been steadily declining for the past 2,000 years. Previous efforts to reconstruct past climate in the Arctic extended back only 400 years, so the new study--which used lake sediments, glacier ice cores, and tree rings to look at past climate back to the time of Christ, decade by decade-- is a major new milestone in our understanding of the Arctic climate. The researchers found that Arctic temperatures steadily declined between 1 A.D. and 1900 A.D., as would be expected due to a 26,000-year cycle in Earth's orbit that brought less summer sunshine to the North Pole. Earth is now about 620,000 miles (1 million km) farther from the Sun in the Arctic summer than it was 2000 years ago. However, temperatures in the Arctic began to rise around the year 1900, and are now 1.4°C (2.5°F) warmer than they should be, based on the amount of sunlight that is currently falling in the Arctic in summer. "If it hadn't been for the increase in human-produced greenhouse gases, summer temperatures in the Arctic should have cooled gradually over the last century," Bette Otto-Bliesner, a co-author from the National Center for Atmospheric Research, said in a statement.
The Arctic melt season of 2009
Arctic sea ice suffered another summer of significant melting in 2009, with August ice extent the third lowest on record, according to the National Snow and Ice Data Center. August ice extent was 19% below the 1979 - 2000 average, and only 2007 and 2008 saw more melting of Arctic sea ice. We've now had two straight years in the Arctic without a new record minimum in sea ice. However, this does not mean that the Arctic sea ice is recovering. The reduced melting in 2009 compared to 2007 and 2008 primarily resulted from a different atmospheric circulation pattern this summer. This pattern generated winds that transported ice toward the Siberian coast and discouraged export of ice out of the Arctic Ocean. The previous two summers, the prevailing wind pattern acted to transport more ice out of the Arctic through Fram Strait, along the east side of Greenland. At last December's meeting of the American Geophysical Union, the world's largest scientific conference on climate change, J.E. Kay of the National Center for Atmospheric Research showed that Arctic surface pressure in the summer of 2007 was the fourth highest since 1948, and cloud cover at Barrow, Alaska was the sixth lowest. This suggests that once every 10 - 20 years a "perfect storm" of weather conditions highly favorable for ice loss invades the Arctic. The last two times such conditions existed was 1977 and 1987, and it may be another ten or so years before weather conditions align properly to set a new record minimum.
The Northeast Passage opens
As a result of this summer's melting, the Northeast Passage, a notoriously ice-choked sea route along the northern Russia, is now clear of ice and open for navigation. Satellite analyses by the University of Illinois Polar Research Group and the National Snow and Ice Data Center show that the last remaining ice blockage along the north coast of Russia melted in late August, allowing navigation from Europe to Alaska in ice-free waters. Mariners have been attempting to sail the Northeast Passage since 1553, and it wasn't until the record-breaking Arctic sea-ice melt year of 2005 that the Northeast Passage opened for ice-free navigation for the first time in recorded history. The fabled Northwest Passage through the Arctic waters of Canada has remained closed this summer, however. An atmospheric pressure pattern set up in late July that created winds that pushed old, thick ice into several of the channels of the Northwest Passage. Recent research by Stephen Howell at the University of Waterloo in Canada shows that whether the Northwest Passage clears depends less on how much melt occurs, and more on whether multi-year sea ice is pushed into the channels. Counter-intuitively, as the ice cover thins, ice may flow more easily into the channels, preventing the Northwest Passage from regularly opening in coming decades, if the prevailing winds set up to blow ice into the channels of the Passage. The Northwest Passage opened for the first time in recorded history in 2007, and again in 2008. Mariners have been attempting to find a route through the Northwest Passage since 1497.
Figure 1. Sea ice extent on September 2, 2009, with the Northwest Passage (red line) and Northeast Passage (green line) shown. The Northeast Passage was open, but the Northwest Passage was blocked in three places. The orange line shows the median edge of sea ice extent for September 2 during the period 1979 - 2000, and this year's ice extent is about 19% below average. Image credit: National Snow and Ice Data Center.
Commercial shipping begins in the Northeast Passage
This year's opening marks the fourth time in five years that the Northeast Passage has opened, and commercial shipping companies are taking note. Two German ships set off on August 21 on the first commercial voyage ever made through the Northeast Passage without the help of icebreakers. The Northeast Passage trims 4,500 miles off the 12,500 mile trip through the Suez Canal, yielding considerable savings in fuel. The voyage was not possible last year, because Russia had not yet worked out a permitting process. With Arctic sea ice expected to continue to decline in the coming decades, shipping traffic through the Northeast Passage will likely become commonplace most summers.
When was the Northeast Passage ice-free in the past?
People have been attempting to penetrate the ice-bound Northeast Passage since 1553, when British explorer Sir Hugh Willoughby attempted the passage with three ships and 62 men. The frozen bodies of Sir Hugh and his men were found a year later, after they failed to make it past the northern coast of Finland. British explorer Henry Hudson, who died in 1611 trying to find a route through Canada's fabled Northwest Passage, (and whom Canada's Hudson Bay and New York's Hudson River are named after), attempted to sail the Northeast Passage in 1607 and 1608, and failed. The Northeast Passage has remained closed to navigation, except via assist by icebreakers, from 1553 to 2005. The results published in Science today suggest that prior to 2005, the last previous opening was the period 5,000 - 7,000 years ago, when the Earth's orbital variations brought more sunlight to the Arctic in summer than at present. It is possible we'll know better soon. A new technique that examines organic compounds left behind in Arctic sediments by diatoms that live in sea ice give hope that a detailed record of sea ice extent extending back to the end of the Ice Age 12,000 years ago may be possible (Belt et al., 2007). The researchers are studying sediments along the Northwest Passage in hopes of being able to determine when the Passage was last open.
References
Belt, S.T., G. Masse, S.J. Rowland, M. Poulin, C. Michel, and B. LeBlanc, "A novel chemical fossil of palaeo sea ice: IP25", Organic Geochemistry, Volume 38, Issue 1, January 2007, Pages 16-27.
Darrell S. Kaufman, David P. Schneider, Nicholas P. McKay, Caspar M. Ammann, Raymond S. Bradley, Keith R. Briffa, Gifford H. Miller, Bette L. Otto-Bliesner, Jonathan T. Overpeck, Bo M. Vinther, and Arctic Lakes 2k Project Members, 2009, "Recent Warming Reverses Long-Term Arctic Cooling", Science 4 September 2009: 1236-1239.
Howell, S. E. L., C. R. Duguay, and T. Markus. 2009. Sea ice conditions and melt season duration variability within the Canadian Arctic Archipelago: 1979.2008, Geophys. Res. Lett., 36, L10502, doi:10.1029/2009GL037681.
Tropical Weather Outlook
The remains of Tropical Storm Erika are bringing heavy rain to Puerto Rico and the Virgin Islands today, and this activity will spread to the Dominican Republic on Saturday. Radar-estimated rainfall shows up to three inches of rain has fallen in eastern Puerto Rico from the storm. Long range radar out of Puerto Rico shows no surface circulation or organization of the echoes, and redevelopment of Erika over the next three days is unlikely to occur due to high wind shear of 25 - 30 knots. By Monday or Tuesday, shear may drop enough to allow redevelopment, depending upon the location of Erika's remains. Redevelopment is more likely if Erika works its way northwestward into the Bahamas.
A large tropical wave with plenty of spin is located a few hundred miles southwest of the Cape Verdes Islands, off the coast of Africa. Heavy thunderstorm activity has increased slightly in this wave over the past day, and it has the potential to gradually develop into a tropical depression by early next week. NHC is giving this wave a low (less than 30% chance) of developing into a tropical depression by Sunday. The GFS model continues to predict development of this wave into a tropical depression early next week.
I'll have an update Saturday or Sunday, depending upon developments in the tropics.
Jeff Masters
Reader Comments
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I wouldn't say the USA is safe the rest of 2009. Even I'm not that stupid...I hope.
Morning, CRS. We've clear skies so far this morning in Nassau.
Morning Baha, It was squally for about an hour, I came to computer to look at satellite image after closing windows. Looks like it was an isolated thunderstorm. Bar is holding high so far.
CRS
95 is going to die
duh
there will be nothing
this season is over
LOL!! Good glad to hear it!!
Just trying to get a little (social) therapy in on a beautiful Sat. morning. I don't know much about the weather but Storm W, Drakster, Ike, and many others are helping me learn.
I learn REAL FAST but have problems dealing with social issues. Not the handle name.
Did not mean to offend!
500mb anomalies
Wind shear anomalies
none taken, I'm that much into the topic.
nice to see the blog back to normal, lets hope it stays that way..
btw, looked up wind shear on google, no need to answer my question..
Just ask MichaelSTL...
GW brings too much drama here.
yea we use to had some intense debates on the subject.
AL 95 2009090512 BEST 0 159N 299W 25 1008 DBAL 95 2009090512 BEST 0 160N 299W 25 1008 DB
They change their mind fast (15.9 to 16.0)
Amen. I stay out of it.
Storm - Carolinians have much the same feelings as Floridians, these days. :D
Regarding GW/CC - Lots of data pointing both ways as to where we are right now, and it is obvious that the planetary climate changes a lot throughout history. Seems to me that the current 'discussion' comes down to whether a participant thinks that humankind is capable of / guilty of being a large enough force on the planet to be able to affect planetary climate.
What surprises me is that there are all these 'fixes' proposed for man-created GW/CC, but nobody addresses the root issue which is inherently implied by such: there are just too many people, and they are making more all the time.
In an illness or disease, you don't treat the *symptoms*, you treat the *cause*. I'm not saying we should kill off lots of people :), But I do think that the brainpower devoted to changing atmospheric carbon dioxide levels would be better used addressing the issue of overpopulation and intelligent, informed reproduction.
Food for thought!
Great book to read, here between weather alerts, one that will likely give you a viewpoint you never experienced before: "Ishmael", by Daniel Quinn.
RIP 2009
95 is dead
put a sock in it
ignore him and he will leave
dont see any of his posts..hmmmmm, oh yeah i know why..duh..LOL
What's up with the GOM potential?
Actually the models dont look like they develop 95L but, do develop the wave that will be approaching and rolling off Africa!
40W and east is where it isn't subsidence. Look at 1667 for the image closer to Africa.
According to New Orleans...
MARINE...
LIGHT TO OCCASIONALLY MODERATE SOUTHEASTERLY FLOW WILL PREVAIL
THROUGH THE WEEKEND. A WEAK AREA OF LOW PRESSURE IS FORECAST TO
DEVELOP ALONG AN OLD TROUGH OVER THE GULF AND TRACK TOWARD THE
LOUISIANA COAST LATE SUNDAY INTO MONDAY. THERE IS STILL SOME
UNCERTAINTY AS TO EXACTLY WHERE ALONG THE LOUISIANA COAST THIS
FEATURE WILL ACTUALLY MOVE INTO WITH MODELS OFFERING VARIOUS SOLUTIONS
..BUT AT THIS TIME WE ARE FORECASTING THE LOW TO MOVE INTO THE
SOUTHEAST LOUISIANA COASTAL WATERS WEST OF THE MISSISSIPPI RIVER AND
THEN INLAND AT THE BEGINNING OF THE WEEK. THIS FEATURE MAY CAUSE
WINDS TO INCREASE A BIT WITH CORRESPONDINGLY HIGHER SEAS.
very true. Ships and other reliable models show shear increasing over 95L but the ECMWF blows up the wave behind.
Luckily, it lines up perfectly with the pronounce weakness so this 1 seems fish
not one of the models I look to, but as we say here - "Every dump pan has it cover"
How many times do you have to explain this?
Thanks StormW, just catching up on some of the other discussions and it is referenced
From crownweather trop discussion yesterday -
"The final item I want to mention is the fact that some of the computer forecast guidance is hinting at one to two trough splits over the next week or so in the Gulf of Mexico. Wind shear values in the Gulf of Mexico are unfavorable for development and are forecast to remain unfavorable for at least the next 3 to 4 days. It was interesting to note that the latest European model (12Z) shows some sort of low pressure development towards later next week in the northern Gulf of Mexico. With forecasted high pressure over New England, this would be a possible scenario of a homegrown system forming at the end of a trough split in the northern Gulf of Mexico. It is something to keep in the back of your mind, but for now it is a remote possibility"
Then has the developing wave basically go up before even hitting 40W. Straight up. Doesn't happen too often.
Hopefully make for nice weather. Right now, it is cool and wet... once again.
As for the LBar... "even a blind squirrel finds a nut now and then"?
Yep confusing is right. At the same time the ECMWF is predicting a negative NAO they are recurving or dropping the storms off Africa. And the one Tampa mentioned behind these two. The Euro just has it sitting and spinning. Weird year. Lol.
Reported.
Thanks Storm
Nice looking wave to emerge later today at a southern latitude.
As has been said.. towards the end of the month things could get interesting again.
CFS has it weaker (as it always does though showing deep subsidence right now) but still shows something coming in early October.
I like that name.. it sounds friendly.. unlike some of the choices they have had in the past.
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