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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So where would this might go? Do they have it as a depression?
Where did you live and where are you now?
I'm about 70 miles east of Pensacola.
12Z UKMET...
\
yes still watching ex ericka might have one more trick for us lol
I don't see you on here as much this year. You must be working?
Quoting 7544:
cant wait to move back lol
Where did you live and where are you now?
biloxi by treasure casino bay hy 90
now in fla broward
biloxi ice
You should see the cloud circulation !!
like what?
You click this Link. Bring any model up and where it has the name of the model, like cmc, in the toolbar, delete it and insert ukm there.
http://moe.met.fsu.edu/cgi-bin/cmctc2.cgi?time=2009090512&field=Sea Level Pressure&hour=Animation
Delete the cmc in the above link and insert ukm
I had to provide an afternoon update on the tropics regarding Ex-Erika, 95L and possible 96L.
here
thanks
Good Afternoon, 456.
CLIPER is a statistical track prediction model based on climatology and persistence. It consists of a set of equations that separately predict future zonal (east-west) and meridional (north-south) movements of a tropical cyclone at 12-hr intervals out to 72 hrs. Equations were developed in 2001 to extend the CLIPER forecasts to Day 5 (120 hours) in preparation for the release of official forecasts out to Day 5 in 2003. The predictors include the current and previous 12-hr position, the current and 12-hr previous storm motion, the day of the year, and the maximum surface wind. The initial motion of the storm (persistence) is the most important predictor for this model.
The original CLIPER equations were developed based on historical storm track data for all storms in the North Atlantic Ocean, Carribean Sea and Gulf of Mexico that persisted for at least five days during the period 1931-1970.
Afternoon
I've been really busy with real life stuff this year. I try to pop in though when I can and see how things are going. I also sometimes just watch the tropics and just lurk on the blog to keep some sanity.
I agree on that but if you take a look at the local radar it's building up. I love in Naples Florida and we have had hail so far.
Its nothing.
Just some afternoon thunderstorms.
I hear ya! LOL.
stay away fred grace and whatever else cones down 95
AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1008 AM EDT SAT SEP 5 2009
.DISCUSSION...
A COMPLEX MID AND UPPER LEVEL PATTERN IS EVIDENT IN THE SOUTHEAST
UNITED STATES...GULF OF MEXICO...THE WESTERN NORTH ATLANTIC AND
CARIBBEAN SEA. THIS IS WELL SHOWN ON WATER VAPOR IMAGERY WITH AN
UNUSUALLY DEEP UPPER LEVEL TROUGH REACHING INTO THE SOUTHEAST GULF
OF MEXICO AND THE EXTREME NORTHWEST CARIBBEAN SEA. AHEAD OF THE
TROUGH AXIS...UPPER LEVEL DIFFLUENCE IS WELL APPARENT OVER SOUTH
FLORIDA AND THE KEYS. LOOKING TO THE EAST...A WELL DEFINED MID AND
UPPER LEVEL GYRE CENTERED WELL NORTH OF PUERTO RICO...IS CHURNING
WESTWARD. SURFACE WISE...OUR REGION LIES BETWEEN A MID LATITUDE
TROUGH DRAPED ACROSS NORTH CENTRAL FLORIDA AND THE ADJACENT ATLANTIC
AND GULF WATERS...WITH A SPLINTERED TROPICAL WAVE NORTH AND SOUTH OF
EASTERN HISPANIOLA. BETWEEN THESE TWO FEATURES...A WEAK WESTERN
ATLANTIC RIDGE EXTENDS ACROSS SOUTH FLORIDA. ACROSS THE MARINE
DISTRICT...C-MAN STATION PLATFORM OBSERVATIONS INDICATE MAINLY
SOUTHEAST WINDS NEAR 10 KNOTS OUTSIDE OF DEEP CONVECTION.
OTHERWISE...OUR MORNING SOUNDING WAS PARTIALLY RAIN
CONTAMINATED...BUT A WEAKLY SHEARED...EXTREMELY UNSTABLE AND VERY
MOIST AIRMASS (PWAT > 2.0 INCHES) IS IN PLACE.
Have you ever thrown several marbles down a pipe; well that is what the the tropics will be doing over the next 1-2 weeks. I strong frontal trough developing across the central North Atlantic will cause the high pressure ridge to split and create a pronounce weakness. This is backed by water vapor imagery, steering charts and the other global models.
Below shows the marbles rolling down the pipe
Thanks Ike, do you have a link to that?
I agree.. we've had just enough rain to keep us in the "green" zone on the drought map but not enough to put us in the "blue" zone.. too much rain.
We have gotten alot of use from our pool this summer.
Link
lol, simple atmospheric and fluid dynamics, mass tends to follow the path of least resistance.
trying to lurk a little during lunch break.
I am at work in Weston (Broward County).. and we have a nasty nasty nasty thunderstorm out there that is coming up from the SW...
you can see it on radar.
part of that big blob.
been reading back alittle as I can... is this thing something to watch? Goodness I hope not.
what you are all talking about a storm in the GOM this next week? Where did that come from?
I thought high shear would blow anything out of there???
I need answers! LOL :o)
will check back as I can to try and figure out what is going on.
Thanks and Happy Saturday to those of you not working today.
Gams
It's like 6-8 days out. I wouldn't put much faith in models that far out....yet. Something to watch for now.
Sounds like nothing will get close to the antilles or the CONUS. =P
Other wave
It could if it starts closer to home. Looks like what the CMC and NOGAPS are showing is comparable to Claudette.
I pattern seems to last through mid-September. However, i cannot fully say if it will continue for the last 2 weeks of September.
Viewing: 1951 - 2001
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