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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lol
:O
look at the shear map someone posted. No shear in the SW carrib
no shear over SW carribean convection
I created that map for my September outlook back on 31 August
Go here for current shear maps
hey we did get some rain and cool down and thankfully no flooding.
.
I believe that this is the first time we've seen an orange special feature. All before have been red.
I looked at your shear map ...are those orangish lines high shear ..I think that they have a number 40 near them. Is that what would inhibit any movement into the GOM?
eventually it will curve out to sea, but depending on its intensity it may do so further west/east.
There is a massive cyclone developing over the Central North Atlantic in about 4-7 days that will create a weakness that appears to extend to the shallow layers.
The same is true for the wave behind 95L that the models appear more interested in.
So weather do you forsee any major troughness continuing for this month. I admit im a little concerned at these paths of the cv storms have been takeing. A little to close to SC for comfort. If it werent for these troughs I think the risk of getting hit is higher this year than normal.
Tropical Cyclone Formation Alert (0030z 05SEPT)
==============================================
An area of convection (97B) located at 20.4N 87.8E or 125 NM south-southwest of Kolkata, India. Recent animated infrared satellite imagery shows deep convection persisting near the center of a low level circulation center evident in recent microwave satellite imagery. This disturbance is moving into an area of decreased vertical wind shear and favorable poleward and equatorward outflow associated with ridging aloft. Recent observations from reporting stations along the northeastern Indian coast, near the center of low pressure, indicates surface pressures ranging from 994 to 996 MB.
Maximum sustained winds near the center is 27-32 knots with a minimum sea level pressure of 995 MB. Based on good low level signature, low estimated central surface pressure, and inproving upper level support, the potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is UPGRADED TO GOOD.
that was the wind shear map that 456 posted and it has a date of SEP 15th on he was showing some things with me on it about the wind shear oh and yes theres 20 to 40kt of wind shear right now
those units are meters per second with the threshold being about 8-10 m/s. Does not entirely protect the GOM from storms like Claudette which developed in the GOM. This was the general pattern for the past three months and its the weakest the TUTT appears and patterns can briefly break. so the answer to you is that any shear from the TUTT only slows down development until a feature manages to enter the GOM.
It appears it will continue...read the piece under steering
I was just about to post it but the future of 95L does not look good. Much of the intensity guidance show shear increasing across 95L to 30 knots. Neither the ECMWF nor GFS develops the feature. Some development is expected in the near term but the long-term faith of 95L is uncertain.
One thing I've notice is that the models show 95L moving NW as it develops but then encounter shear near 20N if this does play out then likely it will not pass a moderate TS. However the other solution is that the storm does not develop and track west in shallow steering flow apparently missing some of the heavier shear.
*
Date/Time Issued*: September 05, 2009 0110 UTC*
Product(s) or Data Impacted: *Scatterometer data
*
Date/Time of Initial Impact: *September 03, 2009 2010 UTC*
Date/Time of Expected End: *Until Further Notice*
Length of Event: *Until further notice
*
Impacts on Users and Significance: *Users will not receive Quikscat
data.
*
User Actions: *None.*
Details/Specifics of Change:
Recovery of the instrument this morning and had unexpected
results. We've been analyzing data, and will pick up the recovery
first
thing in the morning. We are hopeful that we will have good SCI
data back
on line by the end of the day tomorrow.
http://www.ssd.noaa.gov/PS/SATS/SPBULL
/MSG2480114.01.txt
...unexpected results ...analyzing data
been there myself too many times!
Stay tuned
(I still blame Erika for causing quikscat to say "sheesh I give up")
Sorry for the family of that poor guy. Those bull sharks are really aggressive. I don't mess with them at all, I have been literally ran out of the water by a 9' bull while diving whelks and I have heard so many stories that I just don't trust them at all. The minute I see them in the water I just leave, I don't push it, just not worth it... now if you don't see him coming then you really don't stand a chance. What a way to go....
What are your comments on the Invest 97B close to India...looks like it will run into land before it has a chance to turn into a tropical cyclone...
I'm not expecting development in that area during the time frame on the image but lets say something did, look at the ridging to the north....
Sorry but I cant help you with that 1, havent been watching it but I will dig up some info on it and email u.
I do track cyclones world wide but my attention is drawn to the atl and eastern pacific at a time like this.
What's the steering like though?
After that shocking incident I'm staying out of the water for now despite the location it happened - the Atlantic side of the island which has taken numerous lives.
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