Arctic temperatures the warmest in 2,000 years; 2009 Arctic sea ice loss 3rd highest

By: Dr. Jeff Masters , 2:32 PM GMT on September 04, 2009

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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

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1575. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisories Number ONE
DEPRESSION BOB04-2009
5:30 AM IST September 5 2009
======================================

SUBJECT: Depression Over Northwest Bay Of Bengal

At 0:00 AM UTC, Latest satellite imageries and coastal observations indicate that a depression has formed over northwest Bay of Bengal and lays centered near 20.5N 88.0E or 170 kms southeast of Balasore, 230 kms south of Kolkata.

Satellite imagery indicates gradual organization of convection during past 12 hours. The Dvorak intensity of the system is T1.5. Associated broken intense to very intense convection lies over Bay of Bengal between north of 17.0N and west of 89.0E Orissa and north coastal Andhra Pradesh

3 minute sustained winds near the center is 25 knots with a central pressure of 990 hPa. The state of the sea is rough to very rough around the system's center.

Vertical wind shear of horizontal wind over the region is low to moderate (aroung 10-20 knots). Sea surface temperatures is around 28C. The system is supported by upper level divergence and lower level convergence. Strong easterly winds prevail over the region in the upper tropospheric level as observed at 0:00 AM UTC, The 24 hours pressure fall is higher in the north-northwesterly direction and is maximum (-6.6 hPa) over Digha.

Considering all the above, the system is likely to intensify further and move in a northwesterly direction and cross north Orissa-West Bengal coast between Balasore and Diamond Harbor by later this evening/tonight.
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General question on current warming in Artic.. how much of ice loss can be attribute to man's activities including using ice breakers?
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Quoting serialteg:

Hey Storm, can you go a little into what are those MJO and Nao things? I haven't been able to understand those maps.

I'll take a stab at it...

The NAO (North Atlantic Oscillation) determines the amount of ridging over Greenland. A strongly negative NAO indicates a strong ridge over Greenland. This usually causes patterns upstream to shift into a trough in the east/ridge in the west pattern. Also, this is associated many times with increased pressures in the arctic regions and decreased surfaces pressures over the Tropical Atlantic, meaning a greater possibility of tropical development.

Research has shown that a strongly positive NAO results in the strengthening and shift of the Azores High ot the east, placing it closer to the western side of the Atlantic basin. As the Atlantic hurricanes approach the western periphery of this strong High pressure system, it acts as a conveyer belt causing a hurricane to take a more northerly track, and in some situations, steering it away from the Eastern U.S. On the contrary, a strongly negative NAO results in the weakening and shift to the south and west of the Azores High, placing it closer to the southeastern U.S. This would result in the steering of Atlantic hurricanes more towards the Eastern United States or into the Gulf of Mexico, making it more of a possibility for landfall. I'm not saying that this is always the case. These are just a couple scenarios. Hurricane forecasting is very difficult and there are many different factors that come in to play.

OLR (Outgoing Longwave Radiation) is a measure of the cloudiness and association convection over an area. Negative/low OLR indicates increased convection (decreased sunlight), positive/high OLR indicates more sunlight and less convection. It is most often used in the tropics in conjunction with the MJO (Madden-Julian Oscillation). There are several phases of the MJO which favor different areas of the Tropics to receive anomalously high or low amounts of convection. For example, notice the difference between the Atlantic and the WPAC right now. There is clearly less OLR over the WPAC. Sometime's you'll hear the phrase wet or dry MJO, it's really refering to OLR and the amount of convection induced by a specific phase of the MJO. But most here actually don't know that. Obviously, decreased OLR indicates more vertically ascent and instability, and that helps TC genesis.

adrian


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General question for the the remains of Erika and the Carribean... when I look at the various images it appears there is a very broad area of circulation that circles the Carribean Sea. Is the L associated with Erika in the middle of it somewhere and.. could this very broad circulation develop into anything?
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2AM TWO out:

000
ABNT20 KNHC 050527
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT SAT SEP 5 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

AN AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS LOCATED
ABOUT 275 MILES WEST OF THE SOUTHERNMOST CAPE VERDE ISLANDS. THIS
SYSTEM IS SHOWING SOME SIGNS OF ORGANIZATION
AND HAS THE POTENTIAL
FOR SLOW DEVELOPMENT DURING THE NEXT DAY OR TWO AS IT MOVES WEST OR
WEST-NORTHWESTWARD AT 15 TO 20 MPH. THERE IS A MEDIUM CHANCE...30
TO 50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER AVILA


I guess the cliche "Looks can be deceiving" applies here, if Avila thinks it has potential. Avila is one NHC forecaster who is very blunt, and doesn't sugarcoat.
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1566. JLPR
Quoting Bordonaro:

Thanks for pointing that out, I appreciate that! Next time I'll check out the CIMSS maps first to determine what I'm looking at!


no prob =D
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1565. growe
"Studies" that show the Arctic is the warmest it's been in 2000 years are meaningless rubbish, considering they can't even agree on what the current global temperatures are. This year, for example, centres such as UAH and NCDC have disagreed by as much as 0.6 C on global average temperatures for various months. If 0.6 C doesn't sound like much, remember this is the total amount of warming that is claimed to have happened during the 20th century, and is what all the fuss is about. The fact is that satellite records, the only records worth paying any attention to, go back at most 30 years, which is not long enough to say anything about "climate" as opposed to "weather".

Also, claiming that the fact that the ice melt in 2009 is much less than in the past 2 years is due to different atmospheric circulation patterns is disingenuous. You could equally well say that the larger melts in 2007/8 were due to anomalous winds and/or ocean currents (studies have indeed reported this). The fact is that these factors contribute to ice cover in *every* year, so trying to drag them in only when it's convenient isn't proper science.
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Quoting JLPR:


Upper level low to the west of it?
that's a Low level low

Thanks for pointing that out, I appreciate that! Next time I'll check out the CIMSS maps first to determine what I'm looking at!
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Quoting StormW:


Don't see any evidence as of yet.


What part of the GOM do you live in? I have seen that kind of problem with ants and other critters in south Texas before.
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No tropics near us = no peeps

Looks like ol' Serialteg is left with the remnants of Erika making him company...

Rumble of thunder has never seemed so friendly.
Member Since: August 22, 2006 Posts: 2 Comments: 1983
Okay...gone too. Have to pay attention to this next bit on this PC...see you soon!
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Oh yea I will start working on the ants hahaha

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Ok I'm out for the night you all play nice and thank you all for the info.... Very good reading.....

Taco :0)
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Quoting StormW:


Basically, on the MJO maps, where green is, that represents upward motion, or upward vertical velocity, The stronger the green, the stronger the upward motion. Without upward motion, ya don't get very much lift in the atmosphere, no lift...no clouds. Think of green as "go" On the real time map...brown shows downward motion. On the forecast map, orange and yellow are downward motion. Sinking air. Sinking air dries out the atmosphere, and basically doesn't generate any lift...dry air, no lift = no clouds. You saw how Erika had convection flare up and dissipate? God example.

The negaive NAO implies a weaker A/B ridge, and weaker Icelandic Low, which supposedly displaces the mean trof in the Atlantic further to the north, and not as strong. Had we been in a good negative NAO, we'd have probably seen Bill and Danny both score direct U.S. hits.


Hmm ... Don't weaker ridges mean less chances for poleward movement?
Member Since: August 22, 2006 Posts: 2 Comments: 1983
1553. KEEPEROFTHEGATE (Mod)
18 days away from first day of fall

85 days away from end of 2009 hurricane season
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Quoting StormW:


A decent negative NAO would kinda be 3 fold...wouldn't necessarily warm SST's given the time of year, but may help them maintain somewhat...weaker trades (should allow for weaker shear). Weaker trades also allow for energy to build up. The big trofs we've been seeing could be weaker, farther north.


Interesting...thanks.
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1550. JRRP
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Given the very hostile upper level conditions throughout the Atlantic basin, I really don't expect any tropical cyclone development during the next week. Really seeing the classic effects from El Nino this hurricane season with fast upper level westerlies across the Caribbean and above normal subsidence across the Central Atlantic. Right now, I'm expecting only one more major spike in tropical action from late September to mid October this hurricane season and then rather quiet conditions thereafter as the long-range climate models show a very strong MJO impulse coming into the Western Atlantic come the end of September and into October. But, that remains to be seen.
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Quoting jeffs713:

thats impressive. I cleaned off a friend of mine's desktop, and he was complaining how it was running "crazy slow". 22 different trojans and malware later... (and taking a bunch of crap off it didn't need) it was blazing fast. Of course, it got jammed up again within 3 months.


Yeah, I'm in charge of configuration and acquisition (Long with a great amny other happy tasks). I love it when (and I kid you not) I open the box on a new laptop, throw the company image on it and 5 minutes after I hand it to him it's been infected with Vundo
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1544. KEEPEROFTHEGATE (Mod)
Quoting TexasHurricane:


Is that what it is looking to do and what would that mean?
winters coming
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Quoting StormW:


Downward motion of the MJO is forecast for the last 2 weeks of this month. What is going to be ineteresting, is seeing what happens if we in fact go to a negative NAO in October and November.


Hey Storm, can you go a little into what are those MJO and Nao things? I haven't been able to understand those maps.
Member Since: August 22, 2006 Posts: 2 Comments: 1983
Quoting StormW:


Downward motion of the MJO is forecast for the last 2 weeks of this month. What is going to be ineteresting, is seeing what happens if we in fact go to a negative NAO in October and November.


Is that what it is looking to do and what would that mean?
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1540. Patrap
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Quoting JLPR:


it looks like the low is a fighter xD
and now the very dry air that was in front of it is diminishing


Lol you really need another hobby hehe...

Blob watching!

Dust off that camera and start making art...

I love 35mm darkroom developing
Member Since: August 22, 2006 Posts: 2 Comments: 1983
1536. JLPR


it looks like the low is a fighter xD
and now the very dry air that was in front of it is diminishing
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1535. KEEPEROFTHEGATE (Mod)
not much to look at
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Now that I've vented...conditions are looking ather poor fordevelopment justabout everywhere...shear is high and the MJO is out of the picture til what, the third week in September?
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Quoting KoritheMan:
95L probably won't develop if it tracks northward like the models forecast, as prohibitively strong westerly to southwesterly shear will be in the path for days.

If it stays further south and continues west, then we will likely have a tropical depression in the next few days.


Still there's some strong shear in front of it, and it's already pulsing N as observed in TPW.
Member Since: August 22, 2006 Posts: 2 Comments: 1983
Quoting StormW:


Should begin to slack off some around mid month...probably after these next 2-3 waves roll off Africa.


Really..... so that is about it then? I thought I saw a post earlier of things maybe getting active in late Septmenber and early October. hmmmmm,maybe not.
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1530. JRRP
hurricane

see you tomorrow

Link
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95L probably won't develop if it tracks northward like the models forecast, as prohibitively strong westerly to southwesterly shear will be in the path for days.

If it stays further south and continues west, then we will likely have a tropical depression in the next few days.
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That ITCZ is sure high in latitude this year...
Member Since: August 22, 2006 Posts: 2 Comments: 1983
1526. JLPR
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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