The climate is changing: the Arctic Dipole emerges
The dramatic loss of Arctic sea ice in recent years has created a fundamental new change in the atmospheric circulation in the Northern Hemisphere that has sped up sea ice loss and is affecting fall and winter weather across most of the Northern Hemisphere, according to several recent studies. Arctic sea ice loss peaks in September and October, exposing a large area of open water that heats the air above it. This extra heat has helped drive September - November air temperatures in the Arctic to 1°C (1.8°F) or more above average over about half of the depth of the lower atmosphere (Figure 1). This deep layer of warm air has grown less dense and expanded, pushing the top of the troposphere (the lower atmosphere) higher. The result has been a decrease in the pressure gradient (the difference in pressure) between the North Pole and mid-latitudes. With not as much difference in pressure to try and equalize, the jet stream has slowed down in the Arctic, creating a major change in the atmospheric circulation for the Northern Hemisphere.
Figure 1. Cross section of Arctic temperature anomaly from 1000 mb (the surface) to 300 mb (roughly, the height of the top of the lower atmosphere or troposphere). Cross section is taken along the Date Line (180°W), from 60°N latitude (left side) to the North Pole (right side), for September - November for the 12-year period 1998 - 2009. Three year averages were done to reduce the amount of year-to-year noise associated with natural variation. Other cross sections along different lines of longitude show similar results, though typically with more warming aloft and less warming at the surface. Image credit: NOAA/ESRL.
A new atmospheric pattern emerges: the Arctic Dipole
In a 2008 article titled, Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system Zhang et al. show that the extreme loss of Arctic sea ice since 2001 has been accompanied by a radical shift of the Arctic atmospheric circulation patterns, into a new mode they call the Arctic Rapid change Pattern. The new atmospheric circulation pattern has also been recognized by other researchers, who refer to it as the Arctic Dipole (Richter-Menge et al., 2009). The old atmospheric patterns that controlled Arctic weather--the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), which featured air flow that tended to circle the pole, now alternate with the new Arctic Dipole pattern. The Arctic Dipole pattern features anomalous high pressure on the North American side of the Arctic, and low pressure on the Eurasian side. This results in winds blowing more from south to north, increasing transport of heat into the central Arctic Ocean. The Arctic Dipole pattern occurred in all summer months of 2007 and helped support the record 2007 summer reduction in sea ice extent (Overland et al., 2008). Overland et al., 2010 also found that the Arctic Dipole pattern tended to create an increase in easterly winds in the lower half of the atmosphere of 40% in fall, between 2002 - 2008. Fall 2008 through spring 2009 featured the old AO pattern. The new Arctic Dipole pattern re-appeared in June - July 2009, but the old AO pattern dominated in August - September, resulting in greater sea ice extent than in 2007 and 2008. The Arctic Dipole pattern was active again in October, inactive in November, and reasserted itself this December. As a result, Arctic sea ice reached a new record minimum for a 10-day period in early November, increased above record lows during late November and early December, and appears poised again to reach a new record minimum later this December (Figure 2).
Figure 2. Sea ice extent in the Arctic for this year (blue line) compared to the record low year of 2007 (green line) and 1979 - 2000 average (gray line). One could make the ice loss looks less significant by using the full satellite data record from 1979 - 2008 for the average. Image credit: National Snow and Ice Data Center.
Arctic Dipole blamed for colder winters in East Asia
It turns out that the new Arctic circulation patterns help to intensify the Siberian High, a large semi-permanent region of surface high pressure prevalent in winter over Siberia. According to Honda et al. (2009), this results in increased flow of cold air out of the Arctic in early winter over eastern Russia, Japan, Korea, and eastern China, causing colder temperatures. By late winter, the pattern shifts, resulting in colder than average temperatures from East Asia to Europe.
Arctic Dipole blamed for drier winters in Northern Europe
Francis et al. (2009) found that during 1979 - 2006, years that had unusually low summertime Arctic sea had a 10 - 20% reduction in the temperature difference between the Equator and North Pole. This resulted in a weaker jet stream with slower winds that lasted a full six months, through fall and winter. The weaker jet caused a weaker Aleutian Low and Icelandic Low during the winter, resulting in a more negative North Atlantic Oscillation--a pattern that usually brings reduced winter precipitation over Alaska and Northern Europe and increased precipitation over Southern Europe. A more negative NAO also tends to bring cold winters to eastern North America and Europe. Though it was not mentioned in the article, reduced Arctic sea ice may also cause dry early winter conditions in the U.S. and the Caribbean (Figure 3). The authors noted that strong La Niña or El Niño events can have a much larger influence on the wintertime atmospheric circulation, which will overshadow the changes due to Arctic sea ice loss.
Figure 3. Difference in early winter precipitation (November - January) between five years that had low Arctic sea ice (2005, 2006, 2007, 2008, and 2009), and five years that had unusually high Arctic sea ice extent (1981, 1984, 1986, 1989, 1993). Note that low sea ice may be responsible for dry conditions in early winter for the Caribbean and most of the U.S.
Commentary
Arctic sea ice loss appears to have created a new atmospheric circulation pattern that brings more warm air in the Arctic, creating a positive feedback loop that causes even more sea ice loss. This feedback loop increases the likelihood that an ice-free Arctic in the summer will indeed come by 2030, as many Arctic experts are predicting. It's worth noting that such an atmospheric circulation shift was not predicted by the climate models. Indeed, the loss of Arctic sea ice over the past three years exceeds what any of our models were predicting (Figure 4). While we can rightly criticize these models for their inaccuracy, we should realize that they are just as capable of making errors not in our favor as they are of making errors in our favor.
Figure 4. Arctic sea ice extent from observations (thick orange line) and 13 model forecasts used to formulate the 2007 IPCC report (light lines). The thick black line is the multi-model ensemble mean, with the standard deviation plotted as a dashed black line. Image has been updated to include the observed 2008 and 2009 measurements. None of the models predicted the record 2007 sea ice loss. Image credit: Arctic sea ice decline: Faster than forecast by Stroeve et al., 2007.
References
Francis, J.A., W. Chan, D.J. Leathers, J.R. Miller, and D.E. Veron, 2009, "Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent", Geophysical Research Letters, 36, L07503, doi:10.1029/2009GL037274.
Honda, M., J. Inoue, and S. Yamane, 2009. Influence of low Arctic sea - ice minima on anomalously cold Eurasian winters, Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.
Overland, J. E., M. Wang, and S. Salo, 2008: The recent Arctic warm period, Tellus, 60A, 589.597.
Overland, J. E., and M. Wang, 2010: Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice. Tellus, 62A, 1–9.
Richter-Menge, J., and J.E. Overland, Eds., 2009: Arctic Report Card 2009, http://www.arctic.noaa.gov/reportcard.
Simmonds, I., and K. Keay (2009), Extraordinary September Arctic sea ice reductions and their relationships with storm behavior over 1979.2008, Geophys. Res. Lett., 36, L19715, doi:10.1029/2009GL039810.
Wu, B., J. Wang, and J. E. Walsh, 2006: Dipole anomaly in the winter Arctic atmosphere and its association with sea ice motion. J. Climate, 19, 210-225.
Zhang, X., A. Sorteberg, J. Zhang, R. Gerdes, and J. C. Comiso (2008), Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system, Geophys. Res. Lett., 35, L22701, doi:10.1029/2008GL035607.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 — Blog Index
http://www.bloomberg.com/apps/news?pid=20601109&sid=aBYSp0.XfXZs&pos=14
I'm thinking training not what we need!
Excerpt from Review from TPC:
2009 Atlantic Season Climatology
9 named storms, 3 of which became hurricanes, including 2 major hurricanes (Bill and Fred)
Below the long-term averages of 11 named storm and 6 hurricanes
Average number of major hurricanes
Two additional tropical depressions
The Accumulated Cyclone Energy (ACE) index for the season was 58% of the long-term median
Latest formation of a tropical storm since the 1983 season (TS Ana – 12 Aug, MH Alicia – 15 Aug)
Claudette and Ida brought tropical-storm-force winds to the U.S.
Fred became strongest hurricane on record so far south and east in the Atlantic
Grace formed farther northeast in the Atlantic than any other tropical storm on record
Ida was the first November hurricane in the Gulf of Mexico since Hurricane Kate (1985)
NHC’s Wish List for 2010
Modified initialization for GFDL & HWRF to account for new GFS (much progress already made for GFDL; initialization changes might not be sufficient for HWRF)
Additional modifications to GFDL & HWRF, if necessary, for next 2 phases of GFS (also potential schedule crunch?)
Capability to run 5 GFDL/HWRFs per synoptic cycle for Atlantic, eastern and central Pacific basins combined
Parallel testing of physics modifications in HWRF
Parallel testing of assimilation of TC inner core data in HWRF (NHC believes these latter two items should have higher priority than ocean coupling)
+ 2.5
Mobile has new warnings as well
Taco :0)
I have a final early in the morning and im terrified I wont be able to get out. We have water all around the house and pouring onto the driveway.
Yes I do especially if the ECMWF pans out.
NEXRAD Radar
New Orleans, Storm Relative Mean Radial Velocity 1.45 Degree Elevation Range 124 NMI
You should be buying Louisiana/Texas rice, anyway...
;-)
Sorry I forgot to add this information...... Thanks Pat
Taco :0)
Ok, that I see. Thought someone reported waterspout by eyeball...the Lake would be an unfortunate place to be.
920
WGUS54 KLIX 150057
FFWLIX
LAC051-057-071-075-087-089-150215-
/O.NEW.KLIX.FF.W.0047.091215T0057Z-091215T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
657 PM CST MON DEC 14 2009
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
* FLASH FLOOD WARNING FOR...
JEFFERSON PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITIES OF...METAIRIE...MARRERO...HARVEY...
GRETNA...AVONDALE...
EAST CENTRAL LAFOURCHE PARISH IN SOUTHEAST LOUISIANA...
ORLEANS PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITIES OF...NEW ORLEANS...EAST NEW ORLEANS...
NORTHWESTERN PLAQUEMINES PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITY OF BELLE CHASSE...
SOUTHWESTERN ST. BERNARD PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITY OF CHALMETTE...
SOUTHEASTERN ST. CHARLES PARISH IN SOUTHEAST LOUISIANA...
* UNTIL 815 PM CST
* AT 650 PM CST...AN AREA OF STRONG THUNDERSTORMS PRODUCING HEAVY
RAINFALL IS MOVING ACROSS THE METRO NEW ORLEANS AREA. EXPECTED
RAINFALL OF 1 TO 2 INCHES WITHIN THE NEXT TWO HOURS WILL LIKELY
ACCOMPANY THE SHOWERS AND THUNDERSTORMS. HEAVY RAINFALL FALLING ON
SATURATED SOIL MAY PRDUCE FLASH FLOODING.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.
Thank you Drak.
Ever hear of Salt Lake City? Mighty big salt lake there.
Your right on that gordy,..and maybe that Artic Air Mass is gonna meet that stream one day soon,and well..Thats all Im gonna say fer now
For a better idea of how the separation of fresh water and salt water works, look up how the Dutch do it with their dikes and boat traffic.
Sorry if you took that the wrong way gordy, since you and I have quoted each other before with a little levity. It was intended as a light joke which we often do with each other. I was not aware you would take offense and thought you would enjoy it. I was wrong. I didn't call you stupid or even corrected you in a manner which would have been offensive. I do know what the word "usually" means which was in your quote. When you referred to me as "genius" I did take offense to that. And a very Merry Christmas to you as well. I hope you get some joy and Holiday Spirit.
Australian Government Bureau of Meteorology
Northern Territory
Darwin Regional Forecasting Centre
TOP PRIORITY FOR IMMEDIATE BROADCAST
Media: The Standard Emergency Warning Signal should NOT be used with this
warning.
TROPICAL CYCLONE WARNING
TROPICAL CYCLONE ADVICE NUMBER 31
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 11:00 am CST [9:30 am WST] Tuesday 15 December 2009
A Cyclone WARNING continues for coastal areas from Cockatoo Island to Wyndham.
A Cyclone WATCH continues for coastal areas from Beagle Bay to Cockatoo Island.
At 9:30 am CST [8:00 am WST] Severe Tropical Cyclone Laurence, Category 3 was
estimated to be 85 kilometres north northwest of Kalumburu and 140 kilometres
north northeast of Mitchell Plateau and moving southwest at 8 kilometres per
hour.
The VERY DESTRUCTIVE core of SEVERE TROPICAL CYCLONE Laurence is expected to
move southwest parallel to the Kimberley coast during today.
VERY DESTRUCTIVE WINDS with gusts to 185 kilometres per hour are currently being
experienced near the coast around Troughton Island and are expected to extend
southwest along the coast to Mitchell Plateau during today. DESTRUCTIVE WINDS
with gusts to 130 kilometres per hour may extend further southwest to Kuri Bay
overnight.
GALES with gusts to 110 kilometres per hour may extend further along the coast,
reaching as far as Cockatoo Island on Thursday morning and as far as Beagle Bay
later on Thursday or Friday, if the cyclone maintains its current track.
HEAVY RAIN is expected to continue over the north Kimberley region today,
extending into the western Kimberley during today and Wednesday.
FESA-State Emergency Service advises of the following community alerts:
YELLOW ALERT: People in or near the communities of Kalumburu, Mitchell Plateau
and Faraway Bay should be taking action in preparation for the cyclone's
arrival.
BLUE ALERT: People in or near the communities of Kuri Bay and Cockatoo Island
should start taking precautions.
Details of Severe Tropical Cyclone Laurence at 9:30 am CST [8:00 am WST]:
.Centre located near...... 13.6 degrees South 126.3 degrees East
.Location accuracy........ within 30 kilometres
.Recent movement.......... towards the southwest at 8 kilometres per hour
.Wind gusts near centre... 165 kilometres per hour, and slowly intensifying
.Severity category........ 3
.Central pressure......... 977 hectoPascals
The next advice will be issued by 2:00 pm CST Tuesday 15 December[12:30 pm WST
Tuesday 15 December].
This advice is available on telephone NT-1300 659 211 and WA-1300 659 210
DARWIN Tropical Cyclone Warning Centre
The only time Mississippi river water gets in the lake is when NOLA is threatened by high water levels in the river and Army corps floodgates are opened. That happens less than every 10 years, and then isn't usually for more than a week.
You should hear the ecologists scream...
Just as an observer and by no means an expert, my views on Climate Change:
1. Yes, CC has been around since the genesis of planet Earth and will continue.
2. Yes, humans have contributed negatively to the cycle. To what extent, I do not know.
3. Money wise…an ounce of prevention, cutting down on the crap that is spewed into our atmosphere, is cheaper than a pound of cure.
4. Some bloggers have the mindset that it will not affect me during my life, so who cares. To not include what may happen to future generations….and some unpleasant things may happen…does not make sense to me.
Grothar, mind coming to a much quieter chat now?
Not at all canes. At least you don't insult me when I am trying to be friendly. LOL
Confirmed: Yes Men Behind Prank Of Canada At COP15
Some of their earlier work.
Excellent post Geoff, but most of us are busy watching TV. You brought up some good points. Why worry about the next generation if we aren't going to be around anyway. Let them solve their own problems. I learned that in Sunday school. Ever check your mail???
Would have been a little uglier...
It's perfect as it stands, Geoff.
I think you're being very courteous, which is your way.
If I could write something as clear and concise, my last few words would be:
To not include what may happen to future generations...would be unethical and immoral.
But that's just from a raging menopausal grandmother...OH MY! :)
SPC Storm Reports
Uh, how's that workin' for ya'?
(Think maybe I missed something in the previous conversation?)
Just watching some chevy chase.
Local Text Forecast for
Miami, FL
Dec 14 Tonight
Mainly clear. Areas of fog. Low 73F. Winds ENE at 10 to 15 mph.
Dec 15 Tomorrow
Areas of morning fog. A few passing clouds, otherwise generally sunny. High 83F. Winds ESE at 5 to 10 mph.
Dec 15 Tomorrow night
Clear to partly cloudy. Humid. Low 71F. Winds light and variable.
Dec 16 Wednesday
Showers possible in the afternoon. Highs in the low 80s and lows in the low 70s.
Dec 17 Thursday
Chance of showers. Highs in the upper 70s and lows in the upper 60s.
Dec 18 Friday
Showers possible. Highs in the upper 70s and lows in the mid 60s.
Dec 19 Saturday
Showers possible. Highs in the upper 70s and lows in the low 60s.
Dec 20 Sunday
More clouds than sun. Highs in the low 70s and lows in the mid 50s.
Dec 21 Monday
Cloudy. Highs in the low 70s and lows in the upper 50s.
Dec 22 Tuesday
Clouds giving way to sun. Highs in the low 70s and lows in the upper 50s.
Dec 23 Wednesday
Sunny. Highs in the low 70s and lows in the mid 60s.
Christmas Vacation on AMC
Blow it out you tuberfluben Grothar!
Radar Loop 1 Loop 2
Australian Government Bureau of Meteorology
Northern Territory
Darwin Regional Forecasting Centre
TOP PRIORITY FOR IMMEDIATE BROADCAST
Media: The Standard Emergency Warning Signal should NOT be used with this
warning.
TROPICAL CYCLONE WARNING
CORRECTED TROPICAL CYCLONE ADVICE NUMBER 31
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 11:20 am CST [9:50 am WST] Tuesday 15 December 2009
A Cyclone WARNING continues for coastal areas from Cockatoo Island to Wyndham.
A Cyclone WATCH continues for coastal areas from Beagle Bay to Cockatoo Island.
At 9:30 am CST [8:00 am WST] Severe Tropical Cyclone Laurence, Category 3 was
estimated to be 85 kilometres north northwest of Kalumburu and 140 kilometres
north northeast of Mitchell Plateau and moving southwest at 8 kilometres per
hour.
The VERY DESTRUCTIVE core of SEVERE TROPICAL CYCLONE Laurence is expected to
move southwest parallel to the Kimberley coast during today.
VERY DESTRUCTIVE WINDS with gusts to 165 kilometres per hour are currently being
experienced near the coast around Troughton Island and are expected to extend
southwest along the coast to Mitchell Plateau during today. DESTRUCTIVE WINDS
with gusts to 130 kilometres per hour may extend further southwest to Kuri Bay
overnight.
GALES with gusts to 110 kilometres per hour may extend further along the coast,
reaching as far as Cockatoo Island on Thursday morning and as far as Beagle Bay
later on Thursday or Friday, if the cyclone maintains its current track.
HEAVY RAIN is expected to continue over the north Kimberley region today,
extending into the western Kimberley during today and Wednesday.
FESA-State Emergency Service advises of the following community alerts:
YELLOW ALERT: People in or near the communities of Kalumburu, Mitchell Plateau
and Faraway Bay should be taking action in preparation for the cyclone's
arrival.
BLUE ALERT: People in or near the communities of Kuri Bay and Cockatoo Island
should start taking precautions.
Details of Severe Tropical Cyclone Laurence at 9:30 am CST [8:00 am WST]:
.Centre located near...... 13.6 degrees South 126.3 degrees East
.Location accuracy........ within 30 kilometres
.Recent movement.......... towards the southwest at 8 kilometres per hour
.Wind gusts near centre... 165 kilometres per hour
.Severity category........ 3
.Central pressure......... 977 hectoPascals
The next advice will be issued by 2:00 pm CST Tuesday 15 December[12:30 pm WST
Tuesday 15 December].
RPBOLMAA (That is Norwegian for Roll on the floor and.................... LOL.
Next week Monday morning:
Viewing: 1551 - 1601
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 — Blog Index