Flowers are blooming in England in January more than a month early. The Vail, Colorado ski resort has no natural snow for the first time in 30 years of operation while Homer Alaska had over 15 feet of snow by the tenth of January smashing all time records. Temperatures were strangely warm in the Dakotas with highs reaching the low seventies on Jan 5 & 6 in several towns in South Dakota, smashing records by as much as 15°F. Crocuses in England credit:Ben Birchall
Record Start to 2012
The first 10 days of 2012 have been warmer than anytime in recorded history across portions of the Northern Plains. This was mainly due to the lack of snow cover leading to unseasonably warm high temperatures. The average high temperature for the first 10 days in January (January 1-January 10) was warmer than previously recorded, in some instances by 6 degrees!
Record Warmth: January 5, 2012
A warm front pushed northeastward across Minnesota and brought with it very warm temperatures, making it feel more like late March or early April than the first week of January.
Temperatures soared across Minnesota where there was abundant sunshine and no snow on the ground. The highest temperature found so far from a National Weather Service Cooperative Station is 62 degrees at Marshall. Both Milan and Madison in southwestern Minnesota both saw 61 degrees. An automated station near Canby in Yellow Medicine County reached 63 degrees. Looking back to 1891 this is the first time a maximum temperature reached 60 degrees in the state for the first week of January. St. Cloud saw a record high of 53 degrees, breaking the old record of 43 degrees set in 1984. Clouds held the temperature down in the Twin Cities and "only" had a high of 45 degrees.
There has never been a 60 degree temperature recorded during the first week of January in Minnesota's modern climate record. The warmest temperature ever recorded in Minnesota during the first week of January is 59 degrees, occurring on January 7, 2003 in Amboy, MN. The warmest temperature ever recorded in Minnesota on January 5 is 57 degrees, recorded at Crookston in 1902.
The Pacific Storm Track Buried Alaska in Snow, While Drought Began in California.
The storm track across the Pacific, which is normally in the Pacific northwest or California in the first week of January, was far north dumping Homer Alaska with a record 15 feet of snow, and counting. The jet stream was far north of normal from Alaska to Europe. The cold air was locked up in Siberia, Alaska and the Arctic while drought rapidly developed in California.
The Sierra Nevada went a record two months in the rainy season without precipitation. Winter snows are beginning this week, 2 months late. Historic droughts in California have started with La Nina years like this one. Time will tell.
Atmospheric circulation patterns were the most extreme on record for December measured by an index called the North Atlantic Oscillation (NAO) according to Dr. Jeff Masters. A strong positive NAO has cold air in Canada moving offshore into the Labrador Sea while the U.S and Europe are warm. A Strongly positive NAO produces a tight pressure gradient and intense storms in the north Atlantic.
Hurricane hammered the holidays
December 26, 2011
One of the strongest hurricanes to ever hit Norway hammered coastal areas during the Christmas weekend and left a wide path of destruction throughout the south, west and northwest. Winds were clocked at more than 200 kilometers an hour, terrifying residents in many areas and leaving more than 100,000 homes without power.
EUMETSAT imagery shows Dagamr developing offshore of Iceland then striking Norway.
December 2011 jet stream pattern the most extreme on record.
The cause of this warm first half of winter is the most extreme configuration of the jet stream ever recorded, as measured by the North Atlantic Oscillation (NAO). The Arctic Oscillation (AO), and its close cousin, the North Atlantic Oscillation (which can be thought of as the North Atlantic's portion of the larger-scale AO), are climate patterns in the Northern Hemisphere defined by fluctuations in the difference of sea-level pressure in the North Atlantic between the Icelandic Low and the Azores High. The AO and NAO have significant impacts on winter weather in North America and Europe--the AO and NAO affect the path, intensity, and shape of the jet stream, influencing where storms track and how strong these storms become. During December 2011, the NAO index was +2.52, which was the most extreme difference in pressure between Iceland and the Azores ever observed in December (records of the NAO go back to 1865.) The AO during December 2011 had its second most extreme December value on record, behind the equally unusual December of 2006. These positive AO/NAO conditions caused the Icelandic Low to draw a strong south-westerly flow of air over eastern North America, preventing Arctic air from plunging southward over the U.S. and Europe.
Wild swings in the December Arctic Oscillation
This winter's remarkable AO/NAO pattern stands in stark contrast to what occurred the previous two winters, when we had the most extreme December jet stream patterns on record in the opposite direction (a strongly negative AO/NAO). The negative AO conditions suppressed westerly winds over the North Atlantic, allowing Arctic air to spill southwards into eastern North America and Western Europe, bringing unusually cold and snowy conditions. The December Arctic Oscillation index has fluctuated wildly over the past six years, with the two most extreme positive and two most extreme negative values on record. Unfortunately, we don't understand why the AO varies so much from winter to winter, nor why the AO has taken on such extreme configurations during four of the past six winters. Climate models are generally too crude to make skillful predictions on how human-caused climate change may be affecting the AO, or what might happen to the AO in the future. There is research linking an increase in solar activity and sunspots with the positive phase of the AO. Solar activity has increased sharply this winter compared to the past two winters, so perhaps we have seen a strong solar influence on the winter AO the past three winters. Arctic sea ice loss has been linked to the negative (cold) phase of the AO, like we observed the previous two winters. Those winters both had near-record low amounts of sunspot activity, so sea ice loss and low sunspot activity may have combined to bring a negative AO.
However, this winter with the AO reversed, Arctic sea ice extent is near the record minimum for the date and calculations of sea ice volume are at record lows. Last winter and the winter before that, very warm water around Greenland helped trigger deep lows in the Labrador sea while warm air blew over Greenland from its east coast.Gulf stream water pushed up towards Greenland, maintaining the pattern. This year, with a stronger, tighter Arctic atmospheric circulation and stronger westerly winds across the north Atlantic the warm water that originates in the Gulf Stream is being driven up the coast of Norway into the Arctic ocean.
The most extreme high temperature anomalies on earth this December and early January were not where the records were set in the United States. They are in the Arctic ocean where the sea ice is missing, over the Barents sea.
These storms released huge amounts of heat into the atmosphere above the Barents sea. The cold air that blew off of Greenland triggered convective overturning of the waters between Greenland and Iceland. The storms generated strong southerly winds from the north Atlantic into the Arctic.
The strong southerly winds along the coast of Norway strengthened the Norway current, driving warm Atlantic water into the Arctic, maintaining the ice free area. This is a pattern that has continued from the fall into the middle of January.
The warm salty Atlantic water, much of which originated in the Gulf Stream, is being driven by currents from the Barents sea deep into the Arctic ocean along the Siberian shelf. Numerical modeling of combined sea height data combined with gravity data measured from satellites interpolates the results of a small set of measured profiles of the Arctic ocean, tracking the warm Atlantic water as it flows off the Siberian shelf at 100 meters depth.
Air temperatures in December were lower than average over much of the Arctic Ocean, but higher than average over the Kara and Barents seas. Higher-than-average temperatures in these regions stemmed from two major factors. First, where sea ice extent is low, heat can escape from areas of open water, warming the atmosphere. Second, surface winds in the Kara and Barents Sea ice blew persistently from the south, bringing in heat from lower latitudes. This imported heat also helped to keep sea ice extent low in this area. Conditions over Canada were also unusually warm during December, but conditions over southeast Greenland have been 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) colder than average, partly because of northerly winds in the area.
Temperatures averaged up to 30°F where the sea ice was missing for the first week of January. This figure needs confirmation, but clearly the open ocean is releasing exceptional amounts of heat to the atmosphere where the ice is absent.
Positive phase of the Arctic Oscillation
The past two Arctic winters were dominated by a negative phase of the Arctic Oscillation, a large-scale weather pattern that brings generally warm conditions to the Arctic and colder conditions to Europe and North America. In contrast, the winter of 2011 has so far seen a mostly positive phase of the Arctic Oscillation. While temperatures were above normal in the Kara and Barents seas, the positive phase of the Arctic Oscillation tends to keep the coldest winter air locked up in the Arctic, which keeps the middle latitudes free of frigid Arctic temperatures and strong snowstorms. This weather pattern helps to explain the low snow cover and warm conditions over much of the United States and Eastern Europe so far this winter.
Several studies have shown that during the positive phase of the Arctic Oscillation, thick ice tends to move out of the Arctic through Fram Strait, leaving the Arctic with thinner ice that melts out more easily in summer. Scientists will be watching closely for this connection if the positive phase of the Arctic Oscillation continues through the winter.
Some scientists have speculated that the negative Arctic Oscillation pattern of the last two winters was in part driven by low sea ice extent. The recurrence of the positive phase of the Arctic Oscillation so far this winter, following a near-record low summer sea ice extent, suggests that other factors play an important role.
The continuing loss of sea ice appears to have become self-sustaining. Global warming has expanded the pool of warm water in the north Atlantic and more of that water is getting into the Arctic. It's a death spiral for Arctic sea ice.
A strong control of sea ice area (SIA) in the Nordic Seas in the period 1982–2006 by oceanic heat variability is reported. In particular, variability of summer Atlantic water temperature in the Barents Sea Opening explains about 75% of the variance of the following winter SIA anomalies which opens prospects for seasonal predictability of regional sea ice cover. A strong link of winter SIA anomalies to variability in the previous spring sea surface temperature on the western (Greenland Sea) and eastern (Barents Sea) sides of the Nordic Seas indicates that the oceanic control of sea ice cover in these areas mainly results from postsummer surface reemergence of oceanic heat anomalies generated by earlier atmospheric forcing. In particular, late winter North Atlantic Oscillation and anomalous winds across the Barents Sea ice edge significantly influence next winter sea ice cover on the western and eastern sides of the Nordic Seas, respectively.
After it loses heat in the Barents sea the warm salty Atlantic water becomes denser than the cold Arctic surface water which is freshened by the huge volume of river water that flows into the Arctic ocean. The Atlantic water forms a warm layer typically found beginning at about 200 meters deep in the Arctic ocean. The increased storminess in the Barents sea is apparently increasing the rate of flow of Atlantic water into the Siberian Basins of the Arctic, changing the Arctic currents and the distribution of salty and fresh water in the Arctic ocean.
Taken as a whole, the salinity of the Arctic Ocean is similar to the past, but the change in the freshwater pathway means the Eurasian Basin has gotten more saline while the Canada Basin has gotten fresher.
“The freshening on the Canadian side of the Arctic over the last few years represents a redistribution of freshwater, there does not seem to be a net freshening of the ocean,” Kwok said.
In the Eurasian Basin, the change means less freshwater enters the layer known as the cold halocline and could be contributing to declines in ice in that part of the Arctic, Morison said. The cold halocline normally sits like a barrier between ice and warm water that comes into the Arctic from the Atlantic Ocean. Without salt the icy cold freshwater is lighter, which is why it is able to float over the warm water.
The increasing salinity of the surface water along the Siberian shelf is increasing its density. When ice forms in the winter the exclusion of salt from the ice is making water that is cold and dense enough to sink into the warm salty Atlantic water below. This increased mixing of warm water is heating the Siberian side of the Arctic ocean and the air above it. The following summer, it is leading to faster ice melt, furthering the death spiral of summer Arctic sea ice.