Thursday, January 24th 2013, 6:43 AM EST
Only now, in the troposphere, you begin to feel the effects of the powerful "Stratwarming" earlier this month that it is on top of the Arctic Ocean. The sudden warming of the stratosphere in the coming weeks could cause a real disruption in the troposphere, favoring the occurrence of major cold spells in the area of Canada, the northern United States, along with European countries and those of central and northern Asia .
In general, the "Stratwarming" probably begins to occur when the hemispheric general circulation begins to present a trend rather wavy, for the development of "forcing" tropospheric more and more intense, especially between the North Pacific and North Atlantic, where go to build impressive "blocking" (cliffs anticyclonic blocking, lying along the meridians) that stop the raging current neighborhood. In this phase above the Arctic latitudes, because of the intense "forcing" the upper troposphere, may occur of the intense heating stratospheric that tend to propagate towards the upper troposphere, favoring an appreciable increase of geopotential values ranging to establish a powerful cell dynamics tropospheric anticyclone over the Arctic.
But most likely, these sudden and intense overheating of the stratosphere over the Arctic, can be induced also sensitive to variations in solar activity, given the particular interaction that exists between the solar radiation and the ozone layer in the stratosphere existing. We must consider that in an event of "Major Stratwarming" strong enough, temperatures in the Arctic lower stratosphere can increase dramatically, even +50 ° C +60 ° C than the standard values. A thermal anomaly positive truly impressive that produces a real upheaval baric on the troposphere below. The mechanism is always the same.
The intense overheating, which affects the lower part of the stratosphere, inevitably tends to extend downwards, affecting also the upper troposphere. Here, the significant increase in heat that flows from the stratosphere produces a sharp increase in geopotential values. It is thus to create maximum geopotential, between lower stratosphere and upper troposphere, which tend to test a massive cyclonic area, well structured in the upper troposphere, which extends further downwards, going so to destabilize the figure of the vortex polar, which, of all anticyclonic response to the attack and the sudden increase of geopotential altitude, it will break into two or more "lobes" ("Split") moving to middle latitudes, between the Northern Asia, North America and Europe.
Drifting, including North America, Europe and Asia, north-central, the various "lobes" of the polar vortex, now broken up into sections by the powerful anticyclonic circulation established over the North Pole, will tend to cause conditions intense storms, with widespread snowfall and a significant drop in temperatures in the areas most affected. The various "lobes" side of the polar vortex, slipping to middle latitudes, are fed by the constant flow of air masses very cold, arctic extraction, driven by the strong anticyclone Arctic is going to be placed, temporarily, above the Arctic Ocean, with maximum baric which can often exceed the 1040-1050 hpa. In the last ten years there has been a considerable increase in episodes of "Stratwarming", possibly related to the loss of Arctic sea ice. In fact, the summer of 2007 to that of 2012, the Arctic sea ice reached its lowest extent ever recorded since have entered the scene data from the polar satellite in 1979.
In general, each time you is to realize an intense "Stratwarming", the cyclonic area that typically runs over the North Pole, also known by the term polar vortex, is strongly weakened or replaced by the formation of a robust anticyclone arctic, ready to deliver intense cold spells ready to head for the temperate area, while the phases of the Arctic live much milder climate, with average temperatures above average for the period.
These cold spells can occur even after thirty days from the beginning of the "Stratwarming." With regard to the current event notice immediately as the heating layer is able to propagate up to the high troposphere, managing to increase the geopotential high above the Arctic, with the formation of a powerful anticyclone Arctic, with maximum baric ready to touch the 1060-1064 hpa in the northern part of the East Siberian Seas, just north-east of the islands of New Siberia.
The development of this powerful cyclone in the middle of the Arctic region has literally cut in half the figure of the tropospheric polar vortex, allowing air icy polar extraction to expand from the Arctic Ocean in the direction of the Canadian Northern and Central Europe and most of the Siberian sector, where for days but it remains intense waves of ice, accompanied by heavy snowfall and strong winds brought by the action of the disturbing "lobe" Siberian.
In the coming weeks the influence of this powerful cyclonic system, the result of the intense "Stratwarming", will have as its main effect a radical weakening of the main branch of the "polar jet", with the formation of large resonant planetary waves, capable of erect imposing "blocking" (cliffs anticyclonic blocking, lying along the meridians) ready to stop the flow of current neighborhood for the most profitable exchanges meridians (thermal exchange between pole and tropic) converging towards the Arctic Ocean.
In short, there is nothing better for the implementation of major waves of ice ready to slide up to the temperate zone, with possible grievances up to the sub-tropical latitudes. After the mid-western Siberia and north-central part of Europe the next to suffer the effects of this "Stratwarming" in early 2013 will be just as Canada and the northern United States, ready to be hit later this month by major eruptions of cold air, can bring snow and ice to the south of the U.S., after a start unusually mild winter weather and no snow.