Wednesday, March 20, 2013

Extreme Weather Tied To Arctic Ice Loss

One expert's take on the extreme winter worldwide:

It's the first day of spring, but winter remains firmly entrenched over the eastern half of the U.S., where temperatures of 5 - 25°F below average have been the rule all week. The culprit is the jet stream, which has taken on an unusually contorted shape that is allowing cold air to spill down over the Eastern U.S. and Western Europe, but bringing near-record warmth to portions of Greenland...

Unusual winter jet stream patterns tied to Arctic sea ice loss
Unusual jet stream contortions in winter have become increasingly common in recent years, according to a March 2013 paper by Tang et al., "Cold winter extremes in northern continents linked to Arctic sea ice loss"... 
They theorized that sea ice loss in the Arctic promotes more evaporation, resulting in earlier snowfall in Siberia and other Arctic lands. The earlier snow insulates the soil, allowing the land to cool more rapidly. This results in a southwards shift of the jet stream and builds higher atmospheric pressures farther to the south, which increases the odds of cold spells and blocking high pressure systems that can cause extended periods of unusually cold and snowy weather in the mid-latitudes.

3 comments:

Anonymous said...

you truly are out of your fucking mind

zombie rotten mcdonald said...

yeah, because meteorology is CRAZY.

jimspice said...

There are certain "tipping point" events which have almost unimaginable consequences. There was once an immense fresh-water lake across much of Canada and the northern U.S., contained to the east by a massive ice dam. During one slightly warmer than usual thaw caused a breech in the dam, which turned into a torrent, emptying the entire contents of the lake in a matter of days. Not only did we get the cool standing rock formations of WI Dells, but the sudden influx of cold, fresh water into the ocean basically shut down ocean currents, resulting in much colder northern latitudes and much warmer tropics. Just like a pile of sand, grains can be dropped one by one with no effect, until one seemingly random grain will cause an unstoppable cascade, causing the pile to crumble. There was nothing special about that one grain; it's just the nature of randomness.