(Daily News Scan - DNS English) Polar Vortex and Climate Change
Important Points:
A blast of Arctic air from the Polar Vortex brought dangerous, bone-chilling cold to a wide swath of the united states recently.
The brutal blast known as Polar Vortex is a stream of cold air that spins around the stratosphere over the North Pole. This counter-clockwise spinning rapid current of air prevents the rigid Arctic weather from escaping into other regions.
This swirling isn’t considered, a single storm or even a weather pattern as such. Occasionally, the vortex can become distorted and meander far further south than normal.
The mid-west was the hardest-hit region as the temperature there plunged below zero Fahrenheit (i.e. minus 18° Celsius).
It was also a factor in the “Bomb Cyclone” that battered the US east-coast last year.
There’s some evidence that the jet-stream, a meandering current that flows over North America and Europe, is slowing and becoming wavier as the planet warns. This jet stream interacts with the polar vortex, helping bring numbing temperatures further south.
Scientists also point to a complex sequence of events involving sea-ice, which is rapidly diminishing in the Arctic. As the ice retreats, summertime heat is absorbed by the dark ocean that lies underneath. This heat is then released into the atmosphere during winter, spurring winds that can disrupt the Polar Vortex.
The long and chilly winters in northern India this year could be linked to Polar Vortex breaking up. The cold from the Arctic has been spilling southwards into Europe and us due to the weakening of the westerly currents. This seems to be pashing western disturbances more southwards than normal, towards northern India. In effect, this is transmitting the cold from southern Europe into Northern India.
Western Disturbances are pulses of low pressure winds that travel westwards from in and around Mediterranean region, bringing cold moist winds that either hit the Himalayas- impacting Northern India- or blow over north.
Ironically the disruption in the polar vortex was caused by warm winds entering the upper atmosphere over the arctic causing “Sudden stratosphere warning” over the north pole that sent temperatures in the region rapidly up by tens of degrees. This sent the cold normally tapped in the arctic spilling out.
Now, the cold that has killed dozens is now all set to give way to spring- like weather according to the meteorologists.
