Arguments
New Video: Climate, Jetstream, Polar Vortex
Posted on 5 February 2014 by greenman3610
This is a re-post from Climate Crocks
This is the first video to include interviews conducted at the American Geophysical Union Fall Meeting in San Francisco in December.
I started out with a focus on what we were hearing about extreme events, then took a little jog when the latest extreme even presented itself – our current polar vortex, which is a pretty good textbook example of the kind of weather that we may be seeing more of, paradoxically, in this case, cold snap made more likely by increasingly lazy jet stream flow.
This video contrasts arctic cold and snow in the east with mild temps and droughts in California.
Complete report on drought from California TV station KSBW below.
Additional report now up on dry lakes in the California area.
The jet stream doesn't actually direct these storm systems around the globe. It is a useful metaphor just as the solar model of the atom was a useful metaphor as far as it went. It was an improvement over the plum pudding model but not as good as the modern model. The jet stream marks the border between The Polar Hadley cell and the Ferrel cell and the rising air at this location both creates the jet stream and pushes weather systems around the globe. Here is another equally flawed but possibly useful metaphor. The jet stream is like a top that as it slows down begins to wobble until as it continues to slow down it falls over. In this case the slowing down is due to the Arctic heating up. Previously, the air over the Arctic radiated heat, became heavy and sunk giving great force to the Polar Hadley cell. As the Arctic gets warmer, this heavy air is less heavy and the polar Hadley cell slows. Without this force, the progress of the Rosby waves slows and the waves get deeper (wobble). Eventually, especially in the fall when the land cools off quickly while the ocean still is giving off its huge accumulation of heat from the summer open ocean, the Polar Hadley cell should reverse as air rises over the Arctic. At some point in this progression, the northern most jet stream should disappear and we will have a two cell system in the northern hemisphere. By by wheat crops plus corn soya and so forth if it occurs before these crops have ripened. On average, each year, with the usual ups and downs from year to year, this will become more extreme until we lock in to the new climate regime and trees are growing again right up to the shores of the Arctic ocean.
Here in the UK a super active jet stream has for the past 2 months been sending deep depressions, one after the other, across the Atlantic, with storm force winds and giving the south the wettest winter for over 200 years. Coastal defences have been battered away (including a coastal railway line), and large parts of Somerset have been under water for months - people have been evacuated from their homes and villages abandoned. More heavy rain and gales are forecast for the foreseeable future.
As far as metaphor goes, how about the difference between a rushing mountain creek heading directly down a valley vs. a slow meandering river on the plain? Slow the fluid down and a stuck high-amplitude pattern results.