Monday, January 19, 2009

Classic Gauze: East to West Winds

My mother loves this post so I republish it for her. The ancient climate for America was much different than it is today.
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Originally published February 1, 2007


Today the prevailing winds blow west to east in the continental United States. This has not always been the case however. During the last ice age (36,000 to 14,000 years ago) winds blew from east to west.

Today's Pacific Northwest known for raining every three days was once much drier due to the previous wind direction for example. The glaciers would have created a wind and moisture barrier which would cause the boundary of the glaciers to have weather like Mount Washington.

Scientists speculate that the winds change course with significant climate change. Just goes to show how the idea of a "natural equilibrium" is flawed and how volatile our world is. (Hat tip: Very Spatial)

2 comments:

karnala said...

At first I thought the wind changes could just be the normal pattern of ENSO until I read this article "The Great Climate Flip-flop" by WILLIAM H. CALVIN, which also bring into question the "natural equilibrium".

ONE of the most shocking scientific realizations of all time has slowly been dawning on us: the earth's climate does great flip-flops every few thousand years, and with breathtaking speed. We could go back to ice-age temperatures within a decade ˜ and judging from recent discoveries, an abrupt cooling could be triggered by our current global-warming trend....

What paleoclimate and oceanography researchers know of the mechanisms underlying such a climate "flip" suggests that global warming could start one in several different ways.

For a quarter century global-warming theorists have predicted that climate creep was going to occur and that we needed to prevent greenhouse gases from warming things up, thereby raising the sea level, destroying habitats, intensifying storms, and forcing agricultural rearrangements. Now we know ˜ and from an entirely different group of scientists exploring separate lines of reasoning and data ˜ that the most catastrophic result of global warming could be an abrupt cooling.

We are in a warm period now. Scientists have known for some time that the previous warm period started 130,000 years ago and ended, 117,000 years ago, with the return of cold temperatures that led to an ice age. But the ice ages aren't what they used to be. They were formerly thought to be very gradual, with both air temperature and ice sheets changing in a slow, 100,000-year cycle tied to changes in the earth's orbit around the sun. But our current warm-up, which started about 15,000 years ago, began abruptly, with the temperature rising sharply while most of the ice was still present. We now know that there's nothing 'glacially slow' about temperature change: superimposed on the gradual, long-term cycle have been dozens of abrupt warmings and coolings that lasted only centuries.

Anonymous said...

Yes, I do love this post. But a question, when do scientists think the winds switched west to east (like now) and how did the east to west winds affects climate in the middle of America. "The Mom"