The Motley Fool Discussion Boards
Miscellaneous / Climate Change
|Subject: Why sea ice records are poles apart||Date: 10/8/2012 1:26 PM|
|Author: PeterRabit||Number: 38271 of 64498|
Why are we seeing record highs and lows for sea ice at the same time?
When the Arctic experiences summer, it is winter in Antarctica. So when sea ice reaches its annual low in the north, every September, it is at its maximum extent in the south. Different processes determine the extent of the ice in different seasons. In summer, melting is the driving factor. But the extent of winter ice is determined mainly by winds, which can either push ice out over a larger area or compress it into a smaller one.
Long-term trends, extrapolated from satellite observations that began in the late 1970s, show that the September ice extent has grown around Antarctica and shrunk in the Arctic.
So why are these trends going in opposite directions?
What's happening in the Arctic?
What about the Antarctic?
Is anything happening with the jet stream in the northern hemisphere?
Given that winter sea ice in Antarctica is growing, is the alarm about the Arctic overblown?
Can we at least be fairly relaxed about the changes in the southern hemis