One of the most confounding effects of climate change involves the increasing incidence of weather extremes that may include hot and cold. And snow and rain, and wet and dry, and drought and flooding.
Scientists have been examining this situation intensely over recent years, as America, Asia, and Europe have each experienced wave after wave of record-breaking weather events.
Now the picture is coming more clearly into view, and that’s the focus of a newly released two-part video feature (see below).
One of the leaders in this research, Jennifer Francis of Rutgers University, has now published a study that supports what a number of scientists have suspected for some time — that changes in the northern polar ice are having dramatic effects on the course of the jet stream.
The jet stream, a high-level flow of winds circling the northern latitudes, is the boundary between cold air to the north and warm air to the south. It is powered by the temperature differential between arctic and temperate latitudes.
As the arctic warms, and that temperature differential declines, the jet slows, becomes weaker, and begins to meander. Those meandering waves in the jet are more subject to “blocking patterns,” where weather in effect gets “stuck” over part of the northern hemisphere.
It all suggests a mechanism for the number of long-lasting heat, drought, rain, snow, and flood events that have been so prevalent over the past several years.
This Yale Forum “This Is Not Cool” video and a companion one look at the warm winter and weird spring of 2012. Experts interviewed for the videos include Francis of Rutgers; Kevin Trenberth of the National Center for Atmospheric Research; Jeff Masters of Weather Underground; and meteorologists Paul Douglas of Weathernation and Scott Mandia of Suffolk County Community College in New York.
The related video in the two-part series is available here.