WASHINGTON — If it seems as though this winter has been endless, you’d better get used to it.
Mark Fischetti, senior editor at Scientific American, says that the jet stream – the river of air in the northern hemisphere that blows west to east and drives most of the region’s weather – has been changing, and it means that extreme- weather periods will last longer.
The jet stream takes some north-south dips as it works its way across the country, but the Arctic is warming at a faster rate than the rest of the planet, Fischetti says.
“When the temperature difference is less, it tends to make the jet stream wavy,” he says.
Big dips in the waves have resulted in the cold and snow that have plagued the D.C. area and much of the South this winter, and when the jet stream is weaker, those dips “stay locked in place longer.”
Those changes aren’t limited to winter weather either.
“Weather’s going to be different year to year to year,” Fischetti says, but hot weather, as well as cold weather and rainy periods, all last longer with a weaker jet stream that “gets stuck.”
The effects are being felt worldwide, Fischetti says. The jet stream continues across Europe and Russia, and the same effect means that “England is getting drowned this year” by long-lasting rainstorms.
Fischetti says it’s not just a normal fluctuation. The overall temperature of the earth is rising, but the fact that the gap between Arctic temperatures and the middle latitudes is narrowing points to the effects of global climate change.
So when the weather turns very cold, or for that matter very hot, scientists say a weaker, wavier jet stream could keep it that way longer.