Something interesting is happening in the polar stratosphere. A 40-year cold spell is underway, and the temperature continues to drop. We know its cold because the stratosphere is starting to fill with colorful clouds. They look like this:
These are Type II polar stratospheric clouds (PSCs) photographed by Per Steinar Prøven of Brumunddal, Norway. "We have been seeing them day and night," he says.
Polar stratospheric clouds are rare. Normally, the stratosphere has no clouds at all. When the temperature drops to -85 C (188 K), however, water molecules can get together to form ice crystals even in the very dry stratosphere. High-altitude sunlight touching those crystals creates a blossom of pastel color.
According to NASA's MERRA2 climate model, temperatures in the polar stratosphere are about to drop to their lowest levels since before 1978. This could cause a major outbreak of polar stratospheric clouds, visible around the Arctic Circle and beyond.
https://spaceweather.com/
Polar stratospheric clouds are rare. Normally, the stratosphere has no clouds at all. When the temperature drops to -85 C (188 K), however, water molecules can get together to form ice crystals even in the very dry stratosphere. High-altitude sunlight touching those crystals creates a blossom of pastel color.
According to NASA's MERRA2 climate model, temperatures in the polar stratosphere are about to drop to their lowest levels since before 1978. This could cause a major outbreak of polar stratospheric clouds, visible around the Arctic Circle and beyond.
https://spaceweather.com/
RSS Feed
