An oppressive heat wave baked Western Europe this week, setting record high temperatures in France, Germany, Poland and the Czech Republic. In India, a severe drought has choked water supplies in the city of Chennai, exposing its 9 million residents to a major shortage. And after the United States’ wettest 12-month stretch on record, towns across the Midwest and the Great Plains are reeling from devastating floods.
 |
| People bathe in the Trocadero Fountain in Paris during a severe heat wave on June 28, 2019. |
The reasons behind these extreme weather events are complex, but scientists believe they have a common trigger: profound recent changes to the jet stream, a ribbon of fast-moving air that flows from west to east over the Northern Hemisphere and controls weather systems.
The jet stream is powered by temperature differences between the cooler polar region to the north and warmer air masses to the south. As it circles the planet, this river of air can become rippled in places. The resulting troughs and ridges can create unusual weather patterns, amplifying cold snaps in one region and intensifying blasts of heat in another, said Jeff Masters, co-founder and director of meteorology for Weather Underground, a commercial weather service headquartered in San Francisco.
Read the NBC News story by Denise Chow - “A strange, wavy jet stream is blasting Europe with heat. Scientists say this could be the 'new normal.’"
No comments:
Post a Comment