razz
7-13-21, 1:59pm
It is all about understanding the jet stream and the influences impacting its flow.
I like Gywnne Dyer, a British journalist, writing article in terms that are easier for me to understand. During the severe cold snap in Texas in February and today's hot weather in the West US and CAN and Brazil, it starts with understanding the jet stream https://gwynnedyer.com/2021/texas-rossby-waves-and-wave-7/ and the Rossby waves.
The energy that drives the jet stream comes from the temperature difference between the two air masses it divides. However, the Arctic is warming much faster than the rest of the world, so that difference is shrinking – and with less energy, the jet stream is slowing down.
It used to blast straight east all the way around the planet, but even then it occasionally developed long S-shaped kinks called Rossby waves: big loops extending far north and south of its usual track. As it has slowed down (the average speed is now 150-225 kph), the Rossby waves have grown both more frequent and bigger.
They are often now great loops deviating far north and south from the straight track, and those loops bring with them cold polar air rarely seen so far south, or warm air not seen previously so far north. That’s what happened to Texas last week: one of those Rossby waves brought cold Arctic air all the way south – and then stuck for a while.
The jet stream itself didn’t stop. It just flowed all the way around that loop and kept going east, but the kink stayed put and the cold air in it froze Texas. This pattern will recur lots of times, and Texans will have to learn to live with it. Climate change doesn’t care whether you believe in it or not – and it may get worse...
I like Gywnne Dyer, a British journalist, writing article in terms that are easier for me to understand. During the severe cold snap in Texas in February and today's hot weather in the West US and CAN and Brazil, it starts with understanding the jet stream https://gwynnedyer.com/2021/texas-rossby-waves-and-wave-7/ and the Rossby waves.
The energy that drives the jet stream comes from the temperature difference between the two air masses it divides. However, the Arctic is warming much faster than the rest of the world, so that difference is shrinking – and with less energy, the jet stream is slowing down.
It used to blast straight east all the way around the planet, but even then it occasionally developed long S-shaped kinks called Rossby waves: big loops extending far north and south of its usual track. As it has slowed down (the average speed is now 150-225 kph), the Rossby waves have grown both more frequent and bigger.
They are often now great loops deviating far north and south from the straight track, and those loops bring with them cold polar air rarely seen so far south, or warm air not seen previously so far north. That’s what happened to Texas last week: one of those Rossby waves brought cold Arctic air all the way south – and then stuck for a while.
The jet stream itself didn’t stop. It just flowed all the way around that loop and kept going east, but the kink stayed put and the cold air in it froze Texas. This pattern will recur lots of times, and Texans will have to learn to live with it. Climate change doesn’t care whether you believe in it or not – and it may get worse...