Risk of simultaneous heat waves in Western Europe, North America and Asia due to atmospheric waves, ripples generated by the collision between two air masses of different temperatures. Still in the atmosphere, rivers of steam are at the origin of violent floods. This is shown by two studies published respectively in the journal Nature Climate Change and conducted by the British University of Oxford group coordinated by Kai Kornhuber, and in the journal Science Advances by the University of California at San Diego.
The first study indicates that the winds following specific patterns are at the origin of atmospheric waves capable of generating simultaneous heat waves in North America, Western Europe and Asia. "The heat waves that occur simultaneously - says Kornhuber - will become more serious in the coming decades if the greenhouse gases are not mitigated. In an interconnected world this can lead to peaks in the price of food and have repercussions on the availability of food even in regions remote, not directly affected by heat waves ".
Areas at risk of simultaneous heat waves correspond to highly productive areas from the agricultural point of view. "We have found - continues Kornhuber - a 20-fold increase in the risk of simultaneous heat waves in the main crop-producing regions when specific wind patterns are present on a global scale. So far this was an undervalued vulnerability in the food system".
In the second study, researchers found instead that atmospheric rivers, long corridors and narrow water vapor in the atmosphere capable of carrying more than twice the volume of the Amazon, are the engine that generates storms responsible for flooding. It is calculated, for example, that in some coastal areas of Oregon and northern California atmospheric rivers are responsible for over 99% of all flood damage.
