Huge atmospheric rivers are linked to the ten largest winter floods in the UK, since 1970.
Such events may become more frequent and severe if greenhouse gas emissions accelerate.
Atmospheric rivers are huge flows of moist air of at least two thousand and a width of several hundred kilometers. They run into the mid-latitudes of the lower troposphere, where winds of more than 12.5 m / s are able to carry as much water as the Amazon. At any time, for four or five atmospheric rivers is about 90% water, moving toward the poles.
David Levers University of Reading (UK) and his colleagues combined the historical data on river flows and weather information with the results of computer modeling of atmospheric rivers. There was a strong correlation between the latter and the floods.
In November 2009, for example, in the county of Cumbria dropped record rainfall that caused flooding. This event coincided with ekstratropicheskim cyclone, which sent the atmospheric river to the UK. Cyclone and the Cumbrian mountains contributed to the growth of the river, cool it, and eventually she lost all the cargo in a few days.
Will climate change on atmospheric river? Michael Dettinger of the Institute of Oceanography. Scripps (USA) studied the "Pineapple Express" — an atmospheric river, which brings water from the tropics near Hawaii to California. He took advantage of seven global circulation models and found that the increase in evaporation due to higher temperatures will lead to more frequent in California storms induced by this river. According to him, there is no reason to expect that the UK will be different.
The results of research published in the journal Geophysical Research Letters and Journal of the American Water Resources Association.
Prepared according to NewScientist.