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Observed and projected decrease in Northern Hemisphere extratropical cyclone activity in summer and its impacts on maximum temperature
Author(s) -
Chang Edmund K. M.,
Ma ChenGeng,
Zheng Cheng,
Yau Albert M. W.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl068172
Subject(s) - extratropical cyclone , cyclone (programming language) , environmental science , middle latitudes , northern hemisphere , climatology , cloud cover , atmospheric sciences , climate change , geology , cloud computing , oceanography , field programmable gate array , computer science , computer hardware , operating system
Extratropical cyclones cause much of the high‐impact weather over the midlatitudes. With increasing greenhouse gases, enhanced high‐latitude warming will lead to weaker cyclone activity. Here we show that between 1979 and 2014, the number of strong cyclones in Northern Hemisphere in summer has decreased at a rate of 4% per decade, with even larger decrease found near northeastern North America. Climate models project a decrease in summer cyclone activity, but the observed decreasing rate is near the fastest projected. Decrease in summer cyclone activity will lead to decrease in cloud cover, giving rise to higher maximum temperature, potentially enhancing the increase in maximum temperature by 0.5 K or more over some regions. We also show that climate models may have biases in simulating the positive relationship between cyclone activity and cloud cover, potentially underestimating the impacts of cyclone decrease on accentuating the future increase in maximum temperature.