||The robustness of future changes in Northern Hemisphere blocking: A large ensemble projection with multiple sea surface temperature patterns
Matsueda, MioEndo, Hirokazu
Geophysical research letters
5166 , 2017-05 , American Geophysical Union
Future changes in the frequency of Northern Hemisphere blocking are investigated via large ensemble simulations using a 60 km mesh atmospheric general circulation model prescribed with six future sea surface temperature patterns derived from state-of-the-art climate models under a 4 K warmer climate. Our simulations depict the frequency of wintertime blocking decreasing from 16.6% ± 0.7% to 13.1% ± 2.1% in the Euro-Atlantic sector and from 17.4% ± 0.7% to 14.8% ± 2.4% in the Pacific sector. This decline in frequency is seen to affect Euro-Atlantic blocking of all durations and Pacific blocking of more than 15 days' duration. During summer, our simulations not only exhibit a robust decrease (from 10.7% ± 0.4% to 7.6% ± 0.7%) in the Euro-Atlantic blocking frequency but also show that the magnitude of this decrease is smaller for longer-lived blocking. In contrast, the Pacific blocking frequency either does not change or increases slightly, particularly for events of 15–29 days' duration.