Previous studies suggest a robust intensification of the zonally averaged hadley circulation(HC)during boreal winter in recent decades,but little is known regarding the regional HC.This study investigates long-term tr...Previous studies suggest a robust intensification of the zonally averaged hadley circulation(HC)during boreal winter in recent decades,but little is known regarding the regional HC.This study investigates long-term trends of the winter regional HC over the western pacific(WPHC)since 1979 using six reanalysis datasets.It is found that there are large discrepancies in the long-term trends of WPHC intensity among the six datasets.Specifically,three of the six reanalyses(erainterim,20CR and CFSR)show no discernible long-term trends,whereas NCEP-1,NCEP-2 and JRA-55 display pronounced intensification tendencies.Results in this study suggest that,although the warming trend of SST in the western tropical pacific identified in previous studies is robust,uncertainty remains regarding the long-term trends in the WPHC intensity.This raises a question about the factors involved in changes of the WPHC intensity.展开更多
基金supported jointly by the National Key Research and Development Program [grant number 2016YFA0600604]the National Natural Science Foundation of China [grant numbers 41605050,41230527,and 41661144016]+2 种基金the Jiangsu Collaborative Innovation Center for Climate Changethe Young Elite Scientists Sponsorship Program by CAST [grant number 2016QNRC001]the China Postdoctoral Science Foundation [grant number 2017T100102]
文摘Previous studies suggest a robust intensification of the zonally averaged hadley circulation(HC)during boreal winter in recent decades,but little is known regarding the regional HC.This study investigates long-term trends of the winter regional HC over the western pacific(WPHC)since 1979 using six reanalysis datasets.It is found that there are large discrepancies in the long-term trends of WPHC intensity among the six datasets.Specifically,three of the six reanalyses(erainterim,20CR and CFSR)show no discernible long-term trends,whereas NCEP-1,NCEP-2 and JRA-55 display pronounced intensification tendencies.Results in this study suggest that,although the warming trend of SST in the western tropical pacific identified in previous studies is robust,uncertainty remains regarding the long-term trends in the WPHC intensity.This raises a question about the factors involved in changes of the WPHC intensity.
