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A Transient Modeling Study of the Latitude Dependence of East Asian Winter Monsoon Variations on Orbital Timescales
Author(s) -
Xie Xiaoxun,
Liu Xiaodong,
Chen Guangshan,
Korty Robert L.
Publication year - 2019
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 - 10.1029/2019gl083060
Subject(s) - northern hemisphere , climatology , geology , orbital forcing , insolation , latitude , boreal , forcing (mathematics) , southern hemisphere , glacial period , ice sheet , atmospheric sciences , oceanography , geomorphology , paleontology , geodesy
Transient simulations for the last 300,000 years are conducted to identify how orbital insolation, greenhouse gases, and ice sheets affect variations of the East Asia winter monsoon (EAWM). Results show that the southern EAWM's dominant period is 23 kyr in response to variations in boreal winter insolation (primarily from precession), while the northern EAWM's dominant period is 100 kyr and is most strongly modulated by Northern Hemisphere ice sheets, displaying a significant latitude dependence in orbital‐scale EAWM variations. The precession‐modulated boreal winter insolation can control the southern EAWM by influencing zonal land‐sea thermal contrast at low latitudes, while Northern Hemisphere ice sheets during glacial periods can strengthen the northern EAWM by forcing a powerful cyclonic circulation anomaly over northern Pacific. The different responses of southern and northern EAWM to orbital insolation and ice‐sheet forcings can further lead to in phase or out phase variations between the southern and northern EAWM.