The spatial-temporal patterns of East Asian climate in response to insolation, CO2 and ice sheets during MIS-5
Anqi Lyu, Qiuzhen Yin
Abstract
Marine Isotope Stage (MIS) 5, between about 130 and 70 ka BP, is characterized by climate oscillations consisting of three interstadials and two stadials. Many climate simulations have been performed for the warmest MIS-5e period, but few has been made to cover the entire MIS-5 to investigate the climate variability during this long period. In this study, two sets of snapshot simulations by a step of 2 ka covering the whole MIS-5 period are performed with the model HadCM3 to investigate the relative impacts of insolation, CO2 and Northern Hemisphere ice sheets on the East Asian climate variability. Our results show that precipitation and temperature in different subregions in East Asia have different sensitivity to astronomical forcing, CO2 and ice sheets, in particular when seasonal and mean annual changes are concerned. The variability of temperature and precipitation within MIS-5 is mainly controlled by precession but their magnitudes are modulated by CO2 and ice sheets. The impact of ice sheets on summer precipitation vary between subregions and is sensitive to ice sheet configurations and background insolation. The summer precipitation in southern China is more sensitive to ice sheets than in northern China. Moisture budget analysis show that insolation and CO2 affect the summer precipitation by the dynamic and thermodynamic processes, respectively, and the impact of ice sheets is mainly through the vertical dynamic processes which is strongly associated with the ice sheet-induced wave train at the hemisphere scale.