Diverse response of global climate and vegetation to astronomical forcing and CO2 during MIS-11 and MIS-13

Paleoclimate and paleovegetation reconstructions and simulations of the past interglacials has been paid significant attention, as it facilitates the prediction of future climate changes, especially in a warming world. However, understanding the mechanisms of how astronomical forcing and CO2 influence global climate and vegetation pattern remains challenging. Given the distinct differences in orbital configurations and climate/vegetation variations between MIS-11 and MIS-13, we performed two sets of transient simulations using LOVECLIM 1.3, one driven by insolation change only, and another one by changes in both insolation and CO2. These simulations offer us a good opportunity to investigate the relative effect of astronomical forcing and CO2 on global and regional vegetation changes. Our results show that the effects of precession and obliquity on vegetation depend strongly on regions, and the simulated results are in good agreement with vegetation reconstructions at key regions. The vegetation response differs widely between MIS-11and MIS-13, which is mainly caused by the difference in their astronomical configurations, and the difference in CO2 concentration between these two interglacials plays minor role. In addition to the effect of precession and obliquity, our simulations are also able to capture the half precession signal (~ 10 ka) in the climate and vegetation changes in the tropical regions in response to the tropical insolation