中全新世, 全球气候, 地球轨道参数, 温室气体, 经向热量输送

According to the latest Paleoclimate Model Intercomparison Project (PMIP4) protocol, differences between the mid-Holocene and pre-industrial climates were investigated using the fully coupled climate model CESM1.0. The impact of the earth’s orbital parameters (ORB) and greenhouse gases (GHG) on mid-Holocene climate change were quantified. Three simulation experiments showed that compared with the pre-industrial simulation, the simulated mid-Holocene was warmer in the high-latitude of the northern Hemisphere, colder in the rest of the world, wetter in most of the northern hemisphere, and drier in the southern hemisphere. The ORB led to warming in the mid-to-high latitudes globally, while GHG played a role in lowering global temperatures and reducing precipitation in the mid-to-high latitudes. These differences in turn induced changes in atmospheric and oceanic circulation, ultimately resulting in differences in the Earth’s meridional heat transport. In terms of the variation in total meridional heat transport, ORB exerted approximately five times the climate impact compared with GHG. This study carried positive implications for deepening the understanding of the mid-Holocene climate and its response to various external forcings.

mid-Holocene, global climate, earth’s orbital parameter, greenhouse gases, meridional heat transport