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

依据最新的古气候耦合模式比较计划(PMIP4)协议, 利用完全耦合的气候模式CESM1.0, 研究中全新世与工业革命前气候的差异, 量化地球轨道参数(ORB)和温室气体(GHG)对中全新世气候变化的影响。3个模拟试验结果表明, 与工业革命前相比, 中全新世北半球高纬度地区气候偏温, 全球其他地区气候偏冷, 北半球大部分地区更湿润, 南半球则较为干燥; ORB导致全球中高纬度地区升温, GHG在降低全球气温和减少中高纬度地区降水方面发挥作用; 这种差异引起大气和海洋环流的变化, 导致地球经向热量输送的差异; 就总经向热量输送的变化范围而言, ORB对气候的影响大约是GHG的5倍。研究结果对深入了解中全新世气候及其对不同外部强迫的响应有积极意义。

中全新世, 全球气候, 地球轨道参数, 温室气体, 经向热量输送