黄土高原南部末次冰期以来沙尘气溶胶的气候效应

Climate Effect of Dust Aerosol in Southern Chinese Loess Plateau Since the Last Glacial Period

沙尘气溶胶是地球上分布最广的自然气溶胶类型之一,也是气候系统中的重要成分。沙尘天气严重影响人类生产、生活和居住环境,对气候变化也存在显著作用。近年来,沙尘气溶胶的气候效应得到越来越多的关注和研究,但人们的工作主要集中在对现代沙尘气溶胶的研究,而对过去沙尘气溶胶气候效应的研究不多。本研究利用黄土粒度及沉积特征,根据现代沙尘暴的沉降特点,研究了60kaB.P以来中国黄土高原南部地区沙尘气溶胶的辐射效应,结果表明:1)沙尘气溶胶产生的辐射效应主要表现在造成行星系统太阳辐射反射量的普遍增加,即沙尘过程具有明显的降温效应。2)气候效应上主要表现为对气候的负反馈。由沙尘粒度引起的行星反照率在全新世适宜期达最大值,而在冰期有最小值出现;在气候降温事件中,沙尘气溶胶造成行星反照率降低;每一次降温事件发生时气溶胶的降温效应会相应减弱。约60kaB.P以来沙尘气溶胶给年均温度带来的影响是使其平均降幅在-0.8K左右。3)利用黄土的粒度分布,结合现代气溶胶的观测可以估算地质时期沙尘气溶胶的气候效应。

Dust aerosol is one of natural aerosols and plays an important role in the climate system.In recent years,more and more investigators began to pay attention to the climate impact of dust aerosol.However,most studies were mainly focused on modern dust aerosol.Researches on the climate effect of dust aerosols in Quaternary was few.In the study,the climate effect of dust aerosol in the south of Chinese Loess Plateau over the past 60 kaB.P was studied by using the grain size distribution and the settlement velo...