中文摘要：

目前气候模式对沙尘气溶胶直接辐射强迫模拟仍有很大不确定性,多模式对比有助于定量评估不确定范围。国际大气化学—气候模式比较计划（Atmospheric Chemistry and Climate Model Intercomparison Project,ACCMIP）旨在评估当前模式对短寿命大气成分辐射强迫和气候效应的模拟能力。基于7个ACCMIP模式模拟的中国地区沙尘气溶胶浓度,我们评估了中国区域沙尘气溶胶直接辐射强迫和不确定性范围。结果显示,中国区域沙尘气溶胶年排放总量为215±163 Tg a-1,区域年均地表浓度为41±27μg m-3,柱浓度为9±4 kg m-2,光学厚度为0.09±0.05。中国区域年均沙尘气溶胶产生的大气顶短波、长波和总辐射强迫分别为-1.3±0.8 W m-2、0.7±0.4W m-2和-0.5±0.7 W m-2;地表短波、长波和总的辐射强迫值为-1.5±1.0 W m-2、1.8±0.9 W m-2和0.2±0.2 W m-2。沙尘气溶胶长波辐射强迫对沙尘浓度的垂直分布敏感。高层沙尘气溶胶浓度越大,其在大气顶产生更强的正值长波辐射强迫。然而,沙尘气溶胶短波辐射强迫主要受整层沙尘柱浓度控制,对沙尘浓度的垂直分布较不敏感。本文结果可为中国沙尘气溶胶的气候模拟提供参考。

英文摘要：

Large uncertainties exist in simulated direct radiative forcing by dust in climate models. Multi-model comparisons quantify the range of uncertainties in current climate models. The Atmospheric Chemistry and Climate Model Intercomparison Project（ACCMIP） is set up to evaluate the radiative forcing and climate effect of short-lived chemical species in the atmosphere. Based on simulated dust concentrations from 7 ACCMIP models, we quantify in this work the direct radiative forcing by dust in China and the range of uncertainties. Our results show that annual total emission, annual mean surface-layer concentration, burden, and AOD（Aerosol Optical Depth） of dust averaged over China are 215±163 Tg a-1, 41±27 μg m-3, 9±4 kg m-2, and 0.09±0.05, respectively. Simulated annual mean short-wave, long-wave, and net（short-wave plus long-wave） direct radiative forcings by dust averaged over China are, respectively,-1.3±0.8 W m-2, 0.7±0.4 W m-2, and-0.5±0.7 W m-2 at the top of the atmosphere and-1.5±1.0 W m-2, 1.8±0.9 W m-2, 0.2±0.2 W m-2 at the surface. Long-wave radiative forcing by dust is found sensitive to vertical distribution of dust concentrations. Dust aerosol in high altitudes contributes largely to long-wave radiative forcing at the top of the atmosphere. However, short-wave radiative forcing by dust is dependent on dust burden but not sensitive to its vertical distribution.