We use a single aerosol model to explore the effects of the differing meteorological fields from the NCAR CAM5 and GFDL AM3 models. We simulate the global distributions of sulfate, black carbon, organic matter, dust and sea salt using the University of Michigan IMPACT model and use these fields to calculate aerosol direct and indirect forcing, thereby isolating the impacts of the differing meteorological fields. Over all, the IMPACT-AM3 model predicts larger burdens and longer aerosol lifetimes than the IMPACT-CAM5 model. However, the IMPACT-CAM5 simulations transport more black carbon to the polar regions and more dust from Asia towards North America. These differences can mainly be attributed to differences in: (1) the vertical cloud mass flux and large-scale precipitation fields which determine the wet deposition of aerosols; (2) the in-cloud liquid water content and the cloud coverage which determine the wet aqueous phase production of sulfate. The burden, lifetime and global distribution, especially black carbon in polar regions, are strongly affected by choice of the parameters used for wet deposition. The total annual mean aerosol optical depth (AOD) at 550 nm ranges from 0.087 to 0.122 for the IMPACT-AM3 model and from 0.138 to 0.186 for the IMPACT-CAM5 model (range is due to different parameters used for wet deposition). Even though IMPACT-CAM5 has smaller aerosol burdens, its AOD is larger due to the much higher relative humidity in CAM5 which leads to more hygroscopic growth. The corresponding global annual average anthropogenic and all-sky aerosol direct forcing at the top of the atmosphere ranges from-0.25 W m ~(-2) to-0.30 W m ~(-2) for IMPACT-AM3 and from-0.48 W m ~(-2) to-0.64 W m ~(-2) for IMPACT-CAM5. The global annual average anthropogenic 1st aerosol indirect effect at the top of the atmosphere ranges from-1.26 W m ~(-2) to-1.44 W m ~(-2) for IMPACT-AM3 and from-1.74 W m ~(-2) to-1.77 W m ~(-2) for IMPACT-CAM5.
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机译：我们使用单个气溶胶模型来探究NCAR CAM5和GFDL AM3模型对不同气象领域的影响。我们使用密歇根大学IMPACT模型模拟了硫酸盐，黑碳，有机物，粉尘和海盐的全球分布，并使用这些字段来计算气溶胶的直接和间接强迫，从而隔离了不同气象领域的影响。总体而言，与IMPACT-CAM5模型相比，IMPACT-AM3模型可预测更大的负担和更长的气溶胶寿命。但是，IMPACT-CAM5模拟将更多的黑碳输送到极地，更多的粉尘从亚洲输送到北美。这些差异主要可归因于以下方面的差异：（1）垂直云团质量通量和决定气溶胶湿沉降的大规模降水场; （2）决定硫酸盐湿水相产生的云中液态水含量和云量。负担，寿命和整体分布，特别是极区的黑碳，受选择用于湿法沉积的参数的强烈影响。 IMPACT-AM3模型在550 nm处的年平均气溶胶光学深度（AOD）范围从0.087到0.122，IMPACT-CAM5模型的范围在0.138到0.186（范围是由于用于湿法沉积的参数不同）。尽管IMPACT-CAM5的气溶胶负荷较小，但由于CAM5中的相对湿度高得多，其AOD值也较大，这导致吸湿性增加。大气层顶部相应的全球年平均人为和全天候气溶胶直接强迫范围从IMPACT-AM3的-0.25 W m〜（-2）到-0.30 W m〜（-2）和-0.48 W m IMPACT-CAM5的〜（-2）至-0.64 W m〜（-2）。全球最高年平均人为第一气溶胶间接效应在IMPACT-AM3的范围从1.26 W m〜（-2）到1.44 W m〜（-2），从1.74 W m〜（-2 ）至IMPACT-CAM5的1.77 W m〜（-2）。
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