Evaluation of the Direct Effects of Anthropogenic Aerosols on the Radiation Balance of the Atmosphere

霍布斯/抽象气溶胶可计划在地方、区域和全球范围内的大气辐射平衡中发挥重要作用。最近的估计表明，由于人为硫酸盐的直接影响而造成的全球平均气候强迫可能在规模上类似于(但在符号上相反)由人为“温室”气体产生的气候强迫。然而，估计气溶胶效应有很大的不确定性。这项研究的目的是获得将减少这些不确定性的大气气溶胶的测量结果(重点是来自人为来源的大气气溶胶)。拟议的研究包括两项主要活动。(A)测量太平洋西北部、加利福尼亚州、美国东部、阿拉斯加和巴西的气溶胶尺寸分布、化学成分、吸湿性生长因子、光散射效率、太阳辐射的后向散射和单一散射反照率。(B)在美国东海岸进行气溶胶“封柱”实验。根据对气溶胶的物理和化学性质的详细机载测量计算出的气溶胶对太阳辐射的影响，将与卫星对太阳辐射后向散射的测量进行比较，并与地面测量的太阳辐射衰减进行比较。

Hobbs/Abstract Aerosols may plan an important role in the radiation balance of the atmosphere on local, regional and global scales. Recent estimates suggest that the globally-averaged climate forcing due to the direct effects of anthropogenic sulfate could be similar in magnitude (but opposite in sign) to that produced by anthropogenic "greenhouse" gases. However, there are large uncertainties associated with estimating the aerosol effects. The purpose of this research is to obtain measurements on atmosphere aerosols (with emphasis on those that derive from anthropogenic sources) that will reduce these uncertainties. The proposed research consists of two main activities. (a) Measuring aerosol size distributions, chemical composition, hygroscopic growth factors, light-scattering efficiency, backscattering of solar radiation, and singlescattering albedos in the Pacific Northwest, California, the eastern United States, Alaska and Brazil. (b) Conducting an aerosol "column-closure" experiment off the east coast of the USA. Calculations of the effects of aerosols on solar radiation, based on detailed airborne measurements of the physical and chemical properties of the aerosols, will be compared with satellite measurements of the backscattering of solar radiation of ground-based measurements of the attenuation of solar radiation.