Optical characteristics of the aerosol in Spain and Austria and its effect on radiative forcing -: art. no. 4386
Optical characteristics of the aerosol in Spain and Austria and its effect on radiative forcing -: art. no. 4386
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DOI：
10.1029/2001jd001472
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发表时间：
2002-09-01
影响因子：
4.4
通讯作者：
Seidl, S
中科院分区：
文献类型：
--
作者：
Horvath, H;Arboledas, LA;Seidl, S
[1]气溶胶的水平和垂直衰减，天空辐射，气溶胶的光吸收系数已被确定在可见光波长。从这组数据可以得到以下的大气气溶胶的光学特性：垂直光学厚度，水平消光系数和吸收系数，散射相函数，不对称参数，和单次散射的消光系数。在西班牙的阿尔梅里亚和奥地利的维也纳开展了宣传活动。正如许多其他研究所经历的那样，气溶胶经历了相当大的变化。有时垂直和水平测量得到的数据相似;在其他日子里，表面的气溶胶和高空的气溶胶完全不同。“最清晰”的气溶胶总是具有最小的单次散射，因此相对来说光吸收最高。在两个非常不同的位置，气溶胶的光学特性非常相似。使用测量的光学数据，进行辐射传输计算，并计算到达地面的辐射。通过比较晴空气溶胶和气溶胶高负荷日的数值，可以确定附加气溶胶粒子的辐射强迫。地面气溶胶的强迫总是为负，而在大气层顶部，它接近于零或略负。给出了它与波长和天顶角的关系。对欧洲工业化前的气溶胶进行了估算，并确定了现今气溶胶的强迫。在地表，它是负的，但在大气层的顶部，它接近于零或正。这是由于欧洲气溶胶的光吸收率高于大多数其他地区。
[1] The horizontal and vertical attenuation of the aerosol, the sky radiance, and the light absorption coefficient of the aerosol have been determined at wavelengths in the visible. From this set of data the following optical characteristics of the atmospheric aerosol could be derived: vertical optical depth, horizontal extinction and absorption coefficient, scattering phase function, asymmetry parameter, and single scattering albedo. Campaigns have been performed in Almeria, Spain, and Vienna, Austria. The aerosol undergoes a considerable variation, as experienced by many other studies. Sometimes the vertical and the horizontal measurements gave similar data; on other days the aerosol at the surface and the aerosol aloft were completely different. The "clearest'' aerosol always had the smallest single scattering albedo and thus relatively the highest light absorption. The optical characteristics of the aerosol in the two very different locations were very similar. Using the measured optical data, a radiative transfer calculation was performed, and the radiation reaching the ground was calculated. Comparing the values for the clear aerosol and the days with higher aerosol load, the radiative forcing due to the additional aerosol particles could be determined. The forcing of the aerosol at the ground is always negative, and at the top of the atmosphere it is close to zero or slightly negative. Its dependence on wavelength and zenith angle is presented. The preindustrial aerosol in Europe was estimated, and the forcing due to the present-day aerosol was determined. At the surface it is negative, but at the top of the atmosphere it is close to zero or positive. This is caused by the light absorption of the European aerosol, which is higher than in most other locations.