OPTICAL THICKNESS DATA: STAFF (FIFE)

Aerosol optical thickness in conjunction with an atmospheric model can provide estimates of atmospheric effects on transmitted and reflected solar radiation. These effects can then be used to correct aircraft and satellite radiometric data. In FIFE, three sunphotometers were used to track the sun through a range of airmasses during the period of February 6, 1987 through October 31, 1989. The Aerosol Optical Thickness from GSFC Data Set were analyzed using the Langley technique. Rayleigh optical depth was subtracted, and aerosol, ozone, and water vapor abundance's simultaneously measured. In retrieving ozone a Junge aerosol model was assumed, thus the natural log of aerosol optical depth was linear with wavelength (Bruegge et al. 1992). This approach allows measurement of aerosol, but is limited by the accuracy of the ozone data.气溶胶光学厚度（Aerosol Optical Thickness）结合大气模型，可用于估算大气对透射与反射太阳辐射的影响。此类大气影响可用于校正航空器及卫星的辐射测量数据。在FIFE实验中，研究人员于1987年2月6日至1989年10月31日期间，使用三台太阳光度计（sunphotometers）追踪不同大气质量数下的太阳辐射。针对GSFC数据集的气溶胶光学厚度，采用兰利法（Langley technique）开展分析。研究中扣除了瑞利光学厚度（Rayleigh optical depth），并同步测量了气溶胶、臭氧与水汽含量。在臭氧反演过程中，假设采用荣格气溶胶模型（Junge aerosol model），因此气溶胶光学厚度的自然对数与波长呈线性相关（Bruegge等，1992）。该方法可实现气溶胶的定量测量，但受限于臭氧数据的精度。