Importance of atmospheric aerosols through direct and indirect effects on hydrological cycle is highlighted through multiple studies. This study tries to find how much the aerosols can affect evapo-transpiration (ET), a key component of the hydrological cycle over high NDVI (normalized difference vegetation index)/dense canopy, over Dibrugarh, known for vast tea plantation. The radiative effects of aerosols are calculated using satellite (Terra-MODIS) and reanalysis data on daily and monthly scales. Aerosol optical depth (AOD) obtained from satellite and ground observations compares well. Aerosol radiative forcing (ARF), calculated using MERRA data sets of ‘clean-clear radiation’ and ‘clear-radiation’ at the surface, shows a lower forcing efficiency, 35 Wm^−zs, that is about half of that of ground observations. As vegetation controls ET over high NDVI area to the maximum and that gets modified through ARF, a regression equation is fitted between ET, AOD and NDVI for this station as ET = 0.25 + (−84.27) × AOD + (131.51) × NDVI that explains 82% of ‘daily’ ET variation using easily available satellite data. ET is found to follow net radiation closely and the direct relation between soil moisture and ET is weak on daily scale over this station as it may be acting through NDVI.

通过多项研究突出了通过对水文循环的直接和间接影响，大气气溶胶的重要性。这项研究试图找出在Dibrugarh上以高茶园闻名的高NDVI（归一化植被指数）/茂密冠层上，气溶胶蒸发（ET）是水文循环的关键组成部分的多少。使用卫星（Terra-MODIS）和再分析数据以日和月为单位计算气溶胶的辐射效应。从卫星和地面观测获得的气溶胶光学深度（AOD）进行了比较。使用表面“清洁辐射”和“清洁辐射”的MERRA数据集计算出的气溶胶辐射强迫（ARF）显示出较低的强迫效率，即35 Wm ^-zs，大约是地面观测值的一半。由于植被在最大NDVI区域上控制了ET的最大值，并通过ARF进行了修正，因此该站的ET，AOD和NDVI之间拟合了一个回归方程，因为ET = 0.25 +（−84.27）×AOD +（131.51）×NDVI使用容易获得的卫星数据解释了“日常” ET变化的82％。人们发现，ET紧随净辐射，并且在该站的日尺度上，土壤水分与ET之间的直接关系很弱，因为它可能通过NDVI起作用。