Two decades of aerosol observations by AATSR, MISR, MODIS and MERRA-2 over India and Indian Ocean

REMOTE SENSING OF ENVIRONMENT

卷:257

Article

Kuttippurath, J.¹  Raj, S.¹ 

[1] Indian Inst Technol Kharagpur, CORAL, Kharagpur 721302, W Bengal, India

关键词: Climate change;    Remote sensing;    MISR;    MODIS;    AATSR;    MERRA;    Aerosols;    India;    Indian Ocean;   

DOI  :  10.1016/j.rse.2021.112363

来源: Elsevier

【 摘 要 】

Atmospheric aerosols play key roles in radiation budget, ecosystem dynamics, air quality and cloud microphysics of a region and thus, they greatly influence the global climate, ecosystem and public health. We present the temporal variability of atmospheric aerosols over India and north Indian Ocean (NIO) for the past two decades (2000?2019). Here, the measurements from Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra, Multi-angle Imaging Spectroradiometer (MISR) on Terra, and Advanced Along Track Scanning Radiometer (AATSR) measurements from Envisat, and Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) reanalysis data are considered. On average, the Indo Gangetic Plain (IGP) shows the largest (0.5?1.2), and NIO and Himalaya show the smallest (0.1 or smaller) Aerosol Optical depth (AOD) values. The peak AOD loading is observed in June?July-August, and IGP has a secondary peak in March owing to the stubble and biomass burning in winter months. In contrast, the peak aerosol loading in the northeast is in winter due to forest and biomass burning during the period there. The inter-annual variability is very small in NIO, Himalaya and Bay of Bengal. The trends estimated from the combined (AATSR, MISR, MODIS and MERRA-2) data show the highest positive trends at the lower IGP and east central regions, about 0.8?1.2/dec, and are statistically significant. This is consistent with the urban activity, industries and dense population there. However, the Desert, northern Himalaya and northern Arabian Sea show insignificant negative trends, from-0.2 to-0.4/dec, as the anthropogenic sources of aerosols are very limited there. The bias estimate shows that most satellite and reanalysis data are in very good agreement at all regions (within 0.1?0.2). Even though the bias in the measurements are considered, the trends estimated are still large enough to be statistically significant. The analyses, therefore, caution the increasing aerosol loading and their plausible climate feedback in these regions. The assessment also demonstrate the potential of synergetic use of multiple-platform measurements for climate system studies.

【 授权许可】

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