Intercomparison of Aerosol Optical Thickness Derived from MODIS and in Situ Ground Datasets over Jaipur, a Semi-arid Zone in India

摘要

The first detailed seasonal validation has been carried out for the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua satellites Level 2.0 Collection Version S.I AOT (τ_(MODIS)) with Aerosol Robotic Network (AERONET) Level 2.0 AOT (τ_(AERONET)) for the years 2009-2012 over semi-arid region Jaipur, northwestern India. The correlation between τ_(MODIS) versus τ_(AERONET) at 550 nm is determined with different spatial and temporal size windows. The τ_(MODIS) overestimates τ_(AERONET) within a range of +0.06 ± 0.24 during the pre-monsoon (April-June) season, while it underestimates the τ_(AERONET) with -0.04 ± 0.12 and - 0.05 ± 0.18 during dry (December-March) and post-monsoon (October-November) seasons, respectively. Correlation without (with) error envelope has been found for pre-monsoon at 0.71 (0.89), post-monsoon at 0.76 (0.94), and dry season at 0.78 (0.95). τmodis is compared to τ_(AERONET) at three more ground AERONET stations in India, i.e., Kanpur, Gual Pahari, and Pune. Furthermore, the performance of MODIS Deep Blue and Aqua AOT_(550nm) (τ_(DB550nm) and τ_(Aqua550nm)) with τ_(AERONET) is also evaluated for all considered sites over India along with a U.S. desert site at White Sand, Tularosa Basin, NM. The statistical results reveal that τ_(Aqua550nm) performs better over Kanpur and Pune, whereas τ_(DB550nm) performs better over Jaipur, Gual Pahari, and White Sand High Energy Laser Systems Test Facility (HELSTF) (U.S. site).