Retrieval and Evaluation of Maritime AOD and PWV from Ship‐Based Microtops II Sun Photometers and Their Seasonal Variability Using MODIS Measurements Over the Indonesian Throughflow Region

Aerosol optical depth (AOD) and precipitable water vapor (PWV) are two very important physical parameters for characterizing aerosols. The measurements of maritime AOD and PWV content improve our understanding of the atmospheric properties over the oceans. This study validated maritime AOD and PWV data during RV Baruna Jaya VIII Cruise expedition obtained from the ship-based Microtops II Sun Photometer in Indonesian Throughflow Region with coastal AERONET data and observed their seasonal variability over 22 years by utilizing MODIS collection 6 data. The results showed that the AOD had RMSE values ranging from 0.05 to 0.10, MAE values ranging from 0.04 to 0.09, MAPE values ranging from 22.63 to 27.30%, and R2 values ranging from 0.45 to 0.83. From 340 to 870 nm, the larger the AOD wavelength value, the smaller the RMSE, MAE, and R2 value. Meanwhile, the RMSE, MAE, MAPE, and R2 values of PWV were 1.44 cm, 1.41 cm, 32.41%, and 0.65, respectively. The seasonal variability of AOD (470 and 550 nm) and PWV showed that the highest average value occurs in the pre-monsoon period (September–October–November period) and the lowest occurred in the March–April–May period.