Evaluation of the ability of radiation transmission model and MODIS images to estimate aerosol optical depth

Document Type : Original Article

Authors

1 M.Sc of Marine Environmental, College of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr , Iran

2 Assistant Professor College of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.

3 Associate Professor College of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr , Iran

4 Professor, College of Agriculture, Shiraz University, Shiraz, Iran. 5. Lecturer, College of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr , Iran

5 Lecturer, College of Marine Natural Resources, Khorramshahr University of Marine Science and Technology, Khorramshahr , Iran.

Abstract

Aerosols play an important role in the climate system of the atmosphere. These atmospheric particles are directly affected by changing radiation exposure by diffusing and absorbing different wavelengths and indirectly by changing the optical properties and the durability of the clouds, and the optical properties of the aerosols, such as aerosols optical depth (AOD), are critical in understanding the effects of atmospheric aerosols on climate change and biogeochemical cycles. Therefore, in this research, the ability of radiation transmission model and MODIS images was evaluated to estimate the aeroeses optical depth in Persian Gulf. MATLAB was used for images processing of the images with resolution of 500 m at 5×5 networks. The evaluation of aerosoles optical depth data was performed by using AERONET stations with Pearson correlation, RMSE and RMSD indices. First results of the algorithm implementation showed the ability of model to simulate the aerosols optical depth. Modeling results showed that the algorithm is correct and according to spectral reflectance data for effective radius of the LUT tables, values simulated for aerosols optical depth. The results of evaluation showed that optical depth values obtained from the images has significantly correlation with the measured optical depth in AERONET stations. So that, amount of correlation calculated form 29 June 2013, 14 July 2014 and 6 October 2015 in the band of 1.243  is 0.96, 0.94 and 0.98 respectively, and for the band of 1.643  is 0.99, 0.98 and 0.98, respectively which shows a good trend between the measured data, RMSE and RMSD indices were calculated in these days less than 0.15 and less than 0.06, respectively. It can be concluded that simulations accuracy is appropriate in these bands.

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