Validation of MODIS C6.1 and MERRA-2 AOD Using AERONET Observations: A Comparative Study over Turkey

Abstract

This study validated MODIS (Moderate Resolution Imaging Spectroradiometer) of the National Aeronautics and Space Agency, USA, Aqua and Terra Collection 6.1, and MERRA-2 (Modern-ERA Retrospective Analysis for Research and Application) Version 2 of aerosol optical depth (AOD) at 550 nm against AERONET (Aerosol Robotic Network) ground-based sunphotometer observations over Turkey. AERONET AOD data were collected from three sites during the period between 2013 and 2017. Regression analysis showed that overall, seasonally and daily statistics of MODIS are better than MERRA-2 by the mean of coefficient of determination (R2), mean absolute error (MAE), and relative root mean square deviation (RMSDrel). MODIS combined Terra/Aqua AOD and MERRA-2 AOD corresponding to morning and noon hours resulted in better results than individual sub datasets. A clear annual cycle in AOD was detected by the three platforms. However, overall, MODIS and MERRA-2 tend to overestimate and underestimate AOD, respectively, in comparison with AERONET. MODIS showed higher efficiency in detecting extreme events than MERRA-2. There was no clear relation found between the accuracy in MODIS/MERRA-2 AOD and surface relative humidity (RH).

Impacts of COVID-19 on Air Quality over China: Links with Meteorological Factors and Energy Consumption

“…3 and 4. Some studies (e.g., Penna et al, 2018;Aldabash et al, 2020) have shown that MODIS and MERRA-2 AODs are consistent in terms of temporal variation; however, MODIS AODs can be higher than MERRA-2 values. The study sectors described in Section 2 were further divided into highly populated (>1 million) and moderately or less populated (<1 million) regions to calculate their mean AODs (Table 1).…”

Winter AOD trend changes over the Eastern Mediterranean and Middle East region

“…Over the past years, various reanalysis and satellite datasets have provided global aerosol data products, such as the Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA‐2), and the MODerate resolution Imaging Spectroradiometer (MODIS). Numerous studies have used the Aerosol Robotic Network (AERONET) data to evaluate the MERRA‐2 and MODIS AODs over the Middle East region and very good agreement has been reported between AODs from these platforms (Sabetghadam et al ., 2018, 2021; Che et al ., 2019; Aldabash et al ., 2020; Shaheen et al ., 2020; Yousefi et al ., 2020a).…”

Multiple site ground-based evaluation of carbonaceous aerosol mass concentrations retrieved from CAMS and MERRA-2 over the Indo-Gangetic Plain

“…Earlier, several authors have reported the assessment of CAMSRA and/or MERRA-2 simulated aerosol optical depth with the AERONET observations. (28)(29)(30)(31) At the same time, limited studies have stated the association of reanalysis data of aerosol mass concentrations with ground-based observations. (32) Previously, Buchard et al (33) reported the comparison of ground-based aerosol mass concentrations measured from approximately 300 sites across the United States with MERRA (version 1) reanalysis data.…”