Improvement of Aerosol Optical Depth Data for Localized Solar Resource Assessment

Chin-An Lin, Yimin Zhang, Garvin Heath, Daven Henze, Manajit Sengupta, Cheng-Hsuan Lu

Research output: Contribution to journalArticlepeer-review


Solar irradiance, especially for direct normal irradiance (DNI), is sensitive to the atmospheric aerosols, which can strongly extinguish DNI over areas with elevated aerosol loadings. The National Solar Radiation Database (NSRDB), developed by the National Renewable Energy Laboratory (NREL), uses AOD from MERRA-2 reanalysis and is further downscaled from 0.5° to 2-km based on elevation. However, the elevation-based downscaling may not accurately represent AOD, especially over the areas with large AOD gradients. This study examined whether the 1-km MODIS MAIAC satellite-retrieved AOD product can better represent the AOD distribution and be used to improve solar irradiance assessment. We focused on areas with relatively high AOD over North America (California, and New York City, US, and Mexico City in Mexico, in particular). The evaluation of MAIAC AOD and MERRA-2 AOD against ground-truth AERONET AOD shows that MAIAC AOD exhibits smaller RMSE by about 0.05 and higher correlation coefficient by 0.1–0.6 than MERRA-2 AOD. In addition, MERRA-2 AOD shows larger negative bias. The simulated DNI using MAIAC AOD (DNIMAIAC) and using MERRA-2 AOD (DNINSRDB) were evaluated with DNI observations. The results show the performance of DNIMAIAC is better than that of DNINSRDB with smaller RMSE by 0.5 - 1.5%, smaller positive mean bias by 0.8 - 3.1 % and comparable correlation for the 3 sites analyzed. Overall, 1-km MAIAC AOD shows higher accuracy than 2-km elevation-based MERRA-2 AOD, leading to better performance of the simulated DNI using MAIAC AOD. Therefore, 1-km MAIAC AOD can be used to improve the accuracy of solar resource assessment.

Original languageAmerican English
Pages (from-to)457-466
Number of pages10
JournalSolar Energy
StatePublished - 2023

Bibliographical note

Publisher Copyright:
© 2022 The Authors

NREL Publication Number

  • NREL/JA-6A20-79784


  • Aerosol optical depth
  • Direct normal irradiance
  • Solar irradiance
  • Solar resource assessment


Dive into the research topics of 'Improvement of Aerosol Optical Depth Data for Localized Solar Resource Assessment'. Together they form a unique fingerprint.

Cite this