LaGA aerosol dataset: a high-accuracy, long-term, stable, and continuous total and fine-mode aerosol record retrieved from MODIS to VIIRS

The LaGA dataset is constructed based on observation data from two MODIS sensors onboard Terra and Aqua satellites and two VIIRS sensors onboard SNPP and NOAA20 satellites. It provides aerosol retrievals from 2000 to 2023, including three parameters: AOD, FMF, and AODF. Since four instruments are operating simultaneously, the temporal resolution is better than 1‒4 times per day in the clear sky, depending on the satellite mission overlap period. Its spatial resolution is consistent with MODIS and VIIRS aerosol products operated by NASA and NOAA, 5‒6 minutes orbit level, 6 km for VIIRS, and 10 km for MODIS. The orbital-level data is also called Level-2 data according to NASA's command rules. Level-2 data does not have geographic projection coordinates but provides pixel-by-pixel latitude and longitude data to facilitate geographic correction.For the convenience of users, the orbital-level data are synthesized into daily composites, monthly means, and annual means. Annual medians, standard deviations, and synthesized pixel counts are also provided. The retrievals for each instrument were calculated separately. They are provided in 0.1° (~10 km) and 1° (~100 km) gridded data with global coverage and in the WGS-84 coordinate system. All the data are stored losslessly compressed in GeoTIFF and HDF5 formats with metadata. The data values of all products are provided as actual physical quantities (unitless), so no additional numerical scaling is required. Note that LaGA datasets provide full-quality retrieval and high-quality retrieval, and high-quality retrieval is recommended. The files are named according to the observational date. Tables below summarizes the characteristics of the LaGA aerosol products and the data variables stored in the dataset. The figure below shows the flowchart of the LaGA dataset production.