Arctic Winter 2025-26 Synergistic Dataset with PREFIRE, MERRA-2 Reanalysis, and EarthCARE Products

The synergistic collocation of the PREFIRE, MERRA-2 Reanalysis, and EarthCARE datasets provides novel opportunities to analyze the radiative effects of clouds and aerosols in the Arctic. This dataset has a spatial resolution of approximately 700 m, which is the same as the spatial resolution of EarthCARE’s CPR. This dataset also contains the inputs or the requirements to derive inputs for a radiative transfer model. ESA/JAXA EarthCARE launched in 2024 with the mission to improve climate and weather forecasts. Of the four instruments on board, the 355 nm Atmospheric Lidar (ATLID) and 94 GHz Cloud Profile Radar (CPR) provide this dataset with extinction, backscatter, and depolarization (EBD) and nominal 1B data, respectively. NASA PREFIRE CubeSats were also launched in 2024, intending to measure far-infrared (FIR) radiation at the poles to reduce uncertainty of Arctic clouds in the global radiation budget. Each of the two CubeSats provides pushbroom longwave spectral radiometry measurements, ranging from 5 to 54 microns with a resolution of approximately 0.84 microns. Finally, the NASA GMAO MERRA-2 Reanalysis provides hourly global gridded aerosol-considered thermodynamic and aerosol mixing ratio data. At the time of publishing, MERRA-2 does not assimilate EarthCARE nor PREFIRE data. For more methodology and variable information, consult the README.md document. The data files are in a .nc4 format, with the following naming conventions: arctic_earthcare_prefire_merra2_YYYYMMDDTHHmmSS_vN, where YYYY is the four-digit year, MM is the two-digit month, DD is the two-digit day, HH is the two-digit hour, mm is the two-digit minute, SS is the two-digit seconds, and N is the version number. The datetimes are taken from the middle of the EarthCARE/PREFIRE collocation period. Source data acknowledgments:This dataset contains collocated and processed data derived from PREFIRE, EarthCARE, and MERRA-2 products. Original datasets are provided by NASA and ESA/JAXA and remain subject to their respective data-use policies.