method in order to fill gaps in observational data. 102. Earth system reanalysis (a) In general Not later than two years after the date of the enactment of this Act, the Administrator shall, in consultation with the Secretary of Energy, the Administrator of the National Aeronautics and Space Administration, the Director of the National Science Foundation, the Director of the National Center for Atmospheric Research, the Environmental Information Services Working Group, and such other technical experts as the Administrator considers appropriate, develop and curate an Earth system reanalysis dataset that creates a long-term record of past weather in support of— (1) furthering the understanding of weather