National Aeronautics and Space Administration

Introduction

The GEOS-IT product is a stable meteorological dataset that is generated for NASA’s Instrument Teams. Like the GEOS-RPIT/FPIT dataset that it replaces, GEOS-IT begins at the time of NASA’s EOS mission (in 1998) up to the present day, when it will be produced and distributed in near-real time.

GEOS-IT retains many characteristics of GEOS-FPIT, including the spatial resolution (about 50km) and the use of a three-dimensional variational data assimilation algorithm. It allows the instrument teams to benefit from many model enhancements, leading to more realistic representations of moisture, temperature, land surface, etc., and analysis changes that introduce the most modern new satellite observations into the system. GEOS-IT uses the GEOS-5.27.1 assimilation system that was used with a different configuration (including higher resolution) as the GEOS-FP system, beginning in February 2021.

The system has been run for a limited period to produce a sample dataset (for 2018) that is now available to the user community for evaluation, testing and feedback.

• Questions about GEOS-IT may be sent to robert.a.lucchesi@nasa.gov.