We are pleased to announce the release of the Modern-Era Retrospective analysis for Research and Applications – 2 (MERRA-2) Stratospheric Composition Reanalysis of Aura Microwave Limb Sounder (M2-SCREAM) developed at NASA’s Global Modeling and Assimilation Office in collaboration with the Microwave Limb Sounder (MLS) team.

This stratosphere-focused chemical reanalysis provides assimilated global three-dimensional fields of ozone, water vapor, hydrogen chloride (HCl), nitric acid (HNO3), and nitrous oxide (N2O) mixing ratios, all of which are of primary importance to stratospheric chemistry and transport studies. M2-SCREAM assimilates MLS profile observations of these five species, alongside total ozone data from the Ozone Monitoring Instrument, with the recently developed Constituent Data Assimilation System (CoDAS). The system configuration includes a stratospheric chemistry module, StratChem and a version of the GEOS global circulation model with the dynamics constrained by meteorological fields from MERRA-2. The assimilated output is provided at a 50-km horizontal resolution on 72 model layers and at a three-hourly frequency. Analysis uncertainties are provided in a separate monthly data collection. A description and validation manuscript has been submitted to Earth System Science Data.

The current release covers the period from October 2004 to December 2021. Periodic updates are planned for the remainder of the MLS mission.

The M2-SCREAM data are available to the public through the Goddard Earth Sciences Data and Information Services Center (GES DISC) and can be accessed here.

A longer release statement can be found here.