MERRA-2 Global Atmospheric Reanalysis at 42 Pressure Levels

MERRA-2 instU_3d_asm_Np provides instantaneous 3D assimilated meteorological fields at 42 pressure levels. NASA's Global Modeling and Assimilation Office produced this global atmospheric reanalysis using the GEOS model, covering the period from 1980 to the present with a latency of approximately three weeks. The collection consists of monthly diurnal means calculated from data sampled every three hours.

Use Cases

• Analyze temperature and wind component trends across 42 pressure levels to study atmospheric dynamics.
• Model vertical pressure velocity and water vapor for climate change impact assessments.
• Validate ozone mass mixing ratio predictions from other models using this assimilated reanalysis data.
• Study diurnal cycles by comparing assimilated fields from the 00:00, 03:00, ..., 21:00 UTC time slices.
• Correlate layer height data with other satellite-era observations for atmospheric research.

Strengths

• Global spatial coverage at 0.625 x 0.5 degree resolution.
• Continuous temporal coverage from 1980 to present, spanning over 40 years.
• Contains assimilated data for multiple key meteorological parameters across 42 pressure levels.

Limitations

• Data is a reanalysis product, not direct observation, subject to model biases and assimilation system errors.
• Latency of ~3 weeks after month-end limits near-real-time applications.
• Potential inconsistencies exist due to documented data reprocessing events, indicated by filename changes.

Provenance

Source

NASA Global Modeling and Assimilation Office (GMAO) via the Goddard Earth Sciences Data and Information Services Center (GES DISC).

Collection Method

Assimilated reanalysis produced using the Goddard Earth Observing System Model (GEOS) version 5.12.4.

Time Range

1980 - Present

Freshness

Updated monthly with a ~3 week latency.

Geography

Global