Global Atmospheric Reanalysis at 42 Pressure Levels

MERRA-2 provides a global atmospheric reanalysis from 1980 to present, produced by NASA's Global Modeling and Assimilation Office. The M2I6NPANA collection contains instantaneous 3D meteorological fields at 42 pressure levels, sampled every six hours. This dataset is generated using the Goddard Earth Observing System Model version 5.12.4.

Use Cases

• Analyze vertical atmospheric profiles by comparing temperature and specific humidity across the 42 pressure levels.
• Model global wind patterns using the u and v wind component fields at six-hourly intervals.
• Study stratospheric ozone transport and distribution using the ozone mixing ratio field.
• Calculate geopotential height gradients to investigate pressure systems and atmospheric waves.
• Validate other climate reanalysis products by comparing time-series of analyzed meteorological fields from 1980 onward.

Strengths

• Covers a continuous time range from 1980 to the present, enabling long-term trend analysis.
• Provides data at 42 distinct pressure levels for detailed vertical atmospheric structure.
• Offers global spatial coverage with a 0.625 x 0.5 degree latitude/longitude grid.
• Maintained by NASA GMAO with documented reprocessing records for version control.

Limitations

• Data has an approximate latency of three weeks after the end of each month, limiting real-time applications.
• Spatial resolution of about 50-60 km may be too coarse for mesoscale or local weather studies.

Provenance

Source

NASA Global Modeling and Assimilation Office (GMAO)

Collection Method

Produced via the Goddard Earth Observing System Model (GEOS) version 5.12.4, assimilating satellite and observational data.

Time Range

1980 - Present

Freshness

Updated monthly with a ~3-week latency.

Geography

Global