MERRA-2 Hourly Atmospheric Diagnostics at Single Levels

MERRA-2 provides an hourly, global atmospheric reanalysis from 1980 to the present. The M2I1NXASM collection contains instantaneous assimilations of meteorological parameters like 2-meter temperature, 10-meter wind components, surface pressure, and total precipitable water. NASA's Global Modeling and Assimilation Office produces this data using the Goddard Earth Observing System Model.

Use Cases

• Analyze long-term trends in near-surface air temperature using the 2-meter temperature parameter.
• Model surface wind patterns and energy potential using the 10-meter and 50-meter wind component data.
• Study atmospheric moisture content and its variability with the total precipitable water field.
• Validate numerical weather prediction models against assimilated surface pressure observations.
• Correlate hourly meteorological conditions with other environmental datasets using the consistent 0.625x0.5 degree global grid.

Strengths

• Global spatial coverage at a 0.625x0.5 degree resolution.
• Temporal coverage spans from 1980 to the present, providing over 40 years of data.
• Hourly timestamps enable analysis of diurnal cycles and short-term phenomena.
• Produced by NASA's Global Modeling and Assimilation Office using a consistent assimilation system.

Limitations

• Data has an approximate latency of 3 weeks after the end of each month, limiting real-time analysis.
• As a reanalysis product, it represents a model assimilation and not direct observations, which may contain biases.
• Reprocessing events can create multiple file versions with different names, requiring careful version management.

Provenance

Source

NASA Global Modeling and Assimilation Office (GMAO) via the GES DISC.

Collection Method

Assimilation of observational data using the Goddard Earth Observing System Model (GEOS) version 5.12.4.

Time Range

1980 to present

Freshness

Updated monthly with a ~3 week latency.

Geography

Global