MERRA-2 3-Hourly Atmospheric Radiation Diagnostics at 72 Model Layers

MERRA-2 M2T3NVRAD provides 3-dimensional, 3-hourly time-averaged assimilated radiation diagnostics across 72 atmospheric model layers. NASA's Global Modeling and Assimilation Office produced this dataset using the GEOS model, covering the period from 1980 to the present with approximately three weeks latency. Variables include air temperature tendencies due to longwave and shortwave radiation.

Use Cases

• Analyze diurnal cycles of radiative heating by examining air temperature tendency due to shortwave across the 72 model layers at 3-hourly intervals.
• Validate climate model radiation schemes by comparing simulated longwave radiation diagnostics against this reanalysis data.
• Study vertical profiles of atmospheric energy balance using assimilated radiation fields at specific pressure levels defined in the file specification.
• Investigate trends in radiative forcing from 1980 to present using the time series of assimilated radiation diagnostics.

Strengths

• Continuous temporal coverage from 1980 to present, providing over 40 years of data.
• High vertical resolution with diagnostics provided at 72 distinct model layers.
• Frequent 3-hourly time averaging, capturing diurnal cycles starting at 01:30 UTC.

Limitations

• Data has a latency of approximately three weeks after the end of a month, limiting real-time analysis.
• Spatial resolution is 0.625 by 0.5 degrees, which may be coarse for regional-scale studies.
• Potential inconsistencies exist due to documented data reprocessing events, requiring filename checks.

Provenance

Source

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

Collection Method

Produced by the Goddard Earth Observing System Model (GEOS) version 5.12.4 through atmospheric reanalysis, assimilating observational data.

Time Range

1980 to present.

Freshness

Updated monthly with ~3-week latency.

Geography

Global coverage at 0.625 x 0.5 degree resolution.