Monthly Cloud Diagnostics on Pressure Levels from NASA MERRA-2 Reanalysis

MERRA-2 provides a 3D monthly mean assimilation of cloud diagnostics across 42 pressure levels, including updraft areal fraction and in-cloud liquid water mass. This dataset is produced by NASA's Global Modeling and Assimilation Office using the GEOS model and covers the period from 1980 to the present, with a latency of approximately three weeks.

Use Cases

• Analyze the vertical profile of cloud fraction for radiation across 42 pressure levels to improve climate model accuracy.
• Study the relationship between updraft areal fraction and convective cloud formation in reanalysis data.
• Validate satellite-derived cloud liquid water mass estimates using the assimilated in-cloud cloud liquid for radiation field.
• Investigate long-term trends in cloud ice mass fraction for radiation from 1980 to present.
• Use variance parameters to assess uncertainty in monthly mean cloud diagnostic estimates.

Strengths

• Covers a continuous period from 1980 to present, providing over 40 years of data.
• Provides assimilated data on 42 distinct pressure levels for detailed vertical analysis.
• Produced by NASA's GMAO using the authoritative GEOS version 5.12.4 model.

Limitations

• Specific sample sizes, row counts, and data volumes are not provided in the description.
• Data is reprocessed, requiring users to check for version changes and filename differences.
• Has a known latency of approximately three weeks after the end of each month.

Provenance

Source

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

Collection Method

Assimilation of observational data into 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 coverage at a 0.625 x 0.5 degree resolution.