MERRA-2 Global Atmospheric Reanalysis with 3-Hourly Pressure-Level Assimilations

MERRA-2 inst3_3d_asm_Np provides instantaneous 3-dimensional assimilated meteorological fields at 42 pressure levels, produced by NASA's Global Modeling and Assimilation Office. The dataset offers 3-hourly global coverage from 1980 to the present, with a latency of approximately three weeks. NASA GMAO generated this reanalysis using the Goddard Earth Observing System Model version 5.12.4.

Use Cases

• Analyze temporal trends in temperature and water vapor across 42 pressure levels for climate change studies.
• Train spatiotemporal models to predict wind components and vertical pressure velocity from 3-hourly global snapshots.
• Validate atmospheric chemistry models using assimilated ozone mass mixing ratio fields.
• Study global atmospheric dynamics and energy transport using the comprehensive 3D assimilated state.
• Benchmark machine learning-based weather forecasting systems against this reanalysis product.

Strengths

• Covers a long temporal period from 1980 to present, enabling multi-decadal climate analysis.
• Provides data at 42 distinct pressure levels, offering detailed vertical atmospheric profiles.
• Delivers global coverage with a 0.625 x 0.5 degree spatial resolution.
• Features a high temporal resolution of 3-hourly instantaneous snapshots.

Limitations

• Data is a reanalysis product, not direct observations, subject to model biases and assimilation constraints.
• Has a known latency of approximately three weeks after the end of each month, limiting real-time use.
• The dataset's complexity and size require specialized knowledge and tools for effective processing.

Provenance

Source

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

Collection Method

Assimilated reanalysis generated 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.