MERRA-2¶

Global atmospheric reanalysis dataset produced by NASA Global Modeling and Assimilation Office (GMAO), providing physically consistent meteorological fields for weather, climate, and hazard modeling.

Overview¶

MERRA-2 (Modern-Era Retrospective analysis for Research and Applications, Version 2) is a global atmospheric reanalysis that assimilates satellite and conventional observations into a numerical weather prediction system to produce gridded, time-continuous estimates of the atmospheric state.

It is widely used as a core meteorological driver in climate analysis and hazard prediction pipelines, including wildfire, hurricane, drought, and extreme heat studies.

Data Characteristics¶

Spatial coverage: Global
Spatial resolution: ~0.5° latitude × 0.625° longitude
Temporal resolution: Hourly
Vertical structure: Surface fields and multi-level pressure profiles
Data format: NetCDF
Coordinate system: Regular latitude–longitude grid

Variables¶

MERRA-2 provides a broad set of atmospheric and land-surface variables, including but not limited to:

Near-surface meteorology (2 m temperature, humidity, wind)
Surface energy fluxes and precipitation
Atmospheric pressure-level variables (temperature, winds, geopotential height)
Land-surface states (soil moisture, skin temperature)

Typical Use Cases¶

Meteorological forcing for wildfire and natural hazard prediction models
Climate diagnostics and long-term trend analysis
Environmental covariates for spatiotemporal machine learning models
Benchmark reanalysis input for weather–climate pipelines (e.g., WxC-style workflows)

Access¶

MERRA-2 data can be accessed via NASA GMAO and Earthdata services:

Reference¶

Gelaro, R., McCarty, W., Suárez, M. J., et al. (2017). The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2). Journal of Climate, 30(14), 5419–5454. https://doi.org/10.1175/JCLI-D-16-0758.1