Earth Data School
About
Full catalog/M2TMNXRAD
M2TMNXRAD·v5.12.4·dataset

Monthly sunlight and heat radiation model (MERRA-2)

MERRA-2 tavgM_2d_rad_Nx: 2d,Monthly mean,Time-Averaged,Single-Level,Assimilation,Radiation Diagnostics 0.625 x 0.5 degree V5.12.4 (M2TMNXRAD) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Monthly averages of radiation-related conditions worldwide, such as how reflective the surface is, cloud cover, incoming and outgoing solar and heat energy, and related figures.

How it's made. Not a direct measurement but the output of MERRA-2, a NASA model that blends decades of satellite observations into a consistent reconstruction of the atmosphere, delivered on a roughly half-degree grid.

How & where you'd use it. Useful for climate research, energy-balance studies, and providing a long, consistent record of Earth's radiation back to 1980.

What's measured

ATMOSPHERE › ATMOSPHERIC RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › LONGWAVE RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › SHORTWAVE RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › RADIATIVE FLUXATMOSPHERE › ATMOSPHERIC RADIATION › RADIATIVE FORCINGLAND SURFACE › SURFACE RADIATIVE PROPERTIESLAND SURFACE › SURFACE RADIATIVE PROPERTIES › ALBEDOLAND SURFACE › SURFACE RADIATIVE PROPERTIES › EMISSIVITYATMOSPHERE › CLOUDS › CLOUD PROPERTIESATMOSPHERE › CLOUDS › CLOUD PROPERTIES › CLOUD FRACTIONATMOSPHERE › CLOUDS › CLOUD MICROPHYSICS › CLOUD OPTICAL DEPTH/THICKNESSATMOSPHERE › ATMOSPHERIC TEMPERATURE › SURFACE TEMPERATURE › SKIN TEMPERATURELAND SURFACE › SURFACE THERMAL PROPERTIES › SKIN TEMPERATUREOCEANS › OCEAN TEMPERATURE › SEA SURFACE TEMPERATURE › SEA SURFACE SKIN TEMPERATURE

Coverage & cadence

  • Time span1980-01-01 → ongoing
  • Measured byMERRA-2 (NOT APPLICABLE)
  • Processing levelLevel 4
  • Spatial extent-180, -90, 180, 90
  • StatusACTIVE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

M2TMNXRAD (or tavgM_2d_rad_Nx) is a time-averaged 2-dimensional monthly mean data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of radiation diagnostics, such as surface albedo, cloud area fraction, in cloud optical thickness, surface incoming shortwave flux (i.e. solar radiation), surface net downward shortwave flux, and upwelling longwave flux at toa (top of atmosphere) (i.e. outgoing longwave radiation (OLR) at toa). The collection also includes variance of certain parameters. MERRA-2 is the latest version of global atmospheric reanalysis for the satellite era produced by NASA Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System Model (GEOS) version 5.12.4. The dataset covers the period of 1980-present with the latency of ~3 weeks after the end of a month. Data Reprocessing: Please check “Records of MERRA-2 Data Reprocessing and Service Changes” linked from the “Documentation” tab on this page. Note that a reprocessed data filename is different from the original file. MERRA-2 Mailing List: Sign up to receive information on reprocessing of data, changing of tools and services, as well as data announcements from GMAO. Contact the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov) to be added to the list. Questions: If you have a question, please read "MERRA-2 File Specification Document", “MERRA-2 Data Access – Quick Start Guide”, and FAQs linked from the ”Documentation” tab on this page. If that does not answer your question, you may post your question to the NASA Earthdata Forum (forum.earthdata.nasa.gov) or email the GES DISC Help Desk (gsfc-dl-help-disc@mail.nasa.gov).

Get the data

m2tmnxrad_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2TMNXRAD",
    version="5.12.4",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.