Earth Data School
About
Full catalog/M2T3NVRAD
M2T3NVRAD·v5.12.4·dataset

Modeled radiation through the atmosphere, every 3 hours (MERRA-2)

MERRA-2 tavg3_3d_rad_Nv: 3d,3-Hourly,Time-Averaged,Model-Level,Assimilation,Radiation Diagnostics 0.625 x 0.5 degree V5.12.4 (M2T3NVRAD) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Modeled details about how radiation heats and cools the air at 72 stacked layers of the atmosphere, given every three hours. It includes how much each layer's temperature is changing due to longwave (heat) and shortwave (sunlight) radiation.

How it's made. Produced by NASA's MERRA-2 reanalysis, which blends decades of satellite observations into the GEOS atmospheric model rather than coming straight from one instrument.

How & where you'd use it. A reference for researchers studying the atmosphere's energy balance and how radiation drives temperature changes through its layers.

What's measured

ATMOSPHERE › ATMOSPHERIC PRESSURE › PRESSURE THICKNESSATMOSPHERE › ATMOSPHERIC PRESSURE › SURFACE PRESSUREATMOSPHERE › ATMOSPHERIC RADIATIONATMOSPHERE › CLOUDS › CLOUD PROPERTIES › CLOUD FRACTION

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

M2T3NVRAD (or tavg3_3d_rad_Nv) is a 3-dimensional 3-hourly time averaged data collection in Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2). This collection consists of assimilated radiation diagnostics at 72 model layers, such as air temperature tendency due to longwave and air temperature tendency due to shortwave. The data field is available every three hour starting from 01:30 UTC, e.g.: 01:30, 04:30, … , 22:30 UTC. Section 4.2 of the MERRA-2 File Specification document provides pressure values nominal for a 1000 hPa surface pressure and refers to the top edge of the layer. The lev=1 is for the top layer, and lev=72 is for the bottom (or surface) model layer. 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

m2t3nvrad_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2T3NVRAD",
    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.