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Full catalog/M2TMNXAER
M2TMNXAER·v5.12.4·dataset

Airborne dust, smoke and haze, monthly average (MERRA-2)

MERRA-2 tavgM_2d_aer_Nx: 2d,Monthly mean,Time-averaged,Single-Level,Assimilation,Aerosol Diagnostics 0.625 x 0.5 degree V5.12.4 (M2TMNXAER) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Monthly averages of tiny airborne particles worldwide, broken down by type: black carbon and organic carbon from burning, mineral dust, sea salt, and sulfate. It also captures how much these particles dim and scatter sunlight.

How it's made. Comes from MERRA-2, a NASA computer model that blends satellite observations with weather modeling to reconstruct conditions back to 1980; this file holds monthly averages on a roughly half-degree grid.

How & where you'd use it. Useful for studying air quality, haze, and dust over time, and for deriving particle-pollution measures like PM2.5 to understand health and climate impacts.

What's measured

ATMOSPHERE › AEROSOLSATMOSPHERE › AEROSOLS › AEROSOL EXTINCTIONATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESSATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESS › ANGSTROM EXPONENTATMOSPHERE › AEROSOLS › AEROSOL PARTICLE PROPERTIESATMOSPHERE › AEROSOLS › CARBONACEOUS AEROSOLSATMOSPHERE › AEROSOLS › DUST/ASH/SMOKEATMOSPHERE › AEROSOLS › ORGANIC PARTICLESATMOSPHERE › AEROSOLS › SULFATE PARTICLESATMOSPHERE › AIR QUALITY › SULFUR OXIDESATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDSATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDS › SULFATEATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDS › SULFUR DIOXIDEATMOSPHERE › ATMOSPHERIC CHEMISTRY › SULFUR COMPOUNDS › SULFUR OXIDES

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

M2TMNXAER (or tavgM_2d_aer_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 assimilated aerosol diagnostics, such as column mass density of aerosol components (black carbon, dust, sea salt, sulfate, and organic carbon), surface mass concentration of aerosol components, and total extinction (and scattering ) aerosol optical thickness (AOT) at 550 nm. The total PM1.0, PM2.5, and PM10 may be derived with the formula described in the FAQs under the Documentation tab of this page. 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

m2tmnxaer_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2TMNXAER",
    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.