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Full catalog/M2_TMAX_PM25
M2_TMAX_PM25·v1·dataset

Fine-particle air pollution by country, monthly average

MERRA-2 avgM_2d_pm25_admin0, 2d, Single-Level, Country-Level Surface PM2.5 Monthly Mean Products V1 (M2_TMAX_PM25) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Gives the monthly average level of fine particle pollution (PM2.5) near the ground, summarized for each country and territory. Versions are provided both as plain averages and weighted toward where people actually live.

How it's made. Calculated from NASA's MERRA-2 model, which blends satellite and other data, by adding up the modeled pollution components (like soot, dust, sea salt and sulfate).

How & where you'd use it. Handy for comparing air pollution exposure between countries over time and for public-health and policy work, without needing a dense ground sensor network.

What's measured

ATMOSPHERE › AIR QUALITYATMOSPHERE › AIR QUALITY › PARTICULATESATMOSPHERE › AEROSOLS › DUST/ASH/SMOKEATMOSPHERE › AEROSOLS › PARTICULATE MATTERHUMAN DIMENSIONS › PUBLIC HEALTH › ENVIRONMENTAL HEALTH FACTORS › PARTICULATE MATTER CONCENTRATIONS

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

M2_TMAX_PM25 is a value-added product derived from the MERRA-2 aerosol monthly product M2TMNXAER_5.12.4 (or tavgM_2d_aer_Nx). The surface concentration of fine particulate matter (PM2.5) is calculated as the sum of individual aerosol components (organic carbon, black carbon, sulfate, sea salt, and dust) (Buchard et al., 2017) and is recast from the native MERRA-2 model grid. This data collection includes separate files for country-level (and territories) PM2.5 concentrations with and without population weighting applied. 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

m2_tmax_pm25_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2_TMAX_PM25",
    version="1",
    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.