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Full catalog/M2TUNXAER
M2TUNXAER·v5.12.4·dataset

Daily haze, dust and smoke from weather model

MERRA-2 tavgU_2d_aer_Nx: 2d,diurnal,Time-averaged,Single-Level,Assimilation,Aerosol Diagnostics 0.625 x 0.5 degree V5.12.4 (M2TUNXAER) at GES DISC
atmosphere NASA GES_DISC Level 4 active
In plain English

What it measures. Monthly, hour-by-hour averages of tiny particles floating in the air worldwide: black carbon, dust, sea salt, sulfate, and organic carbon. It tracks how much of each is overhead and near the ground, plus how much they dim and scatter sunlight.

How it's made. Produced by NASA's MERRA-2 reanalysis, which blends a weather-and-climate computer model (GEOS) with decades of satellite observations rather than reading off a single instrument.

How & where you'd use it. Helps researchers study haze, dust, and smoke and estimate fine-particle air pollution (PM1, PM2.5, PM10) for health and air-quality work, using a long, consistent record going back to 1980.

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

M2TUNXAER (or tavgU_2d_aer_Nx) is a time-averaged 2-dimensional monthly diurnal means 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. This data collection is the monthly mean of data fields for each hour and is time-stamped with the central time of an hour starting from 00:30 UTC, e.g.: 00:30, 01:30, … , 23:30 UTC. 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

m2tunxaer_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="M2TUNXAER",
    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.