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OMTO3G·v004·dataset

Total ozone overhead, gridded daily (Aura, 0.25 degree)

OMI/Aura Ozone (O3) Total Column Daily L2 Global Gridded 0.25 degree x 0.25 degree V004 (OMTO3G) at GES DISC
atmosphere NASA GES_DISC Level 2G active
In plain English

What it measures. Total ozone overhead binned into a daily 0.25-degree global grid, along with extras like cloud cover, cloud pressure, terrain height, and quality flags. Pixels are kept un-averaged so users can apply their own filtering.

How it's made. Built from the orbit-by-orbit OMI total ozone measurements on NASA's Aura satellite, sorted into fine grid boxes for each 24-hour period rather than averaged.

How & where you'd use it. Used by scientists who want daily gridded ozone but prefer to choose their own quality screening and averaging when making maps.

What's measured

ATMOSPHERE › ATMOSPHERIC CHEMISTRY › OXYGEN COMPOUNDS › ATMOSPHERIC OZONE › TOTAL COLUMN OZONEATMOSPHERE › ATMOSPHERIC RADIATION › REFLECTANCEATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESS › UV AEROSOL INDEX

Coverage & cadence

  • Time span2004-10-01 → ongoing
  • Measured byAura (OMI)
  • Processing levelLevel 2G
  • 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

This Level-2G daily global gridded product OMTO3G is based on the pixel level OMI Level-2 Total Ozone Product OMTO3. The OMTO3 product is from the enhanced TOMS version-8 algorithm that essentially uses the ultraviolet radiance data at 317.5 and 331.2 nm. The OMTO3G data product is a special Level-2 Global Gridded Product where pixel level data are binned into 0.25x0.25 degree global grids. It contains the data for all L2 scenes that have observation time for the 24-hour period beginning at 00:00:00 UTC. All data pixels that fall in a grid box are saved without averaging. Scientists can apply a data filtering scheme of their choice and create new gridded products. The OMTO3G data product contains almost all parameters that are contained in the OMTO3. For example, in addition to the total column ozone it also contains cloud fraction, cloud pressure, terrain height, geolocation, solar and satellite viewing angles, and quality flags. The OMTO3G files are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains daily data from approximately 15 orbits. The maximum file size for the OMTO3G data product is about 150 Mbytes.

Get the data

omto3g_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="OMTO3G",
    version="004",
    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.