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Full catalog/OMTO3
OMTO3·v004·dataset

Total ozone overhead (Aura, per orbit)

OMI/Aura Ozone(O3) Total Column 1-Orbit L2 Swath 13x24 km V004 (OMTO3) at GES DISC
atmosphere NASA GES_DISC Level 2 active
In plain English

What it measures. The total amount of ozone in a column of air from the ground all the way up to space, measured strip by strip along each orbit at roughly 13x24 km resolution. It also includes extras like cloud cover and surface reflectivity.

How it's made. Derived from ultraviolet light readings by the Ozone Monitoring Instrument on NASA's Aura satellite, processed with the TOMS version-8 algorithm to turn raw radiances into ozone amounts.

How & where you'd use it. Used to monitor the ozone layer and track the ozone hole, and to study how clouds, haze, and trace gases affect the atmosphere.

What's measured

ATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESS › UV AEROSOL INDEXATMOSPHERE › ATMOSPHERIC CHEMISTRY › OXYGEN COMPOUNDS › ATMOSPHERIC OZONE › COLUMN AMOUNT OZONEATMOSPHERE › ATMOSPHERIC RADIATION › REFLECTANCE

Coverage & cadence

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

The Aura Ozone Monitoring Instrument (OMI) Level-2 Total Column Ozone Data Product OMTO3 (Collection Version 004) is available from the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) for the public access. This level-2 global total column ozone product (OMTO3) is based on the enhanced TOMS version-8 algorithm that essentially uses the ultraviolet radiance data at 317.5 and 331.2 nm at a pixel resolution of 13 x 24 km at nadir. OMI hyper-spectral measurements help in the corrections for the factors that induce uncertainty in ozone retrievals (e.g., cloud and aerosol, sea-glint effects, profile shape sensitivity, SO2 and other trace gas contamination). In addition to the total ozone values this product also contains some auxiliary derived and ancillary input parameters including N-values, effective Lambertian scene-reflectivity, cloud fraction, cloud pressure, ozone below clouds, terrain height, geolocation, solar and satellite viewing angles, and quality flags. The shortname for this Level-2 OMI total column ozone product is OMTO3. The algorithm for this product was originally developed by a team led by Dr. Pawan K. Bhartia at NASA Goddard Space Flight Center. The current product lead is Dr. Can Li. The OMTO3 files are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the day lit portion of an orbit (~53 minutes). There are approximately 14 orbits per day. The maximum file size for the OMTO3 data product is approximately 35 MB.

Get the data

omto3_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="OMTO3",
    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.