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Full catalog/OMHCHO
OMHCHO·v004·dataset

Formaldehyde in the air, a smog ingredient (Aura)

OMI/Aura Formaldehyde (HCHO) Total Column 1-orbit L2 Swath 13x24 km V004 (OMHCHO) at GES DISC
atmosphere NASA GES_DISC Level 2 active
In plain English

What it measures. The total amount of formaldehyde in a column of air from the ground to space, along with error estimates, quality flags, and location information. Formaldehyde is a marker of certain pollution and an ingredient in smog formation.

How it's made. Derived from light measurements by the Ozone Monitoring Instrument on NASA's Aura satellite, with one file covering the daylit part of each orbit.

How & where you'd use it. Used to map sources of air pollution and study the chemistry that produces smog and ozone near the ground.

What's measured

ATMOSPHERE › ATMOSPHERIC CHEMISTRY › CARBON AND HYDROCARBON COMPOUNDS › FORMALDEHYDE

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) Formaldehyde Product OMHCHO contains total vertical column HCHO, standard errors (rms and sigma), quality flags, geolocation and other ancillary information. The algorithm lead for this product is Gonzalo Gonzalez Abad from the Harvard-Smithsonian Center, Cambridge, MA. The OMHCHO files are stored in the version 4 netCDF format. Each file contains data from the day lit portion of an orbit (~53 minutes). There are approximately 14 orbits per day. The average file size for the OMHCHO data product is about 35 MB.

Get the data

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

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