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Full catalog/OMHCHOG
OMHCHOG·v003·dataset

Formaldehyde in the air, gridded daily (Aura, 0.25 degree)

OMI/Aura Formaldehyde (HCHO) Total Column Daily L2 Global Gridded 0.25 degree x 0.25 degree V3 (OMHCHOG) at GES DISC
atmosphere NASA GES_DISC Level 2G active
In plain English

What it measures. Daily amounts of formaldehyde in the air worldwide, reported as the total amount in a column of atmosphere overhead, along with error estimates, quality flags, and location details.

How it's made. Built from the OMI instrument on NASA's Aura satellite by sorting individual pixel-level formaldehyde measurements into a fine 0.25-degree grid (without averaging them together).

How & where you'd use it. Formaldehyde is a marker of certain pollution and natural plant emissions, so this helps study air quality and the chemistry behind smog; users can filter and combine it to make their own cleaner maps.

What's measured

ATMOSPHERE › ATMOSPHERIC CHEMISTRY › CARBON AND HYDROCARBON COMPOUNDS › FORMALDEHYDE

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 OMHCHOG is based on the pixel level OMI Level-2 HCHO product OMHCHO. OMHCHOG data product is a special Level-2 Global Gridded Product where pixel level data are binned into 0.25x0.25 degree grids. It contains data for all L2 scenes that have observation time between UTC times of 00:00:00 and 23:59:59.9999. All data pixels that fall in a grid box are saved without Averaging (third dimension provides indexing for the data points in each small grid). Scientists can apply a data filtering scheme of their choice and create Level-3 global gridded products. The OMHCHOG data product contains almost all parameters (e.g. total vertical column HCHO, standard errors, quality flags, geolocation and ancillary information) that are contained in the OMHCHO product. The OMHCHOG data are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the day lit portions of 14 to 15 orbits that cover the globe in a day. The average file size for the OMGCHOG data product is about 55 Mbytes.

Get the data

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

results = earthaccess.search_data(
    short_name="OMHCHOG",
    version="003",
    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.