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Full catalog/ML3MBCH3CL
ML3MBCH3CL·v005·dataset

Methyl chloride gas levels in the air, monthly (Aura)

MLS/Aura Level 3 Monthly Binned Methyl Chloride (CH3Cl) Mixing Ratio on Assorted Grids V005 (ML3MBCH3CL) at GES DISC
atmosphere NASA GES_DISC Level 3 active
In plain English

What it measures. Monthly amounts of methyl chloride, a chlorine-containing gas, high up in the atmosphere, reported at different altitudes and latitudes. Methyl chloride is a natural source of ozone-depleting chlorine.

How it's made. Built from microwave signals picked up by the Microwave Limb Sounder on NASA's Aura satellite, then averaged into monthly bins on several grids; data run from 2005 onward.

How & where you'd use it. Helps scientists track the chlorine budget of the stratosphere and understand processes affecting the ozone layer.

What's measured

ATMOSPHERE › ATMOSPHERIC CHEMISTRY › HALOCARBONS AND HALOGENS › METHYL CHLORIDE

Coverage & cadence

  • Time span2004-08-02 → ongoing
  • Measured byAura (MLS)
  • Processing levelLevel 3
  • Spatial extent-180, -82, 180, 82
  • 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

ML3MBCH3CL is the EOS Aura Microwave Limb Sounder (MLS) monthly binned on various vertical grids product for methyl chloride (CH3Cl) derived from radiances measured by the 640 GHz radiometer. The data version is 5.1. Data coverage is from August 2005 to current. Spatial coverage is near-global (-82 to +82 degrees latitude) at a spatial resolution of 4 degrees latitude by 5 degrees longitude. The recommended useful vertical range is between 147 and 4.64 hPa, and the vertical resolution ranges between 4-6 km in the lower stratosphere and 8-10 km above 14 hPa. Users of the ML3MBCH3CL data product should read chapter 4 and section 3.3 of the EOS MLS Level 2 Version 5 Quality Document for more information. The data files are archived in the netCDF4 format, which is also compatible with HDF5 readers and tools. Each file contains six group objects: lat-lon map vs pressure, lat vs pressure zonal mean, lat-lon map vs "potential temperature", lat vs "potential temperature" zonal mean, "equivalent latitude" vs "potential temperature" zonal mean, and vortex average vs "potential temperature". Each group has a set of data (average, min, max, std dev, rms) and geolocation fields, grid attributes, and metadata.

Get the data

ml3mbch3cl_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ML3MBCH3CL",
    version="005",
    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.