Earth Data School
About
Full catalog/ML2H2O_NRT
ML2H2O_NRT·v005·dataset

Water vapor high in the atmosphere, fast delivery (Aura, near real-time)

MLS/Aura Near-Real-Time L2 Water Vapor (H2O) Mixing Ratio V005 (ML2H2O_NRT) at GES DISC
atmosphere NASA GES_DISC Level 2 active
In plain English

What it measures. Profiles of how much water vapor is present high in the atmosphere, from the upper troposphere into the stratosphere and above, delivered quickly within about three hours.

How it's made. Retrieved from microwave measurements by the Aura satellite's Microwave Limb Sounder; this fast version uses a simplified model to hit near-real-time deadlines, so it's less accurate than the standard product.

How & where you'd use it. Useful for timely monitoring of upper-atmosphere conditions in selected regions, provided the data are screened as the user guide recommends.

What's measured

ATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROFILES › WATER VAPOR MIXING RATIO PROFILES

Coverage & cadence

  • Time span2021-09-21 → ongoing
  • Measured byAura (MLS)
  • Processing levelLevel 2
  • 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

ML2H2O_NRT is the EOS Aura Microwave Limb Sounder (MLS) Near-Real-Time (NRT) product for water vapor (H2O). This product contains H2O profiles derived from the 190 GHz region. The NRT data are typically available within 3 hours of observation and are broken into files containing about 15 minutes of data. The most recent 7 days of data are available online. Spatial coverage is near-global (-82 degrees to +82 degrees latitude), with each profile spaced 1.5 degrees or ~165 km along the orbit track (roughly 15 orbits per day). The vertical coverage is from 147 to 1 hPa. The MLS NRT algorithm uses a simplified fast forward model to meet Near Real Time data latency requirements and are therefore not as accurate as the retrievals that constitute the standard MLS products. Nevertheless the results are scientifically useful in selected regions of the Earth's atmosphere provided that the data are screened according to the recommendations in the MLS NRT User Guide and the MLS L2 Data Quality Document for Standard Products.

Get the data

ml2h2o_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ML2H2O_NRT",
    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.