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Full catalog/ML2HNO3_NRT
ML2HNO3_NRT·v005·dataset

Nitric acid in the air, fast delivery (Aura, near real-time)

MLS/Aura Near-Real-Time L2 Nitric Acid (HNO3) Mixing Ratio V005 (ML2HNO3_NRT) at GES DISC
atmosphere NASA GES_DISC Level 2 active
In plain English

What it measures. Profiles of how much nitric acid is present through the layers of the atmosphere, delivered quickly - typically within three hours of observation.

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

How & where you'd use it. Useful for timely study of upper-atmosphere chemistry (nitric acid plays a role in ozone processes) in selected regions, as long as the data are screened per the user guide.

What's measured

ATMOSPHERE › ATMOSPHERIC CHEMISTRY › NITROGEN COMPOUNDS › ATMOSPHERIC NITRIC ACID

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

ML2HNO3_NRT is the EOS Aura Microwave Limb Sounder (MLS) Near-Real-Time (NRT) product for nitric acid (HNO3). This product contains HNO3 profiles derived from the 190 and 240 GHz regions. 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 100 to 1.47 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

ml2hno3_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ML2HNO3_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.