Yearly nitrogen-dioxide air pollution over the US (TROPOMI)
What it measures. Yearly average levels of nitrogen dioxide (NO2), a harmful air pollutant, in the air column over the Continental United States, mapped on a fine grid of about 1 square kilometer. NO2 mostly comes from burning fossil fuels and is a marker for traffic and industrial pollution.
How it's made. Built by a George Washington University lab from daily NO2 readings taken by the TROPOMI instrument on Europe's Sentinel-5P satellite, then averaged into a yearly gridded map.
How & where you'd use it. Lets people track how air pollution is changing over time across U.S. cities and regions, supporting public-health and air-quality work since NO2 is tied to respiratory harm and the formation of ozone and fine particles.
What's measured
Coverage & cadence
- Time span2019-01-01 → ongoing
- Measured bySentinel-5P (TROPOMI)
- Processing levelLevel 3
- Spatial extent-124.75, 24.5, -66.76, 49.49
- 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 product provides level 3 annual averages of tropospheric Nitrogen dioxide (NO2) vertical column density derived from the level 2 Tropospheric Monitoring Instrument (TROPOMI) across the Continental United States oversampled to a spatial resolution of 0.01˚ x 0.01˚ (~1 km2) using a consistent algorithm from the European Space Agency (ESA) version 2.4 that can be used for trend analysis of air pollution. The dataset record began in 2019 and continues to the present. This L3 product was developed by the George Washington University Air, Climate and Health Laboratory as part of the NASA Health Air Quality Applied Science Team (HAQAST) using Level 2 version 2.4 TROPOMI NO2 files from the ESA. The TROPOMI instrument on Sentinel-5 Precursor acquires tropospheric NO2 column contents from low Earth orbit (~824 km above ground level) once per day globally at approximately 13:30 local time. NO2 is an air pollutant that adversely affects the human respiratory system and leads to premature mortality. NO2 is also an important precursor for ozone and fine particulates, which also have severe health impacts. In urban areas, the majority of NO2 originates from anthropogenic NOx (=NO+NO2; most NOx is emitted as NO, which rapidly cycles to NO2) emissions during high-temperature fossil fuel combustion. Tropospheric NO2 vertical column contents are qualitatively representative of near-surface NO2 concentrations and NOx emissions in urban/polluted locations.
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="HAQ_TROPOMI_NO2_CONUS_A_L3",
version="2.4",
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. Official links
- README Document VIEW RELATED INFORMATION
- Access the data via HTTPS. GET DATA
- Use the Earthdata Search to find and retrieve data sets across multiple data centers. GET DATA
- Access the data via the OPeNDAP protocol. USE SERVICE API
- Documentation with step-by-step instructions on accessing and reading data at GES DISC VIEW RELATED INFORMATION