TROPESS CrIS-SNPP: Atmospheric Gas Profiles Over Los Angeles Megacity

NASA's TROPESS project provides vertical profiles of seven key atmospheric gases and temperature over a 3x3 degree region centered on Los Angeles. Data from the Suomi-NPP satellite's CrIS instrument are processed daily from 2016 to 2021 using the MUSES optimal estimation algorithm. Each netCDF file offers measurements at 17 vertical levels with a 14 km spatial resolution, accompanied by formal uncertainties.

Use Cases

• Tracking urban methane (CH4) and carbon monoxide (CO) emissions and their vertical dispersion.
• Analyzing the vertical distribution of ozone (O3) and its precursors like peroxyacetyl nitrate (PAN).
• Studying atmospheric water vapor (H2O) and its isotopologue HDO for hydrological cycle insights.
• Investigating ammonia (NH3) pollution from agricultural and urban sources over the Los Angeles basin.
• Validating chemical transport models with satellite-derived vertical profile data.

Strengths

• Provides a focused 5.3-year time series (2016-01-02 to 2021-05 21) for a specific megacity region.
• Offers vertically resolved data at 17 levels from the surface to 0.1 hPa, a detail not common in all satellite products.
• Includes formal uncertainties for each retrieved gas and temperature, supporting rigorous error analysis.
• Data is part of a NASA-standard processed collection (TROPESS) with a documented algorithm (MUSES).

Limitations

• Spatial coverage is limited to a 3x3 degree region over Los Angeles, not global or continental.
• Key metadata like row count, file size, and specific column names are unavailable across all platforms.
• The dataset's update status is unclear; the last metadata update is listed as 2026, but the data time range ends in 2021.

Provenance

Source

NASA TROPESS project, GES DISC, Principal Investigator Kevin W. Bowman.

Collection Method

Satellite remote sensing via the CrIS instrument on the Suomi-NPP platform, processed with the MUSES optimal estimation algorithm.

Time Range

2016-01-02 to 2021-05-21

Freshness

2026-04-09 21:35:52.370157

Geography

3x3 degree region centered on the Los Angeles megacity.