WNA-FLEXPART-BackTraj-1995: Western North American Air Mass Trajectories

Hourly, 15-day backward air mass trajectories were simulated for 1995 using the FLEXPART Lagrangian particle dispersion model driven by ERA5 reanalysis data. This dataset provides source-receptor relationships at a 1° x 1° spatial resolution from the surface up to 20 km altitude, designed to match gridded ozone observations over Western North America. The model output supports analysis of source contributions to tropospheric ozone and other atmospheric components across diurnal to decadal timescales.

Use Cases

• Attributing ozone source regions based on simulated 15-day backward trajectories.
• Analyzing seasonal or decadal changes in air mass transport patterns over Western North America.
• Investigating vertical layer contributions to pollutant concentrations at receptor sites.
• Supporting source contribution analyses for other atmospheric components co-located with the ozone receptors.

Strengths

• Provides high-resolution simulations with hourly temporal and 1° x 1° spatial resolution.
• Covers a significant vertical domain from the surface to 20 km altitude.
• Generated with NASA program support and high-performance computing resources.

Limitations

• Metadata completeness is low; specific column names, row counts, and file sizes are not provided.
• Conflicting 'last updated' dates exist between sources (2026-04-09 on datagov vs. 1995-12-31 on nasa_earthdata).
• The license is ambiguously listed as 'other-license-specified' without explicit terms.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Simulations using the FLEXPART Lagrangian particle dispersion model driven by ERA5 reanalysis data.

Time Range

1995

Freshness

2026-04-09 (from datagov, though this may be a metadata update)

Geography

Global simulations with receptor locations focused on Western North America (WNA).