WNA-FLEXPART-BackTraj-1999: 1999 Western North America Air Mass Back Trajectories

WNA-FLEXPART-BackTraj-1999 contains backward trajectory simulations for 1999, modeling the transport of air masses to receptor sites over Western North America. The dataset uses the FLEXPART Lagrangian particle dispersion model driven by ERA5 reanalysis to provide 15-day, hourly, global source-receptor relationships at a 1° x 1° spatial resolution from the surface to 20 km altitude. It is designed to analyze source contributions to tropospheric ozone observations from instruments like ozonesondes and aircraft, supporting studies across diurnal to decadal timescales.

Use Cases

• Attributing ozone source regions based on simulated backward air mass trajectories.
• Analyzing seasonal or decadal changes in atmospheric transport patterns to specific observation sites.
• Investigating vertical layer contributions to surface or column ozone observations.
• Supporting source contribution analyses for other atmospheric components co-located with the ozone receptors.

Strengths

• Provides high-resolution global simulations with hourly temporal and 1° x 1° spatial detail.
• Covers a vertical range from the surface to 20 km above ground level.
• Generated with NASA HEC program support, indicating high-performance computing provenance.

Limitations

• Metadata completeness is low: column names, row counts, and exact file sizes are unknown across all platforms.
• Conflicting 'last updated' dates exist between sources (1999-12-31 vs. 2026-04-09), creating uncertainty about provenance timing.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

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

Time Range

1999

Freshness

2026-04 09 20:36:20.352871

Geography

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