WNA-FLEXPART-BackTraj-2021: Backward Air Trajectory Simulations for Ozone Source Analysis

FLEXPART Lagrangian particle dispersion model simulations provide 15-day backward trajectories from receptor points over Western North America, matching ozone observations from 1994 to 2021. These hourly, global simulations at 1° x 1° resolution from the surface to 20 km altitude establish source-receptor relationships for tropospheric ozone. The dataset enables analysis of source contributions across diurnal, seasonal, and decadal timescales and can support studies of other co-located atmospheric components.

Use Cases

• Identifying geographic source regions contributing to high ozone events at specific receptor locations based on backward trajectory calculations.
• Analyzing seasonal or decadal trends in atmospheric transport patterns affecting Western North American air quality.
• Estimating source contributions from different atmospheric layers (surface to 20 km) to downwind ozone observations.
• Supporting source apportionment studies for other atmospheric trace gases or aerosols if co-located with the ozone receptor grid.

Strengths

• Covers a long observational period, with receptor data matching ozone measurements from 1994 to 2021.
• Provides high-resolution global simulations with hourly temporal and 1° x 1° spatial granularity.
• Includes vertical coverage from the surface up to 20 km above ground level, capturing tropospheric processes.

Limitations

• Key metadata is missing or conflicting: one source lists a 'last updated' date in 2026, while another states data collection was complete in 2021.
• The specific column schema and data volume (row count, file size) are not documented on any platform.
• The license is ambiguously listed as 'other-license-specified' without details on reuse terms.

Provenance

Source

National Aeronautics and Space Administration (NASA), generated with support from NASA’s Atmospheric Composition Campaign Data Analysis and Modeling program and the NASA High-End Computing Program.

Collection Method

Simulations using the FLEXible PARTicle (FLEXPART) Lagrangian particle dispersion model, driven by ERA5 reanalysis meteorological data.

Time Range

1994-2021 (period of matched ozone observations)

Freshness

2026-04-09 20:35:41.467270 (from datagov, but conflicts with 2021 completion date on nasa_earthdata)

Geography

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