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Updated: May 31, 2026

Image-based Lagrangian Particle Tracking in Bed-load Experiments
Published on: July 20, 2017
Regional source identification using Lagrangian stochastic particle dispersion and HYSPLIT backward-trajectory models
Darko Koracin1, Ramesh Vellore, Douglas H Lowenthal
1Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA. Darko.Koracin@DRI.edu
The Lagrangian Stochastic Particle Dispersion Model (LSPDM) significantly improved air pollution source identification compared to HYSPLIT, accurately pinpointing emission regions impacting receptors. This research highlights LSPDM
Area of Science:
- Atmospheric Science
- Environmental Modeling
- Air Quality Assessment
Background:
- Accurate source identification is crucial for effective air quality management and policy development.
- Traditional trajectory models like HYSPLIT have limitations in accurately simulating dispersion and identifying emission sources.
- Mesoscale meteorological models provide essential wind field data for dispersion modeling.
Purpose of the Study:
- To evaluate the effectiveness of the receptor-oriented inverse mode Lagrangian Stochastic Particle Dispersion Model (LSPDM) for source identification.
- To compare LSPDM's performance against the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model using MM5 and EDAS wind inputs.
- To assess the impact of different vertical levels on backward trajectory analysis for source apportionment.
Main Methods:
- Utilized the Lagrangian Stochastic Particle Dispersion Model (LSPDM) in inverse mode with 12-km Mesoscale Model 5 (MM5) wind fields.
- Compared LSPDM results with Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) using MM5 (12-km) and Eta Data Assimilation System (EDAS, 80-km) wind data.
- Analyzed four 7-day summertime events in 2002, calculating residence times and comparing them with Community Multiscale Air Quality (CMAQ) model-predicted sulfate concentrations.
Main Results:
- LSPDM successfully identified the first- and second-ranked emission regions in 37 out of 40 cases, significantly outperforming HYSPLIT (21-16 cases).
- LSPDM achieved a higher correlation coefficient (0.89) and a lower normalized root mean square error (0.17) compared to HYSPLIT (0.55-0.62 and 0.30-0.32, respectively).
- HYSPLIT underestimated near-receptor sources and overestimated distant ones due to a lack of stochastic dispersion treatment.
Conclusions:
- The receptor-oriented inverse mode LSPDM demonstrates superior capabilities for air pollution source identification compared to standard HYSPLIT backward-trajectory analysis.
- LSPDM's inclusion of stochastic dispersion provides more accurate residence time distributions and source apportionment.
- Averaging HYSPLIT results from multiple vertical levels improved its consistency but did not match LSPDM's overall performance.
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