An integrated WRF/HYSPLIT modeling approach for the assessment of PM2.5 source regions over the Mississippi Gulf Coast region

Abstract

Fine particulate matter (PM2.5) is majorly formed by precursor gases, such as sulfur dioxide (SO2) and nitrogen oxides (NOx), which are emitted largely from intense industrial operations and transportation activities. PM2.5 has been shown to affect respiratory health in humans. Evaluation of source regions and assessment of emission source contributions in the Gulf Coast region of the USA will be useful for the development of PM2.5 regulatory and mitigation strategies. In the present study, the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model driven by the Weather Research & Forecasting (WRF) model is used to identify the emission source locations and transportation trends. Meteorological observations as well as PM2.5 sulfate and nitric acid concentrations were collected at two sites during the Mississippi Coastal Atmospheric Dispersion Study, a summer 2009 field experiment along the Mississippi Gulf Coast. Meteorological fields during the campaign were simulated using WRF with three nested domains of 36, 12, and 4 km horizontal resolutions and 43 vertical levels and validated with North American Mesoscale Analysis. The HYSPLIT model was integrated with meteorological fields derived from the WRF model to identify the source locations using backward trajectory analysis. The backward trajectories for a 24-h period were plotted at 1-h intervals starting from two observation locations to identify probable sources. The back trajectories distinctly indicated the sources to be in the direction between south and west, thus to have origin from local Mississippi, neighboring Louisiana state, and Gulf of Mexico. Out of the eight power plants located within the radius of 300 km of the two monitoring sites examined as sources, only Watson, Cajun, and Morrow power plants fall in the path of the derived back trajectories. Forward dispersions patterns computed using HYSPLIT were plotted from each of these source locations using the hourly mean emission concentrations as computed from past annual emission strength data to assess extent of their contribution. An assessment of the relative contributions from the eight sources reveal that only Cajun and Morrow power plants contribute to the observations at the Wiggins Airport to a certain extent while none of the eight power plants contribute to the observations at Harrison Central High School. As these observations represent a moderate event with daily average values of 5–8 μg m−3 for sulfate and 1–3 μg m−3 for HNO3 with differences between the two spatially varied sites, the local sources may also be significant contributors for the observed values of PM2.5.

Atmospheric Trace Gas (NO2 and O3) Variability in South Korean Coastal Waters, and Implications for Remote Sensing of Coastal Ocean Color Dynamics

“…The NOAA Air Resources Laboratory's (ARL's) HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT4) modeling system [33,34] was used to compute air parcel trajectories and determine the origin of air masses sampled by the shipboard PSI-24 on RV Onnuri during KORUS OC. HYSPLIT has been used extensively in the literature in a variety of applications to simulate the atmospheric transport, dispersion, and deposition of pollutants and hazardous materials [35][36][37][38]. HYSPLIT simulations were run using meteorological data from the Global Data Assimilation System (GDAS1.0), because the complex terrain of the Korean Peninsula necessitated favoring a data-set which allowed for the most representative modeling of vertical motion [39].…”

Modelling Missing Data for PM2.5 Time Series Forecasting with Computational Intelligence

“…The selection of these PM 2.5 related parameters is based on the results of several research work recently reported in the literature (see e.g. [14], [15]).…”

Asthma Trends in Mississippi Coastal Region with Air Pollutants and Meteorological Factors

“…The air quality in these regions is also indirectly affected by the increasing transportation and construction associated with the rapid industrial growth over the US Gulf of Mexico. The weather patterns also play a prominent role in the dispersion of primary and secondary pollutants over the atmosphere to distant places from the sources [2,3].…”