Research Highlight:
HYSPLIT model forecasts pollutant levels in coastal Spain

A high resolution modeling system to forecast hourly pollutant concentrations for the coastal city of Huelva in southwest Spain and the Canary Islands started routine experimental testing recently. This work is a part of the ongoing collaboration between NOAA’s Air Resources Laboratory, the Universidad de Huelva, and the Instituto Nacional de Meteorologia (National Institute of Meteorology) at the Canary Islands in Spain. The system, run at the National Institute of Meteorology, uses NOAA’s HYSPLIT model to calculate the emission, transport, dispersion and deposition of Arsenic and Sulfur Dioxide as emitted from several large nearby point sources. The HYSPLIT simulation is driven by outputs from the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5), with a horizontal resolution of 2 km. The model outputs will be compared against field measurements of meteorological variables and pollutant concentrations to assess the system’s performance.

Although the HYSPLIT model is currently used to forecast the dispersion of a potential hazardous material released over urban scales in the U.S., it has not been possible to evaluate the model against concentrations measured in the field. This is because most U.S. cities have too many interfering sources to properly evaluate the modeling system and limited resources have been available for collecting data sets for model evaluation. In Huelva and the Canary Islands, there are well characterized sources of Arsenic and Sulfur Dioxide emissions that offer a unique opportunity to evaluate the model performance against measured values in a setting similar to that of an accidental hazard materials release.

Forecasting the behavior of hazardous materials released into the atmosphere is fundamental in order to minimize human exposure to harmful levels. In particular, an accurate estimation of the hourly variability in the concentrations is essential for emergency applications. While high resolution dispersion studies carried out using HYSPLIT have demonstrated the potential use of this simulation tool, the studies only have been performed for limited periods of time or have used longer time-averaged measurements for verification. This is the first application of the HYSPLIT model to forecast Arsenic and Sulfur Dioxide levels at high resolution.