Air pollution severely damages human health and the environment, causing 2 million premature deaths yearly. This has been a serious problem in the West for decades, but is also a growing concern for developing countries as their economies grow. Now, scientists in Cuba are applying a bottom-up approach to reduce pollution's toxic effects, using the latest scientific model to understand how air pollution spreads from major construction sites and power plants. Using this information, better mitigation strategies can be developed.
A key tool is AERMOD, (AMS/EPA Regulatory MODel), a state-of-the-art predictive 'air quality' tool developed by the American Meteorological Society(AMS) and the US Environmental Protection Agency (EPA). It uses local observational data to forecast the spread of pollutants such as sulfur dioxide, over areas of 50km or less.
This three-in-one model combines: (1) steady-state plume dispersion, using an algorithm designed to forecast the spread of emissions from stationary sources such as industrial plants; (2) an atmospheric model to calculate weather parameters such as air turbulence and friction - even accounting for the amount of solar radiation reflected by a surface; and (3) simulations that show how pollution reacts when flowing over hills or other terrain.
A leading proponent for this tool is Leonor Turtos, leader of a group that uses AERMOD on a national level to assess how pollution affects air quality among people in rural and metropolitan areas. Much like filling in a jigsaw puzzle, AERMOD collects data, piece-by-piece, to form an overall picture; the result is an hourly- updated 'pollution map' built with local data. Some of this data includes contaminant location, temperature, elevation, wind direction, windspeed and cloud cover, using observations obtained from the US Geological Survey.
It may seem strange to outsiders, given the nearly 50-year trade embargo between the US and Cuba, but there is a long history of scientists from the two countries collaborating. It also makes geographic sense, as southernmost Florida is only 90 miles from the closest part of Cuba.
It's all in the model
At least five years of meteorological data is needed to make an accurate model, said Turtos. "Local data can sometimes be incomplete and not in the format required, particularly in developing countries." This means a less accurate model in Cuba's case, critical to understanding the behavior of a complex plume of pollution from multiple sources.
To efficiently process the huge data sets involved, Turtos runs AERMOD on the GISELA grid, allowing for intensive data processing in hours, instead of days. Using the grid to process and share the large amounts of input (local pollution) and output (simulation) data, saves computing power, time and human resources. "This directly translates into a better understanding of the risks involved . . . allowing more informed decisions to be made" said Henry Ricardo, the Turtos' team meteorologist.
AERMOD is only one step on the pollution monitoring ladder; next year Turtos plans to use it with two larger-scale earth science models. One is CALPUFF, a multi-layered system that simulates the dynamic effects of weather conditions on pollution, from tens to hundreds of kilometers. The other is the WRF model, which works on scales from meters to thousands of kilometers. By combining all these models scientists will be able to see across the entire spectrum from the smallest to the largest picture.
But as Cuba's air-monitoring infrastructure is not as developed as other countries, the implementation of AERMOD has had a slow start, hindering its integration with GISELA. Turtos elaborated, "There is insufficient sharing of data and results, which wastes resources and time." She calls for better support and coordination within Cuba for standards of pollution measurement and computer modeling.
The goal is an infrastructure much like the UK Air Quality Monitoring Network, which allows data to be transferred efficiently. Tougher regulations on pollution monitoring and improved air quality standards are imperative to enabling Cuba's 11 million inhabitants to breathe cleaner air.
-Leonor Turtos and Henry Ricardo, Center for Information Management and Energy Development (Cubaenergia).
