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U.S. and European scientists take measures to improve air pollution and climate change predictions

Posted: January 26, 2011

AQ-ALOFT Graphic

EPA merges models and measurements to understand relationships among environment, human health and air quality

Sometimes pollution and greenhouse gases emitted into the Earth’s atmosphere can remain close to the ground, where they have the potential to cause human health problems. Other times, these pollutants can move upwards into the atmosphere where they can be mixed and transported across states, regions, countries, and continents.

Air quality professionals, scientists, and policy makers at the U.S. Environmental Protection Agency (EPA) rely on the accuracy of computer-model-generated predictions of air pollution, weather, and climate change to protect public health and improve air quality. However, these same predictions are critically dependant on the accuracy of computer models’ representations of chemical processes that occur in the atmosphere.

Could the accuracy of these models be improved by incorporating real-world measurements of atmospheric pollutants into them? U.S. and European scientists believe they would—and that, in fact, they do. In 1993, European scientists began collaborations with intercontinental airlines to collect measurements in the atmosphere using onboard instruments. The work has been carried out via a project called Measurements of OZone, water vapor, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft, or MOZAIC. European scientists developing this project have been making MOZAIC data available to users at their request. However, in 2010 researchers, meteorologists, and modelers at EPA initiated an endeavor that, if successful, will lend EPA support to create the first such program in the United States. The data from this program would be linked with the European MOZAIC program, and together, the datasets could provide greater scientific understanding of regional and intercontinental air pollution transport.

Jim Szykman, EPA principal investigator, is laying its foundation through an initiative called Air Quality–Above the Lowest part of the Troposphere, or AQ–ALOFT.

AQ–ALOFT will connect measurements of atmospheric pollution collected by MOZAIC’s European-based flights and U.S.-based ground-level sensors, with computer model predictions to demonstrate the impact of the MOZAIC measurements to the atmospheric modeling community. The goal is to paint a more accurate picture of how society is impacted by the relationships among the environment, human activities, air quality, and climate change.

Szykman and EPA colleague Brian Eder expect that results of AQ-ALOFT will improve decision support models, including the Community Multiscale Air Quality (CMAQ) model, and users’ ability to generate more realistic and accurate predictions about the impact of chemicals mixing and moving in different layers of the atmosphere.

First, to bring AQ-ALOFT to fruition Szykman and the team will combine the European-based data, which contains information from thousands of flights, with other upper air chemistry, weather measurements, and air quality data collected at the Earth’s surface in many U.S. locations. The data will be made available for routine use within EPA through the Remote Sensing Information Gateway.

The gateway is a user friendly, enhanced data infrastructure that can house and support the collection and analyses of massive amounts of measurement and model data sets. It provides users the ability to tap into environmental measurement and modeling data, integrate the data across various time and space scales, and display it through visualization and animations; completing complex data processing tasks in minutes rather than in months, as in the past.

Second, EPA modelers and others who are participating in the Air Quality Modeling Evaluation International Initiative (AQMEII) will use the measurement data to assess the accuracy of predictions of regional and global atmospheric transport of chemicals. Researchers will use the measurements to develop and test new methods to identify the most critical chemical and physical measurements for improving air quality. This will be accomplished, in part, through structured and thorough evaluations of 22 existing air quality models in 13 countries around the world.

Third, the AQ-ALOFT initiative pre-establishes the value of the data to air quality professionals in the United States as well as decision and policy makers at EPA. As such, AQ-ALOFT becomes a precursor to a new U.S. program led by Owen Cooper, research scientist at the University of Colorado and the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory. Cooper and his collaborators from Europe, NOAA, NASA, U.S. Department of Energy, EPA and several universities see that a MOZAIC-like effort in the United States would prove beneficial for air quality and climate monitoring research.

Cooper’s effort is called IAGOS (In-service Aircraft for the Global Observing System) in the USA. His goal is to bring the next generation of MOZAIC, the new European IAGOS program, to the United States. The aim is install IAGOS air pollution monitoring equipment on U.S.-based commercial aircraft to help the IAGOS program realize its goal of 20 globally-based aircraft. With each instrumented aircraft transmitting upwards of 6,300 near real-time atmospheric measurements per flight, worldwide monitoring of pollutants above the Earth's surface is possible.

These approaches and the measurements they provide are expected to facilitate and stimulate decisions made around the world that will better protect the air people breathe and enhance understanding of the impacts of climate change in local, regional, national, and international communities.

AQ-ALOFT is an EPA-funded initiative which began in 2010 and concludes in 2012. It is part of the agency’s commitment to developing and sustaining a Global Earth Observation System of Systems.

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