The GES DISC has created the Giovanni Air Quality Instance for visualization and exploration of remotely- sensed and in situ data products related to air quality. For the continental United States, the Air Quality instance features Environmental Protection Agency AIRNow PM2.5 data from ground-based monitoring stations. PM2.5 is also known as Fine Particulate Matter, and it indicates the concentration of aerosol particles less than 2.5 μm in diameter. PM2.5 is a pollutant because particles of this size can lodge deep in human lungs and cause health problems, such as asthma, emphysema, respiratory difficulty, and chronic bronchitis. The PM2.5 product is provided by the cross-agency AIRNow program.
An image of the PM2.5 data product for the New England region on August 25, 2007. Elevated concentrations are visible over southern New York State, western Massachusetts, and southern Vermont.
Click image for larger version.
In addition to the PM2.5 data product, the Air Quality Instance also includes aerosol and cloud data products from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua satellites, and aerosol products from the Ozone Monitoring Instrument (OMI) on the Aura satellite. Unlike the PM2.5 data product, all of the remotely-sensed data products are available globally.
The Giovanni system provides several different rapid visualization and analysis capabilities that can be utilized to examine the data in the Air Quality instance. Users can generate maps of specific data products, time-series, and Hovmöller plots. Multiple data products can be plotted in the same time-series. Users can also create maps of the correlations between different data products, which indicate if these data products are related to each other over a specific time interval.
Correlation map: PM2.5 and MODIS Aerosol Optical Depth during July 2007, showing high correlations between these two data products. Many of the high-correlation areas in this image could be related to smoke from summer wildfires.
Shown below are other types of events that influence air quality. The "Haze" custom color palette was used to show how Giovanni has considerable flexibility in its visualization menu, providing an easy way to prepare graphics for presentations and research papers. Click on each image to view it full-size.
|Vog ("volcanic smog") || |
|MODIS true-color image of volcanic haze over the Hawaiian Islands, April 26, 2008 || |
Giovanni visualization of MODIS Aerosol Optical Depth data on April 26, 2008.,
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|Southern California Wildfires, October 2003 || |
|MODIS image of Southern California wildfires on October 26, 2003. || |
Giovanni visualization of PM2.5 data product for California in October 2003.
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|Saharan Dust Storm over the Atlantic || |
|MODIS image of a dust storm over the Atlantic Ocean, March 4, 2004 || |
Giovanni visualization of MODIS Aerosol Optical Depth data for this dust storm.
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Go to the Giovanni Air Quality Instance