NASA and the Environmental Protection Agency (EPA) completed a short but
intense field campaign to study air quality in the San Joaquin Valley in
central California in mid-March 2007.
Using instruments on aircraft, satellites, and at ground sites, scientists
are working to improve observations and understanding of air quality in this
region, an area that is plagued with air pollution. Jim Szykman, an EPA
research scientist working at NASA Langley Research Center in Hampton, VA
and Rebecca Rosen, also from the EPA, are the co-principal investigators for
the San Joaquin Valley Advanced Monitoring Initiative. Together the EPA and
NASA are using a suite of instruments to study atmospheric particles, called
aerosols, which come from many sources: burning wood; vehicles; construction
and agricultural activities; and stationary sources such as refineries.
During the campaign, researchers flew HSRL on NASA 529, a King Air B200
aircraft, based at NASA Langley.
Right now, researchers use aerosol measurements from the Moderate Resolution
Imaging Spectroradiometer (MODIS), an instrument on the NASA Terra and Aqua
satellites. But, the terrain in the San Joaquin Valley makes it more
difficult for MODIS to make accurate measurements of aerosols in this region.
Another challenge with MODIS is that researchers cannot see where the
particles are located vertically. They can only obtain measurements for the
total column of the atmosphere, from the ground all the way to the upper
atmosphere. Together, the lidar and MODIS instruments can determine whether
this column has a high concentration of pollution and whether that pollution
is further up in the sky or at the ground level, where the majority of the
population lives and breathes.
Through this field campaign and other efforts during the
"Advanced Monitoring Initiative," the EPA is improving its understanding
of how environmental factors affect human health and ecological well being.
Projects from this initiative will enable a better understanding of how to
improve data to support and enhance environmental policy, management, and decision making.
Also, for more information about the San Joaquin Valley campaign, visit:
Funding for the deployment of the NASA King Air was provided by NASA and the Department of Energy (DOE) Atmospheric Science Program.
Logistical support was provided by NOAA ESRL. The information contained herein is provided as a public service, with the understanding
that NASA, DOE, NOAA, and the SJV project collaborators make no warranties, either expressed or implied, concerning the
accuracy, completeness, reliability, or suitability of the information. Do not quote or cite without permission. Permission for use of
these data and additional information may be obtained from the investigating scientists: Chris Hostetler, Richard Ferrare, or John Hair.
The data are preliminary and subject to change.