Satellites continuously peer down from orbit to take measurements of Earth, and this week a group of scientists set sail to verify some of those data points.
On June 2, the SCOAPE (Satellite Coastal
and Oceanic Atmospheric Pollution Experiment) research team, in partnership
with the U.S. Interior Department’s Bureau of Ocean Energy Management, took to
the seas in the Gulf of Mexico for its second campaign to make surface-based
measurements of air pollutants.
The NASA/GSFC SCOAPE team launches an ozonesonde weather balloon from the stern of the research vessel Point Sur during the May 2019 cruise. Ryan Stauffer (NASA/GSFC)
The primary pollutant scientists are measuring is nitrogen dioxide (NO2),
the compound that reacts with sunlight to make ground-level ozone, said Anne
Thompson, senior scientist emeritus for atmospheric chemistry at NASA’s Goddard
Space Flight Center in Greenbelt, Maryland, and senior researcher at the
University of Maryland, Baltimore County.
The Gulf of Mexico is highly
concentrated with oil and natural gas drilling platforms, which are sources of
NO2. By taking measurements of these emissions from the sea surface nearby,
scientists can help validate measurements taken from a much different vantage
point. The research vessel the scientists are using, Point Sur, is owned by the
University of Southern Mississippi and operated by the Louisiana Universities
Marine Consortium.
The Petronius deepwater oil platform flaring during the May 2019 SCOAPE cruise. The helicopter in the foreground is used as a means of transporting personnel to and from the platform. Ryan Stauffer (NASA/GSFC)
“We’re the eyes on the surface to understand how well the eyes in the sky
are working,” said Ryan Stauffer, research scientist for the atmospheric
chemistry and dynamics laboratory at Goddard. Stauffer is also the principal
investigator for the SCOAPE II project.
For the first iteration of the
project in 2019, ship-based measurements were compared to data gathered by the
Ozone Monitoring Instrument aboard NASA’s Aura satellite and the Tropospheric
Monitoring Instrument aboard ESA’s (European Space Agency) Sentinel-5 Precursor
satellite. Both instruments fly on polar orbiting satellites, which pass over
every part of the globe once per day. They capture snapshots at the same time
each day, but cannot capture the short-lived NO2 emissions that come and go at
different times.
In 2024, the research team is
working to validate the measurements taken by TEMPO (the Tropospheric Emissions: Monitoring of Pollution instrument),
which was launched on a commercial satellite in April 2023. The TEMPO
instrument provides a different perspective to the NO2 measurements due to its
geostationary orbit — it focuses solely on North America and has a constant
view of the Gulf of Mexico region. This allows scientists to better quantify
emissions and make comparisons across all daylight hours.
From space, satellites collect
measurements of the “total column” of air, which means they measure the
concentrations of NO2 from the land or ocean surface all the way up to the top
of the atmosphere. With SCOAPE, scientists are taking measurements from the
ship, about 33 feet above sea level, to focus measurements on the air that
people breathe.
The SCOAPE Pandora spectrometer instrument, which were used to gather the air quality near the operation sites, during sunset with a shallow water gas platform on the horizon. Ryan Stauffer (NASA/GSFC)
Learning more about how those surface measurements compare to what
satellites see in the total column can help scientists figure out how to use
satellite data most effectively. Measuring NO2 from space over the past two
decades has helped scientists understand how the compound affects air quality,
and has helped to inform policies to reduce emissions of the pollutant.
During SCOAPE’s 2019 campaign,
researchers detected concentrations of methane – a significant greenhouse gas – near the Gulf Coast. This time around, the
scientists are looking to accurately measure these concentrations from
the surface as well. They will mount the NASA Airborne Visible and InfraRed
Imaging Spectrometer–3 imaging spectrometer instrument on a Dynamic Aviation
B-200 plane to collect methane measurements above the Gulf, which will add an
extra layer to understanding emissions of this potent greenhouse gas from Gulf
of Mexico oil and gas operations.
It has historically been difficult
to measure methane from space, but scientists are working to build those
capabilities. As with NO2, taking surface measurements helps scientists better
understand the measurements taken from space.
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Source: NASA Scientists Take to the Seas to Study Air Quality - NASA
No comments:
Post a Comment