Dr. Gonzalo González Abad, Center for Astrophysics, Smithsonian Astrophysical Observatory
Research Interests: Space-based measurements of atmospheric trace gases and the application of these measurements to the study of air quality.
Research Highlights: When people speak of trace gases associated with climate change, greenhouse gases like carbon dioxide, methane, and nitrous oxide get most of the attention. However, there are a host of other atmospheric trace gases that, even though they don’t occur in large quantities, are important to life on Earth and play critical roles in atmospheric processes.
Two examples of such trace gases are formaldehyde and glyoxal, both of which can react with nitrogen oxides to increase levels of ozone, another greenhouse gas that impacts climate, air quality, and the biosphere. Formaldehyde and glyoxal can also react with other atmospheric chemicals to create secondary aerosols, which may promote cloud formation and boost Earth’s albedo (the planet’s capacity to reflect solar radiation back into space), leading to regional cooling. Therefore, gathering specific information on the concentrations and sources of these trace gases and how they behave in the atmosphere is essential for monitoring air quality, responding to the effects of climate change, and evaluating the policies and regulations governing air quality and the release of atmospheric pollutants.
Among the atmospheric scientists engaged in such work is Dr. Gonzalo González Abad, an atmospheric physicist at the Center for Astrophysics, a collaboration between the Smithsonian Astrophysical Observatory and Harvard College Observatory in Cambridge, Massachusetts.
“The goal of my work is to produce retrievals of trace gas species relevant to air quality,” González Abad said. “In particular, I am working to develop consistent, long-term observations of formaldehyde, water vapor, glyoxal, bromine monoxide, and ozone from 1996 to the present.”
González Abad is especially interested in formaldehyde and glyoxal, which play important roles in atmospheric chemistry, including the production or destruction of ozone in the troposphere.
“These species do not have large concentrations in the stratosphere. They are mostly in the troposphere and the boundary region between [the troposphere and the stratosphere],” he said. “They regulate the amount of oxidative power of the atmosphere in conjunction with nitrogen dioxide, so they play an important role in ozone production and destruction and in atmospheric pollution. They also play a role in the production of secondary aerosols, or aerosols that form through coagulation of water and other particles. This is how these types of aerosols grow.”
Formaldehyde is often a byproduct of the oxidation of another trace gas: isoprene, a biogenic chemical produced during photosynthesis and emitted mainly from the leaves of woody plants. Isoprene is a volatile compound known to react with hydroxyl radicals, a type of molecule that reduces the oxidative capacity of the atmosphere and increases the survival of compounds like methane, which contributes to global warming and is the primary contributor to the formation of ground-level ozone. By monitoring atmospheric concentrations of formaldehyde, scientists can zero-in on sources of isoprene emissions and track its concentration in the atmosphere.
“NASA doesn’t have a long-term record of formaldehyde retrievals from multiple satellites. The European Space Agency [ESA] has a long-term record for formaldehyde using [data from] four satellites, but it doesn’t include data from the Ozone Profiler and Mapping Suite (OMPS) instrument,” González Abad said. “OMPS is now the workhorse for NASA and NOAA, so the reason we are developing this [formaldehyde data product] is because we can and because we want to use all the sensors that are available from NASA and NOAA, and also ESA.”
