A new study published by the Keck Institute for Space Studies (KISS) , in collaboration with Caltech, Rutgers University, and NASA's Jet Propulsion Laboratory (JPL), which is managed by Caltech for NASA, presents a roadmap for simultaneously combining data on the abundance of greenhouses gases with data on winds to better pinpoint emission sources. The findings will help improve the monitoring and mitigation of these gases, such as carbon dioxide and methane, which drive climate change.
"We have very good data on the abundance of greenhouse gases from space- and ground-based sensors but determining from these data the sources of these gases-estimating both their locations and intensity-depends on understanding how they are dispersed by the winds," explains Paul Wennberg, Caltech's R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering and a co-leader of the report.
"We need to have, simultaneously, a better understanding of the wind speeds and direction to improve these estimates," he says. "For example, we may see a plume of methane, but what is its source? Is it a natural wetland or a nearby facility associated with oil production? Having better coincident knowledge of the winds allows us to accurately trace the measured plume back to its source."
The report, " Tracing Greenhouse Gases: A Blueprint for a Joint Meteorology and Atmospheric Composition Program ," emerged from a five-day workshop held October 7-11, 2024, titled "Forging Community Consensus for an Integrated GHG [greenhouse gas] and Winds Program." Hosted by KISS at Caltech, the workshop was led by Mary Whelan, an environmental scientist at Rutgers University; Nick Parazoo, a terrestrial ecologist at JPL; and Wennberg. The effort brought together experts in both wind and greenhouse gas observations from 20 institutions, reflecting broad community engagement across academia, federal laboratories, and research organizations.
Zoom In to Image This illustration shows how greenhouse gas emissions and movement are studied at three scales: local, small regional, and large regional. Local scales focus on individual sites, such as factories as well as "sinks" like carbon dioxide removal projects. Regional scales track multiple nearby sources and sinks, while large scales capture how gases mix across wide areas of the atmosphere. Credit: Keck Institute for Space Studies/Victor Leshy
Currently, modeling and data assimilation of wind and atmospheric chemistry data are conducted separately. Operational weather centers routinely assimilate wind data but do not connect this data with greenhouse gas transport. On the other hand, research centers assimilate greenhouse gas measurements into atmospheric chemistry models to learn about carbon and climate but do not include wind data.
"The complexity of understanding air movement and atmospheric composition has fostered two relatively separate research communities. We can be more effective by bringing them together in a thoughtful way," Whelan says.
The report suggests that better integration of data from space observatories and ground sensors, in combination with weather models, can offer a clearer picture of what is going on.
"If we were to assimilate wind observations and greenhouse gas observations together in the same system, we would likely achieve greater benefits-more accurate weather forecasts and more accurate greenhouse gas transport in the atmosphere-than if we assimilate them in independent systems," says report author Derek Posselt, a research scientist at JPL.
Wennberg compares the situation to burning toast: "You might be sitting in your living room and smell faint smoke. Where is the smoke coming from, and how bad is the fire? If you have a window open, and it's particularly breezy in your house, the smoke can be readily dispersed, so a pretty big fire in your toaster may be required to produce the faint smell. On the other hand, if the house is closed up and the smoke is contained, the same smell could arise by just keeping the bread in the toaster only a few extra seconds."
By proposing an integrated greenhouse gas and winds program, the report lays the groundwork for future mission concepts, shared community platforms, and policy-relevant tools that can support climate action worldwide.
"The integrated program targeting long-term greenhouse gas management needs at local to global scales would be timely as NASA begins the process for the next decadal survey," Parazoo says. The Earth Science Decadal Survey, facilitated by the National Academy of Sciences, occurs every 10 years to set priorities in the field for the next decade.
"Multiscale monitoring over multiple decades is key to effective management of emissions and removals," Parazoo says. "It is not sufficient to only observe and study greenhouse gases locally, because it becomes difficult to monitor impacts globally. Long-term monitoring is necessary to ensure continued success of mitigation strategies. We must think integrated, we must think multi-scale, and we must think long term."
Harriet Brettle (MS '19), the executive director of KISS, says, "Bringing together 29 participants from four countries representing 20 organizations, the study exemplifies the mission of the Keck Institute for Space Studies to foster interdisciplinary collaboration, advancing integrated, space-based approaches to greenhouse gas monitoring."
