Colm Sweeney

Aircraft Program PI

Mailing address:
Colm Sweeney
325 Broadway
Boulder, CO 80305

Job description:

As the lead scientist for the NOAA Earth System Research Lab Aircraft Program, Colm Sweeney’s focus is on overall program development. This includes overseeing the existing network of aircraft sites; developing new ways to ensure data quality, as well as easy access to the data; and developing new tools and platforms for collecting vertical profiles of CO2 and other trace gases throughout North America. These vertical profiles are an essential component of quantifying the net impact that the North American continent has on atmospheric concentrations of CO2 and other greenhouse gases.


Colm received his Ph.D. in 2000 from the Lamont-Doherty Earth Observatory at Columbia University for his studies of biogeochemical processes in the Southern Ocean. He followed this with a three-year tenure at Princeton University during which time he worked with Dr. Jorge Sarmiento, focusing on computer ocean model simulations. In one study Colm used satellite observations of chlorophyll in the surface ocean to predict how absorption of the sun's short wave radiation by phytoplankton might change large scale ocean circulation. In another study Colm combined understanding of large-scale ocean circulation with measurements of carbon-14, both in the atmosphere and the ocean, to better constrain air-sea gas exchange of CO2.

After 13 years as a Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado in Boulder, CO employee, Colm is now working a National Oceanic and Atmospheric Administration (NOAA) employee at the Earth Systems Research Laboratory's (ESRL) in the Carbon Cycle Group. His primary responsibility remains the same and is focused on aircraft measurements of greenhouse gases and other long lived tracers over North America. This program is dedicated to understanding both the transport and surface processes that determine greenhouse gas concentrations throughout the free troposphere (below 25,000 feet). Regular flights from numerous sites across North America, as well as targeted, intensive sampling missions, have provided valuable important validation points for models and given new insights into large-scale transport of atmospheric air masses.

Colm also continues his role as lead scientist for fieldwork in the Southern Ocean, maintaining an ongoing time series of measurements of surface water CO2 from the tip of Argentina to the Antarctic Peninsula. His focus is to establish an understanding of the processes that drive air-sea exchange of CO2 in the Southern Ocean. This research has special significance based on the observations that wind speeds have increased an estimated 15% in the Southern Ocean over the last half century. With a large discrepancy in future predictions of the role the Southern Ocean will play in the global carbon cycle, it is essential that processes controlling surface water CO2 are understood. With data collection dating back to 2001, this has become the longest running time series in the Southern Ocean.