Scientists will use measurements from the CARES campaign to examine how various gases and aerosol particles evolve and mix during the course of a day.Starting this week, dozens of researchers are on location in Sacramento for the Carbonaceous Aerosol and Radiative Effects Study, or CARES. Using a combination of more than 50 instruments at two ground sites and on two aircraft, the team will measure the evolution of black carbon and secondary aerosols in the Sacramento urban air plume. This information will lead to a better understanding of the effects of urban and natural atmospheric particles on climate, and improve atmospheric models that are used to simulate the impact of aerosols on climate change.

Throughout the month of June, research flights by a Gulfstream-1 and King Air B200 will ideally occur twice a day, every other day, with one flight in the morning and one flight in the afternoon. Aircraft operations, coordinated by the ARM Aerial Facility, are based out of McClellan Airport. Each research flight will start over the “T0” ground site at American River College in the Sacramento suburbs and transit over the “T1” site in Cool, about 70 kilometers to the northeast. This is the path of the prevailing winds in June and will allow researchers to measure the evolution of the particles in the atmosphere as they travel and age along this route. Weather balloons will be launched from each site at regular intervals—five launches on fly days—to further define the atmospheric conditions.The Gulfstream-1 (G-1), operated by the ARM Aerial Facility for the Department of Energy, will obtain in situ data sets from the Sacramento urban air plume.

Rahul Zaveri from Pacific Northwest National laboratory is the principal investigator for the campaign, which involves approximately 70 scientists and students from a variety of research organizations and academia. For more information, read the press release and follow the action on Zaveri’s "travelogue"—Rahul CARES.