New Mobile Atmospheric Laboratory Gathering Weather and Climate Change Data on the California Coast
Are Aerosols Reducing Coastal Drizzle
and Increasing Cloud Cover?
June 30, 2005

PT. REYES STATION, CALIF. – Scientists sponsored by the Department of Energy are conducting a six-month atmospheric research campaign at the Point Reyes National Seashore, in Marin County, California.  The experiment’s goal is to help researchers understand how aerosols —small particles such as soot, dust and smoke—influence the structure of marine stratus clouds, and how aerosols are associated with drizzle – the misty rain regularly produced by these types of clouds.  The scientists think aerosols, which can come from both natural and manmade sources, may be reducing coastal drizzle while increasing cloud cover.

Marine stratus clouds are thin, low-level clouds that cover the sky like a blanket.  They are some of the most prevalent clouds on earth, and are an important component of the earth’s climate system.  Despite their importance to the earth-ocean-atmosphere system, relatively few comprehensive data sets about marine stratus clouds are available for scientists to draw firm conclusions related to aerosol effects.  To obtain more, and better, data, researchers need to go to the source.  The department’s Atmospheric Radiation Measurement (ARM) Program is helping them do just that. 

Since the Pt. Reyes field campaign began in March, a new $1.4 million ARM Mobile Facility – a portable atmospheric laboratory with sophisticated instruments and data systems – has been stationed about one mile from the beach, collecting data from the clouds as they move onshore.

Starting in July, activities intensify as two research aircraft —sponsored by DOE’s Atmospheric Science Program and the U.S. Office of Naval Research—join the campaign.  These instrumented aircraft will obtain in-situ measurements of cloud properties, suspended particles and other atmospheric variables needed to analyze aerosol properties of the marine stratus clouds.  The aircraft data will be used to examine the regional characteristics of the marine stratus clouds being sampled at Pt. Reyes and to examine specific links between aerosol chemistry and cloud structure.