To Build an Ocean

The wild oceans can make a poor control group for scientists trying to study how they interact with the sky. Simulating the oceans in mere glass beakers just doesn’t do them justice.

So researchers in the Department of Chemistry and Biochemistry and Scripps Institution of Oceanography at UC San Diego will create a happy medium in a quest to understand prevailing mysteries about how chemistry influences climate and atmospheric processes. They will build their own ocean and atmosphere on the Scripps campus.

A $1.5 million National Science Foundation award created the Center for Aerosol Impacts on Climate and the Environment (CAICE). Center investigators will determine how the chemical composition of aerosol particles and the chemical reactions occurring at their surface impact Earth's climate. The award, which in later phases could direct as much as $40 million toward the center, will support the modification of an existing wave tank at the Scripps Hydraulics Laboratory to create CAICE's research centerpiece, a closed chamber that can simulate ocean-atmosphere interactions. Researchers will add various atmosphere-changing ingredients - from carbon dioxide to phytoplankton to varying levels of light - to measure the effects of different variables.

"We're going to build an ocean and then we're going to build an atmosphere over the ocean," said the center's principal investigator Kim Prather, an atmospheric chemistry professor who holds appointments in the UCSD Department of Chemistry and Biochemistry as well as at Scripps Oceanography. "We'll be able to do all kinds of experiments in this microcosm."

The test tank, currently used to generate waves for fluid dynamics studies, could be ready for the center's experiments by January 2011.

"We're going to understand how real systems behave and how chemistry affects climate," said Prather. “This knowledge will be used to dramatically improve the representation of aerosol chemical mechanisms in global climate models, and how they impact climate processes such as cloud formation, cloud lifetime, precipitation patterns, and direct aerosol absorption.”

Until now, studies focused on determining the impact of aerosol chemical processes on climate have been conducted on either highly simplified model systems in the laboratory, making extension to real-world conditions challenging, or under overly complex atmospheric conditions, making deduction of the underlying driving mechanisms cloudy. As a result, chemical processes associated with aerosol particles are poorly constrained in most computer models used for climate predictions.

"We're understanding at a fundamental level when chemistry is important," said Prather.

The center will include research led by investigators in UCSD's Department of Chemistry and Biochemistry and Scripps who represent fields ranging from fundamental chemistry to biological, chemical, and physical oceanography. Co-investigators and advisors from the Department of Chemistry and Biochemistry include Timothy Bertram, Mario Molina, Robert Pomeroy, Francesco Paesani, and Mark Thiemens. Scripps co-investigators and advisers include Grant Deane, Lynn Russell, Lihini Aluwihare, Brian Palenik, Andrew Dickson, and Veerabhadran Ramanathan.

CAICE will also feature an educational component that will be integrated into science education programs at Birch Aquarium at Scripps. Prather said a key focus of the center will be to reinvigorate K-12 science education through environmental measurements. The initial educational partners include Paul Ecke Central Elementary School in Encinitas and Castle Park High School in Chula Vista, two schools that are working with UCSD scientists to incorporate related marine and atmospheric studies into their science curricula using the center's outreach budget. National Instruments, Horiba, TSI, Inc., and Nanocomposix are the initial industrial partners of CAICE and will provide state-of-the-art measurement tools. Efforts are under way to identify other key outside collaborators and partners to work on scientific issues, as well as educational and outreach activities.

• Robert Monroe