1. Chemistry and Composition of the Atmosphere, including the exchange of important trace gases between ocean, land and atmosphere, as well as chemical tranformation within the atmosphere.

UCI in-house research includes atmospheric measurements of trace gases (Blake, Cicerone, Rowland), stable and radioisotope distributions (Trumbore, Tyler), surface source and sink characterization (Reeburgh, Tyler, Cicerone), kinetics of gas phase and heterogeneous chemical reactions (Benter and Finlayson-Pitts), and a new capability in atmospheric biogeochemistry with the filling of an open position for an atmospheric chemist at the full professor level in ESS.  Also included are documented and well-published 3D tracer transport models of atmospheric chemistry at regional and global scales (Dabdub, Prather). Pooling our collective resources to link global trace gas distributions, information that about production and consumption processes, and  atmospheric chemical transport models will provide better understanding of the spatial and temporal distribution of sources and sinks for many important trace gases.  For example, a particular focus already developing is the coherent study of methane and the related natural halocarbons and their isotopes.  Improved understanding of the changing global budgets for these gases will come from efforts underway involving source characterization, 3-D modeling, and kinetic effects for these gases.

2. Biogeochemical Cycling, defined as the internal transformations of nutrients and energy on land and in the ocean, and including the transfers between the two.

Two researchers at UCI use new eddy covariance methods to study the exchanges of energy, water and carbon between ocean (Friehe) and land (Goulden) surfaces and the atmosphere.  The transfers of trace gases, energy and water at the land-air and ocean-air interface are controlled by complex interactions of atmospheric turbulence, boundary-layer development, and biological and chemical modification of air in contact with the surface. We can see major advances with the addition of collaborators measuring trace gas exchanges (for example, sulfur and nitrogen gases, methane, and the methyl halides; Blake, Cicerone, Reeburgh, and new atmospheric chemist), isotopes (Druffel, Trumbore, Tyler), and in studying biological and chemical processes affecting the rate of production and consumption at the land and ocean surfaces (Cicerone, Reeburgh, Trumbore).  A major interaction between the land, atmosphere and ocean is in the transfer of water (Famiglietti).  We will link hydrologic models to estimates of biogeochemical cycling, including trace gas emission, on land.  In addition, one eddy flux tower facility installed by Goulden at the San Joaquin Marsh UC Reserve, provides a secure, low-cost platform for testing new measurement methods and equipment, and for teaching students field data collection and manipulation.

3. Dynamics of Oceans, Atmosphere, and Climate

Our efforts in dynamics will focus on feedbacks within the climate system, with the ultimate goal of analyzing components of a typical climate system model.  We will use both data and numerical models to investigate the specific processes governing the climate system.  For example, changes in chemistry (Prather) and aerosol distribution (Zender)  can be used to refine radiative forcing estimates for atmospheric general circulation models (AGCMs).  The representation of Rossby wave breaking in a hierarchy of high-resolution atmospheric models (Magnusdottir) will help in parameterizing its effect in standard resolution AGCMs.  The influence of varying winds on upwelling rates in the tropical Pacific will be explored using high-resolution coral data sets along with instrumental and satellite data records (Druffel, Primeau).  In situ measurements of ocean-atmosphere and land-atmosphere heat, momentum, water, and trace gas exchanges (Friehe, Goulden) are key requirements for determining how micro-meteorology can influence large scale atmospheric and oceanic circulation (Magnusdottir, Primeau).  Finally, efforts to understand the atmospheric response to sea surface temperature and sea ice forcing  (Magnusdottir) and the ocean response to wind forcing (Primeau) are essential for refining coupled ocean-atmosphere models.  Ultimately, the results from our process studies are likely to provide information necessary to improve specific components of full-scale numerical climate models under development at other IGPP centers (LANL, LLNL, UCLA) and elsewhere (the National Center for Atmospheric Research).