Collaborative Research: The Cariaco Basin Oceanographic Time Series Program

University South Carolina Research Foundation, Columbia SC

Investigators

Abstract

ABSTRACT OCE-0326268 / OCE-0326175 / OCE-0326313 This project constitutes the continuation of the Cariaco Basin Oceanographic Time Series Program (CARIACO). The research team is composed of investigators from the University of South Florida, State University of New York at Stony Brook, and the University of South Carolina at Columbia in the United States and their Venezuelan colleagues at Fundacion La Salle, Universidad Simon Bolivar, Universidad de Oriente, Centro de Procesamiento de Imagenes, and CONICIT/FONACIT. CARIACO collects systematic oceanographic measurements at 10'30' N, 64'40' W in order to understand the relationships between changes in climate, hydrography, and sediment production and accumulation in the Cariaco Basin. Cariaco is a 1,400-m deep depression on the Venezuelan continental margin that is openly connected to the surface Atlantic Ocean above a shallow (~140 m) sill. Because turnover of basin waters is slow, decomposition of sinking material leads to permanent anoxia below about 275 m. An excellent sediment record that is widely used to study Holocene and late Pleistocene changes in climate is preserved in this natural sediment trap. In this context, the time series provides information on modern biogeochemical processes that will serve as a basis for accurately interpreting this sediment archive of climate change. Data collected under this program and results are publicly available via an Internet server (http://imars.usf.edu) upon passing quality control, within periods ranging from weeks to 24 months depending on the difficulty of processing an observation. Data, samples, and bunk space on cruises are also routinely made available upon request. Continuation of the CARIACO program is expected to yield (1) a time series of variability in upwelling of Subtropical Underwater in the Cariaco Basin, including lateral motion, and its impact on primary productivity and vertical flux of particulate matter; (2) the first direct calibration and concurrent cross-reference of various proxies of sea surface temperature (and therefore of paleotemperature) of the Cariaco Basin; (3) clarification of the relative importance of near-surface biological processes, lateral transport, and chemoautotrophy as sources of particulates, (4) an assessment of whether variability in particle flux is driven primarily by local winds or by regional oceanographic processes at the scale of the Tropical Atlantic, and (5) an evaluation of whether changes in nutrient availability or limitation result in major ecosystem regime shifts. This program will fully utilize available satellite observations and meteorological records for the region. CARIACO is an IGBP-LOICZ (Land-Ocean Interactions in the Coastal Zone) program with objectives that are relevant to the "U.S. Carbon Cycle Science Plan" and the OCTET (Ocean Carbon Transport, Exchanges and Transformations) planning initiatives. In this sense, the time series will help elucidate the connection between ocean processes and phenomena like climate change, which operates on a variety of time scales including those relevant to society, and which many scientists think is intricately linked to the tropics. CARIACO measurements may also for example help understand processes that affect regional fisheries and catastrophic weather patterns. An important contribution is the infrastructure for third parties to establish complementary or independent interdisciplinary process studies in the Cariaco Basin. The impact of results from such studies combined with those from CARIACO will be much larger than those possible from individual studies. The time series program also has technology transfer and human resource development impact in Latin America. The program nurtures scientific cooperation with Venezuela, a country of strategic importance to the United States. The program has been maintained through a collaborative effort between the University of South Florida, University of South Carolina, Stony Brook University, Fundacion La Salle, Universidad Simon Bolivar, Universidad de Oriente, Centro de Procesamiento de Imagenes, and CONICIT/FONACIT, with the latter five institutions located in Venezuela. This has provided an opportunity for Venezuelan and other regional scientists to participate in logistics planning, fieldwork, data analysis, and joint publications within a large program, and to participate in a project that addresses issues of both local and global relevance. This program has significant educational impact on minority students in the U.S. and on students and scientists in the Caribbean and Latin America. The Venezuelan government considers CARIACO the most significant oceanographic research program ever conducted in Venezuela.