The Hawaii Ocean Time-series (HOT) program: Background, rationale and field implementation

David M. Karl and Roger Lukas

Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, HI 96822, U.S.A.

(Received 16 March 1995; in revised form 27 September 1995; accepted 12 January 1996)

Abstract

Long-term ocean observations are needed to gain a comprehensive understanding of natural habitat variability as well as global environmental change that might arise from human activities. In 1988, a multidisciplinary deep-water oceanographic station was established at a site north of Oahu, Hawaii, with the intent of establishing a long-term (> 20 years) data base on oceanic variability. The primary objective of the Hawaii Ocean Time-series (HOT) program is to obtain high-quality time-series measurements of selected oceanographic properties, including: water mass structure, dynamic height, currents, dissolved and particulate chemical constituents, biological processes and particulate matter fluxes. These data will be used, in part, to help achieve the goals of the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS) research programs. More importantly, these data sets will be used to improve our description and understanding of ocean circulation and ocean climatology, to elucidate further the processes that govern the fluxes of carbon into and from the oceans, and to generate novel hypotheses. These are necessary prerequisites for developing a predictive capability for global environmental change.