The Hawaii Ocean Time-series (HOT) program is a long-term oceanographic study based at the University of Hawaii at Manoa.
Scientists working on the Hawaii Ocean Time-series (HOT) program have been making repeated observations of the hydrography, chemistry and biology of the water column at a station north of Oahu, Hawaii since October 1988.[1] The objective of this research is to provide a comprehensive description of the ocean at a site representative of the North Pacific Subtropical Gyre.[2] Cruises are made approximately once per month to the deep-water Station ALOHA (A Long-Term Oligotrophic Habitat Assessment; () located 100 km north of Oahu, Hawaii. Measurements of the thermohaline structure, water column chemistry, currents, optical properties, primary production, plankton community structure, and rates of particle export are made on each cruise. The HOT program also uses Autonomous underwater vehicles, including floats and gliders, to collect data at Station ALOHA between cruises.[3]
The dissolved inorganic carbon data set that has been accumulated over the course of the HOT program shows the increase of carbon dioxide in the surface waters of the Pacific and subsequent acidification of the ocean.[4] The data collected by these cruises are available online.
The HOT program recently celebrated its 20th year in operation and the 200th research cruise occurred in February 2008.[5]