Ship-based Repeat Hydrography: a Strategy for a Sustained Global Programme. A Community White Paper developed by the Global Ocean Ship-based Repeat Hydrographic Investigations Panel for the OceanObs ’09 Conference, Venice, Italy, 21–25 September 2009.

Abstract

Ship-based hydrography is the only method for obtaining high-quality measurements with high spatial and vertical resolution of a suite of physical, chemical, and biological parameters over the full ocean water column, and in areas of the ocean inaccessible to other platforms. Global hydrographic surveys have been carried out approximately every decade since the 1970s through research programs such as GEOSECS, TTO/SAVE, WOCE / JGOFS, and CLIVAR. It is time to consider how future surveys can build on these foundations to create a coordinated network of sustained ship-based hydrographic sections that will become an integral component of the ocean observing system.

This white paper provides scientific justification and guidelines for the development of a regular and coordinated global survey. Two types of surveys are required to meet scientific objectives: (1) a global decadal survey conducted such that each full ocean basin is observed over an approximately synoptic time-period (< 3 years), and (2) a sub-set of the decadal survey lines sampled at high-frequency (repeats every 2-3 years). Given the end date of the present sampling programs, a coordinated global survey should begin before 2012 to maintain continuity.