NIWA’s Kaharoa sets sail to deploy robots across the Pacific Ocean


NIWA research vessel Kaharoa will depart Wellington on Friday 12 October to deploy 120 Argo robotic instruments across the Pacific Ocean.

Argo is an observation system for the Earth's oceans. It consists of over 3000 profiling floats, deployed worldwide. Twenty-seven countries are involved in their deployment.

NIWA's Argo voyages are a collaborative effort between NIWA; the Scripps Institution of Oceanography; the University of California, San Diego; the University of Washington; and Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Currently, about 3500 profilers are collecting measurements. The probes automatically descend as far as 2000 metres before rising back to the ocean surface, profiling the temperature, pressure and salinity of the water on the way. The data are transmitted every ten days via satellite to scientists on shore.

Dr Dean Roemmich of Scripps says scientists in Japan and the US are currently testing instruments that can descend to deeper depths of four and six kilometres, respectively.

On board Kaharoa will be US, Australian, and New Zealand equipment. During the voyage, twelve profilers will be deployed for CSIRO, 52 for the University of Washington, 49 for Scripps, and two for NIWA.

Dr Susan Wijffels of CSIRO and Dr Roemmich lead the program, which began as a pilot project in 1999.

Eight hundred one-metre-tall profilers are deployed annually to maintain the global array.

Kaharoa will conduct these deployments between latitudes 28 and 46 degrees South, between New Zealand and South America. The voyage will take two months. Once deployed, the profilers drift with currents and eddies.

Kaharoa is a small scientific research vessel that has conducted international marine scientific research for over 20 years. It has contributed in a very significant way to marine sciences, and in particular to the international Argo programme by deploying profilers away from commercial shipping routes. In doing so, NIWA's Kaharoa has been vital to profiler coverage in the Southern Hemisphere.

This is Kaharoa's 13th Argo voyage, and at the end of the voyage around 1100 profilers will have been deployed from it.

"Argo data are invaluable for informing governments, science and the community on inter-annual variability such as El Niño, as well as decadal and multi-decadal changes in the global ocean," says Dr Roemmich.

For comment, contact:

Dr Phil Sutton,
NIWA Research Oceanographer

Dr Dean Roemmich,
Scripps Institution of Oceanography, University of California, San Diego

To illustrate this story, download a graphic and images from:




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Physical Oceanographer
Argo float cycle.
Research subject: Coasts