Sustained ocean observations from merchant marine vessels

Merchant marine vessels have provided invaluable information about weather and climate over the seas. In this note, it is shown how these vessels also contribute to ocean research through systematic surveys of upper ocean temperature, salinity and currents. By repeatedly sampling a particular route, one can obtain an accurate picture of the mean state of the ocean and where and how it varies. With a few examples drawn from our own work we show how commercial shipping and cruise vessels, with their unparalleled access to the oceans, could give society far more extensive and valuable information about upper ocean and atmospheric conditions on a regular basis. But for this to happen, a new generation of ocean instrumentation needs to be developed that is optimized for completely automatic and unattended operation on such vessels. It also means working with the merchant marine community to develop guidelines and procedures for future cooperative efforts.