In-situ Observations at Sea, the Voluntary Observing Ship (VOS) Scheme

Since a few years, the cooperation between public and private sector is gaining importance to make more data available.

One example for this is the Voluntary Observing Ship (VOS) Scheme, which uses ships (commercial and private) to acquire and transmit many meteorological and oceanographic parameters. These variables provide essential input to weather warnings and forecasts at sea and at land for more than a century. Nowadays many commercial vessels are already equipped with meteorological and oceanographic sensors to provide the shipping company with data needed for the optimization of the operations of the ship. The VOS network relies on ships sailing all oceans and seas of the world. The ships are recruited by national meteorological services (NMSs) for taking and transmitting meteorological observations. The forerunner of the VOS scheme dates back as far as 1853, when seafaring nations organised the first formal international meteorological meeting to coordinate the weather observing at sea. The United Nations Decade of Ocean Science for Sustainable Development (2021-2030) aims at making and promoting all gathered data accessible and usable to the meteorological and scientific community as well as complementing the NMS operated VOS.

One key characteristic of the VOS network is that the ships and the observers onboard are volunteers, and not professionals. National meteorological services recruit vessels and the crew to a national VOS programme, equip them with calibrated instruments, train the observers, and provide means to code and transmit the weather observations from ship to shore, where the data provides essential input to numerical weather models, forecasts and warnings, as well as climatological applications. The reason for sailors, shipping companies and ship owners for joining the VOS scheme is the profound knowledge that mariners face many hazards while at sea: storms, rough seas, ice and icebergs, and only accurate warnings and forecasts can provide valuable information for safe routing. This important link between these observations and the chance to enhance the safety for life at sea led to the inclusion of weather observations as obligatory within the international convention for the Safety of Life at Sea (SOLAS).

Despite the increasing importance of the data from the VOS scheme, the number of participants has been decreasing in the past years. To compensate this loss, efforts are made to take and generate data from other sources, such as from collaborations with scientific and commercial projects and operational networks. One key task of these efforts is to present the requirements of the operational meteorological community to other groups.

The presentation will give an overview of the VOS network, other global ocean observing networks, show examples of public-private partnerships, and will give an outlook onto the next decade of meteorological and oceanographic observations at sea including 3rd party data.