10:45 AM - 12:15 PM
[ACG44-P09] Plan of Observing System Experiments (OSEs) for evaluating the new configuration of the Tropical Pacific Observing System (TPOS)
Keywords:Tropical Pacific Observing System, Observing System Experiment, UN Decade for Ocean Science
The Tropical Pacific Observing System (TPOS) has faced several problems since 2010. For example, observations were suspended because maintenance for many buoys in the TAO array stopped due to budget shortfalls in 2012-2014. Also, for the TRITON array, the number of buoys was significantly reduced. Under these circumstances, the TPOS2020 project, formed under the Global Ocean Observing System (GOOS), studied the design of a new efficient and sustainable TPOS combining various observation platforms, which was released in 2019. The new design will reduce the density of observations outside the equatorial region (2oS-2oN), while extending observation lines along several latitudinal lines to observe subtropical air-sea fluxes, and enhancing observations near the surface, with focusing on atmosphere-ocean interactions. Transition to that design is underway.
Observations of the tropical Pacific are essential for ENSO forecasts and are, therefore, critical for coupled atmosphere-ocean prediction systems used for subseasonal-to-seasonal (S2S) forecasts. The impact of the TAO-TRITON array and Argo floats on ENSO forecasts has been investigated by the Observing System Experiments (OSEs) and reported in TPOS2020 (Fujii et al. 2015). Now, to determine the impact of the TPOS design transition on the coupled prediction systems, the Japan Meteorological Agency, the European Centre for Medium-Range Weather Forecasts, the National Centers for Environmental Prediction, and others are planning to conduct new OSEs. By using as many systems as possible, this activity aims to provide a robust assessment that is less dependent on errors of individual systems. This activity is also coordinated in close collaboration with the UN Ocean Decade Project SynObs; its results will be compared with results of OSEs using higher-resolution ocean prediction systems being planned as part of SynObs. This comparison will provide essential information that contributes to the maintenance and development of the global ocean observation network. The role of observation vessels and shipboard observations in TPOS will also be discussed in the activity.
Observations of the tropical Pacific are essential for ENSO forecasts and are, therefore, critical for coupled atmosphere-ocean prediction systems used for subseasonal-to-seasonal (S2S) forecasts. The impact of the TAO-TRITON array and Argo floats on ENSO forecasts has been investigated by the Observing System Experiments (OSEs) and reported in TPOS2020 (Fujii et al. 2015). Now, to determine the impact of the TPOS design transition on the coupled prediction systems, the Japan Meteorological Agency, the European Centre for Medium-Range Weather Forecasts, the National Centers for Environmental Prediction, and others are planning to conduct new OSEs. By using as many systems as possible, this activity aims to provide a robust assessment that is less dependent on errors of individual systems. This activity is also coordinated in close collaboration with the UN Ocean Decade Project SynObs; its results will be compared with results of OSEs using higher-resolution ocean prediction systems being planned as part of SynObs. This comparison will provide essential information that contributes to the maintenance and development of the global ocean observation network. The role of observation vessels and shipboard observations in TPOS will also be discussed in the activity.