Missing Western Pacific moorings threaten weather and climate forecasting and research
The Tropical Western Pacific Ocean is characterized by some of the warmest seawaters, driving the global atmospheric circulation and climate through the ascending branches of the Walker and Hadley circulations. This region is key for the genesis of El Niño Southern Oscillation, the dominant interannual climate mode with world-wide influence and substantial socioeconomic impacts. Observations of the ocean–atmosphere system in this region are thus crucial to describe, understand, and forecast climate globally, and to better document and interpret intraseasonal variability, the monsoons and typhoon genesis. For more than 40 years, this region has been monitored using a combination of platforms, including satellite and in situ sensors, which together form the Tropical Pacific Observing System (TPOS). One of the key components of the TPOS is the moored array, which offers the unique ability to provide collocated oceanic and surface atmospheric observations at high temporal resolution, as well as long time series for context and accurate statistics. Initially composed of nearly 70 moorings, the TAO/TRITON (Tropical Atmosphere Ocean/Triangle Trans-Ocean Buoy Network) moored array suffered from deterioration to the TAO array in 2012, followed by a decommissioning of the western Pacific TRITON array beginning in 2014. Despite plans and strong recommendations by the community to redeploy and maintain moorings in the Western Pacific, there are currently no near-equatorial moorings deployed west of 165°E and none planned for future deployment. This absence of moorings in the western Pacific poses an immediate risk to the value of a basin-wide TPOS and our ability to observe, understand and forecast ocean–atmosphere coupled variability. This paper discusses the direct and indirect risks that this gap presents for the research and the operational communities, for subseasonal-to-seasonal forecasts and long-term climate change studies. It highlights the urgent need to ensure TPOS robustness in this important region.