Uncrewed surface vehicles arrive at the equator to monitor El Niño development

A map of saildrone operations in the Pacific Ocean. Credit: NOAA, Saildrone

The 120-day Tropical Pacific Observing System (TPOS) 2023 Saildrone Mission officially began on June 22, 2023, just after the official start of what experts suggest may be a strong El Niño. The three Saildrone, Inc. Explorer-class Uncrewed Surface Vehicles (USVs), launched from Honolulu, Hawai‘i, are now at the equator in the central Pacific (~155°W), about 1,300 miles south of the Hawaiian Islands. An El Niño state occurs when above-average equatorial sea surface temperatures are present throughout the central and eastern tropical Pacific, leading to a weakening or even reversal of the trade winds near the equator and anomalous weather patterns across the world. 

Each USV is outfitted with a suite of sensors to monitor wind stress, air-sea exchanges of heat and carbon dioxide, and surface seawater temperature, salinity, and biogeochemistry. In addition, two of the drones will profile ocean currents to about 100 m depth, while the third will profile the distribution of organisms on a range of trophic levels down to 1,000 m depth.