El Niño is most readily associated with particularly snowy winters in the Sierra Nevada and Rocky Mountains, but this complex weather pattern and its antithesis La Niña impact weather patterns and climate on both sides of the Pacific, and indeed, around the world, leading to coastal flooding, droughts and wildfires, and shifts in fish stocks that affect the larger ocean ecosystem.
The Tropical Pacific Observation System was developed to monitor oceanographic and meteorological conditions in the region to improve early predictions of major weather events like El Niño and La Niña, which are critical for emergency management and economic planning. The network combines a variety of observation platforms including ship-based surveys, satellites, and a grid of buoys moored to the bottom of the Pacific Ocean to provide the data required to understand environmental phenomena and develop essential global weather forecasts.
The TPOS 2020 project was initiated by the National Oceanic and Atmospheric Administration (NOAA) and 13 science organizations from six countries to redesign the Tropical Pacific Observing System by the year 2020. The cost and complications of maintaining the existing system prompted NOAA and its partners to look for a new tool to maintain and ultimately improve the quality of data.
In September 2017, Saildrone partnered with NOAA to launch a series of six-month missions to the Tropical Pacific to test how unmanned surface vehicles (USVs) could augment TPOS data collection and improve long-term weather forecasting.
Over the past five years, Saildrone USVs have been deployed from San Francisco and Hawaii to survey near the equator, and from Guam to collect data in the Western Equatorial Pacific and collect surface ocean and meteorological measurements in the Kuroshio Surface Current, a western boundary current similar to the Gulf Stream in the Atlantic Ocean.
“We are surprised by how abrupt these fronts are. Some of these warm water fronts are so sharp that the ocean is changing a whole degree in temperature over less than a kilometer."
Megan Cronin, oceanographer at NOAA Pacific Marine Environmental Laboratory
During the first mission, SD 1005 and SD 1006 rendezvoused with the RV Roger Revelle to validate collected measurements. While in the survey area, the saildrones sailed patterns around moored buoys to provide spatial and temporal gradient information as well as validate buoy sensors. The preliminary data revealed findings regarding sea surface temperature shifts previously undetectable by satellite or buoy.