Stratus Ocean Reference Station Successfully Deployed Off Coast of Chile
On January 28, 2021 the 19th deployment of the Stratus Ocean Reference Station (ORS) was accomplished using the Chilean Navy Ship AGS 61 Cabo de Hornos. The Stratus ORS is located about 800 nautical miles off the coast of northern Chile, at 220 31’ S, 850 48’ W, where the ocean depth is 4,230 meters, or more than 2.6 miles. This ocean reference station is named after the persistent stratus clouds found west of Chile and Peru, which affect the ocean and atmospheric conditions in the eastern Pacific and impact the climate of this region. The Stratus ORS is a well-instrumented surface mooring deployed in a data-sparse region of the eastern South Pacific. Taking measurements in this region is important because climate models have warm sea surface temperature biases and can have significant errors in their representation of the exchange of heat, freshwater, and momentum between the ocean and atmosphere. More accurate models and better understanding of air-sea interactions and exchanges of indicators like temperature and carbon can improve predictions of weather and climate events and help assess ecosystem health.
Woods Hole Oceanographic Institution (WHOI) has been working with the Chilean Navy, or Armada de Chile to service the Stratus mooring since 2015. The Cabo de Hornos ship is based out of Valparaíso, Chile, in the First Naval District and is also home to the Servicio Hidrográfico y Oceanográfico, or SHOA, an agency similar to NOAA. WHOI typically sails with 4-5 people, and also includes Chilean Academics and SHOA staff on cruises for assistance and research opportunities. On this mission, they were able to service the Stratus ORS, which requires recovering the old mooring and replacing it with a new one. Moorings are typically replaced every 12 months, and the 18th Stratus ORS had been deployed in April 2019, meaning it was stationed for almost 2 years before it could be replaced.
The Status ORS deployment and recovery was originally scheduled for March 2020, but due to COVID-19 pandemic, this cruise was rescheduled two times. In each of these instances, gear was shipped to Valparaíso in preparation for the cruise and then shipped back to WHOI. When the Cabo de Hornos became available in late January 2021, NOAA and WHOI moved swiftly to plan for travel, quarantine stays, and COVID-19 testing to meet WHOI, NOAA, and Armada de Chile protocols. The cooperation of the Armada de Chile and of the ship’s officers and crew was essential to the mission’s success. The Stratus ORS is supported by NOAA’s Pacific Marine Environmental Laboratory and Global Ocean Monitoring and Observing Program through our Cooperative Institute CINAR.