German research vessel Polarstern has retrieved a CAGE methane sensor from 2600-meter water depth in the Fram Strait.
Text: Maja Sojtaric
“The main motivation for our participation in the Polarstern cruise was to install the sensors on a deep lander at Hausgarten, and acquire long term observations of methane concentrations and variations in water masses.” says PhD candidate Pär Jansson who participated in the expedition last year.
Important reference site
Hausgarten is a network of 21 moorings and observatories at water depths ranging between 250 m and 5500 m in the Fram Strait. RV Polarstern has revisited the observatory annually for the past 18 years, collecting long-term ecological data sampled by different instruments throughout the network.
RV Polarstern retrieved CAGE sensors earlier this summer providing long-term observations of methane release in the Arctic Ocean.
Data sampling of methane on the deep lander started on August 14th 2015 and the sensors were successfully recovered on June 26th this year, providing a long data time series.
” This will give CAGE researchers a better understanding of the natural yearly methane variations. The data from the central Hausgarten site will mainly serve as a reference for CAGE observatories in the shallow waters, as the methane sensor was deployed in an area where no deep-water gas hydrate has been found and no methane seepage has been previously observed.” concludes Jansson.
This work was conducted within the FixO3 project, which seeks to integrate European open ocean fixed-point observatories.