Dispatch 22: Deployment of Mooring D
Ashley Arroyo (Yale University)
September 20, 2024
16:30 UTC, 74°N 140°W
Conditions:
- Mostly sunny
- 0% sea ice cover
- -0.5°C
- Winds 7.5 knots northwesterly
- Sunrise: 20-Sep-2024 08:48:33 -06
- Sunset: 20-Sep-2024 21:40:36 -06
- Day length: 12h 52mn 3s
This morning, the team from Woods Hole Oceanographic Institution (WHOI) and the deck crew deployed the third and final BGOS mooring of this year’s expedition, Mooring D. The operation went smoothly, with the parts of Mooring D lowered off the deck in the opposite order as they were recovered in, beginning with its anchor and bottom pressure recorder, its profilers (which measure temperature, salinity, and pressure), its CO2/pH sensor, and lastly, its yellow flotation sphere which contains an upward looking sonar that provides estimates of sea ice thickness. Once Mooring D was deployed, the Louis began its ~12-hour long southward steam down the 140°W longitude line towards the Alaskan coast, where we will complete our second line of coastal stations, the “MK-Line” (named for its proximity to the Mackenzie River).
The science team took advantage of the long transit time by testing out some Underway CTD casts (UCTD), which involves deploying a CTD probe (which measures temperature, salinity, and pressure) attached to a line off the stern of the ship. Unlike typical CTD casts, UCTD casts can be achieved when the ship is steaming, if the ship’s speed it kept to 12 knots or less. Chief scientist Sarah Zimmermann led the UCTD efforts by completing casts before supper and around 10:30pm. We will arrive at the first station of the MK-Line around 2:00am tomorrow, where the back-to-back CTD/bongo stations will begin!
