Dispatch 24: Wrapping up CTD operations
Ashley Arroyo (Yale University)
September 22, 2024
16:00 UTC, 69.65°N 138.91°W
Conditions:
- Mostly cloudy
- 0% sea ice cover
- 8°C
- Winds 14.1 knots northeasterly
- Sunrise: 22-Sep-2024 08:57:33 -06
- Sunset: 22-Sep-2024 21:21:26 -06
- Day length: 12h 23mn 53s
Early this morning, the nighttime watch-standers completed the last two CTD rosette casts of the MK-Line, which marked the official end of CTD operations that were planned for the 2024 BGOS/JOIS expedition! The last station was CB-28aa, which was only 56-meters deep. Although the rosette houses 24 10-liter Niskin bottles, it was only necessary to fire 7 bottles to sample the entire shallow water column. After the completion of station CB-28aa, the Louis steamed toward Herschel Island to quickly recover and deploy a surface mooring that is maintained by the Institute of Ocean Sciences (IOS). After mooring operations were completed, the science crew did one last CTD rosette cast to compare the water samples to the mooring data, which marked the actual last rosette cast of this year’s expedition. Over the course of the expedition, the science team completed a total of 61 CTD/rosette casts, with water samples taken from 1187 Niskin bottles! The water samples included measurements for properties including oxygen, carbon, nutrients, salt, chlorophyll, oxygen isotopes (18O), biotoxins, organic matter, ammonium, and DNA.
The Louis is now steaming toward Amundsen Gulf where we will enter the Canadian Archipelago on our voyage back towards Cambridge Bay where we will disembark from the Louis on Thursday morning.
