Dispatch 23: One Last Buoy Recovery: TOP number 4

Ashley Arroyo

October 7, 2023

Dispatch 22: One Last Buoy Recovery: TOP number 4

We are steaming south down the 140°W longitude line towards the continental shelf again to begin another array of coastal CTD/bongo stations (like the Barrow Line in Dispatch 20). This line of stations is called the “Mackenzie Line” or “MK line” for short since these stations are located close to the mouth of the Mackenzie River. Over the past few days, the buoy team has been keeping a close eye on the GPS location of two potential buoys that were candidates to be recovered, as they were in the general vicinity of our cruise track. These buoys were one Ice-Tethered Profiler (ITP number 122) and one Tethered Ocean Profiler (TOP number 4). ITP 122 and TOP 4 were both deployed on the same ice floe (at 79°N 135°W) in September 2021. The two buoys drifted together throughout most of their time in the Canada Basin but started to separate some months ago. In the past week, ITP 122 went rogue and started moving at 80 cm/s, which is very fast considering ITP drift speeds are typically only around 10 cm/s! Some of us were joking that ITP 122 was catching a ride with a speedy whale. It’s still unclear why the buoy is moving so fast, and we may never know. Because of ITP 122’s escape from our vicinity, it no longer made sense to attempt recovering both buoys. So, we set our sights on recovering TOP4 (which happened to be only a few miles out of our way along the MK line).

The recovery was a success! Since the TOP was returning GPS locations every hour, the buoy was easy to track down, and its yellow surface float was spotted without much trouble. A few members of the crew braved the somewhat rough seas in the small boat to hook the TOP so it could be pulled on board and returned to WHOI to be refurbished! The surface buoy was a bit scratched up and mangled – the tell-tale claw marks indicate a polar bear is to blame! The bear probably realized the yellow foam shell of the surface buoy was not quite the snack it was looking for and left it alone before destroying it completely. After all the components of the TOP were brought on board, we continued our steam down the MK line to hit a few more CTD/bongo stations. Once we finish with this group of stations (likely late Sunday night), we will begin our steam back to Cambridge Bay! The 2023 JOIS/BGOS expedition is winding down but don’t worry – we have plenty of science left to go.