We are just past the mid point in RV Mirai’s 2104 Arctic research voyage. As of noon today 127 standard radiosondes have been launched since we departed Dutch Harbor on the 30th of August. Seven of those also carried ozone sensors and another seven dedicated ozone sensor balloons. Five HYVIS balloons have been launched. There have been sixty CTD/rosette casts, thirty-seven expendable CTDs launched, 119 TurboMap casts, three multi-core sediment samples taken and two Surface Velocity Profiler buoys deployed. The research will not end when we depart the Fixed Point Station on 23rd of September. Numerous other stations will be occupied and other observations will be made to further collect valuable data. Only the intensity will reduce somewhat as we begin to think about heading back across the Pacific to conclude this voyage in Yokohama on the 10th of October.
We have not been alone in this research cruise. Also in the Beaufort/Chukchi Sea region Canada’s icebreaker/research ship CCGS Amundsen and Korea’s Araon have also been hard at work. Amundsen steamed close by on the 17th, whistles were blown and photos taken as she passed by, fittingly I thought for two Arctic research ships, in the midst of a snow squall. I chatted with Amundsen’s Captain Alain Gariépy on VHF as they had just completed recovery of one of two JAMSTEC moorings and were headed to recover and replace the second mooring before returning to the pack interface for other studies before heading eastward and home to Quebec later this month.
Thus far for Mirai we have seen little ice. That is of course by design, as the Chief Scientist wanted a location that he could maintain for two to three weeks without the threat of being pushed off station by ice. Generally, the pack edge has been further south than in the first few years of this decade. 2013 and 2104 have been bucking the trend of “least ice years”, part of the cyclical nature of sea ice regardless of global climate change.
Locally, as an Ice Navigator, I have found it interesting that we began our voyage concerned with a tongue of ice that extended eastward from the polar pack well west of our planned fixed point of observation and over the last week we have been circled by another tongue of ice extending eastwards from the pack on the other side of our fixed point. The first eastward pointing mass moved predominantly under the influence of the Beaufort gyre, that ever-present Arctic ocean current that rotates in a counter clockwise motion, generally driving what ice that is present in the Arctic Ocean towards the Canadian Archipelago. The second mass of ice was driven by the consistent east winds that have been blowing for several days now as a low sits more or less stationary to the north of us. Winds have been east of northeast 20 kts and above since 14th. These have been two totally different contributors to sea ice movement. We have seen some ice, isolated ice cakes less than 10m across, rotting old ice, but nothing substantial.
Sitting under the influence of the stationary low these last few days, we have been enduring strong easterly and northeasterly winds, which yesterday were up to 40 knots. Seas have been between two and three and a half metres but still RV Mirai continues to successfully complete overside CTD/rosette casts. She is a very sea kindly ship, and since she is fitted with twin screws, two bowthrusters and a stern thruster she can safely maintain station in conditions that would challenge other ships. That combined with the very effective active roll stabilizing system make for an extremely effective ocean research platform.