New data on change in ice thickness in the Arctic Ocean

Abstract

Ice thickness is a parameter of sea ice cover that is most difficult for mass measurements [1]. Much attention has recently been given to the development of measurements with use of aircrafts, satellites, or under-ice underwater vehicles [2]. At the same time, more capabilities arise for the ice thickness measurements from the icebreakers and ships of icebreaker-type during their frequent voyages in high latitudes of the Arctic Ocean. The voyages of the Soviet atomic icebreakers to the North Pole started in August 1977, when the atomic icebreaker Arktika reached the North Pole [3]. The next one was the voyage of the atomic icebreaker Sibir in the spring of 1987 [4]. Since 1990 such voyages have become more regular not only for icebreakers, but also for other types of ships. The decrease in the ice cover in the Arctic Ocean has allowed the expeditions of the AARI research vessel Akademik Fedorov of the super ice class in the high latitudes to be arranged [5]. Specialists in the field of sea ice study from the AARI who participated in the first voyages of icebreakers in the high latitudes suggested a simple method for visual estimation of the ice thickness during the icebreaker’s movement with a measuring rod, put on the shipboard. The method consists of estimation of the thickness of ice fragments, laid on the edge due to the icebreaker movement. This method was used to estimate the ice thickness during the voyages of the Arktika and Sibir icebreakers in 1977 and 1987, accordingly, from the edge-ice zone towards the North Pole and back.