JpGU-AGU Joint Meeting 2017

Presentation information

[EJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG48] [EJ] Science in the Arctic Region

Wed. May 24, 2017 9:00 AM - 10:30 AM 304 (International Conference Hall 3F)

convener:Masato Mori(Research Center for Advanced Science and Technology, the University of Tokyo), Shun Tsutaki(Japan Aerospace Exploration Agency), Shunsuke Tei(Arctic Research Center, Hokkaido University), NAOYA KANNA(Arctic Research Center, Hokkaido University), Chairperson:Naoya Kanna(Arctic Research Center, Hokkaido University)

10:15 AM - 10:30 AM

[ACG48-06] Variability of sea-ice thickness in the northeastern coastal Chukchi Sea revealed by a moored ice-profiling sonar

*Yasushi Fukamachi1, Daisuke Simizu2, Kay I. Ohshima1, Hajo Eicken3, Andrew R. Mahoney3, Katsushi Iwamoto4, Erika Moriya5, Sohey Nihashi6 (1.Hokkaido University, 2.National Institute of Polar Research, 3.University of Alaska Fairbanks, 4.City of Mombetsu, 5.Hydro Systems Development, Inc., 6.National Institute of Technology, Tomakomai College)

Keywords:sea-ice thickness, Chukchi Sea, ice-profiling sonar

Using a moored ice-profiling sonar, time-series ice-draft data were obtained in a coastal region of the northeastern Chukchi Sea during 2009-10 for the first time. Time-series data show seasonal growth of sea-ice draft, which is occasionally interrupted by the appearances of coastal polynya and upwelled Atlantic Water.The sea-ice draft distribution indicates the abundance of thicker ice comparable or less than in the adjacent Beaufort Sea.The rapid increase of thicker ice from December to January corresponded to the minimal offshore drift in January and the resulting rapid decrease of level-ice fraction indicating dynamical thickening processes.The mean draft and its converted thickness are 1.27 and 1.54 m, respectively. Heat losses are calculated with ice-thickness data averaged over various time scales corresponding to various spatial scales. Comparing to the estimate with ice-thickness data every second, these estimates are roughly two thirds and a half for the cases with spatial averaging over ~20 and 100 km, respectively.The heat-loss estimate based on thin-ice data derived from the AMSR-E corresponds well with the estimate based on the 1-second observed ice-thickness data, indicating the validity of a thin-ice thickness algorithm and the resulting heat-loss estimate based on the AMSR-E data.