Measurement of suspended particulate matter under sea ice using ADCP and LISST

초록

Ice-camp measurement has been conducted to investigate the dynamic behavior of suspended particulate matters (SPM) under the sea ice in the Chukchi Sea. Main objectives are (1) to report the role of summer sea ice in releasing SPM into the water column, and (2) to estimate the vertical and temporal variation in size and settling flux of SPM under sea ice using novel holographic and acoustic techniques. Mooring observation of hydrography, hydrodynamics and suspended particles distribution under a drifting sea ice revealed the mixing and entrainment pattern in the upper mixed layer of the marginal ice zone. The ice floe where the mooring system was installed drifted as near-inertial motion with approximately 12-h cycle. Due to the high melt rates of the sea ice during the summertime, a large amount of particulate matters embedded in the sea ice were released into the underlying water column. SPM concentration under the sea ice fluctuated in the range of 60–100 mg l-1 during the mooring period. Results suggest that combined effects of the increase in insolation, ice algal production, and the decrease in ice and snow cover and multi-year sea ice extent could create favorable conditions for enhancing the concentration and flux of SPM during the summer season. During the presentation, the preliminary data collected from 2014 summer ice camp study (ONR-MIZ) will be also presented.