Measurements of the Turbulent Oceanic Boundary Layer under Sea Ice

(1)1990年4月下旬，对哈德逊湾东南部陆冰下摩擦边界层的三维流、温、盐场进行了测量。利用三维超声波海流计和电导率-温度传感器，在一天的潮汐周期内连续记录了边界层中的海流、动量、热量和盐通量的时间序列。结果表明，在比潮汐频率更高的频率下，水流的变化与动量通量的变化相对应，边界层内的流型可能会间歇性地从光滑流向粗糙流转变。(2)三维超声湍流测量。1991年5月，在阿拉斯加Elson泻湖的一个约2.2×2.2米的人工冰上和相对光滑的积雪覆盖的冰上，得到了风温计估计的动量和热通量。结果表明，在水池上形成海冰后，热流系数减小，随着冰层厚度的增加，热流系数逐渐增大。可以认为，0.4m高度的测量是在池上方的内边界层内进行的，而0.96m高度的测量可能受到实验场光滑的积雪逆风的影响。(3)1992年2月中旬至3月中旬，在北海道Saroma泻湖约3x3m的人工水池中，通过海冰同时进行了大气和海洋边界层的测量。将结合冰的增长，对开阔水域和池中薄冰的动量、热量、二氧化碳和盐通量进行估计。这些数据一直在分析过程中。

(1)Measurements were made of the three-dimensional current, temperature and salt regime in the frictional boundary layer under Landfast ice in southeast Hudson Bay during late April, 1990. Time series of currents, momentum, heat and salt fluxes were continuously recorded in the boundary layer during a diurnal tidal period by a three-dimensional ultrasonic current meter and a conductivity-temperature sensor. It was indicated that variations in current at higher frequencies than tides corresponded to those in momentum flux, and that the flow regime in the boundary layer might change intermittently from smooth to rough flow.(2)From turbulence measurements by a three-dimensional ultrasonic. anemometerthermometer estimates of momentum and heat fluxes were derived over both an artificial pool on the ice, approximately 2.2 x 2.2 m and over relatively smooth, snow-covered ice on Elson Lagoon, Alaska in May, 1991. It was indicated that the heat flux coefficient decreased after sea ice was formed on the pool, and that it then increased gradually with an increase in ice thickness. It can be considered that the measurements at 0.4 m height were made within the internal boundary layer over the pool, while those at the 0.96 m height might be affected by the smooth, snowcovered ice upwind of the experimental site.(3)Simultaneous measurements of both atmospheric and oceanic boundary layers through sea ice were made at an artificial pool, approximately 3 x 3 m on Saroma Lagoon, Hokkaido during mid-February to mid-March, 1992. Estimates of momentum, heat, CO2 and salt fluxes will be derived for both open water and thin ice on the pool in conjunction with ice growth. Those data have been in process of analysis.