Measurements of the Turbulent Oceanic Boundary Layer under Sea Ice

(1)对1990年4月下旬哈德逊湾东南部陆坚冰摩擦边界层的三维流、温度和盐态进行了测量。利用三维超声测流仪和电导率-温度传感器连续记录了日潮期边界层内的电流、动量、热通量和盐通量的时间序列。结果表明，比潮汐更高频率的电流变化与动量通量的变化相对应，边界层的流动形式可能会从平滑流动到粗糙流动的间歇性变化。(2)三维超声湍流测量。1991年5月，在阿拉斯加的Elson泻湖上，在一个大约2.2 x 2.2米的冰面上的人工水池和相对光滑的冰雪覆盖的冰面上，风速温度计对动量和热通量进行了估计。结果表明，池上海冰形成后，热通量系数减小，随着海冰厚度的增加，热通量系数逐渐增大。可以认为，0.4 m高度的测量是在水池上方的内边界层内进行的，而0.96 m高度的测量可能会受到实验场地迎风面光滑的冰雪覆盖的影响。(3) 1992年2月中旬至3月中旬，在北海道Saroma泻湖一个约3 × 3米的人工水池上，通过海冰同时测量了大气和海洋边界层。将结合冰的生长，对开放水域和池上薄冰的动量、热量、二氧化碳和盐通量进行估算。这些数据正在分析中。

(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.