OPEN OCEAN MOMENTUM FLUX MEASUREMENTS IN MODERATE TO STRONG WINDS
OPEN OCEAN MOMENTUM FLUX MEASUREMENTS IN MODERATE TO STRONG WINDS
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DOI：
10.1175/1520-0485(1981)011
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发表时间：
1981-01-01
影响因子：
3.5
通讯作者：
POND, S
中科院分区：
文献类型：
--
作者：
LARGE, WG;POND, S
在Bedford海洋研究所的深水稳定塔上，用雷诺通量法和耗散法测量了动量通量，用改装的Gill螺旋桨-叶片风速计测量了动量通量。由196个雷诺通量测量得到的阻力系数与Smith(1980)根据同一地点的独立观测得到的结果吻合得很好。结果表明，在风速为4~20m的S−1风速范围内，耗散和雷诺通量的计算结果具有很好的一致性。使用更广泛的耗散资料集(塔的1086h和气象船PAPA的505h)研究了阻力系数与风速、风速和稳定性的关系。阻力系数减小到10m高度和中性条件(CDN)，与稳定性和风速无关(对于Fetch/Height≳80 0)，但随着风速大于10m S−1而增大。平均而言，CDN被观察到较小。在大风期间而不是在逆风期间或在风向改变之后。根据我们的结果和其他人的许多深水结果，我们得到了U10是10m高度的风速，并给出了由该CDN和10m以外高度的风速和地面负气温观测得到的应力的计算方法。
Measurements of the momentum flux were made by the Reynolds flux and dissipation methods on a deep water stable tower operated by the Bedford Institute of Oceanography, A modified Gill propeller-vane anemometer was used to measure the velocity. Drag coefficients from 196 Reynolds flux measurements agree well with those reported in Smith (1980) based on independent observations at the same site. Based on 192 runs, a comparison of the dissipation and Reynolds flux results shows excellent agreement on average, for wind speeds from 4 to 20 m s−1. The much more extensive dissipation data set (1086 h from the tower and 505 h from the weathership PAPA, CCGSQuadra) was used to investigate the dependence of the drag coefficient on wind speed, fetch and stability. The drag coefficient reduced to 10 m height and neutral conditions (CDN), is independent of stability and fetch (for fetch/height ≳800) but increases with wind speed above 10 m s−1. Some time series of the momentum flux and drag coefficient are shown to demonstrate additional sources of variation in the drag coefficient. CDN is observed to be smaller, on average. during rising winds than during failing winds or after a change in wind direction. Based on our results and many deep water results of others, we obtainwhereU10 is the wind speed at a height of 10 m. A method for calculating the stress from this CDN and observations of wind speed and surface minus air temperature at heights other than 10 m is also given.