Monsoon effects in the Bay of Bengal inferred from profiling float‐based measurements of wind speed and rainfall
Monsoon effects in the Bay of Bengal inferred from profiling float‐based measurements of wind speed and rainfall
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DOI：
10.4319/lo.2008.53.5_part_2.2080
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发表时间：
2008-09
影响因子：
4.5
通讯作者：
S. Riser;J. Nystuen;A. Rogers
中科院分区：
文献类型：
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作者：
S. Riser;J. Nystuen;A. Rogers
降雨和风都有声学特征，可以在海面以下的海洋深处辨别出来。我们研究的降雨量和风速的观测收集在孟加拉湾的深度为600米，从一个专门修改的阿尔戈剖面浮动。除了正常的阿尔戈传感器外，浮标还携带了一个被动声学监听器传感器包，该传感器包每隔几分钟就监测沿着浮标轨迹的声学噪声频谱，并使用一套现有的算法从这些噪声频谱中估计风速和降雨率。将声学得出的风速和降雨量估计值与类似的卫星数据（来自热带降雨测量使命的降雨量和QwikScat风）进行比较，显示两种情况下的总体一致性，尽管基于浮子的测量值代表浮子周围几公里的条件，而遥感观测值在更大的长度尺度上进行了平滑处理。孟加拉湾的强季风信号清楚地存在于基于浮动的风和降雨数据中。浮子测量的近地表盐度因降雨事件和靠近主要河流的强烈沿海径流而变化。在Price-Weller-Pinkel混合层模型版本中模拟了上层海洋温度和盐度的浮动剖面，以及风和降雨的影响，该模型表明大多数降雨事件的直接影响集中在上层20 - 30 m的水柱。
Both rainfall and wind have acoustic signatures that can be discerned at depths in the ocean well below the sea surface. We examine observations of rainfall and wind speed collected at a depth of 600 m in the Bay of Bengal from a specially modified Argo profiling float. In addition to the normal Argo sensors, the float carried a passive acoustic listener sensor package that monitored the spectrum of acoustic noise along the float trajectory at intervals of a few minutes and used a set of existing algorithms to estimate the wind speed and rainfall rate from these noise spectra. A comparison of the acoustically derived wind speed and rainfall estimates with analogous satellite‐derived data (rainfall from the Tropical Rainfall Measuring Mission and QwikScat winds) showed general agreement in both cases, although the float‐based measurements were representative of conditions a few kilometers around the float, whereas the remotely sensed observations were smoothed over much larger length scales. The strong monsoon signal in the Bay of Bengal is clearly present in the float‐based wind and rainfall data. The near‐surface salinity measured by the float varied because of both rainfall events and the proximity to strong coastal runoff from major rivers. The float profiles of temperature and salinity in the upper ocean, and the effects of wind and rainfall, were simulated in a version of the Price‐Weller‐Pinkel mixed‐layer model, which showed that the direct effects of most rainfall events are concentrated in the upper 20‐30 m of the water column.