Observation of the surface mixed layer and its modeling

我们开发了一种新的微结构仪器，可以同时观察物理和生物参数。该仪器配备了标准的湍流传感器和温度梯度，以及用于测量原位叶绿素和浊度变化的生物光学传感器。用该剖面仪和声波多普勒测速仪在一个流量罐中进行了同时测量，两种仪器的数据吻合良好。在超过15年的波数空间中，两种仪器计算的湍流谱与柯尔莫哥洛夫惯性子范围假设一致。利用剖面仪进行的现场测试数据表明，在对剪切探针的空间平均进行修正后，原位湍流谱测量结果与经验Nasmyth谱一致。耗散率低至5 × 10^<-10> W kg^<-1>。研制并校准了一种新型高分辨率生物光学传感器。该探针使我们能够进行高分辨率的测量……更多的原位叶绿素和浊度元素。在多个室内实验中对探头的灵敏度和空间分辨率进行了测试。测试数据分析表明，该探针能够分辨小至0.02 m的叶绿素空间分布。对现场试验记录的叶绿素和浊度信号的光谱特征分析证实了实验室的结果。根据先前进行的现场实验数据，我们从安装在研究潜艇上的翼型剪切探头和热敏电阻获得的垂直湍流速度和瞬时热通量信号中确定了开尔文-亥姆霍兹波浪。垂直湍流速度表明，波浪的水平尺度约为3.5 m。垂直湍流速度分量的谱斜率接近于-2，表明气流是二维的。我们发现观测到的波浪长度尺度与基于类似条件的直接数值模拟计算的波浪长度尺度之间有显著的一致性。为了将新的野外测量结果与数值模型相结合，我们利用2.5水平的Mello-Yamada闭合模型开发了浮游植物生产的随机游动模拟模型。我们将这种新方法与简单的Ekman层模型进行了比较。我们报告了Mello-Yamada模型中的快速深度对随机行走轨迹有显著影响，然而，模拟结束时的总产量显示出相似的结果。少

We have developed a new microstructure instrument to observe both physical and biological parameters simultaneously. The instrument is equipped with standard turbulence sensors and temperature gradient, as well as bio-optical sensors for measuring in situ chlorophyll and turbidity variations. Simultaneous measurements with this profiler and an acoustic Doppler velocimeter were carried our in a flow tank, and data from both instrument agreed well. Turbulence spectra computed from both instruments agreed with the Kolmogorov inertia subrange hypothesis over more than 1.5 decades in wavenumber space. Data from field tests conducted with the profiler showed that turbulence spectra measure in situ agreed with the empirical Nasmyth spectrum when corrections were made for the shear probe's spatial averaging. Dissipation rates as low as 5x10^<-10> W kg^<-1> were resolved.A new high-resolution bio-optical sensor is developed and calibrated. The probe enables us to perform high-resolution measure … More ments of in-situ chlorophyll and turbidity. The sensitivity and the spatial resolution of the probe are tested in several laboratory experiments. Analysis of the test data shows that this probe is capable of resolving spatial distributions of chlorophyll as small as 0.02 m. Analysis of the spectral characteristics of chlorophyll and turbidity signals recorded in field tests corroborate the laboratory results.From a previously conducted field experimental data we identified a Kelvin-Helmholtz billow from vertical turbulence velocity and instantaneous heat flux signals obtained from airfoil shear probes and thermistors mounted on a research submarine. The vertical turbulence velocity indicates that the horizontal scale of the billow was about 3.5 m. The spectral slope of the vertical turbulence velocity component is close to -2, revealing the flow is two-dimensional. We show a remarkable agreement between the length scales of the observed billow and those computed from direct numerical simulations based on similar conditions.In order to combine the new field measurements with numerical models, we are developing a random walk simulation model for phytoplankton production making use of 2.5 level Mello-Yamada closure model. We have compared this new approach with a simple Ekman layer model. We report a rapid deeping revealed in Mello-Yamada model makes a significant difference in the random walk trajectories, however, the total productions at the end of the simulation show similar results. Less