Wavelet Analysis of Properties of Marine Boundary Layer Mesoscale Cells Observed From AMSR‐E
Wavelet Analysis of Properties of Marine Boundary Layer Mesoscale Cells Observed From AMSR‐E
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DOI：
10.1029/2021jd034666
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发表时间：
2021-06
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影响因子：
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通讯作者：
Xiaoli Zhou;C. Bretherton;R. Eastman;I. McCoy;R. Wood
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文献类型：
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作者：
Xiaoli Zhou;C. Bretherton;R. Eastman;I. McCoy;R. Wood
海洋边界层云倾向于组织成封闭或开放的中尺度细胞对流（MCC）。在这里，二维小波分析首次应用于被动微波反演的云水路径（CWP），水汽路径（WVP）和降雨率（RR）从高级微波扫描辐射计地球观测系统在2008年东北和东南太平洋，以及东南大西洋副热带层积云积云过渡区。在160 × 160 km 2的分析框中，CWP、WVP和RR之间的（协）变率被划分为四个中尺度波长倍频程（20、40、80和160 km）。单元格尺度被标识为峰值CWP方差的波长。结合细胞类型的机器学习分类，这使得各种尺度的开放和封闭MCC的统计特征及其与WVP，RR和潜在环境控制因素的关系能够在非常大的案例集中进行分析。结果表明，小区波长一般为40-80 km。细胞尺度CWP扰动是WVP和RR扰动的良好预测因子。对于大于20 km的电池，电池规模对测试的环境控制因素没有明显的依赖性，这表明电池规模可能更多地取决于其历史演变而不是当前的环境条件。
Marine boundary layer clouds tend to organize into closed or open mesoscale cellular convection (MCC). Here, two‐dimensional wavelet analysis is applied for the first time to passive microwave retrievals of cloud water path (CWP), water vapor path (WVP), and rain rate (RR) from Advanced Microwave Scanning Radiometer for Earth Observing System in 2008 over the Northeast and Southeast Pacific, and the Southeast Atlantic subtropical stratocumulus to cumulus transition regions. The (co‐)variability between CWP, WVP, and RR in 160 × 160 km2 analysis boxes is partitioned between four mesoscale wavelength octaves (20, 40, 80, and 160 km). The cell scale is identified as the wavelength of the peak CWP variance. Together with a machine‐learning classification of cell type, this allows the statistical characteristics of open and closed MCC of various scales, and its relation to WVP, RR, and potential environmental controlling factors to be analyzed across a very large set of cases. The results show that the cell wavelength is most commonly 40–80 km. Cell‐scale CWP perturbations are good predictors of the WVP and RR perturbations. For cells larger than 20 km, there is no obvious dependence of cell scale on the environmental controlling factors tested, suggesting that the cell scale may depend more on its historical evolution than the current environmental conditions.