...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nonlinear processes in geophysics >Non-Gaussian statistics in global atmospheric dynamics: a study with a 10 240-member ensemble Kalman filter using an intermediate atmospheric general circulation model
【24h】

Non-Gaussian statistics in global atmospheric dynamics: a study with a 10 240-member ensemble Kalman filter using an intermediate atmospheric general circulation model

机译：全球大气动态的非高斯统计：使用中间大气通用循环模型的10 240-成员合奏卡尔曼滤波器研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We previously performed local ensemble transform Kalman filter (LETKF) experiments with up to 10 240 ensemble members using an intermediate atmospheric general circulation model (AGCM). While the previous study focused on the impact of localization on the analysis accuracy, the present study focuses on the probability density functions (PDFs) represented by the 10 240-member ensemble. The 10 240-member ensemble can resolve the detailed structures of the PDFs and indicates that non-Gaussianity is caused in those PDFs by multimodality and outliers. The results show that the spatial patterns of the analysis errors are similar to those of non-Gaussianity. While the outliers appear randomly, large multimodality corresponds well with large analysis error, mainly in the tropical regions and storm track regions where highly nonlinear processes appear frequently. Therefore, we further investigate the life cycle of multimodal PDFs, and show that they are mainly generated by the on-off switch of convective parameterization in the tropical regions and by the instability associated with advection in the storm track regions. Sensitivity to the ensemble size suggests that approximately 1000 ensemble members are necessary in the intermediate AGCM-LETKF system to represent the detailed structures of non-Gaussian PDFs such as skewness and kurtosis; the higher-order non-Gaussian statistics are more vulnerable to the sampling errors due to a smaller ensemble size.
机译：之前，我们之前的整个集合变换了Kalman滤波器（LetkF）实验，使用中间大气普通循环模型（AGCM）具有多达10 240个集合构件。虽然之前的研究专注于定位对分析准确性的影响，但是本研究侧重于10 240-成员集合所示的概率密度函数（PDF）。 10 240成员合奏可以解决PDF的详细结构，并表示通过多模和异常值在这些PDF中引起非高斯度。结果表明，分析误差的空间模式类似于非高斯的空间模式。虽然异常值随机出现，但大的多模对应于大分析误差，主要是在热带地区和风暴轨道区域，其中经常出现高度非线性过程。因此，我们进一步研究了多模式PDF的生命周期，并表明它们主要由热带地区的对流参数化的开关切换和与风暴轨道区域的平流相关的不稳定性产生。对集合尺寸的敏感性表明，中间AGCM-Letkf系统中需要大约1000个集合构件，以表示非高斯PDF的详细结构，如偏斜和峰氏症;由于集成尺寸较小，更高阶的非高斯统计数据更容易受到采样误差。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号