龚建东,张林,王金成. 2020. 背景误差水平相关结构对四维变分资料同化的影响研究[J]. 气象学报, (0):-, doi:10.11676/qxxb2020.062
背景误差水平相关结构对四维变分资料同化的影响研究
The impact study of background error horizontal correlation structure on 4D-Var
投稿时间:2020-02-03  修订日期:2020-06-13
DOI:10.11676/qxxb2020.062
中文关键词:  GRAPES四维变分同化,背景误差水平相关,谱空间方差融合,数值试验
英文关键词:GRAPES 4D-Var,background error horizontal correlation, Spectral variance merge,numerical experiment
基金项目:
作者单位E-mail
龚建东 国家气象中心/数值预报中心 gongjid 
张林 国家气象中心/中国气象局 lzhang@cma.gov.cn 
王金成 国家气象中心/中国气象局 wangjch@cma.gov.cn 
摘要点击次数: 63
全文下载次数: 64
中文摘要:
      [目的]本文考察GRAPES全球4D-Var的分析增量在谱空间的时间演变特征,分析当同化时间窗起始时刻与终止时刻背景误差水平相关特征明显不一致时,对分析与预报造成的影响。[资料和方法]对GRAPES全球4D-Var的背景误差水平相关采用二阶自回归模型SOAR、集合资料同化生成扰动样本估计的水平相关模型、以及基于这两者的背景误差谱空间融合模型进行比较。[结果]结果表明SOAR模型的分析增量在20波以上的天气尺度波动的分析信息明显不足,而将集合资料同化样本所计算的水平相关的功率谱方差与SOAR功率谱方差进行融合,水平相关特征呈现出多尺度水平相关的特点,可以更好的吸纳观测信息,显著改善北半球形势场、温度与风场预报效果,南半球也有改善,对赤道地区的影响中性。[结论]表明本文发展的融合水平相关方案具有合理性和实用性。
英文摘要:
      The time evolution characteristics of the GRAPES global 4D-Var analysis increment in the spectral space is investigated in the paper,and the impact on the analysis and forecast is also analyzed when the background error horizontal correlation characteristics at the beginning and end of the data assimilation time window are obviously different. Three types of horizontal correlation model are compared; they are the second-order autoregressive model (SOAR), the statistical model from the samples generated by ensemble of data assimilation (EDA), and the blending results of SOAR and EDA. The results show that for SOAR model the information of synoptic scale in the analysis increment is obviously under-estimated. For the horizontal correlation power spectrum calculated by blending of SOAR and EDA, the results show a multi-scale horizontal correlation characteristics, which can better absorb the observation information and significantly improve the geopotential height and temperature in the northern hemisphere. The wind forecast is also improved in the southern hemisphere, and with a neutral impact in the tropical region. This shows that the merging horizontal correlation scheme developed in this paper is reasonable and practical.
查看全文   查看/发表评论  下载PDF阅读器
分享按钮