Adjoint-based Sensitivity Analysis of a Mesoscale Low on the Mei-yu Front and Its Implications for Adaptive Observation

• Published in: Advances in atmospheric sciences Vol. 24; no. 3; pp. 435 - 448
• Main Author: 钟科 董佩明 赵思雄 蔡其发 兰伟仁
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.05.2007
• Subjects: Atmospheric sciences; Sensitivity analysis; Simulation; Studies; Troposphere; 中尺度低压; 梅雨锋面; 联合敏感性分析; 自适应观测
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-007-0435-9

An adjoint sensitivity analysis of one mesoscale low on the mei-yu Front is presented in this paper. The sensitivity gradient of simulation error dry energy with respect to initial analysis is calculated. And after verifying the ability of a tangent linear and adjoint model to describe small perturbations in the nonlinear model, the sensitivity gradient analysis is implemented in detail. The sensitivity gradient with respect to different physical fields are not uniform in intensity, simulation error is most sensitive to the vapor mixed ratio. The localization and consistency are obvious characters of horizontal distribution of the sensitivity gradient, which is useful for the practical implementation of adaptive observation. The sensitivity region tilts to the northwest with height increasing; the singular vector calculation proves that this tilting characterizes a quick-growing structure, which denotes that using the leading singular vectors to decide the adaptive observation region is proper. When connected with simulation of a mesoscale low on the mei-yu Front, the sensitivity gradient has the following physical characters： the obvious sensitive region is mesoscale, concentrated in the middle-upper troposphere, and locates around the key system; and the sensitivity gradient of different physical fields correlates dynamically.