A Perturbation Method Based on Adaptive Sensitive Factor

Abstract

The invention relates to a perturbation method based on self-adaptive sensitive factors. The perturbation method comprises following steps of: (I) downloading recent 10 years of NCEP reanalysis data as sample data and respectively calculating obtained index information of each grid point of files at each time; (II) classifying meteorological disasters according to yearbooks of meteorological disasters in recent 10 years and saving corresponding index information to a database; (III) counting according to weather types: respectively giving value domains corresponding to information of all indexes in samples as the sample range used for determining possibly-occurring disastrous weathers in this kind; (IV) comparing anomalous percentage of precipitation of information on all indexes according to weather types and using the most significant variable of deviation average as a sensitive disturbance variable in a corresponding weather type; and (V) achieving diagnostic quantities for disturbance of information of all indexes in an initial field. The perturbation method based on self-adaptive sensitive factors has following beneficial effects: information of different criterions can be synthesized; the type of severe convection weathers in an overlap area for the applicable scopes of different criterions can be founded; and based on the above type, the most proper disturbance variable can be automatically and objectively selected.

Description

technical field [0001] The invention relates to the field of weather forecasting, in particular to a disturbance method based on an adaptive sensitive factor. Background technique [0002] Because the evolution of the initial error over time is significantly different in baroclinic instability and convective instability, the initial disturbance constructed by the medium-term ensemble disturbance method cannot grow rapidly in the convective system, that is, the initial disturbance structure is not consistent with the development of the storm system. In turn, the dispersion of ensemble members is lower than a reasonable level (Migliorini et al., 2011); on the other hand, the incompatibility between the initial disturbance of the storm scale and the scale of the side boundary disturbance will also limit the initial disturbance and ensemble dispersion degree of growth. Multiphysics processes (Berner, et al., 2011; Johnson et al., 2012) and multi-model (Park et al. The precipit...

AI Technical Summary

Problems solved by technology

[0002] Because the evolution of the initial error over time is significantly different in baroclinic instability and convective instability, the initial disturbance constructed by the medium-term ensemble disturbance method cannot grow rapidly in the convective system, that is, the initial disturbance structure is not consistent with the development of the storm system. In turn, the dispersion of ensemble members is lower than a reasonable level (Migliorini et al., 2011); on the other hand, the incompatibility between the initial disturbance of the storm scale and the scale of the side boundary disturbance will also limit the initial disturbance and ensemble dispersion degree of growth

Multiphysics processes (Berner, et al., 2011; Johnson et al., 2012) and multi-model (Park et al. The precipitation forecast variable and the threshold condition judgment of the microphysical process are different, which have a significant impact on the forecast of precipitation intensity and fall area (Chen Jing et al., 2005). For different types of storm systems that occur in real time, fixed variable Combinatorial selection of different modes of microphysics schemes is blind

Recently, some scholars have applied random physical perturbation method to large-scale, medium-scale and storm-scale models (Berner et al. Only random perturbation of physical parameters does not take into account the energy conservation conditions in the model physics scheme, which is the main reason why the SPPT scheme adopted by ECMWF is limited to the middle and upper atmosphere (in the boundary layer, SPPT without energy conservation will lead to collapse), the solution of this problem will help to further improve the forecast level of storm-scale ensemble forecast

[0003] On the other hand, the wind field and temperature field of the purely random disturbance mode can also change the values ​​of vertical wind shear, convective effective potential energy, helicity, Sabour index, and Jefferson index, but this change is very random, there is no Too much physical significance, and the magnitude of the disturbance is completely uncontrollable

Images