Method for assimilating cloud-to-ground lightning data through physical initialization

An initialization and data technology, applied in the direction of electrical digital data processing, special data processing applications, weather condition prediction, etc., to achieve good applicability, improve the effect, and improve the effect of forecast echo

CN103837911AActive Publication Date: 2014-06-04LANZHOU UNIVERSITY
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2014-06-04

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Abstract

The invention relates to a method for assimilating cloud-to-ground lightning data through physical initialization. The method comprises the following steps that (1), three-dimensional agent radar echoes converted through the lightning data are screened in the vertical direction to obtain the maximum echo reflectivity factor Ze; (2), precipitation intensity RR'obs is obtained according to a formula, and the precipitation intensity is converted into the precipitation flux mode RRobs; (3), the cloud top height is set to be the top height of the three-dimensional agent radar echoes, cloud bottom height is approximately substituted by the isentropic condensation level of a background field; (4), vertical ascending velocity in a cloud is expressed; (5), when the precipitation intensity RR'obs is smaller than the area of 0.1, the vertical velocity is kept consistent with that of the background, specific humidity and the cloud water content are not changed, the cloud water content is set to be zero, maximum relative humidity cannot exceed 80 percent, and when the precipitation intensity RR'obs is larger the area of 0.1, the specific humidity and the cloud water content are adjusted. The method can effectively improve nowcasting precision of a mode on a severe convection system.
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Description

technical field

[0001] The invention relates to a processing method of meteorological data, in particular to a method of using physical initialization to assimilate ground lightning data. Background technique

[0002] Lightning, as a relatively common discharge phenomenon in the atmosphere, can provide detailed information on the time, location, quantity, polarity and intensity of discharges generated by convective clouds, and is less affected by terrain. It is higher than that of weather radar, which makes lightning data have certain advantages in the study of severe convective weather. If the lightning data is used in the initialization process of refined weather forecast and further improves the accuracy of convective activity information in the initial field of the model, it is expected to play an important role in improving the accuracy of short-term forecast of severe convective weather. The research on the assimilation of lightning location network data has just star...

Examples

Embodiment Construction

[0064] A method of using physical initialization to assimilate lightning data, comprising the following steps:

[0065] (1) Screen the 3D proxy radar echoes converted from lightning data in the vertical direction to obtain the maximum echo reflectivity factor , its unit is mm 6 / m 3 ;

[0066] ⑵ According to get precipitation intensity , and then according to Will Converted to the form of precipitation flux ; Among them: 1.4 and 300 are empirical coefficients; The unit is mm / h; The unit is kg / (m 2 s);

[0067] (3) Let the cloud top height be the top height of the three-dimensional radar proxy echo, and the cloud base height is approximately replaced by the uplift condensation height of the background field:

[0068]

[0069] in: and are the temperature and dew point temperature at a height of 2m, respectively; Z cb is the cloud base height;

[0070] (4) The vertical rising speed in the cloud is expressed as:

[0071]

[0072] in: is the verti...