Charge distribution estimation device, charge distribution estimation method, and program

Abstract

To provide a charge distribution estimation device, charge distribution estimation method and program, which enable charge distribution measurement in smaller regions within a thundercloud.SOLUTION: A charge distribution estimation device is provided, comprising a data acquisition unit 11 for acquiring an initial charge distribution within a thundercloud 51, a first computation unit 131 configured to divide a region of the thundercloud 51 into multiple division planes D1-DM to compute neutralizing charge caused by lightning discharge in each of the division planes D1-DM, and a second computation unit 132 configured to compute a charge distribution in each division plane on the basis of the initial charge distribution and the neutralizing charge.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a charge distribution estimation device, a charge distribution estimation method, and a program for estimating a charge distribution in a thundercloud. [Background technology]

[0002] As a technology for predicting the occurrence of lightning, Non-Patent Documents 1 and 2 disclose lightning nowcasting, which detects thunderclouds where lightning is about to strike. Lightning nowcasting discloses that it calculates the probability of lightning for each specified area based on the statistical relationship between past lightning data and current cloud radar information.

[0003] Non-Patent Document 3 discloses that the electric field distribution on the ground is measured using an electric field meter such as a field mill, and the charge distribution in a thundercloud is estimated based on this electric field distribution, thereby predicting the probability of lightning striking in a specified area on the ground.

[0004] Non-Patent Document 4 discloses the causes of lightning strikes and the types of damage caused by lightning strikes, such as direct lightning strikes, induced lightning strikes, and backflow lightning strikes. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Japan Meteorological Agency, Lightning Nowcast, Analysis and Prediction Technology, Japan Meteorological Agency, Analysis and Prediction Technology (jma.go.jp) [Non-patent document 2] Japan Meteorological Agency, Lightning Nowcast, Detection of Areas with Possible Lightning Strikes Japan Meteorological Agency, Detection of Thunderclouds with Imminent Lightning Strikes (jma.go.jp) [Non-patent document 3] Takahashi, T. "The Science of Lightning." University of Tokyo Press (2009). [Non-patent document 4] Showden Corporation, Lightning Occurrence and Types of Lightning Damage, Mechanism of Lightning Damage [Lightning Occurrence and Types of Lightning Strikes], Basic Knowledge, Lightning Damage Prevention, Showden Corporation (sdn.co.jp) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technologies disclosed in the above-mentioned Non-Patent Documents 1 and 2 estimate the area where lightning strikes will occur by incorporating data on past lightning strike locations over a wide area, such as an area of ​​several square kilometers, and the general shape of the thundercloud as variables, making it difficult to implement lightning protection measures in a small area of ​​just a few meters on the ground.

[0007] Furthermore, Non-Patent Document 3 describes measuring the charge distribution within a thundercloud to predict the occurrence of ground discharge, but does not disclose measuring the charge distribution in a narrow region of several meters within a thundercloud.

[0008] Similarly, Non-Patent Document 4 does not disclose measuring the charge distribution in a narrow area of ​​several meters within a thundercloud, which poses a problem that it is not possible to predict with high accuracy discharges to the ground in a narrow area of ​​several meters on the ground.

[0009] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a charge distribution estimation device, a charge distribution estimation method, and a program that are capable of measuring the charge distribution within a thundercloud in a narrower area. [Means for solving the problem]

[0010] A charge distribution estimation device according to one embodiment of the present disclosure includes a data acquisition unit that acquires an initial charge distribution within a thundercloud, a first calculation unit that divides the thundercloud region into a plurality of divided surfaces and calculates neutralized charges generated due to lightning discharges on each divided surface, and a second calculation unit that calculates the charge distribution on each divided surface based on the initial charge distribution and the neutralized charges.

[0011] In one embodiment of the charge distribution estimation method of the present disclosure, an acquisition unit acquires an initial charge distribution within a thundercloud, a first calculation unit divides the thundercloud region into a plurality of division planes, and calculates the neutralized charge generated due to lightning discharge at each division plane, and a second calculation unit calculates the charge distribution at each division plane based on the initial charge distribution and the neutralized charge.

[0012] One aspect of the present disclosure is a program for causing a computer to function as the charge distribution estimation device. [Effects of the Invention]

[0013] According to the present disclosure, it becomes possible to measure the charge distribution within a thundercloud in a narrower area. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram showing a thundercloud above the area where the charge distribution is to be measured. [Figure 2] FIG. 2 is a block diagram showing the configuration of the charge distribution estimation device according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram that shows a schematic view of a thundercloud region D when two division planes D1 and D2 are set. [Figure 4] FIG. 4 is an explanatory diagram showing predicted values ​​of the number of lightning strikes in the analysis domain. [Figure 5] FIG. 5 is a block diagram showing a hardware configuration of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing a thundercloud existing above an area (hereinafter referred to as "analysis area") where the charge distribution is to be measured. As shown in Fig. 1, the upper layer of the thundercloud 51 is positively charged (indicated by "+" in the figure), and the lower layer is negatively charged (indicated by "-" in the figure). As the lower layer of the thundercloud 51 is negatively charged, the ground 52 in the analysis area is positively charged.

[0016] When a lightning discharge 53 occurs between a thundercloud 51 and the ground 52, a portion of the charge on the thundercloud 51 is neutralized. In this embodiment, the charge distribution within a newly generated thundercloud 51 is calculated based on observation data from a weather radar. Furthermore, multiple division planes are set within the analysis domain, and the neutralized charge neutralized by the lightning discharge 53 on each division plane is calculated to estimate the charge distribution on each division plane. In other words, by dividing the analysis domain into smaller division planes (for example, areas of several meters) and obtaining the charge distribution on each division plane, it becomes possible to predict the occurrence of lightning strikes in smaller areas. Note that there may be cases where the upper layer of a thundercloud is negatively charged and the lower layer is positively charged. In this case, the ground 52 will be negatively charged.

[0017] 2 is a block diagram showing the configuration of the charge distribution estimation device 1 according to the embodiment. As shown in FIG. 2, the charge distribution estimation device 1 includes a data acquisition unit 11, a parameter acquisition unit 12, and a calculation unit 13.

[0018] The data acquisition unit 11 acquires thundercloud data from an external device such as a weather radar. The thundercloud data includes the charge distribution within the thundercloud. The weather radar observes thunderclouds that exist above the analysis area. The weather radar estimates the charge distribution within the thundercloud using a well-known estimation method based on various information such as the size, shape, direction, phase change, and fall mode of precipitation particles within the thundercloud. The data acquisition unit 11 acquires the charge distribution within the thundercloud estimated by the weather radar.

[0019] The data acquisition unit 11 is connected to a plurality of electric field meters 21 (for example, field mills) installed at a plurality of locations in the analysis region, and acquires the electric field distribution observed by each electric field meter 21.

[0020] The parameter acquisition unit 12 acquires various parameters used to estimate the charge distribution. Specifically, a plurality of rectangular regions (hereinafter referred to as "division planes") are set in an area above the analysis region (hereinafter referred to as "thundercloud region D"). The parameter acquisition unit 12 acquires the number of division planes and the two-dimensional coordinates of the analysis region.

[0021] Fig. 3 is an explanatory diagram that shows a schematic diagram of two divided planes D1 and D2 set within the thundercloud region D described above. In the example shown in Fig. 3, the number of divided planes is "2". Note that the number of divided planes is not limited to "2" and may be "3" or more. In Fig. 3, the up-down direction is defined as the x-axis, the left-right direction as the y-axis, and the direction perpendicular to the paper surface as the z-axis, which is the height direction.

[0022] As shown in FIG. 3, if the height from the ground is z, the coordinates of the four corners of the thundercloud region D are (x0, y0, z), (x1, y0, z), (x0, y2, z), and (x1, y2, z). The coordinates of the four corners of the divided surface D1 are (x0, y0, z), (x1, y0, z), (x0, y1, z), and (x1, y1, z). The coordinates of the four corners of the divided surface D2 are (x0, y1, z), (x1, y1, z), (x0, y2, z), and (x1, y2, z). The parameter acquisition unit 12 acquires each of the coordinates described above.

[0023] Furthermore, the parameter acquisition unit 12 acquires the coordinates (position information) of the electric field meter 21 installed on each divided surface.

[0024] The calculation unit 13 includes a first calculation unit 131 and a second calculation unit 132.

[0025] The first calculation unit 131 calculates the neutral charge on each of the divided surfaces D1 and D2. The procedure for calculating the neutral charge on each divided surface will be described below.

[0026] First, the symbols are defined as follows.

[0027] z: Altitude of thundercloud region D M: The number of division planes in the thundercloud region D (in the example shown in Figure 3, M = 2) Q1 to QM: Neutralizing charges within each division surface D1 to DM obtained by lightning discharge X1 to XN: coordinates of the electric field meters 21 installed at N points in the analysis area E1 to EN: electric fields observed by each electric field meter 21 Furthermore, the center of gravity of the neutral charge on each division surface is X i G (i=1,2,··,M), and the neutral charge on each division surface is the center of gravity X i G In other words, the neutralizing charges are concentrated at one point on each divided surface. Based on the above symbols, the following formula (1) is defined.

[0028]

number

[0029] In equation (1), the equation between the double vertical lines indicates the three-dimensional distance between the two numbers.

[0030] The neutralizing charges Q1 to QM on each of the divided surfaces D1, D2, . . . , DM are solutions that satisfy the above formula (1). That is, the first calculation unit 131 shown in FIG. 1 calculates the neutralizing charges on each divided surface that minimize the result of the above formula (1).

[0031] The second calculation unit 132 shown in Figure 1 calculates the charge distribution on each division surface based on the charge distribution (thundercloud data) within the thundercloud 51 acquired by the data acquisition unit 11 and the neutralized charge calculated by the first calculation unit 131.

[0032] Specifically, when the charge distribution in the thundercloud region D is α coulombs, the second calculation unit 132 divides this equally based on the number of divided surfaces and sets the initial charge distribution on each of the divided surfaces D1 to DM to (α / M) coulombs. When the neutralization charge on the divided surface D1 calculated by the first calculation unit 131 is β coulombs, the second calculation unit 132 estimates that the charge on the divided surface D1 is (α / M-β) coulombs from the difference between these. Note that the initial charge distribution may be set by weighting each divided surface instead of dividing the α coulombs equally based on the number of divided surfaces.

[0033] The second calculation unit 132 calculates the electric field distribution of each divided surface in the thundercloud 51 based on the charge distribution on each divided surface. If the electric field distribution exceeds a predetermined threshold, the second calculation unit 132 estimates that the probability of lightning strikes is increasing in the ground region of this divided surface D1.

[0034] Figure 4 is an explanatory diagram showing the predicted number of lightning strikes in the analysis area, where (a) shows the estimated charge distribution (P1 to Pn) on each divided surface, (b) shows the electric field distribution (F1 to Fn) on each divided surface, and (c) shows the predicted number of lightning strikes within the analysis area.

[0035] The second calculation unit 132 calculates the probability of lightning strikes on each divided surface based on the electric field distribution (F1 to Fn) shown in Fig. 4(b), and displays the number of lightning strikes within 10 minutes on a map, for example, as shown in Fig. 4(c). By looking at this display, the user can recognize the probability of lightning strikes occurring in a small area of ​​several meters.

[0036] As described above, the charge distribution estimation device 1 according to this embodiment includes a data acquisition unit 11 that acquires the initial charge distribution within the thundercloud 51, a first calculation unit 131 that divides the area of ​​the thundercloud 51 into a plurality of division planes D1 to DM and calculates the neutralized charge generated due to the lightning discharge on each division plane D1 to DM, and a second calculation unit 132 that calculates the charge distribution on each division plane based on the initial charge distribution and the neutralized charge.

[0037] Therefore, the probability of a lightning strike occurring can be calculated for each divided surface, which is an area smaller than the analysis area, making it possible to predict the occurrence of a lightning strike in a small area of ​​several meters.

[0038] In this embodiment, the charge distribution within the thundercloud 51, which is directly related to the occurrence of lightning strikes, is estimated for each divided surface, thereby improving the accuracy of lightning strike prediction. Also, since a microscopic quantity called charge is incorporated into the prediction formula (the above-mentioned formula (1)), it becomes possible to predict the occurrence of lightning strikes over a smaller area. Furthermore, since it is possible to predict the occurrence of lightning strikes within a certain period of time, it becomes possible to predict the occurrence of lightning strikes over a smaller area.

[0039] In this embodiment, the first calculation unit 131 calculates the neutralization charge based on the electric field distribution measured by the electric field meter 21 installed on the ground, making it possible to calculate the charge distribution on each divided surface with higher accuracy.

[0040] In this embodiment, the second calculation unit 132 calculates the charge distribution on each divided surface based on the position information (coordinates) of the electric field meter 21 in addition to the initial charge distribution and neutralization charge, making it possible to calculate the charge distribution on each divided surface with higher accuracy.

[0041] The second calculation unit 132 calculates the charge distribution on the assumption that the neutralized charges are concentrated at one point on the divided surface, and therefore it is possible to calculate the charge distribution on each divided surface with higher accuracy.

[0042] The electric charge distribution estimation apparatus 1 of the present embodiment described above can be, for example, a general-purpose computer system including a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906, as shown in Fig. 5. The memory 902 and the storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program loaded on the memory 902, thereby realizing each function of the electric charge distribution estimation apparatus 1.

[0043] The charge distribution estimation apparatus 1 may be implemented by one computer or by multiple computers. Furthermore, the charge distribution estimation apparatus 1 may be a virtual machine implemented on a computer.

[0044] The program for the electric charge distribution estimation device 1 can be stored in a computer-readable recording medium such as an HDD, an SSD, a USB (Universal Serial Bus) memory, a CD (Compact Disc), or a DVD (Digital Versatile Disc), or can be distributed via a network. The computer-readable recording medium is, for example, a non-transitory recording medium.

[0045] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0046] 1 Charge distribution estimation device 11 Data Acquisition Section 12 Parameter acquisition section 13 Arithmetic section 21 Electric field meter 51 Thundercloud 52 Ground 53 Lightning discharge 131 First Calculation Unit 132 Second Calculation Unit D Thundercloud area D1~DM split plane

Claims

1. a data acquisition unit for acquiring an initial charge distribution within a thundercloud; a first calculation unit that divides a thundercloud region into a plurality of divided planes and calculates a neutralizing charge generated due to lightning discharge on each divided plane; a second calculation unit that calculates a charge distribution on each divided surface based on the initial charge distribution and the neutralized charges; A charge distribution estimation device comprising:

2. The first calculation unit calculates the neutralization charge based on an electric field distribution measured by an electric field meter installed on the ground. The charge distribution estimation device according to claim 1 .

3. The second calculation unit calculates the charge distribution on each divided surface based on the initial charge distribution, the neutralized charge, and position information of the electric field meter. The charge distribution estimation device according to claim 2 .

4. The second calculation unit calculates the charge distribution by assuming that the neutralized charges are concentrated at one point on the division surface. The charge distribution estimation device according to any one of claims 1 to 3.

5. The acquisition unit acquires the initial charge distribution within the thundercloud, a first calculation unit dividing a thundercloud region into a plurality of divided planes and calculating a neutralizing charge generated due to a lightning discharge in each divided plane; A second calculation unit calculates the charge distribution on each divided surface based on the initial charge distribution and the neutralized charge. Charge distribution estimation method.

6. A program that causes a computer to function as the charge distribution estimation device according to claim 1.

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