Thundercloud detection system

Abstract

To provide a technique capable of easily predicting occurrence of lightning.SOLUTION: A thundercloud detection system 1 includes an electric field meter 10 for observing an electric field in the atmosphere, and a thundercloud detection device 20 for acquiring observation data of the electric field from the electric field meter and detecting thunderclouds on the basis of a fluctuation width of electric field intensity and a fluctuation period of the electric field intensity included in the observation data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thundercloud detection system. [Background technology]

[0002] One method for predicting lightning strikes that can cause damage to facilities and people is to detect electromagnetic waves associated with lightning strikes using multiple antennas and determine the location of the lightning strike from the direction of arrival and the difference in arrival time of the simultaneously observed electromagnetic waves (Non-Patent Document 1).Furthermore, there is a method for predicting areas that are likely to be hit by lightning using numerical calculations based on the determined lightning strike location (Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] "Lightning Observation and Lightning Strike Status," Franklin Japan Co., Ltd., [online], [Retrieved March 21, 2024]<URL: https: / / www.franklinjapan.jp / network / jldn / > [Non-patent document 2] "Reality and Challenges in Lightning Prediction and Control", Nippon Telegraph and Telephone Corporation, [online], [Retrieved January 24, 2024],<URL: https: / / www.rd.ntt / se / media / article / 0045.html> Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional methods require advance detection of lightning, making it impossible to predict new thunderclouds that may form in the early stages of a lightning event or during a forecast. Furthermore, because it is necessary to observe electromagnetic waves emitted from lightning at multiple points, the installation and operation of observation equipment is costly.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique that makes it possible to easily predict the occurrence of lightning. [Means for solving the problem]

[0006] A thundercloud detection system according to one embodiment of the present invention comprises an electric field meter that observes electric fields in the atmosphere, and a thundercloud detection device that acquires electric field observation data from the electric field meter and detects thunderclouds based on the fluctuation range and fluctuation period of the electric field strength contained in the observation data. [Effects of the Invention]

[0007] According to the present invention, a technique that can easily predict the occurrence of lightning can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a thundercloud detection system according to this embodiment. [Figure 2] FIG. 2 is a diagram showing the change in electric field intensity over time. [Figure 3] FIG. 3 is a diagram illustrating the operation of the thundercloud detection system. [Figure 4] FIG. 4 is a diagram showing the hardware configuration of the thundercloud detection device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0010] Thunderclouds are divided into three layers of positive charge, negative charge, and positive charge within cumulonimbus clouds, and before and after lightning strikes, they drop electrically charged raindrops (Takahashi, "The mechanism of charge generation in thunderclouds - the mystery of the reversal of the charge sign in hail," 2003 Fujiwara Prize commemorative lecture, Meteorological Society of Japan, "Tenki" 51, January 2004, pp. 7-15).

[0011] Therefore, in this disclosure, an electric field meter is installed in the immediate vicinity of the charged raindrops to detect the electric charge (electric field) contained in the charged raindrops falling from thunderclouds.

[0012] When raindrops carrying an electric charge fall directly under a thundercloud near an electric field meter, the fluctuation range of the detected electric field strength becomes larger, and the fluctuation period of the electric field strength (the time it takes for the electric field strength to cycle back to a certain point and return to its original strength) becomes shorter. On the other hand, normal raindrops do not produce such electric field fluctuations. Furthermore, the electric field fluctuations are significantly different from those caused by lightning strikes such as land-to-ground lightning and cloud-to-cloud discharge.

[0013] This disclosure detects thunderclouds based on such atmospheric electric field fluctuations. This makes it possible to detect thunderclouds before lightning strikes in limited areas or near buildings, etc., and to predict the occurrence of lightning. In addition, electric field meters are cheaper than electromagnetic wave observation antennas, and a single electric field meter can easily predict early lightning strikes.

[0014] FIG. 1 is a diagram showing the configuration of a thundercloud detection system according to this embodiment.

[0015] The thundercloud detection system 1 determines whether or not there is an electric charge in the raindrops based on the electric field fluctuation level (fluctuation range of electric field strength), the electric field fluctuation period (fluctuation period of electric field strength), and the electric field fluctuation duration.

[0016] The thundercloud detection system 1 includes an electric field meter 10 that observes electrostatic fields in the atmosphere, and a thundercloud detection device 20 that detects thunderclouds based on electric field fluctuations in the atmosphere contained in the electrostatic field observation data.

[0017] The electric field meter 10 includes an antenna 11 and an observation unit 12. The electric field meter 10 is installed at a desired outdoor location and observes changes in the atmospheric electric field. The electric field meter 10 is, for example, a field mill.

[0018] The thundercloud detection device 20 includes a division unit 21, a first determination unit 22, a first setting unit 23, a second determination unit 24, a second setting unit 25, a third determination unit 26, and an output unit 27. The thundercloud detection device 20 is, for example, a computer connected to the electric field meter 10 so as to be able to communicate with it.

[0019] The dividing unit 21 has a function of acquiring observation data of the atmospheric electric field from the electric field meter 10 and dividing the observation data at regular time intervals.

[0020] The first determination unit 22 has a function of acquiring the fluctuation range of the electric field strength from each piece of divided observation data, and determining whether or not the fluctuation range of the electric field strength is greater than the fluctuation range threshold of the electric field strength.

[0021] For example, the first determining unit 22 acquires the amplitude value of the field strength from each piece of divided observation data, and selects only the observation data whose amplitude value of the field strength is greater than the amplitude value threshold of the field strength.

[0022] The first setting unit 23 has a function of setting a fluctuation width threshold of the electric field strength (for example, an amplitude value threshold of the electric field strength).

[0023] The second determination unit 24 has a function of acquiring the fluctuation period of the electric field strength from each piece of divided observation data, and determining whether or not the fluctuation period of the electric field strength is shorter than a fluctuation period threshold of the electric field strength.

[0024] For example, the second determination unit 24 acquires the fluctuation period of the electric field strength from each piece of observation data selected by the first determination unit 22, and selects only observation data whose fluctuation period of the electric field strength is shorter than the fluctuation period threshold of the electric field strength.

[0025] The second setting unit 25 has a function of setting a fluctuation cycle threshold of the electric field strength.

[0026] The third judgment unit 26 has a function of judging whether or not an electric field fluctuation in which the fluctuation range of the electric field strength is greater than the electric field strength fluctuation range threshold and the fluctuation period of the electric field strength is shorter than the electric field strength fluctuation period threshold continues for a certain period of time.

[0027] The third determination unit 26 has a function of determining that there is a thundercloud if the electric field fluctuation continues for a certain period of time or more, and determining that there is no thundercloud if the electric field fluctuation does not continue for a certain period of time or more.

[0028] For example, the third judgment unit 26 adds up all the times of each observation data selected by the second judgment unit 24, and if the total time after addition is equal to or longer than a certain time, it judges that a cloud containing an electric charge (thundercloud) is approaching the electric field meter 10, is directly above the electric field meter 10, or has passed directly above the electric field meter 10.

[0029] The output unit 27 has a function of issuing an alert indicating that there is a high possibility of lightning striking above the electric field meter 10 when the third determination unit 26 determines that there is a thundercloud.

[0030] Figure 2 shows the change in electric field strength over time. Figure 2(a) shows the electric field strength when observing charged raindrops, and Figure 2(b) shows the electric field strength when observing lightning strikes such as land-to-ground lightning and cloud-to-cloud discharges.

[0031] Comparing Figure 2(a) with Figure 2(b), we can see that the period of fluctuations in electric field strength due to charged raindrops is shorter than the electric field strength during lightning. A similar trend is also seen when comparing with normal raindrops and clear skies. Thunderclouds are detected based on these atmospheric electric field fluctuations.

[0032] FIG. 3 is a diagram illustrating the operation of the thundercloud detection system.

[0033] Step S1; The electric field meter 10 observes the change in the atmospheric electric field for 10 minutes.

[0034] Step S2; The thundercloud detection device 20 acquires observation data of the atmospheric electric field from the electric field meter 10, and divides the observation data into two-minute intervals.

[0035] Step S3; The thundercloud detection device 20 determines whether the amplitude value of the electric field strength is greater than 10 times that of a clear day for each of the multiple observation data after division, and selects only the observation data that meets this criteria from the multiple observation data. This "10 times" is a threshold determined in advance based on the difference in electric field strength level (V / m) between a thunderstorm day and a clear day measured in advance, etc. If there is no observation data with an amplitude value of the electric field strength greater than 10 times that of a clear day, the process returns to step S1.

[0036] Step S4; The thundercloud detection device 20 determines whether the fluctuation period of the electric field strength is shorter than 1 / 10 of that on a clear day for the selected observation data, and selects only the observation data that meets this criteria. This "1 / 10" is a threshold value determined in advance based on the fluctuation period of the electric field strength on a clear day that has been measured in advance.

[0037] Step S5; The thundercloud detection device 20 determines whether or not the amplitude value of the electric field strength is greater than 10 times that of a sunny day and the electric field strength fluctuation period is shorter than 1 / 10 times that of a sunny day, and the electric field fluctuation period continues for one minute or more, for the multiple observation data selected in step S4.

[0038] Step S6; The thundercloud detection device 20 determines that a thundercloud has passed directly above the electric field meter 10 if the electric field fluctuation continues for one minute or more.

[0039] Step S7; The thundercloud detection device 20 issues an alert indicating that there is a high possibility of lightning striking above the electric field meter 10.

[0040] Step S8; If it is determined in step S4 that there is no observation data with an electric field strength fluctuation period shorter than 1 / 10 of that on a sunny day, and if it is determined in step S5 that the amplitude value of the electric field strength is greater than 10 times that on a sunny day and the electric field fluctuation with an electric field strength fluctuation period shorter than 1 / 10 of that on a sunny day has not continued for one minute or more, the observed electric field fluctuation is determined to be a fluctuation caused by lightning.

[0041] According to this embodiment, the thundercloud detection system 1 comprises an electric field meter 10 that observes the electric field in the atmosphere, and a thundercloud detection device 20 that acquires electric field observation data from the electric field meter 10 and detects thunderclouds based on the fluctuation range and fluctuation period of the electric field strength contained in the observation data, thereby providing a technology that can easily predict the occurrence of lightning.

[0042] It will also be possible to detect thunderclouds before lightning strikes in limited areas or near buildings, etc., making it possible to predict the occurrence of lightning. Electric field meters are cheaper than electromagnetic wave observation antennas, and a single electric field meter can easily predict early lightning strikes.

[0043] The present disclosure is not limited to the above embodiment. The present disclosure can be modified in many ways within the scope of the gist of the present disclosure. For example, the order of steps S4 and S5 may be reversed. Steps S2 and S5 may not be performed. The specific values ​​mentioned above (e.g., 10 minutes) are examples.

[0044] The thundercloud detection device 20 of the present embodiment described above can be realized, for example, by using a general-purpose computer system including a CPU 901, a memory 902, a storage 903, a communication device 904, an input device 905, and an output device 906, as shown in Fig. 4. The memory 902 and the storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing each function of the thundercloud detection device 20.

[0045] The thundercloud detection device 20 may be implemented by one computer, or by multiple computers, or may be a virtual machine implemented on a computer.

[0046] The program for the thundercloud detection device 20 can be stored in a computer-readable recording medium such as a HDD, SSD, USB memory, CD, or DVD. The computer-readable recording medium is, for example, a non-transitory recording medium. The program for the thundercloud detection device 20 can also be distributed via a communication network. [Explanation of symbols]

[0047] 1. Thundercloud detection system 10 Electric field meter 11 Antenna 12 Observation Section 20 Thundercloud detection device 21 Division 22 First Judgment Section 23 First Setting Section 24 Second Judgment Section 25 Second Setting Section 26 Third Judgment Section 27 Output section 901 CPU 902 memory 903 Storage 904 Communication equipment 905 Input Device 906 Output Device

Claims

1. an electric field meter for observing the electric field in the atmosphere; a thundercloud detection device that acquires electric field observation data from the electric field meter and detects thunderclouds based on the fluctuation width and fluctuation period of the electric field strength included in the observation data; A thundercloud detection system comprising:

2. The thundercloud detection device The thundercloud detection system according to claim 1 , wherein the system determines that a thundercloud is present when the fluctuation range of the electric field strength is greater than the electric field strength fluctuation range threshold and the fluctuation period of the electric field strength is shorter than the electric field strength fluctuation period threshold.

3. The thundercloud detection device The thundercloud detection system of claim 1, wherein from among the multiple observation data obtained by dividing the observation data on a time axis, only observation data in which the fluctuation range of the electric field strength is greater than the electric field strength fluctuation range threshold and the fluctuation period of the electric field strength is shorter than the electric field strength fluctuation period threshold is selected.

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