JPH07110379A - Thundercloud observation system - Google Patents

Abstract

PURPOSE:To provide a thundercloud observation system capable of accurately detecting thundercloud regardless of seasons and judging the probability of thunder occurrence. CONSTITUTION:Each echo intensity in echo intensity information is converted into moisture amount in a moisture amount converter part 1. After transforming to rectangular coordinate in a CAPPI (constant altitude plan position indicator) conversion part 2, integration processing in the vertical direction is done in a VIL (vertical direction integral moisture amount) calculation part 3 and the amount is compared with a thundercloud judgment reference level in an integral moisture amount comparator 4. When an integral amount over the thunder judgment reference level is detected, it is judged to be thundercloud. On the other hand, echo top altitude over a reference value of echo intensity in the echo intensity information is obtained in an echo top altitude calculation part 6 and it is converted into echo top temperature based on aerological information in the echo top altitude calculation part 6 to compare it with a freezing judgment reference value in an echo top temperature comparison part 8. When the echo top temperature is detected to be below the freezing judgment reference value, a high probability of thunder occurrence is judged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates mainly to a thundercloud observation system for determining a thundercloud based on radar echo information from a weather radar and determining the possibility of a lightning strike.

[0002]

2. Description of the Related Art As is well known, the growth of thunderclouds is roughly classified into a developmental period, a maturation period and a decline period. FIG. 3 shows the state of the growth process. In FIG. 3, the horizontal axis represents elapsed time, the vertical axis represents altitude, and the numbers in the figure represent radar echo intensity [dBz]. Echo intensity is proportional to water content.

For some reason, if the warm atmosphere (warm air) near the surface of the earth becomes a state (unstable state) where the cold atmosphere (cold air) is located above the ground surface, the warm air near the surface of the earth is light and tries to rise. Since the cold air is heavy, it tries to descend and convection occurs. At this time, if the rising airflow contains water, the water moves to a low temperature region in the sky to be condensed into water or ice crystals, and a cloud is generated.

When the upflow is particularly strong, the water content is high and the cloud develops rapidly. In such cases, the rate of thunderclouds is high. In this way, the period in which the updraft is predominant is positioned as the developmental period.

With the passage of time, the water above becomes dense and gradually forms nuclei, and the updraft becomes weaker in the maturation stage. When the top of the nucleus reaches the freezing height, ice particles are formed.
The particles become charged due to collisions, etc., and the charges are gradually accumulated. When electric charges are accumulated to some extent, a discharge phenomenon occurs and a lightning strike occurs.

When the ascending air current further weakens, it enters a declining period and turns into a descending air flow, and the phenomenon of convergence occurs in the upper part and the phenomenon of divergence occurs in the lower part. Then, the water region drops and the charged nucleus approaches the surface of the earth. As a result, lightning strikes are concentrated due to the potential difference between the nucleus and the surface. The thundercloud disappears when the moisture region almost falls to the ground surface.

In a conventional thundercloud observation system that detects such a thundercloud and predicts lightning, a thundercloud is based on the idea that "the radar echo of a thundercloud is higher and stronger than the echo of an ordinary rain cloud." Is determined. That is,
For example, the discrimination standard as shown in the following table is created using only the information on the echo intensity and the echo altitude. The difference between the methods of distinguishing between thunderclouds in summer and thunderclouds in winter is that the judgment values are different and the basic judgment conditions and their combinations are the same.

[0008]

[Table 1]

However, in the conventional system, the thundercloud in summer develops much higher than the ordinary rain cloud, so that it is relatively easy to distinguish and the detection rate is high, but the thundercloud in winter especially on the Sea of Japan side has a high altitude. Since it was not too high, it was difficult to distinguish it from the surrounding clouds, and the detection rate was low. In addition, even in summer thundercloud discrimination, there were many false detections because the discrimination criterion did not capture the mechanism of thundercloud generation and ups and downs.

[0010]

As described above, in the conventional thundercloud observation system, since the thundercloud is discriminated using only the information of the echo intensity and the echo altitude, there are many false detections, especially in the winter thundercloud. The discrimination accuracy was very low.

The present invention has been made in order to solve the above problems, and is capable of accurately detecting a thundercloud regardless of the season and determining the degree of lightning strike in accordance with the mechanism of thundercloud generation and rise and fall. The purpose is to provide a thundercloud observation system capable of

[0012]

To achieve the above object, a first thundercloud observation system according to the present invention inputs polar echo echo intensity information as radar information, and uses the echo intensity of each unit mesh as the moisture content. And a coordinate system conversion means for converting the water content information of the polar coordinate system obtained by this means into an orthogonal coordinate system, and a water content conversion means for converting it into a rectangular coordinate system. An integration processing means for performing integration processing in the vertical direction on the water content information in the Cartesian coordinate system, an integrated water content comparison means for comparing the integrated water content by this means with a thundercloud judgment reference value, and an echo intensity as a reference from the echo intensity information. Input the echo top height calculation means for obtaining the echo top height above the level and high-level meteorological information indicating the relationship between the altitude and temperature, and convert the echo top height to the echo top temperature from this information. Based on the comparison result of the echo top temperature conversion means, the echo top temperature comparison means for comparing the echo top temperature obtained by this means with the freezing determination reference value, the integrated moisture content comparison means and the echo top temperature comparison means. And a determination means for determining the possibility of lightning as well as determining that it is a thundercloud, and the determination means is the integrated moisture content comparison means for integrating the moisture content equal to or greater than the thundercloud determination reference value. When it is detected, it is determined that it is a thundercloud, and when it is detected that the echo top temperature is below the freezing determination reference value by the echo top temperature comparison means, it is determined that there is a high possibility of lightning. It is characterized by having done.

A second thundercloud observation system according to the present invention includes a convection zone detecting means for receiving Doppler radar information to detect a convection zone and its altitude, and a thundercloud based on altitude information of the convection zone detected by this means. Thundercloud ups and downs determining means for determining ups and downs, the thundercloud ups and downs determining means compares the altitude of the convection zone detected by the convection area detecting means with a thundercloud discrimination reference altitude, and based on the comparison result. It is characterized in that it determines whether the thundercloud is in the developing period or the declining period.

A third thundercloud observation system according to the present invention is a vertical direct current detecting means for receiving Doppler radar information to detect an upflow and a downflow, and a thundercloud for judging the ups and downs of the thundercloud based on the detection result of this means. A thundercloud ups and downs determination means, the thundercloud ups and downs determination means determines that the thundercloud is in a developmental period when an upflow is detected by the vertical direct current detection means, and a thundercloud during a declined period when a downflow is detected. It is characterized in that it is determined that there is.

A fourth thundercloud observation system according to the present invention receives a Doppler radar information to detect an upflow and a downflow, and a vertical direct current detecting means to receive the Doppler radar information to detect a convection zone and its altitude. A convection zone detecting means, and a thundercloud ups and downs determining means for determining ups and downs of a thundercloud based on the detection results of the vertical direct current detecting means and the convection zone detecting means, wherein the thundercloud ups and downs determining means is the vertical direct current detecting means. When an updraft is detected in, the thundercloud is judged to be in the developing period, when a downdraft is detected, it is judged that the thundercloud is in the declining period, and when vertical flow is not detected by this means, the convection area is detected. It is characterized in that the altitude of the convection area detected by the means is compared with the reference altitude of the thundercloud, and whether the thundercloud is in the developing period or the declining period is determined based on the comparison result.

[0016]

[Operation] In the first thundercloud observation system, the echo intensity of each unit mesh of echo intensity information is converted into the amount of water and converted into the Cartesian coordinate system, and then the vertical integration process is performed to compare with the thundercloud judgment reference value. Then, when the accumulated amount of water equal to or greater than the thundercloud determination reference value is detected, it is determined to be a thundercloud based on the condition that "the amount of water in a thundercloud is higher than that of an ordinary rain cloud." On the other hand, the echo apex height of the echo intensity of the echo intensity information is higher than the reference level, converted to the echo apex temperature based on the high-level meteorological information, and compared with the ice determination reference value, and the echo apex temperature is below the ice determination reference value. When it is detected that "the lightning requires ice particles."
It is determined that there is a high probability of a lightning strike based on the above condition.

In the second thundercloud observation system, the convective zone and its altitude are detected from the Doppler radar information, and from the result of comparison between the convective zone detected altitude and the thundercloud discrimination reference altitude, "at the time of thundercloud development Converge and diverge at higher levels. ”
When the condition is satisfied, it is determined that the thundercloud is in the developmental period, and when the condition that "the upper atmosphere converges and the atmosphere near the surface diverges during the period when the thundercloud declines," the thundercloud enters the period when it declines. Judge that there is.

In the third thundercloud observation system, the upflow and the downflow are detected from the Doppler radar information, and when the upflow is detected, "a strong upflow occurs during the development period of the thundercloud." The thundercloud is determined to be in the developing period based on the above, and when the downflow is detected, the thundercloud is determined to be in the declining period based on the condition "strong downflow occurs during the thundercloud developing period."

In the fourth thundercloud observation system, the upflow and downflow are detected from the Doppler radar information, and the convection zone and its altitude are detected. It is determined that the thundercloud is in the developing period based on the condition that an updraft occurs, and when a downflow is detected, it is based on the condition that a strong downflow occurs during the thundercloud development period. If it is determined that the thundercloud is in the decline period, and if no vertical direct current is detected, the altitude information of the convection area is used to compare the altitude with the thundercloud discrimination reference altitude. When the condition of "the atmosphere converges and diverges in the upper layer." Is satisfied, it is determined that the thundercloud is in the developing period, and "the upper atmosphere converges and the atmosphere near the surface diverges when the thundercloud declines." When the condition is met, the thundercloud is in the decline period. Determined that that.

[0020]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the processing functions of the thundercloud observation system of the first embodiment. Since the hardware configuration can be realized by a general-purpose computer, its description is omitted here.

In FIG. 1, echo intensity information sent from a weather radar (not shown) as radar information is represented by a polar coordinate system having azimuth, elevation and distance as elements.
This echo intensity information is sent to the water content conversion unit 1. The water content conversion unit 1 converts the echo intensity of each unit mesh into a water content. The converted water content information is CAPPI (constant altitude PPI: Plan Position Indicato).
r) sent to the converter 2.

The CAPPI conversion unit 2 converts the water content information in the polar coordinate system into an orthogonal coordinate system having azimuth, distance and altitude as elements, and the coordinate system conversion information is VIL (vertical direction integrated water content) calculation. Sent to department 3.

The VIL calculator 3 performs a vertical integration process on the water content information converted into the orthogonal coordinate system, and the calculation result is sent to the integrated water content comparison unit 4. The integrated water content comparison unit 4 compares the vertically integrated water content with a thundercloud determination reference value, and detects that the integrated water content is greater than or equal to the reference value. The detection result is the thundercloud detection determination unit 5 Sent to.

On the other hand, the echo intensity information is sent to the echo apex height calculating section 6. The echo apex height calculation unit 6 obtains the height of the highest portion (echo apex) in the range where the echo intensity is equal to or higher than the reference level from the echo intensity information. Sent to department 7.

The echo top temperature conversion unit 7 inputs the high-level meteorological information (currently provided by the Meteorological Agency every 12 hours) indicating the relationship between the altitude and the temperature, and from this information, the echo top altitude is used as the echo top temperature. It is converted, and the converted echo peak temperature is sent to the echo peak temperature comparison unit 8.

The echo top temperature comparison unit 8 compares the echo top temperature with a freezing determination reference value and detects that the echo top temperature becomes equal to or lower than the reference value. The detection result is the thundercloud detection determination unit. Sent to 5.

The thundercloud detection / judgment unit 5 judges that it is a thundercloud based on the comparison results of the integrated water content comparison unit 4 and the echo top temperature comparison unit 8, and determines the possibility of lightning. It is a judgment.

In the above configuration, the processing contents will be described below. First, in the water content conversion unit 1, when the echo intensity information is input, the echo intensity is converted into the water content for each unit mesh. Since this conversion result is expressed in a polar coordinate system, the CAPPI conversion unit 2 converts it into a rectangular coordinate system and
It is sent to the L calculation unit 3. This allows vertical direction integration processing.

Here, the thundercloud has a feature that it grows vertically and a large amount of water is concentrated as compared with a normal rain cloud. Therefore, the VIL calculation unit 3 obtains the vertical direction integrated water content for each unit mesh, and the integrated water content comparison unit 4 compares the integrated water content in each mesh region with the thundercloud determination reference value. The thundercloud detection determination unit 5 detects the presence of a thundercloud by determining the presence or absence of a mesh area having a water content larger than the reference value from the comparison result.

On the other hand, it is known that in order for a thundercloud to strike, ice particles are generated and charged. Therefore, the echo apex altitude calculation unit 6 obtains the altitude of the highest portion (echo apex) in the range where the echo intensity is equal to or higher than the reference level from the echo intensity information, and the echo apex temperature conversion unit 7
Then, the echo top temperature is converted into the echo top temperature based on the high-level meteorological information, and the echo top temperature comparison unit 8 compares it with the freezing determination reference value. When the echo peak temperature is equal to or lower than the reference value, the thundercloud detection determination unit 5 determines that ice particles are formed, and thus determines that the possibility of lightning is high.

As described above, the thundercloud observation system having the above-described configuration uses not only the information on the echo intensity and the echo altitude but also the vertical cumulative water content in consideration of the thundercloud generation and ups and downs mechanisms, so that the thundercloud is determined. Can be accurately detected.

Further, since the presence or absence of freezing is determined by obtaining the echo top temperature, it is possible to determine the degree of lightning possibility. Furthermore, since the altitude / temperature conversion is performed based on the high-rise weather information at the time of observation, it is possible to make a determination regardless of the season, and it is possible to dramatically improve the detection accuracy especially in the winter observation.

FIG. 2 is a block diagram showing the processing functions of the thundercloud observation system of the second embodiment. Since the hardware configuration can be realized by a general-purpose computer here as well, description thereof will be omitted.

In FIG. 2, Doppler information sent from a Doppler radar (not shown) as radar information is sent to the convection zone detection unit 11 and the vertical direct current detection unit 12.
The convection area detection unit 11 detects a convergence area and a divergence area from the Doppler information. Further, the vertical direct current detector 12 detects an upflow and a downflow from the Doppler information.
The detection results of the detection units 11 and 12 are sent to the thundercloud ups and downs determination unit 13.

The thundercloud ups and downs determination unit 13 includes a detection unit 11,
Based on the detection result from 13, the existence of a thundercloud is detected, and it is determined whether the thundercloud is in the developing period or in the decline area.

In the above configuration, the processing contents will be described below. As described above, a thundercloud has a stronger convection than an ordinary rain cloud, and when this thundercloud is captured by a Doppler radar, the convection appears as a Doppler phenomenon. Therefore, the convection area detection unit 11 detects the convergence area and the divergence area from the Doppler information. In this case, since the divergence region is easier to detect than the convergence region, only the divergence region may be detected. Further, the vertical direct current detector 12 detects an upflow and a downflow from the Doppler information.

Here, during the development period of the thundercloud, the phenomenon of convergence occurs below a certain altitude and divergence above. Also, during the decline period, there is a phenomenon of convergence above a certain altitude and divergence below. In the thundercloud ups and downs determination unit 13, the convection area detection unit 1
When the convergence area and divergence area are detected in 1, it is determined that a thundercloud exists, and when the convergence area is lower and the divergence area is higher than the thundercloud discrimination reference altitude, the detected thundercloud develops. If the convergence range is above and the divergence range is below, it is determined that the detected thundercloud is in the decline period.

Even if only the divergent area is detected, it is a simple method, but it is possible to determine the developmental period and the declining period of the thundercloud by comparing with the reference altitude. On the other hand, updrafts occur during the thundercloud development period and downdrafts during the decline period. Therefore,
The thundercloud ups and downs determination unit 13 determines that the detected thundercloud is in the developmental period when the vertical direct current detection unit 12 detects the upflow, and the downward detection of the detected thundercloud when the downflow is detected. It is judged that it is in a period. Furthermore, if it is determined that the nuclear power plant is in the decline period, it is considered that the nucleus is close to the surface of the earth, so it is evaluated that the possibility of a lightning strike is high.

As described above, the thundercloud observation system having the above-mentioned configuration captures the convection phenomenon peculiar to thundercloud rise and fall from the Doppler information, and double-decides the developmental period and the declined period from the detection determination result of convergence / divergence and ascent / descent. Therefore, the detection accuracy of the thundercloud can be improved.

Further, since the period of decline can be discriminated, it is possible to accurately predict not only lightning but also lightning strike occurrence, and it is possible to provide extremely effective information for alarm generation and the like. In the second embodiment, the convection zone detection and the vertical direct current detection are combined, but it is simple but effective even if the detection / determination is performed only in the relatively easy convection zone. . Further, although the first and second embodiments are independent of each other, it goes without saying that the accuracy can be further improved by combining the determination results of both. Other,
The present invention can be similarly implemented even if various modifications are made without changing the gist of the present invention.

[0041]

As described above, according to the present invention, it is possible to accurately detect a thundercloud regardless of the season and to judge the degree of lightning possibility according to the mechanism of generation and rise and fall of the thundercloud. An observation system can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of a first embodiment of a thundercloud observation system according to the present invention.

FIG. 2 is a block diagram showing a functional configuration of a second embodiment of a thundercloud observation system according to the present invention.

FIG. 3 is a conceptual diagram for explaining a thundercloud growth process.

[Explanation of symbols]

1 ... Water content conversion unit, 2 ... CAPPI conversion unit, 3 ... VIL
Calculation unit, 4 ... Integrated moisture amount comparison unit, 5 ... Thundercloud detection determination unit,
6 ... Echo top height calculation unit, 7 ... Echo top temperature conversion unit, 8
... Echo top temperature comparison unit, 11 ... Convection region detection unit, 12 ... Vertical DC detection unit, 13 ... Thundercloud ups and downs determination unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Hashimoto, Inventor 1 Komukai Toshiba Town, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Komu Factory, Toshiba Corporation (72) Yuko Sato Komukai Toshiba, Yuko-ku, Kawasaki City, Kanagawa Prefecture Town No. 1 Incorporation company Toshiba Komukai factory (72) Inventor Ryuichi Muto No. 1 Komukai Toshiba town, Kouki-ku, Kawasaki-shi, Kanagawa Prefecture Incorporation company Toshiba Komukai factory (72) Inventor Yoichi Oba Kawasaki, Kanagawa prefecture Komukai-Toshiba-cho 1-ku, Toshiba Corporation Komukai factory

Claims (8)

[Claims] 1. A moisture content conversion means for inputting echo intensity information of a polar coordinate system as radar information, converting the echo intensity of each unit mesh into a moisture content and converting it to moisture content information of the polar coordinate system, and the means for obtaining the moisture content. The coordinate system conversion means for converting the obtained water content information in the polar coordinate system into the orthogonal coordinate system, the integration processing means for performing the integration processing in the vertical direction with respect to the water content information in the orthogonal coordinate system obtained by this means, and this means An integrated water content comparing means for comparing the integrated water content with a thundercloud judgment reference value, an echo apex altitude calculation means for obtaining an echo apex height at which the echo intensity is equal to or higher than a reference level from the echo intensity information, and a high layer showing a relationship between the altitude and temperature Echo top temperature conversion means for inputting meteorological information and converting the echo top altitude to echo top temperature from this information, and the echo top temperature and freezing judgment reference value obtained by this means. Based on the comparison results of the echo top temperature comparison means to be compared, and the integrated water content comparison means and the echo top temperature comparison means, it is determined that it is a thundercloud and the magnitude of the possibility of lightning is determined. And a thundercloud observation system. 2. The determining means, when the integrated water content comparison means detects an integrated water content equal to or greater than a thundercloud determination reference value, determines that the accumulated water content is a thundercloud, and the echo top temperature comparison means determines that the echo top temperature is The thundercloud observation system according to claim 1, wherein it is determined that the possibility of lightning is high when it is detected that the value is equal to or less than the freezing determination reference value. 3. A convection zone detecting means for receiving the Doppler radar information to detect the convection zone and its altitude, and a thundercloud ups and downs determination means for judging the ups and downs of the thundercloud based on the altitude information of the convection zone detected by this means. Thundercloud observation system equipped with. 4. The thundercloud ups and downs determination means compares the altitude of the convection area detected by the convection area detection means with a thundercloud discrimination reference altitude, and based on the comparison result, whether the thundercloud is in the developmental period or the decline period. The thundercloud observation system according to claim 3, wherein it is determined whether or not 5. A thundercloud observation system comprising a vertical direct current detecting means for receiving Doppler radar information to detect an upflow and a downflow, and thundercloud ups and downs determining means for determining ups and downs of a thundercloud based on the detection result of this means. . 6. The thundercloud ups and downs determination means determines that the thundercloud is in a developmental period when an upflow is detected by the vertical direct current detection means, and determines that the thundercloud is in a declined period when a downflow is detected. The thundercloud observation system according to claim 5, wherein 7. A vertical direct current detecting means for receiving Doppler radar information to detect an upflow and a downflow; a convection area detecting means for receiving the Doppler radar information to detect a convection zone and its altitude; Means and a thundercloud ups and downs determination means for determining ups and downs of a thundercloud based on the detection result of the convection area detection means. 8. The thundercloud ups and downs determination means determines that the thundercloud is in a developmental period when an upflow is detected by the vertical direct current detection means, and determines that the thundercloud is in a declined period when a downflow is detected. However, when vertical flow is not detected by this means, the altitude of the convection area detected by the convection area detection means is compared with the thundercloud discrimination reference altitude, and whether the thundercloud is in the developing stage based on the comparison result. The thundercloud observation system according to claim 7, wherein it is determined whether or not it is in a decline period.