JPH07110378A - Thundercloud observation system - Google Patents

Abstract

PURPOSE:To accurately detect thundercloud according to the mechanism of generation and ups and downs of the thundercloud regardless of seasons and judge the probability of thunder occurrence by obtaining the height of the top of echo intensity range over a reference level from echo intensity information. CONSTITUTION:Every time echo information from a weather radar is renewed, processed results obtained at an echo top temperature calculation part 2, a vertical direction integral moisture amount value calculation part 4, a cell special part 5 and a tropospheric region detection part 6 are stored in a thundercloud history file production and storage part 7 as a thundercloud history file information indicating the history of the thundercloud. A correlation judgment part 8 calculates the cell gravity center position from the new file produced in the storage part 7, compares it with the cell gravity center position in the part file and judges the equalness of them. Also, a thundercloud ups and downs judgment part 9 judges whether the cloud appearing on a radar echo is thundercloud on the basis of the new file information including the additional information of the judgment part 8 from the storage part 7 and which process of developing, matured or falling the thundercloud belongs to.

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.

[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, the detection rate is low, 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]

In order to achieve the above object, the thundercloud observation system according to the present invention is an echo top height calculating means for obtaining the height of the apex of the echo intensity range of the reference level from the echo intensity information from the weather radar. , And an echo peak temperature conversion means for converting the echo peak height to an echo peak temperature based on high-level weather information indicating the relationship between altitude and temperature, and converting the echo intensity of each unit mesh from the echo intensity information into a water content. , A cumulative water content calculation means for performing vertical integration processing, and the cumulative water content by this means are compared with a thundercloud judgment reference value, and the range in which the cumulative water content exceeds the reference value is specified as a cell indicating the thundercloud region. Cell identification means,
A convection zone detecting means for detecting the presence or absence of a convection zone and its altitude from the Doppler radar from the Doppler radar, and the echo top temperature converting means, every time the echo intensity information from the weather radar is updated, an integrated water content calculating means, A thundercloud history file creation and storage unit that creates and stores a thundercloud history file by collectively storing the processing results of the cell identification unit and the convection area detection unit together with associated information at the time of updating, and a cell by the cell identification unit when updating the echo intensity information. Is specified, the thundercloud represented by the cell based on the processing results of the echo apex temperature conversion means, the integrated water content calculation means and the convection area detection means, one of the development period, the maturity period, and the decline period. Judge,
Thundercloud ups and downs determination means for storing the determination result as incidental information in the thundercloud history file creation and storage means and the latest file in the thundercloud history file creation and storage means to determine the possibility of lightning based on the file information. And a lightning determination means for determining.

[0013]

In the thundercloud observation system having the above-mentioned configuration, the altitude of the apex of the echo intensity range of the reference level is obtained from the echo intensity information, the echo apex altitude is converted to the echo apex temperature based on the high-level meteorological information, and the unit is calculated from the echo intensity information. The echo intensity of each mesh is converted to the amount of water, the vertical direction integration process is performed, and the result of this process is compared with the thundercloud judgment reference value to identify the cell that indicates the thundercloud region, and whether there is a convection region from the Doppler information. And its altitude, echo echo temperature obtained each time the echo intensity information is updated, integrated water content, cell identification result and convection area detection result, along with the accompanying information at the time of updating the correlation determination result, ups and downs determination result. A thundercloud history file is created and stored collectively, and the possibility of lightning is determined for the latest file based on the file information.

[0014]

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, the echo apex height calculating unit 1 obtains the height of the apex of the echo intensity range of a reference level (for example, 30 dBz) from echo intensity information from a weather radar (not shown). The echo peak height information obtained here is sent to the echo peak temperature conversion unit 2.

The echo top temperature conversion unit 2 refers to the altitude / temperature data table 3 to obtain the temperature at the echo top altitude. The data of the altitude / temperature data table 3 is created based on, for example, high-level weather information announced by the Meteorological Agency.

On the other hand, the VIL (vertical direction integrated water content) intensity calculation unit 4 converts the echo intensity of each unit mesh from the echo intensity information into the amount of water, and performs the vertical direction integration process to obtain the VIL for each mesh. Find strength. The VIL strength information obtained here is sent to the cell identification unit 5.

This cell identification unit 5 is used for VI in each mesh.
The L intensity is compared with a thundercloud determination reference value, and a range in which the integrated water content is equal to or greater than the reference value is specified as a cell indicating a thundercloud region. Further, the convection zone detection unit 6 detects the presence or absence of the convection zone and its altitude from the Doppler information from a Doppler radar (not shown).

Every time the echo intensity information from the weather radar is updated, the processing results obtained by the echo apex temperature conversion unit 2, the VIL intensity calculation unit 4, the cell identification unit 5 and the convection region detection unit 6 are obtained. Is stored in the thundercloud history file creation storage unit 7 as thundercloud history file information indicating the history of thunderclouds. At this time, the determination information by the correlation determination unit 8 and the thundercloud ups and downs determination unit 9 described later is also added to the thundercloud history file information (hereinafter referred to as accompanying information).

The correlation determining section 8 reads the VIL intensity in the latest cell from the new file created in the thundercloud history file storage section 7, calculates the cell center of gravity position, and compares it with the cell center of gravity position of the past file. The degree of change is used to determine the identity of the two, and the determination result is included in the new file as accompanying information together with the information on the cell centroid position.

Further, the thundercloud ups and downs determination unit 9 determines that the cloud reflected in the radar echo is a thundercloud based on the new file information including the accompanying information of the correlation determination unit 8 from the thundercloud history file creation storage unit 7. At the same time, it is determined whether the thundercloud is in a developmental period, a maturity period, or a decline period, and the determination result is included in a new file as accompanying information.

The new file information created in the thundercloud history file creation storage unit 7 in this manner is sent to the lightning determination unit 10. The lightning strike determination unit 10 specifically determines the degree of possibility of lightning strike based on the input file information, and provides information serving as an index such as an alarm.

In the above configuration, first, the determination conditions will be described. When the cell identification unit 5 can identify a cell, it is determined that the cloud in the cell area is a thundercloud. This is based on the characteristic of thunderclouds that "thunderclouds have more water content than ordinary rain clouds."

When the convection area is detected, the altitude is compared with the thundercloud discrimination reference altitude. From the result,
When the condition that "the atmosphere near the surface of the thundercloud converges and diverges in the upper layer during the development period of the thundercloud" is satisfied, it is determined that the thundercloud is in the development period, and "the upper atmosphere converges during the period of thundercloud decline. ,
The atmosphere near the surface emits. If the condition of “” is satisfied, it is determined that the thundercloud is in the decline period.

Further, when the echo top temperature is compared with the freezing determination reference value and is detected to be equal to or lower than the freezing determination reference value, it is considered that the ice particles that are the cause of lightning are generated. , It is judged that the thundercloud is in maturity or decline. Here, for example, by looking at the VIL intensity at the echo apex height, it is possible to discriminate the maturity period when the VIL intensity becomes extremely strong due to the formation of nuclei at the echo apex height, as is clear from FIG.

Further, when the new cell is judged to be the same as the cell in the past file information by the correlation judgment, the difference in VIL intensity between the new cell and the immediately preceding cell (VIL change amount) is calculated. It is calculated and compared with the reference value to distinguish the developmental period and the decline period. This is based on the characteristic of thunderclouds that "the amount of water increases drastically during the development period, and there is almost no increase in the water amount during the maturity period and the decline period."

Since the determination result here is more accurate than the determination result by the convection zone detection, this is prioritized. However, the condition is that there is a correlation with the past cell (when it is determined to be the same), and if there is no correlation, it is based on the determination result by convection zone detection.

If the file information correlated in the past has a history of maturity, it is possible to determine that the file is at least after the decline. The lightning strike determination is basically based on the result of the thundercloud ups and downs. That is, since a charged nucleus is formed in the maturation period and the decline period, there is a high possibility of lightning. This state is called "strong thunder" here. Although the nucleus has not been formed yet in the developmental period, the water content is considerably higher than that of a normal rain cloud, so there is a good possibility of lightning. Here, this state is called "middle thunder". Furthermore, if the water content of the cloud is large, there is a high possibility that it will progress to the developmental stage in the future. Here, this state is called "light thunder".

If none of the judgment conditions is satisfied, it is judged that no thundercloud has occurred, and the ups and downs judgment is not performed, and the lightning judgment is "none". FIG. 2 illustrates a concrete algorithm of the thundercloud ups and downs determination and the lightning emission determination created based on the above determination conditions.

In step (1), "cell identification",
Classification is made based on "cell unspecified". When a cell can be identified, it is highly likely that the cell is a thundercloud. If it cannot be specified, it is assumed that there is no thundercloud, the ups and downs are not judged, and the lightning is judged to be “none”.

In step (2), "-20.degree. C." is compared with the echo top temperature as a freezing judgment reference value, and "-20.degree.
Classification is made according to "below ℃" and "higher than -20 ℃". In step (3), the maximum VIL intensity for each mesh in the cell is calculated, and the VIL intensity of 15 mm / H is used as the thundercloud determination reference value and 30 mm / H is the nuclear determination reference value, and the value of “30 mm / H is determined.
Above, ”“ 15 to 30 mm / H 2 ”, and“ less than 15 mm / H 2 ”are used for classification.

In step (4), referring to the convection area information (herein, for simplification of explanation, the presence or absence of a divergence area and its altitude information) is set, the thundercloud judgment altitude is set to 3 km, and
Classification is made based on "There is a divergence area over 3km", "There is a divergence area under 3km", and "Unknown". If there is no correlation, as shown by the dotted line in the figure, ups and downs determination and lightning determination are performed according to the classification so far.

If there is a correlation, in step (5), the reference value for the VIL change is +5 mm / H /
3 minutes (generally, one observation scan of the observation radar is 3 minutes), "+ 5mm / H / 3 minutes or more", "+ 5mm
/ H / less than 3 minutes ”. In step (6), classification is made as “with rise / fall history” and “without rise / fall history”.

From the above classification results, in the ups and downs judgment of step (7), "development period", "maturity period", "decline period"
"Undetermined" is determined, and in the lightning determination of step (8), "strong thunder", "medium thunder", "weak thunder", and "none" are determined.

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 as a judgment material in consideration of the thundercloud generation and rise / fall mechanisms. Can be accurately detected.

Moreover, since the presence or absence of icing is determined by obtaining the echo top temperature, it is possible to perform ups and downs determination and lightning determination with high accuracy. In particular, the altitude /
Since the temperature conversion is performed, the determination can be performed regardless of the season, and the detection accuracy in winter observation can be dramatically improved.

Furthermore, a series of file information in the past can be used by the correlation judgment, and the judgment can be performed with higher accuracy. On the other hand, the convection phenomenon peculiar to thundercloud rise and fall is grasped from the Doppler information, and the development / discrimination period is shown from the convergence / divergence detection discrimination
Since the period of decline is determined, correlation cannot be obtained, and thundercloud ups and downs and lightning can be determined even if past file information cannot be used.

When the lightning strike location information is obtained, it can be used for accuracy evaluation of the system by storing it as incidental information in the thundercloud history file creation storage unit 7 as shown in FIG. Besides, the present invention is not limited to the above-described embodiments, and can be similarly implemented by various modifications without changing the gist thereof.

[0039]

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 an embodiment of a thundercloud observation system according to the present invention.

FIG. 2 is a block diagram illustrating a thundercloud ups and downs determination / lightning determination algorithm of the thundercloud observation system according to the present invention.

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

[Explanation of symbols]

1 ... Echo top height calculation unit, 2 ... Echo top temperature conversion unit, 3
... Altitude / temperature data table, 4 ... VIL (vertical direction integrated water content) intensity calculation unit, 5 ... Cell identification unit, 6 ... Convection region detection unit, 7 ... Thundercloud history file creation storage unit, 8 ... Correlation determination unit, 9 ... thundercloud ups and downs determination unit, 10 ... thunderlight determination unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuko Sato Yuko Sato 1 Komukai Toshiba Town, Saiwai-ku, Kanagawa Prefecture Komu Factory, Toshiba Corporation (72) Hideki Hashimoto Komukai Toshiba, Kawasaki City, Kanagawa Prefecture Town No. 1 Incorporation company Toshiba Komukai Plant (72) Inventor Hiroshi Oikawa Komukai Toshiba Town No. 1, Komukai-ku, Kawasaki City, Kanagawa Prefecture Incorporation company Toshiba Komukai Plant (72) Inventor Satoshi Nakano Kawasaki City, Kanagawa Prefecture Komukai-Toshiba-cho, 1-ku, Toshiba Corporation Komukai factory

Claims (6)

[Claims] 1. An echo apex height calculating means for obtaining an altitude of a vertex of an echo intensity range of a reference level from echo intensity information from a meteorological radar, and the echo apex height based on high level meteorological information showing a relation between altitude and temperature. Echo top temperature conversion means for converting to echo top temperature, integrated water content calculation means for converting the echo strength of each unit mesh into water content from the echo intensity information, and performing vertical integration processing, and integrated water content by this means Compare the amount with the thundercloud judgment reference value,
Cell specifying means for specifying a range in which the amount of accumulated water is a reference value or more as a cell indicating a thundercloud area, convection area detecting means for detecting the presence or absence of a convection area and its altitude from Doppler information from the Doppler radar, Every time the echo intensity information from the radar is updated, the processing results of the echo apex temperature conversion means, the integrated water content calculation means, the cell identification means and the convection area detection means are collected together with the accompanying information at the time of updating the thundercloud history file. Thundercloud history file creating and storing means for creating and storing, and when the cell is specified by the cell specifying means at the time of updating the echo intensity information, each of the echo top temperature converting means, the integrated water content calculating means and the convection area detecting means Based on the processing result, the thundercloud represented by the cell determines whether it is a developmental period, a maturity period, or a decline period, and the determination result is attached to the update time. As a report, a thundercloud ups and downs determination means to be stored in the thundercloud history file creation and storage means, and a thunderstorm determination means to determine the possibility of a lightning strike based on the file information of the latest file of the thundercloud history file creation and storage means Thundercloud observation system. 2. The thundercloud ups and downs determination means is in a developmental stage or declines based on the result of comparison between the altitude of the convection zone detected by the convection zone detection means and the thundercloud discrimination height for the cell identified by the cell identification means. The thundercloud observation system according to claim 1, wherein it is determined that the echo top temperature is in a mature stage when the echo top temperature reaches a freezing temperature. 3. The thundercloud observation system according to claim 2, wherein the lightning strike determination means classifies the degree of lightning possibility according to the determination result of the thundercloud ups and downs determination means. 4. The correlation between the latest cell obtained by the cell specifying means and the past cell stored in the thundercloud history file creating / storing means is used to determine the sameness, and the determination result is updated. Correlation information storage means for storing in the thundercloud history file creation storage means as incidental information of the thundercloud history file creation storage means, and the latest cell obtained by the correlation processing means is stored in the thundercloud history file creation storage means. The thundercloud observation system according to claim 1, wherein when it is determined that the cell is the same as a past cell, the possibility of lightning is determined by referring to past file information. 5. The thundercloud ups and downs determination means, when the correlation processing means determines that the latest cell is the same as the past cell, refers to the thundercloud history file and determines that the maturity period is in the past. The thundercloud observation system according to claim 4, wherein it is determined whether or not there is a decline period regardless of the detection result of the convection area detection means by determining whether or not there is a presence. 6. The thundercloud ups and downs determining means refers to the thundercloud history file when the correlation processing means determines that the latest cell is the same as the past cell, and the vertical cumulative moisture content of the latest cell. 5. The thundercloud observation system according to claim 4, wherein the development period and the decline period are determined by comparing the difference between the vertical integration moisture content of the cell before 1 update and the reference level. .