An objective positioning system for the remnant vortex of a tropical cyclone

Abstract

This invention discloses an objective positioning system for remnant vortices of tropical cyclones, comprising: a tropical cyclone discontinuation location identification module for accessing a cyclone path dataset and parsing historical path records of individual tropical cyclones; a discontinuation identification judgment module for determining whether the remnant vortex has dissipated based on preset meteorological field threshold parameters from the time the tropical cyclone discontinuation occurred; if the remnant vortex is determined to have dissipated, a remnant vortex dissipation judgment command is sent to the output tropical cyclone remnant vortex location module; if the remnant vortex is determined to still exist, the tropical cyclone remnant vortex identification module is triggered; the tropical cyclone remnant vortex identification module is used to calculate the remnant vortex center position at the current time step within the search area; and the output tropical cyclone remnant vortex location module is used to integrate and output the trajectory data of the remnant vortex center position changing over time from the time the tropical cyclone discontinuation occurred until the determination of remnant vortex dissipation.

Description

Technical Field

[0001] This invention relates to the field of tropical cyclone weather forecasting technology, specifically an objective positioning system for the remnant vortex of a tropical cyclone. Background Technology

[0002] The remnant vortex of a tropical cyclone refers to the low-level circulation structure that continues to exist and move as a weakened low-pressure system after a typhoon has dissipated or weakened to below tropical depression level (maximum wind speed near the typhoon center drops below 10.8 m / s). The intensity of tropical cyclone precipitation is not a simple linear relationship with the intensity of the tropical cyclone or its core convection. Numerous observations demonstrate that the intensity of rainfall generated by the remnant vortex can exceed that of a strong typhoon. Several of the most severe extreme precipitation events affecting China, such as the "96•8" Hebei torrential rain and the "23•7" North China torrential rain, are closely related to the remnant vortex of tropical cyclones. Locating the remnant vortex is fundamental to related research; therefore, objectively locating the remnant vortex has significant scientific and practical importance.

[0003] There is relatively little research on the objective location of remnant vortices of tropical cyclones. Currently, the determination of remnant vortices of tropical cyclones is mainly based on subjective human judgment. For example, Ritchie et al. (2011) used infrared (IR) and water vapor (WV) images from the GOES satellite to determine the location of the remnant vortex every 3 hours until the remnant vortex dissipated. Meng Zhaozhen et al. (2017) defined a remnant vortex of a tropical cyclone as a low-pressure circulation that maintains a lifespan of more than 24 hours when the typhoon stops being numbered or the maximum wind speed near the typhoon center drops below 10.8 m / s. This low-pressure circulation meets one of the following conditions: (1) there is a closed circulation with a contour line of 148 dagpm or less at 850 hPa; (2) there is a closed low pressure with an isobar of 1000 hPa or less at the ground; (3) unconventional data (automatic weather station wind field, radar echo, satellite data) show the presence of a low-pressure circulation. Lin et al. (2016) used the minimum value of the 850 hPa stream function to objectively determine the location of the typhoon remnant vortex. However, combining the pressure field and flow field with the previous typhoon path to track the typhoon remnant vortex may yield better objective identification results, especially reducing the objective identification error when two typhoons exist. Summary of the Invention

[0004] The purpose of this invention is to provide an objective positioning system for the residual vortex of tropical cyclones, in order to solve the problems of the prior art.

[0005] This invention discloses an objective positioning system for remnant vortices of tropical cyclones, comprising: a tropical cyclone discontinuation location identification module, a discontinuation identification and judgment module, a tropical cyclone remnant vortex identification module, and a tropical cyclone remnant vortex output module. The tropical cyclone discontinuation location identification module accesses a cyclone path dataset, analyzes historical path records of individual tropical cyclones, determines the discontinuation time and the corresponding discontinuation location, and transmits the discontinuation time and location as an initial spatiotemporal reference to the discontinuation identification and judgment module. The discontinuation identification and judgment module, starting from the tropical cyclone discontinuation time, periodically calls meteorological reanalysis data according to a preset time step, and at each time step, identifies the tropical cyclone center or remnant vortex determined in the previous time step. The search area is constructed based on the residual vortex center, and the remnant vortex is judged to have dissipated based on preset meteorological field threshold parameters. If the remnant vortex is determined to have dissipated, a remnant vortex dissipation judgment command is sent to the tropical cyclone remnant vortex position module. If the remnant vortex is determined to still exist, the tropical cyclone remnant vortex identification module is triggered. The tropical cyclone remnant vortex identification module is used to calculate the position of the remnant vortex center at the current time step within the search area, and transmits the center position to the stop identification judgment module as the reference for constructing the search area at the next time step. The output tropical cyclone remnant vortex position module is used to integrate and output the trajectory data of the remnant vortex center position changing over time from the tropical cyclone cessation time until the remnant vortex is determined to have dissipated.

[0006] According to an embodiment of the system of the present invention, the tropical cyclone stop-editing location identification module uses the tropical cyclone number as an index to analyze the corresponding path records in chronological order. When it is identified that the maximum wind speed near the center of the tropical cyclone drops to a preset threshold or below for the first time, the time corresponding to that time is determined as the stop-editing time, and the latitude and longitude coordinates corresponding to that time are determined as the stop-editing location.

[0007] According to an embodiment of the system of the present invention, the preset threshold is 10.8 m / s, and when the maximum wind speed near the center of a tropical cyclone is detected to drop below 10.8 m / s, and the maximum wind speed near the center of the tropical cyclone does not recover to 10.8 m / s or above in subsequent observation times, the time corresponding to that time is determined as the stop-editing time, and the latitude and longitude coordinates corresponding to that time are determined as the stop-editing position.

[0008] According to an embodiment of the system of the present invention, the stop identification and judgment module determines the persistence of residual vortices within the search area based on preset meteorological field threshold parameters, including: determining based on the geopotential height field, the stream function field, and the relative vorticity field, and determining that the residual vortex has disappeared when any of the following conditions are met: there is no closed contour line with a geopotential height value less than or equal to the preset threshold within the search area; the extreme value of the stream function is positive at the current time step; or the extreme value of the relative vorticity is negative at the current time step.

[0009] According to one embodiment of the system of the present invention, the stop identification and judgment module extracts the geopotential height field and wind field at the 850 hPa isobaric surface layer based on ERA5 reanalysis data, and calculates the stream function field based on the wind field to extract the relative vorticity field.

[0010] According to one embodiment of the system of the present invention, the threshold for determining the closure of the contour line of the potential height is 148 dagpm.

[0011] According to one embodiment of the system of the present invention, the stop identification and judgment module constructs a circular search area with a radius of 300 km with the stop position or the residual vortex center position of the previous moment as the center. At each time step after the stop, ERA5 reanalysis data is called sequentially for judgment according to a time cycle of 6 hours.

[0012] According to an embodiment of the system of the present invention, the tropical cyclone residual vortex identification module determines the minimum point of the geopotential height field, the maximum point of the relative vorticity field, and the minimum point of the stream function field within the same search area as the stop identification judgment module, and determines the position of the residual vortex center at the current time step based on the three extreme points.

[0013] According to an embodiment of the system of the present invention, when the tropical cyclone remnant vortex identification module calculates the location of the remnant vortex center, it converts the latitude and longitude coordinates of the three extreme points into three-dimensional rectangular coordinates, averages the converted three-dimensional coordinates, and then back-calculates them into latitude and longitude coordinates, using the back-calculated latitude and longitude coordinates as the location of the remnant vortex center.

[0014] According to an embodiment of the system of the present invention, the integrated output of the trajectory data of the tropical cyclone remnant vortex location module includes: generating a basic positioning dataset containing time, longitude coordinate fields, and latitude coordinate fields for the remnant vortex data at each time point; associating and storing the stream function extreme value parameter field, relative vorticity extreme value parameter field, and geopotential height extreme value parameter field corresponding to each time point; marking the remnant vortex data after the stop editing time with a termination identifier, and generating a termination report file containing complete meteorological elements.

[0015] The present invention provides an objective positioning system for remnant vortices of tropical cyclones, which can quantitatively determine the existence and location of remnant vortices of tropical cyclones, thereby achieving objective positioning of remnant vortices of tropical cyclones. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0017] Figure 2 The diagram shows the workflow of the system of the present invention.

[0018] Figure 3 This is the header file format for optimal tropical cyclone track data;

[0019] Figure 4 This is the optimal path data recording format for tropical cyclones. Detailed Implementation

[0020] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0021] Figure 1 The diagram shown is a block diagram of an objective positioning system for residual vortices of tropical cyclones according to the present invention. Figure 1 As shown, the objective positioning system for residual vortices of tropical cyclones of the present invention includes: a tropical cyclone stop location identification module, a stop identification judgment module, a module for outputting the location of residual vortices of tropical cyclones, and a module for identifying residual vortices of tropical cyclones.

[0022] like Figure 1 As shown, the tropical cyclone termination location identification module accesses the cyclone path dataset and analyzes the historical path records of individual tropical cyclones. The cyclone path dataset can be a dataset of optimal paths for tropical cyclones in the Northwest Pacific, which can be obtained through pre-downloaded data files or online data interfaces. The cyclone path dataset can contain information such as the tropical cyclone number, the center location of the tropical cyclone at different times during its life cycle, and the maximum wind speed near the center.

[0023] The tropical cyclone discontinuation location identification module uses the tropical cyclone number as an index to analyze the corresponding path records in chronological order. When it identifies a tropical cyclone whose maximum wind speed near the center drops to a certain threshold and does not recover above that threshold, the corresponding time is determined as the tropical cyclone's discontinuation time, and the corresponding latitude and longitude coordinates are determined as the tropical cyclone's discontinuation location. If no instance of a maximum wind speed near the center falling below a threshold occurs in the entire path record, the last valid time in the tropical cyclone's path record and its corresponding latitude and longitude coordinates are taken as the discontinuation time and discontinuation location. The discontinuation time and discontinuation location serve as the initial spatiotemporal reference for subsequent residual vortex identification processes, are recorded, and transmitted to the discontinuation identification judgment module as parameters.

[0024] like Figure 1 As shown, in a preferred embodiment, the tropical cyclone discontinuation location identification module uses the tropical cyclone number as an index to analyze the corresponding path records in chronological order. When it is identified that the maximum wind speed near the center of the tropical cyclone drops below 10.8 m / s and does not recover to 10.8 m / s or above in subsequent observation periods, the time corresponding to that observation period is determined as the discontinuation time of the tropical cyclone, and the latitude and longitude coordinates corresponding to that observation period are determined as the discontinuation location of the tropical cyclone. If there is no instance of the maximum wind speed near the center being lower than 10.8 m / s in the entire path record, then the last valid time in the tropical cyclone path record and its corresponding latitude and longitude coordinates are taken as the discontinuation time and discontinuation location.

[0025] For example, a tropical cyclone number is a unique numerical identifier assigned to tropical disturbances that form in the Northwest Pacific and South China Sea and reach tropical storm strength, based on their formation time sequence. The main purpose of these numerical identifiers is to facilitate meteorological monitoring, early warning issuance, and international information exchange, avoiding confusion caused by naming differences between different countries or regions. Tropical cyclone numbers typically consist of the year plus a sequential number. For example, the third tropical cyclone to reach tropical storm strength in 2024 is numbered 2403. When the maximum mean wind speed near the typhoon's center weakens to below 10.8 m / s, or when the typhoon moves north to a higher latitude and its structure is affected by cold air and other factors, losing its warm core characteristics and transforming into an "extratropical cyclone," the China Meteorological Administration will cease numbering it; this is known as the cessation of tropical cyclone numbering. The spatiotemporal feature data can contain four columns in CSV format. Each column represents the tropical cyclone number, the time when the numbering stopped (UTC), the latitude of the typhoon at the time of the numbering stopping, and the longitude of the typhoon at the time of the numbering stopping. For example, 2403 2024072800 29.5 114.2 means that Typhoon No. 2403 stopped being numbered at 00:00 on July 28, 2024, and its position at the time of the numbering stopping was 29.5°N, 114.2°E.

[0026] like Figure 1As shown, the stop identification and judgment module is used to determine the persistence of residual vortices based on preset meteorological field threshold parameters. Through multi-dimensional meteorological element coupling analysis, the persistence of the closed circulation system is determined. If the system meets the criteria of no closed circulation, a stream function extremum, or a vorticity extremum exceeding the threshold range, the stop identification and judgment module's result is "yes," and the system will stop residual vortex identification and execute the output tropical cyclone residual vortex location module. Otherwise, the system will not stop identification and will execute the tropical cyclone residual vortex identification module.

[0027] like Figure 1 As shown, specifically, the stop identification and judgment module uses the stop-editing position as the previous tropical cyclone center position. At each time step after the stop-editing, it calls up data for analysis and judgment at certain time intervals. The stop identification and judgment module constructs a search area based on the tropical cyclone center or remnant vortex center determined at the previous moment to limit the spatial range for remnant vortex determination and location, thereby ensuring the continuity of the identification process in time and space. The stop identification and judgment module makes judgments within the search area. When there are no closed contour lines with geopotential height values ​​less than a threshold within the search area, or the current stream function extreme value is positive, or the current relative vorticity extreme value is negative, it is determined that the tropical cyclone remnant vortex has dissipated, the subsequent identification process stops, and the process enters the result output stage.

[0028] like Figure 1 As shown, in a preferred embodiment, the stop identification and judgment module uses the stop location as the position of the tropical cyclone center at the previous moment. At each time step after the stop location, ERA5 reanalysis data is sequentially called for judgment at 6-hour intervals. ERA5 reanalysis data can be obtained through pre-download or online interface, and includes meteorological elements such as wind fields and geopotential height fields at different pressure levels. At each time step, the stop identification and judgment module constructs a circular search area with a radius of 300 km, centered on the tropical cyclone center or remnant vortex center determined at the previous moment, to limit the spatial range for remnant vortex determination and location, thereby ensuring the continuity of the identification process in time and space.

[0029] like Figure 1As shown, in a preferred embodiment, within the search area, the stop identification and judgment module extracts geopotential height field, stream function field, and relative vorticity field information from the 850 hPa isobaric surface layer based on ERA5 reanalysis data. The geopotential height field and relative vorticity field can be directly obtained from the ERA5 reanalysis data, while the stream function field is calculated based on the wind field grid data in the ERA5 reanalysis data. The geopotential height field is used to determine whether the low-pressure circulation still maintains an independent closed structure, the stream function field is used to characterize the rotational properties of the circulation, and the relative vorticity field is used to reflect the vortex intensity characteristics. The stop identification and judgment module analyzes and judges the above physical quantities. When there are no closed contour lines with a geopotential height value less than or equal to 148 dagpm within the search area, or the current stream function extreme value is positive, or the current relative vorticity extreme value is negative, it determines that the remnant vortex of the tropical cyclone has dissipated, stops the subsequent identification process, and enters the result output stage. If none of the above termination conditions are met, it is determined that the residual vortex of the tropical cyclone still exists, and the residual vortex identification module of the tropical cyclone calculates the position of the center of the residual vortex at the current moment.

[0030] Specifically, the 850 hPa level is representative of the lower troposphere, reflecting the characteristics of surface pressure systems effectively while avoiding complex interferences caused by near-surface friction and topography. The warm core structure and circulation of tropical cyclones are clearly evident at this altitude. The 148 dagpm threshold is an empirical climatic threshold used to identify low-pressure systems significantly lower than their surroundings and possessing independent closed circulation. If even a relatively weak closed low-pressure center cannot be maintained, it indicates that the residual vortex has essentially disintegrated. The 300km radius is used because only 3.3% of the samples from 1960-2024 typhoons in the Northwest Pacific had movement speeds >50km / h. A 6-hour movement of 300km effectively limits the determination of residual vortices. Based on continuous tracking with the previous state (6 hours prior), the determination ensures that it is based on the same system, rather than a misidentification of different systems, guaranteeing temporal and spatial continuity. When the extreme value of the stream function near the center of the residual vortex changes from negative to positive, it signifies a shift from cyclonic rotation to anticyclonic rotation, a strong signal of circulation dissipation. Similarly, when the extreme value of relative vorticity changes from positive to negative, it indicates the complete disappearance of the cyclonic vortex intensity. This approach integrates three independent yet physically related fields: the mass field (potential height), circulation properties (stream function), and vortex intensity (relative vorticity). It is more robust than a single criterion and effectively prevents misjudgments caused by single data errors or instantaneous fluctuations.

[0031] like Figure 1As shown, the tropical cyclone remnant vortex identification module calculates the center position of the tropical cyclone remnant vortex at the current moment within the search area. This center position is recorded and transmitted to the stop identification judgment module in the form of parameters, serving as the center reference of the spatial search area in the next time step, and participating in the next round of remnant vortex existence determination and location calculation.

[0032] like Figure 1 As shown, in a preferred embodiment, the tropical cyclone remnant vortex identification module, within the same 300km search area as the stop identification judgment module, calculates the minimum points of the geopotential height field, the maximum points of the relative vorticity field, and the minimum points of the stream function field based on ERA5 reanalysis data of the 850 hPa isobaric surface layer. These three extreme points reflect the characteristics of the remnant vortex from the perspectives of the mass field, vortex intensity field, and circulation structure, respectively. Based on the characteristics of the remnant vortex, the center position of the tropical cyclone remnant vortex at the current moment is calculated. This center position includes the corresponding longitude and latitude coordinates and is recorded as the calculation result for that time node.

[0033] like Figure 1 As shown, in a preferred embodiment, since directly averaging latitude and longitude may introduce spatial errors, when calculating the location of the residual vortex center, the latitude and longitude coordinates of the three extreme points are first uniformly converted into coordinates in a three-dimensional rectangular coordinate system. After averaging the converted three-dimensional coordinates, the average result is then converted back into latitude and longitude coordinates. The latitude and longitude obtained from the back calculation is taken as the location of the center of the residual vortex of the tropical cyclone at the current moment, and is called the average location of the three extreme points. The location of the residual vortex center and the corresponding extreme parameters of geopotential height, stream function, and relative vorticity are recorded as the calculation results of this module and used for subsequent loop judgments and result output.

[0034] like Figure 1 As shown, after determining that the residual vortex has dissipated, the module for outputting the location of the tropical cyclone residual vortex integrates the data obtained throughout the identification process. Specifically, the output includes complete trajectory data of the residual vortex center position changing over time. This trajectory data includes at least time nodes, longitude coordinate fields, and latitude coordinate fields, and simultaneously stores the geopotential height extreme parameters, stream function extreme parameters, and relative vorticity extreme parameters corresponding to each time node. For the time node where the residual vortex dissipates, a termination marker is added to the corresponding data. The output generates two files: one is a detailed record of the residual vortex information at each moment (including the geopotential height, stream function, location and intensity of the relative vorticity extreme points in the identified area), and the other is a residual vortex trajectory dataset. It is preferred to store the data in structured CSV format for ease of subsequent analysis, processing, and business applications.

[0035] This invention provides an objective positioning system for remnant vortices of tropical cyclones. In actual operation, it uses the tropical cyclone termination number as a starting point and combines reanalysis meteorological data to continuously and objectively identify and track the existence and center location of remnant vortices. Through the above implementation, this invention, after the tropical cyclone termination number, can continuously, stably, and objectively locate and identify remnant vortices without relying on subjective human judgment, effectively improving the reliability and consistency of remnant vortex identification results.

[0036] A specific implementation of the objective positioning system for the remnant vortex of a tropical cyclone according to the present invention is as follows:

[0037] Typhoon Gemi, the third typhoon of 2024, formed in the ocean east of the Philippines at 06 UTC on July 20. After its formation, it moved northwestward and then northward, gradually intensifying. It strengthened into a super typhoon at 02 UTC on July 24, and made landfall as a strong typhoon in Nan'ao Township, a county in Fujian Province (48 m / s, 945 hPa) around 16 UTC on July 24. After landfall, it crossed the northern part of an island and entered a strait, gradually weakening. It made a second landfall as a typhoon in Xiuyu District, Putian City, Fujian Province (33 m / s, 972 hPa) around 11:50 UTC on July 24. After landfall, Gemi slowly weakened and moved in a north-northwest direction. Around 09 UTC on July 26, it entered Jiangxi Province from Fujian Province, continuing to weaken. Around 09 UTC on July 27, it entered Hubei Province from Jiangxi Province and weakened into a tropical depression. The National Meteorological Center ceased issuing warnings for it at 00 UTC on July 28. After weakening into a tropical depression, Typhoon Gemi entered and affected Hunan Province. From 00 UTC on July 26 to 01 UTC on July 29, 2024, Chenzhou City, especially Zixing City, experienced extreme heavy rainfall that broke historical records, causing a major rainstorm disaster.

[0038] The tropical cyclone termination location identification module receives the optimal track data CH2024BST.txt for tropical cyclones. This data includes a header record and optimal track data records, with the formats of the two data sets respectively located in [the relevant files]. Figure 3 and Figure 4The header record includes the following: AAAAA classification marker, '66666' indicating optimal path data; BBBB, international code, the last two digits of the year followed by a two-digit code, such as 2403, which is the international code used in this patent implementation case; CCC, the number of rows of path data records; DDDD, the sequence number of tropical cyclones including tropical depressions; EEEE, my country's code for tropical cyclones; F, tropical cyclone termination record; G, the number of hours between each path row; H...H, the English name of the tropical cyclone; I...I, the date the dataset was created. The optimal path data for each time period includes the typhoon's location and intensity information, recorded in one line. The record includes the following information: time (YYYY year, MM month, DD day, HH hour (UTC)); typhoon intensity (I), with 1-6 representing the six typhoon levels (tropical depression, tropical storm, severe tropical storm, typhoon, severe typhoon, super typhoon); latitude of typhoon LAT; longitude of typhoon LONG; minimum air pressure near the typhoon center (PRES); maximum wind speed near the typhoon center (WND); and 2-minute average wind speed (OWD) (m / s). This patent implementation uses WND.

[0039] To obtain the location where Typhoon "Gemi" ceases tracking, since the last record in the best track data for Typhoon "Gemi" is below 10.8 m / s, the valid latitude and longitude coordinates of that record are used as the location where tracking ceases (refer to Table 1), which is (29.5°N, 114.2°E). At the same time, the time of cessation is recorded as 2024072800, which is July 28, 2024, 00UTC.

[0040] The stop identification and judgment module performs a judgment every 6 hours. The first judgment is performed using the 850 hPa reanalysis data of 06UTC on July 28, 2024. Within the region with the center of "Grim" (29.5°N, 114.2°E) at the previous time (00UTC on July 28, 2024) as the origin and a radius of 300 km: through the ERA5 reanalysis data, it is determined that there is a closed contour line with a geopotential height value ≤148 dagpm. Furthermore, the current time stream function extreme value is negative and the relative vorticity is positive when calculated using the 850 hPa wind field. Therefore, the remnant vortex identification module of the tropical cyclone is entered to determine the latitude and longitude position of the remnant vortex center of the tropical cyclone.

[0041] The tropical cyclone remnant vortex identification module uses 850 hPa data reanalyzed at 06 UTC on July 28, 2024. Within a 300 km radius region, with the center of Typhoon Gemi (29.5°N, 114.2°E) at the previous time (00 UTC on July 28, 2024) as the origin, the average position of the extreme coordinates of the stream function, relative vorticity, and geopotential height field on the isobaric surface is used as the location of the tropical cyclone remnant vortex center (refer to Table 2). The final result is (113.32°E, 27.83°N). This result is used as the new origin for stopping identification and remnant vortex identification at 12 UTC on July 28, and so on, until the module outputs "Yes". At 18:00 on July 29, ERA5 reanalysis data was used to determine that there were no closed contour lines with a geopotential height value ≤148 dagpm at 850hPa. Therefore, the determination was stopped, and the module for outputting the location of the remnant vortex of the tropical cyclone was executed. The output results, Table 3, show the identification results of the location of the remnant vortex center during Typhoon "Gemi" identified by this system, which are consistent with the actual situation.

[0042] Table 1. Example of optimal path data for Typhoon "Gemi"

[0043] Table 2. Identification results of the tropical cyclone remnant vortex identification module at 06:00 on July 28, 2024.

[0044] Table 3. Locations of the remnant vortex centers of the identified tropical cyclones during Typhoon "Gemi".

[0045] The present invention provides an objective positioning system for remnant vortices of tropical cyclones, which can quantitatively determine the existence and location of remnant vortices of tropical cyclones, thereby achieving objective positioning of remnant vortices of tropical cyclones.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An objective positioning system for the remnant vortex of a tropical cyclone, characterized in that, include: The module includes a tropical cyclone stop location identification module, a stop identification judgment module, a tropical cyclone residual vortex identification module, and a module for outputting the location of tropical cyclone residual vortex. Among them, the tropical cyclone discontinuation location identification module is used to access the cyclone path dataset, parse the historical path records of a single tropical cyclone, determine the discontinuation time and the discontinuation location corresponding to the discontinuation time, and transmit the discontinuation time and discontinuation location as the initial spatiotemporal reference to the discontinuation identification judgment module. The stop identification and judgment module is used to periodically call meteorological reanalysis data according to a preset time step starting from the end time of the tropical cyclone. At each time step, the search area is constructed based on the tropical cyclone center or remnant vortex center determined in the previous time step, and the remnant vortex is judged based on the preset meteorological field threshold parameters to determine whether the remnant vortex has dissipated. If the remnant vortex is determined to have dissipated, the module outputs a remnant vortex dissipation judgment command to the tropical cyclone remnant vortex location module. If the remnant vortex is determined to still exist, the tropical cyclone remnant vortex identification module is triggered. The tropical cyclone remnant vortex identification module is used to calculate the remnant vortex center position at the current time step within the search area, and to pass the center position to the stop identification judgment module as the benchmark for constructing the search area at the next time step. The module for outputting the location of the residual vortex of a tropical cyclone is used to integrate and output the trajectory data of the residual vortex center position changing over time from the time the tropical cyclone ceases to the time the residual vortex is determined to have dissipated.

2. The system according to claim 1, characterized in that, The tropical cyclone termination location identification module uses the tropical cyclone number as an index to analyze the corresponding path records in chronological order. When it is identified that the maximum wind speed near the center of the tropical cyclone drops to or below the preset threshold for the first time, the time corresponding to that time is determined as the termination time, and the latitude and longitude coordinates corresponding to that time are determined as the termination location.

3. The system according to claim 2, characterized in that, The preset threshold is 10.8 m / s. When the maximum wind speed near the center of a tropical cyclone is detected to drop below 10.8 m / s for the first time, and the maximum wind speed near the center of the tropical cyclone does not recover to 10.8 m / s or above in subsequent observation times, the time corresponding to that time is determined as the stop time, and the latitude and longitude coordinates corresponding to that time are determined as the stop position.

4. The system according to claim 1, characterized in that, The stopping identification and judgment module determines the persistence of residual vortices within the search area based on preset meteorological field threshold parameters, including: judgment based on geopotential height field, stream function field, and relative vorticity field. The residual vortex is determined to have disappeared when any of the following conditions are met: There are no closed contour lines with potential height values ​​less than or equal to the preset threshold within the search area; or The current time step flow function has a positive extremum; or The relative vorticity extremum at the current time step is negative.

5. The system according to claim 4, characterized in that, The stop identification and judgment module extracts the geopotential height field and wind field from the 850hPa isobaric surface layer based on ERA5 reanalysis data, and calculates the stream function field based on the wind field to extract the relative vorticity field.

6. The system according to claim 4 or 5, characterized in that, The threshold for determining the closed contour line of the potential height is 148 dagpm.

7. The system according to claim 1, 5, or 6, characterized in that, The stop identification and judgment module constructs a circular search area with a radius of 300 km, centered on the stop position or the residual vortex center position of the previous moment. At each time step after the stop, ERA5 reanalysis data is called sequentially according to the 6-hour time step for judgment.

8. The system according to claim 1, characterized in that, Within the same search area as the stop identification module, the tropical cyclone remnant vortex identification module determines the minimum point of the geopotential height field, the maximum point of the relative vorticity field, and the minimum point of the stream function field, respectively, and determines the location of the remnant vortex center at the current time step based on the three extreme points.

9. The system according to claim 8, characterized in that, When calculating the location of the residual vortex center, the tropical cyclone remnant vortex identification module converts the latitude and longitude coordinates of the three extreme points into three-dimensional rectangular coordinates, averages the converted three-dimensional coordinates, and then back-calculates them into latitude and longitude coordinates. The back-calculated latitude and longitude coordinates are used as the location of the residual vortex center.

10. The system according to claim 1, characterized in that, The trajectory data from the tropical cyclone remnant vortex location module is integrated and output, including: The residual vortex data at each time point are used to generate a basic positioning dataset containing time, longitude coordinate fields, and latitude coordinate fields; The system associates and stores the extreme parameter fields of the stream function, relative vorticity, and geopotential height with each time period. Mark the residual vortex data after the stop time with a termination identifier and generate a termination report file containing complete meteorological elements.

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