Method, device, equipment and storage medium for analyzing tropical cyclone symmetry structure

Abstract

The present invention discloses a method, apparatus, device, and storage medium for analyzing the symmetry structure of a tropical cyclone. The method obtains hourly tropical cyclone center positions and intensity values from a tropical cyclone's optimal path data set, creates a polar coordinate system with the tropical cyclone center position as the origin, obtains hourly infrared cloud top brightness temperature data for the tropical cyclone, and interpolates the infrared cloud top brightness temperature data into a polar coordinate grid of the corresponding polar coordinate system using an interpolation method to obtain infrared cloud top brightness temperature polar coordinate grid data. The method then calculates convective symmetry index parameters for a preset inner core region of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data, and finally analyzes the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclone. The present invention defines the convective symmetry index of the inner core of the cyclone based on the infrared cloud top brightness temperature data of the tropical cyclone, and explores its relationship with changes in cyclone intensity, so as to explore the application of the index in tropical cyclone intensity forecasting.

Description

Technical Field

[0001] The present application relates to the field of meteorological analysis technology, and in particular to a method, device, equipment and storage medium for analyzing the symmetric structure of a tropical cyclone. Background Art

[0002] Tropical cyclones are among the most complex weather systems in the atmosphere, encompassing thermal and dynamic processes at multiple scales, as well as interactions between these scales. Advances in observational methods, particularly the use of unconventional observational data such as satellite radar, have significantly improved the accuracy of tropical cyclone track forecasts. However, progress in tropical cyclone intensity and structure forecasts remains slow. In coastal areas, with economic development, the losses caused by tropical cyclones are also increasing. Therefore, accurate tropical cyclone intensity forecasts are essential for tropical cyclone disaster prevention and mitigation. Forecasting tropical cyclone intensity has always been a difficult issue, and the rapid intensification of tropical cyclones, in particular, exacerbates this difficulty and presents a significant challenge.

[0003] For decades, many scholars have devoted themselves to the study of the evolution mechanism of tropical cyclones. Studies have found that when the large-scale environment is conducive to the development of tropical cyclone intensity, changes in the inner core structure of the tropical cyclone itself play an important role in rapid intensification. Further exploration of the inner core structure and evolution characteristics of rapidly intensified tropical cyclones is very necessary for the forecast of rapid intensification of tropical cyclones. The results of research on the mechanism of tropical cyclone intensification show that the release of latent heat of condensation of water vapor in convective activities is considered to be the main source of energy for the development and maintenance of secondary circulation in tropical cyclones. However, this organized severe convective activity often appears in an asymmetric form in the tropical cyclone circulation, and this asymmetry is particularly evident in the early stages of tropical cyclone development and the weakening stage. Therefore, studying the relationship between the asymmetric characteristics of tropical cyclones and the changes in tropical cyclone intensity is of great research significance for improving the asymmetric intensification mechanism of tropical cyclones.

[0004] At present, the research on the asymmetric characteristics of tropical cyclones mainly includes the following studies: (1) The asymmetric distribution of convection of tropical cyclones landing on the coast of South China was studied using GMS-5 satellite and radar data; (2) The probability density curve of the frequency of convection in tropical cyclones in the northwest Pacific is approximately a sine function along the azimuth angle, with obvious one-wave characteristics. Therefore, many studies have carried out Fourier expansion of the TBB field along the azimuth angle and characterized the degree of convection asymmetry by calculating the one-wave asymmetry value; (3) In the prediction model of rapid intensification of tropical cyclones in the Atlantic and northeastern Pacific, the percentage of infrared cloud top brightness temperatures below 30 degrees Celsius (PX30) within a radius of 50-200 kilometers and the standard deviation of infrared cloud top brightness temperatures (SDBT) in the same area are used as predictors of the convective symmetry around the center of the tropical cyclone. However, among the three methods mentioned above, the first method only conducts comparative analysis on the asymmetric distribution of convection in different quadrants of typical tropical cyclones, and it is difficult to form a consistent measurement index for the asymmetric distribution of all tropical cyclones; the second method uses the maximum amplitude of a wave of asymmetric values to represent the uniformity of convection distribution, and tends to study the asymmetric characteristics of convection in the spiral rain belt area outside tropical cyclones; the third method is easily affected by the interference of extreme brightness temperature values and produces large fluctuations. Summary of the Invention

[0005] In view of this, the present invention provides a method, device, equipment and storage medium for analyzing the symmetry structure of tropical cyclones, defines the index parameters of the convective symmetry of the inner core region of a tropical cyclone, and analyzes the relationship between the convective symmetry index parameters of the inner core of a tropical cyclone and the evolution of tropical cyclone intensity.

[0006] To solve the above technical problems, a technical solution adopted in the present application is: to provide a method for analyzing the symmetry structure of tropical cyclones, the method comprising: obtaining an optimal path data set of multiple tropical cyclones within a preset time period, and obtaining hourly tropical cyclone center positions and intensity values based on the optimal path data set; creating a corresponding polar coordinate system with the tropical cyclone center position as the origin; obtaining hourly infrared cloud top brightness temperature data of tropical cyclones, and interpolating the infrared cloud top brightness temperature data into the polar coordinate grid of the corresponding polar coordinate system based on the time correspondence to obtain infrared cloud top brightness temperature polar coordinate grid data; calculating the convective symmetry index parameters of a preset inner core area of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data; and analyzing the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones.

[0007] As a further improvement of the present application, the convective symmetry index parameters of the preset inner core area of the tropical cyclone are calculated based on the infrared cloud top brightness temperature polar coordinate grid data, including: calculating the 10% quantile and 90% quantile of the infrared cloud top brightness temperature polar coordinate grid data of the preset inner core area of the tropical cyclone; and calculating the convective symmetry index parameters of the tropical cyclone based on the difference between the 10% quantile and the 90% quantile.

[0008] As a further improvement of the present application, the calculation formula of the convective symmetry index parameter is expressed as: SymmetricRatio=1-(90%TBB-10%TBB) / maximum(90%TBB-10%TBB); wherein, SymmetricRatio represents the convective symmetry index parameter, TBB represents the polar coordinate grid data of infrared cloud top brightness temperature, and maximum(90%TBB-10%TBB) represents the preset climate value.

[0009] As a further improvement of the present application, the infrared cloud top brightness temperature data is interpolated into the polar coordinate grid of the corresponding polar coordinate system based on the time correspondence to obtain the infrared cloud top brightness temperature polar coordinate grid data, including: confirming the target polar coordinate grid points of each polar coordinate system with an interval of 4km in the radius r direction and an interval of 5° in the azimuth θ direction; based on the time correspondence, the infrared cloud top brightness temperature data is interpolated into the target polar coordinate grid points of the corresponding polar coordinate system by the interpolation method to obtain the infrared cloud top brightness temperature polar coordinate grid data.

[0010] As a further improvement of the present application, the preset inner core area of the tropical cyclone includes a circular area between a first preset radius and a second preset radius with the center of the tropical cyclone as the center, and the first preset radius is smaller than the second preset radius.

[0011] As a further improvement of the present application, the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of tropical cyclones is analyzed, including: comparative analysis of the first feature of the convective symmetry index in the rapid intensification stage and the non-rapid intensification stage of tropical cyclones, and constructing a first box plot for analysis, the rapid intensification stage and the non-rapid intensification stage are determined according to the magnitude of the continuously increasing wind speed of the maximum surface wind within a preset time period; comparative analysis of the second feature of the convective symmetry index in the rapid intensification stage of tropical cyclones of different grades, and constructing a second box plot for analysis, the grade of the tropical cyclone is determined according to the magnitude of the maximum wind speed near the center of the tropical cyclone; comparative analysis of the third feature of the convective symmetry index parameters of the rapid intensification stage of tropical cyclones changing with time, and constructing a third box plot for analysis.

[0012] As a further improvement of the present application, a convective symmetry index parameter is added as a prediction factor to the tropical cyclone intensity prediction model.

[0013] To solve the above technical problems, another technical solution adopted in the present application is: to provide a tropical cyclone symmetry structure analysis device, the device comprising: a first acquisition module, used to obtain the best path data set of multiple tropical cyclones within a preset time period, and obtain the hourly tropical cyclone position and intensity values based on the best path data set; a creation module, used to create a corresponding polar coordinate system with the center position of the tropical cyclone as the origin; a second acquisition module, used to obtain the hourly infrared cloud top brightness temperature data of the tropical cyclone, and based on the time correspondence, interpolate the infrared cloud top brightness temperature data into the polar coordinate grid of the polar coordinate system of the corresponding tropical cyclone by interpolation method to obtain infrared cloud top brightness temperature polar coordinate grid data; a calculation module, used to calculate the convective symmetry index parameters of the preset inner core area of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data; and an analysis module, used to analyze the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclone.

[0014] In order to solve the above technical problems, another technical solution adopted in this application is: to provide a computer device, which includes a processor and a memory coupled to the processor, wherein program instructions are stored in the memory, and when the program instructions are executed by the processor, the processor executes the steps of the tropical cyclone symmetry structure analysis method as described in any one of the above items.

[0015] In order to solve the above technical problems, another technical solution adopted in this application is: providing a storage medium storing program instructions capable of implementing any of the above tropical cyclone symmetry structure analysis methods.

[0016] The beneficial effects of the present application are as follows: the tropical cyclone symmetry structure analysis method of the present application confirms the hourly tropical cyclone position and intensity values based on the optimal path data set of the tropical cyclone, and creates a polar coordinate system with the tropical cyclone center position as the origin, and then obtains the hourly infrared cloud top brightness temperature data of the tropical cyclone, inserts the infrared cloud top brightness temperature data into the polar coordinate grid according to the temporal correspondence, obtains the infrared cloud top brightness temperature polar coordinate grid data, and then defines the convective symmetry index parameters of the tropical cyclone inner core area with the infrared cloud top brightness temperature polar coordinate grid data, and finally analyzes the relationship between the convective symmetry index parameters of the tropical cyclone and the intensity of the tropical cyclone, so that researchers can explore the application of the convective symmetry index in tropical cyclone intensity forecasting on this basis. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a flow chart of a method for analyzing the symmetric structure of a tropical cyclone according to an embodiment of the present invention;

[0018] Figure 2It is a statistical box plot of the convective symmetry index of tropical cyclones in the northwest Pacific during the rapid intensification (RI) stage and the non-rapid intensification (No-RI) stage;

[0019] Figure 3 It is a statistical box plot of the convective symmetry index of the rapid intensification of tropical cyclones of different grades in the Northwest Pacific from 2009 to 2021;

[0020] Figure 4 It is a statistical box plot of the temporal variation of convective symmetry indices during the rapid intensification of tropical cyclones;

[0021] Figure 5 1 is a schematic diagram of the functional modules of a tropical cyclone symmetry structure analysis device according to an embodiment of the present invention;

[0022] Figure 6 is a schematic structural diagram of a computer device according to an embodiment of the present invention;

[0023] Figure 7 It is a schematic structural diagram of a storage medium according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] The terms "first," "second," and "third" in this application are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this application, "multiple" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional indications in the embodiments of this application (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship, movement, etc. between the components under a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications also change accordingly. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0026] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] Figure 1 : is a flow chart of a method for analyzing the symmetric structure of a tropical cyclone according to an embodiment of the present invention. It should be noted that the method of the present invention is not limited to the method of the embodiment of the present invention if the results are substantially the same. Figure 1 The process sequence shown is limited. Figure 1 As shown, the tropical cyclone symmetry structure analysis method includes the following steps:

[0028] Step S101: obtaining optimal path data sets of multiple tropical cyclones within a preset time period, and obtaining hourly tropical cyclone center positions and intensity values based on the optimal path data sets.

[0029] It should be noted that the best track data sets (elements of which are tropical cyclone best track records) for the Northwest Pacific (or the Atlantic and Indian Oceans, etc.) can be downloaded from the official websites of the Shanghai Typhoon Research Institute, the Joint Typhoon Warning Center of the United States, the Japan Meteorological Agency, etc. for many years. Each tropical cyclone best track data set contains the longitude and latitude position and intensity of the tropical cyclone center for every 6 hours from the formation to the extinction of the tropical cyclone. This embodiment assumes that the tropical cyclone is moving at a constant speed and is evenly strengthening (or weakening) during the two recording times. The hourly tropical cyclone center position and intensity values can be obtained through linear interpolation.

[0030] Step S102: creating a corresponding polar coordinate system with the center of the tropical cyclone as the origin.

[0031] Step S103: Obtain hourly infrared cloud top brightness temperature data of tropical cyclones during the study period, and interpolate the infrared cloud top brightness temperature data into the corresponding polar coordinate grid using the RBF interpolation method based on the time correspondence to obtain polar coordinate grid data of infrared cloud top brightness temperature.

[0032] It should be noted that, since the satellite observation range can cover most of the ocean surface area, it makes up for the lack of atmospheric detection capabilities over the ocean to a large extent, providing more abundant remote sensing data for tropical cyclone research, and the infrared cloud top brightness temperature has a good correspondence with strong convection and precipitation caused by convection, so it can better indicate the strength of convection. The lower the brightness temperature value, the higher the cloud top extension height and the more vigorous the convection. Generally speaking, whether in the atmosphere or in the ocean, the faster the vortex rotates, the better its symmetry. Even if asymmetric rapidly intensifying tropical cyclones are in a moderate shear environment, they are accompanied by strong convective cyclonic rotation during the rapid intensification process, which makes the tropical cyclone structure tend to be symmetrical in the later stage of rapid intensification. Therefore, this embodiment uses the brightness temperature value of the long-wave infrared channel of the FY-2 series satellites to analyze the asymmetric structural characteristics of the convection in the inner core of the tropical cyclone.

[0033] Specifically, this embodiment downloads hourly Fengyun-2 full-disk nominal image files and their latitude and longitude comparison tables during tropical cyclone periods from the Fengyun satellite remote sensing data service website, then processes the downloaded data to obtain brightness temperature values for the longwave infrared channel (wavelength range: 10.3-11.3 μm). The hourly brightness temperature values for the longwave infrared channel are then interpolated into a corresponding polar coordinate grid based on a temporal correspondence. Specifically, the infrared cloud top brightness temperature data is interpolated into the corresponding tropical cyclone polar coordinate system based on the temporal correspondence to obtain the infrared cloud top brightness temperature coordinate data, specifically comprising the following steps:

[0034] 1. Confirm the target polar coordinate grid points of each polar coordinate system with a radius r direction interval of 4 km and an azimuth angle θ direction interval of 5°.

[0035] 2. Based on the time correspondence, the infrared cloud top brightness temperature data is interpolated into the target polar coordinate grid points of the corresponding polar coordinate system by interpolation method to obtain the infrared cloud top brightness temperature polar coordinate grid data.

[0036] Step S104: Calculating convective symmetry index parameters of a preset inner core region of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data.

[0037] It should be noted that the tropical cyclone convective activity studied in this embodiment is limited to the preset inner core area of the tropical cyclone. Generally, the inner core area of a tropical cyclone is defined as: an area within a radius of 1° with the center of the tropical cyclone as the center of the circle (the tropical and subtropical regions are approximately within a radius of 100km). However, in satellite cloud maps with obvious tropical cyclone eyes, downward airflow prevails in the eye of the tropical cyclone, and the brightness temperature value is relatively large. In order to eliminate the interference of the tropical cyclone eye area, this embodiment sets the preset inner core area of the tropical cyclone to a circular area between the first preset radius and the second preset radius with the center of the tropical cyclone as the center of the circle, and the first preset radius is smaller than the second preset radius. Preferably, in this embodiment, the first preset radius is preferably 50km, and the second preset radius is preferably 100km.

[0038] Furthermore, step S104 specifically includes:

[0039] 1. Calculate the 10% and 90% quantiles of the polar coordinate grid data of infrared cloud top brightness temperature in the predefined inner core region of a tropical cyclone.

[0040] 2. Calculate the convective symmetry index parameters of tropical cyclones by combining the difference between the 10% quantile and the 90% quantile.

[0041] Among them, the calculation formula of the convection symmetry index parameter is expressed as:

[0042] Symmetric Ratio=1-(90%TBB-10%TBB) / maximum(90%TBB-10%TBB);

[0043] Among them, Symmetric Ratio represents the convective symmetry index parameter, TBB represents the polar coordinate grid data of infrared cloud top brightness temperature, and maximum (90% TBB-10% TBB) represents the preset climate value. This embodiment is based on the tropical cyclones in the northwest Pacific from 2009 to 2021, so the preset climate value is set to 105.

[0044] Step S105: Analyze the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones.

[0045] Specifically, after obtaining the convective symmetry index parameters of all tropical cyclones, an analysis is conducted in combination with the intensity change process of tropical cyclones.

[0046] Furthermore, step S105 specifically includes:

[0047] 1. Compare and analyze the first characteristic of the convective symmetry index during the rapid intensification stage and the non-rapid intensification stage of a tropical cyclone, and construct the first box plot for analysis. The rapid intensification stage and the non-rapid intensification stage are determined by the magnitude of the maximum surface wind speed that continues to increase within a preset time period.

[0048] It should be noted that the most commonly used criterion for determining the rapid intensification of a tropical cyclone is that the maximum surface wind continues to increase to 15m / s within 24 hours. However, studies have pointed out that the 24-hour criterion tends to favor the rapid intensification of tropical cyclones with central winds less than 33m / s, while for some tropical cyclones with intensities greater than 33m / s, when rapid intensification occurs, the structure with the maximum wind speed radius in a stable state may not be able to last for 24 hours. Therefore, they define the continuous increase of the maximum surface wind to 10m / s within 12 hours as a rapid intensification process. The present invention uses this standard to calculate the tropical cyclones that have undergone a rapid intensification process during the study period, which can be applied to the rapid changes of tropical cyclones with a larger intensity range.

[0049] Specifically, if Figure 2 As shown, Figure 2 The statistical box plots of convective symmetry indices of tropical cyclones in the Northwest Pacific during the rapid intensification (RI) and non-rapid intensification (No-RI) phases from 2009 to 2021 are shown. Figure 2 It can be seen that the median and minimum values of the convective symmetry index in the rapid intensification stage are greater than those in the non-rapid intensification stage, indicating that the better the symmetry of the tropical cyclone, the more likely it is to undergo rapid intensification.

[0050] 2. Compare and analyze the second characteristic of the convective symmetry index of the rapid intensification process of tropical cyclones of different levels, and construct a second box plot for analysis. The tropical cyclone level is determined by the maximum wind speed near the center of the tropical cyclone.

[0051] It should be noted that according to my country's national standard "Tropical Cyclone Scale" (GB / T19201-2006), the intensity levels corresponding to tropical cyclones are divided: the maximum wind speed near the center is 17.2-24.4m / s for tropical storm (TS), the maximum wind speed near the center is 24.5-32.6m / s for severe tropical storm (STS), the maximum wind speed near the center is 32.7-41.4m / s for typhoon (TY), the maximum wind speed near the center is 41.5-50.9m / s for strong typhoon (STY), and the maximum wind speed near the center is greater than 51.0m / s for super typhoon (SuperTY).

[0052] Specifically, if Figure 3 As shown, Figure 3 A statistical box plot shows the rapidly enhanced convective symmetry index of tropical cyclones of different levels in the northwest Pacific from 2009 to 2021. From the statistical results, it can be seen that the higher the level of the tropical cyclone, the larger the median and minimum value of its convective symmetry index, indicating that the convection in its inner core is also more compact and symmetrical.

[0053] 3. Compare and analyze the third characteristic of the temporal changes of the convective symmetry index parameters during the rapid intensification stage of tropical cyclones, and construct a third box plot for analysis.

[0054] Specifically, in order to analyze the changing characteristics of the convective symmetry index during the rapid intensification of tropical cyclones, the rapid intensification process was divided into four stages for statistical analysis. Figure 4 This is a statistical box plot of the temporal variation of convective symmetry indices during the rapid intensification of tropical cyclones. Figure 4 It can be seen that during the rapid intensification of tropical cyclones, the median of their symmetry index gradually increases with time, indicating that the convection in the inner core of tropical cyclones tends to be more symmetrical during the rapid intensification process.

[0055] Furthermore, the convective symmetry index parameter is used to add to the tropical cyclone intensity prediction model.

[0056] This embodiment obtains the hourly center position of the tropical cyclone based on the optimal path data of the tropical cyclone, creates a polar coordinate system with the center position of the tropical cyclone as the origin, then obtains the hourly infrared cloud top brightness temperature data of the tropical cyclone, interpolates the infrared cloud top brightness temperature data into the polar coordinate grid points according to the temporal correspondence, and obtains the infrared cloud top brightness temperature polar coordinate grid data. The infrared cloud top brightness temperature polar coordinate grid data is then used to define the convective symmetry index parameters of the tropical cyclone inner core area. Finally, the relationship between the index parameters and the intensity of the tropical cyclone is analyzed, accurately reflecting the changing characteristics of the convective symmetry of the inner core of the tropical cyclone during the intensity change of the tropical cyclone, so that researchers can explore the application of the convective symmetry index in the tropical cyclone intensity forecast on this basis.

[0057] Figure 5 FIG. 1 is a schematic diagram of the functional modules of the tropical cyclone symmetry structure analysis device according to an embodiment of the present invention. Figure 5 As shown, the tropical cyclone symmetry structure analysis device 20 includes a first acquisition module 21 , a creation module 22 , a second acquisition module 23 , a calculation module 24 and an analysis module 25 .

[0058] A first acquisition module 21 is configured to acquire optimal path datasets of multiple tropical cyclones within a preset time period, and acquire hourly tropical cyclone positions and intensity values based on the optimal path datasets;

[0059] A creation module 22 is used to create a corresponding polar coordinate system with the center position of the tropical cyclone as the origin;

[0060] The second acquisition module 23 is configured to obtain hourly infrared cloud top brightness temperature data of the tropical cyclone, and interpolate the infrared cloud top brightness temperature data into a polar coordinate grid of a polar coordinate system of the corresponding tropical cyclone based on a time correspondence, thereby obtaining infrared cloud top brightness temperature polar coordinate grid data;

[0061] A calculation module 24 is configured to calculate a convective symmetry index parameter of a preset inner core region of a tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data;

[0062] The analysis module 25 is used to analyze the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones.

[0063] Optionally, the calculation module 24 performs an operation of calculating the convective symmetry index parameters of the preset inner core area of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data, specifically including: calculating the 10% quantile and 90% quantile of the infrared cloud top brightness temperature polar coordinate grid data of the preset inner core area of the tropical cyclone; and calculating the convective symmetry index parameters of the tropical cyclone based on the difference between the 10% quantile and the 90% quantile.

[0064] Optionally, the calculation formula of the convection symmetry index parameter is expressed as:

[0065] Symmetric Ratio=1-(90%TBB-10%TBB) / maximum(90%TBB-10%TBB);

[0066] Among them, Symmetric Ratio represents the convective symmetry index parameter, TBB represents the infrared cloud top brightness temperature polar coordinate grid data, and maximum (90% TBB-10% TBB) represents the preset climate value.

[0067] Optionally, the second acquisition module 23 performs an operation of interpolating the infrared cloud top brightness temperature data into the polar coordinate grid of the corresponding polar coordinate system based on the time correspondence to obtain the infrared cloud top brightness temperature polar coordinate grid data, specifically including: confirming the target polar coordinate grid points of each polar coordinate system with a radius r direction interval of 4 km and an azimuth angle θ direction interval of 5°; interpolating the infrared cloud top brightness temperature data into the target polar coordinate grid points of the corresponding polar coordinate system based on the time correspondence to obtain the infrared cloud top brightness temperature polar coordinate grid data.

[0068] Optionally, the preset inner core area of the tropical cyclone includes a circular area between a first preset radius and a second preset radius with the center of the tropical cyclone as the center, and the first preset radius is smaller than the second preset radius.

[0069] Optionally, the analysis module 25 performs an operation of analyzing the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones, specifically including: comparing and analyzing the first feature of the convective symmetry index in the rapid intensification stage and the non-rapid intensification stage of the tropical cyclone, and constructing a first box plot for analysis, the rapid intensification stage and the non-rapid intensification stage are determined according to the magnitude of the continuously increasing wind speed of the maximum surface wind within a preset time period; comparing and analyzing the second feature of the convective symmetry index in the rapid intensification stage of tropical cyclones of different levels, and constructing a second box plot for analysis, the level of the tropical cyclone is determined according to the magnitude of the maximum wind speed near the center of the tropical cyclone; comparing and analyzing the third feature of the convective symmetry index parameters of the rapid intensification stage of the tropical cyclone over time, and constructing a third box plot for analysis.

[0070] Optionally, the convective symmetry index parameter is added as a prediction factor to the tropical cyclone intensity prediction model.

[0071] For other details about the technical solutions for implementing the modules in the tropical cyclone symmetry structure analysis device in the above embodiment, please refer to the description of the tropical cyclone symmetry structure analysis method in the above embodiment, which will not be repeated here.

[0072] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similarities between the various embodiments can be referred to in conjunction with each other. For device embodiments, since they are generally similar to method embodiments, their description is relatively simple, and for relevant details, reference can be made to the description of the method embodiments.

[0073] See also Figure 6 , Figure 6 FIG. 1 is a schematic diagram of the structure of a computer device according to an embodiment of the present invention. Figure 6 As shown, the computer device 30 includes a processor 31 and a memory 32 coupled to the processor 31. The memory 32 stores program instructions. When the program instructions are executed by the processor 31, the processor 31 executes the steps of the tropical cyclone symmetry structure analysis method described in any of the above embodiments.

[0074] The processor 31 may also be referred to as a CPU (Central Processing Unit). The processor 31 may be an integrated circuit chip having signal processing capabilities. The processor 31 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The general-purpose processor may be a microprocessor or any conventional processor.

[0075] See Figure 7 , Figure 7 Schematic diagram of the structure of the storage medium of the embodiment of the present invention. The storage medium of the embodiment of the present invention stores program instructions 41 that can implement the above-mentioned tropical cyclone symmetry structure analysis method, wherein the program instructions 41 can be stored in the above-mentioned storage medium in the form of a software product, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or a computer device such as a computer, a server, a mobile phone, or a tablet.

[0076] In the several embodiments provided in this application, it should be understood that the disclosed computer devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0077] In addition, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units. The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for analyzing the symmetric structure of a tropical cyclone, characterized in that: The method comprises: Obtaining optimal path data sets for multiple tropical cyclones within a preset time period, and obtaining hourly tropical cyclone center positions and intensity values based on the optimal path data sets; Create a corresponding polar coordinate system with the center of the tropical cyclone as the origin; Obtain hourly infrared cloud top brightness temperature data of the tropical cyclone, and interpolate the infrared cloud top brightness temperature data into a polar coordinate grid of a corresponding polar coordinate system based on a time correspondence to obtain infrared cloud top brightness temperature polar coordinate grid data; Calculating convective symmetry index parameters of a preset inner core region of a tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data; Analyze the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of tropical cyclones; among them: The calculating of the convective symmetry index parameter of the preset inner core region of the tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data includes: Calculate the 10% and 90% quantiles of the polar grid data of infrared cloud top brightness temperature in the pre-set inner core region of a tropical cyclone; Calculating a convective symmetry index parameter of the tropical cyclone based on the difference between the 10% quantile and the 90% quantile; The calculation formula of the convection symmetry index parameter is expressed as: Symmetric Ratio=1-(90%TBB-10%TBB) / maximum(90%TBB-10%TBB); Wherein, Symmetric Ratio represents the convective symmetry index parameter, TBB represents the infrared cloud top brightness temperature polar coordinate grid data, and maximum (90% TBB-10% TBB) represents the preset climate value.

2. The method for analyzing the symmetric structure of tropical cyclones according to claim 1, wherein: The method of interpolating the infrared cloud top brightness temperature data into a polar coordinate grid of a corresponding polar coordinate system based on the time correspondence to obtain the infrared cloud top brightness temperature polar coordinate grid data includes: Confirm the target polar coordinate grid points of each polar coordinate system with a radius r direction interval of 4 km and an azimuth angle θ direction interval of 5°; Based on the time correspondence, the infrared cloud top brightness temperature data is interpolated into the target polar coordinate grid points of the corresponding polar coordinate system by an interpolation method to obtain the infrared cloud top brightness temperature polar coordinate grid data.

3. The method for analyzing the symmetric structure of tropical cyclones according to claim 1, wherein: The preset inner core area of the tropical cyclone includes a circular area between a first preset radius and a second preset radius with the center of the tropical cyclone as the center, and the first preset radius is smaller than the second preset radius.

4. The method for analyzing the symmetric structure of tropical cyclones according to claim 1, wherein: The analysis of the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones includes: Comparing and analyzing the first characteristic of the convective symmetry index during the rapid intensification phase and the non-rapid intensification phase of a tropical cyclone, and constructing a first box plot for analysis, the rapid intensification phase and the non-rapid intensification phase being determined based on the magnitude of the maximum surface wind speed that continuously increases within a preset time period; Comparing and analyzing the second characteristic of the convective symmetry index during the rapid intensification phase of tropical cyclones of different grades, and constructing a second box plot for analysis, the grade of the tropical cyclone being determined according to the maximum wind speed near the center of the tropical cyclone; The third characteristic of the temporal variation of the convective symmetry index parameters during the rapid intensification phase of the tropical cyclone is compared and analyzed, and a third box plot is constructed for analysis.

5. The method for analyzing the symmetric structure of tropical cyclones according to claim 1, wherein: The convective symmetry index parameter is added as a prediction factor into the tropical cyclone intensity prediction model.

6. A tropical cyclone symmetry structure analysis device using the tropical cyclone symmetry structure analysis method according to claim 1, characterized in that: The device comprises: A first acquisition module is configured to acquire optimal path data sets of multiple tropical cyclones within a preset time period, and acquire hourly tropical cyclone position and intensity values based on the optimal path data sets; Create a module for creating a corresponding polar coordinate system with the center of the tropical cyclone as the origin; The second acquisition module is used to obtain hourly infrared cloud top brightness temperature data of the tropical cyclone, and interpolate the infrared cloud top brightness temperature data into the polar coordinate grid of the polar coordinate system of the corresponding tropical cyclone based on the time correspondence to obtain infrared cloud top brightness temperature polar coordinate grid data; A calculation module, configured to calculate convective symmetry index parameters of a preset inner core region of a tropical cyclone based on the infrared cloud top brightness temperature polar coordinate grid data; The analysis module is used to analyze the relationship between the convective symmetry index parameters of all tropical cyclones and the intensity of the tropical cyclones.

7. A computer device, characterized in that: The computer device includes a processor and a memory coupled to the processor, wherein program instructions are stored in the memory. When the program instructions are executed by the processor, the processor executes the steps of the tropical cyclone symmetry structure analysis method as described in any one of claims 1 to 5.

8. A storage medium, characterized in that: The device stores program instructions capable of implementing the tropical cyclone symmetry structure analysis method according to any one of claims 1 to 5.

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