Northeast cold vortex automatic identification method and system

Abstract

The invention discloses a northeast cold vortex automatic identification method and system, and the method comprises the steps: obtaining a height field, a wind field and a temperature field of a target region, and calculating the low-value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at a plurality of target moments; at each target moment, taking the low-value center of the height field as an original point, if a circulation center matched with the low-value center exists in the first monitoring area and a cold center matched with the low-value center exists in the second monitoring area, determining that the low-value center is a cold vortex center at the target moment; and carrying out center merging and horizontal tracking on the low-value centers of all target moments to obtain a final northeast cold vortex activity path. Therefore, according to the method and the system provided by the invention, the cold vortex center identified by the height field is used as the candidate cold vortex center point, and the accuracy of cold vortex center identification is improved by matching the circulation center identified by the wind field and the cold center identified by the temperature field.

Description

Technical Field

[0001] The invention relates to the technical field of meteorological identification, and in particular to a method and system for automatically identifying a northeastern cold vortex. Background Art

[0002] The Northeast Cold Vortex is a weather system unique to Northeast my country, also known as Northeast Low Pressure, Cut-off Low Pressure, etc. In meteorological forecasting business, the Northeast Cold Vortex is usually defined as a low-pressure circulation system with at least one closed contour line in the range of 35-60°N, 115-145°E on the 500hPa weather map, a cold center or an obvious cold trough. The Northeast Cold Vortex can not only cause persistent rainy and flooding, sudden severe convection and other weather in Northeast China, but also cause highly disastrous mesoscale convective systems (such as squall lines) in North China, Central China, East China, and even Northwest and Southwest China, thereby triggering heavy rain, short-term heavy precipitation, thunderstorms, hail, strong winds and other disastrous weather. Therefore, it is very important to accurately identify the Northeast Cold Vortex.

[0003] The accurate identification of the cold vortex is crucial for a deeper understanding of the characteristics and mechanism of the Northeast Cold Vortex. Inaccurate identification of the cold vortex center will further affect the accuracy of cold vortex path tracking. Although computer-assisted objective identification technology has made significant progress in recent years, existing methods still have shortcomings in accurately identifying the cold vortex center:

[0004] (1) The accuracy of cold vortex center identification: The current method mainly relies on whether the height value of the center point is lower than that of its surrounding area (for example, the 8-point method or the 24-point method). This method only uses the height field to judge the low-value center, ignoring the characteristics of the vortex closed circulation. It often leads to the omission of the real low-vortex center when the threshold setting based on the height field is strict. For example, the potential height of some cold vortex centers is equal to the value of the surrounding points; when the threshold setting is loose, a large number of false vortices may be generated, thereby reducing the accuracy of identification.

[0005] (2) Problems in judging the closed boundary of the cold vortex system: Existing mainstream vortex identification technologies usually provide the potential height and longitude and latitude position information of the low vortex center, but are insufficient in judging the closure of the cold vortex weather system. The commonly used method is to judge the closure by increasing the grid points in eight directions outward from the cold vortex center, but the accuracy of the boundaries identified by this method is not high. In addition, some technologies use a fixed potential height interval (such as 40 dagpm) to retrieve the vortex boundary. Since this interval is set relatively coarsely, the identified boundary lacks the necessary accuracy. In addition, since the search is performed outward from the low value center at the contour interval, it is also easy to cause deviations and waste of computing resources.

[0006] (3) The problem of the birth of low vortices: The existing cold vortex identification algorithm only retains the low values ​​of the potential height within the outermost contour area, ignoring the birth of low vortices and causing wrong judgments. Summary of the invention

[0007] To this end, an embodiment of the present invention provides a method and system for automatically identifying a northeastern cold vortex to solve at least one technical problem existing in the above-mentioned prior art.

[0008] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0009] The present invention provides a method for automatically identifying a northeastern cold vortex, the method comprising:

[0010] Obtain the height field, wind field and temperature field of the target area;

[0011] Calculating the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments;

[0012] At each target time, taking the low value center of the height field as the origin, if there is a circulation center matching the low value center in the first monitoring area, and there is a cold center matching the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target time;

[0013] The cold vortex centers at all target times are centrally merged and horizontally tracked to obtain the final activity path of the northeastern cold vortex.

[0014] In some embodiments, calculating the low value center of the height field specifically includes:

[0015] Constructing a plurality of grid systems on the height field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point;

[0016] If the potential height of the central grid point is lower than the potential height of all surrounding grid points, and the number of increasing grid points of the central grid point in N directions is greater than or equal to the preset number, and the potential height difference between the increasing grid points of the central grid point in M ​​directions and the central grid point is greater than or equal to the preset height difference, then the central grid point is determined to be a low-value center.

[0017] In some embodiments, calculating the circulation center of the wind field specifically includes:

[0018] Smoothing the wind field, and determining the cyclonic property of the smoothed wind field to obtain candidate points;

[0019] Taking the candidate point as the center, divide the quadrants into four and eight quadrants;

[0020] The low-vortex cyclonic wind field center is determined by pre-set quadrant average wind field limiting conditions and quadrant group counterclockwise rotation conditions, and the low-vortex cyclonic wind field center is used as the circulation center.

[0021] In some embodiments, calculating the cold center of the temperature field specifically includes:

[0022] Constructing a plurality of grid systems on the temperature field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point;

[0023] If the latitudinal second-order derivative of the air temperature of the central grid point and the adjacent surrounding grid points is greater than or equal to zero, the central grid point is determined to be the cold center of the temperature field.

[0024] In some embodiments, the first monitoring area is a square frame centered on the low value center and formed by 5° to the north, south, west and east, and the second monitoring area is a square frame centered on the low value center and formed by 10° to the north, south, west and east.

[0025] In some embodiments, determining the low value center as the cold vortex center at the target time further includes:

[0026] Take the center of the cold vortex at the target time as the center and round it up to get the center height of the northeastern cold vortex center;

[0027] Determine the cold vortex center as the center and the square frame consisting of 15° to the north, south, west and east as the cold vortex center monitoring area;

[0028] Get the maximum and minimum values ​​of the height field at the current moment, perform contour analysis at preset intervals, and arrange the contour values ​​in reverse order from large to small;

[0029] If the contour points of the contour line all fall within the monitoring area of ​​the cold vortex center, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further determines whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line.

[0030] Perform contour analysis on the outermost closed contour lines of the cold vortex, create a blank image of the size of the height field array, draw the outermost contour lines and fill them with colors, calculate the area and scale of the contour using the contour method, and extract the target cold vortex whose area and scale exceed the area threshold and scale threshold.

[0031] In some embodiments, extracting the target cold vortex further comprises:

[0032] Calculate the distance between adjacent moments of the target vortex;

[0033] If there are target cold vortices exceeding the preset number of cold vortices at the next moment that match the previous moment, they are matched according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices;

[0034] Limit the duration and origin of the cold vortex, and determine the cold vortex horizontal tracking data set, including time, longitude, latitude and duration;

[0035] According to the cold vortex horizontal tracking data set, the morphological characteristics of the target cold vortex at each moment are further output, including the major axis, minor axis, eccentricity, intensity, area, temperature and other characteristics of the ellipse.

[0036] The present invention also provides a Northeast cold vortex automatic identification system, the system comprising:

[0037] A data acquisition unit, used to acquire the height field, wind field and temperature field of the target area;

[0038] A cold vortex calculation unit, used to calculate the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments;

[0039] A center confirmation unit is used to determine, at each target time, the low value center of the height field as the origin, if there is a circulation center that matches the low value center in the first monitoring area, and there is a cold center that matches the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target time;

[0040] The center merging unit monitors whether there are multiple low-value centers within the range of 10 longitudes and latitudes. If so, the low value of the height field is selected for center merging to obtain the final northeastern cold vortex center;

[0041] The center tracking unit is used to horizontally track the cold vortex center at all target times, and to confirm the cold vortex activity path of the northeastern cold vortex center.

[0042] The present invention also provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the program.

[0043] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and the computer program implements the steps of the above method when executed by a processor.

[0044] The method and system for automatically identifying the Northeastern cold vortex provided by the present invention obtains the height field, wind field and temperature field of the target area, calculates the low-value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments; at each target moment, the low-value center of the height field is used as the origin, if there is a circulation center that matches the low-value center in the first monitoring area, and there is a cold center that matches the low-value center in the second monitoring area, then the low-value center is determined to be the cold vortex center at the target moment; the cold vortex centers at all target moments are centrally merged and horizontally tracked to obtain the final Northeastern cold vortex activity path. In this way, the method and system provided by the present invention use the cold vortex center identified by the height field as the candidate cold vortex center point, and improves the accuracy of cold vortex identification center identification by coordinating the circulation center identified by the wind field and the cold center identified by the temperature field.

[0045] Furthermore, in the automatic identification method of the northeastern cold vortex provided by the present invention, after determining that the low-value center is the cold vortex center, it also includes: taking the cold vortex center as the center and rounding up to obtain the central height of the northeastern cold vortex center; determining a square frame consisting of 15° to the north, south, west and east with the cold vortex center as the center as the cold vortex center monitoring area; obtaining the maximum and minimum values ​​of the height field at the current moment, performing contour line analysis at preset intervals, and arranging the contour line values ​​in reverse order from large to small; if the contour points of the contour lines all fall within the cold vortex center monitoring area, the contour line analysis is performed at preset intervals, and the contour line values ​​are arranged ... at preset intervals, the contour line analysis is performed at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, and the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset intervals, the contour line values ​​are arranged at preset interval In the measured area, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line; contour analysis is performed on the outermost closed contour line of the cold vortex, a blank image of the size of the height field array is created, the outermost contour line is drawn and filled with color, the contour method is used to calculate the area and scale of the contour, and the target cold vortex whose area and scale exceed the area threshold and scale threshold is extracted. In this way, the method provided by the present invention automatically identifies the outermost closed contour line through an image processing algorithm, determines the long axis and other scale information of the cold vortex through a contour method, and thus realizes accurate judgment of the closed boundary of the cold vortex system.

[0046] Furthermore, the method for automatically identifying the Northeastern cold vortex provided by the present invention further includes calculating the distance between adjacent moments of the target vortex after extracting the target cold vortex. If there are more than a preset number of target cold vortices at the next moment that match the previous moment, matching is performed according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices. In this way, when matching the low-vortex path, if there are multiple centers at a certain moment that meet the distance threshold with the cold vortex at the previous moment, the method provided by the present invention is first matched according to the principle of the closest distance, and the remaining vortices create new vortex paths as new vortices. Only when the distance difference between two low vortices is the same, the low value of the potential height is retained and the low vortex center with a high potential height is proposed. The path matching algorithm considering the new low vortex is more reasonable and more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0048] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0049] Figure 1 One of the flow charts of the method for automatically identifying the northeastern cold vortex provided by the present invention;

[0050] Figure 2 The second flowchart of the method for automatically identifying the northeastern cold vortex provided by the present invention;

[0051] Figure 3 The third flowchart of the method for automatically identifying the northeastern cold vortex provided by the present invention;

[0052] Figure 4 This is the fourth flow chart of the method for automatically identifying the northeastern cold vortex provided by the present invention;

[0053] Figure 5 This is a structural block diagram of the Northeast Cold Vortex Automatic Identification System provided by the present invention;

[0054] Figure 6 This is a structural block diagram of a computer device provided by the present invention. DETAILED DESCRIPTION

[0055] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] In order to solve the problems existing in the prior art, the present invention provides a method for automatically identifying the Northeast cold vortex. First, a center is selected in the height field, wind field and temperature field respectively to obtain the low center of the height field, the circulation center of the wind field and the cold center of the temperature field; then, taking the height as the center, the coordination of the surrounding circulation center and the cold center is checked; the cold vortex center at all times is identified; on this basis, the centers of the previous and next times are matched, and the cold vortex centers are connected according to the closest distance and the lowest height to determine the activity trajectory of the cold vortex center.

[0057] Combine the following Figure 1-Figure 5 The automatic identification method and system of the Northeastern cold vortex provided by the present invention are introduced.

[0058] Please refer to Figure 1 , Figure 1 This is one of the flow charts of the method for automatically identifying the northeastern cold vortex provided by the present invention.

[0059] In a specific embodiment, the method for automatically identifying the northeastern cold vortex provided by the present invention comprises the following steps:

[0060] S110: Obtain the height field, wind field and temperature field of the target area; that is, obtain the 500hPa height field, 500hPa wind field and 500hPa temperature field of the entire area or part of the area in Northeast China.

[0061] S120: Calculate the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments; that is, at each target moment, calculate its low value center based on the height field, calculate its circulation center based on the wind field, and calculate its cold center based on the temperature field, so as to provide data support for subsequent center integration. It should be understood that the target moment can be adjusted according to data with different time resolutions, such as tracking at 1h intervals, 3h intervals, and 6h intervals.

[0062] S130: At each target moment, taking the low value center of the height field as the origin, if there is a circulation center that matches the low value center in the first monitoring area, and there is a cold center that matches the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center of the target moment; generally, the first monitoring area is a square frame with the low value center as the center, and 5° to the north, south, west and east respectively, and the second monitoring area is a square frame with the low value center as the center, and 10° to the north, south, west and east respectively; in a specific usage scenario, based on the low value center identified by the height field, whether there is a circulation center (vortex center identified by the wind field) within 5 longitudes and latitudes to match it, and whether there is a cold center (cold center or cold trough identified by the temperature field) within 10 longitudes and latitudes to match it, it is determined to be the cold vortex center of the target moment.

[0063] S140: The cold vortex centers of all target moments are centrally merged and horizontally tracked to obtain the final activity path of the northeastern cold vortex; that is, the center merging is to merge the cold vortex centers of all identified target moments. For one moment, it is used to monitor whether there are multiple cold vortex centers within 10 longitudes and latitudes. If so, the low value of the height field is selected for center merging to obtain the final northeastern cold vortex center. After the merging, the subsequent activity trajectory is determined based on the distance threshold of adjacent moments.

[0064] It should be understood that the center, circulation center and cold center identified by the height field mentioned above all have a process of center merging during the determination process, which can be understood as selecting only one low center of height, the circulation center of the wind field, and the cold center of temperature within a range. Finally, based on the low center identified by the height field as the center, it is determined whether there are actually existing wind field centers and cold centers nearby, and finally the cold vortex center is determined. Among them, the relationship between the wind field circulation center and the cold vortex is often close, so the determination area is small, and the range of 5 longitudes and latitudes is selected from the east, west, south, and north. The requirements for the cold center are relatively low, so the determination range is enlarged, and the range of 10 longitudes and latitudes is selected from the east, west, south, and north.

[0065] In some embodiments, Figure 2 As shown, calculating the low value center of the height field specifically includes the following steps:

[0066] S210: construct multiple grid systems on the height field, each grid system includes a central grid point and surrounding grid points adjacent to the central grid point; in the field of meteorology, the points for constructing the grid system usually refer to the location of a meteorological station or the coordinates of a meteorological observation point, and meteorological data can be collected through ground meteorological stations, satellites, radars, aircraft or other meteorological observation equipment; each point in the grid system contains a series of meteorological data, such as temperature, air pressure, wind speed, wind direction, humidity, etc., and these data points constitute an irregular observation network covering the target area.

[0067] S220: If the potential height of the central grid point is lower than that of all surrounding grid points (K 2 -1) grid point potential height, and the number of increasing grid points of the central grid point in N (N≤8) directions is greater than or equal to the preset number, and the potential height difference between the increasing grid points of the central grid point in M ​​(M≤8) directions and the central grid point is greater than or equal to the preset height difference, then the central grid point is determined to be a low-value center.

[0068] The subsequent M and N are determined based on the eight directions divided around the low value center.

[0069] Theoretically, using 8 or 24 grid points to calculate the low-value center actually means using these points to build a finer grid to more accurately analyze the height field. The key to this method is how to use these points to estimate the position and intensity of the vortex. The specific number of grid points can be determined based on the actual data resolution used.

[0070] Specifically, in the process of identifying the low-value center of the 500hPa height field, if the 500hPa potential height of the central grid point is lower than that of the surrounding 8 adjacent grid points (taking the 8-point method as an example); the grid potential heights are all increasing from the center to the outside, and the number of increasing grid points in N directions is at least 3, satisfying N≥7; and the difference in potential height between the increasing grid points and the central grid point in M ​​directions exceeds 4dagpm, satisfying M≥6; it is limited to identifying at most one low-value center within the 5 longitudes and latitudes within the square frame centered on the low-value center, and the center with the lower potential height is selected.

[0071] In some embodiments, calculating the circulation center of the wind field specifically includes:

[0072] Smoothing the wind field, and determining the cyclonic property of the smoothed wind field to obtain candidate points;

[0073] Taking the candidate point as the center, divide the quadrants into four and eight quadrants;

[0074] The low-vortex cyclonic wind field center is determined by pre-set quadrant average wind field limiting conditions and quadrant group counterclockwise rotation conditions, and the low-vortex cyclonic wind field center is used as the circulation center.

[0075] The pre-set quadrant average wind field limitation condition may be that, when the target area is divided into four quadrants, namely, the due east quadrant, the due north quadrant, the due west quadrant and the due south quadrant, if the average meridional wind in the due east quadrant is The average meridional wind in the due east quadrant satisfies the average wind field restriction condition of the quadrant; if the average zonal wind in the due north quadrant The average zonal wind in the due north quadrant satisfies the average wind field restriction condition of the quadrant; if the average meridional wind in the due west quadrant The meridional wind in the due west quadrant satisfies the average wind field limit condition of the quadrant; if the average zonal wind in the due south quadrant The meridional wind in the south quadrant satisfies the quadrant average wind field limitation condition; when the target area is divided into eight quadrants, namely, the first east quadrant, the second east quadrant, the first north quadrant, the second north quadrant, the first west quadrant, the second west quadrant, the first south quadrant and the second south quadrant, if the average meridional wind in the first east quadrant The average meridional wind in the first east quadrant satisfies the average wind field restriction condition of the quadrant; if the average meridional wind in the second east quadrant The average meridional wind in the second eastern quadrant satisfies the average wind field restriction condition of the quadrant; if the average zonal wind in the first northern quadrant The average zonal wind in the first northern quadrant satisfies the average wind field restriction condition of the quadrant; if the average zonal wind in the second northern quadrant The average zonal wind in the second northern quadrant satisfies the average wind field restriction condition of the quadrant; if the average meridional wind in the first western quadrant The average meridional wind in the first western quadrant satisfies the average wind field restriction condition of the quadrant; if the average meridional wind in the second western quadrant The average meridional wind in the second western quadrant satisfies the average wind field restriction condition of the quadrant; if the average zonal wind in the first southern quadrant The average zonal wind in the first southern quadrant satisfies the average wind field restriction condition of the quadrant; if the average zonal wind in the second southern quadrant Then the average zonal wind in the second southern quadrant meets the quadrant average wind field limitation condition.

[0076] The counterclockwise rotation condition of the quadrant group sets the value range of the average wind direction to [-180°, 180°], and the direction deviation angle C(α, β) between the two average wind directions α, β is defined as: when the target area is divided into four quadrants, namely, the due east quadrant, the due north quadrant, the due west quadrant and the due south quadrant, the direction deviation angle of each quadrant group is determined. If the direction deviation angle of the quadrant group is between 0° and 180°, it is determined that the quadrant group satisfies the condition that the average wind direction of the quadrant group rotates counterclockwise; wherein, represents the average wind direction in the due east quadrant, represents the average wind direction in the north quadrant, represents the average wind direction in the due west quadrant, represents the average wind direction of the south quadrant; when the target area is divided into eight quadrants, namely, the first east quadrant, the second east quadrant, the first north quadrant, the second north quadrant, the first west quadrant, the second west quadrant, the first south quadrant and the second south quadrant, determine the direction deviation angle of each quadrant group; if the direction deviation angle of the quadrant group is between 0° and 180°, determine that the quadrant group satisfies the counterclockwise rotation condition of the average wind direction of the quadrant group; wherein, represents the average wind direction in the first east quadrant, represents the average wind direction of the second east quadrant, represents the average wind direction in the first northern quadrant, represents the average wind direction of the second northern quadrant, represents the average wind direction in the first western quadrant, represents the average wind direction in the second western quadrant, represents the average wind direction of the first southern quadrant, Indicates the average wind direction for the second south quadrant.

[0077] That is to say, in the process of identifying the cyclonic circulation center in the 500hPa wind field, the ERA5 wind field is smoothed at nine points, and the grid wind field cyclonicity is determined when the grid point's latitude wind is negative, the latitude wind is positive, the longitude wind is positive, and the longitude wind is negative, and the grid point wind field cyclonicity is determined to obtain candidate points; with the candidate points as the center, the four quadrants and eight quadrants are divided, and the low-vortex cyclonic wind field center is further determined by the quadrant average wind field restriction conditions and the counterclockwise rotation conditions of the quadrant group. N is the number of adjacent quadrants, N = 4 in the four quadrants; N = 7 in the eight quadrants; limit the five longitudes and latitudes in the square frame centered on the low-value center to identify at most one low-value center, and if there are multiple centers, take their average position.

[0078] In some embodiments, when calculating the cold center of the temperature field, the calculation is performed to satisfy the requirement that the latitudinal second-order derivative of the air temperature at the central grid point and the surrounding adjacent points is greater than zero (the latitudinal second-order derivative is the central difference). Specifically, the following steps are included:

[0079] Constructing a plurality of grid systems on the temperature field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point;

[0080] If the central grid point and the adjacent surrounding grid points (K 2 -1) is greater than or equal to zero. If it exists, the central grid point is determined to be a low-value center.

[0081] More specifically, the second-order derivatives are calculated: for the central grid point and its surrounding neighboring grid points ((K 2 -1)), calculate the latitudinal second-order derivative of temperature. In two-dimensional space, the latitudinal second-order derivative of temperature can be expressed as Where T is the temperature and x is the latitudinal position. The judgment condition is that if the latitudinal second-order derivative of the temperature at the central grid point and its surrounding grid points is greater than or equal to zero Then the condition of the low value center is met; this condition indicates that near the central grid point, the temperature distribution is convex upward, which is a characteristic of the cold vortex center.

[0082]

[0083] This expression represents the second-order partial derivative of temperature T with respect to latitudinal position x. At discrete data points, the second-order derivative can be approximated by the following difference formula:

[0084]

[0085] Among them, T(x+Δx) is the temperature value after moving one grid point east (or west, depending on the definition of the coordinate system) at position x; T(x) is the temperature value of the center grid point; T(x-Δx) is the temperature value after moving one grid point west (or east) at position x; Δx is the distance between grid points.

[0086] This difference formula is based on the central difference method, which assumes that the temperature field varies smoothly between grid points and can be approximated by a quadratic polynomial. The central difference method is usually more accurate than forward or backward differences because it considers the values ​​on both sides of the central point. In practical applications, this calculation may be performed on the output data of a meteorological model, which is usually given on a regular grid. When dealing with real data, it is necessary to pay attention to the resolution and grid spacing of the data, as well as possible boundary conditions.

[0087] Furthermore, if Figure 3As shown, the low value center is determined as the cold vortex center at the target time, and then the following steps are included:

[0088] S310: Taking the cold vortex center at the target time as the center and rounding up to obtain the center height of the northeastern cold vortex center;

[0089] S320: Determine a square frame with the cold vortex center as the center and 15° to the north, south, west and east as the cold vortex center monitoring area;

[0090] S330: Obtain the maximum and minimum values ​​of the height field at the current moment, perform contour analysis at preset intervals, and arrange the contour values ​​in reverse order from large to small;

[0091] S340: If all the contour points of the contour line fall within the monitoring area of ​​the cold vortex center, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line.

[0092] S350: Perform contour analysis on the outermost closed contour lines of the cold vortex, create a blank image of the size of the height field array, draw the outermost contour lines and fill them with colors, calculate the area and scale of the contour using the contour method, and extract the target cold vortex whose area and scale exceed the area threshold and scale threshold.

[0093] That is to say, in the contour analysis, the merged cold vortex center is taken as the center, and the cold vortex center height Z is rounded up to determine the 10° range in the east, west, south and north centered on the center height Z as the cold vortex center monitoring area. The maximum and minimum values ​​of the height field at the current moment are obtained, and the contour line analysis is performed at intervals of 1dagpm. The contour line values ​​are arranged in reverse order from large to small. If the contour points of the contour line all fall in the cold vortex center monitoring area, further determine whether the contour line is closed. Use image processing technology to detect whether the first point and the last point are connected end to end. If so, it is determined to be the outermost closed contour line of the cold vortex center.

[0094] Contour analysis is performed on the outermost closed contour lines of the cold vortex, a blank image of the size of the height field array is created, the outermost contour lines are drawn and filled with color, the contour method is used to further calculate the area and scale of the contour, and only the cold vortex area and scale exceeding the area threshold and scale threshold are retained for cold vortex path tracking. In this way, the method provided by the present invention automatically identifies the outermost closed contour lines through an image processing algorithm, and determines the long axis and other scale information of the cold vortex through a contour method, thereby achieving accurate judgment of the closed boundary of the cold vortex system. On the basis of the same system judgment, the closure judgment of the cold vortex boundary system is added. In addition to the requirement of being able to analyze at least one closed contour line, the outermost closed contour lines are automatically identified using image processing technology, and the long axis and other scale information of the cold vortex are determined through a contour method.

[0095] When using the contour method to calculate the area and size of a contour, specifically, if there is a closed contour, it can be regarded as a set of vertices that are connected in sequence to form a polygon. For such a polygon, Green's formula can be used to calculate its area by converting the boundary curve integral of the polygon into the integral of its internal area.

[0096] In the discrete case, for a point (x1, y1), (x2, y2), ..., (x n ,y n ) composed of polygons (contours), where (x n+1 ,y n+1 ) is equal to (x1,y1) (i.e. the contour is closed), the area A can be calculated by the following summation formula:

[0097]

[0098] Here (x i ,y i ) is the i-th vertex of the polygon, and (x i+1 ,y i+1 ) is the next vertex. This formula calculates the sum of the directed areas of the vectors between adjacent vertices, then adds them together and takes the absolute value. In OpenCV, the cv2.contourArea function can be directly applied to contours of any shape, whether convex or concave, because it handles the vertices of the contour through proper mathematical methods. For complex contours, more complex calculations are performed internally, but the basic principle is still based on the above integration and summation process.

[0099] Furthermore, the method for automatically identifying the northeastern cold vortex provided by the present invention further comprises, after extracting the target cold vortex:

[0100] Calculate the distance between adjacent moments of the target vortex;

[0101] If there are target cold vortices exceeding the preset number of cold vortices at the next moment that match the previous moment, they are matched according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices;

[0102] Limit the duration and origin of the cold vortex, and determine the cold vortex horizontal tracking data set, including time, longitude, latitude and duration;

[0103] According to the cold vortex horizontal tracking data set, the morphological characteristics of the target cold vortex at each moment are further output, including the major axis, minor axis, eccentricity, intensity, area, temperature and other characteristics of the ellipse.

[0104] In this way, the method provided by the present invention, when matching the low-vortex path, if there are multiple centers at a certain moment that meet the distance threshold with the cold vortex at the previous moment, first match them according to the principle of closest distance, and the remaining vortices create new vortex paths as new vortices. Only when the distance difference between two low vortices is the same, the low value of the potential height is retained and the low-vortex center with a high potential height is proposed. The path matching algorithm considering the new birth of the low vortex is more reasonable. When tracing the vortex path, the new birth of the low vortex is considered for path matching according to the principle of closest distance first and lowest potential height later, instead of merging multiple low vortices according to the outermost contour line with the lowest potential height, which has higher accuracy.

[0105] In actual use, when tracing the path, the cold vortex of the same nature at the previous and next moments is tracked to obtain the cold vortex path. The distance between adjacent vortices is calculated. If the longitude difference is less than 10° and the latitude difference is less than 6°, it is considered to be a vortex of the same nature and is matched. In particular, if there are more than two cold vortices matching the previous moment at the next moment, they are matched according to the principle of the closest distance and the lowest height, that is, first check whether all vortex core connections are the vortices closest to each other, and secondly, if the distance is equivalent, select the vortex with a lower center height for matching, and the remaining cold vortices establish a new cold vortex path for matching.

[0106] In a specific usage scenario, such as Figure 4As shown, the automatic identification method of the northeastern cold vortex provided by the present invention is specifically implemented by a center identification module and a path tracking module; wherein, the center identification module includes height field acquisition, wind field acquisition, temperature field acquisition and contour analysis. During the height field acquisition process, after obtaining the 500hPa height field, the central potential height is locally the lowest. When the potential heights in n directions increase outward and the difference in potential heights in m directions exceeds 4dagpm, the central point is determined to be a low-value center; after obtaining the 500hPa wind field, the grid wind field rotation is determined, and the four quadrants and eight quadrants are divided to meet the quadrant average wind field restriction conditions and the quadrant group average wind direction counterclockwise rotation conditions, thereby determining the circulation center according to the cyclonic circulation; after obtaining the 500hPa temperature field, cold center coordination is performed; area and scale analysis is performed through contour analysis, and finally center merging is performed. During the implementation of the path tracking module, the center data of the Northeast Cold Vortex after center merging is received, a new vortex path is established, and it is determined whether the vortex at the next time is within the distance threshold. If so, the vortex with the closest distance and the lowest height is matched, and then the next time is retrieved and the above judgment step is returned; if not, the vortex path tracking ends, and a new vortex path is constructed and the source and duration limits are set, and finally the Northeast Cold Vortex horizontal tracking data set is written.

[0107] In the above specific implementation, the method for automatically identifying the Northeast cold vortex provided by the present invention obtains the height field, wind field and temperature field of the target area, calculates the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field; takes the low value center of the height field as the origin, if there is a circulation center that matches the low value center in the first monitoring area, and there is a cold center that matches the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target time; the cold vortex centers at all target times are centrally merged and horizontally tracked to obtain the final Northeast cold vortex activity path. In this way, the method provided by the present invention uses the cold vortex center identified by the height field as the candidate cold vortex center point, and improves the accuracy of cold vortex identification center identification by coordinating the circulation center identified by the wind field and the cold center identified by the temperature field.

[0108] In addition to the above method, the present invention also provides a method system for automatically identifying the Northeast Cold Vortex, such as Figure 5 As shown, the system comprises:

[0109] A data acquisition unit 510 is used to acquire a height field, a wind field, and a temperature field of a target area;

[0110] A cold vortex calculation unit 520, used to calculate the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments;

[0111] The center confirmation unit 530 is used for, at each target time, taking the low value center of the height field as the origin, if there is a circulation center matching the low value center in the first monitoring area, and there is a cold center matching the low value center in the second monitoring area, then determining the low value center as the cold vortex center at the target time;

[0112] The center merging unit 540 is used to monitor whether there are multiple cold vortex centers within the range of 10 longitudes and latitudes. If there are, the low value of the height field is selected for center merging to obtain the final northeastern cold vortex center;

[0113] The center tracking unit 550 is used to horizontally track the cold vortex center at all target times to confirm the cold vortex activity path of the northeastern cold vortex center.

[0114] In some embodiments, calculating the low value center of the height field specifically includes:

[0115] Constructing a plurality of grid systems on the height field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point;

[0116] If the potential height of the central grid point is lower than the potential height of all surrounding grid points, and the number of increasing grid points of the central grid point in N directions is greater than or equal to the preset number, and the potential height difference between the increasing grid points of the central grid point in M ​​directions and the central grid point is greater than or equal to the preset height difference, then the central grid point is determined to be a low-value center.

[0117] In some embodiments, calculating the circulation center of the wind field specifically includes:

[0118] Smoothing the wind field, and determining the cyclonic property of the smoothed wind field to obtain candidate points;

[0119] Taking the candidate point as the center, divide the quadrants into four and eight quadrants;

[0120] The low-vortex cyclonic wind field center is determined by pre-set quadrant average wind field limiting conditions and quadrant group counterclockwise rotation conditions, and the low-vortex cyclonic wind field center is used as the circulation center.

[0121] In some embodiments, calculating the cold center of the temperature field specifically includes:

[0122] Constructing a plurality of grid systems on the temperature field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point;

[0123] If the latitudinal second-order derivative of the air temperature of the central grid point and the adjacent surrounding grid points is greater than or equal to zero, the central grid point is determined to be the cold center of the temperature field.

[0124] In some embodiments, the first monitoring area is a square frame centered on the low value center and formed by 5° to the north, south, west and east, and the second monitoring area is a square frame centered on the low value center and formed by 10° to the north, south, west and east.

[0125] In some embodiments, determining the low value center as the cold vortex center at the target time further includes:

[0126] Take the center of the cold vortex at the target time as the center and round it up to get the center height of the northeastern cold vortex center;

[0127] Determine the cold vortex center as the center and the square frame consisting of 15° to the north, south, west and east as the cold vortex center monitoring area;

[0128] Get the maximum and minimum values ​​of the height field at the current moment, perform contour analysis at preset intervals, and arrange the contour values ​​in reverse order from large to small;

[0129] If the contour points of the contour line all fall within the monitoring area of ​​the cold vortex center, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further determines whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line.

[0130] Perform contour analysis on the outermost closed contour lines of the cold vortex, create a blank image of the size of the height field array, draw the outermost contour lines and fill them with colors, calculate the area and scale of the contour using the contour method, and extract the target cold vortex whose area and scale exceed the area threshold and scale threshold.

[0131] In some embodiments, extracting the target cold vortex further comprises:

[0132] Calculate the distance between adjacent moments of the target vortex;

[0133] If there are target cold vortices exceeding the preset number of cold vortices at the next moment that match the previous moment, they are matched according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices;

[0134] Limit the duration and origin of the cold vortex, and determine the cold vortex horizontal tracking data set, including time, longitude, latitude and duration;

[0135] According to the cold vortex horizontal tracking data set, the morphological characteristics of the target cold vortex at each moment are further output, including the major axis, minor axis, eccentricity, intensity, area, temperature and other characteristics of the ellipse.

[0136] In the above specific implementation, the Northeastern cold vortex automatic identification system provided by the present invention obtains the height field, wind field and temperature field of the target area, calculates the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments; at each target moment, taking the low value center of the height field as the origin, if there is a circulation center that matches the low value center in the first monitoring area, and there is a cold center that matches the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target moment; the cold vortex centers at all target moments are centrally merged and horizontally tracked to obtain the final Northeastern cold vortex activity path. In this way, the system provided by the present invention uses the cold vortex center identified by the height field as the candidate cold vortex center point, and improves the accuracy of cold vortex identification center identification by coordinating the circulation center identified by the wind field and the cold center identified by the temperature field.

[0137] Furthermore, in the Northeastern cold vortex identification system provided by the present invention, the low-value center is determined to be the cold vortex center at the target time, and then the center height of the Northeastern cold vortex center is obtained by rounding up the cold vortex at the target time; a square frame consisting of 5° to the north, south, west and east with the cold vortex center as the center is determined as the cold vortex center monitoring area; the maximum and minimum values ​​of the height field at the current time are obtained, and contour line analysis is performed at preset intervals, and the contour line values ​​are arranged in reverse order from large to small; if the contour points of the contour lines all fall within the center of the cold vortex In the monitoring area, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further determines whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line; contour analysis is performed on the outermost closed contour line of the cold vortex, a blank image of the size of the height field array is created, the outermost contour line is drawn and filled with color, the contour area and scale are calculated using the contour method, and the target cold vortex whose area and scale exceed the area threshold and scale threshold is extracted. In this way, the method provided by the present invention automatically identifies the outermost closed contour line through an image processing algorithm, determines the long axis and other scale information of the cold vortex through the contour method, and thus realizes the accurate judgment of the closed boundary of the cold vortex system.

[0138] Furthermore, the Northeastern cold vortex identification system provided by the present invention further includes calculating the distance between adjacent target vortices after extracting the target cold vortex. If there are more than a preset number of target cold vortices at the next moment that match the previous moment, matching is performed according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices. In this way, when matching the low-vortex path, if the system provided by the present invention encounters a moment when there are multiple centers that meet the distance threshold with the cold vortex at the previous moment, matching is first performed according to the principle of the closest distance, and the remaining vortices create new vortex paths as new vortices. Only when the distance difference between two low vortices is the same, the low value of the potential height is retained and the low vortex center with a high potential height is proposed. The path matching algorithm considering the new low vortex is more reasonable and more accurate.

[0139] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 6 As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store static information and dynamic information data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps in the above method embodiment are implemented.

[0140] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0141] Corresponding to the above embodiment, the embodiment of the present invention further provides a computer storage medium, which contains one or more program instructions, wherein the one or more program instructions are used to execute the above method.

[0142] The present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the above method.

[0143] In the embodiment of the present invention, the processor may be an integrated circuit chip having the ability to process signals. The processor may 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 devices, discrete gate or transistor logic devices, or discrete hardware components.

[0144] The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present invention can be directly embodied as a hardware decoding processor for execution, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The processor reads the information in the storage medium and completes the steps of the above method in combination with its hardware.

[0145] The storage medium may be a memory, which may be, for example, a volatile memory or a nonvolatile memory, or may include both volatile and nonvolatile memory.

[0146] Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory.

[0147] The volatile memory may be a random access memory (RAM) which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct Rambus RAM (DRRAM).

[0148] The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0149] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the present invention can be implemented using a combination of hardware and software. When software is used, the corresponding functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. Storage media can be any available media that can be accessed by general or special-purpose computers.

[0150] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for automatically identifying a northeastern cold vortex, characterized in that: The method comprises: Obtain the height field, wind field and temperature field of the target area; Calculating the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments; At each target time, taking the low value center of the height field as the origin, if there is a circulation center matching the low value center in the first monitoring area, and there is a cold center matching the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target time; The cold vortex centers at all target times are centrally merged and horizontally tracked to obtain the final activity path of the northeastern cold vortex.

2. The method for automatically identifying the Northeast cold vortex according to claim 1 is characterized in that: Calculate the low value center of the height field, specifically including: Constructing a plurality of grid systems on the height field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point; If the potential height of the central grid point is lower than the potential height of all surrounding grid points, and the number of increasing grid points of the central grid point in N directions is greater than or equal to the preset number, and the potential height difference between the increasing grid points of the central grid point in M ​​directions and the central grid point is greater than or equal to the preset height difference, then the central grid point is determined to be a low-value center.

3. The automatic identification method of the Northeast Cold Vortex according to claim 1 is characterized in that: Calculating the circulation center of the wind field specifically includes: Smoothing the wind field, and determining the cyclonic property of the smoothed wind field to obtain candidate points; Taking the candidate point as the center, divide the quadrants into four and eight quadrants; The low-vortex cyclonic wind field center is determined by pre-set quadrant average wind field limiting conditions and quadrant group counterclockwise rotation conditions, and the low-vortex cyclonic wind field center is used as the circulation center.

4. The method for automatically identifying the Northeast cold vortex according to claim 1 is characterized in that: Calculating the cold center of the temperature field specifically includes: Constructing a plurality of grid systems on the temperature field, each grid system comprising a central grid point and surrounding grid points adjacent to the central grid point; If the latitudinal second-order derivative of the air temperature of the central grid point and the adjacent surrounding grid points is greater than or equal to zero, the central grid point is determined to be the cold center of the temperature field.

5. The method for automatically identifying the Northeast cold vortex according to claim 1 is characterized in that: The first monitoring area is a square frame centered on the low value center and formed by 5° to the north, south, west and east. The second monitoring area is a square frame centered on the low value center and formed by 10° to the north, south, west and east.

6. The method for automatically identifying the northeastern cold vortex according to any one of claims 1 to 5, characterized in that: Determine the low value center as the cold vortex center at the target time, and then include: Take the center of the cold vortex at the target time as the center and round it up to get the center height of the cold vortex center; Determine the cold vortex center as the center and the square frame consisting of 15° to the north, south, west and east as the cold vortex center monitoring area; Get the maximum and minimum values ​​of the height field at the current moment, perform contour analysis at preset intervals, and arrange the contour values ​​in reverse order from large to small; If the contour points of the contour line all fall within the monitoring area of ​​the cold vortex center, an image processing algorithm is used to detect whether the first point and the last point of the contour line are connected end to end. If so, it is determined to be a closed contour line of the cold vortex center, and further determines whether the low vortex center is within the closed contour line. If so, it is the outermost closed contour line. Perform contour analysis on the outermost closed contour lines of the cold vortex, create a blank image of the size of the height field array, draw the outermost contour lines and fill them with colors, calculate the area and scale of the contour using the contour method, and extract the target cold vortex whose area and scale exceed the area threshold and scale threshold.

7. The method for automatically identifying the Northeast cold vortex according to claim 6 is characterized in that: Extracting the target cold vortex, and then further comprising: Calculate the distance between adjacent moments of the target vortex; If there are target cold vortices exceeding the preset number of cold vortices at the next moment that match the previous moment, they are matched according to the principle of the closest distance and the lowest height, and a new cold vortex path is established for the remaining target cold vortices; Limit the duration and origin of the cold vortex, and determine the cold vortex horizontal tracking data set, including time, longitude, latitude and duration; According to the cold vortex horizontal tracking data set, the morphological characteristics of the target cold vortex at each moment are further output, including the major axis, minor axis, eccentricity, intensity, area, temperature and other characteristics of the ellipse.

8. A Northeast Cold Vortex Automatic Identification System, characterized in that: The system comprises: A data acquisition unit, used to acquire the height field, wind field and temperature field of the target area; A cold vortex calculation unit, used to calculate the low value center of the height field, the circulation center of the wind field, and the cold center of the temperature field at multiple target moments; A center confirmation unit is used to determine, at each target time, the low value center of the height field as the origin, if there is a circulation center that matches the low value center in the first monitoring area, and there is a cold center that matches the low value center in the second monitoring area, then the low value center is determined to be the cold vortex center at the target time; The center merging unit is used to monitor whether there are multiple cold vortex centers within the range of 10 longitudes and latitudes. If so, the low value of the height field is selected for center merging, and the low value center is used to obtain the final northeastern cold vortex center; The center tracking unit is used to horizontally track the cold vortex center at all target times, and to confirm the cold vortex activity path of the northeastern cold vortex center.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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