Long-time intensity maintenance type typhoon quantitative judgment method based on typhoon generalized maximum intensity

Abstract

The invention discloses a long-time intensity maintenance type typhoon quantitative judgment method based on typhoon generalized maximum intensity, and belongs to the technical field of meteorological science. The method mainly comprises the following steps: constructing a long-time intensity maintenance type typhoon judgment method for representing typhoon intensity by using the maximum wind speed, and constructing a long-time intensity maintenance type typhoon judgment method for representing typhoon intensity by using the central minimum air pressure. The invention provides two methods for judging the long-time intensity maintenance type typhoon based on the maximum wind speed and the minimum air pressure of the typhoon respectively, and two quantitative criteria of the long-time intensity maintenance type typhoon are given: in the aspect of disaster-causing property, the maximum intensity of the typhoon needs to be higher than that of strong typhoon, namely, the maximum wind speed is larger than or equal to 41 m / s; and in the rare aspect, the generalized maximum strength maintaining time of typhoon needs to reach 54 hours or above.

Description

Technical Field

[0001] The present invention belongs to the field of meteorological science and technology, and in particular relates to a quantitative judgment method for a long-term intensity-maintaining typhoon based on the generalized maximum intensity of the typhoon. Background Art

[0002] Analyzing the best path data of tropical cyclones, the results show that when the intensity of a typhoon is characterized by the lowest air pressure (maximum wind speed) at the center of the typhoon, its intensity changes over time in three typical types.

[0003] The first is the U-shape (inverted U-shape), that is, the typhoon intensity reaches above the strong typhoon standard, with a strong disaster-causing capacity, and it remains stable for a certain period of time at the maximum intensity stage before weakening. The time series of its intensity continuity is U-shaped (inverted U-shaped).

[0004] The second is the V-shape (inverted V-shape), that is, the typhoon intensity increases rapidly over time and then weakens rapidly. For example, Super Typhoon Meranti No. 1614, the maximum wind speed in the center reached 75m / s and then weakened rapidly. The maximum wind speed showed an inverted V-shape over time. Although it lasted for as long as 78 hours at the strong typhoon level or above, it did not maintain a relatively fixed intensity, so it does not belong to the U-shape with long-term intensity maintenance.

[0005] The third is the weak U-type (weak inverted U-type), that is, although the typhoon intensity change type is similar to the U-type (inverted U-type), due to insufficient conditions for the development of the typhoon, its intensity has been maintained below the strong typhoon level, and the disaster is relatively small, so it is called a weak U-type (inverted weak U-type).

[0006] Therefore, there are two main factors to consider when defining a typhoon that maintains intensity for a long time: one is the catastrophic nature, that is, the maximum intensity of the typhoon must reach a certain level; the other is the rarity, that is, the typhoon must maintain maximum intensity for a certain period of time. Then, the key issues in defining this type of typhoon can be attributed to the determination of the typhoon intensity level standard, the calculation method of the maintenance time, and the determination of the maintenance time standard. Summary of the invention

[0007] In view of the above-mentioned technical status, the present invention comprehensively considers the evolution characteristics of typhoons with long-term sustained intensity and the significant individual differences in typhoon intensity changes, and proposes a quantitative judgment scheme for typhoons with long-term sustained intensity based on the generalized maximum intensity of typhoons.

[0008] The present invention firstly conducts a statistical analysis on the occurrence probabilities of tropical depressions, tropical storms, severe tropical storms, typhoons, severe typhoons and super typhoons in recent years, and selects typhoon cases according to a determined disaster standard; then, based on a statistical analysis of the maximum intensity maintenance time and the occurrence probability of the selected typhoon cases, a quantitative judgment method for long-term intensity maintenance type typhoons is proposed.

[0009] The first aspect of the present invention discloses a quantitative judgment method for a long-term intensity-maintaining typhoon based on the generalized maximum intensity of the typhoon, the method comprising: judging a long-term intensity-maintaining typhoon by characterizing the typhoon intensity with the maximum wind speed; wherein:

[0010] Step 1: Define the broad range of typhoon maximum wind speed;

[0011] Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a;

[0012] Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers;

[0013] Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon;

[0014] Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons;

[0015] Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

[0016] According to the method of the first aspect of the present invention, the maximum wind speed interval is [V max_bot , V max_top ];in:

[0017] V max_bot =V max -V max ×a

[0018] V max_top =V max

[0019] a=δV / V max_mean

[0020] Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

[0021] According to the method of the first aspect of the present invention, the method further comprises: judging a typhoon of long-term intensity maintenance by characterizing the typhoon intensity with the lowest central air pressure; wherein:

[0022] Step 1: Define the broad minimum pressure range of typhoons;

[0023] Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b;

[0024] Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers;

[0025] Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon;

[0026] Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

[0027] According to the method of the first aspect of the present invention, the minimum air pressure interval is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which:

[0028] P min_bot =P min

[0029] P min_top =P min +(1013-P min )×b

[0030] Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

[0031] The second aspect of the present invention discloses a quantitative judgment system for a long-term intensity-maintained typhoon based on the generalized maximum intensity of the typhoon, the system comprising a processing unit, the processing unit being configured to: judge a long-term intensity-maintained typhoon characterized by the maximum wind speed; specifically comprising the following steps:

[0032] Step 1: Define the broad range of typhoon maximum wind speed;

[0033] Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a;

[0034] Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers;

[0035] Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon;

[0036] Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons;

[0037] Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

[0038] According to the system of the second aspect of the present invention, the maximum wind speed interval is [V max_bot , V max_top ];in:

[0039] V max_bot =V max -V max ×a

[0040] V max_top =V max

[0041] a=δV / V max_mean

[0042] Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

[0043] According to the system of the second aspect of the present invention, the processing unit is further configured to: determine a typhoon of long-term intensity maintenance type characterized by the central minimum air pressure; specifically comprising the following steps:

[0044] Step 1: Define the broad minimum pressure range of typhoons;

[0045] Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b;

[0046] Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers;

[0047] Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon;

[0048] Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

[0049] According to the system of the second aspect of the present invention, the minimum air pressure interval is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which:

[0050] P min_bot =P min

[0051] P min_top =P min +(1013-P min )×b

[0052] Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

[0053] The third aspect of the present invention discloses an electronic device. The electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method for quantitatively judging a long-term intensity-maintaining typhoon based on the generalized maximum intensity of a typhoon described in the first aspect of the present disclosure is implemented.

[0054] The fourth aspect of the present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the quantitative determination method of a long-term intensity-maintaining typhoon based on the generalized maximum intensity of a typhoon as described in the first aspect of the present disclosure.

[0055] In summary, the present invention proposes a method for judging a typhoon with long-term intensity maintenance based on the maximum wind speed and the minimum air pressure of the typhoon. The above judgment methods have their own characteristics for screening typhoons with long-term intensity maintenance. In terms of the severity of the criteria, for strong typhoons with low central minimum air pressure, the typhoon maximum wind speed definition criteria will be more stringent than the typhoon minimum air pressure, that is, the calculated maximum intensity maintenance time will be shorter; from the statistical proportion, the typhoons defined by the maximum wind speed of the typhoon are slightly more frequent with a duration of less than 18 hours, while the number of typhoons with a duration of 24-48 hours is relatively small, but the maintenance time corresponding to 90% of the cumulative frequency of maintenance time calculated by the two methods is 54 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 :This is a flow chart for judging a typhoon that maintains intensity for a long time, which uses the maximum wind speed to characterize the typhoon’s intensity;

[0058] Figure 2 :This is a flow chart for judging a typhoon that maintains intensity for a long time, using the lowest central pressure to characterize the intensity of the typhoon;

[0059] Figure 3 :(a) is a statistical chart of the maximum value (m / s) of the central maximum wind speed of tropical cyclones of strong typhoon level and above from 1979 to 2021, and (b) is a chart of the cumulative percentage of durations reaching the wind speed threshold;

[0060] Figure 4 :(a) is the minimum value (hPa) of the central minimum pressure of tropical cyclones of severe typhoon level and above from 1979 to 2021, (b) is the cumulative percentage diagram of the duration of reaching the pressure threshold;

[0061] Figure 5 It is the time variation curve of the central minimum pressure (blue line) and the central maximum wind speed (red line) of some long-term intensity-maintaining typhoons; among them, the pink and green dots respectively represent the times when the maximum wind speed or the minimum pressure in the center of the typhoon meets the intensity maintenance threshold conditions; ac is the case diagram with consistent results using wind speed and pressure criteria, df is the case diagram that meets the conditions only according to the wind speed criterion definition, and gi is the case diagram that meets the conditions only according to the pressure criterion definition. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative work are within the scope of protection of the present invention.

[0063] The first aspect of the present invention discloses a quantitative judgment method for a long-term intensity-maintaining typhoon based on the generalized maximum intensity of the typhoon, the method comprising: judging a long-term intensity-maintaining typhoon by characterizing the typhoon intensity with the maximum wind speed; wherein (e.g. Figure 1 shown):

[0064] Step 1: Define the broad range of typhoon maximum wind speed;

[0065] Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a;

[0066] Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers;

[0067] Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon;

[0068] Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons;

[0069] Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

[0070] According to the method of the first aspect of the present invention, the maximum wind speed interval is [V max_bot , V max_top ];in:

[0071] V max_bot =V max -V max ×a

[0072] V max_top =V max

[0073] a=δV / V max_mean

[0074] Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

[0075] According to the method of the first aspect of the present invention, the method further comprises: determining a typhoon of long-term intensity maintenance using the lowest central air pressure to characterize the typhoon intensity; wherein (such as Figure 2 shown):

[0076] Step 1: Define the broad minimum pressure range of typhoons;

[0077] Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b;

[0078] Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers;

[0079] Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon;

[0080] Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

[0081] According to the method of the first aspect of the present invention, the minimum air pressure interval is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which:

[0082] P min_bot =P min

[0083] P min_top =P min +(1013-P min )×b

[0084] Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

[0085] First embodiment

[0086] A method for judging a typhoon with long-term intensity maintenance based on the maximum wind speed and minimum air pressure of the typhoon, comprising: constructing a method for judging a typhoon with long-term intensity maintenance using the maximum wind speed to characterize the typhoon's intensity, and constructing a method for judging a typhoon with long-term intensity maintenance using the minimum central air pressure to characterize the typhoon's intensity.

[0087] The construction of a long-term intensity-maintaining typhoon judgment method characterized by maximum wind speed includes the following steps:

[0088] Step 1: First, define the generalized maximum wind speed of a typhoon as an interval, that is, [V max_bot ,V max_top ].

[0089] Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity. Based on these data, determine the typhoon maximum wind speed gradient coefficient a.

[0090] Step 3: Using the determined gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers.

[0091] Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the above-defined range, that is, the intensity maintenance time of the typhoon.

[0092] Step 5: Conduct a statistical analysis of the duration of intensity maintenance of all typhoons to determine statistical data such as the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons.

[0093] Step 6: Based on the results of statistical analysis, formulate the criteria for judging long-term intensity-maintaining typhoons. For example, a threshold value (such as 48 hours or 54 hours) can be set, and typhoons exceeding this threshold value can be judged as long-term intensity-maintaining typhoons.

[0094] In the process of constructing a long-term intensity-maintaining typhoon judgment method that uses maximum wind speed to characterize typhoon intensity, the present invention first defines the broad maximum wind speed of a typhoon as a maximum wind speed interval. max , then the maximum wind speed interval is [V max_bot ,V max_top ],in:

[0095] V max_bot =V max -V max ×a

[0096] V max_top =V max

[0097] a=δV / V max_mean

[0098] a is the typhoon maximum wind speed gradient coefficient, δV is the typhoon maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon. The duration during which the maximum wind speed of the typhoon is within this threshold range is counted as the intensity maintenance time of the typhoon. The stronger the typhoon, the wider the range of wind speed conditions for maintaining its maximum intensity.

[0099] Determining the generalized maximum wind speed of a typhoon is a prerequisite for calculating the time a strong typhoon can maintain at its maximum intensity, and the key to determining the generalized maximum wind speed of a typhoon is to obtain the typhoon maximum wind speed gradient coefficient a. Figure 3(a) is a statistical analysis of the number of maximum wind speeds of strong typhoons ranging from 42 to 80 m / s from 1979 to 2021. The results show that the largest number is 45 m / s, reaching nearly 100, followed by 50 m / s (85), 55 m / s (65), 60 m / s (60), and 65 m / s (25). The remaining intensities are all below 20. For the convenience of analysis, the five levels of typhoon cases, namely 45m / s (100), 50m / s (85), 55m / s (65), 60m / s (60), and 65m / s (25), are used as the analysis samples. The gradient of the maximum wind speed of the typhoon is 5m / s. The total number of samples is 335. The typhoon intensity corresponding to the median is taken as the average maximum typhoon intensity of the sample set, that is, the 170th corresponds to 50m / s. Therefore, the maximum wind speed gradient coefficient a of the typhoon is 0.1. In addition, since the central maximum wind speed observations near the peak of the typhoon intensity in the best path data set are discontinuous, mostly at intervals of 3m / s or 5m / s, even if the maximum wind speed gradient coefficient a of the typhoon is slightly adjusted around 0.1, it will not have a significant impact on the statistical results of the duration of the maximum intensity of the typhoon.

[0100] When the typhoon maximum wind speed gradient coefficient a is 0.1, the maximum wind speed interval corresponding to the central maximum wind speed of 45m / s is [40.5,45](m / s), and the interval width is 4.5m / s; the maximum wind speed interval corresponding to the central maximum wind speed of 80m / s is [72,80](m / s), and the interval width is 8m / s. It can be seen that the stronger the typhoon, the wider the range of wind speed conditions for maintaining its maximum intensity. The maintenance time of all typhoons in the maximum intensity interval was calculated and statistically analyzed. The results show that more than half of the strong typhoons maintained their maximum intensity for less than 20 hours, and there were 59 strong typhoons with maximum intensity lasting for more than 54 hours, of which the longest duration reached 168h. Judging from the cumulative percentage of the maximum intensity maintenance time ( Figure 3 (b)), strong typhoons that maintain their maximum intensity for 48 hours account for the 85.5th percentile, and strong typhoons that last for 54 hours account for the 89.5th percentile.

[0101] Second embodiment

[0102] A method for judging a typhoon with long-term intensity maintenance based on the maximum wind speed and minimum air pressure of the typhoon, comprising: constructing a method for judging a typhoon with long-term intensity maintenance using the maximum wind speed to characterize the typhoon's intensity, and constructing a method for judging a typhoon with long-term intensity maintenance using the minimum central air pressure to characterize the typhoon's intensity.

[0103] The construction of a long-term intensity-maintaining typhoon judgment method using the lowest central air pressure to characterize the typhoon intensity includes the following steps:

[0104] Step 1: First, define a generalized typhoon minimum pressure range, namely [P min_bot ,P min_top ].

[0105] Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data. Use the median and acceptable range of the lowest pressure to calculate the coefficient of deviation b.

[0106] Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers.

[0107] Step 4: For each typhoon, calculate the duration that its minimum air pressure is within the above-defined range, that is, the intensity maintenance time of the typhoon.

[0108] Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons, and formulate criteria for judging long-term intensity maintenance typhoons based on the results of the statistical analysis. For example, a threshold value (such as 48 hours or 54 hours) can be set, and typhoons exceeding this threshold value can be judged as long-term intensity maintenance typhoons.

[0109] In the process of constructing a long-term intensity-maintaining typhoon judgment method that uses the lowest central pressure to characterize the typhoon intensity, the present invention first defines the generalized lowest typhoon pressure as a lowest pressure interval. If the minimum value of the lowest central pressure of a typhoon is P min , then 1013-P min It can represent the deviation of the typhoon center pressure relative to the atmospheric pressure. The lowest pressure range is: [P min_bot ,P min_top ], that is, the duration of the typhoon's lowest air pressure within the threshold range is counted as the typhoon's intensity maintenance time, and their expression is:

[0110] P min_bot =P min

[0111] P min_top =P min +(1013-P min )×b

[0112] Where b is the typhoon minimum pressure deviation coefficient, the generalized typhoon minimum pressure P min_top The definition is different from the generalized maximum wind speed V of a typhoon. max_botThat is, a certain proportion of the deviation value is used instead of the proportion of the minimum air pressure itself. This is mainly because the minimum values ​​of the minimum air pressure in the centers of different typhoons vary greatly. The use of deviation values ​​will make the conditions for weaker (stronger) typhoons to maintain their intensity more stringent (loose), thereby avoiding the intensity maintenance time being too long due to a large range of air pressure values ​​included in the maintenance time.

[0113] Similarly, the key to determining the generalized typhoon minimum pressure is to obtain the typhoon minimum pressure deviation coefficient b. Figure 4 As shown in (a), the average value of the lowest pressure in the center of a strong typhoon is about 934hPa, and its range is 965-870hPa, with a median of 939hPa. When the acceptable fluctuation range of the lowest pressure in the center of a typhoon is 10hPa, the median of the lowest pressure is used to calculate the deviation coefficient b:

[0114]

[0115] By this calculation, the minimum central pressure of 870hPa corresponds to a minimum pressure change interval of [870,889.31](hPa), with an interval width of 19.31hPa; the maximum central pressure of 965hPa corresponds to a minimum pressure change interval of [965,971.48](hPa), with an interval width of 6.48hPa. Calculating the duration of all typhoons within the maximum intensity interval, it can be seen that there are 66 typhoons of the strong typhoon level or above with a maximum intensity of more than 48 hours, and 53 typhoons with a maximum intensity of more than 54 hours, of which the longest duration is 144 hours. Judging from the cumulative percentage of the maximum intensity maintenance time ( Figure 4 (b)), the strong typhoons that maintained their maximum intensity for 48 hours accounted for the 86.9th percentile, and the strong typhoons that lasted for 54 hours accounted for the 89.9th percentile.

[0116] In summary Figure 3 and Figure 4 It can be seen that the duration of typhoon intensity maintenance and the cumulative percentage distribution obtained by the above two calculation methods are not completely consistent. The results show that the number of typhoons defined by the maximum wind speed as the criterion is slightly higher than that of typhoons lasting less than 18 hours, and the number of typhoons lasting 24-48 hours is lower, while the number of typhoons lasting more than 54 hours defined by the two methods gradually tends to be consistent, and the cumulative frequency is close to 90%. The maximum duration of typhoon intensity defined by wind speed (168 hours) is greater than that defined by air pressure (144 hours).

[0117] Using the above two calculation methods, we can find 71 cases of strong typhoons whose intensity lasted for more than 54 hours (see Table 1). They can be roughly divided into three categories according to the criteria they meet:

[0118] ① There are 48 typhoons that meet both the minimum air pressure and maximum wind speed as criteria. Figure 5 As shown in (a)-(c), typhoons with long-term intensity maintenance do not decay rapidly after reaching their maximum intensity, but maintain their intensity for a long time. For example, Typhoon MANGKHUT in 2018 has been maintaining its intensity steadily after reaching its maximum intensity ( Figure 5 (c)). Since the wind speed and air pressure conditions for a typhoon to reach its intensity have a certain range, it is allowed that the minimum air pressure or maximum wind speed at the center of a typhoon will fluctuate after reaching its maximum intensity, such as JOAN in 1997 and Fengshen in 2002. Figure 5 (a)(b)).

[0119] ② There are 11 typhoons that only meet the maximum wind speed as the criterion. Figure 5 As shown in (d)-(f), there are two main reasons why the wind speed criterion meets the conditions but the pressure criterion does not. First, for strong typhoons with high central minimum pressure, the minimum pressure range is small and the conditions are relatively harsh, which makes the maximum intensity calculated according to the pressure criterion maintain for a short time, such as Man-Yi in 2018 and In-fa in 2021. Figure 5 (d), (f)); secondly, the typhoon's central minimum pressure fluctuates greatly during the period of maintaining maximum intensity, causing the intensity to be maintained intermittently, such as Dianmu in 2004 ( Figure 5 (e)).

[0120] ③ There are 12 typhoons that only meet the minimum air pressure as the criterion. Figure 5 As shown in (g)-(i), there are two main reasons why the wind speed criterion is not satisfied while the pressure criterion is satisfied. First, some typhoons do have a gentle change in the central minimum pressure during their strongest stage, but the temporal evolution of their central maximum wind speed is not a typical "U-shaped" distribution, such as Gay in 1981 and REX in 1998. Figure 5 (g) and (h); secondly, for strong typhoons with low central minimum pressure, the minimum pressure range is large and the wind speed criterion is relatively loose, so the maximum intensity calculated based on the pressure criterion lasts longer, such as Elsie in 1981 ( Figure 5 (i)).

[0121] In summary, the criteria of using the maximum wind speed and the minimum air pressure of a typhoon as calculation factors have their own characteristics for screening long-term intensity-maintaining typhoons, but the cumulative frequency of their maintenance time corresponding to 90% maintenance time is 54 hours. Therefore, the two quantitative criteria for long-term intensity-maintaining typhoons are:

[0122] ① Disaster-causing: The maximum intensity of the typhoon reaches or exceeds that of a strong typhoon, that is, the maximum wind speed is ≥41m / s.

[0123] ② Rarity: A typhoon maintains its maximum intensity in a broad sense for more than 54 hours.

[0124] According to this criterion, 71 typhoon cases were screened, of which 11 only met the maximum wind speed as the criterion, 12 only met the minimum air pressure as the criterion, and 48 met all of them.

[0125] The second aspect of the present invention discloses a quantitative judgment system for a long-term intensity-maintained typhoon based on the generalized maximum intensity of the typhoon, the system comprising a processing unit, the processing unit being configured to: judge a long-term intensity-maintained typhoon characterized by the maximum wind speed; specifically comprising the following steps:

[0126] Step 1: Define the broad range of typhoon maximum wind speed;

[0127] Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a;

[0128] Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers;

[0129] Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon;

[0130] Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons;

[0131] Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

[0132] According to the system of the second aspect of the present invention, the maximum wind speed interval is [V max_bot , V max_top ];in:

[0133] V max_bot =V max -V max ×a

[0134] V max_top =V max

[0135] a=δV / V max_mean

[0136] Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_meanis the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

[0137] According to the system of the second aspect of the present invention, the processing unit is further configured to: determine a typhoon of long-term intensity maintenance type characterized by the central minimum air pressure; specifically comprising the following steps:

[0138] Step 1: Define the broad minimum pressure range of typhoons;

[0139] Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b;

[0140] Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers;

[0141] Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon;

[0142] Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

[0143] According to the system of the second aspect of the present invention, the minimum air pressure interval is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which:

[0144] P min_bot =P min

[0145] P min_top =P min +(1013-P min )×b

[0146] Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

[0147] The third aspect of the present invention discloses an electronic device. The electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method for quantitatively judging a long-term intensity-maintaining typhoon based on the generalized maximum intensity of a typhoon described in the first aspect of the present disclosure is implemented.

[0148] The fourth aspect of the present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the quantitative determination method of a long-term intensity-maintaining typhoon based on the generalized maximum intensity of a typhoon as described in the first aspect of the present disclosure.

[0149] In summary, the present invention proposes a method for judging a typhoon with long-term intensity maintenance based on the maximum wind speed and the minimum air pressure of the typhoon. The above judgment methods have their own characteristics for screening typhoons with long-term intensity maintenance. In terms of the severity of the criteria, for strong typhoons with low central minimum air pressure, the typhoon maximum wind speed definition criteria will be more stringent than the typhoon minimum air pressure, that is, the calculated maximum intensity maintenance time will be shorter; from the statistical proportion, the typhoons defined by the maximum wind speed of the typhoon are slightly more frequent with a duration of less than 18 hours, while the number of typhoons with a duration of 24-48 hours is relatively small, but the maintenance time corresponding to 90% of the cumulative frequency of maintenance time calculated by the two methods is 54 hours.

[0150] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-mentioned embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. A quantitative judgment method for a typhoon with long-term intensity maintenance based on the generalized maximum intensity of the typhoon, characterized in that: The method comprises: judging a typhoon of long-term intensity maintenance by characterizing the typhoon intensity with the maximum wind speed; wherein: Step 1: Define the broad range of typhoon maximum wind speed; Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a; Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers; Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon; Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons; Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

2. A quantitative determination method for a typhoon of long-term intensity maintenance type based on the generalized maximum intensity of a typhoon according to claim 1, characterized in that: The maximum wind speed range is [V max_bot , V max_top ];in: V max_bot =V max -V max ×a V max_top =V max a=δV / V max_mean Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

3. A quantitative determination method for a typhoon with long-term intensity maintenance based on the generalized maximum intensity of a typhoon according to claim 2, characterized in that: The method further includes: determining a typhoon of long-term intensity maintenance using the lowest central air pressure to characterize the typhoon intensity; wherein: Step 1: Define the broad minimum pressure range of typhoons; Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b; Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers; Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon; Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

4. The method for quantitatively judging a typhoon with long-term intensity maintenance based on the generalized maximum intensity of a typhoon according to claim 3, characterized in that: The lowest air pressure range is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which: P min_bot =P min P min_top =P min +(1013-P min )×b Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

5. A long-term intensity-maintaining typhoon quantitative judgment system based on the generalized maximum intensity of the typhoon, characterized in that: The system includes a processing unit, and the processing unit is configured to: determine a long-term intensity-maintaining typhoon by characterizing the typhoon intensity with a maximum wind speed; The specific steps include: Step 1: Define the broad range of typhoon maximum wind speed; Step 2: By statistically analyzing historical data, determine the maximum wind speed values ​​of the typhoons with the largest number, and calculate the typhoon intensity corresponding to the median as the average maximum intensity, and further determine the typhoon maximum wind speed gradient coefficient a; Step 3: Using the determined maximum wind speed gradient coefficient a and the average maximum intensity, calculate the maximum wind speed range corresponding to the maximum wind speed at different centers; Step 4: For each typhoon, calculate the duration that its maximum wind speed is within the maximum wind speed range as the intensity maintenance time of the typhoon; Step 5: Conduct statistical analysis on the duration of intensity maintenance of all typhoons to determine the duration of maximum intensity maintenance and the longest duration of more than half of the strong typhoons; Step 6: Based on the results of statistical analysis, determine the criteria for judging a typhoon that maintains intensity for a long time by setting a threshold.

6. A long-term intensity-maintaining typhoon quantitative judgment system based on the generalized maximum intensity of the typhoon according to claim 5, characterized in that: The maximum wind speed range is [V max_bot , V max_top ];in: V max_bot =V max -V max ×a V max_top =V max a=δV / V max_mean Among them, a is the maximum wind speed gradient coefficient, δV is the maximum wind speed change gradient of each typhoon level, V max_mean is the average maximum intensity of the typhoon, V max It is the maximum wind speed in the center of the typhoon.

7. A quantitative determination method for a typhoon of long-term intensity maintenance type based on the generalized maximum intensity of a typhoon according to claim 6, characterized in that: The processing unit is further configured to: determine a typhoon of long-term intensity maintenance using the lowest central air pressure to characterize the typhoon intensity; specifically comprising the following steps: Step 1: Define the broad minimum pressure range of typhoons; Step 2: Determine the median and range of the lowest pressure in the center of a strong typhoon by statistically analyzing historical data, and use the median and acceptable range of pressure to calculate the coefficient of deviation b; Step 3: According to the calculated deviation coefficient b, determine the minimum air pressure range corresponding to the minimum air pressure at different centers; Step 4: For each typhoon, calculate the duration of its lowest air pressure within the lowest air pressure interval as the intensity maintenance time of the typhoon; Step 5: Conduct a statistical analysis on the duration of intensity maintenance of all typhoons. Based on the results of the statistical analysis, determine the criteria for judging typhoons that maintain intensity for a long time by setting thresholds.

8. A long-term intensity-maintaining typhoon quantitative judgment system based on the generalized maximum intensity of the typhoon according to claim 37, characterized in that: The lowest air pressure range is [P min_bot , P min_top ], the duration of the typhoon's lowest air pressure within the lowest air pressure interval is taken as the typhoon's intensity maintenance time; among which: P min_bot =P min P min_top =P min +(1013-P min )×b Among them, b is the typhoon minimum pressure deviation coefficient, P min It is the minimum value of the lowest air pressure in the center of a typhoon.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, it implements the quantitative judgment method for a long-term intensity-maintaining typhoon based on the generalized maximum intensity of the typhoon as described in any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, it implements the method for quantitatively judging a long-term intensity-maintaining typhoon based on the generalized maximum intensity of the typhoon as described in any one of claims 1 to 4.

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