Tropical cyclone precipitation analysis method and device based on solar terminator dynamic mapping

Abstract

The invention relates to the related technical field of precipitation analysis, in particular to a tropical cyclone precipitation analysis method and device based on solar terminator dynamic mapping. According to the method, a sun tracking time frame is constructed, UTC moments of any longitude and latitude points in the world are converted into STT time coordinates, and then time sequence reconstruction and daily variation statistics are carried out on tropical cyclone path points and precipitation fields around the tropical cyclone path points. The method comprises the following specific steps: acquiring a high-resolution tropical cyclone path and rainfall data; converting the world time information into sun tracking time information; determining a mask area with the tropical cyclone track point as the center; extracting an effective precipitation grid in the mask area; and analyzing the data by taking time information during sun tracking as a label to obtain tropical cyclone precipitation daily change information. According to the method, the deviation caused by different longitudes and latitudes of a traditional time frame is overcome, and the daily variation rule of the tropical cyclone precipitation system can be disclosed under a unified sun tracking reference frame.

Description

Technical Field

[0001] The present application relates to the technical field related to precipitation analysis, and specifically to a method and device for tropical cyclone precipitation analysis based on dynamic mapping of the solar terminator. Background Art

[0002] Tropical cyclones (TCs) are among the most significant and severe weather systems affecting mid- and low-latitude regions worldwide. They are often accompanied by extreme hazards such as strong winds, heavy rainfall, and storm surges, severely threatening life, property, and ecosystem stability in coastal areas. In recent years, as discussions on the intensity and frequency of TCs in the context of global warming have deepened, their precipitation characteristics, particularly their diurnal variations, have become a key insight into their internal physical mechanisms and energy regulation processes.

[0003] Traditionally, the extraction of diurnal variations in precipitation is typically performed using Universal Time Coordinated (UTC) as a reference, or directly calculated using Local Standard Time (LST). However, due to the combined effects of the Earth's rotation and revolution, the apparent altitude and angle of incidence of the Sun at different latitudes and longitudes vary significantly with the seasons. LST or UTC often cannot synchronously reflect the direct driving effect of solar radiation on atmospheric convection processes. This is particularly true when analyzing tropical cyclone tracks spanning multiple latitudes and longitudes. Using legacy timeframes can easily obscure the true physical rhythms of diurnal convection variations, leading to biased interpretations of spatial evolution patterns. Summary of the Invention

[0004] In view of this, the embodiments of the present application are committed to providing a tropical cyclone precipitation analysis method and device based on dynamic mapping of the solar terminator, so as to conduct precipitation analysis more comprehensively and effectively and avoid deviations from spatial evolution laws.

[0005] This application provides a tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator, comprising: Acquire high-resolution tropical cyclone track and precipitation data; wherein the tropical cyclone track includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; Converting the universal time information of each path point in the tropical cyclone path into solar tracking time information; specifically, calculating the solar declination angle and the solar direct point based on the universal time information, and determining the solar tracking time information of each path point based on the relative relationship between the path point's position information, the solar declination angle, and the solar direct point; Based on the tropical cyclone path, determining a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset value as the radius; Extracting effective precipitation grids in the mask area based on the precipitation data, and determining precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; The data to be analyzed is analyzed using the sun tracking time information as a label to obtain the diurnal variation information of tropical cyclone precipitation.

[0006] In some embodiments, the satellite precipitation product data is: satellite precipitation product data with a half-hourly / 0.1° resolution.

[0007] In some embodiments, the tropical cyclone precipitation diurnal variation information includes: hourly precipitation statistics table, radial profile time series data, cumulative precipitation spatial distribution map, solar hour precipitation heat map and path overlay map; The hourly precipitation statistics table is in CSV format, and the radial profile time series data is in nested array format.

[0008] In some embodiments, the first preset value ranges from 0 km to 500 km.

[0009] The present application provides a tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator, comprising: An acquisition module is used to obtain high-resolution tropical cyclone path and precipitation data; wherein the tropical cyclone path includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; A conversion module is configured to convert the universal time information of each path point in the tropical cyclone path into solar tracking time information; specifically comprising: calculating the solar declination angle and the solar direct point based on the universal time information; and determining the solar tracking time information of each path point based on the position information of the path point, the relative relationship between the solar declination angle and the solar direct point; and a determination module is configured to determine, based on the tropical cyclone path, a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset value as the radius; An extraction module, configured to extract effective precipitation grids in the mask area based on the precipitation data, and determine precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; The analysis module is used to analyze the data to be analyzed using the time information of sun tracking as a label to obtain the diurnal variation information of tropical cyclone precipitation.

[0010] In some embodiments, the satellite precipitation product data is: satellite precipitation product data with a half-hourly / 0.1° resolution.

[0011] In some embodiments, the first preset value ranges from 0 km to 500 km.

[0012] The present application provides an electronic device, including: A processor, and a memory for storing a program executable by the processor; The processor is used to implement the above-mentioned tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator by running the program in the memory.

[0013] The present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the processor is enabled to execute the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator as described above.

[0014] The present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above-mentioned tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator.

[0015] The present application provides a tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator. The method first obtains high-resolution tropical cyclone path and precipitation data. The tropical cyclone path includes the position and universal time information of the tropical cyclone. The precipitation data includes satellite-based precipitation product data. The universal time information of each path point in the tropical cyclone path is converted into solar tracking time information. The method specifically includes: calculating the solar declination angle and the solar direct point based on the universal time information, and determining the solar tracking time information of each path point based on the relative relationship between the position information, solar declination angle and the solar direct point of the path point for each path point; determining a mask area composed of a circle with the tropical cyclone track point as the center and a first preset value as the radius based on the tropical cyclone path; extracting effective precipitation grids in the mask area based on the precipitation data, and determining the precipitation information and solar tracking time information corresponding to the effective precipitation grids as data to be analyzed; analyzing the data to be analyzed using the solar tracking time information as a label to obtain diurnal variation information of tropical cyclone precipitation. This setup, by constructing a Sun Tracking Time (STT) timeframe, overcomes the temporal bias inherent in traditional methods due to varying latitudes and longitudes. Combined with high-resolution tropical cyclone track and precipitation data, this method accurately aligns time and space, making it applicable to global precipitation analysis. Furthermore, the extracted diurnal variation in tropical cyclone precipitation can be directly used to study physical mechanisms and improve forecast models, providing a more scientific basis for meteorological research and disaster prevention, and possessing significant scientific application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other purposes, features, and advantages of the present application will become more apparent through a more detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are intended to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0017] Figure 1 This is a flow chart of a tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator provided in an embodiment of the present application.

[0018] Figure 2 This is a flow chart of a tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator provided in another embodiment of the present application.

[0019] Figure 3 This is a structural schematic diagram of a tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator provided in one embodiment of the present application.

[0020] Figure 4 This is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] The present invention aims to provide a method for analyzing the diurnal variation of tropical cyclone precipitation based on dynamic mapping of the solar terminator, so as to solve the problems existing in the current global research on the diurnal variation of tropical cyclone precipitation, such as inconsistent time frames and difficulty in decoupling physical mechanisms.

[0023] The technical solution includes the following steps: s1: Obtain high-resolution tropical cyclone track and precipitation data: Use tropical cyclone best-track datasets (such as IBTrACS) to obtain the position and time information of each tropical cyclone in UTC; obtain the IMERG satellite precipitation product with a half-hourly / 0.1° resolution; and accurately align the tropical cyclone track points with the IMERG precipitation data in both time and space. s2: Convert UTC time to Sun Tracking Time (STT): Use the longitude and latitude of the track points and UTC time to calculate the solar declination and the point of direct solar irradiance; establish a coordinate system with the antipodal point as the pole for mapping; assign each track point to a Sun Tracking Time zone and generate its corresponding STT time tag. s3: Extract the radial structure of tropical cyclone precipitation and associate it with STT: Construct a 50km radius of influence with each track point as the center; calculate the spherical distance from the center point using the Haversine algorithm; extract the corresponding precipitation grid and calculate: 50km average precipitation; radial annular distribution (with intervals every 25km); and classify the precipitation into corresponding STT hourly segments. s4: Statistics and output of STT hourly scale precipitation daily variation curve: all track points are grouped by sun tracking hour; average precipitation and sample number for each hour are calculated; global statistical table and regional distribution map of daily precipitation variation are output; further superposition of urban boundaries, land-sea distribution, tropical sea temperature field and other research is supported.

[0024] Compared with the existing technology, the significant technical effects of the present invention are: analysis based on the time axis of time information during sun tracking, avoiding the deviation in precipitation periodicity identification caused by traditional UTC or LST between different longitudes and latitudes; high-resolution physical alignment: combining IMERG satellite data with the TC center path, the precipitation structure has the characteristics of both spatial scale and temporal accuracy; strong global applicability: applicable to tropical cyclones within any longitude range, with versatility and scalability, for example, it can also be used to analyze the diurnal variation characteristics of tropical cyclone intensity, convection or wind field; assisting mechanism revelation and modeling improvement: the proposed diurnal variation extraction results can be directly used for tropical cyclone precipitation physical mechanism research, diurnal variation simulation improvement and machine learning model training, etc.

[0025] After introducing the basic principles of the present application, various non-limiting embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0026] Figure 1 This is a flow chart of a tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator provided by an embodiment of the present application. Figure 1 As shown, the method includes the following contents.

[0027] Step S110, obtaining high-resolution tropical cyclone path and precipitation data; wherein the tropical cyclone path includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; First, we need to obtain high-resolution tropical cyclone track and precipitation data. Tropical cyclone track data includes the position information of tropical cyclones at different points in time (such as latitude and longitude) and the corresponding Universal Time (UTC) information. This data can be obtained from authoritative meteorological databases such as the International Tropical Cyclone Track Archive (IBTrACS). At the same time, we also need to obtain satellite-based precipitation product data, which provides high-resolution precipitation information, typically with a half-hourly / 0.1° resolution. This data can be obtained from the Global Precipitation Measurement (GPM) mission's IMERG (Integrated Multi-satellite Retrievals for GPM) product. By accurately aligning tropical cyclone track points with satellite precipitation data in both time and space, we ensure that each track point has corresponding precipitation data.

[0028] Step S120, converting the Universal Time information of each path point in the tropical cyclone path into solar tracking time information, specifically comprising: calculating the solar declination angle and the solar direct point based on the Universal Time information, and determining the solar tracking time information of each path point based on the relative relationship between the path point's position information, the solar declination angle, and the solar direct point; Next, for each point in the tropical cyclone's path, we need to convert its Universal Time information into Sun Tracking Time (STT) time information. This conversion process includes the following detailed steps: Calculate the solar declination angle: Calculate the solar declination angle based on the number of days in the year for the current date.

[0029] Determine the sun's direct point: Calculate the longitude of the sun's direct point based on the current UTC time (UTC_time). The latitude of the sun's direct point is the calculated solar declination angle.

[0030] Determine the coordinates of the antipodal point: For each path point, calculate the coordinates of its antipodal point: Convert to spherical Cartesian coordinates: Convert the geographic coordinates (ϕ,λ) of each path point to spherical Cartesian coordinates (x,y,z): Rotate the coordinate system: Consider the antipodal point as the new pole and perform a three-dimensional rotation.

[0031] Convert the spherical Cartesian coordinates (x, y, z) of the path point to the new coordinates (x′, y′, z′) using the rotation matrix R; Convert back to spherical coordinates: Convert the rotated coordinates (x′, y′, z′) back to spherical coordinates (ϕ′, λ′); Convert λ′ to angle and make sure it is in the range [-180,180]; Calculate the STT value: translate the sub-sun point to the rotation longitude 180° and define the translation function; Normalize λshifted to the interval [-180,180]; Calculate the final STT value based on a time zone of 1 hour per 15°. Ensure that the STT value is within the range of [0, 23]. Step S130, based on the tropical cyclone path, determining a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset value as the radius; Based on the tropical cyclone's path, a circular area centered at each track point is defined as a mask. The radius of this circular area is set to a preset value, typically between 0 km and 500 km. The purpose of the mask is to limit the geographic scope of the analysis, ensuring that it is focused on the specific area associated with the tropical cyclone. This reduces interference from irrelevant data and improves analysis efficiency and accuracy.

[0032] Step S140: extracting effective precipitation grids in the mask area based on the precipitation data, and determining precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; Using the acquired satellite precipitation data, extract the effective precipitation grid within the mask area. The specific steps are as follows: Calculate spherical distance: For each path point, use the Haversine formula to calculate the spherical distance between all precipitation grid points in the mask area and the path point.

[0033] Extracting effective precipitation grids: Precipitation grid points within a preset radius on the spherical surface are selected as effective precipitation grids. For each effective precipitation grid, corresponding precipitation information, including precipitation amount and other data, is extracted. Determining STT time information: The precipitation information for each effective precipitation grid is associated with the corresponding STT time information to form the data to be analyzed. This data will be used in subsequent analysis processes.

[0034] Step S150 , analyzing the data to be analyzed using the sun tracking time information as a label to obtain the diurnal variation information of tropical cyclone precipitation.

[0035] Finally, the extracted data to be analyzed is analyzed using the sun tracking time information as a label. The specific steps are as follows: Group statistics: All valid precipitation grids are grouped according to STT time information, with each time period (such as every hour) as a group.

[0036] Calculate average precipitation: For each time period, calculate the average precipitation of all valid precipitation grids in that time period.

[0037] Generate analysis results: Based on the statistical results, generate information on the diurnal variation of tropical cyclone precipitation, including hourly precipitation statistics, radial profile time series data, cumulative precipitation spatial distribution maps, solar hour precipitation heat maps, and path overlay maps. This information helps to deepen the understanding of the patterns and characteristics of tropical cyclone precipitation, providing a scientific basis for meteorological research and disaster prevention.

[0038] Through the above detailed steps, this method can more accurately analyze the diurnal variation of tropical cyclone precipitation, overcoming the problems caused by inconsistent time frames and insufficient data resolution in traditional methods.

[0039] Specifically, the satellite precipitation product data is: satellite precipitation product data with a half-hourly / 0.1° resolution.

[0040] The tropical cyclone precipitation diurnal variation information specifically includes: hourly precipitation statistics table, radial profile time series data, cumulative precipitation spatial distribution map, solar hour precipitation heat map and path overlay map; wherein, the hourly precipitation statistics table is in CSV format, and the radial profile time series data is in nested array format.

[0041] The tropical cyclone precipitation diurnal variation information specifically includes the following data output forms, which help to analyze and understand the characteristics and patterns of tropical cyclone precipitation from different perspectives: The hourly precipitation statistics table is formatted as a CSV file and records the average precipitation for each Sun Tracking Time (STT) period. Each row represents a time period (e.g., each hour), and columns include information such as the time period label (STT time), average precipitation, and sample size. For example, the table might show that the average precipitation between 12:00 and 13:00 STT was 5.2 mm, with a sample size of 30 valid precipitation grids.

[0042] Through hourly precipitation statistics, we can clearly observe the daily variation pattern of tropical cyclone precipitation, identify the peak and trough periods of precipitation intensity, and help understand the daily periodicity of precipitation.

[0043] Radial profile time series data is formatted as a nested array. This data format provides a time series of tropical cyclone precipitation variations at different radial distances. The data records the average precipitation for each annulus at predetermined radial distances (e.g., one annulus every 25 kilometers) centered on the tropical cyclone track point during different STT periods. For example, the data might show that from 12:00 to 1:00 STT, the average precipitation at annulus 50 kilometers from the center was 4.5 mm, while the average precipitation at annulus 100 kilometers was 3.0 mm.

[0044] Radial profile time series data help analyze the spatial distribution characteristics of precipitation and its changes over time, revealing how precipitation intensity changes with increasing distance from the center of a tropical cyclone, which is of great significance for understanding the structure and dynamic processes of tropical cyclones.

[0045] Spatial distribution of accumulated precipitation: This map shows the spatial distribution of accumulated precipitation around a tropical cyclone's path over a specific time period (e.g., a single day or the life cycle of a tropical cyclone). Different colors or contour lines represent different precipitation levels, visually highlighting areas of high and low precipitation values ​​and the unevenness of precipitation distribution.

[0046] Through the spatial distribution map of cumulative precipitation, we can quickly identify the main affected areas of tropical cyclone precipitation, assess the precipitation risks in different regions, and provide a basis for disaster prevention and resource management.

[0047] Solar Time Precipitation Heat Map: This heat map uses color to represent precipitation amounts. The horizontal axis represents Sun Tracking Time (STT), and the vertical axis represents different locations along the tropical cyclone's path (which can be latitude, longitude, or distance from the center). Darker colors indicate heavier precipitation, while lighter colors indicate lighter precipitation. This intuitively illustrates the temporal and spatial trends of precipitation. Solar Time Precipitation Heat Maps can visually demonstrate the diurnal variation of tropical cyclone precipitation and the differences in precipitation intensity at different locations. This helps identify the temporal and spatial characteristics of precipitation, providing strong support for meteorological forecasting and research.

[0048] Track Overlay: This overlay maps the path of a tropical cyclone onto a precipitation distribution map, clearly showing the position of the tropical cyclone at different points in time and its relationship to precipitation distribution. Different colors or symbols can be used to represent different points in time, and precipitation contours or color changes are also indicated. Track overlays help analyze the impact of a tropical cyclone's track on precipitation distribution and understand how precipitation changes with the cyclone's movement. They are of great value in studying the dynamics of tropical cyclones and the formation of precipitation.

[0049] Through this detailed daily variation information of tropical cyclone precipitation, researchers and weather forecasters can gain a more comprehensive and in-depth understanding of the characteristics and patterns of tropical cyclone precipitation, thereby improving their ability to predict tropical cyclone precipitation and respond to disasters.

[0050] Furthermore, the first preset value ranges from 0km to 500km. In this application, the first preset value refers to a parameter used to determine the radius of the mask area. This parameter plays a key role in analyzing tropical cyclone precipitation because it defines the analysis range around the tropical cyclone track point. Specifically, the first preset value ranges from 0km to 500km. The following is a detailed description of this value range: The first preset value is a key parameter that defines the radius of a circular mask centered on the tropical cyclone track. This radius determines the geographic scope of the analysis, ensuring that the analysis is focused on the specific area associated with the tropical cyclone while reducing interference from irrelevant data.

[0051] The selection of a range of 0 km to 500 km as the first preset value is based on the following considerations: Typical tropical cyclone impact range: Tropical cyclones typically have an impact range of thousands of kilometers, especially in the case of strong tropical cyclones (such as hurricanes or typhoons). Research shows that the precipitation impact range of tropical cyclones is typically between 0 km and 500 km. This range covers the primary precipitation regions of tropical cyclones while avoiding excessive expansion of the analysis scope, reducing computational complexity and data processing. Data resolution and analysis accuracy: The selection of a range of 0 km to 500 km ensures sufficient accuracy and reliability of analysis results using high-resolution data (such as half-hourly / 0.1° resolution satellite precipitation products). This range captures the key characteristics of tropical cyclone precipitation without missing important information due to a narrow range. In practical applications, weather forecasting and disaster prevention require analysis within a reasonable range to ensure that the results are meaningful. The range of 0 km to 500 km meets these requirements, providing sufficient information for assessing the impact of tropical cyclone precipitation while avoiding unnecessary computation and data processing.

[0052] In practice, the specific value of the first preset value can be adjusted based on specific research objectives and data availability. For example: 0 km is suitable for detailed analysis over a smaller area, more accurately capturing the local characteristics of tropical cyclone precipitation. 500 km is suitable for comprehensive analysis over a larger area, providing a more comprehensive picture of precipitation distribution and suitable for large-scale meteorological research and disaster assessment.

[0053] Suppose we are analyzing the precipitation characteristics of a strong tropical cyclone and select 500km as the first preset value. This means that a circular mask area with a radius of 500km is constructed with the tropical cyclone track point as the center. Within this area, all valid precipitation grids are extracted and further analyzed. In this way, we can ensure that the analysis is focused on the main influence area of ​​the tropical cyclone while reducing the interference of irrelevant data. The first preset value ranges from 0km to 500km. This range is selected based on the typical influence area of ​​tropical cyclones, data resolution, and actual application requirements. By reasonably selecting the first preset value, we can ensure that the analysis results have sufficient accuracy and reliability while meeting the actual needs of meteorological research and disaster prevention.

[0054] The following combination Figure 2 , further explain the solution provided in this application: The present invention provides a method for analyzing the diurnal variation of tropical cyclone precipitation based on dynamic mapping of the solar terminator. The core idea is to use Solar Tracking Time (STT) as the time reference frame to perform spatiotemporal extraction and statistical analysis of the global tropical cyclone precipitation field, thereby revealing the diurnal variation rhythm of the precipitation system.

[0055] Step 1: Obtain a global tropical cyclone track dataset, such as the International Best Track Archive for Climate Stewardship (IBTrACS), which contains information such as the center latitude and longitude, UTC time, and intensity level of each tropical cyclone at different time steps. This dataset is converted to a standard datetime object and set to Coordinated Universal Time (UTC). Based on this, GPM IMERG Final Run data, a global half-hourly, 0.1° resolution satellite precipitation product, is introduced. Based on the time of the track point, the " / Grid / precipitation" data layer in the precipitation data file is accurately read. The corresponding latitude and longitude grid (lon / lat) is also extracted, and the tropical cyclone track points are precisely aligned with the IMERG precipitation data in both time and space.

[0056] Step 2: To accurately describe the precipitation rhythm under the influence of solar radiation, the UTC time of each track point needs to be converted to Sun Tracking Time (STT). The conversion process includes four steps: Step 2.1, calculate the current solar declination angle in degrees, using the following formula:

[0057] in is the solar declination angle, What day of the year does that day fall on? 81 is approximately the Spring Equinox (March 21). Step 2.2, calculate the sun's direct point, assuming the current UTC time is:

[0058] The longitude of the sun's direct point is:

[0059] Longitude normalized to interval :

[0060] The latitude of the sun's direct point is:

[0061] in, is UTC time, hour is hour, min is minute, sec is second, is the longitude of the sun's direct point, is the latitude of the point where the sun is directly overhead.

[0062] Step 2.3, define the antipodal point coordinates:

[0063] And normalize it:

[0064] Then the coordinates are rotated to the coordinate system with the antipodal point as the pole; given the coordinates of any point on the surface of the earth , first convert to spherical Cartesian coordinate system:

[0065] Perform a 3D rotation (or shift around the pole) using the antipodal point as the new pole:

[0066] Convert back to spherical coordinates (after rotation):

[0067] and will Convert to angle system.

[0068] in, is the (latitude, longitude) of the topology point, are the coordinates (latitude, longitude) of any point on the Earth's surface, are the three-dimensional Cartesian coordinates on the unit sphere, is the new system coordinate after rotation, are the rotated spherical coordinates (latitude, longitude).

[0069] Step 2.4, translate the sub-sun point to the rotation longitude of 180°. The longitude of the rotated sub-sun point is recorded as To center it (i.e. STT = 12 corresponds to a rotation of 180° in longitude), we perform an angular translation and define the translation function:

[0070] And normalize so that all longitudes :

[0071] Then, every 15° is 1 hour:

[0072] This is the final Solar Tracking Time (STT) value, which ranges from [0,23].

[0073] in, is the translation function, is the longitude after rotation, is the rotation longitude of the sub-sun point, is the translation angle, is the final longitude after translation and normalization, It is a normalization function, and mod represents the modular operation, which means the remainder is retained after dividing two numbers.

[0074] Step 3: Construct a circular precipitation extraction mask area with a radius of 500 km and centered at the typhoon track point, and extract all valid precipitation grids within it:

[0075] The spherical distance is calculated using the latitude and longitude of the center of the trajectory point and the latitude and longitude of the precipitation data grid point using the Haversine formula:

[0076] in is the mask area with a radius of 500km, are the latitude and longitude of the geographic grid, is the distance from the point to the sphere, R = 6371 km is the average radius of the earth, , and , are the latitude and longitude of the grid point and the trajectory center point, respectively (in radians).

[0077] Extract all effective precipitation values ​​P(x, y) ≥ 0.1 mm / h from area A500, and its average precipitation intensity is:

[0078] in is the average precipitation intensity within a 50km area, is the number of valid grid points that meet the conditions.

[0079] It is further divided into 20 radial belts of equal width of 25 km, each with a width of 25 km. The rth belt area is defined as:

[0080] The average precipitation intensity in each ring belt is calculated separately. The average precipitation intensity in the rth ring belt is:

[0081] in, is the rth annular zone, is the ring width, is the number of effective precipitation grids in the rth annulus.

[0082] At this point, the radial precipitation profile of this path point is constructed.

[0083] Step 4: Process all tropical cyclone path points point by point, using their STT hours (0-23 hours) as classification labels. Based on this, calculate the mean precipitation value (e.g., the average value of a 500 km circular area) and the number of samples corresponding to all path points within each STT hour to construct the following function:

[0084] in, is the average precipitation intensity corresponding to time h, is the number of valid path points in this period, is the regional average precipitation value at the i-th path point. Based on this, a global average precipitation diurnal variation curve can be drawn with the sun tracking time as the horizontal axis, revealing the systematic diurnal variation of precipitation activity under the influence of the relative position of the sun.

[0085] To enhance practicality, this method also supports the output of a variety of structured results, including hourly precipitation statistics tables (CSV format), radial profile time series data (nested arrays), cumulative precipitation spatial distribution maps, solar hour precipitation heat maps, and path overlay maps, etc., which are convenient for further use in climate law extraction, tropical cyclone structure research, and precipitation heterogeneity evaluation.

[0086] In summary, this invention uses solar time as the unified time coordinate, and through precise path matching and high-resolution precipitation extraction, combined with spherical distance modeling and astronomical time correction, constructs a complete set of precipitation diurnal variation research methods applicable to global tropical cyclone events. It solves the problem of precipitation identification deviation at different longitude path points in the traditional UTC framework, and provides new ideas and tools for the physical understanding and modeling of tropical cyclone precipitation.

[0087] Exemplary devices The device embodiments of this application can be used to execute the method embodiments of this application. For details not disclosed in the device embodiments of this application, please refer to the method embodiments of this application.

[0088] Figure 3 FIG. 1 is a block diagram of a tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator provided by an embodiment of the present application. Figure 3 As shown, the device includes: An acquisition module 31 is configured to acquire high-resolution tropical cyclone path and precipitation data; wherein the tropical cyclone path includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; The conversion module 32 is configured to convert the universal time information of each path point in the tropical cyclone path into solar tracking time information. The specific steps are as follows: based on the universal time information, the solar declination angle and the solar direct point are calculated; for each path point, the solar tracking time information of the path point is determined based on the position information of the path point, the relative relationship between the solar declination angle and the solar direct point; the determination module is configured to determine, based on the tropical cyclone path, a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset radius as the radius; An extraction module 33 is configured to extract effective precipitation grids in the mask area based on the precipitation data, and determine precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; The analysis module 34 is configured to analyze the data to be analyzed using the time information of the sun tracking as a label to obtain the diurnal variation information of tropical cyclone precipitation.

[0089] In some embodiments, the satellite precipitation product data is: satellite precipitation product data with a half-hourly / 0.1° resolution.

[0090] In some embodiments, the first preset value ranges from 0 km to 500 km.

[0091] Below, reference Figure 4 To describe the electronic device according to the embodiment of the present application. Figure 4 The figure shows a block diagram of an electronic device according to an embodiment of the present application.

[0092] like Figure 4 As shown, electronic device 400 includes one or more processors 410 and memory 420 .

[0093] The processor 410 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 400 to perform desired functions.

[0094] The memory 420 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 410 may execute the program instructions to implement the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator and / or other desired functions of the various embodiments of the present application described above. Various contents such as category correspondences may also be stored in the computer-readable storage medium.

[0095] In one example, the electronic device 400 may further include an input device 430 and an output device 440 , and these components are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0096] In addition, the input device 430 may also include, for example, a keyboard, a mouse, an interface, etc. The output device 440 may output various information to the outside, including analysis results, etc. The output device 440 may include, for example, a display, a speaker, a printer, a communication network and its connected remote output device, etc.

[0097] Of course, to simplify, Figure 4 Only some of the components in the electronic device related to the present application are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application scenarios.

[0098] In addition to the above-mentioned methods and devices, an embodiment of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to various embodiments of the present application described in the above-mentioned "Exemplary Method" section of this specification.

[0099] The computer program product may be written in any combination of one or more programming languages ​​to implement the program code for performing the operations of the embodiments of the present application, including object-oriented programming languages ​​such as Python, Java, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0100] In addition, an embodiment of the present application may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enables the processor to execute the steps of the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to various embodiments of the present application described in the above "Exemplary Method" section of this specification.

[0101] The computer-readable storage medium may be any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may include, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0102] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator, characterized in that: include: Acquire high-resolution tropical cyclone track and precipitation data; wherein the tropical cyclone track includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; Converting the universal time information of each path point in the tropical cyclone path into solar tracking time information; specifically, calculating the solar declination angle and the solar direct point based on the universal time information, and determining the solar tracking time information of each path point based on the relative relationship between the path point's position information, the solar declination angle, and the solar direct point; Based on the tropical cyclone path, determining a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset value as the radius; Extracting effective precipitation grids in the mask area based on the precipitation data, and determining precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; The data to be analyzed is analyzed using the sun tracking time information as a label to obtain the diurnal variation information of tropical cyclone precipitation.

2. The tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to claim 1, characterized in that: The satellite precipitation product data specifically refers to satellite precipitation product data with a half-hourly / 0.1° resolution.

3. The tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to claim 1, characterized in that: The tropical cyclone precipitation diurnal variation information specifically includes: hourly precipitation statistics table, radial profile time series data, cumulative precipitation spatial distribution map, solar hour precipitation heat map and path overlay map; The hourly precipitation statistics table is in CSV format, and the radial profile time series data is in nested array format.

4. The tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to claim 1, characterized in that: The first preset value ranges from 0 km to 500 km.

5. A tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator, characterized in that: include: An acquisition module is used to obtain high-resolution tropical cyclone path and precipitation data; wherein the tropical cyclone path includes the location and universal time information of the tropical cyclone; and the precipitation data includes satellite-based precipitation product data; A conversion module is configured to convert the universal time information of each path point in the tropical cyclone path into solar tracking time information. The specific steps are as follows: based on the universal time information, calculating the solar declination angle and the solar direct point, and for each path point, determining the solar tracking time information of the path point based on the position information of the path point, the relative relationship between the solar declination angle and the solar direct point; a determination module is configured to determine, based on the tropical cyclone path, a mask area consisting of a circle with the tropical cyclone track point as the center and a first preset value as the radius; An extraction module, configured to extract effective precipitation grids in the mask area based on the precipitation data, and determine precipitation information and sun tracking time information corresponding to the effective precipitation grids as data to be analyzed; The analysis module is used to analyze the data to be analyzed using the time information of sun tracking as a label to obtain the diurnal variation information of tropical cyclone precipitation.

6. The tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator according to claim 5, characterized in that: The satellite precipitation product data is: satellite precipitation product data with a half-hourly / 0.1° resolution.

7. The tropical cyclone precipitation analysis device based on dynamic mapping of the solar terminator according to claim 5, characterized in that: The first preset value ranges from 0 km to 500 km.

8. An electronic device, characterized in that: include: A processor, and a memory for storing a program executable by the processor; The processor is configured to implement the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator as described in any one of claims 1 to 4 by running the program in the memory.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, enables the processor to execute the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to any one of claims 1 to 4.

10. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a processor, implements the tropical cyclone precipitation analysis method based on dynamic mapping of the solar terminator according to any one of claims 1 to 4.

Images