Ocean mesoscale vortex energy conversion analysis method

Abstract

The invention particularly discloses an ocean mesoscale vortex energy conversion analysis method, and relates to the technical field of ocean dynamics. The method comprises the following steps: firstly, determining basic characteristics of a target vortex based on satellite remote sensing and observation data, obtaining high-resolution gridding data, determining a vortex center and a boundary by using a vortex detection algorithm, and constructing a trajectory through a tracking algorithm; secondly, energy conversion of the vortex and the average flow is quantified by means of an oblique pressure conversion term and a positive pressure conversion term; and finally, the contribution of power items such as positive pressure instability, oblique pressure conversion and wind stress input to the vortex kinetic energy is quantified by utilizing a vortex kinetic energy contracting and expanding equation. According to the method, the detection precision of the weak-amplitude and short-life vortex is improved, quantitative calculation of vortex energy exchange is realized, and the method can be widely applied to vortex energy income and expenditure analysis.

Description

Technical Field

[0001] The present invention relates to the field of ocean dynamics technology, in particular to an ocean mesoscale vortex energy conversion analysis method. Background Art

[0002] Mesoscale eddies are key dynamic processes in the ocean, and their energy conversion mechanisms are of great significance to ocean circulation and climate systems. However, existing technologies for quantitatively analyzing eddy energy are mostly limited to calculating single kinetic or potential energy or single mechanisms, failing to fully describe the energy conversion process. Furthermore, the lack of adaptability of detection and tracking methods can lead to biased analysis results.

[0003] Specifically, existing studies analyzing the energy conversion mechanisms of mesoscale vortices have mostly employed vortex detection methods based on preset amplitudes or single physical characteristics (such as the common OW method). These methods fail to fully consider the propagation characteristics of Rossby waves and can easily cause vortex trajectories to break or spurious merge. Furthermore, fixed-threshold detection algorithms struggle to capture vortices with weak amplitudes or short lifespans, leading to biased energy budget statistics.

[0004] In the analysis of vortex energy and dynamic mechanisms, existing studies often only perform separate calculations on a single kinetic or potential energy, or a single dynamic mechanism. This approach results in a lack of energy coupling within the vortex. For example, the baroclinic and barotropic conversion processes are analyzed independently, ignoring the dynamic impact of their synergistic effects on the vortex life cycle. Although some researchers have attempted to introduce data assimilation or machine learning techniques to improve vortex identification and tracking, and to analyze vortex energy based on this, these methods suffer from high computational complexity, and the analysis results are highly dependent on the universality of the training data. Summary of the Invention

[0005] The purpose of this invention is to propose a method for analyzing the energy conversion of mesoscale eddies in the ocean, which realizes high-precision and systematic analysis of the energy conversion of mesoscale eddies through the full process quantification of coupled detection-tracking-energy budget equations.

[0006] To achieve the above objectives, the present invention proposes a method for analyzing ocean mesoscale eddy energy conversion, which includes the following steps:

[0007] Step S1, determining the basic characteristics of the target mesoscale vortex based on satellite remote sensing and observation data, downloading high-resolution gridded data with a temporal and spatial range larger than the estimated area, and performing data preprocessing;

[0008] Step S2: Detect the target mesoscale vortex using a vortex detection algorithm to determine the center and boundary range of the vortex;

[0009] Step S3: Based on the detection result in step S2, the target mesoscale vortex is tracked using a vortex tracking algorithm;

[0010] Step S4: Calculate the vortex kinetic energy EKE and the vortex effective potential energy EPE using the high-resolution gridded data obtained in step S1;

[0011] Step S5: quantifying the energy conversion process through the baroclinic conversion term T2 and the barotropic conversion term T4, and calculating the energy conversion between vortex energy and mean flow energy;

[0012] Step S6: construct the kinetic energy budget equation to calculate the contributions of barotropic instability BTC, baroclinic conversion VEDF, wind stress input WW, pressure work PW and advection ADV to the vortex kinetic energy;

[0013] Step S7: Generate a time series of each item through depth integration and spatial averaging to achieve quantitative calculation of vortex energy exchange.

[0014] Preferably, in step S1, the range of the downloaded data needs to be slightly larger than the estimated range in both time and space scales, and the collected data is preprocessed and interpolated to the standard layer in depth.

[0015] Preferably, in step S2, the specific steps of the vortex detection algorithm are:

[0016] Step S21: Based on the sea surface height anomaly (SLA) data provided by the satellite altimeter, identify local maxima and local minima in the daily data snapshots through a 5×5 neighborhood search;

[0017] Step S22: performing noise filtering on the extreme points, including: removing noise interference through a 3×3 neighborhood; verifying the validity of the extreme points through a 7×7 neighborhood;

[0018] Step S23: Starting from the extreme point, the iterative threshold method is used to expand outward with an iterative step length of 0.05 cm to calculate the closed-loop contour line until the termination condition is met;

[0019] Step S24, determining the vortex boundary by the reverse backtracking method;

[0020] Step S25: retain the closed vortex structure with a spatial resolution of not less than 0.25°×0.25° and a grid number of ≥4.

[0021] Preferably, in step S23, the termination conditions include: a new extreme point appears in the closed-loop region; the number of iterations of the extreme point no longer increases; and the closed-loop contour line cannot continue to expand.

[0022] Preferably, in step S3, the main steps of vortex tracking are:

[0023] Step S31: Based on the Rossby phase velocity theory, the search range of vortex propagation is limited, and the nearest neighboring vortices in time and space are preferentially matched to construct the trajectory;

[0024] Step S32: Constraining the vortex matching conditions at adjacent times t and t+1 through attribute consistency check, including: controlling the vortex area change amplitude within the range of 0.25-2.75 times; controlling the vortex amplitude change amplitude within the range of 0.25-2.75 times;

[0025] Step S33: For vortices that disappear for less than one day, insert virtual vortex nodes to maintain trajectory continuity, and use linear extrapolation to calculate the virtual node positions based on historical propagation speeds;

[0026] Step S34: Eliminate virtual vortex nodes from the final trajectory data.

[0027] Preferably, in step S4, the calculation method of the vortex kinetic energy EKE and the vortex effective potential energy EPE is as follows:

[0028] Step S41: Extract the latitudinal and longitudinal components u and v of the horizontal flow field, and define the background field of the velocity component. The original flow velocity is decomposed by the change rate u' and v' during the vortex duration, and the calculation relationship of each parameter is as follows:

[0029]

[0030] Where u' is the rate of change of the latitudinal component of velocity, is the latitudinal component of the background velocity, v' is the rate of change of the longitudinal component of the velocity, is the meridional component of the background field velocity;

[0031] Step S42, the calculation formula of the vortex kinetic energy EKE is as follows:

[0032]

[0033] Where ρ0 is the reference density;

[0034] Step S43: Using the temperature, salinity, and pressure data of the seawater, the seawater density ρ(x, y, z, t) and the potential density ρ of the background field are calculated based on the seawater state equation UNESCO EOS-80. θ (z); The background density related to depth is obtained by spatial averaging over the study area and temporal averaging during the existence of the vortex, and the disturbance density is calculated as follows:

[0035]

[0036] in, is the perturbation density, ρ b(z) is the background density related to depth, x is the longitude coordinate, y is the latitude coordinate, z is the depth, and t is the time;

[0037] Step S44: Calculate the effective potential energy of the vortex at each grid point within the vortex range using the following formula:

[0038]

[0039] Where g is the gravitational constant, is the rate of change of disturbance density, ρ is the density, is the background field potential density.

[0040] Preferably, in step S5, the baroclinic conversion term T2 is calculated as follows:

[0041]

[0042] in, is the background field disturbance density;

[0043] The calculation formula for the positive pressure conversion term T4 is as follows:

[0044]

[0045] Preferably, in step S6, a kinetic energy budget equation is constructed, and the formula is as follows:

[0046]

[0047] in, It represents the time rate of change of vortex kinetic energy;

[0048]

[0049] WW=u′τ′ x +v′τ′ y ;

[0050]

[0051] Where w' is the vertical velocity change rate, τ' x is the rate of change of wind stress component in the x direction, τ' y is the rate of change of the wind stress component in the y direction, and p' is the rate of change of the sea water pressure;

[0052] Preferably, the x-direction component of wind stress τ x and the y-direction component τ y The calculation formula is as follows:

[0053] τ x =ρ·C d ·|U 10 |·u 10;

[0054] τ y =ρ·C d ·|U 10 |·v 10 ;

[0055] Among them, U 10 is the wind speed at 10m above sea level, u 10 and v 10 are the wind speeds in the x and y directions of the wind field 10 m above the sea surface, C d is the drag coefficient, which is calculated as follows:

[0056]

[0057] Preferably, in step S7, the steps for calculating the time series of each item in the vortex are as follows:

[0058] Step S71, determining the vortex inner grid point and the vortex outer grid point according to the vortex range at each time point obtained in step S3;

[0059] Step S72: Select the depth within the vortex influence range and perform depth integration at the grid points within the vortex;

[0060] Step S73: spatially average the grid point integration results of the vortex at each time to obtain various time series.

[0061] Therefore, the present invention proposes a method for analyzing ocean mesoscale eddy energy conversion, which has the following beneficial effects:

[0062] (1) Strong adaptability: The present invention adopts iterative threshold method and dynamic noise filtering technology, without the need to preset vortex amplitude or life threshold, and can accurately identify mesoscale vortices of different intensities and scales, and is particularly suitable for the detection of weak signal vortices;

[0063] (2) High physical consistency: Based on the Rossby phase velocity theory, the vortex tracking search range is constrained, and combined with the virtual node interpolation technology, the spatiotemporal continuity of the vortex trajectory is ensured to avoid false mergers or breaks;

[0064] (3) Comprehensive energy coupling analysis: Through the joint calculation of the baroclinic conversion term (T2) and the barotropic conversion term (T4), the energy exchange between the vortex and the background flow is quantified, overcoming the limitation of traditional methods that only focus on a single energy or dynamic mechanism form;

[0065] (4) Computational efficiency optimization: Using layered depth integration and intra-vortex grid point spatial averaging strategies, the amount of data calculation is reduced while ensuring accuracy, which is suitable for large-scale and long-time series analysis;

[0066] (5) Wide range of applications: This method is compatible with satellite altimeters, reanalysis data, and field observation data, providing a general technical framework for ocean circulation diagnosis and eddy-climate interaction research.

[0067] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a flow chart of a method for analyzing ocean mesoscale eddy energy conversion according to the present invention;

[0069] Figure 2 is a schematic diagram of vortex identification and tracking results in an embodiment of the present invention;

[0070] Figure 3 is a diagram of the vortex energy level distribution in an embodiment of the present invention; wherein, Figure 3 (a) is the horizontal distribution of EKE, Figure 3 (b) shows the horizontal distribution of EPE, which is displayed at four time points: December 12, January 31, March 7, and April 7.

[0071] Figure 4 is a horizontal distribution diagram of energy conversion between vortex and background average flow in an embodiment of the present invention; wherein, Figure 4 (a) is the horizontal distribution of T2, Figure 4 (b) shows the horizontal distribution of T4, with four time nodes selected: December 12, January 31, March 7, and April 7.

[0072] Figure 5 is a schematic diagram of the average time series in the vortex of each dynamic mechanism in the embodiment of the present invention; wherein, Figure 5 a in the figure is a schematic diagram of the average time series in the vortex of PW. Figure 5 b in the figure is a schematic diagram of the average time series of BTC and WW in the vortex. Figure 5 c in the figure is a schematic diagram of the average time series of ADV in the vortex. Figure 5 The d in the figure is a schematic diagram of the intra-eddy average time series of VEDF. DETAILED DESCRIPTION

[0073] To make the technical solutions, advantages, and objectives of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0074] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0075] Example 1

[0076] This example selects a long-distance migrating anticyclonic vortex in a certain sea area during the winter and spring of 2009-2010. Based on satellite remote sensing data, the basic situation of the target mesoscale vortex is determined. It is roughly estimated that the spatial range of the anticyclonic vortex's life cycle is approximately between 16°N and 21°N and 111°E and 121°E, and the time range is approximately from December 2009 to April 2010. The relevant energy conversion calculation of the anticyclonic vortex is performed.

[0077] like Figure 1 FIG. 1 is a flow chart of a method for analyzing ocean mesoscale eddy energy conversion according to the present invention, and the specific steps are as follows:

[0078] S1. Collect high-resolution reanalysis gridded data with a temporal and spatial range larger than the estimated area (a rectangular area between 15°N and 22°N, 110°E and 122°E, from November 2009 to May 2010). Perform data preprocessing and vertically interpolate the 50 layers of 0.083° × 0.083° high-resolution data provided by the reanalysis data onto the standard layer.

[0079] S2. Use the vortex detection algorithm to detect the target mesoscale vortex and determine the center and boundary range of the vortex. The steps are as follows:

[0080] Firstly, based on the sea surface height anomaly (SLA) data provided by satellite altimeters, local maxima (anticyclonic vortices) are identified in daily data snapshots through a 5×5 neighborhood search.

[0081] Then, the extreme point is filtered for noise, and noise interference is eliminated through a 3×3 neighborhood. The validity of the extreme point is verified through a 7×7 neighborhood to reduce the false detection rate. Then, starting from the extreme point, the iterative threshold method is used to expand outward with an iteration step of 0.05 cm to calculate the closed-loop contour line until one of the following termination conditions is met: a new extreme point appears in the closed-loop area; the number of iterations of the extreme point no longer increases; the closed-loop contour line cannot be further expanded;

[0082] Finally, the vortex boundary is determined by the reverse backoff method to avoid false detection caused by the merging of neighboring vortices; and the closed vortex structure with a spatial resolution of not less than 0.25°×0.25° and a grid number ≥4 is retained, without presetting the amplitude or lifetime threshold, in order to adapt to different ocean vortex characteristics.

[0083] S3, based on the vortex detection results at each moment obtained in S2, the target mesoscale vortex is tracked using the vortex tracking algorithm. The vortex identification and tracking results are as follows: Figure 2 As shown, the steps are as follows:

[0084] Firstly, the search range of vortex propagation is limited based on Rossby phase velocity theory, and the nearest neighboring vortices in time and space are preferentially matched to construct the trajectory.

[0085] Then, the matching conditions of vortices at adjacent times (t and t+1) were constrained by attribute consistency checks, including: the change amplitude of vortex area was controlled within the range of 0.25–2.75 times; the change amplitude of vortex amplitude was controlled within the range of 0.25–2.75 times; in addition, for vortices that disappeared briefly (disappearance time ≤ 1 day), virtual vortex nodes were inserted to maintain trajectory continuity, and the positions of virtual nodes were calculated by linear extrapolation based on the historical propagation speed;

[0086] Finally, virtual nodes are removed from the final trajectory data to ensure physical consistency.

[0087] S4, such as Figure 3 As shown, the vortex kinetic energy EKE and vortex effective potential energy EPE are calculated using the high-resolution gridded data obtained in step S1. The specific calculation method is as follows:

[0088] S41. Extract the latitudinal and longitudinal components u and v of the horizontal flow field and define the background field of the velocity component The original flow velocity is decomposed by the change rate u' and v' during the vortex duration, and the calculation relationship of each parameter is as follows:

[0089]

[0090] Where u' is the rate of change of the latitudinal component of velocity, is the latitudinal component of the background velocity, v' is the rate of change of the longitudinal component of the velocity, is the meridional component of the background field velocity;

[0091] S42. The calculation formula of vortex kinetic energy EKE is as follows:

[0092]

[0093] Where ρ0 is the reference density, which is 1024 kg / m 3 ;

[0094] S43. Using seawater temperature, salinity, and pressure data, calculate the seawater density ρ(x, y, z, t) and the background field potential density ρ based on the seawater state equation UNESCO EOS-80. θ (z); The background density related to depth is obtained by spatial averaging over the study area and temporal averaging during the existence of the vortex, and the disturbance density is calculated as follows:

[0095]

[0096] in, is the perturbation density, ρ b (z) is the background density related to depth, x is the longitude coordinate, y is the latitude coordinate, z is the depth, and t is the time;

[0097] S44. Calculate the effective potential energy of the vortex at each grid point within the vortex range using the following formula:

[0098]

[0099] Where g is the gravitational constant, is the rate of change of disturbance density, ρ is the density, is the background field potential density.

[0100] S5. The energy conversion process is quantified by the barotropic conversion term T2 and the barotropic conversion term T4. The energy conversion between vortex energy and mean flow energy is calculated. The vortex energy level distribution is as follows: Figure 4 As shown;

[0101] The baroclinic conversion term T2 is calculated as follows:

[0102]

[0103] in, is the background field disturbance density;

[0104] The calculation formula for the positive pressure conversion term T4 is as follows:

[0105]

[0106] T2 represents the conversion between the average potential energy of the background flow and the effective potential energy of the vortex, and T4 represents the work done by the Reynolds stress on the average shear, which is the conversion between the average kinetic energy of the background flow and the kinetic energy of the vortex. Positive values ​​of both indicate the occurrence of barotropic instability and barotropic instability. These two values ​​are used to evaluate the energy conversion between the vortex and the background flow.

[0107] S6: As Figure 5 As shown, the kinetic energy budget equation is constructed to calculate the contributions of barotropic instability BTC, baroclinic conversion VEDF, wind stress input WW, pressure work PW and advection ADV to the vortex kinetic energy;

[0108] Among them, the formula for constructing the kinetic energy budget equation is as follows:

[0109]

[0110] in, It represents the time rate of change of vortex kinetic energy;

[0111] Barobaric instability BTC describes the conversion of the average kinetic energy of the background flow into eddy kinetic energy. If this term is positive, it indicates that barobaric instability has occurred. The formula is as follows:

[0112]

[0113] The baroclinic conversion VEDF represents the baroclinic conversion caused by the vertical vortex density flux, that is, the conversion of the vortex effective potential energy EPE to EKE. The calculation formula is as follows:

[0114]

[0115] The wind stress input WW represents the EKE generated by the sea surface wind stress input. This term relates the time-varying surface wind stress to the ocean circulation. The calculation formula is as follows:

[0116] WW=u′τ′ x +v′τ′ y ;

[0117] Pressure work PW and advection ADV represent the redistribution of EKE by pressure work and ocean advection, respectively. Based on the constructed kinetic energy budget equation, the common difference method in fluid mechanics is used to solve the spatiotemporal distribution and changes of the effects of various dynamic mechanisms in the vortex. The calculation formula is as follows:

[0118]

[0119] Where w' is the vertical velocity change rate, τ' x is the rate of change of wind stress component in the x direction, τ' y is the rate of change of the wind stress component in the y direction, and p' is the rate of change of the sea water pressure;

[0120] In the wind stress input WW calculation formula, the wind stress x-direction component τ x and the y-direction component τ y The calculation formula is as follows:

[0121] τ x =ρ·C d ·|U 10 |·u 10 ;

[0122] τ y =ρ·C d ·|U 10 |·v 10 ;

[0123] Among them, U 10 is the wind speed at 10m above sea level, u 10 and v10 are the wind speeds in the x and y directions of the wind field 10 m above the sea surface, C d is the drag coefficient, which is calculated as follows:

[0124]

[0125] S7: Determine the grid points inside and outside the vortex according to the vortex range at each time point obtained in S3, establish a data mask grid, fill the points inside the vortex with 1, and fill the points outside the vortex with 0. Select the depth within the main influence range of the vortex, and perform depth integration at the grid points inside the vortex (that is, the logical judgment is 1). In this embodiment, depth integration is performed above 500m. Then, the integration results of the grid points inside the vortex at each time point are averaged in the vortex space to obtain the final average time series inside the vortex through depth integration and spatial averaging. Analyze the energy source and dissipation mechanism of the energy inside the vortex and the average time series inside the vortex of each dynamic item calculated quantitatively.

[0126] It is worth noting that the contents not elaborated in detail in the present invention are all prior art and are well known to those skilled in the art.

[0127] Therefore, the present invention provides a method for analyzing energy conversion of mesoscale eddies in the ocean. Through an adaptive detection algorithm with multi-scale dynamic constraints and coupled analysis of energy balance equations, it realizes the quantitative analysis of the energy conversion process within the life cycle of mesoscale eddies, improves the detection accuracy of weak amplitude and short-lived eddies, and systematically analyzes the energy exchange mechanism between eddies and background flows. It is suitable for eddy energy balance analysis and research on its impact on the climate system.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for analyzing ocean mesoscale eddy energy conversion, characterized in that: Here are the steps: Step S1, determining the basic characteristics of the target mesoscale vortex based on satellite remote sensing and observation data, downloading high-resolution gridded data with a temporal and spatial range larger than the estimated area, and performing data preprocessing; Step S2: Detect the target mesoscale vortex using a vortex detection algorithm to determine the center and boundary range of the vortex; Step S3: Based on the detection result in step S2, the target mesoscale vortex is tracked using a vortex tracking algorithm; Step S4: Calculate the vortex kinetic energy EKE and the vortex effective potential energy EPE using the high-resolution gridded data obtained in step S1; Step S5: quantifying the energy conversion process through the baroclinic conversion term T2 and the barotropic conversion term T4, and calculating the energy conversion between vortex energy and mean flow energy; Step S6: construct the kinetic energy budget equation to calculate the contributions of barotropic instability BTC, baroclinic conversion VEDF, wind stress input WW, pressure work PW and advection ADV to the vortex kinetic energy; Step S7: Generate a time series of each item through depth integration and spatial averaging to achieve quantitative calculation of vortex energy exchange.

2. A method for analyzing ocean mesoscale eddy energy conversion according to claim 1, characterized in that: In step S1, the range of the downloaded data needs to be slightly larger than the estimated range in both time and space scales, and the collected data is preprocessed and interpolated to the standard layer in depth.

3. A method for analyzing ocean mesoscale eddy energy conversion according to claim 2, characterized in that: In step S2, the specific steps of the vortex detection algorithm are: Step S21: Based on the sea surface height anomaly (SLA) data provided by the satellite altimeter, identify local maxima and local minima in the daily data snapshots through a 5×5 neighborhood search; Step S22: performing noise filtering on the extreme points, including: removing noise interference through a 3×3 neighborhood; verifying the validity of the extreme points through a 7×7 neighborhood; Step S23: Starting from the extreme point, the iterative threshold method is used to expand outward with an iterative step length of 0.05 cm to calculate the closed-loop contour line until the termination condition is met; Step S24, determining the vortex boundary by the reverse backtracking method; Step S25: retain the closed vortex structure with a spatial resolution of not less than 0.25°×0.25° and a grid number of ≥4.

4. The method for analyzing ocean mesoscale eddy energy conversion according to claim 3, wherein: In step S23 , the termination conditions include: a new extreme point appears in the closed-loop region; the number of iterations of the extreme point no longer increases; and the closed-loop contour line cannot continue to expand.

5. A method for analyzing ocean mesoscale eddy energy conversion according to claim 4, characterized in that: In step S3, the main steps of vortex tracking are: Step S31: Based on the Rossby phase velocity theory, the search range of vortex propagation is limited, and the nearest neighboring vortices in time and space are preferentially matched to construct the trajectory; Step S32: constraining the vortex matching conditions at adjacent times t and t+1 through attribute consistency check, including: controlling the vortex area change amplitude within the range of 0.25–2.75 times; The vortex amplitude variation was controlled within the range of 0.25–2.75 times; Step S33: For vortices that disappear for less than one day, insert virtual vortex nodes to maintain trajectory continuity, and use linear extrapolation to calculate the virtual node positions based on historical propagation speeds; Step S34: Eliminate virtual vortex nodes from the final trajectory data.

6. The method for analyzing ocean mesoscale eddy energy conversion according to claim 5, wherein: In step S4, the calculation method of the vortex kinetic energy EKE and the vortex effective potential energy EPE is as follows: Step S41: Extract the latitudinal and longitudinal components u and v of the horizontal flow field, and define the background field of the velocity component. The original flow velocity is decomposed by the change rate u' and v' during the vortex duration, and the calculation relationship of each parameter is as follows: Where u' is the rate of change of the latitudinal component of velocity, is the latitudinal component of the background velocity, v' is the rate of change of the longitudinal component of the velocity, is the meridional component of the background field velocity; Step S42, the calculation formula of the vortex kinetic energy EKE is as follows: Where ρ0 is the reference density; Step S43: Using the temperature, salinity, and pressure data of the seawater, the seawater density ρ(x, y, z, t) and the potential density ρ of the background field are calculated based on the seawater state equation UNESCO EOS-80. θ (z); The background density related to depth is obtained by spatial averaging over the study area and temporal averaging during the existence of the vortex, and the disturbance density is calculated as follows: in, is the perturbation density, ρ b (z) is the background density related to depth, x is the longitude coordinate, y is the latitude coordinate, z is the depth, and t is the time; Step S44: Calculate the effective potential energy of the vortex at each grid point within the vortex range using the following formula: Where g is the gravitational constant, is the rate of change of disturbance density, ρ is the density, is the background field potential density.

7. The method for analyzing ocean mesoscale eddy energy conversion according to claim 6, wherein: In step S5, the baroclinic conversion term T2 is calculated as follows: in, is the background field disturbance density; The calculation formula for the positive pressure conversion term T4 is as follows:

8. The method for analyzing ocean mesoscale eddy energy conversion according to claim 7, wherein: In step S6, a kinetic energy budget equation is constructed, and the formula is as follows: in, It represents the time rate of change of vortex kinetic energy; WW=u′τ′ x +v′τ′ y ; Where w' is the vertical velocity change rate, τ' x is the rate of change of wind stress component in the x direction, τ' y is the rate of change of wind stress component in y direction, and [' is the rate of change of sea water pressure.

9. The method for analyzing ocean mesoscale eddy energy conversion according to claim 8, wherein: Wind stress x-direction component τ x and the y-direction component τ y The calculation formula is as follows: t x =ρ·C d ·|U 10 |·u 10 ; t y =ρ·C d ·|U 10 |·v 10 ; Among them, U 10 is the wind speed at 10m above sea level, u 10 and v 10 are the wind speeds in the x and y directions of the wind field 10 m above the sea surface, C d is the drag coefficient, which is calculated as follows:

10. The method for analyzing ocean mesoscale eddy energy conversion according to claim 9, characterized in that: In step S7, the steps for calculating the time series of each item in the vortex are as follows: Step S71, determining the vortex inner grid point and the vortex outer grid point according to the vortex range at each time point obtained in step S3; Step S72: Select the depth within the vortex influence range and perform depth integration at the grid points within the vortex; Step S73: spatially average the grid integration results of the vortex at each time to obtain various time series.

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