A sea level fingerprint calculation method and system based on land component quality change

Abstract

The application provides a sea level fingerprint calculation method and system based on land component mass change, and belongs to the technical field of geodetic surveying; the method comprises the following steps: reconstructing a mass change time sequence of the land component according to obtained mass change data, performing grid processing on land and ocean areas in a data acquisition range, and mapping the mass change data to the grid; performing initial calculation of a sea level fingerprint based on the mass change data in the grid; and finally, iteratively optimizing the initial sea level fingerprint through parameter updating of the earth rotation inertia to obtain a final sea level fingerprint spatial distribution; the application can calculate corresponding gravitational potential and rotational potential based on the land mass change without relying on satellite observation, and can obtain an accurate sea level fingerprint spatial distribution through integral calculation in a global range.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geodesy, and particularly relates to a sea level fingerprint calculation method and system based on mass change of land components. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] At present, the Gravity Recovery and Climate Experiment (GRACE) and its successor (GRACE-FO) provide important observation data for global mass migration by monitoring the change of the Earth's gravity field. The existing technology relies on satellite data to invert the mass change of the ocean and land, and then analyzes the causes of sea level change.

[0004] However, such satellite observation-based technical means have obvious limitations, for example:

[0005] (1) Although satellite observation can reflect the independent contribution of different land components (such as Antarctic ice sheet, Greenland ice sheet, glaciers and land hydrology) to sea level change, it cannot reveal the unique spatial distribution characteristics of the sea level fingerprint (SLF) caused by each component. Moreover, satellite data processing itself is affected by factors such as spatial resolution, signal leakage, background model error, etc., which further limits its ability to identify the fine structure of regional SLF.

[0006] (2) The GRACE satellite was launched in 2002, resulting in a lack of direct observation data before 2002, making it difficult to construct a long-term and continuous mass change time series.

[0007] (3) GRACE satellite observation can only reveal mass change, but cannot reveal the vertical displacement change of the solid earth surface caused by redistribution of the earth's mass. SUMMARY

[0008] To overcome the shortcomings of the above-mentioned prior art, the present application provides a sea level fingerprint calculation method and system based on mass change of land components, which can establish a physical calculation model based on land mass change without relying on satellite observation, integrate the effects of gravity, rotation and land vertical displacement, calculate the corresponding gravitational potential and rotational potential, and perform integral calculation in the global range to obtain the accurate sea level fingerprint spatial distribution of relative sea level (ocean mass change), vertical displacement and absolute sea level.

[0009] To achieve the above-mentioned purpose, one or more embodiments of the present application provide the following technical solutions:

[0010] The application provides a sea level fingerprint calculation method based on mass change of land components.

[0011] The application provides a sea level fingerprint calculation method based on mass change of land components.

[0012] The mass change data of a plurality of land components in a preset time period is acquired, and data completion is performed; the mass change time sequence of the land components is reconstructed based on the mass change data after data completion.

[0013] The land and ocean areas in the data acquisition range are subjected to grid processing, and the mass change data of the land components is mapped to the corresponding grid.

[0014] The mass change data in the grid is used to perform initial calculation of the sea level fingerprint: the gravitational potential change and the rotational potential change of each unit grid in the global range caused by the mass change of each land component are calculated; the relative sea level change amount, the vertical displacement amount and the absolute sea level change amount at each grid point are determined according to the obtained gravitational potential change and the rotational potential change, and the initial sea level fingerprint corresponding to the land component is obtained.

[0015] The obtained initial sea level fingerprint is subjected to iterative optimization by updating the earth rotation inertia parameter after the redistribution of the earth mass, so that the final sea level fingerprint spatial distribution is obtained.

[0016] Further, the data completion includes: the data of the Antarctic ice sheet, the Greenland ice sheet and the glacier in the land components is subjected to data completion by using a quadratic fitting extrapolation method, and the land hydrology data in the land components is subjected to data completion by using a JPLmascon data package.

[0017] Further, the calculation of the gravitational potential change and the rotational potential change includes: first, the mass change data of the land components in the grid is subjected to initialization operation; subsequently, the mass exchange between the land and the ocean is subjected to function representation, and the gravitational potential component is determined by convolving all load points; meanwhile, the rotational potential component is determined based on the elastic rotational earth motion equation.

[0018] Further, the initialization operation includes: the land mass change is multiplied by the corresponding unit grid area, summed and divided by the sum of all ocean grid areas; meanwhile, the rotational inertia of the earth is set to be in an undisturbed initial state.

[0019] Further, the function representation of the mass exchange between the land and the ocean includes: the mass exchange between the land and the ocean is subjected to function representation by constructing a load function.

[0020] Further, the gravity potential component is determined by convolving all the load points, including: based on the sea level equation Green function, all the grids are convolved to determine the gravity potential component.

[0021] Further, the relative sea level change, the vertical displacement and the absolute sea level change all contain the influence of the gravity potential disturbance and the rotational potential disturbance.

[0022] The second aspect of the present application provides a sea level fingerprint calculation system based on the mass change of land components.

[0023] A sea level fingerprint calculation system based on the mass change of land components, comprising:

[0024] The mass change time sequence construction module is configured to: acquire mass change data of a plurality of land components in a preset time period, and perform data completion; and reconstruct the mass change time sequence of the land components based on the mass change data after data completion;

[0025] The gridding processing module is configured to: perform gridding processing on the land and ocean areas within the data acquisition range, and map the mass change data of the land components to the corresponding grids;

[0026] The initial sea level fingerprint calculation module is configured to: perform initial calculation of the sea level fingerprint based on the mass change data in the grids: calculate the gravity potential change and the rotational potential change of each unit grid in the global range caused by the mass change of each land component; determine the relative sea level change, the vertical displacement and the absolute sea level change at each grid point according to the obtained gravity potential change and the rotational potential change, and obtain the initial sea level fingerprint corresponding to the land component;

[0027] The sea level fingerprint iteration module is configured to: perform iterative optimization on the obtained initial sea level fingerprint by updating the earth rotation inertia parameter after the redistribution of the earth mass, to obtain the final sea level fingerprint spatial distribution.

[0028] The third aspect of the present application provides a computer readable storage medium, which stores a program, and the program is executed by a processor to realize the steps of a sea level fingerprint calculation method based on the mass change of land components according to the first aspect of the present application.

[0029] The fourth aspect of the present application provides an electronic device, comprising a memory, a processor and a program stored in the memory and executable on the processor, and the processor executes the program to realize the steps of a sea level fingerprint calculation method based on the mass change of land components according to the first aspect of the present application.

[0030] The above one or more technical solutions have the following beneficial effects:

[0031] (1) The present application carries out grid processing on the land and ocean areas within the data acquisition range, and maps the mass change data of the land component to the corresponding grid; then, based on the mass change data in the grid, the initial calculation of the sea level fingerprint is carried out. By griding the global land and sea areas, constructing the load function, and using the mass load forward theory, the sea level equation and the earth rotation theory, the changes of the gravitational potential and the rotation potential caused by each component are calculated respectively, and the high-resolution SLF is finally obtained through global integral iterative calculation. This method fundamentally avoids the problems of signal aliasing, leakage and model error existing in satellite gravity inversion, and can clearly reveal the wave-shaped gravitational potential component such as "melting source gravitational reduction causing seawater to move away from the melting source" and the circle-shaped rotation potential component such as "earth rotation causing seawater redistribution", thereby providing a SLF spatial feature analysis tool that is not dependent on satellite observation and more accurate and more mechanized than satellite observation.

[0032] (2) The present application carries out data completion on the mass change data of the land component obtained within the preset time period, that is, the data of the Antarctic ice sheet, the Greenland ice sheet and the glacier in the land component are completed by using the quadratic fitting extrapolation method, and the land hydrology data in the land component are completed by using the JPL mascon data package. Compared with the prior art, the present application breaks through the time limitation of gravity satellite observation, and can reconstruct the long-term and continuous mass change time series of each land component covering the satellite altimetry era.

[0033] (3) Based on the physical calculation model, the present application first calculates the gravitational potential disturbance and the rotation potential disturbance caused by the redistribution of the earth's surface mass, and then calculates the vertical displacement change of the solid earth surface related to the gravitational potential disturbance and the rotation potential disturbance. Compared with the prior art, the present application breaks through the limitation that the gravity satellite observation can only explain the mass change of the ocean, and can more accurately and systematically calculate the vertical displacement change of the solid earth surface caused by the redistribution of the earth's surface mass.

[0034] The advantages of the additional aspects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application.

[0036] Figure 1 The flowchart of the sea level fingerprint calculation method based on the mass change of the land component in the embodiment one of the present application.

[0037] Figure 2This is a time series diagram of the mass changes of four terrestrial components from 1993 to 2022 in Embodiment 1 of the present invention; wherein, Figure 2 (a) in the figure represents the time series diagram of the mass change of the Antarctic ice sheet. Figure 2 (b) in the figure represents the time series plot of mass change of the Greenland ice sheet. Figure 2 (c) in the figure represents the time series plot of mass change of mountain glaciers. Figure 2 (d) in the figure represents a time series plot of the quality changes in terrestrial hydrology. Detailed Implementation

[0038] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0039] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0040] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0041] Example 1

[0042] This embodiment discloses a sea level fingerprint calculation method based on changes in the mass of land composition.

[0043] like Figure 1 As shown, a sea level fingerprint calculation method based on changes in land composition mass includes:

[0044] Step S1: Obtain mass change data of multiple terrestrial components within a preset time period and complete the data; reconstruct the time series of mass changes of terrestrial components based on the completed mass change data;

[0045] Step S2: Grid the land and ocean areas within the data acquisition range, and map the mass change data of the land components to the corresponding grid.

[0046] Step S3: Perform initial calculation of sea level fingerprint based on mass change data within the grid: Calculate the gravitational potential change and rotational potential change on each unit grid globally caused by the mass change of each land component; determine the relative sea level change, vertical displacement, and absolute sea level change at each grid point based on the obtained gravitational potential change and rotational potential change, and obtain the initial sea level fingerprint corresponding to that land component.

[0047] Step S4, the obtained initial sea level fingerprint is iteratively optimized by updating the earth rotation inertia parameter after the redistribution of the earth mass, to obtain the final sea level fingerprint spatial distribution.

[0048] In the above process, based on the gridded land, ocean, and mass load forward theory, the present application calculates the disturbance of the gravity potential and rotational potential of the viscoelastic earth caused by the mass change of a certain specific land component, and further integrates all global grids using the sea level equation Green function and the elastic earth motion equation to calculate the unique spatial distribution characteristics of the SLF (sea level fingerprint) caused by the mass change of a certain specific land component. Thus, the present application can calculate the corresponding gravitational potential and rotational potential based on the mass change of the land without relying on satellite observations, and perform integral calculation in the global range to obtain the accurate sea level fingerprint spatial distribution. For the purpose of understanding the technical scheme of the present application, the specific implementation method in the technical scheme of the present application will be further explained and described below.

[0049] In step S1, the mass change data of a plurality of land components in a preset time period is obtained, and the data is completed; the mass change time series of the land components is reconstructed based on the mass change data after data completion.

[0050] The present application divides the global land into four parts, namely: Antarctic ice sheet AIS, Greenland ice sheet GrIS, mountain glacier Glacier and terrestrial hydrology TWS. Specifically, the mass change data of AIS and GrIS used in the present embodiment is from the historical data record of 1993-2020 provided by IMBIE organization. The Glacier data is calculated according to the reconstruction model proposed in 2020, and the TWS data is calculated by using the model constructed in 2019.

[0051] Further, the Glacier data includes two parts, the 1993-2018 glacier mass change dataset is from the website data provided by the statistical model trained by Malles & Marzeion based on historical data, and the 2019-2022 glacier mass change dataset is from the glacier mass change dataset obtained by the GlaMBIE organization based on joint observation statistics. The TWS data is from the GRACE-REC model constructed by Humphrey & Gudmundsson based on Grace data and meteorological data. The mass change time series of AIS and GrIS data has obvious mathematical rules, so a simple quadratic fitting extrapolation method is used to extend the three types of data to 1993-2022, that is, first construct a quadratic function of mass change and time from 1993 to 2022, and then use this quadratic function to extrapolate the AIS and GrIS mass change in 2021 and 2022; for the Glacier component, the global glaciers are divided into 17 glacier regions, and the mass change of each glacier region in 1993-2018 and 2019-2022 is obtained using the two datasets mentioned above. The TWS data time series changes irregularly, so the JPL provided GRACE / GFO monthly mascon (version: RL06.3_v04) is used to complete the complete TWS time series from 1993 to 2022. The GRACE-REC model reconstructed by Humphrey & Gudmundsson provides the global TWS change of the grid from 1993 to 2018 The JPL mascon dataset provides the global TWS change data of the grid from 2002 to now. This embodiment is based on the grid data provided by the GRACE-REC model, and the TWS change data of the grid point from 2019 to 2022 provided by the JPL mascon dataset is supplemented at each grid point. Thus, the complete time series of global TWS change from 1993 to 2022 is constructed.

[0052] As Figure 2 shown in the mass change time series of the four land components from 1993 to 2022 after completion, wherein, Figure 2 (a) of the GrIS mass change schematic diagram, Figure 2 (b) of the AIS mass change schematic diagram, Figure 2 (c) of the Glacier mass change schematic diagram, Figure 2 (d) of the TWS mass change schematic diagram. In Figure 2 , the horizontal axis represents the year, ranging from 1993 to 2022; the vertical axis represents the accumulated mass change since 1993, with the unit of Gt. From Figure 2It can be seen that the cumulative mass change of GrIS and AIS between 1993-2022 shows a relatively obvious quadratic function feature, and the melting speed gradually accelerates; the cumulative mass change of Glacier is relatively close to a straight line; the cumulative mass change of TWS is irregular, and maintains a mode of shock after a sharp decrease around 2000. Figure 2 It can also be seen that between 1993-2022, the ablation mass of Glacier is the largest, about 7000Gt; the ablation mass of GrIS is the second, about 5500Gt; the ablation mass of AIS and TWS is about 3000Gt and 2000Gt, respectively, ranking third and fourth.

[0053] In step S2, the land and sea areas in the data acquisition range are subjected to grid processing, and the mass change data of the land component is mapped to the corresponding grid.

[0054] The present application divides the land and sea in the global range into 22984 triangular grids, and the grid has a higher resolution on the land-sea boundary line, and a lower resolution on the single land and sea. In the embodiment, the triangular grid corresponding to each land component is selected, and the land mass change is divided by the total area of the grid and the ice height to obtain the equivalent ice height corresponding to the mass change, and the value is assigned to the selected grid. For TWS data, the difference method is used, and the value of the center point of the triangular grid obtained by difference is used as the input value of the triangular grid.

[0055] In step S3, the initial calculation of the sea level fingerprint is carried out based on the mass change data in the grid: the gravitational potential change and the rotational potential change of each unit grid in the global range caused by the mass change of each land component are calculated; the relative sea level change amount, the vertical displacement amount and the absolute sea level change amount at each grid point are determined according to the obtained gravitational potential change and rotational potential change, and the initial sea level fingerprint corresponding to the land component is obtained.

[0056] The calculation of the gravitational potential change and the rotational potential change includes: first, the mass change data of the land component in the grid is initialized; then, the mass exchange between the land and the sea is represented by a function, and the gravitational potential component is determined by convolving all the load points; at the same time, the rotational potential component is determined based on the elastic rotational earth motion equation. Specifically, the following method can be used:

[0057] Step S3-1, the mass change data of the land component in the grid is initialized.

[0058] ​First, the land mass change (expressed as equivalent water height) in the grid is multiplied by the corresponding unit grid area and summed, and then divided by the sum of all ocean grid areas (similar to the horizontal spread of the land mass change equivalent to the ocean), which is initialized to prepare for subsequent calculation of its spatial distribution characteristics.

[0059] Subsequently, the initial undisturbed state of the earth is set, i.e. the rotational inertia of the earth and the angular velocity of the earth's rotation are undisturbed.

[0060] Step S3-2, model calculation.

[0061] The land mass change causes mass exchange between land and ocean and mass redistribution on the earth's surface. First, the present invention defines a load function L to describe the mass exchange between land and ocean:

[0062] (1)

[0063] wherein, represents the ocean function, i.e. in the ocean area , in other areas . and represent the density of ice and the thickness change of ice, respectively, represent the density of seawater; represents the relative sea level value; , and represent the latitude, longitude and time of the point, respectively.

[0064] The mass change of the land component can cause both the relative sea level change (ocean mass change) and the vertical displacement of the solid earth surface. For a viscoelastic earth, the relationship between the relative sea level, the absolute sea level and the vertical displacement of the solid earth surface at a certain point on the earth's surface can be expressed as:

[0065] (2)

[0066] wherein, S represents the relative sea level value, N represents the absolute sea level value, U represents the vertical displacement of the solid earth surface.

[0067] Here the calculation method of N and U is given, and S can be obtained by the difference between the two. In equation (2) N, U both contain two terms, i.e. the gravitational potential component and the rotational potential component, which are calculated by the following formula:

[0068] (3)

[0069] (4)

[0070] where, g g represents the acceleration of gravity, and respectively represent the changes of gravitational potential and rotational potential caused by mass redistribution, and respectively represent the radial displacements of the solid earth surface caused by the gravitational potential and rotational potential perturbations. and respectively represent the spatial constants, which are defined as follows:

[0071] (5)

[0072] where, and respectively represent the density of ice and the density of water, R R represents the average radius of the earth, is the total area of the ocean, is the unit area of the earth surface. represents the change of ice thickness; represents the ocean function; represents the functions of gravitational potential, rotational potential, and vertical displacement, which can be represented as follows:

[0073] (6)

[0074] In formula (3) and (4), and are caused by the gravitational potential, and can be calculated by the Green function. The Green function and are defined by the following equations:

[0075] (7)

[0076] where, and represent the Love numbers, represents l the Legendre polynomial of order n, represents the arc length between the point to be solved on the earth surface and the load point.

[0077] Further, the gravitational potential components in formula (3) and formula (4) and can be obtained by the following integral formula:

[0078] (8)

[0079] where, The coordinates of the load point L It is the load function defined by equation (1). The grid area represents the load point. This represents the average density of the Earth.

[0080] Furthermore, the terms in equations (3) and (4) and It is caused by rotational potential and can be calculated using the following equation:

[0081] (9)

[0082] in, , This represents the second-order tidal Love number, specifically... The Love number represents the second-order tidal (potential energy). Represents the Love number for second-order tidal (displacement) events. Represents a second-order spherical harmonic function. Then it represents the spherical harmonic coefficients corresponding to the second-order spherical harmonic function.

[0083] To facilitate understanding, this embodiment will further explain the principle of rotational feedback.

[0084] In equation (9), The following formula can be used for calculation:

[0085] (10)

[0086] in, It is the Earth's average rotation speed. It is the Earth's average radius; a key variable. m i ( t It is dimensionless, and its calculation is as follows:

[0087] (11)

[0088] (12)

[0089] (13)

[0090] in, It is the Chandler oscillation frequency of the elastic Earth. Represents the polar moment of inertia. Chandler wobble frequency, representing the mean equatorial moment of inertia (elastic Earth). Represents the Chandler oscillation frequency (for a rigid Earth). It is the Earth's average rotation speed. It is a constant, representing the value of the previous epoch.

[0091] The physical meaning of is the amount of disturbance in the Earth's moment of inertia after the redistribution of its mass, that is:

[0092] (14)

[0093] (15)

[0094] (16)

[0095] in, Defined as , It represents the previous moment. This represents the Hevyside step function. It represents in After mass redistribution, moment of inertia The changes. In this example, When it is the initial time point, the definition is... .constant Set as the previous moment Value, that is: Then, the value for the next epoch is calculated using the formula described above. As epochs accumulate, the accumulation of rotational potential becomes increasingly apparent.

[0096] This represents the moment of inertia. Changes, The calculation is expressed by the following formula:

[0097] (17)

[0098] These are the second-order spherical harmonic coefficients of the load function (1). t Represents time.

[0099] Furthermore, the commonly used parameters employed in this embodiment throughout the calculation process are shown in Table 1.

[0100] Table 1 Commonly used parameters in the calculation process

[0101]

[0102] In step S4, the initial sea level fingerprint is iteratively optimized by updating the Earth's rotational inertia parameters after the redistribution of Earth's mass, so as to obtain the final spatial distribution of the sea level fingerprint.

[0103] Specifically, at the initial moment , it is considered that the earth's moment of inertia is not disturbed at all, i.e. it is considered that the constants in equations (11) =0. At the next time, first, the constants in equations (12), (13) are considered, and after the redistribution of the earth's mass, the corresponding moment of inertia disturbance values are calculated according to equations (15), (16), (17). According to the constants at this time and the disturbance values of the earth's moment of inertia at this time, and equations (12), (13), the at this time is calculated, and the rotational potential is updated to calculate the value at the next epoch, and so on, until the difference between the two epochs is less than the set threshold, and the loop is stopped.

[0104] Based on the above method, the present application can make up for the defects of the prior art relying on satellite observation data, and the present application can well show the unique global spatial distribution characteristics of the SLF corresponding to the mass change of each specific land component.

[0105] Embodiment Two

[0106] The embodiment discloses a sea level fingerprint calculation system based on mass change of land components.

[0107] A sea level fingerprint calculation system based on mass change of land components comprises:

[0108] The mass change time sequence construction module is configured to: acquire mass change data of a plurality of land components in a preset time period, and perform data completion; and reconstruct a mass change time sequence of the land components based on the mass change data after data completion.

[0109] The gridding processing module is configured to: perform gridding processing on land and ocean areas within a data acquisition range, and map the mass change data of the land components to corresponding grids.

[0110] The initial sea level fingerprint calculation module is configured to: perform initial calculation of a sea level fingerprint based on the mass change data in the grids: calculate gravitational potential change and rotational potential change on each unit grid in a global range caused by mass change of each land component; determine relative sea level change amount, vertical displacement amount and absolute sea level change amount at each grid point according to the obtained gravitational potential change and rotational potential change, and obtain an initial sea level fingerprint corresponding to the land component.

[0111] The sea level fingerprint iteration module is configured to: perform iterative optimization on the obtained initial sea level fingerprint by updating the earth's moment of inertia parameter after redistribution of the earth's mass, to obtain a final sea level fingerprint spatial distribution.

[0112] Embodiment Three

[0113] An object of the embodiment is to provide a computer-readable storage medium.

[0114] A computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method for calculating sea level fingerprint based on quality change of land component according to the embodiment one of the present disclosure.

[0115] Embodiment four

[0116] An object of the embodiment is to provide an electronic device.

[0117] An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for calculating sea level fingerprint based on quality change of land component according to the embodiment one of the present disclosure when executing the program.

[0118] The steps involved in the devices of the above embodiments two, three and four correspond to the method of the embodiment one, and the specific implementation can refer to the relevant description part of the embodiment one. The term "computer-readable storage medium" should be understood as including a single medium or multiple media of one or more instruction sets; it should also be understood as including any medium capable of storing, encoding or carrying instruction sets for execution by a processor and causing the processor to perform any of the methods of the present disclosure.

[0119] Those skilled in the art should understand that each module or step of the present disclosure described above can be realized by a general computer device, alternatively, they can be realized by program codes executable by a computing device, so that they can be stored in a storage device for execution by a computing device, or they can be respectively manufactured into each integrated circuit module, or a plurality of modules or steps among them can be manufactured into a single integrated circuit module to realize. The present disclosure is not limited to any specific combination of hardware and software.

[0120] The above describes the specific embodiments of the present disclosure in combination with the accompanying drawings, but is not a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present disclosure without inventive labor are still within the protection scope of the present disclosure.

Claims

1. A method for calculating sea level fingerprints based on changes in the quality of terrestrial components, characterized in that, The method comprises the following steps: acquiring mass change data of a plurality of land components within a preset time period and performing data completion; reconstructing a mass change time sequence of the land components based on the data-completed mass change data; performing grid processing on land and ocean regions within a data acquisition range and mapping the mass change data of the land components to corresponding grids; performing initial calculation of a sea level fingerprint based on the mass change data in the grids: calculating gravity potential change and rotational potential change of each unit grid caused by mass change of each land component on a global scale; determining relative sea level change, vertical displacement and absolute sea level change at each grid point according to the obtained gravity potential change and rotational potential change, and obtaining an initial sea level fingerprint corresponding to the land component; The calculation of the gravitational potential variation and the rotational potential variation includes: firstly, initializing the mass variation data of the land component in the grid; and then, representing the mass exchange between the land and the ocean by a function: wherein, represents the ocean function, i.e., in the ocean area , in other areas ; and respectively represent the density of ice and the thickness variation of ice, represents the density of seawater; represents the relative sea level value; , and respectively represent the latitude, longitude and time of the point, and the gravitational potential component is determined by convolving all the load points; the mass variation of the land component simultaneously causes the relative sea level variation and the vertical displacement of the solid earth surface, and for a viscoelastic earth, the relationship among the relative sea level, the absolute sea level and the vertical displacement of a specific point on the earth surface is represented as wherein, S represents the relative sea level value, N represents the absolute sea level value, U represents the vertical displacement of the solid earth surface; meanwhile, the rotational potential component is determined based on the elastic rotational earth motion equation; the initialization operation comprises: multiplying the land mass change by the corresponding unit grid area, summing up, and dividing by the sum of all ocean grid areas; at the same time, setting the moment of inertia of the earth as an undisturbed initial rotational state; iteratively optimizing the obtained initial sea level fingerprint by updating the moment of inertia parameter of the earth after redistribution of the earth mass to obtain a final spatial distribution of the sea level fingerprint.

2. A method for calculating sea level fingerprints based on changes in the quality of the terrestrial component as claimed in claim 1, characterized in that, The data completion comprises: using a quadratic fitting extrapolation method to complete data of the Antarctic ice sheet, the Greenland ice sheet and glaciers in the land components, and using a JPL mascon data package to complete data of land hydrological data in the land components.

3. A method for calculating sea level fingerprints based on changes in the quality of terrestrial components as claimed in claim 1, wherein, The mass exchange between the land and the ocean is represented by a function, which comprises: representing the mass exchange between the land and the ocean by a function through constructing a load function.

4. The method of claim 1, wherein, The gravity potential component is determined by convolving all load points, which comprises: convolving all grids based on a sea level equation Green function to determine the gravity potential component.

5. A method for calculating sea level fingerprints based on changes in the quality of terrestrial components as claimed in claim 1, wherein, The changes of the relative sea level change, the vertical displacement and the absolute sea level change all contain the effects of gravity potential disturbance and rotational potential disturbance.

6. A sea level fingerprinting system based on changes in quality of terrestrial components, characterized by, The method comprises the following steps: A mass change time sequence construction module is configured to acquire mass change data of a plurality of land components within a preset time period and perform data completion; reconstructing a mass change time sequence of the land components based on the data-completed mass change data; A grid processing module is configured to perform grid processing on land and ocean regions within a data acquisition range and map the mass change data of the land components to corresponding grids; An initial sea level fingerprint calculation module is configured to perform initial calculation of a sea level fingerprint based on the mass change data in the grids: calculating gravity potential change and rotational potential change of each unit grid caused by mass change of each land component on a global scale; determining relative sea level change, vertical displacement and absolute sea level change at each grid point according to the obtained gravity potential change and rotational potential change, and obtaining an initial sea level fingerprint corresponding to the land component; The calculation of the gravitational potential variation and the rotational potential variation comprises: firstly, initializing the mass variation data of the land component in the grid; and then, representing the mass exchange between the land and the ocean by a function: wherein, represents the ocean function, i.e. in the ocean region , in other regions ; and represent the density of ice and the thickness variation of ice respectively, represents the density of seawater; represents the relative sea level value; , and represent the latitude, longitude and time of the point respectively, and the gravitational potential component is determined by convolving all the load points; the mass variation of the land component simultaneously causes the relative sea level variation and the vertical displacement of the solid earth surface, and for a viscoelastic earth, the relationship among the relative sea level, the absolute sea level and the vertical displacement of a specific point on the earth surface is represented as wherein, S represents the relative sea level value, N represents the absolute sea level value, U represents the vertical displacement of the solid earth surface; meanwhile, the rotational potential component is determined based on the elastic rotational earth motion equation; the initialization operation comprises: multiplying the land mass change by the corresponding unit grid area, summing up, and dividing by the sum of all ocean grid areas; at the same time, setting the moment of inertia of the earth as an undisturbed initial rotational state; The sea level fingerprint iteration module is configured to iteratively optimize the obtained initial sea level fingerprint by updating the earth moment of inertia parameter after redistribution of the earth mass to obtain a final sea level fingerprint spatial distribution.

7. A computer-readable storage medium having stored thereon a program, characterized in that, The program, when executed by a processor, implements the steps of a method for calculating a sea level fingerprint based on a change in mass of a terrestrial component according to any one of claims 1-5.

8. An electronic device comprising a memory, a processor, and a program stored in the memory and capable of running on the processor, characterized by The program, when executed by a processor, implements the steps of a method for calculating a sea level fingerprint based on a change in mass of a terrestrial component according to any one of claims 1-5.

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