Ocean upwelling intensity observation and evaluation method

Abstract

The invention relates to the technical field of ocean new-generation information, and discloses an ocean upwelling intensity observation and evaluation method, which comprises the following steps: acquiring ocean profile observation data of a plurality of stations on a straight line observation section of a target area; processing the data to obtain profile distribution of potential temperature and potential density of each station; multi-point moving average is carried out on data of each station in the vertical direction, and noise and high-frequency signals are filtered out; drawing a distribution diagram of section salinity, potential temperature and potential density along with depth; marking isolines of the parameters; selecting an area with consistent isoline distribution, and calculating an included angle between the isoline and a horizontal line; and carrying out dimensionless processing on the included angle to obtain an evaluation index. According to the invention, under the condition of no network, on-site observation data of seawater temperature and salinity cross section are utilized to quantitatively evaluate the strength of seawater rising motion in one observation; if repeated observation is carried out for multiple times, the evaluation index can also give out the change characteristics of the upwelling intensity along with time, and guidance is provided for ship navigation decision making.

Description

Technical Field

[0001] The present invention relates to the field of new generation of marine information technology, specifically to measuring distance, level or azimuth, and particularly to an observation and evaluation method for the intensity of ocean upwelling. Background Art

[0002] Upwelling, also known as upwelling current, is a phenomenon in which the surface seawater at the sea surface diverges horizontally, causing the seawater below the surface to rise. In particular, if the surface seawater converges horizontally, causing the seawater to flow vertically downward from the sea surface, it is called downwelling. Upwelling and downwelling are collectively referred to as vertical currents and are important components of ocean circulation. Upwelling usually occurs in coastal areas. Due to the blowing of the wind, the surface seawater is pushed away from the coast, causing the sea surface to drop. To achieve hydrostatic equilibrium, deep seawater compensates and rises, forming an upwelling. Upwelling causes the isopycnal surface to tilt from a horizontal distribution towards the rising side. Upwelling actually corresponds to the vertical velocity of the fluid. The vertical flow direction is upward for upwelling and downward for downwelling.

[0003] Due to the too small vertical flow velocity of seawater, the flow velocity magnitude is usually less than 10 -3 m / s, generally about 10 -4 m / s. This flow velocity magnitude cannot be directly observed in actual ocean observations. Therefore, to describe the intensity of upwelling, several upwelling indices have been developed by predecessors, such as the wind stress index, the wind stress curl index, and even the intensity of upwelling can be defined by the anomaly value of the upwelling sea surface temperature. The specific definition is to use the coastal wind stress, wind stress curl, and the anomaly value of the sea surface temperature to represent the strength of upwelling. These methods are all indirect measures of the strength of upwelling.

[0004] The above indices have certain limitations in actual use. The above data requires data of a certain time length, and this data needs to be downloaded through the Internet, using the wind stress and other data as the data basis for evaluating the intensity of upwelling. In practice, ships are often in a network-free state and cannot use the Internet to download sea surface wind and sea surface temperature data. In the ocean, the ship's crew cannot perceive the intensity of the seawater rising movement, which is not conducive to various ships to carry out relevant decision-making and operations.

[0005] Currently, there is no method to measure the strength of the seawater rising movement in the ocean by only using one cross-section observation data. Therefore, it is necessary to develop a method for evaluating the intensity of ocean upwelling. In a network-free environment, ships can quickly evaluate the strength of the seawater rising movement in the sea area where they are located through the temperature and salinity profile observation data of several stations on a straight cross-section on the sea surface, and assist them in making corresponding decisions. Summary of the Invention

[0006] The object of the present invention is to provide a method for observing and evaluating the intensity of ocean upwelling, which uses numerical forms to quantitatively evaluate the strength of upwelling. By conducting multiple observations on this section, a time series of upwelling indices can be formed to quantitatively evaluate the strength changes of upwelling over time, and it can solve the technical problems of difficult quantitative calculation and evaluation of seawater upward movement.

[0007] To achieve the above object, the following technical solutions are adopted: A method for observing and evaluating the intensity of ocean upwelling, the method comprising: Obtaining ocean observation data at multiple stations on a straight section in the target area; wherein, the ocean observation data includes the whole-layer temperature of seawater and salinity profile data; Performing preliminary processing on the ocean observation data to obtain the profile distribution data of the potential temperature and potential density at each station; Performing multi-point moving average processing on the profile distribution data of the potential temperature and potential density at each station in the vertical direction to filter out noise and high-frequency signals, and obtaining filtered data; Based on the filtered data, drawing distribution diagrams of cross-section salinity, potential temperature, and potential density with depth; Based on the distribution diagrams of cross-section salinity, potential temperature, and potential density with depth, marking the isopleths of cross-section salinity, potential temperature, and potential density; Selecting an area with consistent isopleth distribution and calculating the angle between the isopleth and the horizontal line; Expressing the angle in degrees and dividing it by 90 degrees to perform non-dimensional unit removal processing, and obtaining an evaluation index for evaluating the intensity of upwelling.

[0008] Optionally, the straight section in the target area is a meridional section, a zonal section, or an observation section formed by connecting sea surface observation stations in a straight line.

[0009] Optionally, based on the evaluation index, the intensity of upwelling is evaluated in the following manner: When the evaluation index is greater than 0, there is upwelling on one side of the evaluation sea area; When the evaluation index is less than 0, there is downwelling on one side of the evaluation sea area; When the evaluation index is closer to 0 in the range of -1 to 1, the evaluated upwelling or downwelling is weak; When the evaluation index is closer to 1 in the range of -1 to 1, the evaluated upwelling is strong; When the evaluation index is closer to -1 in the range of -1 to 1, the evaluated downwelling is strong.

[0010] Optionally, selecting an area with consistent isopleth distribution and calculating the angle between the isopleth and the horizontal line includes: Select two seawater parcels of the same volume. The two seawater parcels are on the same isopleth and have the same seawater salinity, potential temperature, and potential density. The masses of the two seawater parcels are the same; Determine the potential energy of the seawater parcel through the following formula: mgh = mw 2 / 2; In the formula, m is the mass of the seawater parcel, g is the acceleration due to gravity, w is the vertical velocity of the seawater parcel, h is the lifting height; Based on the potential energy of the seawater parcel, the calculation formula for determining the vertical velocity of the seawater parcel is: ; Based on the calculation formula for the vertical velocity of the seawater parcel, calculate the lifting height when the vertical velocity of the seawater parcel is known h ; Based on the calculated lifting height h , calculate the angle between the isopleth and the horizontal line through the following formula: ; In the formula, is the angle between the isopleth and the horizontal line, is the horizontal distance between the two seawater parcels.

[0011] Optionally, calculate the potential temperature through the following formula: ; In the formula, , T is the observed seawater temperature, S is the observed seawater salinity, p is the observed seawater pressure data, is the potential temperature, is the vertical gradient of the seawater temperature.

[0012] Optionally, the method of performing multi-point moving average processing on the vertical profile distribution data of the potential temperature and potential density at each station includes performing 5-point, 7-point, or 9-point moving smoothing processing vertically.

[0013] Optionally, based on the filtered data, perform horizontal interpolation processing on the observed data at each observation station on the observation section according to the interpolated depth and horizontal distance. The horizontal resolution is 1 km, and draw the distribution diagrams of section salinity, potential temperature, and potential density with depth.

[0014] Optionally, the method for preliminarily processing the marine observation data to obtain the profile distribution data of the geopotential temperature and geopotential density at each station includes: interpolating the observation data at each observation station on the observation section in the horizontal direction, with a horizontal resolution of 1 km in the section direction.

[0015] Optionally, the absolute value of the angle between the isoline and the horizontal line is less than 90 degrees.

[0016] Optionally, the angular resolution of the angle between the isoline and the horizontal line is 0.1 degree.

[0017] Optionally, a more accurate evaluation method is adopted, and the angle between the isoline and the horizontal line at different stations on the section is calculated by the following formula i at: ; In the formula, is the angle between the isoline and the horizontal line at different stations i at, is the horizontal distance between two seawater parcels, and further more accurate evaluation details are given. is the height by which the seawater parcel at station i is lifted due to upward movement.

[0018] Optionally, for a sea area composed of multiple sections, the following formula is used to calculate different sections j , and the angle between the isoline and the horizontal line at different stations i at on the section: ; In the formula, is the angle between the isoline and the horizontal line at j section, i station, is the horizontal distance between two seawater parcels at j section, i station, is the height by which the seawater parcel at j section i station is lifted due to upward movement, and further more accurate evaluation details are given.

[0019] The beneficial effects of the present invention are: Based on the actual observed data of seawater temperature and salinity cross-sections, the present invention calculates the potential temperature and potential density. In the offline state without a network, by measuring the inclination angles of the isohalines, isopycnals, and isotherms of seawater salinity, potential temperature, and potential density on the cross-section, the maximum value of the three angles is selected as a parameter for evaluating the upwelling intensity, and the inclination angles are dimensionless processed to obtain the upwelling intensity index. The advantages of the present invention are that in the offline state of the ship, only using the observed data, calculating the dimensionless index of the isohaline inclination angle, quantitatively evaluating the intensity of the seawater upward movement for a single cross-section observation; multiple observations of the same cross-section can obtain the time series of the upwelling intensity change; and observing multiple cross-sections in a sea area can obtain the distribution of the upwelling intensity in that sea area. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. shows the flow chart of an observation and evaluation method for ocean upwelling intensity according to an embodiment of the present invention Figure 1 .

[0021] Figure 2 FIG. shows the flow chart of an observation and evaluation method for ocean upwelling intensity according to an embodiment of the present invention Figure 2 .

[0022] Figure 3 FIG. shows a schematic diagram of the working principle of an observation and evaluation method for ocean upwelling intensity according to an embodiment of the present invention; wherein w is the upward velocity of seawater parcel A1, is the seawater density, and the solid line is the isopycnal, h is the vertical lifting distance of seawater parcel A1 relative to A2 under the action of upward movement, l is the horizontal distance between seawater parcels A1 and A2, is the angle between the isohaline and the horizontal line, a is the horizontal auxiliary line, and b is the auxiliary line parallel to the inclined density line.

[0023] Figure 4 FIG. shows a schematic diagram of a calculation case of the upwelling intensity index on the east side according to an embodiment of the present invention, where (a), the distribution diagram of seawater potential temperature with depth; (b), the distribution diagram of seawater salinity with depth; (c), the distribution diagram of seawater potential density with depth. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0025] The following further describes in detail the specific embodiments of the present invention in conjunction with the accompanying drawings and embodiments.

[0026] Embodiment 1: Figure 1 The flowchart of an observation and evaluation method for the intensity of ocean upwelling according to an embodiment of the present invention is shown Figure 1 , as Figure 1 shown, an embodiment of the present invention provides an observation and evaluation method for the intensity of ocean upwelling. The observation and evaluation method for the intensity of ocean upwelling includes steps S10 to S70, which are introduced in detail as follows.

[0027] S10. Obtain ocean observation data at multiple stations on a straight cross-section in the target area; wherein, the ocean observation data includes the whole-layer seawater temperature and salinity profile data.

[0028] In this embodiment, the salinity profile data includes, but is not limited to, seawater salinity data and geopotential density data, and the whole-layer seawater temperature includes, but is not limited to, potential temperature data and seawater rapid temperature data.

[0029] In some embodiments, the straight cross-section in the target area is a meridional cross-section, a zonal cross-section, or an observation cross-section formed by connecting sea surface observation stations in a straight line.

[0030] In some embodiments, the length of the observation cross-section is 50 to 200 kilometers.

[0031] S20. Perform preliminary processing on the ocean observation data to obtain the profile distribution data of the potential temperature and geopotential density at each station.

[0032] In some embodiments, a station refers to an observation station, and the number of stations should be greater than or equal to three to ensure sufficient ocean observation data.

[0033] In some embodiments, the number of stations exceeds ten.

[0034] In some embodiments, the distance between each station is 2 to 20 kilometers.

[0035] S30. Perform multi-point moving average processing on the vertical profile distribution data of the potential temperature and potential density at each station to filter out noise and high-frequency signals, obtaining filtered data.

[0036] In some embodiments, the method of performing multi-point moving average processing on the vertical profile distribution data of the potential temperature and potential density at each station includes performing 5-point, 7-point, or 9-point moving smoothing processing vertically.

[0037] S40. Based on the filtered data, draw distribution diagrams of cross-sectional salinity, potential temperature, and potential density against depth.

[0038] In some embodiments, based on the filtered data, perform horizontal interpolation processing on the observation data at each observation station on the observation section according to the interpolated depth and horizontal distance, with a horizontal resolution of 1 km, and draw distribution diagrams of cross-sectional salinity, potential temperature, and potential density against depth.

[0039] S50. Based on the distribution diagrams of cross-sectional salinity, potential temperature, and potential density against depth, mark the isopleths of cross-sectional salinity, potential temperature, and potential density.

[0040] S60. Select regions with consistent isopleth distributions and calculate the angle between the isopleths and the horizontal line.

[0041] In some embodiments, selecting regions with consistent isopleth distributions and calculating the angle between the isopleths and the horizontal line includes: Select two seawater micro-masses of the same volume. The two seawater micro-masses are on the same isopleth, having the same seawater salinity, potential temperature, and potential density, and the masses of the two seawater micro-masses are the same; Determine the potential energy of the seawater micro-mass through the following formula: mgh = mw 2 / 2; In the formula, m is the mass of the seawater micro-mass, g is the acceleration due to gravity, w is the vertical velocity of the seawater micro-mass, h is the lifting height; Based on the potential energy of the seawater micro-mass, the calculation formula for determining the vertical velocity of the seawater micro-mass is: ; Based on the calculation formula for the vertical velocity of the seawater micro-mass, calculate the lifting height when the vertical velocity of the seawater micro-mass is known h ; Based on the calculated lifting height h , calculate the angle between the isopleth and the horizontal line through the following formula: ; In the formula, is the angle between the isotherm and the horizontal line, is the horizontal distance between two seawater parcels.

[0042] Optionally, the potential temperature is calculated by the following formula: ; In the formula, , T is the observed seawater temperature, S is the observed seawater salinity, p is the observed seawater pressure data, is the potential temperature, is the vertical gradient of the seawater temperature.

[0043] In some embodiments, for a more precise evaluation of different positions on a cross-section, the angle between the isotherm and the horizontal line at different stations i on the cross-section is calculated by the following formula: ; In the formula, is the angle between the isotherm and the horizontal line at different stations i , is the horizontal distance between two seawater parcels, thereby giving more precise evaluation details, is the height by which the seawater parcel at station i is lifted due to the upward movement.

[0044] In some embodiments, for a sea area composed of multiple cross-sections, the angles between the isotherm and the horizontal line at different cross-sections j , and at different stations i on the cross-section are calculated by the following formula: ; In the formula, is j the angle between the isotherm and the horizontal line at cross-section i , station is j the horizontal distance between two seawater parcels at cross-section i , station is the height by which the seawater parcel at cross-section j , station i is lifted due to the upward movement, thereby giving more precise evaluation details.

[0045] S70. Express the angle in degrees and divide it by 90 degrees to perform non-dimensional unit removal processing to obtain an evaluation index for evaluating the upwelling intensity.

[0046] In some embodiments, the absolute value of the angle between the isopleth and the horizontal line is less than 90 degrees. The angular resolution of the angle between the isopleth and the horizontal line is 0.1 degree.

[0047] In some embodiments, the way to perform the dimensionless unit-removing process is to represent the angle in radians, that is, divide by 90 degrees to obtain a radian value, and the range of this radian value is [-1, 1].

[0048] In some embodiments, based on the evaluation index, the upwelling intensity is evaluated in the following way: When the evaluation index is greater than 0, there is an upwelling on one side of the evaluation sea area; When the evaluation index is less than 0, there is a downwelling on one side of the evaluation sea area; When the evaluation index is closer to 0 in the range of -1 to 1, the upwelling or downwelling is evaluated as weak; When the evaluation index is closer to 1 in the range of -1 to 1, the upwelling is evaluated as strong; When the evaluation index is closer to -1 in the range of -1 to 1, the downwelling is evaluated as strong.

[0049] Embodiment 2: Figure 2 Shows the flow chart of an observation and evaluation method for ocean upwelling intensity according to an embodiment of the present invention Figure 2 , as Figure 2 shown, an embodiment of the present invention provides an observation and evaluation method for ocean upwelling intensity. The method includes: obtaining the whole-layer temperature and salinity profile data of multiple stations on a straight cross-section in the target area; performing preliminary processing on the ocean observation data to obtain the profile distributions of the potential temperature and potential density of each station; performing a 5-point moving average on the data of each station vertically to filter out noise and high-frequency signals; plotting the distribution diagrams of cross-section salinity, potential temperature, and potential density with depth; marking the isopleths of the above parameters; selecting the area with consistent isopleth distribution, calculating the angle between the isopleth and the horizontal line, and selecting the maximum angle of inclination of the isopleth among the salinity, potential temperature, and potential density parameters; the angle is represented in degrees and divided by 90 degrees for dimensionless unit-removing processing to obtain an evaluation index for evaluating the upwelling intensity. This observation and evaluation method for ocean upwelling intensity can directly use numerical quantification to evaluate the strength of the upwelling in a single observation from the cross-section observation data. If multiple observations are made, the evaluation index can also reflect the change in the upwelling intensity.

[0050] In this embodiment, the upwelling intensity is evaluated according to the inclination angles of the isohalines, isopycnals, and potential temperature with depth. If the inclination angle of the isohaline on the section is the largest, the upwelling area is mainly controlled by the seawater salinity, and the input value of exogenous fresh water is relatively large; if the inclination angle of the isopycnal on the section is the largest, the upwelling process is mainly controlled by the seawater temperature, and the input value of exogenous fresh water is relatively small; if the inclination angle of the isopycnal on the section is the largest, the upwelling process is mainly controlled by the seawater density and jointly controlled by the seawater temperature and salinity.

[0051] In some embodiments, a rapid temperature observation profile obtained from only one cross-section observation can also be used to establish an upwelling intensity evaluation parameter based on seawater temperature, providing an upwelling intensity evaluation index for ships far from land that cannot sense the upwelling or downwelling state of the seawater in the sea area where the ship is located, and providing a basis and reference for ship decision-making.

[0052] As Figure 3 shown, it is a schematic diagram of the working principle of the observation and evaluation method for ocean upwelling intensity. Due to the upwelling movement of the seawater on the left side of the section, the seawater hydrological parameters, such as the seawater potential density , the isohaline rises, and the rising height of the seawater potential density is h . The hydrological parameters include seawater salinity, potential temperature, and potential density. Take seawater parcels of the same volume. To distinguish the two seawater parcels, Figure 2 A1 and A2 are used to represent the two seawater parcels in l . The horizontal distance between the two seawater parcels is m . Since the isohalines are the same, the seawater salinity, potential temperature, and potential density of the two parcels are the same, that is, the masses m of the two seawater parcels are the same. The result of the upwelling movement causes the gravitational potential energy of the seawater parcel A1 to rise, and the potential energy increases by mgh , where g is the acceleration due to gravity. The upward kinetic energy of the seawater parcel is mw 2 / 2. The increase in the potential energy of the seawater parcel is the conversion of its kinetic energy. Therefore, mgh = mw 2 2 / 2; In the formula, w is the vertical velocity of the seawater parcel.

[0053] The expression for the vertical velocity of the seawater parcel can be obtained from the above formula as: ; The angle of the upwelling movement of the fluid parcel that causes the isohaline to rise is the angle between the isopycnal and the horizontal line, which is calculated by the following formula: ; In the formula, is the angle between the isopleth and the horizontal line. In a simplified case, by means of the horizontal auxiliary line a and the auxiliary line b parallel to the inclined isopycnals, measuring the angle between the two lines can quickly obtain the angle parameter.

[0054] In an exemplary embodiment, a specific example of an observation and evaluation method based on the intensity of ocean upwelling is given. This specific example takes the seawater temperature, salinity, and density section observed by a ship on the east side of Hainan Province as an example to evaluate the intensity of the upwelling. As Figure 4 shown, the left side of the observation section is close to the land, the right side of the observation section is close to the open sea, the bottom part is the seabed, the horizontal axis is the distance from the coast, and the vertical axis is the distribution of the observed hydrological parameters (seawater potential temperature, seawater salinity, seawater potential density) with depth. The ship observed the hydrological parameter profiles at 15 stations on this section.

[0055] Since the distribution of the isopycnals is relatively consistent, a single angle is used here to evaluate the intensity of the upwelling during the observation period. Combining Figure 2 , this specific example is implemented by the following steps 1 to 12.

[0056] Step 1, Selection of the observation section: Draw a straight line on the nautical chart. The length of the straight line should be 50 km to 200 km. The straight line can be in the meridional direction, zonal direction, or any direction. For example, near the continental shelf, the straight line should be perpendicular to the shoreline or perpendicular to the isobaths.

[0057] Step 2, Obtaining the observation stations: On the above-selected observation section, select about 10 stations, and the station spacing is 5 km to 20 km.

[0058] Step 3, Obtaining the observation data: At the above-selected observation stations, use instruments to quickly obtain the distribution data of seawater temperature and salinity with depth at the stations.

[0059] Step 4, Calculation of potential hydrological parameters: For the seawater temperature and seawater salinity observed at each observation station on the above observation section, calculate the potential temperature and potential density. The calculation method of the potential temperature is as follows: ; In the formula, , T is the observed seawater temperature, S is the observed seawater salinity, p is the observed seawater pressure data, is the potential temperature, is the vertical gradient of the seawater temperature.

[0060] Step 5. Vertical interpolation of potential hydrological parameters: Linearly interpolate the seawater salinity, potential temperature, and potential density of each of the above observation stations in the vertical direction. The processed data are evenly spaced in the vertical direction, and the general spacing should be 1 meter, or one hundredth of the total observation depth.

[0061] Step 6: Vertical Sliding Average of Potential Hydrological Parameters: Perform a vertical sliding average of the vertically interpolated seawater salinity, geopotential temperature, and geopotential density at each observation station. This sliding average is typically performed over five points, but can also be performed over seven or nine points. The specific number of sliding averages depends on the water depth. Deeper waters require more sliding averages, while shallower waters require fewer.

[0062] Step 7. Horizontal interpolation of the cross section: Interpolate the above observation stations in the horizontal direction with a horizontal resolution of 1 km and interpolate the corresponding hydrological parameters.

[0063] Step 8: Draw the distribution of hydrological parameters along the cross section with depth: Draw the contour line cross section of the above observation data, as shown in the following example: Figure 4 The seawater potential temperature ( Figure 4 (a)), seawater salinity ( Figure 4 (b)), seawater potential density ( Figure 4 c) Contour map.

[0064] Step 9: Divide the above motion diagnosis range: for the seawater potential temperature to be diagnosed ( Figure 4 (a)), seawater salinity ( Figure 4 (b)), seawater potential density ( Figure 4 In (c), the scope of diagnosis is divided according to actual needs, such as Figure 4 , divided into three areas: A, B and C.

[0065] If a more accurate angle is required, the angles of adjacent stations can be solved to obtain the distribution of the angle of upwelling intensity on the horizontal section.

[0066] Step 10, measuring the contour angle: the seawater potential temperature in the above-mentioned A, B, and C areas ( Figure 4 (a)), seawater salinity ( Figure 4 (b)), seawater potential density ( Figure 4 For the contour lines in (c), measure the inclination angle of the contour lines. For example, to assess the inclination of the contour lines in Area B toward the shelf, select the horizontal auxiliary line (dashed line) and measure the angle of the contour lines in Area B relative to the horizontal auxiliary line. Rotate the horizontal auxiliary line counterclockwise to obtain the angle of the contour line. An angle of 45° is considered positive when rotated counterclockwise. The left side of Area B indicates upward movement.

[0067] Similarly, it can be obtained that there is basically no upward movement in area A. In area C, due to the angle of the isopleth being 5°, the upward movement is much smaller than that of the seawater in area B.

[0068] Step 11. Nondimensionalize the upwelling index: Divide the above angle value by 90°. Then the upwelling index of area B is 0.5, that of area A is 0, and that of area C is 0.05.

[0069] If a more refined assessment of the upwelling index is required, the upwelling index can be calculated at different depths and even at different horizontal distances.

[0070] Step 12. Time series of the upwelling index: For the same sea area, multiple cross-section observations are carried out, and a time series of the upwelling index can be obtained.

[0071] It should be noted that when drawing the isopleth map of the hydrological parameters for multiple cross-section observations, the scales of the horizontal axis and the vertical axis should be kept the same.

[0072] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the patent protection scope of the present invention shall be defined by the claims.

Claims

1. An observation and evaluation method for the intensity of ocean upwelling, characterized in that, The method includes: Obtaining marine observation data at multiple stations on a straight cross-section in the target area; wherein, the marine observation data includes the integrated seawater temperature and the salinity profile data; Performing preliminary processing on the marine observation data to obtain the profile distribution data of the potential temperature and potential density at each station; Performing multi-point moving average processing on the profile distribution data of the potential temperature and potential density at each station in the vertical direction to filter out noise and high-frequency signals, and obtaining filtered data; Based on the filtered data, plotting the distribution diagrams of cross-section salinity, potential temperature, and potential density versus depth; Based on the distribution diagrams of cross-section salinity, potential temperature, and potential density versus depth, marking the isopleths of cross-section salinity, potential temperature, and potential density; Selecting an area with consistent isopleth distribution and calculating the angle between the isopleth and the horizontal line; Expressing the angle in degrees and dividing it by 90 degrees to perform dimensionless processing to remove the data unit, and obtaining an evaluation index for evaluating the upwelling intensity; 2. The observation and evaluation method for ocean upwelling intensity according to claim 1, wherein The straight cross-section in the target area is a meridional cross-section, a zonal cross-section, or an observation cross-section formed by connecting marine observation stations in a straight line; 3. The method for observing and evaluating the intensity of ocean upwelling according to claim 1, wherein Based on the evaluation index, the upwelling intensity is evaluated in the following manner: When the evaluation index is greater than 0, there is an upwelling on one side of the evaluation sea area; When the evaluation index is less than 0, there is a downwelling on one side of the evaluation sea area; When the evaluation index is closer to 0 in the range of -1 to 1, the upwelling or downwelling is weak; When the evaluation index is closer to 1 in the range of -1 to 1, the upwelling is strong; When the evaluation index is closer to -1 in the range of -1 to 1, the downwelling is strong; 4. The method for observing and evaluating the intensity of ocean upwelling according to claim 1, characterized in that, Selecting an area with consistent isopleth distribution and calculating the angle between the isopleth and the horizontal line, including: Selecting two seawater micro-masses with the same volume. The two seawater micro-masses are on the same isopleth, have the same seawater salinity, potential temperature, and potential density, and the masses of the two seawater micro-masses are the same; Determining the potential energy of the seawater micro-mass through the following formula: mgh = mw 2 / 2； In the formula, m is the mass of the seawater parcel, g is the acceleration due to gravity, w is the vertical flow velocity of the seawater parcel, h is the lifting height; Based on the potential energy of the seawater micro-mass, determining the calculation formula for the vertical flow velocity of the seawater micro-mass; ； Based on the calculation formula of the vertical velocity of the seawater parcel, the uplift height is calculated when the vertical velocity of the seawater parcel is known. h ; Based on the calculated lift height h , calculate the angle between the isoline and the horizontal line through the following formula: ； Wherein, is the included angle between the isopleth and the horizontal line, is the horizontal distance between two seawater parcels.

5. The method for observing and evaluating the intensity of ocean upwelling as claimed in claim 1, wherein Calculating the potential temperature through the following formula; ； wherein, , T is the observed seawater temperature, S is the observed seawater salinity, p is the observed seawater pressure data, is in degrees Celsius, is the vertical gradient of seawater temperature.

6. The observation and evaluation method for the intensity of ocean upwelling as described in claim 1, characterized in that, The method of performing multi-point moving average processing on the profile distribution data of the potential temperature and potential density at each station in the vertical direction includes performing 5-point, 7-point, or 9-point moving smoothing processing in the vertical direction; 7. The method for observing and evaluating the intensity of ocean upwelling according to claim 1, wherein Based on the filtered data, performing horizontal interpolation processing on the observation data of each observation station on the observation cross-section according to the interpolated depth and horizontal distance in the cross-section direction, with a horizontal resolution of 1 km, and plotting the distribution diagrams of cross-section salinity, potential temperature, and potential density versus depth; 8. The method for observing and evaluating the intensity of ocean upwelling according to claim 1, wherein The method of performing preliminary processing on the marine observation data to obtain the profile distribution data of the potential temperature and potential density at each station includes: performing horizontal interpolation processing on the observation data of each observation station on the observation cross-section in the cross-section direction, with a horizontal resolution of 1 km.

9. The method for observing and evaluating the intensity of ocean upwelling according to claim 1, characterized in that, Calculate the angle between the contour line and the horizontal line at different stations on the cross-section through the following formula i as follows: ； In the formula, is the included angle between the isoline and the horizontal line at different stations, i is the horizontal distance between two seawater parcels, is the station, i is the height by which the seawater parcel at the station is lifted due to the upward movement.​ 10. The method for observing and evaluating the intensity of ocean upwelling as described in claim 1, characterized in that, For a sea area composed of multiple cross-sections, the angles between the isopleths and the horizontal line at different cross-sections j and different stations of the cross-section i are calculated through the following formula: ； In the formula, is j the cross-section, i the angle between the isopleth and the horizontal line at the station, j is i the horizontal distance between two seawater parcels at the cross-section j station position i and the height by which the seawater parcel is lifted due to upward movement at the

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