Method for quantifying upwelling intensity and biogeochemical process thereof based on hydrogen and oxygen isotopes

Abstract

The invention discloses a method for quantifying upwelling intensity and biogeochemical process thereof based on hydrogen and oxygen isotope, which comprises the following steps: acquiring hydrological information and hydrogen and oxygen isotope value of a target sea area, and establishing a hydrogen and oxygen isotope mass balance model; based on a hydrogen and oxygen isotope mass balance model, calculating the proportion of different source water bodies in the upwelling affected zone of the target sea area, and obtaining the contribution of deep water to the upwelling affected zone; estimating the theoretical nutritive salt concentration of the upwelling affected zone based on the nutritive salt concentrations of the original surface water and the upwelling source deep water and the contribution of the deep water to the upwelling affected zone; and comparing the actually measured upwelling affected zone nutritive salt concentration with the theoretical nutritive salt concentration to obtain the contribution of the biological process of the target sea area. Based on the advantage that hydrogen and oxygen isotopes in water are tracers of water, a method for quantifying the upwelling intensity and the biogeochemical process of the upwelling intensity is developed, and a new technical method is provided for scientifically and quantitatively evaluating an upwelling ecological system.

Description

Technical Field

[0001] The present invention relates to the technical field of coupling and simulation of upwelling and marine biogeochemical processes, and in particular to a method for quantifying upwelling intensity and its biogeochemical processes based on hydrogen and oxygen isotopes. Background Art

[0002] Upwelling refers to the upward movement of water bodies and is an important part of ocean circulation. Upwelling brings rich nutrients to the upper water bodies and has a significant promoting effect on marine primary production. Strong upwelling areas are characterized by low temperature, high salinity, high nutrients, and high primary productivity, and often form good fishing grounds (such as the famous Peruvian fishing grounds). my country's East China Sea and South China Sea have many coastal upwelling areas. Quantitative analysis of upwelling intensity and its impact on marine biogeochemistry is of great significance to fisheries and marine ecological environment.

[0003] However, the limitations of traditional methods restrict scholars' specific understanding of the quantitative characteristics and intensity of upwelling. Traditionally, temperature and salinity have long been used to indicate upwelling, and this method is still widely used. However, this method has limitations because temperature and salinity are not conservative and are not tracers of the water itself. Especially in the offshore ocean, the difference in salinity between the surface, subsurface and deep water bodies is relatively small, and it cannot indicate the existence of upwelling. Hydrogen and oxygen isotopes (δD and δ 18 O) composition varies greatly, for example, the δD and δ 18 O values ​​tend to be low. Therefore, δD and δ 18 O can be used to trace upwelling, and δD and δ 18 O combined with temperature and salinity can make up for the shortcomings of traditional methods. 18 The advantage of O is its conservativeness. It is a tracer of water itself. The δD and δ 18 O values ​​tend to vary more, because runoff, precipitation, evaporation, and upwelling of high-salinity deep water all affect the isotopic composition of water. Therefore, whether near the coast or in the open ocean, there are obvious isotopic differences between surface, subsurface, and deep waters, and based on these characteristics, the strength of global ocean upwelling can be well quantified.

[0004] In summary, the traditional temperature-salinity method still has limitations in tracing upwelling, and it is difficult to quantify the intensity of upwelling and its biogeochemical processes. Therefore, a method based on water hydrogen and oxygen isotope technology to quantify the intensity of upwelling and its biogeochemical processes is urgently needed to solve this problem. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned prior art, the present invention proposes a method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes. According to the differences in hydrogen and oxygen isotopes of water at different depths and in different regions, the upwelling intensity is quantified through the hydrogen and oxygen isotope mass balance model, which provides a new technical method for quantitatively analyzing the impact of upwelling on marine biogeochemical processes.

[0006] To achieve the above object, the present invention provides a method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes, comprising:

[0007] Obtain hydrological information and hydrogen and oxygen isotope values ​​of the target sea area and establish a hydrogen and oxygen isotope mass balance model;

[0008] Based on the hydrogen and oxygen isotope mass balance model, the proportion of water bodies from different sources in the upwelling influence area of ​​the target sea area is calculated to obtain the contribution of deep water to the upwelling influence area;

[0009] Estimate the theoretical nutrient concentration in the upwelling affected area based on the nutrient concentration of the original surface water and the deep water in the upwelling source area and the contribution of the deep water to the upwelling affected area;

[0010] The measured nutrient concentration in the upwelling influence zone is compared with the theoretical nutrient concentration to obtain the contribution of the biological process in the target sea area.

[0011] Preferably, establishing the hydrogen and oxygen isotope mass balance model comprises:

[0012] Obtaining the hydrological information and hydrogen and oxygen isotope values;

[0013] The upwelling influence area is identified and differentiated through the relationship between temperature, salinity and water hydrogen and oxygen isotopes, and the differentiation results are obtained;

[0014] Identifying the differentiation results to form different water masses of the upwelling mixed water body, and determining the hydrogen and oxygen isotope values ​​of different end-member waters based on the hydrological information and the hydrogen and oxygen isotope values;

[0015] The isotope mass balance model is established based on the different water masses of the upwelling mixed water body and the hydrogen and oxygen isotope values ​​of the upwelling influence zone.

[0016] Preferably, obtaining hydrological information of the target sea area includes:

[0017] The hydrological information is obtained by using CTD detection, wherein the survey time is the season when the upwelling influence is obvious.

[0018] Preferably, obtaining the hydrogen and oxygen isotope values ​​of the target sea area includes:

[0019] In the target sea area, a Niskin water sampler is used to obtain seawater from different layers. When obtaining seawater, the seawater is exposed to air for the same length of time, filled and sealed in glass bottles, and then the hydrogen and oxygen isotope values ​​of the seawater are measured using a gas stable isotope ratio mass spectrometer within a fixed time period.

[0020] Preferably, identifying and distinguishing the upwelling influence area through the relationship between temperature, salinity and water hydrogen and oxygen isotopes includes:

[0021] Determine the surface water in the upwelling affected area, the surface water in the non-upwelling affected area, and the deep water in the upwelling affected area based on the plane distribution map and cross-sectional distribution map of the temperature, salinity, and water hydrogen and oxygen isotopes in the target sea area;

[0022] The surface water in the upwelling influence zone is formed by mixing the surface water in the non-upwelling influence zone and the deep water in the upwelling influence zone.

[0023] Preferably, the isotope mass balance model is:

[0024] X h =f b ×X b +f s ×X s ;

[0025] f b +f s =1;

[0026] Where, X h is the average value of hydrogen isotopes or oxygen isotopes in the surface water in the upwelling zone; X b is the average value of hydrogen isotope or oxygen isotope of surface water in the non-upwelling area; X s is the average value of hydrogen isotopes or oxygen isotopes in the deep water in the upwelling zone; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

[0027] Preferably, according to the law of nutrient mass balance in the physical mixing process, the theoretical nutrient concentration in the upwelling influence area is quantitatively estimated, specifically:

[0028] Y h =f b ×Y b +f s ×Y s ;

[0029] Where Y h is the theoretical estimated value of the nutrient concentration in the surface water of the upwelling area; Y b Y is the average nutrient concentration of the surface layer in the non-upwelling area;s is the average nutrient concentration of deep water in the upwelling area; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

[0030] Preferably, comparing the measured nutrient concentration of the upwelling influence area with the theoretical estimated value of the nutrient concentration of the surface water in the upwelling influence area comprises:

[0031] The average value of the measured nutrient concentration in the upwelling influence area is recorded as Z h ;

[0032] If (Y h -Z h ) / Y h ≤ the preset threshold, it is considered that the physical process in the upwelling influence area is dominant and the influence of biological processes can be ignored;

[0033] If (Y h -Z h ) / Y h ≥ the preset threshold, it is considered that the upwelling influence area has an impact on the biological process.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] Based on the advantage that water hydrogen and oxygen isotopes are tracers of water itself, the present invention develops a method to quantify the intensity of upwelling and its biogeochemical processes, providing a new technical method for scientific quantitative evaluation of upwelling ecosystems; by establishing an isotope mass balance model, the proportion of water bodies from different sources in the upwelling impact zone can be accurately calculated, and the specific contribution of deep water to the upwelling impact zone can be clarified. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 This is a flow chart of a method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0040] The present invention proposes a method for quantifying upwelling intensity and its biogeochemical processes based on hydrogen and oxygen isotopes, such as Figure 1 ,include:

[0041] Obtain hydrological information and hydrogen and oxygen isotope values ​​of the target sea area and establish a hydrogen and oxygen isotope mass balance model;

[0042] Based on the hydrogen and oxygen isotope mass balance model, the proportion of water bodies from different sources in the upwelling impact zone of the target sea area is calculated to obtain the contribution of deep water to the upwelling impact zone;

[0043] Estimate the theoretical nutrient concentration in the upwelling affected area based on the nutrient concentrations of the original surface water and deep water in the upwelling source area and the contribution of deep water to the upwelling affected area;

[0044] The measured nutrient concentrations in the upwelling impact zone are compared with the theoretical nutrient concentrations to obtain the contribution of biological processes in the target sea area.

[0045] Furthermore, establishing a hydrogen and oxygen isotope mass balance model includes:

[0046] Obtain hydrological information and hydrogen and oxygen isotope values ​​of the target sea area;

[0047] The upwelling influence area is identified and differentiated through the relationship between temperature, salinity and water hydrogen and oxygen isotopes, and the differentiation results are obtained;

[0048] Identify the differentiation results to form different water masses of the upwelling mixed water body, and determine the hydrogen and oxygen isotope values ​​of different end-member waters based on hydrological information and hydrogen and oxygen isotope values;

[0049] The isotope mass balance model is established based on the different water masses of the upwelling mixed water body and the hydrogen and oxygen isotope values ​​of the upwelling influence zone.

[0050] Specifically, obtaining hydrological information of the target sea area includes:

[0051] The hydrological information is obtained by using CTD detection during the field investigation. In this embodiment, the investigation time is the season when the upwelling influence is obvious.

[0052] Obtaining the hydrogen and oxygen isotope values ​​of the target sea area includes:

[0053] In the target sea area, a Niskin water sampler is used to obtain seawater from different layers. When obtaining, the seawater is exposed to the air for the same length of time (in this embodiment, the contact with the air does not exceed 1 minute), filled with glass bottles and sealed, and then the hydrogen and oxygen isotope values ​​of the seawater are measured using a gas stable isotope ratio mass spectrometer within a fixed time period (within one month).

[0054] Furthermore, the upwelling influence area can be identified and differentiated through the relationship between temperature, salinity and water hydrogen and oxygen isotopes, including:

[0055] Determine the surface water in the upwelling affected area, the surface water in the non-upwelling affected area, and the deep water in the upwelling affected area based on the plane distribution map and cross-sectional distribution map of the temperature, salinity, and water hydrogen and oxygen isotopes in the target sea area;

[0056] The surface water in the upwelling influence area is formed by mixing the surface water in the non-upwelling influence area and the deep water in the upwelling influence area.

[0057] Specifically, the isotope mass balance model is:

[0058] X h =f b ×X b +f s ×X s ;

[0059] f b +f s =1;

[0060] Where, X h is the average value of hydrogen isotopes or oxygen isotopes in the surface water in the upwelling zone; X b is the average value of hydrogen isotope or oxygen isotope of surface water in the non-upwelling area; X s is the average value of hydrogen isotopes or oxygen isotopes in the deep water in the upwelling zone; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

[0061] Furthermore, according to the law of nutrient mass balance in the physical mixing process, the theoretical nutrient concentration of the surface water in the upwelling area is quantitatively estimated by using the nutrient concentration of the surface water in the non-upwelling area and the deep water in the upwelling area and their contribution to the upwelling area. Specifically,

[0062] Y h =f b ×Y b +f s ×Y s ;

[0063] Where Y his the theoretical estimated value of the nutrient concentration in the surface water of the upwelling area; Y b Y is the average nutrient concentration of the surface layer in the non-upwelling area; s is the average nutrient concentration of deep water in the upwelling area; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

[0064] Furthermore, the measured nutrient concentration in the upwelling affected area is compared with the theoretical estimated value of the nutrient concentration in the surface water of the upwelling affected area. If the difference between the two is small, it means that the physical process is dominant; if the theoretical value is significantly lower than the measured value, it means that the upwelling promotes the primary production of phytoplankton. The contribution of biological processes can be quantitatively estimated based on the difference between the theoretical value and the measured value.

[0065] Specifically, the average value of the measured nutrient concentration in the upwelling influence area is recorded as Z h ;

[0066] If (Y h -Z h ) / Y h ≤10%, it is considered that the physical process in the upwelling area is dominant and the influence of biological processes can be ignored; if (Y h -Z h ) / Y h If ≥10%, it is considered that the upwelling has some influence on the biological processes in the affected area.

[0067] By adopting the method of this embodiment, upwelling at different stages can be investigated and quantitatively analyzed separately, and the contribution of deep water to upwelling and the biological response at different stages can be obtained.

[0068] The present invention can accurately calculate the proportion of water bodies from different sources in the upwelling influence zone by establishing an isotope mass balance model, and clarify the specific contribution of deep water to the upwelling influence zone.

[0069] The present invention can quantitatively analyze the intensity of upwelling and its impact on marine biogeochemical processes, thus providing a scientific basis for the assessment and management of fishery resources. By understanding the changes in nutrients brought about by upwelling and the response of biological processes, the distribution and change trends of fishery resources can be more accurately predicted, reasonable fishing strategies can be formulated, and sustainable utilization of fishery resources can be achieved.

[0070] This invention combines hydrogen and oxygen isotope technology with oceanographic research, providing new ideas and methods for marine science research. This interdisciplinary innovative method can more comprehensively and deeply study complex processes such as ocean circulation and material transport, expand the depth and breadth of oceanographic research, and provide new perspectives and tools for solving other difficult problems in the field of marine science.

[0071] In order to more clearly express the technical solution of the present invention, the following specific embodiments are provided to introduce the solution:

[0072] Embodiment 1

[0073] Spring coastal upwelling in western Guangdong:

[0074] Step 1: In May 2018 (spring), five sections with a total of 33 stations were arranged in the range of 20.0-21.5°N and 110.0 and 112.0°E in the coastal waters of western Guangdong, covering the coastal and offshore areas of western Guangdong. CTDs were deployed on site to obtain hydrological data such as temperature and salinity, and seawater samples were collected through water samplers to analyze the hydrogen and oxygen isotopes of water. The upwelling influence area was identified based on the water distribution characteristics of parameters such as temperature and salinity;

[0075] Step 2: Identify the surface water in the upwelling affected area, the surface water in the non-upwelling affected area, and the deep water in the upwelling affected area based on the horizontal distribution map, cross-sectional distribution map, temperature-salinity relationship map, etc. of temperature, salinity, and hydrogen and oxygen isotopes of water;

[0076] Step 3: The surface water in the upwelling zone is formed by mixing the surface water in the non-upwelling zone and the deep water in the upwelling zone. Based on the average oxygen isotope values ​​of different water bodies (surface water in the non-upwelling zone: δ 18 O=0.2‰; Deep water in the upwelling area: δ 18 O=0.7‰; Surface water in the upwelling area: δ 18 O=0.7‰), and establish a mass balance model based on oxygen isotopes;

[0077] Step 4: Use the isotope mass balance model to calculate the proportion of different water sources in the upwelling area. It is calculated that the surface water in the upwelling area in western Guangdong in spring is contributed by 40% of deep water and 60% of surface water in non-upwelling areas.

[0078] Step 5: According to the nutrient concentration (NO3 - NH4 + PO4 3- and SiO3 2- The concentrations of NO3 - NH4 + PO4 3- and SiO3 2-The concentrations of NO3 in the upwelling zone were 0.36 μmol / L, 0.56 μmol / L, 0.22 μmol / L and 4.05 μmol / L respectively) and their contribution ratios to the surface water in the upwelling zone were used to estimate the theoretical concentrations of various nutrients in the upwelling zone (NO3 - NH4 + PO4 3- and SiO3 2- The concentrations were 0.36μmol / L, 0.56μmol / L, 0.22μmol / L and 4.05μmol / L);

[0079] Step 6: Measured NO3 in surface water in the upwelling affected area - NH4 + PO4 3- and SiO3 2- The average concentrations of NO3 were 0.08 μmol / L, 0.41 μmol / L, 0.21 μmol / L, and 2.81 μmol / L, respectively. By comparing the theoretical values ​​with the measured values, it was found that NO3 - NH4 + PO4 3- and SiO3 2- The measured values ​​are 69%, 29%, -1% and 43% lower than the theoretical values, respectively, indicating that the organisms in the upwelling zone have significant absorption of nitrogen and silicon in spring.

[0080] Embodiment 2

[0081] Summer coastal upwelling in western Guangdong:

[0082] Step 1: In August 2018 (summer), five sections with a total of 33 stations were arranged in the range of 20.0-21.5°N and 110.0 and 112.0°E in the coastal waters of western Guangdong, covering the coastal and offshore areas of western Guangdong. CTDs were deployed on site to obtain hydrological data such as temperature and salinity, and seawater samples were collected through water samplers to analyze the hydrogen and oxygen isotopes of water. The upwelling influence area was identified based on the water distribution characteristics of parameters such as temperature and salinity;

[0083] Step 2: Identify the surface water in the upwelling affected area, the surface water in the non-upwelling affected area, and the deep water in the upwelling affected area based on the horizontal distribution map, cross-sectional distribution map, temperature-salinity relationship map, etc. of temperature, salinity, and hydrogen and oxygen isotopes of water;

[0084] Step 3: The surface water in the upwelling zone is formed by mixing the surface water in the non-upwelling zone and the deep water in the upwelling zone. Based on the average oxygen isotope values ​​of different water bodies (surface water in the non-upwelling zone: δ 18 O=-1.9‰; Deep water in the upwelling area: δ 18 O=-0.3‰; Surface water in the upwelling area: δ18 O=-0.8‰), and establish a mass balance model based on oxygen isotopes;

[0085] Step 4: Use the isotope mass balance model to calculate the proportion of different water sources in the upwelling area. It is calculated that in summer, the surface water in the upwelling area in western Guangdong is contributed by 69% of deep water and 31% of surface water in non-upwelling areas.

[0086] Step 5: According to the surface water (NO3 - NH4 + PO4 3- and SiO3 2- The concentrations of NO3 in the deep water were 12.15 μmol / L, 2.35 μmol / L, 0.70 μmol / L and 13.57 μmol / L respectively, and the nutrient concentrations in the deep water in the upwelling area (NO3 - NH4 + PO4 3- and SiO3 2- The concentrations of NO3 in the surface water of the upwelling zone were 1.91 μmol / L, 0.55 μmol / L, 0.26 μmol / L and 3.62 μmol / L respectively) and their contribution ratios to the upwelling zone were used to estimate the theoretical concentrations of various nutrients in the surface water of the upwelling zone (NO3 - NH4 + PO4 3- and SiO3 2- The concentrations were 6.01μmol / L, 1.27μmol / L, 0.44μmol / L and 7.60μmol / L);

[0087] Step 6: Measured NO3 in surface water in the upwelling affected area - NH4 + PO4 3- and SiO3 2- The average concentrations of NO3 were 0.32μmol / L, 0.53μmol / L, 0.14μmol / L, and 1.37μmol / L, respectively. Comparing the theoretical values ​​with the measured values, it was found that NO3 - NH4 + PO4 3- and SiO3 2- The measured values ​​are 95%, 58%, 68% and 82% lower than the theoretical values, respectively, indicating that the organisms in the upwelling zone in summer have a significant absorption of various nutrients and a significant impact on biological processes.

[0088] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for quantifying upwelling intensity and its biogeochemical processes based on hydrogen and oxygen isotopes, characterized in that: include: Obtain hydrological information and hydrogen and oxygen isotope values ​​of the target sea area and establish a hydrogen and oxygen isotope mass balance model; Based on the hydrogen and oxygen isotope mass balance model, the proportion of water bodies from different sources in the upwelling influence area of ​​the target sea area is calculated to obtain the contribution of deep water to the upwelling influence area; Estimate the theoretical nutrient concentration in the upwelling affected area based on the nutrient concentration of the original surface water and the deep water in the upwelling source area and the contribution of the deep water to the upwelling affected area; The measured nutrient concentration in the upwelling influence zone is compared with the theoretical nutrient concentration to obtain the contribution of the biological process in the target sea area.

2. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 1, characterized in that: Establishing the hydrogen and oxygen isotope mass balance model includes: Obtaining the hydrological information and hydrogen and oxygen isotope values; The upwelling influence area is identified and differentiated through the relationship between temperature, salinity and water hydrogen and oxygen isotopes, and the differentiation results are obtained; Identifying the differentiation results to form different water masses of the upwelling mixed water body, and determining the hydrogen and oxygen isotope values ​​of different end-member waters based on the hydrological information and the hydrogen and oxygen isotope values; The isotope mass balance model is established based on the different water masses of the upwelling mixed water body and the hydrogen and oxygen isotope values ​​of the upwelling influence zone.

3. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 2, characterized in that: The hydrological information of the target sea area includes: The hydrological information is obtained by using CTD detection, wherein the survey time is the season when the upwelling influence is obvious.

4. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 3, characterized in that: Obtaining the hydrogen and oxygen isotope values ​​of the target sea area includes: In the target sea area, a Niskin water sampler is used to obtain seawater from different layers. When obtaining seawater, the seawater is exposed to air for the same length of time, filled and sealed in glass bottles, and then the hydrogen and oxygen isotope values ​​of the seawater are measured using a gas stable isotope ratio mass spectrometer within a fixed time period.

5. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 2, characterized in that: Identification and differentiation of upwelling affected areas through the relationship between temperature, salinity and water hydrogen and oxygen isotopes include: Determine the surface water in the upwelling affected area, the surface water in the non-upwelling affected area, and the deep water in the upwelling affected area based on the plane distribution map and cross-sectional distribution map of the temperature, salinity, and water hydrogen and oxygen isotopes in the target sea area; The surface water in the upwelling influence zone is formed by mixing the surface water in the non-upwelling influence zone and the deep water in the upwelling influence zone.

6. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 5, characterized in that: The isotope mass balance model is: X h =f b ×X b +f s ×X s ; f b +f s =1; Where, X h is the average value of hydrogen isotopes or oxygen isotopes in the surface water in the upwelling zone; X b is the average value of hydrogen isotope or oxygen isotope of surface water in the non-upwelling area; X s is the average value of hydrogen isotopes or oxygen isotopes in the deep water in the upwelling zone; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

7. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 1, characterized in that: According to the law of nutrient mass balance in the physical mixing process, the theoretical nutrient concentration in the upwelling influence area is quantitatively estimated as follows: Y h =f b ×Y b +f s ×Y s ; Where Y h is the theoretical estimated value of the nutrient concentration in the surface water of the upwelling area; Y b Y is the average nutrient concentration of the surface layer in the non-upwelling area; s is the average nutrient concentration of deep water in the upwelling area; f b is the proportion of surface water in the non-upwelling affected area; f s is the proportion of deep water in the upwelling affected area.

8. The method for quantifying upwelling intensity and its biogeochemical process based on hydrogen and oxygen isotopes according to claim 7, characterized in that: Comparison of the measured nutrient concentration in the upwelling affected area with the theoretical estimate of the nutrient concentration in the surface water of the upwelling affected area includes: The average value of the measured nutrient concentration in the upwelling influence area is recorded as Z h ; If (Y h -Z h ) / Y h ≤ the preset threshold, it is considered that the physical process in the upwelling influence area is dominant and the influence of biological processes can be ignored; If (Y h -Z h ) / Y h ≥ the preset threshold, it is considered that the upwelling influence area has an impact on the biological process.

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