Underway shipborne observation system and method

Abstract

The invention discloses an underway shipborne observation system and method, the system comprises an ultrasonic anemograph, a closed-circuit measurement system, an auxiliary meteorological observation system, a motion monitoring system and a data processing and storage unit, and the closed-circuit measurement system comprises a drying pipe, a first vacuum pump, a gas analyzer and a second vacuum pump which are communicated in sequence. The meteorological mast of the bow of the current scientific examination ship is fully utilized, observation cost is reduced, observation equipment and the installation position of the observation equipment are scientifically selected, data sampling sufficiency and accuracy are guaranteed, observation errors caused by the fact that vertical airflow is affected by the ship body are avoided through the design of the installation height, and observation accuracy is improved. A closed-loop measurement system is combined on observation tests, closed-loop double-pump sampling is adopted, vertical wind speed information is reserved to the maximum extent, the influence of ocean droplets is reduced while the water vapor absorption effect is avoided through closed-loop type drying sampling, the ocean greenhouse gas exchange rate is effectively observed, and the influence of ship body shaking on a ship-borne observation system is avoided.

Description

Technical Field

[0001] This invention relates to the field of marine observation technology, and in particular to a mobile shipborne observation system and method. Background Technology

[0002] The exchange of matter and energy between the ocean and the atmosphere has always been a key focus of international ocean-atmosphere research. Due to the complexity of ocean currents and the differences in seawater properties, the limited number of nearshore station-based turbulence observations lack spatial continuity, making it difficult to deeply reveal the differences in the distribution of air-sea fluxes. Therefore, there is an urgent need to develop continuous observation techniques for air-sea turbulence exchange. Shipborne observations offer a certain speed, enabling the rapid formation of spatially linear sampling sequences, avoiding the influence of temporal trends and unsteady-state effects, and thus have broad application prospects.

[0003] Chinese patent application number CN201820556014.5 discloses a shipborne mobile air-sea flux observation system. It provides a shipborne mobile air-sea flux observation system consisting of an atmospheric detection subsystem, an underwater measurement subsystem, a multi-sensor data integration system, gas pipelines, and data transmission cables. This system is a marine survey and measurement technology equipment that integrates atmospheric multi-element observation system, underwater multi-element observation system, and real-time data display and online data processing functions. It can synchronously and stably conduct synchronous three-dimensional comprehensive observation of multiple elements affecting air-sea interaction in the marine environment.

[0004] Chinese Patent Application No. CN201910620131.2 discloses a shipborne automatic air-sea flux observation system. It fully considers the requirements of comprehensive factors in air-sea flux observation. Through simple installation and setup and the cooperation of several sensors, it can observe multiple meteorological elements such as net solar radiation, three-dimensional wind direction and speed, air temperature, relative humidity, and acoustics. The system can provide researchers with accurate scientific data. It is also equipped with a cantilever retraction mechanism, which can control the automatic retraction of the cantilever under the action of an external control switch. After the cantilever is extended, the corresponding observation equipment is movably connected to the cantilever by a detachable movable sleeve, which facilitates the installation and disassembly of the observation equipment.

[0005] However, the above technologies have significant observational errors. These errors mainly come from the influence of high ocean humidity, ocean spray, and airflow distortion caused by installation strategies. In addition, the observation technologies focus more on ocean meteorological factors, turbulent heat flux, momentum flux, etc., and pay little attention to the intensity of ocean absorption of greenhouse gases. Summary of the Invention

[0006] This invention provides a mobile shipborne observation system and method to address the technical problems of large observation errors in existing observation technologies and the difficulty in effectively observing the intensity of ocean absorption of greenhouse gases.

[0007] The present invention provides a mobile shipborne observation system, comprising an ultrasonic anemometer, a closed-circuit measurement system, an auxiliary meteorological observation system, a motion monitoring system, and a data processing and storage unit;

[0008] An air inlet is provided near the support arm of the ultrasonic anemometer, and the air inlet is connected to the closed-circuit measurement system through a polytetrafluoroethylene tube.

[0009] The closed-circuit measurement system is installed in the cabin on the foredeck; the closed-circuit measurement system includes a drying tube, a first vacuum pump, a gas analyzer, and a second vacuum pump connected in sequence; the gas analyzer is used to measure the concentration of carbon dioxide and methane in the sea surface air;

[0010] The auxiliary meteorological observation system is located at the top of the meteorological mast at the bow;

[0011] A stainless steel pipe extending along the sea surface is installed at a predetermined first distance between the meteorological mast and the foredeck; the predetermined first distance is determined by the height of the foredeck above the sea surface and the vertical wind speed at the sea surface.

[0012] The ultrasonic anemometer is installed at one end of the stainless steel tube and is used to observe the three-dimensional wind speed at the sea surface.

[0013] The motion monitoring system is installed at the junction of the stainless steel pipe and the meteorological mast, and is used to observe the motion data of the ultrasonic anemometer as it moves with the ship.

[0014] The data processing and storage unit is communicatively connected to the ultrasonic anemometer, the gas analyzer, the auxiliary meteorological observation system, and the motion monitoring system, respectively.

[0015] Furthermore, a first filter for filtering liquid water is provided at the air inlet, and a heating device is provided inside the first filter.

[0016] Furthermore, the auxiliary meteorological observation system includes air temperature and humidity sensors, solar radiation sensors, sea surface temperature sensors, and wind speed and direction sensors;

[0017] A stainless steel pipe is installed at the top of the meteorological mast, and the air temperature and humidity sensor, the solar radiation sensor, the sea surface temperature sensor, and the wind speed and direction sensor are sequentially installed on the stainless steel pipe at the top of the meteorological mast.

[0018] The sea surface temperature sensor is installed at an angle towards the sea surface at the bow of the ship.

[0019] Furthermore, a three-way valve and a second filter are sequentially connected between the first vacuum pump and the gas analyzer;

[0020] The second filter is used to filter solid particles and liquid water.

[0021] Furthermore, it also includes: calibration devices;

[0022] The calibration device is connected to the gas analyzer and is used to calibrate the gas analyzer.

[0023] Furthermore, the gas analyzer is specifically a Picaro series model, and the sampling frequency of the gas analyzer is 10Hz;

[0024] The ultrasonic anemometer is specifically a Gill WindMaster Pro series model;

[0025] The drying tube is specifically a Nafion drying tube.

[0026] Furthermore, the pumping speed of the first vacuum pump is 20 L / min, and the pumping speed of the second vacuum pump is 5 L / min.

[0027] Furthermore, the first filter is made of a hydrophobic material, specifically a Teflon membrane filter.

[0028] Furthermore, the second filter is specifically a disc filter.

[0029] The present invention also provides a method for underway shipborne observation, the method comprising:

[0030] The three-dimensional wind speed at the sea surface is observed using an ultrasonic anemometer; the motion data of the ultrasonic anemometer as it moves with the ship is measured using a motion monitoring system; and the concentrations of carbon dioxide and methane in the sea surface air are measured using a gas analyzer.

[0031] Based on the motion data, the three-dimensional wind speed is corrected to generate the true three-dimensional wind speed of the sea surface;

[0032] The shipboard greenhouse gas absorption rate is generated based on the observed three-dimensional wind speed, the carbon dioxide concentration, and the methane concentration.

[0033] As can be seen from the above technical solutions, the present invention has the following advantages:

[0034] This invention provides a mobile shipborne observation system and method. The mobile shipborne observation system includes an ultrasonic anemometer, a closed-circuit measurement system, an auxiliary meteorological observation system, a motion monitoring system, and a data processing and storage unit. An air inlet is located near the support arm of the ultrasonic anemometer, and the air inlet is connected to the closed-circuit measurement system via a polytetrafluoroethylene (PTFE) tube. The closed-circuit measurement system is located in the cabin on the foredeck. The closed-circuit measurement system includes a drying tube, a first vacuum pump, a gas analyzer, and a second vacuum pump connected in sequence. The gas analyzer is used to measure the concentrations of carbon dioxide and methane in the sea surface air. The auxiliary meteorological observation system... The measurement system is located at the top of the meteorological mast at the bow; a stainless steel pipe extending towards the sea surface is installed at a predetermined first distance between the meteorological mast and the foredeck; the predetermined first distance is determined by the height of the foredeck above the sea surface and the vertical wind speed at the sea surface; an ultrasonic anemometer is installed at one end of the stainless steel pipe to observe the three-dimensional wind speed at the sea surface; a motion monitoring system is installed at the junction of the stainless steel pipe and the meteorological mast to observe the motion data of the ultrasonic anemometer as it moves with the ship; the data processing and storage unit is communicatively connected to the ultrasonic anemometer, the gas analyzer, the auxiliary meteorological observation system, and the motion monitoring system, respectively.

[0035] This invention makes full use of the meteorological mast built into the bow of current scientific research vessels to reduce observation costs. It scientifically selects observation equipment and determines the installation location of the equipment, ensuring the sufficiency and accuracy of data sampling. In the observation experiment, it combines a closed-circuit measurement system to reduce observation errors, effectively observe the rate of marine greenhouse gas exchange, and avoid the impact of ship rolling on the shipborne observation system. Thus, it solves the technical problems of large observation errors and difficulty in effectively observing the intensity of marine absorption of greenhouse gases in existing observation technologies. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a mobile shipborne observation system provided in an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the communication connection of a mobile shipborne observation system provided in an embodiment of the present invention.

[0039] The attached figures are labeled as follows: 1. Ultrasonic anemometer; 2. Auxiliary meteorological observation system; 21. Air temperature and humidity sensor; 22. Solar radiation sensor; 23. Sea surface temperature sensor; 24. Wind speed and direction sensor; 3. Motion monitoring system; 4. Closed-circuit measurement system; 41. Air inlet; 42. First filter; 43. Polytetrafluoroethylene tube; 44. Drying tube; 45. First vacuum pump; 46. Three-way valve; 47. Second filter; 48. Gas analyzer; 49. Second vacuum pump; 5. Meteorological mast; 6. Stainless steel tube; 7. Calibration device; 8. Data processing and storage unit; 9. Data display unit. Detailed Implementation

[0040] This invention provides a mobile shipborne observation system and method to address the technical problems of large observation errors in existing observation technologies and the difficulty in effectively observing the intensity of ocean absorption of greenhouse gases.

[0041] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] Ship-based: Observational experiments conducted using ships as observation platforms.

[0043] Greenhouse gases: referring to carbon dioxide and methane.

[0044] Ship motion: the ship's speed, and the angular sway and angular velocity changes caused by turning, rolling, and pitching.

[0045] Motion monitoring: Observe the state records of the ultrasonic anemometer as it moves with the ship, including horizontal speed, pitch angle, and roll angle.

[0046] Water vapor absorption effect: The absorption of light wave energy by water vapor in a closed-circuit analyzer.

[0047] Please see Figure 1 An embodiment of a mobile shipborne observation system provided in this application includes an ultrasonic anemometer 1, a closed-circuit measurement system 4, an auxiliary meteorological observation system 2, a motion monitoring system 3, and a data processing and storage unit 8;

[0048] An air inlet 41 is provided near the support arm of the ultrasonic anemometer 1. The air inlet 41 is connected to the closed-circuit measurement system 4 through a polytetrafluoroethylene tube 43. The closed-circuit measurement system 4 is located in the cabin on the foredeck. The closed-circuit measurement system 4 includes a drying tube 44, a first vacuum pump 45, a gas analyzer 48, and a second vacuum pump 49 connected in sequence. The gas analyzer 48 is used to measure the concentration of carbon dioxide and methane in the sea surface air.

[0049] The auxiliary meteorological observation system 2 is set at the top of the meteorological mast 5 at the bow; a stainless steel pipe 6 extending in the direction of the sea surface is set at a preset first distance between the meteorological mast 5 and the foredeck; an ultrasonic anemometer 1 is installed at one end of the stainless steel pipe 6 to observe the three-dimensional wind speed at the sea surface; a motion monitoring system 3 is installed at the junction of the stainless steel pipe 6 and the meteorological mast 5 to observe the motion data of the ultrasonic anemometer 1 as it moves with the ship.

[0050] The data processing and storage unit 8 is communicatively connected to the ultrasonic anemometer 1, the gas analyzer 48, the auxiliary meteorological observation system 2, and the motion monitoring system 3, respectively.

[0051] Understandably, placing the closed-circuit measurement system 4 in the cabin on the foredeck can shorten the sampling pipeline and improve the safety and stability of the equipment. The closed-circuit measurement system 4 can accurately and continuously collect, process and analyze specific gas components in the sea surface air.

[0052] The observation process of the closed-circuit measurement system 4 is as follows: First, the first vacuum pump 45 is started to establish a negative pressure state in the closed-circuit measurement system 4, so that the sea surface air near the ultrasonic anemometer 1 continuously and stably enters the gas analyzer 48 through the drying tube 44, which fully ensures the turbulent state of the extracted sea surface air. As the core part of the closed-circuit measurement system 4, the gas analyzer 48 can analyze the pre-treated sea surface air to measure the concentration of specific gases (such as greenhouse gases, carbon dioxide, and methane). At the same time, the second vacuum pump 49 is also started to ensure that the flow rate of the sea surface air entering the gas analyzer 48 is moderate, which is conducive to the gas analyzer 48 to perform accurate gas analysis. It can also assist the cyclic operation of the closed-circuit measurement system 4 to help exhaust the exhaust gas after analysis by the gas analyzer 48, so that the closed-circuit measurement system 4 can enter the next round of sampling.

[0053] Understandably, the inner diameter of the PTFE tube 43 is preferably 6 mm, and the length is preferably 20 m. The PTFE tube 43 has good corrosion resistance, protecting the sea surface air from chemical corrosion, while maintaining temperature stability, airtightness, and low permeability during transmission. The drying tube 44 is used to remove moisture from the sea surface air to prevent moisture from affecting the subsequent gas analyzer 48 (such as corrosion, interference with test signals, etc.), while avoiding the influence of water vapor on the observation of greenhouse gas concentrations. The first vacuum pump 45 and the second vacuum pump 49 adopt different pumping rates. The first vacuum pump 45 is responsible for primary sampling, and the second vacuum pump 49 is responsible for fine sampling.

[0054] The gas analyzer 48 used in this invention is a closed-circuit device, whereas existing methods typically use open-circuit devices for observation. However, open-circuit devices are susceptible to the effects of water vapor absorption and primarily observe the mass concentration of substances, making them easily affected by temperature. Compared to open-circuit devices, closed-circuit observation uses mixing ratios or mole fractions, avoiding density changes caused by temperature variations. Furthermore, the gas analyzer 48 is fixedly installed below the bow deck, ensuring equipment safety and avoiding the influence of direct sunlight.

[0055] The observation of shipborne air-sea flux requires a clear observation location to avoid obstruction by the ship's structure. In this invention, to ensure accurate measurement of sea surface wind speed, the installation height of the ultrasonic anemometer 1 and the motion monitoring system 3 needs to take into account the vertical velocity of the sea surface wind and the height of the foredeck, so as to effectively reduce the obstruction effect of the vertical structure of the bow on the wind speed, thereby avoiding a significant upward shift in the wind speed data caused by strong upward movement of the sea surface wind.

[0056] Specifically, assuming the foredeck is considered the ground, the horizontal wind speed at the foredeck would drop to 0. When the wind blows towards the bow, it is forced to rise due to the influence of the ship's deck, causing a change in the height at which the horizontal wind speed drops to 0, i.e., a zero-plane displacement. In a dense forest on land, this height is approximately 0.6 times the height of the vegetation. If we consider the height H of the foredeck from the sea surface as vegetation, we can imagine that the height at which the horizontal wind speed drops to 0 has shifted upwards by 0.6H. Furthermore, assuming the foredeck is perpendicular to the sea surface, the vertical wind speed will produce an upward acceleration. Assuming the wind speed at the sea surface is 0, the speed at the height H of the deck can be approximated as its maximum value. Assuming the acceleration remains constant but in the opposite direction, it will drop back to 0 after passing a height of H. Therefore, H + 0.6H = 1.6 times H is sufficient to offset the effect of the ship's deck on the vertical wind speed. For ease of operation and maintenance safety, as well as cost requirements, the height is conservatively set at 1.5H.

[0057] Therefore, in this observation system, the installation height of the stainless steel pipe 6, which houses the ultrasonic anemometer 1 and the motion monitoring system 3, can be set to 1.5 times the height of the foredeck above the sea surface. This effectively avoids strong upward movement of sea surface wind speed due to obstruction by the ship's hull. Simultaneously, the preferred length of the stainless steel pipe 6 extending along the sea surface is 1.5m, facilitating the reception of sea surface information by the ultrasonic anemometer 1 and the closed-circuit measurement system 4, while also avoiding interference from the ship's hull or deck. Furthermore, during installation, the air inlet 41 needs to be close to the support arm of the ultrasonic anemometer 1 to ensure that the air inlet 41 is as close as possible to the center of gravity of the ultrasonic anemometer 1, thereby greatly reducing the spatial separation effect caused by instrument separation.

[0058] In terms of data observation, the auxiliary meteorological observation system 2 is used to observe marine meteorological observation data and serve marine meteorological observation; the ultrasonic anemometer 1 is used to observe the three-dimensional wind speed at the sea surface; the motion monitoring system 3 is used to observe the motion data of the ultrasonic anemometer 1 as the ship moves, specifically including the horizontal movement speed (V), roll angle (φ), roll speed (v1), pitch angle (θ), pitch speed (v2), and yaw angle (ψ) of the ship, etc., and based on these motion data, the influence of the closed-circuit measurement system 4 on the ship's motion can be monitored; the gas analyzer 48 is used to measure the concentration of greenhouse gases in the sea surface air.

[0059] Please see Figure 2 This shipborne observation system also includes a data display unit 9. The data processing and storage unit 8 is communicatively connected to the data display unit 9, which displays shipborne observation data and results. The data processing and storage unit 8 collects and processes observation data from the auxiliary meteorological observation system 2, the ultrasonic anemometer 1, the motion monitoring system 3, and the gas analyzer 48, outputting various observation results, such as the true three-dimensional wind speed at the sea surface, the shipborne greenhouse gas absorption rate, and the flux contribution source region. The display of observation data and results contributes to research in areas such as marine meteorology and climate, ocean dynamics, turbulent exchange, and maritime traffic.

[0060] In particular, during continuous observation, after the data processing and storage unit 8 collects the shipborne observation data, it will perform data calculation and processing on the shipborne observation data within a preset first interval period and send it to the data display unit 9 for display. During data processing, the data processing and storage unit 8 will further divide the preset first interval period and the shipborne observation data into multiple sample datasets, and propose abnormal sample datasets during the calculation process to improve the reliability of the data processing results.

[0061] For example, assuming the preset interval period set by the data processing and storage unit 8 is 30 minutes, and the data processing and storage unit 8 collects 18,000 observation data within 30 minutes, then the 18,000 observation data within 30 minutes can be divided into 6 sample datasets, each sample dataset corresponding to 3,000 observation data. Based on the observation results calculated for each sample dataset, the observation data after passing the turbulence stability test and variance similarity test are averaged. In this way, the obtained observation results satisfy the observation theory conditions related to eddy currents to the greatest extent, making the results more reliable; and increasing the final effective observation data sample size. If there are outliers in the flux calculated for the entire sample over 30 minutes, which would cause the observation results to be abnormal, then the average observation value of the 30 minutes is removed as an outlier. However, by dividing the data samples for calculation, the outlier is only removed in small intervals, while the observation results over 30 minutes are still usable.

[0062] The flux contribution source region refers to the sea area significantly affected by specific fluxes (such as energy and mass exchange) recorded by shipborne sensors. Currently, the two most widely used calculation models for flux contribution source regions are the KM model (proposed by Kormann and Meixner et al.) and the KL model (proposed by Kljun et al.). Existing flux source region calculations generally use one of these two models. In this shipborne observation system, the appropriate model is selected based on actual conditions: when the friction velocity is greater than a preset velocity threshold (e.g., 0.2) and -200 < atmospheric stability z / L < 1, the KL model is used; otherwise, the KM model is used. Here, the friction velocity is determined by the observed three-dimensional wind speed, and z in atmospheric stability z / L refers to the observation altitude, while L is the Obukhov length, determined by the air temperature observed by the auxiliary meteorological observation system 2 and the three-dimensional wind speed observed by the ultrasonic anemometer 1.

[0063] This invention employs a lightweight and sensitive attitude monitoring system (auxiliary meteorological observation system 2 and motion monitoring system 3) to directly monitor the state of the shipborne observation system affected by the ship. It addresses the error caused by converting ship center of gravity position monitoring data to the shipborne observation system. Assuming the observation system's center of gravity is the origin (0, 0, 0), the distance between the observation system and the attitude monitoring system (usually located at the ship's center of gravity) is D = (d1, d2, d3), where d1 is the horizontal distance of the ship's center of gravity along the observation system's center of gravity, d2 is the eastward deviation of the ship's center of gravity along the observation system's center of gravity, and d3 is the vertical distance of the ship's center of gravity along the observation system's center of gravity. The attitude monitoring system's velocity is V, and its angle is R. Converting V and R to the observation system's position yields Vnew = V × D and Rnew = R × D. This calculation easily amplifies high-frequency signal noise, leading to an overestimation of the velocity at the observation location. By directly mounting a lightweight attitude instrument near the observation system, this process is largely negligible, ensuring the accuracy of the observation.

[0064] In this invention, based on the limited space of the ship, the meteorological mast 5 built into the bow of the current scientific research vessel is fully utilized, and the observation equipment and its installation position are scientifically selected to ensure the sufficiency of data sampling to the greatest extent. The installation height of the ultrasonic anemometer 1 and the motion monitoring system 3 is designed to avoid the observation error caused by the influence of the ship's hull on the vertical airflow, thus reducing the observation cost. Existing air-sea flux observation systems that usually use the ship's own attitude instrument monitoring data to correct for errors may have errors. This invention selects a high-precision and lightweight attitude monitoring device (auxiliary meteorological observation system 2 and motion monitoring system 3) and closely links it with the closed-circuit measurement system 4. The installation position is adjusted to better capture the influence of the ship's sway on the shipborne observation system. At the same time, the closed-circuit measurement system 4 adopts closed-circuit dual-pump sampling in the experimental design to retain vertical wind speed information to the greatest extent. Moreover, the closed-circuit dry sampling avoids the water vapor absorption effect and also reduces the influence of ocean spray. Combined with the ultrasonic anemometer 1 and the gas analyzer 48, the direct observation of the rate of greenhouse gas absorption in the ocean is effectively realized.

[0065] This shipborne observation system makes full use of the scientific (meteorological) mast on the bow of current research vessels, scientifically selects observation equipment and sampling schemes, and provides a simple, safe and efficient shipborne observation solution. The installation of observation equipment and the sampling method of closed-circuit measurement system 4 can ensure the sufficiency of data sampling to the greatest extent, reduce observation errors, effectively observe the rate of marine greenhouse gas exchange and the impact of ship rolling on the shipborne observation system, start from the atmosphere, capture high-frequency changes in greenhouse gas concentration, directly give the rate of marine absorption of greenhouse gases, and develop marine greenhouse gas observation technology.

[0066] In one specific embodiment, a first filter 42 for filtering liquid water is provided at the air inlet 41, and a heating device is provided inside the first filter 42.

[0067] Understandably, the first filter 42 serves to block liquid water and prevent excessive liquid water from entering the polytetrafluoroethylene tube 43; the heating device installed in the first filter 42 can prevent water vapor from freezing in cold environments, which could cause blockage at the pipe inlet and affect the operating accuracy of the closed-loop measurement system 4.

[0068] In one specific embodiment, the auxiliary meteorological observation system 2 includes an air temperature and humidity sensor 21, a solar radiation sensor 22, a sea surface temperature sensor 23, and a wind speed and direction sensor 24.

[0069] A stainless steel pipe 6 is installed at the top of the meteorological mast 5, and an air temperature and humidity sensor 21, a solar radiation sensor 22, a sea surface temperature sensor 23, and a wind speed and direction sensor 24 are installed sequentially on the stainless steel pipe 6 at the top of the meteorological mast 5.

[0070] The sea surface temperature sensor 23 is installed at an angle towards the sea surface at the bow of the ship.

[0071] In this system, the auxiliary meteorological observation system 2 is installed parallel to the deck at the top of the meteorological mast 5 via a 1-meter-long stainless steel pipe 6. The auxiliary meteorological observation system 2 provides routine marine meteorological observation data, such as air temperature and humidity, net solar radiation, wind speed and direction, and sea surface temperature. This marine meteorological observation data characterizes sea surface meteorological conditions, serves marine meteorological observation, and can be used to calculate the source areas of marine greenhouse gases. For example, radiation observation combined with the observation system's heat can directly obtain information on the ocean's heat absorption, while the difference between sea surface temperature and air temperature can be used to determine the direction of turbulent transport.

[0072] In one specific embodiment, a three-way valve 46 and a second filter 47 are sequentially connected between the first vacuum pump 45 and the gas analyzer 48; the second filter 47 is used to filter solid particles and liquid water.

[0073] It should be noted that in practical applications, the use of the three-way valve 46 needs to be controlled according to different application scenarios, selectively guiding sea surface air to the gas analyzer 48 or performing other operations (such as venting, regeneration, etc.). This flexibility allows the closed-loop measurement system 4 to switch between different operating modes. For example, during routine sea surface air analysis, the three-way valve 46 guides the gas to the gas analyzer 48, and then vents the sea surface air that has been analyzed and processed by the gas analyzer 48; or, during maintenance or calibration of the closed-loop measurement system 4, the sea surface air can be vented or transmitted along the delivery loop to the drying tube 44 for regeneration.

[0074] In one specific embodiment, it further includes: a calibration device 7; the calibration device 7 is connected to the gas analyzer 48, and the calibration device 7 is used to calibrate the gas analyzer 48.

[0075] Understandably, the gas analyzer 48 can be calibrated every 7 days using calibration device 7 to avoid potential observation drift and reduce the drift in the greenhouse gas concentration observed by the gas analyzer 48. The calibration process is as follows: Standard gas is used, and the flow rate of the standard gas from the cylinder is controlled by a pressure reducing valve, allowing the standard gas to enter the gas analyzer 48 for observation. Calibration consists of two steps: the first step is zeroing, which calibrates the observation zero point of the gas analyzer 48, using nitrogen gas with a purity of 99.99%; the second step is full-scale calibration, which calibrates the maximum concentration observed by the gas analyzer 48, using carbon dioxide standard gas with a concentration not less than 99.5%.

[0076] In one specific embodiment, the gas analyzer 48 is a Picarro series model and the sampling frequency of the gas analyzer 48 is 10Hz; the ultrasonic anemometer 1 is a Gill WindMaster Pro series model; and the drying tube 44 is a Nafion drying tube 44 (1 / 8” compression fitting).

[0077] It should be noted that since methane, a greenhouse gas, is relatively scarce in the ocean, observation requires extremely high precision. This system uses the Picarro series closed-circuit analyzer, which can simultaneously observe carbon dioxide and methane. It features unique automatic water vapor correction, shock and vibration resistance, and ultra-high sensitivity. It is also insensitive to changes in ambient temperature, meeting the requirements for monitoring changes in methane concentration. It is highly accurate and free from fact drift. The gas analyzer 48 uses 10Hz high-frequency sampling, which can better capture the fine structure of turbulence, thereby obtaining the subtle structure of greenhouse gas movement.

[0078] The ship's hull is extremely vulnerable to the impact of waves during navigation, and the ultrasonic anemometer 1 is easily damaged by wave impact. Therefore, this system selects the Gill WindMaster Pro series ultrasonic anemometer 1. This model of anemometer has a wind speed resolution of 0.01m / s and a range of 0-65m / s. It is suitable for marine observation, and is cost-effective, easy to replace, and can maintain the continuity of observation data to the greatest extent.

[0079] In one specific embodiment, the first vacuum pump 45 uses high flow rate sampling, while the second vacuum pump 49 uses low flow rate sampling; specifically, the pumping rate of the first vacuum pump 45 is 20 L / min, and the pumping rate of the second vacuum pump 49 is 5 L / min.

[0080] In this invention, the dual pumps employ different sampling flow rates. The dual-pump design is an improvement upon the single-pump design. When collecting gas using a single pump, the closed-loop analyzer has inherent limitations, restricting the pumping rate to a minimum, typically set at 10 L / min. Due to the long gas pipeline, adsorption friction on the inner wall causes the gas to transition from turbulent to laminar flow, compromising turbulent properties and resulting in minimal changes in concentration. The dual-pump design significantly alters this situation.

[0081] Before entering the gas analyzer 48, the gas is sampled at a high flow rate. Specifically, the first vacuum pump 45 uses a high flow rate for initial sampling, quickly and efficiently introducing sea surface air into the system. This ensures timely response to wind field changes, capturing instantaneous wind speed and direction information, significantly reducing the time delay effect on air mass concentration and wind speed observations, and fully preserving the turbulent properties of the collected gas. Then, the second vacuum pump 49 extracts the sea surface air already in the pipeline into the analyzer for measurement, completing fine sampling. This involves extracting the pre-treated air at a lower rate, ensuring a moderate sample flow rate into the gas analyzer 48, facilitating accurate component analysis and fully preserving the characteristics of concentration changes, resulting in more precise results.

[0082] By using two vacuum pumps with different sampling flow rates, the requirements for real-time wind speed data are met, while also taking into account the stability requirements for gas composition detection.

[0083] In one specific embodiment, the first filter 42 is made of a hydrophobic material, specifically a Teflon membrane filter. The Teflon membrane filter can block liquid water and prevent excessive liquid water from entering the exhaust pipe of the polytetrafluoroethylene tube 43.

[0084] In one specific embodiment, the second filter 47 is a disc filter. The disc filter further prevents liquid water and solid particles from entering the gas analyzer 48 and causing optical path contamination.

[0085] This invention provides a method for underway shipborne observation, the method comprising:

[0086] Step 101: Observe the three-dimensional wind speed at the sea surface using an ultrasonic anemometer; measure the motion data of the ultrasonic anemometer as it moves with the ship using a motion monitoring system; and measure the carbon dioxide and methane concentrations in the sea surface air using a gas analyzer.

[0087] It should be noted that after starting the first and second vacuum pumps, data can be collected through an ultrasonic anemometer, motion monitoring system and gas analyzer. The motion data includes the horizontal movement speed (V), roll angle (φ), roll speed (v1), pitch angle (θ), pitch speed (v2) and yaw angle (ψ) of the ship.

[0088] Step 102: Correct the three-dimensional wind speed based on motion data to generate the true three-dimensional wind speed of the sea surface.

[0089] It should be noted that the true three-dimensional wind speed at the sea surface refers to the wind speed in the Earth's reference frame. ), can be regarded as a measure of wind speed ( ) and horizontal movement speed ( ) and:

[0090]

[0091]

[0092] in, The horizontal speed representing the ship's motion, and the roll speed ( ) and pitch speed ( This is related to the motion monitoring system and can be directly measured. This indicates the three-dimensional wind speed to be observed ( The wind speed, converted to Earth coordinates, is related to pitch (θ), roll (φ), and heading (ψ).

[0093] During a ship's navigation, the motion of the ship's onboard observation system relative to the Earth's coordinate system includes the ship's movement, up-and-down motion, and swaying, including pitching, rolling, and instantaneous bow deviation caused by navigation.

[0094] Correcting for the effects of hull roll and hull movement on the observed three-dimensional wind speed ( The impact of pulsation observations was analyzed using ship motion attitude data to determine the observed three-dimensional wind speed. Corrected to the Earth coordinate system, where the x-axis points due north, the y-axis points due east, and the z-axis points vertically upward.

[0095] Assuming a ship's coordinate system, with the x-axis pointing towards the bow, the y-axis pointing towards the port side, and the z-axis pointing vertically upwards, then... Represented as:

[0096] u m = [ − u − v w ]

[0097] Where u, v, and w are the three-dimensional wind speeds observed by the ultrasonic anemometer.

[0098] Measuring wind speed ( ) and observed three-dimensional wind speed ( The conversion process is as follows:

[0099]

[0100] Where T is the transformation matrix between the ship's coordinate system and the Earth's coordinate system, and Ω is the angular velocity vector of the ultrasonic anemometer, they can be expressed as follows:

[0101] T = [ cos ψ sin ψ 0 − sin ψ cos ψ 0 0 0 1 ] [ cos i 0 sin i 0 1 0 − sin i 0 cos i ] [ 1 0 0 0 cos f − sin f 0 sin f cos f ]

[0102] Oh = [ f cos ψ cos i + i sin ψ i cos ψ − f sin ψ cos i − ψ − f sin i ]

[0103] M represents the three-dimensional distance between the attitude sensor and the closed-circuit measurement system.

[0104] M = [ x y z ]

[0105] Step 103: Based on the observed three-dimensional wind speed, carbon dioxide concentration, and methane concentration, generate the shipborne greenhouse gas absorption level.

[0106] It is understandable that the ocean absorbs and stores carbon dioxide (CO2) and methane (CH4) from the atmosphere. 4） It is one of the main ways to mitigate global climate change. Current research on global ocean absorption of atmospheric greenhouse gases focuses on addressing the seasonality and heterogeneity of regional oceans, particularly marginal seas, primarily the alternation of carbon sinks and sources at different spatial and temporal scales. Spatial patterns of greenhouse gas absorption intensity observed in regional studies indicate that individual marginal seas exhibit extensive spatial variability, making it difficult to classify and quantify greenhouse gas absorption intensity. Furthermore, although the seasonal differences in ocean greenhouse gas absorption are gradually recognized, its temporal variability is rarely studied. Moreover, the interannual variation or long-term trend of ocean greenhouse gas absorption intensity remains controversial. Therefore, there is an urgent need to develop continuous observation techniques for ocean greenhouse gas absorption. Traditional methods for ocean greenhouse gas absorption rates mainly involve analyzing seawater samples. Analyzing the pressure difference between greenhouse gas concentrations in seawater and the atmosphere, and then estimating using the bulk method, can introduce significant errors under low wind speed conditions.

[0107] In this invention, an ultrasonic anemometer and a gas analyzer are combined to efficiently and accurately achieve direct observation of the rate of greenhouse gas absorption in the ocean, ensuring the accuracy of the observation. Specifically, the degree of greenhouse gas absorption on board is mainly obtained by calculating the covariance of the vertical wind speed in the three-dimensional wind speed parameters with the fluctuations in carbon dioxide and methane concentrations, as detailed below:

[0108] Carbon dioxide absorption intensity for:

[0109]

[0110] in, This indicates vertical wind speed fluctuations. This indicates fluctuations in carbon dioxide concentration;

[0111] methane absorption strength for:

[0112]

[0113] in, This indicates vertical wind speed fluctuations. This indicates fluctuations in methane concentration.

[0114] This observation method can effectively observe the rate of greenhouse gas exchange in the ocean and avoid the impact of ship swaying on the shipborne observation system. Starting from the atmosphere, it captures high-frequency changes in greenhouse gas concentration, directly providing the rate of greenhouse gas absorption in the ocean, thus developing marine greenhouse gas observation technology, improving observation efficiency, and reducing observation errors.

[0115] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0117] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0118] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0119] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mobile shipborne observation system, characterized in that, It includes an ultrasonic anemometer, a closed-circuit measurement system, an auxiliary meteorological observation system, a motion monitoring system, and a data processing and storage unit; An air inlet is provided near the support arm of the ultrasonic anemometer, and the air inlet is connected to the closed-circuit measurement system through a polytetrafluoroethylene tube. The closed-circuit measurement system is installed in the cabin on the foredeck; the closed-circuit measurement system includes a drying tube, a first vacuum pump, a gas analyzer, and a second vacuum pump connected in sequence; the gas analyzer is used to measure the concentration of carbon dioxide and methane in the sea surface air; The auxiliary meteorological observation system is located at the top of the meteorological mast at the bow; A stainless steel pipe extending along the sea surface is installed at a predetermined first distance between the meteorological mast and the foredeck; the predetermined first distance is determined by the height of the foredeck above the sea surface and the vertical wind speed at the sea surface. The ultrasonic anemometer is installed at one end of the stainless steel tube and is used to observe the three-dimensional wind speed at the sea surface. The motion monitoring system is installed at the junction of the stainless steel pipe and the meteorological mast, and is used to observe the motion data of the ultrasonic anemometer as it moves with the ship. The data processing and storage unit is communicatively connected to the ultrasonic anemometer, the gas analyzer, the auxiliary meteorological observation system, and the motion monitoring system, respectively.

2. The mobile shipborne observation system according to claim 1, characterized in that, The air inlet is equipped with a first filter for filtering liquid water, and the first filter is equipped with a heating device.

3. The mobile shipborne observation system according to claim 1, characterized in that, The auxiliary meteorological observation system includes air temperature and humidity sensors, solar radiation sensors, sea surface temperature sensors, and wind speed and direction sensors; A stainless steel pipe is installed at the top of the meteorological mast, and the air temperature and humidity sensor, the solar radiation sensor, the sea surface temperature sensor, and the wind speed and direction sensor are sequentially installed on the stainless steel pipe at the top of the meteorological mast. The sea surface temperature sensor is installed at an angle towards the sea surface at the bow of the ship.

4. The mobile shipborne observation system according to claim 1, characterized in that, A three-way valve and a second filter are connected sequentially between the first vacuum pump and the gas analyzer; The second filter is used to filter solid particles and liquid water.

5. The mobile shipborne observation system according to claim 1, characterized in that, It also includes: calibration devices; The calibration device is connected to the gas analyzer and is used to calibrate the gas analyzer.

6. The mobile shipborne observation system according to claim 1, characterized in that, The gas analyzer is specifically a Picarro series model, and the sampling frequency of the gas analyzer is 10Hz; The ultrasonic anemometer is specifically a Gill WindMaster Pro series model; The drying tube is specifically a Nafion drying tube.

7. The mobile shipborne observation system according to claim 1, characterized in that, The first vacuum pump has a pumping speed of 20 L / min, and the second vacuum pump has a pumping speed of 5 L / min.

8. The mobile shipborne observation system according to claim 2, characterized in that, The first filter is made of a hydrophobic material, specifically a Teflon membrane filter.

9. The mobile shipborne observation system according to claim 4, characterized in that, The second filter is specifically a disc filter.

10. A method for shipborne observation while underway, characterized in that, The observation methods include: The three-dimensional wind speed at the sea surface is observed using an ultrasonic anemometer; the motion data of the ultrasonic anemometer as it moves with the ship is measured using a motion monitoring system; and the concentrations of carbon dioxide and methane in the sea surface air are measured using a gas analyzer. Based on the motion data, the three-dimensional wind speed is corrected to generate the true three-dimensional wind speed of the sea surface; The shipboard greenhouse gas absorption rate is generated based on the observed three-dimensional wind speed, the carbon dioxide concentration, and the methane concentration.

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