Breakthrough in research on ocean turbulent heat flux, contribution to new ocean detection technology

The channel for heat exchange between the ocean and the atmosphere is the sea-air interface. At present, the technology for observing the atmospheric boundary layer at the sea-air interface is very mature. However, due to limitations in observation technology and means, researchers still do not know how heat is transported in the upper boundary layer of the ocean. Heat transfer in the ocean is mainly accomplished through seawater turbulence, and previous studies have pointed out that small-scale seawater turbulence has a strong ability to transport heat in the vertical direction, and is crucial to the temperature of seawater and sea-air heat exchange. influence. Therefore, heat flux observation of seawater turbulent microstructure has become the key to the study of heat transport in the upper boundary layer of the ocean.

In order to solve the limitations of direct observation of ocean heat flux in terms of sensor accuracy and sensitivity, the research team of the South China Sea Institute of Oceanography, Chinese Academy of Sciences previously developed the Ocean Detection Rapid Temperature Detection System. Based on the sensor, combined with the acoustic Doppler three-dimensional point velocity meter (ADV), we independently developed an ocean heat flux meter, which can observe the heat flux, momentum flux, and end kinetic energy dissipation of turbulent flow at the same point. efficiency and heat dissipation rate, and can work under water of 1-5000 meters.

Among them, ADV is used to measure the three-dimensional flow velocity of the turbulent field in the ocean, and the ocean detection fast temperature sensor is used to measure the temperature of the ocean turbulent field. The combination of the two can measure the turbulent field in the ocean at the same time and at the same point. Velocity field and temperature field. Then the ADV attitude data is used to correct the flow velocity data, and the method of measuring the vertical turbulent heat flux of the ocean based on the covariance of the vertical velocity pulsation and the temperature pulsation realizes the measurement of the turbulent heat flux below the sea surface.

The research team used an ocean heat flux instrument to observe seawater turbulence off the coast of Sanya and the northern part of the South China Sea. It measured underwater heat flux for the first time, and analyzed the data based on the observations. The role of ocean turbulent eddies in wind and wave areas on heat flux transport. It was also determined that turbulent heat flux and momentum flux are closely related to semidiurnal tides and diurnal tides, with the former reaching during the low tide period and the latter during the ebb tide period, thus indicating the connection between tidal and vertical turbulent fluxes.

In addition to observing the heat flux of seawater turbulence, researchers also said that the ocean heat flux instrument can be used to observe heat flux in deep-sea hydrothermal areas. Deep sea hydrothermal areas are rich in marine biological resources and mineral resources, all of which rely on the eruption of seafloor hydrothermal fluids. There is currently no mature technical solution to achieve heat flux measurement in deep-sea hydrothermal areas. However, after improvements and improvements are made to the ocean heat flux instrument, it is hoped that it can become aThe solution to this problem.

The development of ocean heat flux instrument enables the monitoring of seawater heat flux. Researchers can use this to quantitatively study the heat absorbed by the ocean from the atmosphere and solar radiation and the heat fed back by the ocean to the atmosphere. Heat, thereby gaining a deeper understanding of climate change patterns, establishing a more realistic climate model, improving ocean forecasting capabilities, and promoting the development of climate research.

The observation of ocean turbulence microstructure has attracted more and more attention in recent years. European and American countries and Japan have made a series of progress in the research of turbulence microstructure profilers and formed a series of products. Domestic research on ocean turbulence microstructure profilers has just started. The successful development of ocean heat flux meters is also a major progress in my country's ocean turbulence research instruments. It not only completed fixed-point ocean turbulence mixing observations, but also took the lead in realizing underwater heat flux. Quantitative measurements have enabled our country to make significant progress in ocean turbulence research. With the improvement of ocean heat flux instruments, my country will achieve greater results in the field of ocean heat flux research.

Source: Science Today

Editor’s comment: Thanks to advanced science and technology, scientific researchers have developed many sophisticated instruments and equipment , and played an active role in unlocking and solving various puzzles. Faced with the observation of ocean turbulence microstructure, researchers have developed an ocean heat flux meter, which is a great progress for ocean flux research. In the future, I believe that with the help of science, our research on the ocean will be more advanced. For the depth.

　(Original title: Breakthrough in research on ocean turbulent heat flux, contribution to new ocean detection technology)