Xinhua News Agency's "Snow Dragon 2", December 29 (Reporter Zhou Yuan) The "Snow Dragon 2", which carried out China's 40th Antarctic expedition, sailed to the westerly wind belt on December 28. On the stern deck, a black oval instrument is thrown into the sea, and data is continuously transmitted back through a copper wire connected to it.
This is a disposable thermohaline bathymetry, which mainly measures the temperature, salinity and other data of seawater. Peng Tengteng, a member of the expedition, said.
Why measure seawater temperature and salinity?Shi Jiuxin, a member of the expedition team and a professor at Ocean University of China, believes that we must start with seawater. The flow of seawater in the ocean forms a large conveyor belt that circulates heat and matter through the world's oceans, becoming a key link in regulating the global climate system.
The temperature and salinity of seawater, like human body temperature and weight, are the most basic data of the physical ocean, which directly reflects the changes in the marine environment and affects the flow of seawater. Shi Jiuxin said.
On November 25, 2023, the "Snow Dragon 2" (front) and the "Tianhui" ship are traveling through the westerly wind belt together (drone**) Xinhua News Agency (photo by Chen Dongbin).
In the disaster sci-fi film "The Day After Tomorrow", it is precisely because of the abnormal sea temperature and salinity that the Atlantic meridional overturning circulation suddenly weakens, the ocean circulation conveyor belt stops, and the supply of warm currents from the equatorial tropics is interrupted, causing the temperature in the northern hemisphere to plummet.
The temperature and salinity of the polar oceans are of particular concern.
In the global ocean circulation, the most significant and important ocean sinking movements occur in the polar oceans, which become the drivers of the oceanic conveyor belt. Shi Jiuxin further explained that taking the Antarctic coast as an example, the sinking high-density sea water forms the Antarctic bottom water, which spreads northward along the ocean basin and enters the Atlantic, Pacific and Indian Oceans.
Shi Jiuxin said that the temperature and salinity of seawater determine the density and affect the sinking process of seawater. If the sinking process of the polar oceans slows down or stops, it will have catastrophic effects on the climate.
Surveys of seawater temperature and salinity are a long-term and continuous process.
The hydroenvironmental survey began with a westerly wind belt at latitude intervals of 0At 25 degrees, a disposable thermohaline depth meter is put into place, and it is expected that 70 will be put into it. In Peng's view, only by accumulating years of continuous data can it be possible to solve the corresponding scientific problems from these data.
The hydrological environment survey carried out during the Southern Ocean voyage can accumulate basic data for further research on the Antarctic front, Antarctic circumpolar current, and other related studies. Peng Tengteng said.
It is reported that this Antarctic expedition will rely on the "Snow Dragon", "Snow Dragon 2" and the research station to carry out a series of comprehensive surveys and monitoring, and deeply study the role of Antarctica in global climate change.