Ride the wind and waves towards the deep sea

2015 China-Indonesia Joint Voyage Expedition (Yuan Dongliang in the third from the left). Courtesy of the research team

■ Reporter Zhang Shuanghu

The Western Pacific Ocean is home to the warm pool, the highest water body in the world, where the global ocean conveyor belt flows, bringing solar radiation heat to high latitudes and exerting an important impact on the global climate.

Beginning with the "Thirteenth Five-Year Plan", China began to conduct large-scale investigation and research on the western Pacific. With the support of the National Natural Science Foundation of China Innovation Research Group Project "Dynamic Process of Ocean Circulation in the Western Pacific Ocean" (hereinafter referred to as the Innovation Group Project), Yuan Dongliang, a researcher at the Institute of Oceanography of the Chinese Academy of Sciences (hereinafter referred to as the Institute of Oceanography of the Chinese Academy of Sciences), led the innovation group to achieve important breakthrough results: it discovered the longest and strongest extra-equatorial extra-equatorial substituent undercurrent, the North Equatorial Subsurface Current, which is the longest and strongest extra-equatorial extra-equatorial submarine current across the North Pacific Basin, revealing its path into the Indonesian Sea and the dynamic mechanism, correcting the existence of the classical theory "shadow zone" The discovery of two new branches of the Indonesian circulation, which connects the Pacific and Indian Ocean circulations, provides a new pattern understanding for the Pacific-India exchange and the global ocean conveyor belt; and reveals the impact of the interaction of the Black Tide and the offshore circulation of the Western Boundary Flow of the North Pacific Subtropical Circulation on China's coastal environment. The international cooperation program of THE NPOCE (Northwest Pacific Ocean Circulation and Climate Experiment), initiated and led by the team, has been highly recognized by the international academic community.

Sea

On the morning of November 21, Qingdao Xuejia Island Wharf.

With a long whistle, the "Science" research ship slowly left the port and rushed to the western Pacific ocean to implement the National Natural Science Foundation of China's shared voyage plan this year.

The Science gradually sailed toward the vast sea, getting smaller and smaller, and finally disappeared into the horizon. At the same time, China's oceanographic research is moving towards deep blue step by step...

In the next 80 days, the scientific expedition team of more than 30 people will recover the subdissive targets laid last year, collect observational data, maintain and re-deploy the submersible targets, and carry out multidisciplinary investigations of physics, chemistry, biology, geology and other disciplines in accordance with the standards of the international GO-SHIP program.

"Every time you go to sea, there are new challenges." Zhang Linlin, the person in charge of the voyage and a researcher at the Institute of Oceanography of the Chinese Academy of Sciences, told China Science News, "In the early stage of the sea expedition, the institute will hold a ceremony, the leader's speech, media reports, colleagues farewell, the ceremony is short and solemn. In recent years, these ceremonies have been omitted, and everyone has just shook hands and emphasized safety matters. ”

Because the scientific expedition team made full preparations before going to sea, they repeatedly thought and discussed the design plan, and they had a bottom in their hearts.

Ocean circulation research is highly dependent on observation, and one of the important tasks of the expedition team is to obtain measured data on the state of the ocean, including the laying and recovery of deep-sea submarine markers for long-term sequence observations.

"We didn't do this in the first place." Yuan Dongliang told China Science Daily, "The laying of more than 6,000 meters of deep-sea submarine markers in the turbulent western boundary stream was also the first time in the world at that time, including how the observation system was designed, how to operate at sea, and what technical scheme was adopted, and there was no experience to learn from." ”

After countless discussions, designs, attempts and modifications, the team finally came up with a mature observation scheme.

A set of submersible observation systems, like a huge string of pearl necklaces, hung quietly in the sea. On the "rope" about 6 kilometers long, the bottom end is a heavy object of nearly two tons, which fixes the submarine marker on the seabed, and along this rope upwards, an instrument and a float are set up at intervals to keep the submarine in the sea upright and "standing". More than 30 expensive instruments and equipment hang on the submerged markers to monitor ocean currents, water temperature, salinity and other data.

In the ocean of "windless three feet of waves", it is not easy to make this "big necklace" weighing nearly two tons stand in the sea. The expedition team members first put down the float, and then started the expedition ship at a low speed, hanging the instrument while advancing, adjusting the state, and carefully putting it into the sea.

"Offshore operations are very complicated, wind direction, ocean currents must be fully considered, otherwise the ropes released swing around, if you touch the instrument, wear the rope will lead to failure." Hu Shijian, another member of the Innovation Group Project and a researcher at the Institute of Oceanography of the Chinese Academy of Sciences, told China Science Daily, "Every time the submarine marker is deployed, the scientific expedition team members have to work on the deck for seven or eight hours continuously." After using the advanced Science survey vessel, it can be controlled within three or four hours at a time. ”

"This whole set of things put into the sea, counterweights, floats, instruments, ropes and connecting parts of each part, no link can be wrong, any small problem may lead to the subtext can not be recovered, or can not get the data they want." Yuan Dongliang said, "Therefore, this is not only a technical work, but also a test of physical strength, patience, care and teamwork ability." ”

Course

In the 1960s, international oceanographic research entered the stage of large-scale marine stereoscopic observation experiments, but due to factors such as funds, technology, instruments and equipment, China's oceanographic research was still in the exploratory stage as a whole, and even the conditions for "following and running" were not available.

In 2009, Hu Dunxin, the founder of China's West Pacific Ocean Circulation Research and an academician of the Chinese Academy of Sciences, was funded by the National Natural Science Foundation of China for major projects, opening a new round of Western Pacific Circulation Scientific Expeditions against the background of 15 years of stagnation in the international large-scale Western Pacific research expeditions.

In 2011, Yuan Dongliang served as the chief scientist of the Western Pacific Open Sharing Voyage of the National Natural Science Foundation of China, led a team to the Western Pacific to carry out scientific investigations, successfully completed various tasks, and since then opened a 10-year-long chapter of scientific expeditions in the Western Pacific.

"In the early days, under the leadership of Academician Hu Dunxin, we explored and carried out submarine target observations and research, laying the foundation for the later acquisition of innovative group projects." Yuan Dongliang said, "At that time, the submarine marker was very expensive, and only one set (submarine marker) was only deployed or recycled every time he went to sea. ”

In 2014, China began to deploy submarine markers on a large scale in the western Pacific Ocean and the Indonesian Sea. At this time, the innovative group project team led by Yuan Dongliang has rich experience and "is more confident". At the end of 2015, when Yuan Dongliang, the leader of the innovation group project, led the team to recover the submersible markers, China had deployed 16 sets in the western Pacific Ocean and 5 sets in the Indonesian sea, forming an observation array composed of more than 20 sets of submersible targets. This change in magnitude has laid the foundation for China to carry out continuous observation and research on the ocean.

Since then, Yuan Dongliang has led the construction of the Indonesian sea observation system, and by 2018, it has formed a scale of more than 10 sets of Indonesian seas and more than 20 sets of western Pacific oceans. At present, China has more than 30 sets of synchronous submarines in the western Pacific Ocean and the Indonesian Sea, observed a large amount of precious data, discovered many unprecedented new phenomena, and achieved a number of important results.

"We take it step by step, and every time we have a big challenge." Hu Shijian said, "After more than 10 years of exploration, some of our theories and research methods have become a paradigm and have become a reference for other research teams in the world. ”

cooperate

"We've done a lot of work on international cooperation." Yuan Dongliang said, "Not only leading the NPOCE international cooperation program, but also building a submarine target array covering key straits in Indonesia's inland sea, and obtaining the ocean observation data that only China has in the world." ”

To study the Indonesian translucency, observations must be made in Indonesia's inland sea, which must be achieved through international cooperation. Yuan Dongliang said, "Through international conferences and academic training and other activities, we have established a trusting partnership with Indonesian scientists, through a lot of communication, and innovative cooperation paradigms, using Indonesian research vessels to complete the construction of the Indonesian submarine array." ”

Working on an Indonesian research vessel, researchers not only have to overcome the difficulties brought about by natural conditions, but also adapt to local life and habits. Li Yao, a member of the Innovation Group Project, once experienced the thrill of tracking stolen navigational beacons in the high temperature of the deck at 40 to 50 degrees Celsius in the equatorial region, because the shirt buttons were open and exposed to bubbles, and Wang Jing, a member of the Innovation Group Project and chief scientist, experienced the thrill of tracking stolen navigation markers...

"These young people have grown up very fast, and they have faded the 'youthful energy' of their fledgling years." Yuan Dongliang said, "Two of them have been funded by the National Natural Science Foundation of China Outstanding Youth Science Foundation project, and 8 of them have served as voyage or section chiefs, and they can be sent out to be independent." ”

China Science Daily: What is the significance of studying ocean currents and clarifying the laws and mechanisms of ocean currents?

Yuan Dongliang: Ocean circulation is an important carrier for the global transmission of matter and energy, especially heat transport. The western Pacific warm pool directly affects the water vapor transport along the southeast coast of China, and plays an important role in the study of medium- and long-term climate change and short-term climate prediction in China. In addition, the understanding and study of the ocean is important for national environmental security, and at the same time, it is convenient for people to develop the ocean and better serve economic and social development and the progress of human life.

China Science Daily: What is the current level of china's ocean current research in the world?

Yuan Dongliang: In marine research, China has made great progress in observation methods, research methods and instruments and equipment, and has also achieved a number of important results. Over the years, we have worked closely with Indonesia to obtain a lot of valuable observational data. In the western Pacific-Indonesian Sea, we are generally at the forefront of the world.

China Science Daily: What are our research plans for the next step?

Yuan Dongliang: In 2007, the Chinese Academy of Sciences organized the study of "Roadmap for the Development of China's Marine Science and Technology by 2050", and I am a planner and main writer in the field of marine environment. According to the roadmap, by 2020, we have achieved the goal of laying an observation array in the western Pacific-eastern Indian Ocean to form a local research advantage; in the next step, by 2035, we plan to expand the observation network to the entire Indo-Pacific Basin. At present, there are already some international plans in the Pacific Ocean, and we will strengthen international cooperation, form a "cross" observation network and participate in the international tropical Pacific observation system TMOS program; by 2050, the development of our country will inevitably require us to expand ocean observations to the world. At that time, we will connect the world's oceans to form a "complete story.".

Source: China Science Daily