1:45 PM - 3:15 PM
[O11-P98] Do Melting Glaciers Stop Deep Ocean Currents?
Keywords:Sea, Environment
Deep currents are ocean currents that originate in the North Atlantic Ocean, pass through the equator, Indian Ocean, and Pacific Ocean, and circle the oceans over several thousand years. It is believed that the main cause of deep currents is the cooling of the sea surface by the atmosphere around the North Atlantic Ocean, which separates the salty water from the fresh water ice, and the denser water settles down. Deep-ocean currents are also responsible for heat transport from low-latitude regions to high-latitude regions because of their circulation.
However, there are concerns that the circulation speed of the deep-ocean currents may slow down or even stop due to global warming, which has recently been recognized as a problem. The reason for this is that the deep current is caused by the difference in salinity in the North Atlantic, and the melting of glaciers causes freshwater to flow in and dilute the salinity of seawater, making it more difficult for the seawater to settle out. It has been suggested that the cessation of deep-ocean currents would impede the movement of underwater organisms and stop the transfer of nutrients and heat, potentially leading to a cold season. Therefore, we believe that conducting replicated experiments on the cessation of the deep-ocean current under different conditions and producing results will provide an approximate indication of how much glacier melting is required to stop the circulation. Therefore, we feel that this research is very significant. We also hope that our research will help increase awareness of global warming.
The theme of this research is to reproduce the cessation of deep ocean currents due to global warming. Therefore, we focused on how well we could reproduce the actual environment of the Atlantic Ocean. Not only water temperature and salinity, but also the way the deep ocean currents flow in the Atlantic Ocean were imitated as warm and cold currents with reference to Mr. Blocker's conveyor belt. Specifically, the left side of the tank is considered to be off Greenland, and the right side is off France. The reason why the right side of the tank is defined as off the coast of France is that the ocean currents between the coasts of France and Greenland, except for the currents around Iceland, do not refract in a complicated manner, and are therefore easy to imitate. In accordance with the blocker conveyor belt, the Greenland side is filled with dense, cold salt water, while the opposite side is filled with relatively warm salt water on the surface to create a U-shaped flow. Greenland sinks when cooled by the atmosphere, but it is difficult to actually cool the water surface using the atmosphere, so ice with the same density as the salt water in the tank is prepared and placed on the surface of the Greenland side. We will use vitamin B2, which is relatively insoluble in water, instead of ink, which is highly water soluble, for visualization of the current. This is because our seniors used vitamin B2 in their experiments on deep ocean currents, although the theme was different. The vitamin B2 is placed on the right side of the tank, which is the starting point of the deep-ocean current.
The vitamin B2 is placed on the right side of the tank, which is the starting point of the deep current in this tank, for observation. The deep current is caused by differences in salinity and water temperature, so when the current is generated in the tank, freshwater ice is floated on the surface of the water on the Greenland side where the salt water is settling to stop the current.
The various conditions of the experiment are described below. First, we decided to judge the cessation of the deep-ocean current based on the velocity of the current. Specifically, we compared the case in which the deep-ocean current was intentionally stopped using freshwater ice and the case in which it was not stopped, and judged that the current had stopped when the velocity became 1/100th of the velocity without stopping. The criteria will be determined in the course of the assumed experiments.
In addition, we will calculate the amount of heat given to the water surface by the indirect lighting used in the experiment to stop the deep-ocean current and verify the effect of the indirect lighting on the temperature change of the salt water before conducting the experiment to stop the deep-ocean current.
However, there are concerns that the circulation speed of the deep-ocean currents may slow down or even stop due to global warming, which has recently been recognized as a problem. The reason for this is that the deep current is caused by the difference in salinity in the North Atlantic, and the melting of glaciers causes freshwater to flow in and dilute the salinity of seawater, making it more difficult for the seawater to settle out. It has been suggested that the cessation of deep-ocean currents would impede the movement of underwater organisms and stop the transfer of nutrients and heat, potentially leading to a cold season. Therefore, we believe that conducting replicated experiments on the cessation of the deep-ocean current under different conditions and producing results will provide an approximate indication of how much glacier melting is required to stop the circulation. Therefore, we feel that this research is very significant. We also hope that our research will help increase awareness of global warming.
The theme of this research is to reproduce the cessation of deep ocean currents due to global warming. Therefore, we focused on how well we could reproduce the actual environment of the Atlantic Ocean. Not only water temperature and salinity, but also the way the deep ocean currents flow in the Atlantic Ocean were imitated as warm and cold currents with reference to Mr. Blocker's conveyor belt. Specifically, the left side of the tank is considered to be off Greenland, and the right side is off France. The reason why the right side of the tank is defined as off the coast of France is that the ocean currents between the coasts of France and Greenland, except for the currents around Iceland, do not refract in a complicated manner, and are therefore easy to imitate. In accordance with the blocker conveyor belt, the Greenland side is filled with dense, cold salt water, while the opposite side is filled with relatively warm salt water on the surface to create a U-shaped flow. Greenland sinks when cooled by the atmosphere, but it is difficult to actually cool the water surface using the atmosphere, so ice with the same density as the salt water in the tank is prepared and placed on the surface of the Greenland side. We will use vitamin B2, which is relatively insoluble in water, instead of ink, which is highly water soluble, for visualization of the current. This is because our seniors used vitamin B2 in their experiments on deep ocean currents, although the theme was different. The vitamin B2 is placed on the right side of the tank, which is the starting point of the deep-ocean current.
The vitamin B2 is placed on the right side of the tank, which is the starting point of the deep current in this tank, for observation. The deep current is caused by differences in salinity and water temperature, so when the current is generated in the tank, freshwater ice is floated on the surface of the water on the Greenland side where the salt water is settling to stop the current.
The various conditions of the experiment are described below. First, we decided to judge the cessation of the deep-ocean current based on the velocity of the current. Specifically, we compared the case in which the deep-ocean current was intentionally stopped using freshwater ice and the case in which it was not stopped, and judged that the current had stopped when the velocity became 1/100th of the velocity without stopping. The criteria will be determined in the course of the assumed experiments.
In addition, we will calculate the amount of heat given to the water surface by the indirect lighting used in the experiment to stop the deep-ocean current and verify the effect of the indirect lighting on the temperature change of the salt water before conducting the experiment to stop the deep-ocean current.