What is the reason behind the abnormal weather?

Scientists tell us that there are many reasons that affect the weather change, but one of the most important factors is the ocean.

Anyone who has seen the sea knows that the ocean is not a stagnant pool, it is always flowing. There are many reasons why seawater flows. The most widely known is that there are regular high and low tides in the offshore waters every day, including the famous Qiantang River Tide. In addition, there are sea currents caused by sea breeze, such as the south equatorial current and the north equatorial current flowing westward in the middle of the Pacific Ocean and the Atlantic Ocean, and the northbound current caused by the southerly winds in west wind drift, Australia and the west coast of South America.

The current formed by the difference of seawater temperature and salinity is called thermohaline circulation, in which the current from high water temperature to low water temperature is called "warm current" and vice versa. The famous Gulf Stream is the largest warm current in the world. It gathers warm seawater with high salinity from the north equatorial current and the south equatorial current, and flows to the North Atlantic along the east coast of North America, bringing heat to the passing area. When the warm current reaches the middle and high latitudes, the water temperature and salinity will decrease, which will cause the density of seawater to increase and sink, and then flow back to the tropics along the coast, forming an ocean circulation.

The flow of seawater changes the distribution of ocean temperature, thus affecting weather and climate. According to satellite observation data, scientists found that 74% of the global heat transported from the tropics to high latitudes via 20 north latitude is transported by ocean currents, which exceeds the heat transported by the warm air mass. In the sea area where the warm current passes, the climate becomes warm and humid, and a large area of high-temperature seawater is one of the important reasons for typhoons along the southeast coast of China every summer. In the sea area controlled by cold current, the weather is cold and dry, which makes the land along the way prone to drought and even become desert.

The circulation of warm current and cold current in the ocean forms a "global heat conveyor belt"

For example, there is a warm current from the southeast of the Philippines in the northwest Pacific Ocean, which is called "Kuroshio" because the current speed is as fast as the tide and the water is as dark blue as ink. Go north along the east side of bashi channel and enter the East China Sea via the northern part of Taiwan Province Province. The flow of Kuroshio is equivalent to 300 times that of the Yangtze River into the sea. As it comes from warm tropical areas, the temperature of seawater is much higher than that of surrounding seawater, which is 27 ~ 30℃ in summer, and even in winter, the surface water temperature is not lower than 20℃.