Why do typhoons often occur in Shantou?

Because Shantou is located in a low-latitude coastal area, it has a subtropical climate and a high average temperature

1. First, let’s talk about the conditions for the formation of typhoons. First, there must be a vast atmosphere with high temperature and high humidity. The temperature and humidity of the bottom atmosphere on the tropical ocean surface are mainly determined by the sea surface water temperature. Typhoons can only form on the tropical and subtropical ocean surface where the sea temperature is higher than 26℃-27℃, and the seawater temperature within 60 meters depth is higher. At 26℃-27℃; secondly, there must be an initial disturbance in which the lower atmosphere converges towards the center and the upper atmosphere diffuses outward. Moreover, high-level divergence must exceed low-level convergence to maintain sufficient updraft and low-level disturbances to continue to strengthen. Third, the wind speed in the vertical direction cannot differ too much, and the relative movement of the upper and lower air is very small, so that the water vapor condensation released in the initial disturbance can be released. The latent heat energy is concentrated and stored in the air column in the typhoon eye area, forming and strengthening the typhoon warm center structure; fourth, there must be a large enough geostrophic deflection force, and the earth's rotation is conducive to the generation of cyclonic vortices. The geostrophic deflection force is close to zero near the equator and increases toward the north and south poles. Typhoons occur on the ocean surface about 5 latitudes or more from the equator. 2. Understand these interrelated reasons that cause the diverse paths of typhoons, and our country can actually know that the paths that affect the movement of typhoons in our country (mainly due to factors such as the complex atmospheric environment during the movement of typhoons in the atmosphere.) In our country, The path mainly has 4 points of westward movement. After the typhoon is generated from the ocean east of the Philippines, the surrounding basic airflow is very weak. At this time, the movement of the typhoon center is mainly due to internal force movement, and the direction is northwest. Due to the influence of the high-altitude subtropical high, the deep easterly airflow will guide the typhoon to move westward until it makes landfall along the western coast of Guangdong, Hainan Island or Vietnam. Typhoons moving along this path have the greatest impact on the coastal areas of Hainan, Guangdong, and Guangxi in my country, and often occur in spring and autumn. After a typhoon on a northwest-moving path is generated in the waters east of the Philippines, it will encounter a southerly wind with an axis from northwest to southeast. Under the guidance of this deep airflow, the typhoon moves northwest from the ocean east of the Philippines, lands in Taiwan through the Bashi Strait, and then It will cross the Taiwan Strait and approach the coast of eastern Guangdong or Fujian, and land on the coasts of Taiwan, Fujian, and Guangdong. If the typhoon starts at a higher latitude, it will pass through the Ryukyu Islands, land on the coasts of Zhejiang, Shanghai, and Jiangsu, and even reach Shandong and Liaoning. Typhoons moving along this path have the greatest impact on my country's Taiwan Province, eastern Guangdong Province and Fujian Province. Such typhoons are more common from the second half of July to the first half of September. Turning path: After the typhoon originates from the ocean east of the Philippines, it moves northwest. When it encounters the obstruction of the Western Pacific sub-high pressure or westerly trough at sea, it turns northeast and moves toward the Korean Peninsula or Japan. This kind of turning typhoon can be divided into three categories: east turning, medium turning, and west turning. Among them, the west-turning type, especially the typhoons that turn westward when they reach the offshore area, turn to the northeast after landing in the coastal areas of my country, and the path is parabolic, which is also the most common path. Typhoons moving along this path have the greatest impact on my country's eastern coastal areas. Such typhoons mostly occur in summer and autumn. However, the latitude of the turning point varies with the season. It is in the far north in midsummer and in the far south in spring. Special path: When the environmental situation of a typhoon changes rapidly, or there are multiple typhoons interacting with each other at sea, the moving path of the typhoon will become weird. It is like a top being affected by external forces when rotating, and the center will move. Cyclonic arc motion. When this movement happens to be in the opposite direction to the original movement, it will cause the typhoon to stagnate and spin. If the external force it receives is unbalanced, it will sway from side to side, like a moving snake. Such movement paths are complex and difficult to predict, making them more likely to cause disasters. For example, Typhoon "Lily" that occurred in 2001 followed a special path. After it was generated, it slowly circled in place on the northern sea surface of Taiwan like a snake and then landed near Yilan, Taiwan, wreaking havoc. It took 44 hours to reach the Taiwan Strait, and finally landed again in Chaoyang and Huilai, causing serious disasters and great losses to the local areas. Its weird path leaves a deep impression on people.