Why is it so hot?

1. There are two main reasons for summer heat. One is that the sun is located in our hemisphere, so the sun has a large elevation angle and strong solar radiation. The other is that the days are long in summer and there are many natural lights. In summer, the sun is close to the Tropic of Cancer, and China is in the northern hemisphere. In summer, it will naturally be hot in these months. However, countries in the southern hemisphere, such as Australia and New Zealand, have the opposite climate to the northern hemisphere. In summer in the northern hemisphere, the direct point of the sun is located in the northern hemisphere, and the solar altitude angle (the intersection angle between the sun's rays and the ground level) is large in all parts of the northern hemisphere. The same amount of solar radiation passes through a relatively short atmospheric path, and less solar radiation is weakened by the atmosphere, so more solar radiation reaches the ground. At the same time, because the height angle of the sun is large, the area scattered by the same amount of solar radiation is small, and more solar radiation is obtained on the ground per unit area. The temperature is higher. Also, in summer in the northern hemisphere, the days are long and the nights are short, with more heat income and less expenditure. In addition, in summer in the northern hemisphere, a thermal depression forms on land, and the high pressure center at sea transports warm and humid air masses to low latitudes, which raises the temperature to some extent. The reason for the sultry air is high humidity. On the one hand, the temperature is high, the evaporation is large, and the water vapor content in the air is high. On the other hand, warm and humid air from the ocean provides more water vapor with high water vapor content, which makes people feel sultry. Just like taking a sauna 2. Because of the greenhouse effect, the greenhouse effect, also known as the "greenhouse effect", is commonly known as the atmospheric heat preservation effect. The atmosphere can make the short-wave radiation of the sun reach the ground, but the long-wave radiation emitted by the ground is absorbed by the atmosphere, which raises the temperature of the ground and the lower atmosphere. Because its function is similar to the greenhouse for cultivating crops, it is named the greenhouse effect. If this effect does not exist in the atmosphere, the surface temperature will drop by about 330℃ or more. On the other hand, if the greenhouse effect continues to strengthen, the global temperature will continue to rise year by year. Since the industrial revolution, carbon dioxide and other heat-absorbing greenhouse gases emitted into the atmosphere by human beings have increased year by year, and the greenhouse effect of the atmosphere has also been enhanced, which has caused a series of serious problems such as global warming and attracted the attention of all countries in the world. Greenhouse has two characteristics: the temperature is higher than that outside, and it does not dissipate heat. Glass greenhouses and vegetable greenhouses that can be seen in life are typical greenhouses. Glass or transparent plastic film is used as a greenhouse, so that sunlight can directly shine into the greenhouse and heat the indoor air, and the glass or transparent plastic film can prevent the indoor hot air from emitting outward, thus keeping the indoor temperature higher than the outside and providing conditions conducive to the rapid growth of plants. The greenhouse effect caused by environmental pollution refers to the phenomenon that the earth's surface becomes hot.