What are the causes of the formation of hot weather

Causes of the formation of hot weather:

1. Solar radiation.

In summer, the direct sun gradually moves from south to north, and on the summer solstice, it hits the Tropic of Cancer directly. In this process, the solar altitude angle in the Northern Hemisphere gradually increases, the sunshine hours continue to increase, the received solar heat gradually increases, and the temperature also increases. This is the basic reason for the formation of hot weather.

2. Atmospheric circulation.

On the one hand, specific circulation situations are prone to high temperatures. A typical example is the subtropical high, which has the title of "high temperature messenger". In the middle of summer, the western Pacific subtropical high controls the middle and lower reaches of the Yangtze River in China, and the air warms strongly due to the prevailing downdraft in the subtropical high.

At the same time, the weather is sunny and cloudless, which is conducive to sunlight, and the ground radiation temperature is significantly warmed, which is easy to form high temperature and hot weather. In addition, weather systems such as continental warm high pressures, tropical cyclones, thermal low pressures, and weak cold fronts will also generate high temperature and heat waves.

On the other hand, atmospheric circulation anomalies also have a direct impact on the formation of high temperature weather. For example, if the position and intensity of the subtropical high are abnormal, it will cause changes in high temperature weather.

3. Geographical factors.

The geographical location, topography, landform and other characteristics of a place also affect the level of temperature. For example, Nanjing, Wuhan and Chongqing, the three major furnace cities that have appeared in China's "history".

They all belong to basin-like terrain, which is easy to store heat and not easy to dissipate heat, which helps to form hot weather. For example, due to the high altitude, some areas such as the Qinghai-Tibet Plateau have not experienced high temperature weather.

4. Global warming.

Due to the influence of human activities and natural fluctuations in the climate, the global average surface temperature has been on an increasing trend for more than 130 years. Over the past few decades, each decade has seen temperatures significantly warmer than the previous one. Under the influence of global warming, extreme heat events are also becoming more frequent.

5. Urban heat island effect.

Due to the dense population and large building area of the city, the humidity and air convection of the urban surface have changed, resulting in a significantly higher temperature in the city than in the surrounding area.

Nowadays, with the acceleration of urbanization, the urban heat island effect is more obvious, which plays a role in the formation of hot weather.

Subtropical high pressure.

The formation of high temperatures is often directly caused by specific weather systems, the most typical and common of which is the subtropical high, which has the title of "high temperature messenger".

From the mouth of the weather forecast host, we often hear commentary such as "With the strengthening of the sub-high, China's Jiangnan, South China and other places will usher in a round of high temperature weather", especially in summer.

1. Natural causes: At present, the earth is in an interglacial period between two glacial periods, and the temperature has a rising trend, but the warming rate is slow.

2. Anthropogenic causes: carbon dioxide.

The specific gravity rises, absorbing a large amount of infrared rays released by the ground.

Long-wave radiation causes the temperature to rise rapidly, producing a greenhouse effect.

The original closed causes of the increase in carbon dioxide are:

1) Industry, transportation, and household stoves burn a large amount of coal, oil, natural gas and other fossil fuels, producing a large amount of carbon dioxide.

2) Indiscriminate deforestation, forests, especially tropical forests, have been destroyed, so that the carbon dioxide absorbed and fixed by the forest has been rapidly reduced.

The reasons for the persistent hot weather are as follows:The first is the impact of atmospheric circulation anomalies.

In the summer, the atmospheric global system exhibited a consistent warm high-pressure circulation system control, forming a wide range of the overall global warm high-pressure belt Under the influence of the high-pressure system, the hot air will remain on the ground, and if it does not disperse, it will make the place very hot.

The second reason is that the three-year La Niña climate event has contributed to the atmospheric circulation anomaly.

The third reason is the amplification and regulation of global warming.

In fact, in recent years, the instability of the global climate system has intensified, with frequent occurrence of extreme weather and climate events, and the occurrence of widespread, intense, and concurrent climate anomalies has become more persistent and frequent, and more regions are experiencing more compound extreme events. The continuous high temperature weather has brought many adverse effects to human health and agricultural production.

Subtropical high pressure.

The formation of high temperatures is often directly caused by specific weather systems, the most typical and common of which is the subtropical high, which has the title of "high temperature messenger".

From the mouth of the weather forecast host, we often listen to the dust to "With the strengthening of the sub-high, China's Jiangnan, South China and other places will usher in a round of high temperature weather", especially in the summer nuclear combustion.

The sun is relatively close to the earth, and there is a greenhouse effect that is becoming more and more important.

There are three fundamental reasons why the high temperature weather in China has lasted for a long time this year, which has led to such a hot temperature this year. , which is heavily affected by atmospheric circulation anomalies. This year, there is a consistent phenomenon in the atmospheric circulation system, resulting in the warm subtropical high circulation system controlling the vast area in the central and eastern parts of China, forming a large range of global warm high pressure belts, staying in this area for a long time, resulting in the long-term control of the subtropical high pressure system, so that the hot air stays on the ground for a long time, and it is difficult to spread, which will make these areas in a long-term hot weather state. The influence of La Niña climate in the past three years has played a role in promoting the anomaly of the subtropical high temperature atmospheric circulation, so that the current subtropical high temperature has been stranded in the central and eastern parts of China for a long time, and it has not been affected by other atmospheric circulation for a period of time, so that such a long period of high temperature, high humidity and hot weather conditions have occurred. The long-term high temperature weather was amplified and regulated by global warming, resulting in a long period of very hot weather in the central and eastern parts of China. It is no secret that huge anomalies have occurred in the global climate system in recent years, which have continued to exacerbate the instability of the global climate system, resulting in frequent extreme weather.