The world is “extremely hot”
At present, the world's most recognized "hot pole" is Basra, located in Iraq, West Asia. Basra is the capital of Basra Province in Iraq. It is located on the west bank of the Shatt al-Arab River at the confluence of the Tigris River and the Euphrates River, 55 km from the Persian Gulf to the south. Kilometers, it is the largest port and the second largest city in Iraq. The measured extreme maximum temperature is as high as 58.8℃. We found that the above-mentioned areas with extremely high temperatures are all located in the subtropical areas near the Tropic of Cancer, rather than in the equatorial areas where the average solar altitude angle is the largest. In other words, whether it can become the "hot pole" of the world's climate depends not only on the size of the solar altitude angle. , it also depends on weather conditions, underlying surface conditions, air movement and other factors.
Near the equator, although the sun's altitude angle is large, the land area is relatively small. It is controlled by the equatorial low-pressure belt, with more updrafts, more convective rain, more clouds and rain, and at the same time, the underlying surface has dense vegetation and a specific heat Large and slow to heat up, the temperature rise near the ground is limited. In the subtropical region, on the one hand, the latitude is lower, the annual average solar altitude angle is relatively large, and it receives more solar radiation. At the same time, it is controlled by the subtropical high pressure all year round, and downdrafts prevail, making it difficult to form clouds and cause rain. The climate is dry and prone to rain. In clear weather, clouds have a weak weakening effect on solar radiation.
On the other hand, due to sparse precipitation and arid climate in subtropical areas, the surface natural zones are often tropical desert zones with sparse vegetation, small physical specific heat, and rapid warming, resulting in high temperatures near the surface. Through the above analysis, we know that the areas with the highest temperatures in the world occur in the continental desert areas between 20 and 30 degrees north and south latitude. Basra in Iraq is located around 30 degrees north latitude and is located in the world's largest desert area in West Asia and North Africa. The climate is hot every summer. , the highest temperature often occurs in July, with the average high temperature above 40 degrees. On July 8, 1921, the highest temperature in the world was measured at 58.8°C.
Reasons for formation: Basra is located in Iraq and has a typical tropical desert climate. It is controlled by the subtropical high all year round, and downdrafts prevail. This results in clear skies all day long, low air humidity, and low rainfall. In addition, The sun shines all year round, and this "heat" cannot be dissipated all year round, so the temperature remains high.
The sand in the desert has a small specific heat ratio, the temperature rises quickly during the day, has a strong heat storage capacity, and the heat is not easily transferred underground.
The northeast trade wind here is an offshore wind blowing from the vast Eurasian continent. It is hot and has little water vapor content, and cannot increase precipitation.