Geographical explanation of rainy nights in Sichuan.

The rainy night in Sichuan Basin is caused by humid air and cloudy sky. Clouds block part of the solar radiation, so the temperature under white clouds is not easy to rise and convection is not easy to develop. At night, clouds can absorb the heat radiated from the ground and then transmit it to the ground in the form of reverse radiation. Therefore, the cloud has a considerable thermal insulation effect on the ground, so that the temperature under the cloud will not be too low at night.

The cloud itself has good radiation heat dissipation ability. Due to radiation heat dissipation, its upper temperature is lower than that under the cloud, forming the characteristics of cold above the cloud and warm under the cloud. So convection occurs at high altitude and low altitude, clouds develop, and rainfall occurs.

Extended data

The general characteristics of climate in Sichuan are: significant regional differences, warm winter in the east, dry spring, hot summer, rainy autumn, cloudy weather, less sunshine, long growing period, cold winter in the west, basically no summer, abundant sunshine, concentrated precipitation and clear dry and wet seasons;

The vertical climate changes greatly and there are many climate types, which is conducive to the comprehensive development of agriculture, forestry and animal husbandry; There are many kinds of meteorological disasters with high frequency and wide range, mainly drought, and heavy rain, flood and low temperature often occur.

1. Subtropical humid climate zone of Sichuan Basin, namely Sichuan Basin and surrounding mountainous areas. This area is warm and humid all the year round, with an annual average temperature of 16 ~ 18℃, a daily temperature of ≥ 10℃ lasting for 240 ~ 280 days, a cumulative temperature of 4,000 ~ 6,000℃, a small daily temperature difference, a large annual temperature difference, warm in winter and hot in summer, and a frost-free period of 230 ~ 340.

There are more clouds and less sunny days in the basin. The sunshine time in 20 13 years is short, only 1000 ~ 1400 hours, which is 600 ~ 800 hours less than that in the lower reaches of the Yangtze River basin at the same latitude. Abundant rainfall, annual precipitation 1000 ~ 1200mm.

2. Subtropical and semi-humid climate zone in the mountainous area of western Sichuan. In 20 13, the temperature in this area is relatively high, and the annual average temperature is 12 ~ 20℃. Annual range is small and the diurnal range is large. It is cold in the morning and warm in the afternoon. The four seasons are not obvious, and the dry and wet seasons are distinct. There is little precipitation. There are seven dry months in 20 13, with annual precipitation of 900 ~ 1200mm, and 90% of them are concentrated in May ~ 10.

There are few clouds, many sunny days and long sunshine hours, and the sunshine hours in the whole year are mostly 2000 ~ 2600 hours. Typical dry-hot valley climate is formed in the valley area affected by foehn, and obvious three-dimensional climate is formed in the mountain area.

3. Alpine climate zone in northwest Sichuan. The altitude difference in this area is great, and the three-dimensional climate change is obvious. Subtropical zone, warm temperate zone, middle temperate zone, cold temperate zone, sub-cold zone and permafrost zone appear in turn from the valley to the ridge.

Generally speaking, the climate is dominated by cold temperate zone, with dry and warm valleys, wet and cold mountains, cool Leng Xia in winter and insufficient water and heat. The annual average temperature is 4 ~ 12℃, the annual precipitation is 500 ~ 900 mm, the weather is clear and the annual sunshine 1600 ~ 2600 hours.

Baidu encyclopedia-Sichuan

Baidu Encyclopedia-Late Rain Phenomenon