What does microclimate mean?

It is called microclimate, which is formed by the influence of underlying surface conditions, and is different from large-scale climate. According to the different types of underlying surface, it can be divided into farmland microclimate, forest microclimate and lake microclimate. Compared with large-scale climate, microclimate has five characteristics:

The range of 1) is small, within 100 meters in the vertical direction, mainly below 2 meters, and it can reach several millimeters to dozens of kilometers in the horizontal direction. Therefore, the observation of conventional weather station network can not reflect the microclimate difference. For microclimate research, it is necessary to set up a microclimate survey with high measuring point density, many observation times and high instrument accuracy.

2) There are great differences. No matter in vertical or horizontal direction, the meteorological elements are very different. For example, in the stratum near the ground, the temperature drop rate in the vertical direction is often 2 ~ 3 orders of magnitude larger than that in the upper layer.

3) change quickly. In the microclimate, the temperature, humidity or wind speed change with time faster than that of the macroclimate, and it is pulsating. Like m.n.

Goelz Mann once measured the maximum temperature change of 7.65438 0℃ in 25 minutes at a height of 5 cm.

4) The diurnal variation is intense, and the closer to the underlying surface, the greater the diurnal variation of temperature, humidity and wind speed. For example, the daily variation of surface temperature can reach 40℃ in summer, but it is only 10℃ at a height of 2 meters.

5) The microclimate law is stable. As long as the physical properties of the underlying surface that forms the microclimate remain unchanged, the microclimate differences will not change. Therefore, we can learn some microclimate characteristics from the short-term investigation.

Because the scope of microclimate influence is the space of human production and life, it is of great practical significance to study microclimate. We can also use microclimate knowledge to serve human beings, for example, planting trees and flowers rationally in cities, greening courtyards and improving the underlying surface conditions of cities, which can improve microclimate conditions in urban residential areas or factory areas and reduce air pollution.