What are the characteristics of temperature change?

1. Temperature: namely air temperature, which is a physical quantity indicating the air temperature. The heat in the air mainly comes from solar radiation. When the sun reaches the surface, part of it is reflected, while the other part is absorbed, which makes the surface warm. Then the ground transfers heat to the air through radiation, conduction and convection. This is the main source of temperature. The part of solar radiation directly absorbed by the atmosphere has little effect on heating air, and can only increase the temperature by 0.0 15 ~ 0.02℃.

2. Daily temperature range: the difference between the highest temperature and the lowest temperature in a day.

The daily temperature range is related to latitude, season, topography, altitude, weather and vegetation.

3. Temperature annual range: the difference between the highest monthly average temperature and the lowest monthly average temperature in a year.

The temperature annual range is related to latitude, distance from the sea, altitude, cloud cover and rainfall.

Isothermal zone, comfort zone and critical temperature

There are two main forms of body temperature regulation: heat dissipation regulation and heat production regulation.

Heat dissipation regulation, also known as physical regulation, means that in hot or cold environment, the body relies on the relaxation and contraction of skin blood vessels, the increase and decrease of skin blood flow and the change of skin temperature to increase or decrease heat dissipation by strengthening or weakening sweat glands and breathing activities, finding more comfortable places and changing posture. So as to maintain normal body temperature.

Thermogenic regulation, also known as chemical regulation, means that under severe cold and heat stress, the body must reduce or increase thermogenesis by reducing or increasing the oxidation of nutrients in the body to maintain normal body temperature.

Isothermal zone: refers to the ambient temperature at which warm-blooded animals rely on body regulation to maintain normal body temperature.

Critical temperature: refers to the lower limit temperature of isothermal zone.

Overtemperature: refers to the upper limit critical temperature of isothermal zone.

Comfort zone: refers to a certain temperature zone in the isocratic zone. In this temperature zone, the body can produce heat and dissipate heat equally without any way of body temperature regulation, and the body is more comfortable, and the heat production of its metabolic intensity is at the lowest physiological level.

Temperature and somatosensory temperature forecast

With the continuous improvement of people's living standards, people pursue a high-quality lifestyle. For example, weekends, holidays, family trips or fitness. These activities have become an important way of life for people. Therefore, it is necessary to pay attention to the weather forecast. But sometimes, although the weather forecast, especially the temperature forecast, of the meteorological station has reached a fairly accurate level, many people still feel that the predicted temperature is inconsistent with their actual feeling of hot and cold, thus complaining that the forecast is not accurate; Sometimes it is even thought that the meteorological station consciously reported the high temperature in summer or the low temperature in winter. Why is this happening?

In fact, there is a misunderstanding. As we all know, the temperature is the only sign of cold and warm nature. However, it is not the only sign that the human body is cold and warm. Therefore, under the same temperature conditions, people will have different cold and warm feelings due to the constant changes of humidity and wind speed.

Under normal circumstances, human skin temperature is slightly lower than body temperature, about 32℃. Theoretically, when the temperature is higher than 32℃, the human body should feel hot, but this is not the case. For example, in an environment with a temperature of 35℃, if the relative humidity of air is about 40% ~ 55%; When the average wind speed is above 3m/s, people will not feel very hot; But in the same temperature environment, if the humidity increases above 80% and the wind speed is very small, people will feel sultry and even suffer from heatstroke. Similarly, in the low temperature environment, different humidity and wind speed will also bring different cold feelings to people. In addition, different colors of coats, clouds in the sky and other factors will also affect people's feelings about the actual environmental temperature. It can be seen that people's feeling of environmental temperature is the result of the comprehensive influence of many factors.