Traditional Culture Encyclopedia - Weather forecast - Relationship between air humidity and temperature

Relationship between air humidity and temperature

Old and immortal; In meteorology, the physical quantity representing the degree of air heat and cold is called temperature, which is referred to as temperature for short. The international standard unit for temperature measurement is Celsius (℃). The temperature mentioned in the open weather forecast was measured with a thermometer in a louver box 1.5 meters above the ground in an observation scene with turf. The thermometer is representative because it keeps good ventilation and avoids direct sunlight. In the hot summer afternoon, the temperature in small environments such as cement pavements and exposed balconies with heavy traffic is much higher than that in shutters-which is why some people think that the actual temperature does not match the temperature broadcast by the meteorological station.

Air humidity is a sign indicating the water vapor content in the air or atmospheric humidity. Its size can be expressed by water vapor pressure, absolute humidity, relative humidity and dew point temperature. Relative humidity is most commonly used in public weather forecast. Relative humidity is the percentage of the actual water vapor pressure in the air and the saturated water vapor pressure at the same temperature. It is only a relative number, indicating the degree of air humidity from saturation.

Air pressure is atmospheric pressure. Air has weight, and air pressure refers to the force exerted by the atmosphere per unit area. In meteorology, hectopascals are often used as the unit of pressure measurement. Air pressure is variable, and its level is related to the density, temperature and humidity of air. The higher the air density, the lower the temperature and humidity, and the greater the air pressure, and vice versa. These different pressure distributions constitute the pressure field, and analyzing the pressure field and its changes with time is an important basis for making weather forecast.