Is the three "temperatures" of the ground temperature, local air temperature and forecast temperature?

Recently, some netizens posted a video

Handheld electronic thermometer

On the streets of Wuxi City, Jiangsu Province

Measure the air temperature of 53 ℃

The surface temperature is as high as 63.2 ℃

At this time, the mobile app is displayed

The real -time temperature of Wuxi weather forecast is 40 ℃

The temperature, surface temperature and surface temperature and surface temperature

The temperature gap between the forecast is so large

That weather forecast

Where is the temperature report?

Today, Xiangxiang takes you to reveal the secret!

Temperature measurement is standard

First of all, the air temperature definition is defined. The World Meteorological Organization (WMO) defines the air temperature, as the temperature, and defines "the temperature shown in the thermometer in the air in the air to prevent the solar radiation." It can be seen that the basis for measuring the temperature of the meteorological department is the standard stipulated by the World Meteorological Organization, that is, the air temperature in the shutter at a height of 1.5 meters from the ground.

Blind box photography: Jian Jufang

So, why does the World Meteorological Organization choose a 1.5 -meter -high shutter to test the temperature?

The first is to use the louver to prevent the sun from directly radiating the instrument and the reflex radiation of the ground to the instrument to protect the instrument from the effects of solar radiation, strong wind, rain, snow, etc. Sensing changes in the temperature and humidity of the outside world.

Secondly, the temperature observation record must be representative, accuracy, and comparative. The shutters must be set in places where the average meteorological conditions can be reflected in the observation point. Meteorological detection information is not disturbed by the environment.

According to experts, the temperature measured by the meteorological department under standard observation conditions are different from people's actual temperature measured outdoors, mainly due to the different measurement environment. In addition, the measured instruments are also different. The meteorological department uses a platinum resistor temperature sensor to measure the air temperature, and requires a platinum resistor temperature sensor to resume 0.1 ° C, and the measurement error is within 0.2 ° C.

In fact, not only does my country's meteorological department observe the temperature in accordance with the standards formulated by WMO, the temperature measurement of all countries and regions around the world must be measured. The purpose is to make the temperature and comparative nature of the world from all over the world. If there is no uniform temperature observation standard, and different countries and different countries are measured in accordance with different standards, then global temperature data is not uniform, how can the global warming observation basis be credible? City hot island effect and sample temperature

The video released by the netizen shows that the high -rise building around the shooting point is clearly higher than the temperature data released by the weather department.

Experts explained that after the solar thermal energy radiation reaches the ground, part of them are reflected, and part of them are absorbed by the ground to heat the ground; then the ground will pass the heat to the air through radiation to heat the air. It is precisely for this reason that during the day when the weather is fine, the surface temperature is generally higher than the temperature measured by the shutters.

Due to comprehensive factors such as high degree of hardening, low green plants, factory heat emissions, motor vehicle heat emissions, poor air liquidity in urban areas, high -rise urban center region heat gathering or cooling attributes are very different from the suburbs, and often the more The higher the temperature of the medium and large cities, the "urban heat island effect" in the urban ecological environment.

For example, in the same place, the same time period, and the same weather environment, the temperature measured at 1.5 meters on the asphalt road is different from the observation station's lunch box. For example, under the strong direct sunlight, the temperature may even be about 4 ℃ higher than the observation temperature of the shutter box on the height of 1.5 meters above the urban cement road and asphalt road. Similarly, the temperature measured by grass, water, ice, etc. are different.

In addition, at the same environment, the temperature of different people feels different, that is, the temperature temperature. In addition to the temperature affected by the temperature, the temperature of the body is also affected by factors such as air humidity, wind, solar radiation, dress color, and even mood.

The temperature in the weather forecast

how did it get here?

According to experts, in the meteorological forecast, a representative site will choose a representative site to predict the temperature of the area. Taking Beijing as an example, the temperature of the alphabetic louver box in the southern suburbs is usually the basis. Even in the same city, the temperature between various areas is different, and different areas such as Haidian, Chaoyang, and Shunyi are different at the same time.

Therefore, the temperature forecast of the Meteorological Observatory in Beijing is a representative site in this area, while following the basic principle of "air temperature in a clue box at a height of 1.5 meters from the ground" stipulated in the World Meteorological Organization.

In addition, in addition to solar radiation, ground reflection, and different under -pads, the main factors that affect the temperature changes in a region include temperature flat flow, vertical exercise and non -heat factors. Temperature flat flow mainly refers to the cold air that can reduce the temperature and the warm air to increase the temperature; the vertical motion refers to the temperature when the sinking movement will be increased, and the rising exercise will cool down; , Driven Dives, etc.

Therefore, when the meteorological department predicts the temperature, it is necessary to consider the comprehensive effects of the above factors to make judgments.

Do you know now?

The China Meteorological Administration's Xuanke Center (China Meteorological News) produced by
Author: Jian Jufang Antao

Expert Consultant: Zhang Xin, senior engineer of the China Meteorological Bureau Meteorological Exploration Center Senior Engineer Zhang Xin

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