When is World Meteorological Day?

March 23rd is World Meteorological Day. 1947 September to 10/0 October, the International Meteorological Organization (IMO) held a meeting of meteorological directors of 45 countries in Washington, USA, decided to establish the World Meteorological Organization and adopted the Convention of the World Meteorological Organization. According to the Convention, the 30th day after the 30th ratification was submitted, on February 2 1, 1950, the 30th ratification was submitted by the Iraqi government, and on March 23, the World Meteorological Organization Convention came into effect, marking the formal birth of the World Meteorological Organization. To commemorate this special day, the World Meteorological Organization designated March 23rd, when the Convention came into effect, as World Meteorological Day.

March 23rd is World Meteorological Day, and the Meteorological Bureau of Donghai County, Jiangsu Province held an open day. Many primary and middle school students walked into the bureau and listened to meteorologists explain meteorological knowledge on the spot.

Meteorological common sense

1. Weather chart and satellite cloud picture: charts used to analyze atmospheric physical conditions and characteristics are collectively called weather charts. There are mainly two kinds of ground weather maps and high-altitude weather maps. Satellite cloud picture is a picture of clouds sent back by meteorological satellites, which can show a wide range of cloud conditions and is one of the reference bases for weather forecast.

2. Weather forecast: "Today's daytime" means 12h from 8:00 am to 2O: 00 pm; "Tonight" means 12h from 2O:00 to 8:00 the next morning. "Cloudy" means that the amount of clouds accounts for 40% ~ 70%; "Yin" means that the cloud cover accounts for 80% ~100%; "Clear" means that the cloud cover accounts for 10% ~ 30%.

Legend of weather symbols

4. Rainfall intensity: Rainfall intensity refers to the rainfall in a unit time period, and the unit is millimeters per minute or millimeters per hour.

5. Rainfall: The accumulated depth of rainwater on the horizontal ground in a certain period of time, expressed in millimeters.

6. El Ni? o: El Ni? o is divided into El Ni? o phenomenon and El Ni? o event. El Nino is a climatic phenomenon, which occurs in the tropical Pacific Ocean, where the sea surface temperature is unusually warm. Large-scale warming of tropical Pacific will cause global climate change. When the average index of warm sea surface temperature exceeds 0.5℃ and lasts for at least 6 months, it is defined as an El Ni? o event.

7. Rainfall grade: Precipitation is divided into six intensity grades: light rain, moderate rain, heavy rain, heavy rain, heavy rain and torrential rain.

8. Rainstorm warning signal: The rainstorm warning signal is divided into four levels (IV, III, II and I), and the warning signal is blue, yellow, orange and red in turn. They stand for average, heavy, serious and particularly serious.