What do weather phenomena include?

Combined with other factors used to predict meteorological changes, weather phenomena include visibility (within a few miles or kilometers), cloud shape and height, and the proportion of gathering in the sky. The previous wind, the rainfall in a certain period of time. Finally, it includes the thickness of snowfall and the amount of water contained in the snow.

The Global Meteorological Observatory conducts ground observation at least once an hour and sends the observation results to the meteorological department of the country where it is located.

Most of these readings were processed and made public within a few minutes. This is due to international cooperation and the Internet. In addition, volunteer observers also control nearly 10,000 weather stations, and each person makes one or two observations every day. The observation report, together with international data, laid the foundation for climate observation.

In the past few years, many countries, including Japan and the United States, have fully or mostly automated ground observation websites. In this way, observers only check and maintain these websites. These websites are equipped with the most advanced electronic equipment, and the observation results can often be transmitted once in 10 ~ 15 minutes.

Before the invention of weather balloons, people's observation of atmospheric motion was only related to the ground. Since the19th century, balloon experiments have been used to obtain the atmospheric motion above the ground, and these heights of airflow play a key role in the weather movement and change.

The radio came out in the 1920s. It was not until the advent of radiosondes that stations with weather balloons changed people's views on the upper atmosphere. The most typical example is that radiosonde measures air pressure through a small barometer and measures the influence of temperature and humidity on electrical conductivity. With the rise of radiosonde, it sends back reports by radio, and measures wind speed and direction according to the changes of radiosonde in a certain area. About an hour later, a special radiosonde rose 15 miles (24 kilometers). The balloon inflated and finally exploded. The instrument package has completed its task and landed on the ground with a micro parachute.

In the 1940s, radiosondes spread information to the whole world every day. Meteorologists will soon study high-altitude jets and other features. At present, 1000 radiosondes are launched every day in the world, most of which are in the northern hemisphere.

Radar is the best tracker, which can track the wind during a thunderstorm. You can also draw a salty map of the rain and snow area. The first radar was developed and improved during World War II, and later became a civilian radar. Radar sends out electromagnetic signals, usually microwaves, which will turn back when encountering raindrops, hail and snowflakes; By measuring the time required for the signal to return to the radar and how many signals return, scientists can calculate how far the precipitation area is and how much precipitation there is.