What is the modern weather forecast?

The development of modern science and technology provides advanced equipment for modern weather forecasting. Advanced meteorological satellites, radar network all over the country, and powerful supercomputer system that can calculate complex weather models have greatly improved the accuracy of weather forecast.

In the late 1970s, Japan used meteorological satellites, which not only collected all kinds of meteorological data from high altitude, but also greatly improved the work efficiency and forecast accuracy of meteorological departments. Therefore, the weather forecast of TV stations has become vivid and vivid: the typhoon eye and its surrounding clouds, the range, direction and speed of activities, and the movement of rain and snow areas can be seen at a glance.

The territory of the United States is very vast, and its weather forecast system is even bigger. In order to know the weather around the world, four meteorological satellites provide meteorological information. There are two TV and infrared observation satellites whose orbits pass through the north and south poles of the earth. Television photography on satellite spreads the shape and moving direction of cloud, and infrared photography shows the height of cloud and the moisture contained in water vapor. The other two synchronous meteorological satellites are located in the air-to-ground geostationary orbit on the equator and take pictures of the earth at fixed points.

In addition, there are hundreds of small data collection devices on airplanes, ships, buoys or helium-filled balloons. The sensors of these acquisition devices will automatically measure the wind speed, temperature, humidity and air pressure in various places. There are more than 70 radar stations in China to track thunderstorms and hurricanes.

Doppler radar system is an advanced meteorological detection equipment. This system emits light beams in all directions with a radius of 200 kilometers around, and measures the wind speed and direction on various horizontal planes parallel to the ground by detecting the movements of water drops, grass seeds, dust and insects in the atmosphere. Its weather forecast is very specific: where, when and how many millimeters of rain will there be. If there is a sudden change of air flow in some areas within a few minutes, the Doppler radar system can also make quite accurate predictions.

Another kind of laser Doppler radar "LEDA" is a new equipment for monitoring ground meteorological conditions. It is installed on a polar orbiting satellite and can measure wind speed twice a day. If there are two satellites carrying Lida, we can monitor the atmosphere of the whole earth. After adopting "Lida" system, the medium-range weather forecast of 7 ~ 10 days can be as accurate as the current 24-hour forecast. Airlines can also benefit from Lida, because the pilot had a detailed airflow map at that time, and he could use the fast wind to avoid the oncoming wind, which not only saved time and fuel, but also ensured the safety and reliability of the flight.

In recent years, a major breakthrough in meteorological engineering is the application of wind direction simulation system. The simulation system uses a radar beam to continuously measure the wind direction and wind speed in the range of 1.6 ~ 14.4 km, and takes one wind speed and wind direction data every 100 m in the vertical direction, and can collect hundreds of data every square kilometer. It is displayed on the monitor screen: some colored arrows, with color, length and direction, represent height, wind speed and wind direction respectively. The computer quickly compared the data input a few hours ago with the satellite data, and showed the movement of local small airflow on the screen, which improved the accuracy of forecasting local microclimate to an unprecedented level.

The computer weather model located in Maryland is based on meteorological data transmitted all over the world, including wind direction, wind speed, temperature, humidity, air pressure and so on. The high-altitude meteorological instruments of 650 meteorological balloons in China collect meteorological data, all of which are sent to the working satellites in geostationary orbit, and then sent back from space to the satellite ground receiving station, and then sent from the ground station to the meteorological center. After a few minutes, the information recorded by buoys or airborne acquisition devices in various places will be collected in the center, and many computers will quickly process all kinds of data, thus forming a mathematical description of the weather at that time. The meteorological center in the United States sends 2000 such reports to major forecasting centers every day, and then transmits them to local institutions through them. Local meteorological stations publish local weather forecasts in combination with the latest satellite images, measured data on the ground and their own experience. This prediction is quite accurate.