太空天气预报.PPT

太空天氣預報 How do Magnetic Storms Form? All magnetic fields have a direction. The solar wind’s field can point in all sorts of directions: towards Earth, away from Earth, towards the north, towards the south, and even towards the east and west. The actual direction of the field when a mass ejection comes crashing into Earth’s magnetosphere is very important. If it’s directed southward, we have found that disturbances in the solar wind, like CMEs, can penetrate Earth’s protective shield and cause magnetic storms. If the solar wind’s magnetic field has some other direction, like northward, then conditions are mild. The direction of the field acts like an electric switch: northward the switch is off; southward it is turned on. Space Weather: Early Warnings (1) Like meteorologists who check temperatures, winds, and pres sure to predict the weather on Earth, scientists monitor the Sun and our space environment to forecast the weather in space. Using spacecrafts like SOHO, Earth-based telescopes, and old-fashioned hand sketches of the Sun, scientists search the surface of the Sun for signs of flares and CMEs. They monitor the solar wind as it blows toward Earth to see if it is carrying foul weather, and they measure the energy flowing into Earth’s upper atmosphere and the distortion of magnetic fields near the ground. From these bits of information, NOAA’s Space Environment Center forecasts whether our space weather will be mild or wild. Space Weather: Early Warnings (2) Utilizing a fleet of spacecraft, scientists in dozens of countries observe the Sun, the solar wind, the near-Earth space environment, as well as the aurora. Ground-based telescopes, radar and supercomputers are used alongside these spacecraft to provide a picture of current and future space weather conditions. We are learning what it means to truly live within the atmosphere of the Sun. 太空天氣預報中心與預報內容 Space weather forecast (1) Space weather forecasts and alerts are issued by NOAAs Space Weather