A new concept of space weather
The traditional physical definition of "weather" is: the atmospheric state comprehensively displayed by meteorological elements such as wind, clouds, precipitation, temperature, and air pressure in an instant or within a relatively short period of time. Weather in daily terms refers to the neutral atmospheric physical images and physical states that occur in the troposphere and affect human life and production, such as cloudy, sunny, rain, snow, cold, warm, dry, wet, etc.
Space weather is a concept of changes in the near-Earth space environment. It is distinct from weather within a planet's atmosphere and involves phenomena such as space plasma, magnetic fields and radiation. Space weather is often closely associated with the near-Earth space magnetosphere, but it also studies changes in interplanetary space. In our solar system, space weather is mainly affected by the wind speed and density of the solar wind, and the interplanetary magnetic field brought by the solar plasma. A variety of physical phenomena are associated with space weather, including geomagnetic storms and substorms, currents in the Van Allen radiation belts, ionospheric disturbances and scintillations, auroras and currents induced by magnetic field changes at the Earth's surface.
Coronal mass ejections and related shock waves are also important drivers of space weather because they can compress the magnetosphere and trigger geomagnetic storms. High-energy particles from the sun, coronal mass ejections or accelerated by solar flares, are also important drivers of space weather, as they can damage spacecraft electronics and threaten the lives of astronauts. Space weather has a profound impact on these fields of space exploration and development. Changes in the geomagnetic field can cause changes in atmospheric density, causing the altitude of low-Earth orbit spacecraft to rapidly decrease. Geomagnetic storms caused by solar activity can blind sensors on spacecraft and interfere with onboard electronics. Understanding the space environment is critical for the design of protective systems for man-made spacecraft. Magnetic storms will also increase the amount of radiation for flight attendants flying at high altitudes.
Space weather refers to changes in the state of the space environment in near-Earth space or from the solar atmosphere to the earth's atmosphere. Different from the concept of weather in the Earth's planetary atmosphere (troposphere and stratosphere), space weather describes changes in background plasma, magnetic field, radiation, etc. in space. Most space weather events are driven by energy carried by the solar wind originating from the Sun's near surface and solar atmosphere (chromosphere and heliosphere). Space weather sometimes also refers to changes in environmental conditions in interplanetary space (and rarely interstellar space).
Space weather has two focuses: scientific research and application. The term space weather did not come into use until the 1990s, and before that time, space weather activity in the current sense was considered part of physical or upper atmospheric physics and space exploration.