Space weather is a sub-field of space physics which observes and investigates conditions and phenomena in the Solar System with an emphasis on the immediate space around the Earth and conditions/phenomena with the greatest impact on Earth. While the effects of space weather such as the auras for example have been known for a very long time, they were not understood until the emergence of modern astronomy. But despite the enormous progress in the understanding of space weather, many conditions and phenomena haven’t been fully explained yet.
Space Weather Phenomena at a Glance
Astronomical objects within the Solar System are dramatically influenced by various space weather phenomena which occur at varying times and varying intensities. Some of the most dramatic ones include:
Solar wind. This term refers to a stream of particles that escape from the Sun’s upper atmosphere at varying speeds which can reach as much as 1 million mph. The speed, density and distribution depend greatly on solar longitude and time - especially the Solar cycles.
Coronal mass ejection. Also known under the acronym CME, the coronal mass ejection refers to a huge burst of plasma from the solar corona (outer atmosphere) with potentially massive implications for the Earth. Besides intense auroras in the northern and southern hemispheres, the CME can also result in geomagnetic storms and various disturbances of spacecraft and terrestrial electronics including electrical transmission.
Geomagnetic storm. The expression describes a disturbance of the Earth’s magnetosphere which is caused by strong solar wind shock waves, usually after a major coronal mass ejection. The largest geomagnetic storm every recorded took place in 1921. In addition to disrupting telegraph service it also caused a serious damage to electric power grids around the world.
There are also many other space weather phenomena with many posing a potentially very serious threat to Earth. Read on how space weather can directly or indirectly affect life on Earth and human activities in the space.
Effects of Space Weather
As mentioned above, some space weather phenomena such as geomagnetic storms can cause major disturbances on Earth by interfering with various technologies, especially electronics and telecommunications but they can also cause problems with electrical transmission. However, phenomena such as solar wind and coronal mass ejections for instance, are much more likely to cause damage to spacecraft electronics and seriously jeopardise humans in space.
Although being distinct from terrestrial weather, space weather can also affect the weather on Earth not only by causing auroras but by influencing other weather occurrences as well. But it is also important to mention that the link between space and terrestrial weather is not exactly clear yet.