Hi,
Changes on the sun can affect the environment around Earth and other places in the solar system, affecting spacecraft, communications, power systems and other technologies. The study of these variations and their effects is called space weather.

“Solar storms” are space weather disturbances. Scientists have more specific words for the disturbances, things like coronal mass ejections (CMEs) and flares. You can read more about them here:
http://multiverse.ssl.ber...dnesday/TheActiveSun

Terry

Terry mentioned some of the types of solar space weather, but other types of space weather are geomagnetic storms, substorms, and the aurora.

Substorms are a very common type of space weather that occurs during moderately active times in the space environment surrounding the Earth. The solar wind stretches out Earth's magnetic field into a long tail, called the magnetotail, on the night side of the Earth. Changes in the solar wind speed and magnetic field direction can cause a build up of magnetic energy in the magnetotail. When this magnetic energy is released during a type of space weather called a substorm, it generates huge electrical currents in Earth's magnetic field and beautiful auroral displays can be seen in the Earth's polar regions.

Geomagnetic storms are the type of space weather that occurs during very active times in the space environment surrounding the Earth. Solar storms, such as the coronal mass ejections (CMEs) that Terry mentioned, as well as extremely high-speed solar wind from coronal holes, can drive geomagnetic storms. When a CME shock arrives that the Earth, it can push the boundary between the Earth's magnetic field and the solar wind (the magnetopause) in towards the Earth on the dayside. Scientists call this a sudden storm commencement or a sudden compression, and it can be observed by magnetometers on the Earth's surface. If a really big shock hits the Earth, the magnetopause can be pushed into geosynchronous orbit, which is where communications and weather satellites are located. In addition, geomagnetic storms can cause the build-up of high energy protons and electrons in the Earth's radiation belts and ring current, which are also situated near geosynchronous orbit. These high energy protons and electrons can cause issues with the satellites near geosynchronous orbit. Lots of substorms can also occur during a geomagnetic storm, hence the name "substorm." All of the changes in the Earth's magnetic field during geomagnetic storms can generate huge electrical currents which affect electrical power systems on Earth. In 1989, a big geomagnetic storm caused a famous electrical blackout when the storm currents damaged the power grid.