Space weather is defined as the collection of physical processes, beginning at the Sun and ultimately affecting human activities on Earth and in space. The weather we feel at the surface is influenced by the minute changes in the sun’s activity. The Sun emits photons in different wavelengths that travel throughout space and interact with our atmosphere. Most of the energy the Sun emits is in the form of visible light between 400 and 800 nano-meters (nm). This output from the Sun is relatively constant, fluctuating about 0.1% in a solar cycle. The Sun also emits ultraviolet light (UV) between 120 and 400 nm that gets absorbed by the ozone layer in Earth’s stratosphere. There is more variability in the Sun’s output in UV wavelengths (up to 15%) than any other wavelength. Finally, the Sun produces infrared light (around 800 to 1,000 nm) which has little change in output.
The Earth is in balance with the energy the Sun produces, but there are events that occur in space that can throw off the unity between them.
Solar Radiation Storms (SRS) are massive magnetic eruptions from the Sun, often causing solar flares, which send charged particles throughout space at around one-third the speed of light. This can reach Earth in about 30 minutes. These storms vary in intensity, with stronger storms being less frequent. If a massive SRS were to strike Earth, protons would interrupt electrical equipment, including satellites, and can even damage DNA. The latest strong SRS to strike Earth was the solar storm of 1859, which caused auroras to occur as far south as the Caribbean.
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©2017 Meteorologist David Tedesco