FORECAST SOL: Normal green MAG: Moderate yellow ION: Moderate yellow
SDO solar image - 4500 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
radio propagation
Today's Space Weather
Saturday 22 October
last updated 21/2328 UT
Solar activity was very low over the last 24 hours. Solar activity is expected to stay at very low levels for the next three days (22, 23 and 24 October) with some chance of C-class activity. The effect of a positive polarity coronal hole is expected to strengthen the solar wind stream from late on 22 October for the next few days. Geomagnetic activity stayed mostly at Quiet levels on most locations today (UT day 21 October). Geomagnetic activity is expected to be mostly at Quiet levels during the first half of 22 October. The effect of a coronal hole may raise the geomagnetic activity to unsettled and possibly active levels late on 22 October and up to minor storm levels on 23 and 24 October. Mainly due to low levels of ionising radiation, minor to moderate MUF depressions were observed today (UT day 21 October). Nearly similar conditions may be expected during most parts of UT day 22 October. Minor to significant MUF depressions may be expected on 23 and 24 October due to very low levels of ionising radiation and expected rise in geomagnetic activity levels on these days.
What is Space Weather ?

Space weather refers to changes in the space environment, particularly the region between the Earth and Sun. The "solar wind" from the Sun stream past the Earth and is mostly deflected by the Earth's magnetic field, but variations in the solar wind cause changes in the Earth's magnetic field.

solar prominence

Occasionally, a huge release of magnetic energy, called a solar flare, occurs on the Sun. Flares can produce large quantities of x-rays which affect the Earth's atmosphere. They can also accelerate atomic particles (mostly protons) to very high speeds (a substantial fraction of the speed of light!). These high energy particles are dangerous to man and can reach the stratosphere where jetliners fly.

Most aspects of space weather affect us to some extent. The more our society becomes dependent on technology and the more we utilise space, the more we are affected by space weather. Some aspects of space weather are benevolent, and allow activities not otherwise possible such as long range radio communications. Some aspects are benign but fascinating such as the Aurora, and some are malevolent. Like terrestrial weather, it sometimes depends on the situation and the event.

The image below is an artists impression of the solar wind interacting with the Earth's magnetic field.

Solar wind
Combined image of active region 1520 shortly before it unleashed an X-class flare. The image is made up of light in the 171 Angstrom wavelength, and a magnetogram.
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