SDO solar image - 94 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
satellite
radio propagation
Today's Space Weather
Friday 03 July
last updated 02/2331 UT
Solar flare activity was low during 2 July UT. Active Region 2376 produced the largest flare of the day, a C3.7 event peaking at 15:30 UT. Solar flare activity is expected to remain low during the next 48 hours. The halo Coronal Mass Ejection (CME) observed expanding from the western limb during 1 Jul was a far side event. It may unsettle the geomagnetic field on 5 July. A large coronal hole is traversing the central meridian of the solar disk. Solar wind speeds are moderate at about 350 km/s but are expected to increase later today. Geomagnetic conditions are expected to be quiet to unsettled during the next 3 days. Conditions for HF radio wave propagation were mildly depressed throughout the Australian region during 2 July. The conditions are expected to be mildly depressed again today.
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
Aurora Australis as seen from the International Space Station, with the port wing of space shuttle Atlantis, and segment of a boom sensor system attached to the shuttle's robotic arm.
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