SDO solar image - 335 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
satellite
radio propagation
Today's Space Weather
Monday 06 July
last updated 05/2333 UT
Solar flare activity was very low during 5 Jul UT, and it is expected to be low today, 6 Jul. The arrival of fast solar wind during the second half of 4 Jul caused a brief NOAA class G2 geomagnetic storm during early 5 Jul. The Kp index of planetary magnetic activity reached 6 during the 00-03 UT and the Australian region Dst disturbance storm time index briefly decreased to -115 nT during 04 UT on 5 Jul. The geomagnetic storm is well into the recovery phase: conditions are expected to be unsettled during 6 Jul and quiet during 7 Jul. Conditions for HF radio wave propagation were enhanced during 5 Jul relative to the previous week, a positive effect of the G2 geomagnetic storm. Similar conditions are expected today, 6 Jul, though trending back toward mildly depressed, especially at low latitude stations.
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.
What's Inside