GONG H-Alpha solar image
satellite
radio propagation
Today's Space Weather
Thursday 07 May
last updated 06/2342 UT
Solar flare activity was moderate during 6 May UT. Active Region 2339 produced the largest flare of the day, a M1.9 event peaking at 11:49 UT. AR 2335 was quieter than yesterday but still has the potential to produce significant flares. H alpha solar telescope observations recorded the disappearance of a large, unstable solar prominence in the geoeffective sweet spot west of the solar meridian during 15 UT on 6 May. An update will follow if the SOHO coronograms show an Earthward directed CME. A solar wind shock arrived at Earth at 00:50 UT due to the arrival of the CME launched on 2 May. The solar wind speed increased to more than 500 km/s and and a minor geomagnetic storm (G1) occurred last night. Geomagnetic conditions are expected to recover toward quiet levels during 7 May. Conditions for HF radio propagation are expected to be near predicted monthly values during 7 May.
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
Closeup of a sunspot showing convection cells.
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