SDO solar image - 335 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
satellite
radio propagation
Today's Space Weather
Thursday 25 August
last updated 24/2321 UT
Solar activity has been very low over the last 24 hours. Solar wind conditions may stay strong on 25 August due to the continued effect of a coronal hole. Solar activity is expected to stay at very low levels for the next three days with some possibility of isolated C-class event. Due to strong solar wind stream from a coronal hole, geomagnetic activity increased to active levels on 24 August. Geomagnetic activity may stay at unsettled levels with the possibility of some active periods on 25 August due to the coronal hole effect. Activity levels may gradually decline to unsettled and then quiet levels on 26 August. Mostly quiet periods can be expected on 27 August. Mild to Moderate MUF depressions were observed in some low and mid latitude regions during the UT day, 24 August. MUFs were near predicted monthly values for most other regions. Mild to moderate depressions in MUFs and degradations in HF conditions may be observed on 25 and possibly 26 August due to expected continued rise in geomagnetic activity levels on these days. Mostly normal HF conditions may be expected on 27 August.
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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