SDO solar image - 171 angstroms - Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
satellite
radio propagation
Today's Space Weather
Tuesday 23 August
last updated 22/2323 UT
Solar activity has been Very Low over the last 24 hours. The effect of a high speed solar wind stream from a negative polarity coronal hole may strengthen the solar wind stream from 24 August. Solar activity is expected to stay at Very Low levels for the next three days with some possibility of isolated C-class event. Geomagnetic activity stayed at Quiet levels today (22 August, UT day). Nearly similar conditions may be expected for 23 August. Geomagnetic activity may rise to Active levels on 24 and 25 August due to a coronal hole effect. Mild to Moderate MUF depressions were observed in the equatorial regions during the UT day, 22 August. MUFs were near predicted monthly values for mid and high latitude locations. Nearly similar HF conditions are likely to continue on 23 August. Further depressions in MUFs and degradations in HF conditions may be observed on 24 and 25 August due to 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
Type II solar radio spectrograph event 17 Dec 2014
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