Past week’s Weather
UK A split week for the
Falklands A dry but cloudy start to the week with rain by the end of the week. Generally sunny over the weekend. A fairly windy week though.
Ascension A rather cloudy week this week I think you’ll agree, although some sunny spells arriving in time for the weekend.
St. Helena A fairly cloudy week although some good sunny spells at times especially in the afternoons. Breezy through much of the week but mainly dry.
We’ve all (or mostly all) heard about Solar Flares more and more in the news recently as they disrupt radio signals, but what are they?
Solar flares are enormous explosions that occur on the surface of the Sun. They result in the emission of colossal mounts of energy. In addition to this, the larger solar flares also eject large amounts of material mainly in the form of protons.
Flares erupt in just a few minutes with little warning. When they occur the material is heated to millions of degrees Celsius and it leaves the surface of the Sun in a huge arch, returning some time later. The flares normally occur near sunspots, often along the dividing line between them where there are oppositely directed magnetic forces.
It is the magnetic fields appear to be responsible for the solar flares. When the magnetic field between the sunspots becomes twisted and sheared the magnetic field lines may cross and reconnect with enormous explosive energy. When this occurs an eruption of gases takes place through the solar surface, and it extends several tens of thousands of miles out from the surface of the Sun and follow the magnetic lines of force to form a solar flare.
Flares generally only last for about an hour, after which the surface of the Sun returns to normal although some Post Flare Loops remain for some time afterwards. The flares affect radio propagation and radio communications on Earth and the effects may be noticed for some time afterwards.
So now we not only need to forecast when we might see the sun through the layers of cloud but also how much energy it may be emitting?! I’ll be in the bar…
Compiled by: Lotta Hottaire
Crown Copyright 2011
Met Office Ascension Island base