Medium frequency travel longer distances via skywave propagation, in which radio waves radiated at an angle into the sky are reflected (actually refracted) back to Earth by layers of charged particles (ions) in the ionosphere, the E and F layers. However at certain times the D layer (at a lower altitude than the refractive E and F layers) can be electronically noisy and absorb MF radio waves, interfering with skywave propagation. This happens when the ionosphere is heavily ionised, such as during the day, in summer and especially at times of high solar activity, At night, especially in winter months and at
Night Waves Night Waves Night Waves was a radio programme broadcast on BBC Radio 3. The BBC described it as "Radio 3's flagship arts and ideas programme". "The Guardian" said in May 2010 "...the king of radio arts programmes is undoubtedly "Night Waves", a programme so clever that it regularly makes me stand still and listen, usually halfway to the dishwasher with a plate in my hand...It's the desire to untangle arguments, to lift up their corners and see what lurks there. There's a gleeful range of references too...and a relish for intelligent debate." It was broadcast every Monday to Thursday evening,