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<p>into the sky are <a href="page.php?w=Refraction">refracted</a> back to Earth by layers of charged particles (<a href="page.php?w=ion">ion</a>s) in the <a href="page.php?w=ionosphere">ionosphere</a>, the <a href="page.php?w=E_layer">E</a> and <a href="page.php?w=F_layer">F layer</a>s. 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,</p><p>
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