Circle of light around the moon or sun created by light refracted by ice crystals in cold cirrus clouds (4) Unit of length equal to nine inches, based on the distance between the tips of the thumb and little finger (4) Pain-relieving drug such as codeine, ibuprofen or paracetamol (9) Irregular fluctuations which tend to obscure electrical signals or radio reception, also called static (5) Triatomic molecule which is an allotrope of oxygen and an air pollutant (5)