The Richardson number (Ri) is named after Lewis Fry Richardson (1881–1953). It is the dimensionless number that expresses the ratio of the buoyancy term to the flow shear term: = = / (/) where is gravity, is density, is a representative flow speed, and is depth.. The Richardson number, or one of several variants, is of practical importance in weather forecasting and in …

Anna Clare Richardson (born 27 September 1970) is an English television presenter, writer and journalist. She has presented various television shows for Channel 4, including Supersize vs Superskinny (2008–2009), The Sex Education Show (2008–2011), Secret Eaters (2012–2014), Supershoppers (2016–2019), Naked Attraction (2016–present) and Changing Rooms …