A five‐year climatology of elevated inversions at Hemsby (UK)

Temperature inversions up to the 500‐mbar level are studied in 50‐mbar depth layers over Hemsby, in eastern England. The inversions are characterized by vertical gradients of temperature, potential temperature, dew point temperature, and depth. An inversion index, which is the product of potential temperature gradient and frequency of occurrence, is used. The zone of maximum activity for elevated inversions is 950–800 mbar, resulting from subsidence within anticyclones. A theoretical explanation of the processes is given. Inversion characteristics are essentially similar for day and night, except in the 1000–950‐mbar layer, where daytime frequency is greater. It is suggested that turbulence‐capping inversions and/or sea‐breeze effects may be the reason. The implications of elevated inversions for air pollution dispersion are discussed.