EXISTENCE OF CONSTANT-FLUX LAYER ABOVE THE URBAN AREA

Abstract

Using the data of the continuous field observation at residential site in Tokyo from March 2001, following results are obtained; 1) The existence of constant-flux layers for momentum, sensible-heat and latent-heat flux above the urban area are confirmed. 2) The probabilities of constant-flux layer achievement (C. F.-rate) are 32.5%, 51.1%, 43.9% and 17.0%, for momentum, sensible-heat, latentheat and carbon dioxide flux, respectively. The C. F.-rate for all fluxes simultaneously is only 0.9%. 3) In this observation site, the C. F.-rate is less affected by the wind direction but slightly related to the atmospheric stability. 4) When a large-scale turbulence or front passes through a sensor, the sensible-heat flux ratio of 29m to 21m is diverted from 1.