Analytical model for the growth of the coastal internal boundary layer during onshore flow
A model of near-neutral and convective steady-state internal boundary layer evolution is presented. The model deals with the internal boundary layer that forms over land in coastal and lake areas during onshore winds. Near the ground, the growth of the internal boundary layer is controlled by friction velocity in accordance with surface layer theory. Further downwind, the growth is determined by the atmosphere stability and friction velocity within the internal boundary layer, and the temperature gradient in the air above. The wind profile inside the internal boundary layer is assumed to follow Obukhov similarity theory. An expression for the strength of the inversion that caps the layer is derived and used in the model. A comparison is carried out with independent experimental observations of internal boundary layer growth in the sea-land transition. Kinematic heat flux through the top of the internal boundary layer is described in terms of the convective and mechanical turbulence, using the Zilitinkevich correction, which dominates the growth process of the internal boundary layer when it is lower than roughly 50m. Conditions of high wind speed and large values of the potential temperature gradient over water result in a deep zone where the growth of the internal boundary layer is controlled by mechanical turbulence. With near-zero potential temperature gradient over water, the zone becomes shallow and may vanish.
Bibliographic Reference: Article: Quarterly Journal of the Royal Meteorological Society, Vol.116 (1990), pp. 187-203
Record Number: 199011125 / Last updated on: 1994-12-01
Original language: en
Available languages: en