A note on estimating the height of the convective internal boundary layer near shore

Abstract

When cool air flows from the sea over a warm coast, the air is thermally modified. It is shown that h = cX"a, where h is the height (in meters) of this thermal or convective internal boundary layer (CIBL) over the coast,Xis the distance downwind (in meters) from the shoreline (i.e., the fetch), and c is a coefficient that relates to the shear velocity and wind speed inside the CIBL, potential temperature difference and entrainment coefficient across the CIBL, and the lapse rate outside the CIBL. This equation is a simplification of a theoretical equation and is supported by three similar formulations based on thermodynamic and dimensional analyses. Pertinent field experiments conducted near shorelines in France, Sweden, and Japan indicate that c is approximately 1.91, with a standard deviation of 0.38. All observations are within 95% confidence limits.

Wintertime boundary-layer structure and air–sea interaction over the Japan/East Sea

“…Because of the decrease in z i discussed above, the first data point from 000218 and the first two data points from 000203 were excluded from the fits. The growth rate of 2:06 m 1=2 obtained for 000203 is somewhat close to the 1:91 m 1=2 found near shore by Hsu (1986). The higher growth rate of 2:49 m 1=2 found for 000218 may be the result of the more intense CAO conditions prevailing on that day.…”

Surface energy balance, parameterizations of boundary-layer heights and the application of resistance laws near an Antarctic Ice Shelf front

“…xo.5 , (6) with x as the fetch over the water (Andreas et al, 1979;Stunder and Sethuraman, 1985;Hsu, 1986). According to Hsu (1986), the proportionality factor is given by (7) where r denotes the mean lapse rate of the flow over the ice shelf, CD is the drag coefficient, F = 0.2 (an entrainment parameter) and A0 is the difference in surface temperatures between ice shklf and polynya.…”

“…Inhomogeneities of the surface, as can be found in the vicinity of the ice shelf front, are responsible for internal boundary layers (IBL). Parameterizations for the IBL height are often based on the first law of thermodynamics (Andreas et al, 1979;Stunder and Sethuraman, 1985;Hsu, 1986;Raabe, 1986).…”

The internal boundary layer ? A review

“…In the case of mesoscale flow, and specifically the thermal IBL at the coast, models for the convective IBL and growth relations have been discussed by Venkatram (1977Venkatram ( , 1986 Stunder and Sethuraman (1985), Bergstrom (1986), Hsu (1986), supported by observational studies of, e.g., Echols and Wagner (1972), Raynor et al (1979), Gamo et al (1982), Bergstrom et al (1988) and Durand et al (1989). For the stably-stratified thermal IBL, Mulhearn (1981), Hsu (1983Hsu ( , 1989 and Doran and Gryning (1987) compared observations of the IBL depth with simple formulations.…”