Transfer Coefficients of Momentum, Heat and Water Vapour in the Atmospheric Surface Layer of a Large Freshwater Lake.

In studies of lake-atmosphere interactions, the fluxes of momentum, water vapour and sensible heat are often parametrized as being proportional to the differences in wind, humidity and air temperature between the water surface and a reference height above the surface. Here, the proportionality via transfer coefficients in these relationships was investigated with the eddy-covariance method at three sites within an eddy-covariance mesonet across Lake Taihu, China. The results indicate that the transfer coefficients decreased with increasing wind speed for weak winds and approached constant values for strong winds. The presence of submerged macrophytes reduced the momentum transfer (drag) coefficient significantly. At the two sites free of submerged macrophytes, the 10-m drag coefficients under neutral stability were 1.8 $$(\pm \,0.4) \times \,10^{-3}$$ and $$1.7\,(\pm \,0.3) \times \,10^{-3 }$$ at the wind speed of $$9\,\text{ m } \text{ s }^{-1}$$ , which are 38 and 34 % greater than the prediction by the Garratt model for the marine environment. [ABSTRACT FROM AUTHOR]