Hong, Song-You, Jihyeon Jang, Hyeyum Hailey Shin, and
Junhong Lee, Yonsei University, Seoul, Korea
The eddy-diffusivity
scheme of Tiedtke is evaluated, focusing on the dependency upon the deep
convection schemes. Drying and warming near the top of the boundary layer and countering
effects its above are observed. These effects are pronounced over the oceans,
which leads to the modulation of tropical precipitation. It is found that the
Tiedtke scheme shows similar effects regardless of the choice of the deep
convection scheme. A revised scheme that explicitly couples the planetary
boundary layer and shallow convection, which is the revision to the TiedtkeÕs
approach, is proposed and evaluated. The new scheme incorporates the turbulent
properties in the boundary layer into the shallow convection process. It is
found that the simulated climatology in a global model is improved by reducing
the exaggerated mixing in the original Tiedtke scheme.