Extended Abstract (164K)P6.18
Interaction between wind and temperature fields under the heterogeneous heat flux in the planetary boundary layer
Hyoung-Jin Kim, Yonsei University, Seoul, Korea; and Y. Noh and S. Raasch
Interaction between wind and temperature fields under the heterogeneous heat flux was investigated by using large eddy simulation (LES) of the planetary boundary layer (PBL). It has shown that the substantial difference exists in the wind and temperature fields, depending on whether the directions of the background wind and the surface heat flux variation are parallel or perpendicular.
When they are parallel to each other, the temperature and velocity structures influenced by the inhomogeneous heat flux, such as two-dimensional plumes, are destroyed more easily by the background wind, while the horizontal velocity fields due to the background wind are more strongly modified by convection. This leads to the noticeable difference in the profiles of horizontal and vertical turbulent kinetic energy, the mean velocity and temperature, and heat flux.
This also results in the difference in the bottom friction and the entrainment at the top of the PBL, which have important implications in the PBL modeling. Meanwhile the difference between two cases disappears when the background wind velocity becomes sufficiently large as much as 15.0 ms-1.
Poster Session 6, BLs over Heterogeneous Surfaces; Coupled Surface - BL Studies
Thursday, 18 July 2002, 2:00 PM-2:00 PM
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