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Author
Description
Despite the general applicability of classical Ekman theory, individual observations of wind veering in the planetary boundary layer seldom exhibit the typical spiral turning with height. This study attempts to assess the reasons for these deviations from theory which occur not only as large fluctuations in time but also as significant differences in mean profiles from one location to another.
Author
Description
A dry, two-dimensional version of the Colorado State University Multi-Dimensional Cloud/Mesoscale Model was used to simulate the cross-valley dynamic and thermodynamic structure in deep mountain valleys during the morning transition period when the nocturnal inversion is destroyed.
Author
Description
A one-layer bulk boundary layer model is developed following earlier work by Randall and Moeng. The model predicts the mixed layer values of the potential temperature, mixing ratio, and u- and v-momentum. The model also predicts the depth of the boundary layer and the vertically integrated turbulence kinetic energy (TKE).
Author
Description
Bulk models of the planetary boundary layer (PBL) conventionally rely on diagnostic forms of the turbulence kinetic energy (TKE) equation to determine the entrainment rate. During episodes of rapid deepening or shallowing, the local time rate of change of the vertically integrated TKE becomes significant compared to the difference between gross production and dissipation. A method is presented to determine the entrainment rate in a bulk PBL model...
Author
Description
This paper presents a diagnostic study of two models proposed by Betts (1973a). The first was a model for a well-mixed sub-cloud layer capped by a more stable transition layer. The downward heat flux at the base of this transition layer is here estimated from the thermal structure of the layer to be 15-25% of the surface sensible heat flux. The second model was a model for a two layer lapse-rate structure for the cumulus layer. A sensitivity analysis...
16) Observed characteristics of turbulence in the atmospheric boundary layer over mountainous terrain
Author
Description
This study examines the location and development of turbulence in the morning hours of boundary layer development over mountainous terrain. Four case study days are presented which illustrate important features on two types of days observed in the mountains of central Colorado.