Vertical Structure and Flux Formulations for the Stable Boundary Layer
Abstract
A z-less form of the mixing length that approaches surface layer similarity theory at the surface and approaches boundary layer similarity theory for weakly stratified conditions performed significantly better for CASES99 data than five other existing formulations, particularly after accounting for self-correlation. Radiative flux divergence was important for the initial formation of the surface inversion layer in CASES99, but was otherwise unimportant. Based on several data sets, the success of Monin-Obukhov similarity theory with moderate and strong stability is mainly attributed to self-correlation. The use of existing methods for computing fluxes with very weak turbulence in stable conditions is completely inadequate due to inadvertent inclusion of mesoscale motions and large random flux errors. More careful calculation of turbulence quantities for these conditions leads to extremely weak, but well behaved, turbulence fluxes. Intermittent turbulence patches are found to evolve and decay on small time scales and cannot be studied from a single tower. They advect past individual towers in various states of evolution and decay, which is one of several causes of the poor relationship between turbulence and the Richardson number. Well-defined intermittent events seen in textbooks are in practice relatively rare. Most intermittency assumes a more complex behavior.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 2005
- Accession Number
- ADA433682
Entities
People
- Cheryl Klipp
- Dean Vickers
- Larry J. Mahrt
Organizations
- Oregon State University