A case study of high winds induced by upper-level frontogenesis and tropopause folding
Burke, Sara T.
Pauley, Patricia M.
MetadataShow full item record
High surface winds over California and the bordering Pacific Ocean resulted in the death of one man and the loss of power to approximately 50,000 residences across the state. These damaging winds are hypothesized to result from an upper level front and associated tropopause folding that rapidly intensify as they move south across the region, causing high momentum air to be transported to the lower troposphere. Once the high momentum air reaches the top of the planetary boundary layer, the combined effects of destabilization of the planetary boundary layer by cold air advection aloft and shear induced turbulence at the top of the layer provide the initial mechanism by which the high momentum air is entrained into the layer and mixed to the surface. After sunrise, convectively driven turbulence provides an additional source of mixing in the planetary boundary layer. The high surface winds have a strong cross isobaric component in the direction of the upper level winds, and the upper level frontal movement to the south over central California is synchronous with the increase of surface winds over the same region. The winds decrease as the upper level front moves into the base of the upper level trough and the high momentum source in the lower troposphere disappears.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Towle, Wendy A. (Monterey, California. Naval Postgraduate School, 2001-12);To investigate planetary and topographic beta effects on classical as well as unique features in the northern Canary Current system (NCCS), several numerical experiments using the Princeton Ocean Model are explored. To ...
Tworek, Troy J. (Monterey, California. Naval Postgraduate School, 2000-09);To investigate the effect of the role played by planetary beta in the generation and maintenance of the Leeuwin Current System (LCS), several numerical experiments are conducted with varying Coriolis parameterizations (f- ...
Chang, C.-P.; Li, Tim (2000-07-15);The key questions of how the tropospheric biennial oscillation (TBO) maintains the same phase from northern summer in South Asia to southern summer in Australia, and how the reversed phase can last through three locally ...