Accession Number : ADA479824


Title :   Evaluation of Daytime Boundary Layer Heights from a Mesoscale Model Using Profilers/RASS Measurements


Descriptive Note : Master's thesis


Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA


Personal Author(s) : Bloch, Lindsay A.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA479824


Report Date : 01 MAR 2008


Pagination or Media Count : 91


Abstract : This thesis study focuses on the evaluation of the boundary layer height (BLH) diagnosed from a mesoscale model in comparison to wind profiler/Radio Acoustic Sounding System (RASS) measurements from the profiler site at Miramar Marine Corps Station (MMR). This objective is met through validation of the observed BLH and evaluations of the model BLH using the observed BLH's. In particular, two methods, one uses Signal-to-Noise-Ratio (SNR) from the profiler, and the other uses the vertical gradient of virtual potential temperature from RASS, were developed to detect BLH from the profiler/RASS systems. The detected BLH was validated against BLH from rawinsonde measurements. The SNR method gives a better mean BLH in the clear convective unstable BL's while the gradient method shows better correlation with the rawinsonde BLH. The Weather Research and Forecasting (WRF) model for the inland location (MMR) was compared to these profiler BLH estimates. Although WRF reasonably predicts the general BL behavior, WRF underestimated the BLH by several hundred meters. The WRF diagnosed BLH using the bulk Richardson number was inconsistent with the WRF predicted BL thermodynamics structure. An alternative BLH detection scheme using a gradient method of BLH detection is proposed and tested for WRF, showing better results.


Descriptors :   *SIGNAL TO NOISE RATIO , *BOUNDARY LAYER , *WEATHER FORECASTING , *HEIGHT , MEASUREMENT , VALIDATION , ACOUSTIC PROPERTIES , RICHARDSON NUMBER , RADIOSONDES , ACOUSTIC DETECTION , THESES , WIND , THERMODYNAMICS


Subject Categories : METEOROLOGY
      ACOUSTIC DETECTION AND DETECTORS
      FLUID MECHANICS
      RADIOFREQUENCY WAVE PROPAGATION


Distribution Statement : APPROVED FOR PUBLIC RELEASE