Studies of Wind and Turbulence in Complex Terrain at Multiple Space-Time Scales

This dissertation concerns research on atmospheric surface layer within complex-terrain boundary layers, wherein data collected during two field experiments will be analyzed: 1) The U.S. Department of Energy’s (DOE) Wind Forecast Improvement Project 2 (WFIP2) that took place in the Columbia River Gorge and basin region (OR), and 2) The SWEX-Pilot experiment, a field campaign that took place in Santa Barbara (CA) between April-May 2020. The latter campaign was conducted by this author after the National Science Foundation (NSF)’s 2020 Sundowner Wind Experiment (SWEX) in Santa Barbara (CA) was postponed a few days before its official start (April 1^st 2020) because of the presence of the new (at the time) COVID-19 virus in CA.

The main goal of WFIP2 was to improve wind energy forecasts in regions of Complex Terrain by improving physical parameterizations of Numerical Weather Prediction (NWP) models. In this thesis, the variability of turbulent fluxes at the sub-grid scales of NPW models in regions of Complex Terrain, as well as the applicability of Monin-Obukhov (MO) theory and the skill of idealized Surface-Layer (SL) parameterizations that rely on it was studied. The goal of the 2020 SWEX Experiment was to study the spatio-temporal characteristics of Sundowner Winds – a dangerous weather condition that may intensify wildfires in Coastal Santa Barbara, CA. Notwithstanding the limited instrumentation deployed during the 2020 SWEX – Pilot experiment, the collected dataset could be used along with operational data of the National Weather Service (NWS) to identify days with sundowner winds and study small-scale weather phenomena in the Santa Ynez Valley (SYV) and in the lee of the Santa Ynez Mountains (SYM) in Santa Barbara County (CA) during sundowners with strong synoptic-to mesoscale forcing.