UC San Diego UC San Diego Electronic Theses and Dissertations Title Northerly surface wind events over the eastern North Pacific Ocean : spatial distribution, seasonality, atmospheric circulation, and forcing Permalink https://escholarship.org/uc/item/62x1f76v Author Taylor, Stephen V. Publication Date 2006 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, SAN DIEGO Northerly surface wind events over the eastern North Pacific Ocean: Spatial distribution, seasonality, atmospheric circulation, and forcing A Dissertation submitted in partial satisfaction of the requirement for the degree Doctor of Philosophy in Oceanography by Stephen V. Taylor Committee in charge: Professor Konstantine Georgakakos, Chair Professor Daniel Cayan, Co-Chair Professor Scott Ashford Professor Walter Munk Professor Joel Norris 2006 Copyright Stephen V. Taylor, 2006 All rights reserved. SIGNATURE PAGE The Dissertation of Stephen V. Taylor is approved, and it is acceptable in quality and form for publication on microfilm: ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ Co-Chair ___________________________________________________________ Chair University of California, San Diego 2006 iii DEDICATION To all who maintain the interest and exert the effort to learn iv TABLE OF CONTENTS SIGNATURE PAGE............................................................................................................................... iii DEDICATION .........................................................................................................................................iv TABLE OF CONTENTS ..........................................................................................................................v ACKNOWLEDGEMENTS.....................................................................................................................vii VITA ........................................................................................................................................................ix ABSTRACT OF THE DISSERTATION.................................................................................................xi CHAPTER ONE........................................................................................................................................1 Northwesterly surface winds over the eastern North Pacific Ocean in spring and summer ......................1 1.1 Introduction .........................................................................................................................................2 1.1.1 Background ..................................................................................................................................2 1.1.2 Motivation ....................................................................................................................................3 1.2 Data .....................................................................................................................................................5 1.2.1 Buoy Winds..................................................................................................................................5 1.2.2 Satellite Scatterometer Winds.......................................................................................................6 1.3 Analysis...............................................................................................................................................8 1.3.1 Temporal Variability ....................................................................................................................9 1.3.2 Spatio-temporal Variability from Satellite Scatterometer Winds ...............................................12 1.3.3 Wind events, event evolution .....................................................................................................16 1.4 Concluding Remarks .........................................................................................................................18 CHAPTER TWO.....................................................................................................................................21 Structure and forcing of northerly surface wind events over the eastern North Pacific Ocean ...............21 2.1 Introduction ...................................................................................................................................22 2.1.1 Seasonal Mean Atmospheric Circulation from Global Reanalysis.........................................23 2.1.2 Possible mechanisms of wind events: Processes known to affect coastal wind .....................25 2.1.3 Organization ...........................................................................................................................33 2.2 Data ...............................................................................................................................................33 2.2.1 NCEP-NCAR Global Reanalysis (R-1)..................................................................................33 2.2.2 North American Regional Reanalysis (NARR)......................................................................34 2.3 Methods.........................................................................................................................................35 2.3.1 Composites .............................................................................................................................35 2.3.2 Self Organizing Maps (SOM).................................................................................................35 2.3.3 Composite Stability and SOM Analysis .................................................................................38 2.3.4 Case studies ............................................................................................................................39 2.4 Results ...........................................................................................................................................40 2.4.1 Composites of NCEP global Reanalysis Fields......................................................................40 2.4.2 Evidence of Upper-air Troughs During Wind Events ............................................................41 2.4.3 Evidence of Near-Surface Thermal Contrast across the Coast during Wind Events ..............43 2.4.4 Effect on Wind events of Terrain-Marine Boundary Layer (MBL) Interaction .....................45 2.5 Discussion .....................................................................................................................................47 2.5.1 Comments on Seasonal Differences .......................................................................................47 2.5.2 A New Hypothesis: Southeast Migration of the North Pacific High......................................50 2.6 Conclusions ...................................................................................................................................51 v CHAPTER THREE.................................................................................................................................56 Sensitivity Tests ......................................................................................................................................56 3.1 Introduction ...................................................................................................................................57 3.1.1 Introduction and Motivation for the Temperature Perturbation Sensitivity Test....................57 3.1.2 Introduction and Motivation for the Coastal Terrain Sensitivity Test ....................................60 3.1.3 Organization ...........................................................................................................................62 3.2 Data and Model .............................................................................................................................62 3.2.1 Data ........................................................................................................................................62 3.2.2 Model......................................................................................................................................62 3.3 Sensitivity Tests.............................................................................................................................63 3.3.1 Sensitivity Test One: Temperature Perturbation.....................................................................64 3.3.2 Sensitivity Test Two: Flat Coastal Terrain .............................................................................67 3.4 Conclusions ...................................................................................................................................69 DISSERTATION CONCLUSIONS AND RECOMMENDATIONS.....................................................72 TABLES..................................................................................................................................................75 FIGURES ................................................................................................................................................82 APPENDIX ...........................................................................................................................................118