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Downloaded From MIDLATITUDE CIRRUS CLOUD STRUCTURAL PROPERTIES ANALYZED FROM THE EXTENDED FACILITY FOR ATMOSPHERIC REMOTE SENSING DATASET A THESIS Presented to the Faculty of the University of Alaska Fairbanks in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY By Likun Wang, B.S., M.S. Fairbanks, Alaska August 2004 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 3147368 Copyright 2005 by Wang, Likun All rights reserved. INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. ® UMI UMI Microform 3147368 Copyright 2005 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. MIDLATITUDE CIRRUS CLOUD STRUCTURAL PROPERTIES ANALYZED FROM THE EXTENDED FACILITY FOR ATMOSPHERIC REMOTE SENSING DATASET By Likun Wang, B.S., M.S. RECOMMENDED: V c . Dr. David O’C, Starr, NASA Goddard Research Center Dr. Glen Shaw, UAF CO fNdaJusir _ Dr. Nicole Molders, UAF n ^ Dr. Cathy Cahill, UAF " ^ 5 ^ — Dr. Kenneth Sassen, Advisory Committee Chair £j 2 u w T Head, Program in Atmospheric Sciences APPROVED: Dean, College of Science, Engineer og and Mathematics Dean of the Graduate School A Date Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT The knowledge on cirrus inhomogeneous structural properties is important not only in radiation calculations, but also in deeply understanding the dynamics mechanism including the formation, development, and dissipation of cirrus clouds. The midlatitude cirrus inhomogeneous structural properties have been evaluated by analyzing the 10-year high cloud datasets obtained at the University of Utah, Facility for Atmospheric Remote Sensing in Salt Lake City, UT. Three goals have been reached in this research. First, the means to analyze lidar data using wavelet analysis, an advanced approach to obtain information on the structure of cirrus clouds, has been successfully developed. And then, typical cirrus structures including Kelvin-Helmholtz instabilities, cirrus mammata, and the uncinus cells have been analyzed by case studies and statistical survey. Their dynamical mechanisms, environmental characteristics, and vertical and horizontal length scale have been studied. Thirdly, using the method based on the wavelet transform and other methods, a climatology of midlatitude cirrus horizontal inhomogeneous properties is developed from the FARS lidar backscattered power data, the proxies of real cirrus clouds. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS Signature .....................................................................................................................................i Title............................................................................................................................................ ii Abstract .....................................................................................................................................iii Table of Contents .....................................................................................................................iv List of Figures .......................................................................................................................... ix List of Tables ......................................................................................................................... xiv List of Acronyms ..................................................................................................................xxii Acknowledgements ............................................................................................................. xviii Chapter 1 Introduction .............................................................................................................1 1.1 Cirrus Clouds: General Knowledge ..................................................................... 1 1.2 Importance of Inhomogeneity of Cirrus Clouds on Radiation Transfer 7 1.3 Review of Inhomogeneous Structures in Cirrus Clouds .................................. 12 1.3.1 Turbulence ..........................................................................................14 1.3.2 Mammata............................................................................................ 14 1.3.3 KH instabilitie s ...................................................................................18 1.3.4 Cloud-scale convective and organized uncinus cells ......................19 1.3.5 Gravity waves .................................................................................... 20 1.3.6 Other mesoscale organizations ......................................................... 22 1.4 The Goal of This Research ................................................................................ 22 Chapter 2 The Facility for Atmospheric Remote Sensing: Instruments and Dataset 25 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. V 2.1 Cloud Polarization Lidar .................................................................................... 28 2.1.1 Instrument description .......................................................................28 2.1.2 Lidar equation .................................................................................... 29 2.1.3 CPL high cloud dataset ......................................................................31 2.2 Polarization Diversity Lidar ............................................................................... 35 2.2.1 Instrument description .......................................................................35 2.2.2 PDL high cloud dataset ......................................................................35 Chapter 3 Preliminary data analysis methods and wavelet transform ................................37 3.1 The Procedure of Data Preliminary Processing ................................................37 3.1.1 Lidar signal record errors and data rejection scheme ..................... 37 3.1.2 Lidar data preliminary processing .....................................................39 3.1.3 Transforming the time series to spatial series ..................................41 3.1.4 Detectable length scale range ............................................................ 46 3.2 Wavelet Transform Methods ............................................................................. 48 3.2.1 'Why wavelet? From Fourier transform to wavelet transform 48 3.2.2 The mathematical view of WT algorithms ...................................... 50 3.2.3 The choice of the wavelet function ...................................................54 Chapter 4 Kelvin-Helmholtz Instabilities ............................................................................ 57 4.1 Introduction ..........................................................................................................57 4.2 Theoretical Background ..................................................................................... 64 4.2.1 Necessary condition for instability ...................................................67 4.2.2 Howard semicircle theorem .............................................................. 68 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 4.2.3 Growth rate ........................................................................................ 69 4.3 A Case Study of KH Instabilities .......................................................................70 4.4 KH Instabilities Observed from FARS High Cloud Dataset ...........................80 4.4.1 Cirrus cloud type associated with KH instabilities ......................... 80 4.4.2 Occurrence height of KH instabilities ...............................................83 4.4.3 Environmental characteristics of KH instabilities .......................... 89 4.4.4 Wave characteristics of KH instabilities .......................................... 92 4.5 Conclusion ...........................................................................................................97 Chapter 5 Cirrus Mammata .................................................................................................. 99 5.1 Introduction ..........................................................................................................99 5.2 Case Study.........................................................................................................102 5.2.1 Synoptic weather settings and environmental characteristics 103 5.2.2 Observation and analysis results ..................................................... 109 5.2.3 Discussion of case study .................................................................123
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