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Hurricane Matthew (2016) was a category 5 hurricane that interacted with remote terrain over northern South America in the early stages of its life cycle. Because tropical cyclone (TC) precipitation and convection are known to be crucial factors in the understanding and forecasting of TC intensity, this study investigates how this terrain impacted Hurricane Matthew's rainband structure. Remote terrain is hypothesized to play a role in the strength of TC rainband convection by modifying the thermodynamic environment such that subsiding dry air advects over an extremely moist ocean surface layer leading to increased moist static instability. To investigate this hypothesis, this study utilizes the Advanced Research Weather and Research Forecasting Model (WRF-ARW) to create a high-resolution (2-km horizontal grid spacing) control simulation (CTL) of Hurricane Matthew and a second experimental simulation with a 50% reduction of terrain height over the topography of northern South America (T50). This study focuses on a particular convective rainband positioned downstream of the terrain that displayed prolonged robust convection during the initial stages of Hurricane Matthew's life cycle. Results indicate that characteristics of this robust rainband are consistent with prior research on an inner core rainband called a principal rainband. This rainband does not display differences in intensity in the two simulations but is located closer to the TC center and more persistent in the control simulation. In the region downstream of the topography, significantly (p < 0.05) drier conditions exist in the control simulation, which is consistent with the hypothesis that downslope motion would lead to a drier air mass. TC structural changes are also apparent, with a weaker TC in the reduced topography simulation. This research emphasizes the potentially important role of terrain distant from the TC center with possible influences on TC rainband convection and warm core structure. Conclusions of this research are limited due to the small sample size of a single case study. An ensemble modeling study and additional cases are needed for a more thorough conclusion on the impact of remote terrain on TC structure. / Master of Science / Predicting the intensity of hurricanes remains a monumental challenge for hurricane forecasters. Many factors can influence the intensity of hurricanes, including the strength, frequency, and spatial distribution of hurricane rainbands (band of precipitation). The hypothesis for this study is that terrain distant from the hurricane center can alter the hurricane environment and cause more frequent and stronger rainbands to form. To assess this hypothesis, I use a weather model to simulate Hurricane Matthew (2016) while it was interacting with remote terrain over northern South America on September 30 - October 1, 2016. Then I use the same model, but with terrain height reduced by 50% over northern South America and analyze the similarities and differences in the hurricane structure and rainband patterns. The results of this study suggest that terrain did not alter the peak rain rates in the hurricane rainbands but may have caused more frequent, widespread, and prolonged precipitation. Also, differences in hurricane structure were apparent when comparing the two model simulations. The reduced terrain simulation produced a weaker hurricane, lending some evidence to support the hypothesis that terrain may have played a role in altering the hurricane structure. These results demonstrate the potential importance of distant terrain on forecasting hurricane precipitation and intensity.

Kwok Chun-yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves [121]-122). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Experimental data --- p.7 / Chapter 2.1 --- Turbulent Convection using Helium --- p.7 / Chapter 2.2 --- Turbulent Convection using water --- p.8 / Chapter 3 --- Probability Distribution and Scaling behavior --- p.9 / Chapter 3.1 --- PDF of YT --- p.9 / Chapter 3.1.1 --- Helium Convection --- p.10 / Chapter 3.1.2 --- Water Convection --- p.26 / Chapter 3.1.3 --- Comparison between helium data and Water data --- p.34 / Chapter 3.2 --- T -dependence of the moments of XT --- p.39 / Chapter 3.2.1 --- Helium Convection --- p.39 / Chapter 3.2.2 --- Water Convection --- p.47 / Chapter 4 --- Hierarchical Moment Relation --- p.50 / Chapter 4.1 --- Method of Analysis --- p.50 / Chapter 4.2 --- Results and Discussion --- p.53 / Chapter 4.2.1 --- Helium Convection --- p.53 / Chapter 4.2.2 --- Water Convection --- p.81 / Chapter 5 --- Discussion and Conclusion --- p.95 / Chapter 5.1 --- Passive Scalar --- p.96 / Chapter 5.2 --- Comparison between Turbulent Convection and Passive Scalar --- p.99 / Chapter 5.3 --- Scaling behavior for length scale above and below the Bolgiano scale for turbulent convection using Helium gas --- p.100 / Chapter 5.4 --- Conclusions --- p.107 / Chapter A --- The lognormal model --- p.108 / Chapter B --- Definition of XT --- p.110 / Chapter C --- Reasons for analysis of (xTp) for p≤ 12 --- p.112 / Chapter D --- Functional form of μp implied by the hierarchical relation --- p.119 / Bibliography --- p.122

Zhou Sheng-qi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 66-70). / Text in English; abstracts in English and Chinese. / Zhou Sheng-qi. / Abstract (in Chinese) --- p.i / Abstract (in English) --- p.ii / Acknowledgement --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.viii / Chapter / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Turbulence: a Universal Problem --- p.1 / Chapter 1.2 --- Rayleigh-Benard Convection --- p.2 / Chapter 1.2.1 --- The History of Rayleigh-Benard Convection --- p.2 / Chapter 1.2.2 --- The Dimensionless Parameters --- p.4 / Chapter 1.2.3 --- The Physical Picture of Turbulent Convection --- p.5 / Chapter 1.3 --- Motivation of This Study --- p.8 / Chapter 2. --- Theoretical Base and Experimental Setup --- p.11 / Chapter 2.1 --- The Rayleigh-Benard problem --- p.11 / Chapter 2.1.1 --- The Boussinesq approximation --- p.11 / Chapter 2.1.2 --- The Convection Equation --- p.13 / Chapter 2.2 --- Experimental Setup and Measurement --- p.14 / Chapter 2.2.1 --- The Convection Cell --- p.14 / Chapter 2.2.2 --- The Power Supply and the Refrigerated Recirculator --- p.19 / Chapter 2.2.3 --- The Temperature Probes --- p.19 / Chapter 2.2.4 --- The Temperature Measurement System --- p.20 / Chapter 2.2.5 --- Building up the Convection State --- p.25 / Chapter 3. --- Temperature Power Spectra and the Viscous Boundary Layer in the Thermal Turbulence --- p.27 / Chapter 3.1 --- The Power Spectra Method --- p.27 / Chapter 3.2 --- The Suspicions of the Power Spectra Method --- p.30 / Chapter 3.3 --- Discussion of the Experimental Results --- p.32 / Chapter 3.4 --- Summary --- p.39 / Chapter 4. --- The Correlation Function of Temperature --- p.40 / Chapter 4.1 --- Preparation of Experiment --- p.41 / Chapter 4.1.1 --- Apparatus --- p.41 / Chapter 4.1.2 --- Definition of correlation function --- p.41 / Chapter 4.2 --- Results and Discussion --- p.44 / Chapter 4.2.1 --- The Delay Time (¡’0) --- p.47 / Chapter 4.2.2 --- The Maximum Correlation Coefficient (R) --- p.52 / Chapter 4.2.3 --- The Half Width (¡’h) --- p.58 / Chapter 4.3 --- Summary --- p.61 / Chapter 5. --- Conclusions --- p.63 / References --- p.66

Zhou Quan = 关於热湍流中标量场混合和自组织结构的实验研究 / 周全. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 89-94). / Text in English; abstracts in English and Chinese. / Zhou Quan = Guan yu re tuan liu zhong biao liang chang hun he he zi zu zhi jie gou de shi yan yan jiu / Zhou Quan. / Abstract --- p.ii / Acknowledge --- p.iii / Table of Contents --- p.v / List of Figures --- p.xii / List of Tables --- p.xiii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Rayleigh-Benard System --- p.2 / Chapter 1.1.1 --- Physics Picture --- p.2 / Chapter 1.1.2 --- Basic Equations and Characteristic Parameters --- p.3 / Chapter 1.2 --- Passive and Active Scalars --- p.6 / Chapter 1.3 --- Large-Scale Circulation (LSC) --- p.7 / Chapter 2 --- Passive and Active Scalars in Convective Thermal Turbulence --- p.9 / Chapter 2.1 --- Experimental Setup and Measurement Techniques --- p.9 / Chapter 2.1.1 --- Rectangular Cell --- p.9 / Chapter 2.1.2 --- Temperature probe: thermistor --- p.12 / Chapter 2.1.3 --- Laser Induced Fluorescence (LIF) --- p.16 / Chapter 2.2 --- Passive Scalar Measurements --- p.24 / Chapter 2.2.1 --- Concentration Time Series --- p.24 / Chapter 2.2.2 --- Statistical Properties --- p.26 / Chapter 2.3 --- Active Scalar Measurements --- p.35 / Chapter 2.4 --- Relationship between passive scalar and active scalar --- p.41 / Chapter 2.4.1 --- Cross-correlation Functions --- p.41 / Chapter 2.4.2 --- Structure Functions --- p.48 / Chapter 2.5 --- Summary --- p.60 / Chapter 3 --- The Azimuthal Motion of the Mean Wind in Turbulent Rayleigh- Benard Convection --- p.63 / Chapter 3.1 --- Experimental Setup and Measurement Techniques --- p.64 / Chapter 3.1.1 --- Cylindrical Cell --- p.64 / Chapter 3.1.2 --- Particle Image Velocimetry (PIV) --- p.65 / Chapter 3.2 --- Azimuthal Motion of the Mean Wind in the Γ = 1.0 Cell --- p.68 / Chapter 3.2.1 --- Time-trace of the LSC orientation Φ --- p.69 / Chapter 3.2.2 --- Statistical properties of azimuthal motion of the mean wind --- p.73 / Chapter 3.3 --- Azimuthal Motion of the Mean Wind in theΓ = 0.5 Cell --- p.77 / Chapter 3.3.1 --- Time-trace of the LSC orientation Φ --- p.78 / Chapter 3.3.2 --- Statistical properties of azimuthal motion of the mean wind --- p.80 / Chapter 3.4 --- Summary --- p.85 / Chapter 4 --- Conclusion --- p.86 / Chapter 4.1 --- Scalar Mixing --- p.86 / Chapter 4.2 --- The Azimuthal Motion of the LSC --- p.87 / Chapter 4.3 --- Perspective for Further Investigation --- p.88 / Bibliography --- p.88

A distinct feature of Rayleigh-Benard(RB) convection is the existence of a self-organized large-scale circulatory flow(LSC), also known as the "mean wind" of turbulence. This thesis is an experimental investigation of this LSC by using the particle image velocimetry and multi-thermal probe method. We studied the various aspects of the LSC, including the azimuthal motion, the flow cessation and reversal and the reorientation of the LSC, in aspect ratio(Gamma) 1, 1/2 and 1/3 cells, where Gamma is the ratio between the diameter and the height of the cylindrical convection cells. Also studied in the thesis are the different flow modes and the flow mode transitions for these different geometries. / It is found in Gamma = 1 cells the azimuthal motion consists of erratic fluctuations and a time-periodic oscillation. While in Gamma = 1/2 cells, this kind of oscillation is missing. An intriguing dynamic feature of the LSC is the apparently erratic large orientational change of its nearly vertical circulation plane, which is called reorientation. The occurrence of the reorientations are both Poisson process for the Gamma = 1 and 1/2 geometries. We found that the azimuthal motion of LSC is more confined in larger Gamma geometry, and this property can be used to interpret the so-called bimodality of heat transport. / The reversal of the flow direction of the LSC in RB system resembles a lot of reversal phenomena and is the interest of several theoretical models. We found, in Gamma = 1/2 geometry, that there are an order of magnitude more cessations and reversals than that in Gamma = 1 geometry, which contrasts sharply to the finding in Gamma = 1 geometry. Thus in Gamma = 1/2 cells a statistically significant number of unambiguously identified pure reversal events are obtained, which allow us to analyze several important properties of pure reversal events. It is found that the occurrence of reversals is a Poisson process and that a stronger rebound of the flow strength after a reversal/cessation leads to a longer period of stability of the LSC. Several properties of reversals/cessations in this system are found to be statistically similar to those of geomagnetic reversals. / We found in all the aspect ratios explored(Gamma = 1, 1/2 and 1/3) both single circulating roll flow structure and two vertically stacked counter-rotating rolls structure exist. The average percentage of time that the flow spends in the single-roll mode (SRM) is decreasing with Gamma while that of the double-roll mode (DRM) is increasing with Gamma. Several routes of transitions among the different flow modes are identified. We also show direct evidence that the SRM is more efficient for heat transfer than the DRM. It is also found that the time interval between successive flow mode transitions has an exponential distribution, suggesting a Poisson process for the underlying dynamics. / Xi, Hengdong = 熱湍流中的大尺度環流 / 郗恒東. / "July 2007." / Adviser: Ke-Qing Xia. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0386. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 144-153). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307. / Xi, Hengdong = Re tuan liu zhong de da chi du huan liu / Xi Hengdong.

Ko, Tze Cheung = 均勻湍流對流殼模型內的熱傳送及雷諾數標度律 / 高子翔. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 76-78). / Abstracts in English and Chinese. / Ko, Tze Cheung = Jun yun tuan liu dui liu ke mo xing nei de re chuan song ji Leinuo shu biao du lü / Gao Zixiang. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Description of Rayleigh-Benard convection --- p.2 / Chapter 1.2 --- Interesting issues in turbulent Rayleigh-Benard convection --- p.3 / Chapter 2 --- Earlier studies of heat transport in Rayleigh-Benard convection --- p.6 / Chapter 2.1 --- Marginal stability arguments --- p.7 / Chapter 2.2 --- The Chicago mixing zone model --- p.8 / Chapter 2.3 --- Shraiman and Siggia theory --- p.10 / Chapter 2.4 --- Grossmann and Lohse theory --- p.12 / Chapter 2.4.1 --- Estimating the kinetic dissipation rates due to boundary layer and bulk --- p.13 / Chapter 2.4.2 --- Estimating the thermal dissipation rates due to boundary layer and bulk --- p.13 / Chapter 2.4.3 --- The four regimes --- p.15 / Chapter 2.5 --- The asymptotic limit of very high Ra --- p.17 / Chapter 3 --- The shell model used --- p.20 / Chapter 3.1 --- Background of shell models of turbulence --- p.20 / Chapter 3.2 --- The model used --- p.22 / Chapter 3.2.1 --- The Brandenburg model --- p.22 / Chapter 3.2.2 --- The requirement of a large scale drag term --- p.23 / Chapter 3.3 --- Previous work on the Brandenburg model --- p.24 / Chapter 4 --- "Definitions of Ra, Nu, and Re and two exact results" --- p.26 / Chapter 4.1 --- Heat transport study using shell model --- p.26 / Chapter 4.2 --- Two exact results --- p.28 / Chapter 5 --- Results and discussions --- p.29 / Chapter 5.1 --- Parameters used --- p.29 / Chapter 5.2 --- "Nu(Ra,Pr) and Re(Ra,Pr) scaling results" --- p.29 / Chapter 5.3 --- "Scaling results of ε, εdrag and x" --- p.32 / Chapter 5.4 --- Physical meaning of the drag term --- p.35 / Chapter 5.5 --- Understanding the dependence of ε on Re --- p.36 / Chapter 5.6 --- Understanding the dependence of x and εdrag on Re and Pr --- p.40 / Chapter 5.7 --- The form of the added drag term --- p.41 / Chapter 6 --- Possible changes of Nu and Re due to non-Boussinesq effects --- p.43 / Chapter 6.1 --- Background --- p.43 / Chapter 6.2 --- Method of study --- p.44 / Chapter 6.3 --- Effects due to the temperature dependence of kinematic viscosity --- p.45 / Chapter 6.4 --- Effects due to the temperature dependence of thermal diffusivity --- p.50 / Chapter 6.5 --- Effects due to the temperature dependence of volume expansion coefficient --- p.55 / Chapter 6.6 --- Understanding the scaling behavior under non-Boussinesq effects --- p.61 / Chapter 6.6.1 --- Scaling behavior of x on Re --- p.61 / Chapter 6.6.2 --- Scaling behavior of εtotai on Re --- p.65 / Chapter 6.6.3 --- Scaling behavior of Nu and Re on Ra --- p.66 / Chapter 6.7 --- Summary and future work --- p.68 / Chapter 7 --- Conclusion --- p.69 / Chapter A --- Height independence of Nu for homogeneous turbulent convection with periodic boundary conditions --- p.73 / Chapter B --- "Height independence of (uz)A,t for homogeneous turbulent convection with periodic boundary conditions" --- p.75 / Bibliography --- p.76