臺灣博碩士論文加值系統

輻射對流平衡（Radiative Convective Equilibrium, RCE）為熱帶大氣的氣候平均結果。在旋轉場之下達成的輻射對流平衡，即為RRCE（Rotating RCE），其結果將伴隨一個或多個TC（Tropical cyclone）。多TC並存可免除模式邊界對TC的影響，方法為增加水平模擬範圍大小，或增強旋轉場f。
本研究使用雲解析模式VVM來模擬RRCE，1024公里模擬範圍的實驗僅得到單一TC，3072公里模擬範圍則得到一個以上TC。在大範圍實驗中，藉由改變背景渦度場f與SST（Sea surface temperature）進行敏感度測試。強渦度場的TC大小與強度約略與SST成正比，TC數量與SST成反比；弱渦度場的TC個數少，TC強度受邊界影響。
在第一個TC形成前後，水氣極大值驟增，其上限由克勞─克拉方程控制，水氣極小值略降但大部分網格向極小值方向靠近，其下限由TC強度控制，即乾區變乾、溼區變溼、水氣往對流處集中的「對流集結（Convective aggregation）」特徵，SST愈大此現象愈明顯。
本研究以深度優先搜尋的連通元件標記法訂出獨立的雲元件，雲數均有先升後降的趨勢，因而定義發生雲數極大值的時間為對流集結時間。背景渦度場愈強，對流集結效率愈好。在對流集結時間前後，平均雲體積有顯著變化。
在TC旋生過程中，渦度熱塔（Vortical hot tower, VHT）扮演了重要角色。VHT雲數亦有先升後降的趨勢，且背景渦度場愈強下降得愈快。強渦度場在對流集結時間之後，VHT整體的體積均開始顯著增加，且SST愈大VHT往大雲集中的現象愈明顯。弱渦度場的VHT體積增幅相對較緩。
本研究歸納了理想數值實驗的對流集結現象的幾個特徵：雲的數量減少、雲的平均體積增加、水氣往對流處集結以致溼區更溼及乾區更乾。雲數極大值可以有效判斷對流集結的發生時間。

誌謝………………………………………………………………………………………i
摘要……………………………………………………………………………………...ii
英文摘要………………………………………………………………………………..iv
目錄……………………………………………………………………………………..vi
圖目錄………………………………………………………………………………….vii
表目錄…………………………………………………………………………………..xi

第一章　前言…………………………………………………………………………...1
第二章　模式與實驗設計…………………………………………………………….12
第一節　數值模式──VVM……………………………………………………12
第二節　理想化實驗設計……………………………………………………….12
第三節　連通元件標記法（Connected-component labeling）……………..….13
第三章　實驗結果…………………………………………………………………….15
第一節　SD實驗………………………………………………………………...15
第二節　LD實驗的TC定位、旋生時間、半徑與強度………………………19
第三節　整體水氣、風速、降水之分析……………………………………….34
第四節　雲量、雲數、雲體積分析…………………………………………….40
第五節　渦度熱塔（Vortical Hot Tower）……….…………………………….44
第四章　總結與未來展望…………………………………………………………….54
第五章　參考文獻…………………………………………………………………….57

Arakawa, A., and C. M. Wu, 2013: A Unified Representation of Deep Moist Convection in Numerical Modeling of the Atmosphere. Part I. J. Atmos. Sci., 70, 1977-1992.
Arnold, N. P., and D. A. Randal, 2015: Global-scale convective aggregation: implications for the Madden-Julian oscillation. J. Adv Model Earth Syst., 7, 1499-1518.
Boos, W. R., A. V. Fedorov, and L. Muir, 2015: Convective self-aggregation and tropical cyclogenesis under the hypohydrostatic rescaling. J. Atmos. Sci., 73, 525-544.
Bretherton, C. S., P. N. Blossey, M. F. Khairoutdinov, 2005: An energy-balance analysis of deep convective self-aggregation above uniform SST. J. Atmos. Sci., 62, 4273-4292.
Chavas, D.R., and K. A. Emanuel, 2013: Equilibrium Tropical Cyclone Size in an Idealized State of Axisymmetric Radiative-Convective Equilibrium. J. Atmos. Sci., 71, 1663-1680.
Chen, Y.C., 2016: Cloud Characteristics of Aggregated Shallow Convection in MJO Suppressed Phase Using CRM Simulations. Master thesis, Graduate Institute of Atmospheric Sciences College of Science, National Taiwan University.
Chien, M. H., and C. M. Wu, 2016: Representation of topography by partial steps using the immersed boundary method in a vector vorticity equation model (VVM). J. Adv. Model Earth Syst., 8, 212-223.
Davis, C. A., 2015: The formation of moist vortices and tropical cyclones in idealized simulations. J. Atmos. Sci., 72, 3499-3516.
Emanuel, K. A., 1986: An air-sea interaction theory for tropical cyclones. Part I: Steady state maintenance, J. Atmos. Sci., 43, 585-604.
Held, I. M., R. S. Hemler, and V. Ramaswamy, 1993: Radiative-convective equilibrium with explicit two-dimensional moist convective. J. Atmos. Sci., 50, 3909-3927.
──, M. Zhao, and B. Wyman, 2007: Dynamic radiative-convective equilibria using GCM column physics. J. Atmos. Sci., 64, 228-238.
──, and M. Zhao, 2008: Horizontally homogeneous rotating radiative-convective equilibrium at GCM resolution. J. Atmos. Sci., 65, 2003-2013.
Houze, M. B., and W. C. Lee, 2009: Convective Contribution to the genesis of Hurricane Ophelia (2005). Mon. Wea. Rev., 137, 2778-2800.
Khairoutdinov, M. F., and K. A. Emanuel, 2010: Aggregation of convection and the regulation of tropical climate. In: Preprints. 29th Conference on hurricanes and tropical meteorology. American Meteorological Society, Tucson, AZ.
──, and ──, 2013: Rotating radiative-convective equilibrium simulated by a cloud-resolving model. J. Adv. Model. Earth Syst., 5, 816-825.
Manabe, S., and R. T. Wetherald, 1967: Thermal Equilibrium of Atmosphere with a Given Distribution of Relative Humidity. J. Atmos. Sci. 24, 241-259.
Montgomery, M. T., M. E. Nicholls, T. A. Cram, and A. B. Saunders, 2006: A Vortical Hot Tower Route to Tropical Cyclogenesis. J. Atmos. Sci. 63, 355-384.
Muller, C. J., and I. M. Held, 2012: Detailed investigation of the self-aggregation of convection in cloud resolving simutions. J. Atmos. Sci., 69, 2551-2565.
Nolan, D. S., E. D. Rappin, and K. A. Emanuel, 2007: Tropical cyclogenesis sensitivity to environmental parameters in radiative-convective equilibrium. Q. J. R. Meteorol. Soc. 133, 2085-2107.
Renno’, N. O., K. A. Emanuel, and P. H. Stone, 1994: Radiative-convective model with an explicit hydrological cycle 1. Formulation and sensitivity to model parameters. J. Geophys. Res. Atmos., 99, 14429-14440.
Wing, A. A., and T. W. Cronin, 2016: Self-aggregation of convection in long channel geometry. Q. J. R. Meteorol. Soc., 142, 1-15.
──, S. J. Camargo, and A. H. Sobel, 2016: Role of radiative-convective feedbacks in spontaneous tropical cyclogenesis in idealized numerical simulations. J. Atmos. Sci. 73: 2633-2642.
──, K. Emanuel, C. E. Holloway, and C. Muller, 2017: Convective Self-Aggregation in Numerical Simulations: A Review. Surv. Geophys. ISSN 1573-0956.
Wu, C. M., and A. Arakawa, 2011: Inclusion of surface topography into the vector vorticity equation model (VVM). J. Adv. Model Earth Syst., 3, M04002.
──, and A. Arakawa, 2014: A unified representation of deep moist convection in numerical modeling of the atmosphere. Part II. J. Atmos. Sci., 71, 2089-2103.
──, M. H. Lo, W. T. Chen, and C. T. Lu, 2015: The impacts of heterogeneous land surface fluxes on the diurnal cycle precipitation: A framework for improving the GCM representation of land-atmosphere interactions. J. Geophys. Res. Atmos., 120, 3714-3727.
Zhou, W., I. M. Held, and S. T. Garner, 2014: Parameter study of tropical cyclones in rotating radiative-convective equilibrium with column physics and resolution of a 25-km GCM. J. Atmos. Sci. 71: 1058-1069.
──, 2015: Non-rotating and rotating radiative-convective equilibrium. PhD thesis, Atmospheric and Oceanic Sciences, Princeton University.