DOCSLIB.ORG

Modélisation Mésoéchelle Des Cyclones Tropicaux Dans Le Sud-Ouest De L’Océan Indien Avec Méso-NH

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Modélisation Mésoéchelle Des Cyclones Tropicaux Dans Le Sud-Ouest De L’Océan Indien Avec Méso-NH UNIVERSITE DE LA REUNION Laboratoire de l’Atmosphère et des Cyclones – UMR 8105 Modélisation mésoéchelle des cyclones tropicaux dans le Sud-Ouest de l’Océan Indien avec Méso-NH. Cas d’étude DINA. par Samuel Jolivet tel-00462517, version 1 - 10 Mar 2010 en vue de l’obtention du grade de Docteur de l’Université de La Réunion (spécialité Physique de l’Atmosphère) Soutenue le 15 juillet 2008 Directeur de Thèse : M. Fabrice Chane-Ming (MCF HDR, Université de La Réunion) Composition du jury : Rapporteurs : M. Jean-Philippe Duvel (Directeur de recherche CNRS) M. Frank Roux (Professeur, Université Toulouse III) Examinateurs : M. Robert Delmas (Directeur de recherche CNRS) M. Matthieu Plu (Ingénieurs des Ponts et Chaussées, LACy, Météo-France) tel-00462517, version 1 - 10 Mar 2010 tel-00462517, version 1 - 10 Mar 2010 Remerciements Avant tout je tiens à remercier mon directeur de thèse Fabrice Chane-Ming pour m’avoir permis de mener ce projet à terme sous sa direction. La route fut longue mais terriblement intéressante à ses côtés. Merci de m’avoir donné la chance de réaliser ce rêve, rien n’aurait été possible autrement. Je remercie aussi les membres du jury d’avoir accepté de juger mon travail et d’avoir accepté d’assister à ma soutenance en cette période de vacances ! Plus particulièrement je suis très reconnaissant à Frank Roux d’avoir traversé l’équateur spécialement pour ma soutenance ! Je tiens à remercier Serge Baldy et Robert Delmas de m’avoir accueilli au sein du Laboratoire de l’Atmosphère et des Cyclones de l’Université de La Réunion anciennement Laboratoire de Physique de l’Atmosphère. De même je remercie Gérard Therry de m’avoir accueilli dans les locaux de Météo-France alors même que la Cellule de Recherche Cyclone ne faisait pas partie du LACy. Merci également à Samuel Westrelin pour m’avoir véritablement considéré comme un membre à part entière de la CRC. tel-00462517, version 1 - 10 Mar 2010 Je remercie La Région Réunion pour avoir financé ma thèse, et plus généralement de soutenir et de croire en la jeunesse Réunionnaise ! Je tiens à remercier spécialement Frank Roux pour tout ce qu’il aura pu représenter pendant cette thèse : un co-auteur, un collaborateur, un mentor et plus encore ! Merci de m’avoir accompagné dans cette aventure scientifique cyclonique. Un ENORME merci à David Barbary pour m’avoir formé à cette fabuleuse machine qu’est Méso-NH. Sans lui je serais encore en train d’essayer de faire tourner des cas tests … Merci pour sa disponibilité et sa continuelle bonne humeur. Je n’oublie pas toutes les personnes du LACy et de l’Université qui m’ont permis de travailler dans de très bonnes conditions et surtout dans une constante bonne humeur : Jean Marc, Françoise, Joyce, Monique, Céline, Lolita, France-Anne, Béa, Gaëlle, Pétronille, le M2 Géosphère, Rémy, Ghislain et tous les autres. Une spéciale dédicace à mes colocataires du 3ème Dr Denis, Guillaume, Dr Vidya, et Dorothée. « Un esprit sain dans un corps sain. » Une petite pensée pour le Sainte-Marie Volley Ball club et à mes coéquipiers. Merci pour tous ces moments sportifs de transpiration ! Un énorme bisou doux à tous les Moniteurs 2004, tous les Doctorants de la promo « Dos d’Ane » et les autres, les membres de la DJST, et tous ceux qui de près ou de loin ont contribué à la mise en place d’un environnement favorable à l’aboutissement de cette thèse : Safia, Audrey, Fred, Aline, Lo, Ruth, Seb, Julie MC, Hanna, Jennifer, Delphine, Dan, Eve, Alex, Gé, Nini, Aurélie, Lilian, Tony, Teddy, Gio, Gilles, Cédric, Pinchok, Nahouda, Chou, Nours, Chinois, Olivier, Fred Mad, Sygrid et j’en oublie sûrement … Une petite pensée pour toutes les personnes avec qui j’ai partagé mon repas favori, le Steak- Haricots Verts ! tel-00462517, version 1 - 10 Mar 2010 Merci à Tonton Serge et Tatie Marie Claude pour m’avoir procuré un havre de paix et de tranquillité pour ma rédaction. Je remercie aussi mon frère qui a toujours été là pour moi, malgré la distance, et qui m’a accompagné dans cette longue et grande aventure. Enfin j’aimerais dédicacer ce travail à mes parents, car ce sont eux qui m’ont inculqué le goût du travail! Ils m’ont donné l’envie et la force de réussir. Je les remercie aussi pour m’avoir soutenu et pour avoir cru en moi pendant toutes ces longues années d’étude ! MERCI ! tel-00462517, version 1 - 10 Mar 2010 Résumé Les cyclones tropicaux sont des phénomènes météorologiques hors normes qui participent efficacement à l’équilibre énergétique du système Terre. Ils redistribuent en effet l’excédent énergétique des océans tropicaux vers les régions du globe les plus froides. Ils peuvent malheureusement causer des dégâts considérables et entraîner de véritables tragédies quand ils approchent des pays des régions tropicales, comme celle du Myanmar avec le passage de NARGIS en Mai 2008. L’interaction de ces systèmes avec le relief environnant est reconnue pour influencer la trajectoire mais aussi l’intensité comme par exemple l’île de Taiwan qui interagit fortement avec les typhons passant à proximité du fait d’un relief important. Des cas de modifications de trajectoires, comme des déviations soudaines à l’approche de l’île ou encore des boucles se créant à proximité de l’île en l’absence de flux directeur, ont été observés aux abords de La Réunion. Ce travail de thèse porte sur l’étude de l’interaction entre l’île et le cyclone DINA qui avait bénéficié pour la première fois d’une couverture radar Doppler lors de son passage en Janvier 2002. Des simulations hautes résolutions ont été menées avec le modèle Méso-NH. Il a été montré que la présence de l’île induit une tendance générale à la stabilisation de la circulation cyclonique naturelle en relation avec un affaiblissement du système. Il a aussi été montré que la circulation des vents et la localisation des précipitations sur l’île en cas cyclonique sont entièrement définies par la topographie. De plus une étude approfondie a montré que l’évolution de la structure du mur de l’oeil en tel-00462517, version 1 - 10 Mar 2010 interaction avec le relief découlait de perturbations de l’anneau cyclonique de PV par des bandes de PV anticyclonique générées par l’île. L’étude d’autres types de cyclone (intensité, passage direct) pourrait permettre de valider et d’approfondir les résultats obtenus sur le forçage orographique de l’île. Mots clés : cyclone tropical, simulation haute résolution, forçage orographique, relief, précipitations. Abstract Tropical cyclones are amazing meteorological phenomena which contribute to equilibrate the energy budget of the Earth. Indeed they play an important role in exporting ocean energy from tropical regions to polar ones. Sometimes they can be unfortunately very dangerous inducing very strong damages and killing hundred thousands of people such as the landfall of NARGIS in May 2008 in Myanmar. Track and intensity of these systems are known to be influenced by the topography such as the case of Taiwan. Tracks modifications such as deviations and circular tracks occurring without any steering current have been already observed near Réunion island. This thesis work focuses on the interaction between the island and TC DINA (2002) which was also analysed by a Doppler radar. High resolution modeling have been run using Méso-NH model. The presence of the island is observed to stabilize the cyclonic circulation by damping the natural cyclonic circulation and so the intensity of the vortex. It was also shown that the local circulation of wind and the rainfall distribution are strongly controlled by the topography. Moreover an analysis of eyewall structure evolution has shown that the interaction with the island produced anticyclonic PV bands generated over the island which disturb the annular PV pattern. The study of different cyclones in term of intensity or with a closer track could help in defining better the orographic forcing of the island. Keywords: tropical cyclone, high resolution simulation, orographic forcing, tel-00462517, version 1 - 10 Mar 2010 precipitation. Remarques Préliminaires Cette thèse est publiée en format PDF. Des signets vous permettent de naviguer et de revenir au début, à la table des matières et aux listes de figures et tableaux. Ces trois derniers éléments étant eux même dynamiques. tel-00462517, version 1 - 10 Mar 2010 Table des matières Introduction 1 Première partie : Les cyclones tropicaux 5 Chapitre 1 : Généralités 7 1.1 Les cyclones tropicaux 8 1.1.1 Définitions et climatologie 8 1.1.2 Les mécanismes de la cyclogénèse et de 14 l’intensification 1.1.3 Structure d’un cyclone à maturité 20 tel-00462517, version 1 - 10 Mar 2010 1.2 Cas du Bassin Sud Ouest de l’Océan Indien 31 1.2.1 Climatologie 33 1.2.2 Les cyclones historiques et la saison 33 cyclonique 2001/2002 Chapitre 2 : Le cyclone tropical intense DINA 39 2.1 Un cyclone mémorable à La Réunion 40 vii Table des matières 2.1.1 Récit d’un phénomène marquant 40 2.1.2 Bilan météorologique 43 2.1.3 Bilan non météorologique 48 2.2 Un cyclone sous surveillance 51 2.2.1 Les différents types de données 51 2.2.2 Analyse des données Doppler par la 52 méthode GB-EVTD Deuxième partie : Modélisation du cyclone DINA : Principes et 57 méthodologies Chapitre 3 : La modélisation 59 3.1 La modélisation des cyclones 60 3.1.1 Les modèles statistiques 60 tel-00462517, version 1 - 10 Mar 2010 3.1.2 Les modèles globaux 61 3.1.3 Les modèles à aire limitée 62 3.1.4 Les contraintes 63 3.2 La modélisation méso-échelle 66 3.2.1 L’historique 66 3.2.2 L’influence du relief 69 viii 3.2.3 La modélisation haute résolution 72 Chapitre 4 :
Load more

Recommended publications
  • L'île De La Réunion Sous L'œil Du Cyclone Au Xxème Siècle. Histoire
    L’île de La Réunion sous l’œil du cyclone au XXème siècle. Histoire, société et catastrophe naturelle Isabelle Mayer Jouanjean To cite this version: Isabelle Mayer Jouanjean. L’île de La Réunion sous l’œil du cyclone au XXème siècle. Histoire, société et catastrophe naturelle. Histoire. Université de la Réunion, 2011. Français. NNT : 2011LARE0030. tel-01187527v2 HAL Id: tel-01187527 https://tel.archives-ouvertes.fr/tel-01187527v2 Submitted on 27 Aug 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. UNIVERSITE DE LA REUNION FACULTE DES LETTRES ET SCIENCES HUMAINES L’île de La Réunion sous l’œil du cyclone au XXème siècle. Histoire, société et catastrophe naturelle. TOME I Thèse de doctorat en Histoire contemporaine présentée par Isabelle MAYER JOUANJEAN Sous la direction du Professeur Yvan COMBEAU Le jury : -Pascal Acot, C.R.H. C.N.R.S., H.D.R., Université de Paris I – Panthéon Sorbonne ; C.N.R.S. -Yvan Combeau, Professeur d’Histoire contemporaine, Université de La Réunion -René Favier, Professeur d’Histoire moderne, Université Pierre Mendès France – Grenoble II -Claude Prudhomme, Professeur d’Histoire contemporaine, Université Lumière - Lyon II -Claude Wanquet, Professeur d’Histoire moderne émérite, Université de La Réunion Soutenance - 23 novembre 2011 « Les effets destructeurs de ces perturbations de saison chaude, dont la fréquence maximale est constatée en février, sont bien connus, tant sur l’habitat que sur les équipements collectifs ou les cultures.
    [Show full text]
  • Preparatory Survey Report on the Mauritius Meteorological Services Project in the Republic of Mauritius
    Mauritius Meteorological Services The Republic of Mauritius PREPARATORY SURVEY REPORT ON THE MAURITIUS METEOROLOGICAL SERVICES PROJECT IN THE REPUBLIC OF MAURITIUS November 2012 JAPAN INTERNATIONAL COOPERATION AGENCY JAPAN WEATHER ASSOCIATION INTERNATIONAL METEOROLOGICAL CONSULTANT INC. GE JR 12-143 Summary Summary Mauritius, a country consisting of small islands, is located in the cyclone-prone area of the Southwest Indian Ocean and is often affected by natural disasters such as heavy storms, tidal waves and floods caused by tropical cyclones, landslides and so on. Recently, climate change caused by global warming has posed a serious problem for Mauritius as it is predicted to have significant negative impacts on small island nations which are particularly vulnerable to a change in the natural environment. In addition, it is said that climate change has a potential to become the greatest threat to the sustainability of the very foundations of human survival. Thus, it is a significant global issue which developed and developing countries alike must deal with in mutually beneficial cooperation. In line with increasing global concerns on the intensification of disasters caused by climate change, the establishment of effective countermeasures against disasters such as severe storms, storm surges, and floods caused by tropical cyclones, rising sea level, tsunami, etc. has been an urgent task in Mauritius as well as in other countries in the Southwest Indian Ocean. In order for Mauritius to contribute to the alleviation of natural disasters in the Southwest Indian Ocean, the following are required and strongly desired: 1) An efficient meteorological observation system; and, 2) An Exchange of meteorological observation data and information about cyclones with neighboring countries in the Southwest Indian Ocean on a timely basis.
    [Show full text]
  • Eastern North Pacific Hurricane Season of 1997
    2440 MONTHLY WEATHER REVIEW VOLUME 127 Eastern North Paci®c Hurricane Season of 1997 MILES B. LAWRENCE Tropical Prediction Center, National Weather Service, National Oceanic and Atmospheric Administration, Miami, Florida (Manuscript received 15 June 1998, in ®nal form 20 October 1998) ABSTRACT The hurricane season of the eastern North Paci®c basin is summarized and individual tropical cyclones are described. The number of tropical cyclones was near normal. Hurricane Pauline's rainfall ¯ooding killed more than 200 people in the Acapulco, Mexico, area. Linda became the strongest hurricane on record in this basin with 160-kt 1-min winds. 1. Introduction anomaly. Whitney and Hobgood (1997) show by strat- Tropical cyclone activity was near normal in the east- i®cation that there is little difference in the frequency of eastern Paci®c tropical cyclones during El NinÄo years ern North Paci®c basin (east of 1408W). Seventeen trop- ical cyclones reached at least tropical storm strength and during non-El NinÄo years. However, they did ®nd a relation between SSTs near tropical cyclones and the ($34 kt) (1 kt 5 1nmih21 5 1852/3600 or 0.514 444 maximum intensity attained by tropical cyclones. This ms21) and nine of these reached hurricane force ($64 kt). The long-term (1966±96) averages are 15.7 tropical suggests that the slightly above-normal SSTs near this storms and 8.7 hurricanes. Table 1 lists the names, dates, year's tracks contributed to the seven hurricanes reach- maximum 1-min surface wind speed, minimum central ing 100 kt or more. pressure, and deaths, if any, of the 1997 tropical storms In addition to the infrequent conventional surface, and hurricanes, and Figs.
    [Show full text]
  • The Other Migrants Preparing for Change
    THE OTHER MIGRANTS PREPARING FOR CHANGE ENVIRONMENTAL CHANGES AND MIGRATION IN THE REPUBLIC OF MAURITIUS AN ASSESSMENT REPORT International Organization for Migration (IOM) 17 route des Morillons CH-1211 Geneva 19, Switzerland Tel: +41 22 717 9111 • Fax: +41 22 798 6150 E-mail: [email protected] • Internet: http://www.iom.int The opinions expressed in the report are those of the authors and do not necessarily reflect the views of the International Organization for Migration (IOM). The designations employed and the presentation of material throughout the report do not imply the expression of any opinion whatsoever on the part of IOM concerning the legal status of any country, territory, city or area, or of its authorities, or concerning its frontiers or boundaries. IOM is committed to the principle that humane and orderly migration benefits migrants and society. As an intergovernmental organization, IOM acts with its partners in the international community to: assist in meeting the operational challenges of migration; advance understanding of migration issues; encourage social and economic development through migration; and uphold the human dignity and well-being of migrants. Publisher: International Organization for Migration 17 route des Morillons 1211 Geneva 19 Switzerland Tel.: +41 22 717 91 11 Fax: +41 22 798 61 50 E-mail: [email protected] Internet: http://www.iom.int _____________________________________________________ © 2011 International Organization for Migration (IOM) _____________________________________________________ All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise without the prior written permission of the publisher.
    [Show full text]
  • Predictability of Explosive Cyclogenesis Over the Northwestern Pacific Region Using Ensemble Reanalysis
    NOVEMBER 2013 K U W A N O - Y O S H I D A A N D E N O M O T O 3769 Predictability of Explosive Cyclogenesis over the Northwestern Pacific Region Using Ensemble Reanalysis AKIRA KUWANO-YOSHIDA Earth Simulator Center, Japan Agency for Marine-Earth Science and Technology, Yokohama, Kanagawa, Japan TAKESHI ENOMOTO Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto, Japan (Manuscript received 1 June 2012, in final form 24 May 2013) ABSTRACT The predictability of explosive cyclones over the northwestern Pacific region is investigated using an en- semble reanalysis dataset. Explosive cyclones are categorized into two types according to whether the region of the most rapid development is in the Sea of Okhotsk or Sea of Japan (OJ) or in the northwestern Pacific Ocean (PO). Cyclone-relative composite analyses are performed for analysis increments (the differences between the analysis and the 6-h forecast) and ensemble spreads (the standard deviations of ensemble members of the analysis or first guess) at the time of the maximum deepening rate. The increment composite shows that the OJ explosive cyclone center is forecast too far north compared to the analyzed center, whereas the PO explosive cyclone is forecast shallower than the analyzed center. To understand the cause of these biases, a diagnosis of the increment using the Zwack–Okossi (Z-O) development equation is conducted. The results suggest that the increment characteristics of both the OJ and PO explosive cyclones are associated with the most important cyclone development mechanisms. The OJ explosive cyclone forecast error is related to a deeper upper trough, whereas the PO explosive cyclone error is related to weaker latent heat release in the model.
    [Show full text]
  • Climatology, Variability, and Return Periods of Tropical Cyclone Strikes in the Northeastern and Central Pacific Ab Sins Nicholas S
    Louisiana State University LSU Digital Commons LSU Master's Theses Graduate School March 2019 Climatology, Variability, and Return Periods of Tropical Cyclone Strikes in the Northeastern and Central Pacific aB sins Nicholas S. Grondin Louisiana State University, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_theses Part of the Climate Commons, Meteorology Commons, and the Physical and Environmental Geography Commons Recommended Citation Grondin, Nicholas S., "Climatology, Variability, and Return Periods of Tropical Cyclone Strikes in the Northeastern and Central Pacific asinB s" (2019). LSU Master's Theses. 4864. https://digitalcommons.lsu.edu/gradschool_theses/4864 This Thesis is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Master's Theses by an authorized graduate school editor of LSU Digital Commons. For more information, please contact [email protected]. CLIMATOLOGY, VARIABILITY, AND RETURN PERIODS OF TROPICAL CYCLONE STRIKES IN THE NORTHEASTERN AND CENTRAL PACIFIC BASINS A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Science in The Department of Geography and Anthropology by Nicholas S. Grondin B.S. Meteorology, University of South Alabama, 2016 May 2019 Dedication This thesis is dedicated to my family, especially mom, Mim and Pop, for their love and encouragement every step of the way. This thesis is dedicated to my friends and fraternity brothers, especially Dillon, Sarah, Clay, and Courtney, for their friendship and support. This thesis is dedicated to all of my teachers and college professors, especially Mrs.
    [Show full text]
  • HOULREU - Quantification De La Houle Centennale De Référence Sur Les Façades Littorales De La Réunion
    HOULREU - Quantification de la houle centennale de référence sur les façades littorales de La Réunion BRGM/RP-57829-FR Décembre 2009 HOULREU - Quantification de la houle centennale de référence sur les façades littorales de La Réunion BRGM/RP-57829-FR Décembre 2009 Étude réalisée dans le cadre des projets de Service public du BRGM 2009 09RISY01 Pedreros R., Lecacheux S., Le Cozannet G., Blangy A. et De la Torre Y. avec la collaboration de Quetelard H. (Météo-France) Vérificateur : Approbateur : Nom : C. OLIVEROS Nom : J.L. NEDELLEC Date : Date : Signature : Signature : En l’absence de signature, notamment pour les rapports diffusés en version numérique, l’original signé est disponible aux Archives du BRGM. Le système de management de la qualité du BRGM est certifié AFAQ ISO 9001:2000. Mots clés : Houle cyclonique, houle australe, alizés, Réunion, modélisation numérique, houle centennale En bibliographie, ce rapport sera cité de la façon suivante : Pedreros R., Lecacheux S., Le Cozannet G., Blangy A. et De la Torre Y., (2009). « HOULREU » Quantification de la houle centennale de référence sur les façades littorales de La Réunion. BRGM/RP -57829-FR, 119 p., 93 fig., 14 tab. © BRGM, 2010, ce document ne peut être reproduit en totalité ou en partie sans l’autorisation expresse du BRGM. HOULREU – Quantification de la houle centennale Synthèse Le cyclone GAMEDE et les houles de tempête de mai 2007 ont rappelé la forte vulnérabilité des littoraux de La Réunion aux aléas côtiers (érosion, submersion). Or, il n’existe pas de document de prévention (PPR) intégrant les risques côtiers. Dans ce contexte, la DDE souhaite mettre en place une démarche permettant la caractérisation et la cartographie des aléas côtiers sur le territoire réunionnais.
    [Show full text]
  • Explosive Cyclogenesis: a Global Climatology Comparing Multiple Reanalyses
    6468 JOURNAL OF CLIMATE VOLUME 23 Explosive Cyclogenesis: A Global Climatology Comparing Multiple Reanalyses JOHN T. ALLEN,ALEXANDRE B. PEZZA, AND MITCHELL T. BLACK The University of Melbourne, Melbourne, Victoria, Australia (Manuscript received 17 September 2009, in final form 23 August 2010) ABSTRACT A global climatology for rapid cyclone intensification has been produced from the second NCEP reanalysis (NCEP2), the 25-yr Japanese Reanalysis (JRA-25), and the ECMWF reanalyses over the period 1979–2008. An improved (combined) criterion for identifying explosive cyclones has been developed based on preexisting definitions, offering a more balanced, normalized climatological distribution. The combined definition was found to significantly alter the population of explosive cyclones, with a reduction in ‘‘artificial’’ systems, which are found to compose 20% of the population determined by earlier definitions. Seasonally, winter was found to be the dominant formative period in both hemispheres, with a lower degree of interseasonal variability in the Southern Hemisphere (SH). Considered over the period 1979–2008, little change is observed in the frequency of systems outside of natural interannual variability in either hemisphere. Significant statistical differences have been found between reanalyses in the SH, while in contrast the Northern Hemisphere (NH) was characterized by strong positive correlations between reanalyses in almost all examined cases. Spatially, explosive cyclones are distributed into several distinct regions, with two regions in the northwest Pacific and the North Atlantic in the NH and three main regions in the SH. High-resolution and modern reanalysis data were also found to increase the climatology population of rapidly intensifying systems. This indicates that the reanalyses have apparently undergone increasing improvements in consistency over time, particularly in the SH.
    [Show full text]
  • The Effects of Diabatic Heating on Upper
    THE EFFECTS OF DIABATIC HEATING ON UPPER- TROPOSPHERIC ANTICYCLOGENESIS by Ross A. Lazear A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Atmospheric and Oceanic Sciences) at the UNIVERSITY OF WISCONSIN - MADISON 2007 i Abstract The role of diabatic heating in the development and maintenance of persistent, upper- tropospheric, large-scale anticyclonic anomalies in the subtropics (subtropical gyres) and middle latitudes (blocking highs) is investigated from the perspective of potential vorticity (PV) non-conservation. The low PV within blocking anticyclones is related to condensational heating within strengthening upstream synoptic-scale systems. Additionally, the associated convective outflow from tropical cyclones (TCs) is shown to build upper- tropospheric, subtropical anticyclones. Not only do both of these large-scale flow phenomena have an impact on the structure and dynamics of neighboring weather systems, and consequently the day-to-day weather, the very persistence of these anticyclones means that they have a profound influence on the seasonal climate of the regions in which they exist. A blocking index based on the meridional reversal of potential temperature on the dynamic tropopause is used to identify cases of wintertime blocking in the North Atlantic from 2000-2007. Two specific cases of blocking are analyzed, one event from February 1983, and another identified using the index, from January 2007. Parallel numerical simulations of these blocking events, differing only in one simulation’s neglect of the effects of latent heating of condensation (a “fake dry” run), illustrate the importance of latent heating in the amplification and wave-breaking of both blocking events.
    [Show full text]
  • Verification of a Storm Surge Modeling System for the New York City – Long Island Region
    Verification of a Storm Surge Modeling System for the New York City – Long Island Region A Thesis Presented By Thomas Di Liberto to The Graduate School in Partial Fulfillment of the Requirements for the Degree of Master of Science in Marine and Atmospheric Science Stony Brook University August 2009 Stony Brook University The Graduate School Thomas Di Liberto We, the thesis committee for the above candidate for the Master of Science degree, hereby recommend acceptance of this thesis. Dr. Brian A. Colle, Thesis Advisor Associate Professor School of Marine and Atmospheric Sciences Dr. Malcolm J. Bowman, Thesis Reader Professor School of Marine and Atmospheric Sciences Dr. Edmund K.M. Chang, Thesis Reader Associate Professor School of Marine and Atmospheric Sciences This thesis is accepted by the Graduate School Lawrence Martin Dean of the Graduate School ii Abstract of the Thesis Verification of a Storm Surge Modeling System for the New York City – Long Island Region by Thomas Di Liberto Master of Science in Marine and Atmospheric Science Stony Brook University 2009 Storm surge from tropical cyclones events nor‟ easters can cause significant flooding problems for the New York City (NYC) – Long Island region. However, there have been few studies evaluating the simulated water levels and storm surge during a landfalling hurricane event over NYC-Long Island as well as verifying real-time storm surge forecasting systems for NYC-Long Island over a cool season. Hurricane Gloria was simulated using the Weather Research and Forecasting (WRF) V2.1 model, in which different planetary boundary layer (PBL) and microphysics schemes were used to create an ensemble of hurricane landfalls over Long Island.
    [Show full text]
  • The San Diego Hurricane of 2 October 1858
    THE SAN DIEGO HURRICANE OF 2 OCTOBER 1858 BY MICHAEL CHENOWETH AND CHRISTOPHER LANDSEA The discovery of a hurricane that directly impacted San Diego, California, nearly 150 yr ago has implications for residents and risk managers in their planning for extreme events for the region. ropical cyclones forming in the eastern North 10 September 1976 in California and Arizona, and Pacific Ocean are occasional visitors to the Hurricane Nora in September 1997 in Arizona. Only Tsouthwestern United States. By the time these the 1939 tropical storm made a direct landfall in coastal systems travel far enough to the north to bring their California (Smith 1986), because the other three sys- associated moisture to the United States, the tropical tems entered the United States after first making land- cyclones have normally diminished below tropical fall in Mexico. storm strength over Mexico or over the colder waters The 1939 tropical storm caused $2 million in prop- of the California Current that flows southward along erty damage in California, mostly to shipping, shore the California coast. Rain, sometimes locally excessive, structures, power and communication lines, and crops. is frequently observed in many areas of the southwest- Ships in coastal waters of southern California reported ern United States when tropical cyclone remnants en- southeast winds between 34 and 47 kt (Hurd 1939). ter the region (Blake 1935; Smith 1986). However, no tropical cyclones are recorded or esti- Four tropical cyclones have managed to bring tropi- mated to have made landfall in the southwestern cal storm-force winds to the southwestern United United States as a hurricane, with maximum 1-min States during the twentieth century: a tropical storm surface (10 m) winds of at least 64 kt.
    [Show full text]
  • The Contribution of Eastern North Pacific Tropical Cyclones to The
    AUGUST 2009 C O R B O S I E R O E T A L . 2415 The Contribution of Eastern North Pacific Tropical Cyclones to the Rainfall Climatology of the Southwest United States KRISTEN L. CORBOSIERO Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, California MICHAEL J. DICKINSON Weather Predict Consulting, Inc., Narragansett, Rhode Island LANCE F. BOSART Department of Earth and Atmospheric Sciences, University at Albany, State University of New York, Albany, New York (Manuscript received 26 August 2008, in final form 6 March 2009) ABSTRACT Forty-six years of summer rainfall and tropical cyclone data are used to explore the role that eastern North Pacific tropical cyclones (TCs) play in the rainfall climatology of the summer monsoon over the southwestern United States. Thirty-five TCs and their remnants were found to bring significant rainfall to the region, representing less than 10% of the total number of TCs that formed within the basin. The month of September was the most common time for TC rainfall to occur in the monsoon region as midlatitude troughs become more likely to penetrate far enough south to interact with the TCs and steer them toward the north and east. On average, the contribution of TCs to the warm-season precipitation increased from east to west, accounting for less than 5% of the rainfall in New Mexico and increasing to more than 20% in southern California and northern Baja California, with individual storms accounting for as much as 95% of the summer rainfall. The distribution of rainfall for TC events over the southwest United States reveals three main categories: 1) a direct northward track from the eastern Pacific into southern California and Nevada, 2) a distinct swath northeastward from southwestern Arizona through northwestern New Mexico and into southwestern Col- orado, and 3) a broad area of precipitation over the southwest United States with embedded maxima tied to terrain features.
    [Show full text]