DOCSLIB.ORG

Downloaded 10/06/21 09:49 PM UTC 478 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 68

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Downloaded 10/06/21 09:49 PM UTC 478 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 68 MARCH 2011 F I E R R O A N D R E I S N E R 477 High-Resolution Simulation of the Electrification and Lightning of Hurricane Rita during the Period of Rapid Intensification ALEXANDRE O. FIERRO Earth and Environmental Sciences Division/Space and Remote Sensing Group, Los Alamos National Laboratory, Los Alamos, New Mexico JON M. REISNER Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (Manuscript received 31 August 2010, in final form 15 November 2010) ABSTRACT In this paper, a high-resolution simulation establishing relationships between lightning and eyewall con- vection during the rapid intensification phase of Rita will be highlighted. The simulation is an attempt to relate simulated lightning activity within strong convective events (CEs) found within the eyewall and general storm properties for a case from which high-fidelity lightning observations are available. Specifically, the analysis focuses on two electrically active eyewall CEs that had properties similar to events observed by the Los Alamos Sferic Array. The numerically simulated CEs were characterized by updraft speeds exceeding 10 m s21, a relatively more frequent flash rate confined in a layer between 10 and 14 km, and a propagation speed that was about 10 m s21 less than of the local azimuthal flow in the eyewall. Within an hour of the first CE, the simulated minimum surface pressure dropped by approximately 5 mb. Concurrent with the pulse of vertical motions was a large uptake in lightning activity. This modeled relationship between enhanced vertical motions, a noticeable pressure drop, and heightened lightning activity suggests the utility of using lightning to remotely diagnose future changes in intensity of some tropical cyclones. Furthermore, given that the model can relate lightning activity to latent heat release, this functional relationship, once validated against a derived field produced by dual-Doppler radar data, could be used in the future to initialize eyewall convection via the introduction of latent heat and/or water vapor into a hurricane model. 1. Introduction and background on hurricane making landfall, hurricanes1 undergo rapid intensifi- electrification cation (RI), which is defined as any hurricane showing a 30 kt (or more) increase in 10-m maximum sustained Tropical cyclones (TCs) are among the most destructive wind speed in a 24-h period or less (Kaplan and DeMaria natural forces on the earth and many coastal commu- 2003). nities worldwide are threatened yearly by these extreme Though many recent observational studies (e.g., events. Hence, it is vital to advance our knowledge on Molinari et al. 1994, 1999; Price et al. 2009) have revealed the internal and external dynamical processes governing that rapidly intensifying hurricanes occasionally produce their evolution and especially their intensity, which is abundant eyewall lightning activity, only one highly ide- currently poorly forecast (e.g., Davis et al. 2008). This alized study, Fierro et al. (2007, hereafter F07), so far knowledge becomes especially critical when, before focused on modeling hurricane electrification. This work improves upon F07 by simulating Hurricane Rita (2005), Corresponding author address: Alexandre O. Fierro, Cooper- a hurricane that produced frequent eyewall lightning ative Institute for Mesoscale Meteorological Studies, National Weather Center, Suite 2100, 120 David L. Boren Blvd., Norman, OK 73072. 1 The terms ‘‘hurricanes’’ and ‘‘tropical cyclones’’ will be used E-mail: afi[email protected] interchangeably throughout this paper. DOI: 10.1175/2010JAS3659.1 Ó 2011 American Meteorological Society Unauthenticated | Downloaded 10/06/21 09:49 PM UTC 478 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUME 68 (e.g., Hurricane Isabel 2003) were shown to produce little lightning in the eyewall (Molinari et al. 1999; Demetriades and Holle 2005). Price et al. (2009) analyzed the cloud-to- ground (CG) lightning flash rate of 56 tropical cyclones around the globe using the World Wide Lightning Loca- tion Network (WWLLN; Jacobson et al. 2006; Lay et al. 2007), with their study revealing a strong correlation be- tween hurricane intensification rate and CG lightning ac- tivity. Furthermore, Cecil and Zipser (1999) found that a temporal lag existed between the production of ice scat- tering signature (proportional to convective intensity and lightning production) and the TC intensifying. Therefore, FIG. 1. (left) Horizontal projection of narrow bipolar events they also argued that lightning activity could be used as a (NBEs) with the time of observation specified at the top. The flashes reliable forecast tool as any changes in lightning frequency were color coded in time for each event, where blue represents early in time and red represents later in time. The circle shows the esti- were likely associated with future changes in the intensity mated location and size of the eye of Rita based on NHC best-track of a given TC. data. (right) Corresponding evolution of the heights of the NBE Because electrical activity is relatively infrequent within discharges. (Figure adapted from F11 and used with permission.) the eyewall, lightning associated with the convective bursts are easily observed by detection networks such as activity during its intensification cycle and from which LASA. Eyewall updrafts are too weak in the mixed phase very good lightning observations are available from a region to allow sufficient production and lofting of grau- broad array of platforms (Shao et al. 2005; Squires and pel particles and supercooled water (Black 1984; Black Businger 2008; Solorzano et al. 2008; Fierro et al. 2011, and Hallett 1986) that are necessary for the generation of hereafter F11). By comparing the simulated lightning be- strong electric fields via the noninductive charging process havior with available three-dimensional lightning obser- (Takahashi 1978; Saunders et al. 1991; Saunders and Peck vations from the Los Alamos Sferic Array (LASA; F11), 1998, hereafter SP98). For example, Black et al. (1996) this work provides hypotheses on the evolution of the found that 70% of the eyewall vertical velocities from microphysical/convective state of the hurricane as its in- seven Atlantic hurricanes ranged between 22and2 m s21 tensity changes. In particular, the work of F11, which is the with only about 5% of vertical motions exceeding 5 m s21. first presenting three-dimensional flash data within a hur- Stronger and wider updrafts capable of producing no- ricane, shows that during the period of rapid intensifica- table lightning bursts, such as those reported in F11, are tion, Rita produced several episodic and isolated lightning rare, except in some hurricanes undergoing rapid inten- bursts that rotated around the eyewall at a speed within sification: for example, Black et al. (1994) reported up- 10% to that of the local azimuthal flow (see Fig. 1 for an draft (downdraft) speeds reaching 24 (219) m s21 in example of those events) and had a life time between 15 Hurricane Emily (1987) during its deepening phase. and 25 min. Other examples of deep convective updrafts within TC Besides F11, many studies reported that the occurrence undergoing RI are documented in Eastin et al. (2005a,b) of lightning bursts near the TC center was often associated for Hurricane Guillermo (1997) and in Guimond et al. with intensification of the system and that these episodic (2010) for Hurricane Dennis (2005). lightning bursts were associated with deep convection This modeling study builds upon the observational (e.g., Lyons et al. 1989; Black et al. 1993; Lyons and Keen work of F11 by relating modeled lightning to key prop- 1994; Simpson et al. 1998; Rodgers et al. 2000; Heymsfield erties of the eyewall convection with focus on convective et al. 2001). Consistent with this, Kelley et al. (2004) events (CEs) and attempts to address questions that could suggested that extremely deep eyewall clouds (most likely not be easily answered by the observations. In this work, to produce lightning) observed via the Tropical Rainfall a CE is defined as an isolated convective entity in the Measuring Mission (TRMM) satellite in the eyewall were eyewall characterized by the following: 1) an instanta- coincident with a 70% likelihood of storm intensification. neous updraft speed greater than 10 m s21 anywhere It is also well recognized that RI often relies on the oc- above the freezing level, 2) a minimum depth of the currence of small-scale hard-to-forecast convective bursts 7ms21 isosurface of 5 km, 3) minimum horizontal di- (e.g., Steranka et al. 1986; Rodgers et al. 1998, 2000; mensions of 10 km 3 10 km, and 4) a minimum lifetime Reasor et al. 2009; Guimond et al. 2010) in the eyewall of of 15 min. The questions to be addressed include the the hurricane. In contrast to hurricanes undergoing RI, following: how strong is the convection within the mod- strong mature hurricanes remaining in a quasi–steady state eled CEs? How frequent are these events? What is their Unauthenticated | Downloaded 10/06/21 09:49 PM UTC MARCH 2011 F I E R R O A N D R E I S N E R 479 microphysical and electrical structure and in turn how do Mansell et al. (2005), which was adapted from Ziegler et al. these structures differ from that of the bulk of the eyewall (1991). Lightning initiation/discharge in the model occurs convection? How much latent heat is being released whenever the ambient electric field exceeds the breakeven within the simulated CEs? Note that the latter question is (or fair weather) electric field threshold, which was as- important with regard to relating observed lightning sumed to decrease exponentially with height, as in Mansell withinCEstoaquantitythatcanbeusedtoinitializeCEs et al. (2002), with the electric field and space charge den- within a model. Furthermore, though at least 4 distinct sities being decreased by a constant value of 10% through CEs were observed by LASA during a 24-h period, this the column upon discharge.
Load more

Recommended publications
  • Florida Commission on Hurricane Loss Projection Methodology
    Florida Commission on Hurricane Loss Projection Methodology Hurricane Ike Professional Team Report 22000088 SSttaannddaarrddss EQECAT, Inc. On-Site Review April 13 – 15, 2009 Additional Verification Review June 2, 2009 EQECAT Professional Team Report April 13-15, 2009 & June 2, 2009 On April 13-15, 2009 the Professional Team visited on-site at EQECAT, Inc. in Oakland, California. The following individuals participated in the review: EQECAT Shawna S. Ackerman, FCAS, MAAA, Principal and Consulting Actuary – Pinnacle Actuarial Resources, Inc. Branimir Betov, M.S., Senior Software Engineer Justin Brolley, Ph.D., Hazards Modeler and Research Scientist Apoorv Dabral, Ph.D., Project Engineer Aarti Dinesh, Product Manager Mahmoud M. Khater, Ph.D., P.E., Senior Vice President, Chief Science and Technology Officer Omar Khemici, Ph.D., P.E., Director (Structural Engineering) Bob Konz, Structural Wind Engineer (via phone) John Mangano, Vice President, Meteorologist David F. Smith, Senior Vice President, Technology Development and Consulting Jie Zhou, Ph.D., Research Scientist Professional Team Jenni Evans, Ph.D., Meteorologist Paul Fishwick, Ph.D., Computer Scientist Mark Johnson, Ph.D., Statistician, Team Leader Marty Simons, ACAS, Actuary Masoud Zadeh, Ph.D., P.E., Structural Engineer Donna Sirmons, Staff The review began with introductions and an overview of the audit process. EQECAT began with a discussion of the following model change: • Probabilistic hurricane database regenerated to be consistent with HURDAT as of June 1, 2008, and to additionally include the 2008 hurricane season. During the course of the audit, a further change was identified relative to a sampling method (see revised response to G-1.5). The Professional Team was unable to verify Standards A-6 (Logical Relationship to Risk) and A-10 (Output Ranges).
    [Show full text]
  • Effects of a Warm Oceanic Feature on Hurricane Opal
    1366 MONTHLY WEATHER REVIEW VOLUME 128 Effects of a Warm Oceanic Feature on Hurricane Opal LYNN K. SHAY Division of Meteorology and Physical Oceanography, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida GUSTAVO J. GONI Physical Oceanography Division, National Oceanic and Atmospheric Administration, Atlantic Oceanographic and Meteorological Laboratories, Miami, Florida PETER G. BLACK Hurricane Research Division, National Oceanic and Atmospheric Administration, Atlantic Oceanographic and Meteorological Laboratories, Miami, Florida (Manuscript received 24 September 1998, in ®nal form 21 February 1999) ABSTRACT On 4 October 1995, Hurricane Opal deepened from 965 to 916 hPa in the Gulf of Mexico over a 14-h period upon encountering a warm core ring (WCR) in the ocean shed by the Loop Current during an upper-level atmospheric trough interaction. Based on historical hydrographic measurements placed within the context of a two-layer model and surface height anomalies (SHA) from the radar altimeter on the TOPEX mission, upper- layer thickness ®elds indicated the presence of two warm core rings during September and October 1995. As Hurricane Opal passed directly over one of these WCRs, the 1-min surface winds increased from 35 to more than 60 m s21, and the radius of maximum wind decreased from 40 to 25 km. Pre-Opal SHAs in the WCR exceeded 30 cm where the estimated depth of the 208C isotherm was located between 175 and 200 m. Subsequent to Opal's passage, this depth decreased approximately 50 m, which suggests upwelling underneath the storm track due to Ekman divergence. The maximum heat loss of approximately 24 Kcal cm22 relative to depth of the 268C isotherm was a factor of 6 times the threshold value required to sustain a hurricane.
    [Show full text]
  • BERNAL-THESIS-2020.Pdf (5.477Mb)
    BROWNWOOD: BAYTOWN’S MOST HISTORIC NEIGHBORHOOD by Laura Bernal A thesis submitted to the History Department, College of Liberal Arts and Social Sciences in partial fulfillment of the requirements for the degree of MASTER OF ARTS in History Chair of Committee: Dr. Monica Perales Committee Member: Dr. Mark Goldberg Committee Member: Dr. Kristin Wintersteen University of Houston May 2020 Copyright 2020, Laura Bernal “A land without ruins is a land without memories – a land without memories is a land without history.” -Father Abram Joseph Ryan, “A Land Without Ruins” iii ACKNOWLEDGMENTS First, and foremost, I want to thank God for guiding me on this journey. Thank you to my family for their unwavering support, especially to my parents and sisters. Thank you for listening to me every time I needed to work out an idea and for staying up late with me as I worked on this project. More importantly, thank you for accompanying me to the Baytown Nature Center hoping to find more house foundations. I am very grateful to the professors who helped me. Dr. Monica Perales, my advisor, thank you for your patience and your guidance as I worked on this project. Thank you to my defense committee, Dr. Kristin Wintersteen and Dr. Goldberg. Your advice helped make this my best work. Additionally, I would like to thank Dr. Debbie Harwell, who encouraged me to pursue this project, even when I doubted it its impact. Thank you to the friends and co-workers who listened to my opinions and encouraged me to not give up. Lastly, I would like to thank the people I interviewed.
    [Show full text]
  • Mariner's Guide for Hurricane Awareness
    Mariner’s Guide For Hurricane Awareness In The North Atlantic Basin Eric J. Holweg [email protected] Meteorologist Tropical Analysis and Forecast Branch Tropical Prediction Center National Weather Service National Oceanic and Atmospheric Administration August 2000 Internet Sites with Weather and Communications Information Of Interest To The Mariner NOAA home page: http://www.noaa.gov NWS home page: http://www.nws.noaa.gov NWS marine dissemination page: http://www.nws.noaa.gov/om/marine/home.htm NWS marine text products: http://www.nws.noaa.gov/om/marine/forecast.htm NWS radio facsmile/marine charts: http://weather.noaa.gov/fax/marine.shtml NWS publications: http://www.nws.noaa.gov/om/nwspub.htm NOAA Data Buoy Center: http://www.ndbc.noaa.gov NOAA Weather Radio: http://www.nws.noaa.gov/nwr National Ocean Service (NOS): http://co-ops.nos.noaa.gov/ NOS Tide data: http://tidesonline.nos.noaa.gov/ USCG Navigation Center: http://www.navcen.uscg.mil Tropical Prediction Center: http://www.nhc.noaa.gov/ High Seas Forecasts and Charts: http://www.nhc.noaa.gov/forecast.html Marine Prediction Center: http://www.mpc.ncep.noaa.gov SST & Gulfstream: http://www4.nlmoc.navy.mil/data/oceans/gulfstream.html Hurricane Preparedness & Tracks: http://www.fema.gov/fema/trop.htm Time Zone Conversions: http://tycho.usno.navy.mil/zones.html Table of Contents Introduction and Purpose ................................................................................................................... 1 Disclaimer ...........................................................................................................................................
    [Show full text]
  • Characteristics of Hurricane Lili's Intensity Changes Adele Marie Babin Louisiana State University and Agricultural and Mechanical College, [email protected]
    Louisiana State University LSU Digital Commons LSU Master's Theses Graduate School 2004 Characteristics of Hurricane Lili's intensity changes Adele Marie Babin Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_theses Part of the Physical Sciences and Mathematics Commons Recommended Citation Babin, Adele Marie, "Characteristics of Hurricane Lili's intensity changes" (2004). LSU Master's Theses. 498. https://digitalcommons.lsu.edu/gradschool_theses/498 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]. CHARACTERISTICS OF HURRICANE LILI’S INTENSITY CHANGES 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 Natural Sciences in The Interdepartmental Program in Natural Sciences by Adele Marie Babin B.S. Louisiana State University, 1995 December 2004 DEDICATION I dedicate this research first and foremost to my mother Jane Alice Head Babin who passed before its completion, but her encouragement and inspiration motivated me onward. I also wish to dedicate the manuscript to my immediate family members: Father- Alfred Mark Babin Sister- Christa Babin Marshall, and husband Robert Andrew Marshall Brother- Dane Mark Babin, and wife Rachel Gros Babin and Grandmother: Mabel Babin Clement. ii ACKNOWLEDGEMENTS I extend my deepest gratitude to Dr. S.A.
    [Show full text]
  • Florida Commission on Hurricane Loss Projection Methodology
    Florida Commission on Hurricane Loss Projection Methodology Professional Team Report 2019 Hurricane Standards Hurricane Matthew Hurricane Michael CoreLogic, Inc. Remote Review April 5 – 8, 2021 CL Professional Team Report April 5-8, 2021 On April 5-8, 2021, the Professional Team conducted a remote review of the CoreLogic, Inc. (CL), CoreLogic Florida Hurricane Model 2021a in platform Risk Quantification and Engineering™ Version 21. The following individuals participated in the remote review. CoreLogic Amin Ilia, Ph.D., Coastal Scientist and Engineer Branimir Betov, M.S., Director, Model Development Daniel Betten, Ph.D., Atmospheric Scientist Justin Brolley, Ph.D., Principal Research Scientist Annes Haseemkunju, Ph.D., Atmospheric Scientist Mahmoud Khater, Ph.D., P.E., Chief Science and Engineering Officer Howard Kunst, FCAS, MAAA, Actuary Ilyes Meftah, Research Scientist Sergey Pasternak, Software Architect David Smith, Senior Director, Model Development Amanuel Tecle, Ph.D., Research Scientist Professional Team Paul Fishwick, Ph.D., Computer and Information Scientist Tim Hall, Ph.D., Meteorologist Mark Johnson, Ph.D., Statistician, Team Leader Stu Mathewson, FCAS, MAAA, Actuary Masoud Zadeh, Ph.D., P.E., Structural Engineer Donna Sirmons, Staff Due to the COVID-19 pandemic and State Board of Administration travel restrictions, the Professional Team conducted the review remotely rather than on-site. The remote review followed the on-site review process as detailed in the Report of Activities and the remote review procedures adopted by
    [Show full text]
  • T'fl""I:. (Florida), ISSN 0749-0208
    Journal of Coastal Research 462-476 Fort Lauderdale, Florida Spring 1996 Mid-Texas Coastal Marsh Change (1939-1991) as Influenced by Lesser Snow Goose Herbivory Deborah L. Miller']', Fred E. Smeins[ and James W. Webb:j: tRangeland Ecology and tMarine Biology Department Management Department Texas A&M University­ Texas A&M University Galveston College Station, TX 77843, P.O. Box 1675 U.S.A. Galveston, TX 77553, U.S.A. ABSTRACT _ MILLER, D.L.; SME1NS. ~'.E., and WEBB, J.W., 1996. Mid-Texas coastal marsh change (1939-1991) as influenced by lesser snow goose herbivory. Journal of Coastal Research, 12(2),462- 476. Fort Lauderdale :~,t'fl""I:. (Florida), ISSN 0749-0208. ~. Emergent coastal marshes of the San Bernard National Wildlife Refuge (SBNWR), were evaluated from 1939 to 1991 using aerial photography and 8 geographic information system (GIS). Vegetated marsh was ~~ it' transformed to mudflats and open water in areas heavily utilized by wintering lesser snow geese (LSG). SB Unvegetated marsh increased from less than 41);1 in 19:19to 21 % in 1991. Rate of denudation increased ¥' after 1965 when LSG numbers of 300,000 in the 1950's increased to nearly 1,000,000by the 1970's. Over time, some mudflats have revegetated, while others have become deep, open-water areas. Extremes of inter- and intra-annual tide levels, surface water and interstitial soil water salinity, and precipitation were also experienced during this time period. Repeated and intense herbivory by LSG followed by frequent tidal inundation, high soil and water salinities and extended droughts results in vegetation loss and the potential for accelerated soil erosion.
    [Show full text]
  • Prehistorical
    The Chronological History of Harlingen, Texas1 Prehistorical Before there were animals and before there were people, there were the land and the nameless river. Together they would shape the topography of the Harlingen area. The Lower Rio Grande Valley (LRGV) is a basin. The basin is a comparatively flat plain with a gentle slope to the northeast away from the river, which would be called the Rio Bravo, the Rio Grande del Norte, and eventually the Rio Grande, and towards what was to be designated the Gulf of Mexico. The political entities which were to come to be, Cameron County and most of Willacy County, lie in the basin subdivision called the Rio Grande Delta. "The area occupied by the delta, both ancient and recent, was once a broad valley, up to 400 feet deep, which was eroded from the coastal plain by the Rio Grande. It has since been filled with materials brought down by the river from inland areas." The only natural drain in Cameron County is the Arroyo Colorado. Arroyo is the Spanish word meaning small stream. It flows along the only two exposed geologic formations. These are the Beaumont Formation of Pleistocene age and the overlying sediments of Holocene (Recent) age. Both geologic ages created material deposits related to the rising and falling of the sea during and after the last major advance of the continental glaciers in North America. All of the Holocene age deposits are less than 5,000 years old. South and east of Harlingen are the cutoff meanders, called resacas, of the Rio Grande.
    [Show full text]
  • Hurricane Climatology for the Atlantic and Gulf Coasts of the United States
    *id. lSffAq- NOAA Technical Report NWS 38 T oI Hurricane Climatology for the Atlantic and C Gulf Coasts of the United States Silver Spring, MD April 1987 Study completed under agreement EMW-84-E-1589 for FEDERAL EMERGENCY MANAGEMENT AGENCY U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Weather Service NOAA TECHNICAL REPORTS National Weather Service Series The National Weather Service (NWS) observes and measures atmospheric phenomena; develops and distrib utes forecasts of weather conditions and warnings of adverse weather; collects and disseminates weather information to meet the needs of the public and specialized users. The NWS develops the national meteorological service system and improves procedures, techniques, and dissemination for weather and hydrologic measurements, and forecasts. NWS series of NOAA Technical Reports is a continuation of the former series, ESSA Technical Report Weather Bureau (WB). Reports listed below are available from the National Technical Information Service, U.S. Depart ment of Commerce, Sills Bldg., 5285 Port Royal Road, Springfield, VA 22161. Prices vary. Order by accession number (given in parentheses). ESSA Technical Reports WB 1 Monthly Mean 100-, 50-, 30-, and 10-Millibar Charts January 1964 through December 1965 of the IQSY Period. Staff, Upper Air Branch, National Meteorological Center, February 1967, 7 p, 96 charts. (AD 651 101) WB 2 Weekly Synoptic Analyses, 5-, 2-, and 0.4-Mb Surfaces for 1964 (based on observations of the Meteorological Rocket Network during the IQSY). Staff, Upper Air Branch, National Meteorologi cal Center, April 1967, 16 p, 160 charts. (AD 652 696) WB 3 Weekly Synoptic Analyses, 5-, 2-, and 0.4-Mb Surfaces for 1965 (based on observations of the Meteorological Rocket Network during the IQSY).
    [Show full text]
  • The Kinematic Structure of a Hurricane with Sea Level Pressure Less Than 900 Mb
    JUNE 1999 DODGE ET AL. 987 The Kinematic Structure of a Hurricane with Sea Level Pressure Less Than 900 mb PETER DODGE,ROBERT W. B URPEE,* AND FRANK D. MARKS JR. Hurricane Research Division, AOML/NOAA, Miami, Florida (Manuscript received 7 January 1998, in ®nal form 18 June 1998) ABSTRACT A National Oceanic and Atmospheric Administration aircraft recorded the ®rst Doppler radar data in a tropical cyclone with a minimum sea level pressure (MSLP) ,900 mb during a reconnaissance mission in Hurricane Gilbert on 14 September 1988, when its MSLP was ;895 mb. A previous mission had found an MSLP of 888 mb, making Gilbert the most intense tropical cyclone yet observed in the Atlantic basin. Radar re¯ectivity identi®ed the hurricane eye, inner and outer eyewalls, a stratiform region between the eyewalls, and an area outside the outer eyewall that contained a few rainbands but that had mostly stratiform rain. Pseudo±dual Doppler analyses depict the three-dimensional kinematic structure of the inner eyewall and a portion of the outer eyewall. The vertical pro®les of tangential wind and re¯ectivity maxima in the inner eyewall are more erect than in weaker storms, and winds .50 m s21 extended to 12 km, higher than has been reported in previous hurricanes. The inner eyewall contained weak in¯ow throughout most of its depth. In contrast, the portion of the outer eyewall described here had shallow in¯ow and a broad region of out¯ow. The stratiform region between the two eyewalls had lower re¯ectivities and was the only region where the vertically incident Doppler radar data seemed to show downward motion below the freezing level.
    [Show full text]
  • 'I Identify with Fighters': the South and Southern
    ‘I IDENTIFY WITH FIGHTERS’: THE SOUTH AND SOUTHERN IDENTITY IN LESBIAN FEMINIST ACTIVISM IN THE 1970S A Dissertation by HILLARY RAE ANDERSON Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, Albert Broussard Committee Members, Angela P. Hudson Julia Erin Wood Cynthia Bouton Joseph Jewell Head of Department, David Vaught May 2018 Major Subject: History Copyright 2018 Hillary Rae Anderson ABSTRACT This dissertation is a historical examination of the development of 1970s Southern lesbian feminism in the United States. It uses archival research, lesbian feminist periodicals and publications, and Southern lesbian feminist artistic production from the late 1960s to the early 1980s. The theory of intersectionality, Critical Race Theory, and elements of social movement theory informed the analysis. The timing of the 1970s brought together a particular political climate that nurtured Southern lesbian feminism. The 1970s were after major legislative victories in the civil rights movement, during a period of growth for American feminism when feminist and lesbian feminist print culture were at their height, and the decade was after the gay rights movement became militant, but before the AIDS crisis of the 1980s. This dissertation argues that Southern lesbian feminism’s development in the 1970s made the American South a new site for political agitation among self-identified lesbians; it proved the importance of Southernness – Southern identity – in lesbian feminist praxis. Southern culture shaped and tied together social constructions of race, gender, and sexuality, which caused Southern lesbian feminists to adopt a revolutionary political philosophy that uniquely combined elements of Black Power, radical feminism, and gay liberation, seeking to end multiple oppressions by transforming society.
    [Show full text]
  • Natural Hazards, Second Edition
    This page intentionally left blank NATURAL HAZARDS Natural hazards afflict all corners of the Earth; often unexpected, seemingly unavoidable and frequently catastrophic in their impact. This revised edition is a comprehensive, inter-disciplinary treatment of the full range of natural hazards. Accessible, readable and well supported by over 150 maps, diagrams and photographs, it is a standard text for students and an invaluable guide for professionals in the field. Clearly and concisely, the author describes and explains how hazards occur, examines prediction methods, considers recent and historical hazard events and explores the social impact of such disasters. This revised edition makes good use of the wealth of recent research into climate change and its effects. Edward Bryant is Associate Dean of Science at Wollongong University in Australia. Among his other publications is Tsunami: The Underrated Hazard (Cambridge University Press, 2001). He has particular interest in climatic change and coastal evolution. Praise for the First Edition: ‘Professor Bryant’s heroic compilation is an excellent guide.’ Scientific American NATURAL SECOND EDITION HAZARDS EDWARD BRYANT Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo Cambridge University Press The Edinburgh Building, Cambridge , UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521537438 © Edward Bryant 2005 This book is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published in print format 2005 - ---- eBook (EBL) - --- eBook (EBL) - ---- paperback - --- paperback Cambridge University Press has no responsibility for the persistence or accuracy of s for external or third-party internet websites referred to in this book, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.
    [Show full text]