Statistical Analysis of Sub-Synoptic Meteorological Patterns
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Late Holocene Climate Variability in South- Central Chile: a Lacustrine Record of Southern Westerly Wind Dynamics
Late Holocene Climate Variability in South- Central Chile: a Lacustrine Record of Southern Westerly Wind Dynamics. Jonas Vandenberghe ACKNOWLEDGEMENTS First of all, I would like to thanks Prof. Dr. Marc De Batist for the support and supervision of my thesis and for providing this interesting subject as a master thesis project. He was always available for questions and added meaningful corrections and insights on more difficult topics. Special thanks goes to my advisor Willem Vandoorne for his endless support, corrections and answers to my questions in both the lab and during the writing of my thesis. Also I would like to thank other researchers at RCMG especially Maarten and Katrien for very useful explanations and discussions. I am very thankful for the help of all other personel who, directly or indirectly, contributed to this work. Prof. Dr. Eddy Keppens, Leen and Michael from the VUB for their efforts during the carbon and nitrogen isotopic analysis and Rieneke Gielens for her great help with the XRF core scanning at NIOZ. Finally I would like to thank my parents for their support and my girlfriend Celine for coping with me when I was under stress and for providing solutions to all kinds of problems. 1 SAMENVATTING In de laatste decennia was er een opmerkelijke stijging van onderzoek in klimaat reconstructies van de voorbije 1000 jaar. Deze reconstructies moeten een bijdrage leveren aan het begrijpen van de recente klimaatsveranderingen. Klimaatsreconstructies van het laatste millennium kunnen informatie geven over de significantie van deze stijgende trend, de oorzaak van de opwarming en de invloed ervan op andere omgeveingsmechanismes op Aarde. -
Downloaded 09/30/21 07:50 AM UTC 668 JOURNAL of the ATMOSPHERIC SCIENCES VOLUME 66
MARCH 2009 K U M J I A N A N D R Y Z H K O V 667 Storm-Relative Helicity Revealed from Polarimetric Radar Measurements MATTHEW R. KUMJIAN AND ALEXANDER V. RYZHKOV Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, and NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma (Manuscript received 14 April 2008, in final form 27 August 2008) ABSTRACT The dual-polarization radar variables are especially sensitive to the microphysical processes of melting and size sorting of precipitation particles. In deep convective storms, polarimetric measurements of such processes can provide information about the airflow in and around the storm that may be used to elucidate storm behavior and evolution. Size sorting mechanisms include differential sedimentation, vertical transport, strong rotation, and wind shear. In particular, winds that veer with increasing height typical of supercell environments cause size sorting that is manifested as an enhancement of differential reflectivity (ZDR) along the right or inflow edge of the forward-flank downdraft precipitation echo, which has been called the ZDR arc signature. In some cases, this shear profile can be augmented by the storm inflow. It is argued that the magnitude of this enhancement is related to the low-level storm-relative environmental helicity (SRH) in the storm inflow. To test this hypothesis, a simple numerical model is constructed that calculates trajectories for raindrops based on their individual sizes, which allows size sorting to occur. The modeling results indicate a strong positive correlation between the maximum ZDR in the arc signature and the low-level SRH, regardless of the initial drop size distribution aloft. -
Educator's Guide
Christenberry Planetarium Educator’s Guide ALABAMA SKIES Credit: Hubble Telescope INSIDE: www.samford.edu/departments/planetarium/ • Connections to Education Standards • Preparation Questions • Solar System Breakdown • Synopsis • Glossary of Terms • Classroom Activities 1 Table of Contents FOR THE EDUCATOR Connections to Education Standards…………………….………………….. 2 BEFORE THE SHOW Preparation Questions………………………………………………………… 3 Solar System Breakdown……………………………………………………… 4 AFTER THE SHOW Synopsis…………………………………………………………………………. 6 Classroom Activities……...………………………………………..………..…. 8 Glossary of Terms………………………………………………………………12 Online Resources……………………………………………………………….13 2 Connections to Education Standards Below you will find the national education content standards that we explore in our presentation: NATIONAL EDUCATION CONTENT STANDARDS GRADE CONTENT STANDARD All: Science as a human endeavor K – 4: Objects in the sky Changes in the earth and sky 5 – 8: Motion and forces Earth in the solar system 9 – 12: Motion and forces Interactions of energy and matter Credit: Andrew C. Freeman 3 Preparation Questions What is a Solar System? A solar system is a collection of the planets and their moons in orbit around a star (in our case, the sun). It also includes smaller bodies in the forms of asteroids, meteoroids, comets, and dwarf planets. What is a Galaxy? A system of billions or even trillions of stars along with planets, interstellar Credit: Andrew C. Freeman clouds of gas and dust, and dark matter all held together by gravitational What is the Milky Way? attraction. There are three kinds of galaxies: elliptical, spiral, and irregular. The Milky Way is a barred spiral galaxy that houses our solar system along with How Many Galaxies are There? 100-400 billion stars and at least the There are countless galaxies in the same number of planets. -
1 Orographic Effects on Supercell: Development and Structure
Orographic Effects on Supercell: Development and Structure, Intensity and Tracking Galen M. Smith1, Yuh-Lang Lin1,2,@, and Yevgenii Rastigejev1,3 1Department of Energy and Environmental Systems 2Department of Physics 3Department of Mathematics North Carolina A&T State University March 1, 2016 @Corresponding Author Address: Dr. Yuh-Lang Lin, 302H Gibbs Hall, EES, North Carolina A&T State University, 1601 E. Market St., Greensboro, NC 27411. Email: [email protected]. Web: http://mesolab.ncat.edu Abstract Orographic effects on tornadic supercell development, propagation, and structure are investigated using Cloud Model 1 (CM1) with idealized bell-shaped mountains of various heights and a homogeneous fluid flow with a single sounding. It is found that blocking effects are dominative compared to the terrain-induced environmental heterogeneity downwind of the mountain. The orographic effect shifted the track of the storm towards the the left of storm motion, particularly on the lee side of the mountain, when compared to the track in the case with no mountain. The terrain blocking effect also enhanced the supercells inflow, which was increased more than one hour before the storm approached the terrain peak. This allowed the central region of the storm to exhibit clouds with a greater density of hydrometeors than the control. Moreover, the enhanced inflow increased the areal extent of the supercells precipitation, which, in turn enhanced the cold pool outflow serving to enhance the storm’s updraft until becoming strong enough to undercut and weaken the storm considerably. Another aspect of the orographic effects is that down slope winds produced or enhanced low-level vertical vorticity directly under the updraft when the storm approached the mountain peak. -
An East Coast Winter Storm Climatology
882 JOURNAL OF CLIMATE VOLUME 14 An East Coast Winter Storm Climatology MATTHEW E. HIRSCH,ARTHUR T. D EGAETANO, AND STEPHEN J. COLUCCI Northeast Regional Climate Center, Cornell University, Ithaca, New York (Manuscript received 9 July 1999, in ®nal form 16 May 2000) ABSTRACT A climatology of East Coast winter storms (ECWS) was developed using an automated procedure. This routine was used along with the NCEP±NCAR reanalysis dataset (1948, 1951±97) to identify storms over the October± April winter season. An array of statistical analyses was used to empirically analyze the interannual variability of these cyclones. To be classi®ed as an ECWS, an area of low pressure was required to have a closed circulation, be located along the east coast of the United States (within the quadrilateral bounded at 458Nby658 and 708W and at 308Nby758 and 858W), show general movement from the south-southwest to the north-northeast, and contain winds greater than 10.3 m s21 (20 kt) for at least one time period (6 h). Storms meeting the above criteria were also required to have a closed circulation and be located within the quadrilateral during one additional 6-h period (not necessarily consecutive with the ®rst). On average, 12 ECWS occurred per season with a maximum in January. Signi®cant trends in storm frequency over the 46-yr period beginning in 1951 are not evident. However, a marginally signi®cant (a 5 0.10) increase in average storm minimum pressure is noted. Spectral analysis of the ECWS time series shows signi®cant cycles with periods of 2.3, 2.8, 3.4, 4.8, and 10.2 yr, which are in agreement with documented periodicities in joint Atlantic SST and sea level pressure data. -
A Sample AMS Latex File
East Coast Cool-weather Storms in the New York Metropolitan Region H. Salmun Hunter College of CUNY, New York, NY A. Molod University of Maryland Baltimore County, Baltimore, MD F. S. Buonaiuto Hunter College of CUNY, New York, NY K. Wisniewska Hunter College of CUNY, New York, NY K. C. Clarke Hunter College of CUNY, New York, NY Accepted for publication in Journal of Applied Meteorology and Climatology – June 2009 ____________________ Corresponding author address: Haydee Salmun, Hunter College of CUNY, 695 Park Avenue, New York, NY 10065. E-mail: [email protected] ABSTRACT New York coastal regions are frequently exposed to winter extratropical storm systems that exhibit a wide range of local impacts. Studies of these systems have either used localized water level or beach erosion data to identify and characterize the storms, or used meteorological conditions from reanalysis data to provide a general regional climatology of storms. The use of meteorological conditions to identify these storms allows an independent assessment of impacts on the coastal environment, and therefore can be used to predict the impacts. However, the intensity of these storms can exhibit substantial spatial variability that may not be captured by the relatively large scales of the studies using reanalysis data, and this may affect the localized assessment of storm impact on the coastal communities. A method that uses data from National Data Buoy Center (NDBC) stations in the New York metropolitan area to identify East Coast Cool-weather Storms (ECCSs) and characterize their climatology is presented. An assessment of the presence of storm conditions and a three level intensity scale was developed using surface pressure data as measured at the buoys. -
Universidade Federal De Pernambuco Centro De Ciências Exatas E Da
Universidade Federal de Pernambuco Centro de Ciˆencias Exatas e da Natureza Departamento de F´ısica P´os-gradua¸c˜ao em F´ısica VORTEX MOTION AROUND A CIRCULAR CYLINDER BOTH IN AN UNBOUNDED DOMAIN AND NEAR A PLANE BOUNDARY Marcel Nascimento de Moura DISSERTAC¸AO˜ DE MESTRADO Recife 17 de maio de 2012 Universidade Federal de Pernambuco Centro de Ciˆencias Exatas e da Natureza Departamento de F´ısica Marcel Nascimento de Moura VORTEX MOTION AROUND A CIRCULAR CYLINDER BOTH IN AN UNBOUNDED DOMAIN AND NEAR A PLANE BOUNDARY Trabalho apresentado ao Programa de P´os-gradua¸c˜aoem F´ısica do Departamento de F´ısica da Universidade Federal de Pernambuco como requisito parcial para obten¸c˜aodo grau de Mestre em F´ısica. Orientador: Giovani Lopes Vasconcelos Banca examinadora: Prof. Giovani Lopes Vasconcelos (Departamento de F´ısica - UFPE) Prof. Darren Gregory Crowdy (Department of Mathematics - Imperial College London) Prof. Cl´ecio Clemente de Souza Silva (Departamento de F´ısica - UFPE) Recife 17 de maio de 2012 Catalogação na fonte Bibliotecária Joana D’Arc L. Salvador, CRB 4-572 Moura, Marcel Nascimento de. Vortex motion around a circular cylinder both in an unbounded domain and near a plane boundary / Marcel Nascimento de Moura. – Recife: O Autor, 2012. xiv, 93 f.: fig. Orientador: Giovani Lopes Vasconcelos. Dissertação (Mestrado) - Universidade Federal de Pernambuco. CCEN. Física, 2012. Inclui bibliografia e apêndice. 1. Dinâmica dos fluidos. 2. Dinâmica de vórtices. 3. Sistemas hamiltonianos. I. Vasconcelos, Giovani (orientador). II. Título. -
Pulsing Inertial Oscillation, Supercell Storms, and Surface Mesonetwork Data
Pulsing inertial oscillation, supercell storms, and surface mesonetwork data R. C. COSTEN1 and L. J. MILLER2 1NASA Langley Research Center, Hampton, Virginia 23681-2199 USA 2National Center for Atmospheric Research,* Boulder, Colorado 80307-3000 USA Abstract. The pulsing inertial oscillation (PIO) model is a nonlinear, time-dependent, translating vortex solution of the inviscid, compressible fluid dynamic equations in the middle troposphere. The translation of this vortex during a pulse is strikingly similar to that of a supercell storm -- a rotating thunderstorm that can generate tornadoes and hail. Two studies were performed to test the hypothesis that some supercell storms are manifestations of a PIO pulse. The first study applied the model to an intense interior draft whose buoyancy was bounded by a temperature excess of ±12 K . The peak updraft speed achieved was 41.5 m s-1 and the peak Rossby number was 92.9. The study also pointed to an advanced concept for attaining higher values. The second study applied the PIO model to a supercell storm as a whole and succeeded in replicating its bulk properties, such as mesocyclonic circulation, net mass and moisture influxes, and time track. This study also identified a critical feature of the PIO model that could be tested against storm data: The average vertical draft is downward before the turn in the storm track and upward afterwards. In the conventional theory, the average vertical draft is upward from storm inception until dissipation. These differing draft predictions were compared with the best available data, which are surface mesonetwork data. These data were found to support the PIO model. -
First WSR-88D Documentation of an Anticyclonic Supercell with Anticyclonic Tornadoes: the Sunnyvale±Los Altos, California, Tornadoes of 4 May 1998
NOVEMBER 2001 PICTURE OF THE MONTH 2805 PICTURE OF THE MONTH First WSR-88D Documentation of an Anticyclonic Supercell with Anticyclonic Tornadoes: The Sunnyvale±Los Altos, California, Tornadoes of 4 May 1998 JOHN P. M ONTEVERDI San Francisco State University, San Francisco, California WARREN BLIER National Weather Service Forecast Of®ce, Monterey, California GREG STUMPF National Severe Storms Laboratory, and Cooperative Institute for Mesoscale Meteorology Studies, University of Oklahoma, Norman, Oklahoma WILFRED PI National Weather Service Forecast Of®ce, Monterey, California KARL ANDERSON Second Nature, Sunnyvale, California 16 August 2000 and 12 June 2001 ABSTRACT On 4 May 1998, a pair of tornadoes occurred in the San Francisco Bay Area in the cities of Sunnyvale (F2 on the Fujita scale) and Los Altos (F1). The parent thunderstorm was anticyclonically rotating and produced tornadoes that were documented photographically to be anticyclonic as well, making for an extremely rare event. The tornadic thunderstorm was one of several ``pulse type'' thunderstorms that developed on out¯ow boundaries on the left ¯ank of an earlier-occurring thunderstorm east of San Jose. Satellite imagery showed that the tomadic storm moved northwestward along a sea-breeze boundary and ahead of the out¯ow boundary associated with the prior thun- derstorms. The shear environment into which the storm propagated was characterized by a straight hodograph with some cyclonic curvature, and by shear and buoyancy pro®les that were favorable for anticyclonically rotating updrafts. Mesoanticyclones were detected in the Monterey (KMUX) radar data in association with each tornado by the National Severe Storm Laboratory's (NSSL) new Mesocyclone Detection Algorithm (MDA) making this the only documented case of a tornadic mesoanticyclone in the United States that has been captured with WSR- 88D level-II data. -
Anticyclonic Storm#. [Jour
420 Anticyclonic Storm#. [Jour. Frank. Inst.~ degrees of freedom, are introduced with respect to any of the co-ordi- nates, the energy will no longer be equally distribmed among all the. co-ordinates, but will be influenced by these constraints. This is what was found to take place in imperfect gases, where the inter- molecular attractions affect the components of the progressive motion,. but not the rotary components. In many points the results arrived at in this paper are in substantial accordance with those found by Boltzmann* in his important papers upon this subject ; but both he and Watson regard some of the experi-: mental values of x, and in particular all values less than 1"83, to be in contradiction to theory. So far as is known to the author, theinvesti- gation which he has here given to the question explains for the first time this contradiction which Watson (p. 39) regards as "the great. difficulty in the establishment of the kinetic theory of gases on th~ molecular hypothesis." CINCI.W~ATI, January 18, 1883. ANTICYCLONIC STORMS. By PUNY EARLE CHASE, LL.D. The science of Meteorology may, for many good reasons, be regarded[ as a peculiarly American science. William Ferrel's discussion of the motion of fluids and solids relative to the earth's surface, which was first published in the summer of 1856, placed the laws of cyclonism and anticyclonism on a solid mathematical basis, lie showed that, in the northern hemisphere, all moving bodies are constantly subjected~ in consequence of the earth's rotation, to a deflection towards the right hand. -
Table of Contents Topic: Velocity Interpretation
Table of Contents Topic: Velocity Interpretation Click to jump to lesson Lesson 1 Large-Scale Doppler Velocity Patterns Lesson 2 Storm-Scale Doppler Velocity Patterns Hi, my name is Jill Hardy and welcome to this Topic on Velocity Interpretation. This lesson will cover large-scale Doppler velocity patterns, while the next lesson will focus on storm-scale patterns. 1 Let’s start with a brief review. When interpreting velocity data, the radial velocities are displayed, which are not the true velocities. Also, the RPG dealiases velocities while the RDA performs range folding. These tasks are effective most of the time, but failures do occur, which can inhibit your ability to interpret velocity products. 3 There are three learning objectives for this lesson. By the end of the lesson, you should be able to understand the basic principles used to identify radial velocity signatures, relate the velocity display to the vertical wind profile, and apply velocity interpretation principles to the WSR-88D velocity products. 4 There are also three performance objectives with this lesson. The first objective is to be able to interpret Doppler velocity patterns under uniform, non-uniform, ambiguous, and meteorologically complex conditions. These are listed below. Move on when you are ready. 5 The second performance objective is the ability to construct vertical wind profiles for uniform and non-uniform horizontal wind conditions. And the final performance objective is to assess the meteorological conditions associated with the identified velocity patterns. 6 In this lesson, we will be discussing large scale velocity patterns. The second lesson will then focus on storm-scale velocity signatures. -
The Sunnyvale–Los A
NOVEMBER 2001 PICTURE OF THE MONTH 2805 PICTURE OF THE MONTH First WSR-88D Documentation of an Anticyclonic Supercell with Anticyclonic Tornadoes: The Sunnyvale±Los Altos, California, Tornadoes of 4 May 1998 JOHN P. M ONTEVERDI San Francisco State University, San Francisco, California WARREN BLIER National Weather Service Forecast Of®ce, Monterey, California GREG STUMPF National Severe Storms Laboratory, and Cooperative Institute for Mesoscale Meteorology Studies, University of Oklahoma, Norman, Oklahoma WILFRED PI National Weather Service Forecast Of®ce, Monterey, California KARL ANDERSON Second Nature, Sunnyvale, California 16 August 2000 and 12 June 2001 ABSTRACT On 4 May 1998, a pair of tornadoes occurred in the San Francisco Bay Area in the cities of Sunnyvale (F2 on the Fujita scale) and Los Altos (F1). The parent thunderstorm was anticyclonically rotating and produced tornadoes that were documented photographically to be anticyclonic as well, making for an extremely rare event. The tornadic thunderstorm was one of several ``pulse type'' thunderstorms that developed on out¯ow boundaries on the left ¯ank of an earlier-occurring thunderstorm east of San Jose. Satellite imagery showed that the tomadic storm moved northwestward along a sea-breeze boundary and ahead of the out¯ow boundary associated with the prior thun- derstorms. The shear environment into which the storm propagated was characterized by a straight hodograph with some cyclonic curvature, and by shear and buoyancy pro®les that were favorable for anticyclonically rotating updrafts. Mesoanticyclones were detected in the Monterey (KMUX) radar data in association with each tornado by the National Severe Storm Laboratory's (NSSL) new Mesocyclone Detection Algorithm (MDA) making this the only documented case of a tornadic mesoanticyclone in the United States that has been captured with WSR- 88D level-II data.