Manual on the Observation of Clouds and Other Meteors
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
3 Atmospheric Motion
Final PDF to printer CHAPTER 3 Atmospheric Motion MOTION OF THE EARTH’S ATMOSPHERE has a great influence on human lives by controlling climate, rainfall, weather patterns, and long-range transportation. It is driven largely by differences in insolation, with influences from other factors, including topography, land-sea interfaces, and especially rotation of the planet. These factors control motion at local scales, like between a mountain and valley, at larger scales encompassing major storm systems, and at global scales, determining the prevailing wind directions for the broader planet. All of these circulations are governed by similar physical principles, which explain wind, weather patterns, and climate. Broad-scale patterns of atmospheric circulation are shown here for the Northern Hemisphere. Examine all the components on this figure and think about what you know about each. Do you recognize some of the features and names? Two features on this figure are identified with the term “jet stream.” You may have heard this term watching the nightly weather report or from a captain on a cross-country airline flight. What is a jet stream and what effect does it have on weather and flying? Prominent labels of H and L represent areas with relatively higher and lower air pressure, respectively. What is air pressure and why do some areas have higher or lower pressure than other areas? Distinctive wind patterns, shown by white arrows, are associated with the areas of high and low pressure. The winds are flowing outward and in a clockwise direction from the high, but inward and in a counterclockwise direction from the low. -
Climate and Atmospheric Circulation of Mars
Climate and QuickTime™ and a YUV420 codec decompressor are needed to see this picture. Atmospheric Circulation of Mars: Introduction and Context Peter L Read Atmospheric, Oceanic & Planetary Physics, University of Oxford Motivating questions • Overview and phenomenology – Planetary parameters and ‘geography’ of Mars – Zonal mean circulations as a function of season – CO2 condensation cycle • Form and style of Martian atmospheric circulation? • Key processes affecting Martian climate? • The Martian climate and circulation in context…..comparative planetary circulation regimes? Books? • D. G. Andrews - Intro….. • J. T. Houghton - The Physics of Atmospheres (CUP) ALSO • I. N. James - Introduction to Circulating Atmospheres (CUP) • P. L. Read & S. R. Lewis - The Martian Climate Revisited (Springer-Praxis) Ground-based observations Percival Lowell Lowell Observatory (Arizona) [Image source: Wikimedia Commons] Mars from Hubble Space Telescope Mars Pathfinder (1997) Mars Exploration Rovers (2004) Orbiting spacecraft: Mars Reconnaissance Orbiter (NASA) Image credits: NASA/JPL/Caltech Mars Express orbiter (ESA) • Stereo imaging • Infrared sounding/mapping • UV/visible/radio occultation • Subsurface radar • Magnetic field and particle environment MGS/TES Atmospheric mapping From: Smith et al. (2000) J. Geophys. Res., 106, 23929 DATA ASSIMILATION Spacecraft Retrieved atmospheric parameters ( p,T,dust...) - incomplete coverage - noisy data..... Assimilation algorithm Global 3D analysis - sequential estimation - global coverage - 4Dvar .....? - continuous in time - all variables...... General Circulation Model - continuous 3D simulation - complete self-consistent Physics - all variables........ - time-dependent circulation LMD-Oxford/OU-IAA European Mars Climate model • Global numerical model of Martian atmospheric circulation (cf Met Office, NCEP, ECMWF…) • High resolution dynamics – Typically T31 (3.75o x 3.75o) – Most recently up to T170 (512 x 256) – 32 vertical levels stretched to ~120 km alt. -
Soaring Weather
Chapter 16 SOARING WEATHER While horse racing may be the "Sport of Kings," of the craft depends on the weather and the skill soaring may be considered the "King of Sports." of the pilot. Forward thrust comes from gliding Soaring bears the relationship to flying that sailing downward relative to the air the same as thrust bears to power boating. Soaring has made notable is developed in a power-off glide by a conven contributions to meteorology. For example, soar tional aircraft. Therefore, to gain or maintain ing pilots have probed thunderstorms and moun altitude, the soaring pilot must rely on upward tain waves with findings that have made flying motion of the air. safer for all pilots. However, soaring is primarily To a sailplane pilot, "lift" means the rate of recreational. climb he can achieve in an up-current, while "sink" A sailplane must have auxiliary power to be denotes his rate of descent in a downdraft or in come airborne such as a winch, a ground tow, or neutral air. "Zero sink" means that upward cur a tow by a powered aircraft. Once the sailcraft is rents are just strong enough to enable him to hold airborne and the tow cable released, performance altitude but not to climb. Sailplanes are highly 171 r efficient machines; a sink rate of a mere 2 feet per second. There is no point in trying to soar until second provides an airspeed of about 40 knots, and weather conditions favor vertical speeds greater a sink rate of 6 feet per second gives an airspeed than the minimum sink rate of the aircraft. -
River Ice Management in North America
RIVER ICE MANAGEMENT IN NORTH AMERICA REPORT 2015:202 HYDRO POWER River ice management in North America MARCEL PAUL RAYMOND ENERGIE SYLVAIN ROBERT ISBN 978-91-7673-202-1 | © 2015 ENERGIFORSK Energiforsk AB | Phone: 08-677 25 30 | E-mail: [email protected] | www.energiforsk.se RIVER ICE MANAGEMENT IN NORTH AMERICA Foreword This report describes the most used ice control practices applied to hydroelectric generation in North America, with a special emphasis on practical considerations. The subjects covered include the control of ice cover formation and decay, ice jamming, frazil ice at the water intakes, and their impact on the optimization of power generation and on the riparians. This report was prepared by Marcel Paul Raymond Energie for the benefit of HUVA - Energiforsk’s working group for hydrological development. HUVA incorporates R&D- projects, surveys, education, seminars and standardization. The following are delegates in the HUVA-group: Peter Calla, Vattenregleringsföretagen (ordf.) Björn Norell, Vattenregleringsföretagen Stefan Busse, E.ON Vattenkraft Johan E. Andersson, Fortum Emma Wikner, Statkraft Knut Sand, Statkraft Susanne Nyström, Vattenfall Mikael Sundby, Vattenfall Lars Pettersson, Skellefteälvens vattenregleringsföretag Cristian Andersson, Energiforsk E.ON Vattenkraft Sverige AB, Fortum Generation AB, Holmen Energi AB, Jämtkraft AB, Karlstads Energi AB, Skellefteå Kraft AB, Sollefteåforsens AB, Statkraft Sverige AB, Umeå Energi AB and Vattenfall Vattenkraft AB partivipates in HUVA. Stockholm, November 2015 Cristian -
Contrail-Cirrus and Their Potential for Regional Climate Change
Contrail-Cirrus and Their Potential for Regional Climate Change Kenneth Sassen Department of Meteorology, University of Utah, Salt Lake City, Utah ABSTRACT After reviewing the indirect evidence for the regional climatic impact of contrail-generated cirrus clouds (contrail- cirrus), the author presents a variety of new measurements indicating the nature and scope of the problem. The assess- ment concentrates on polarization lidar and radiometric observations of persisting contrails from Salt Lake City, Utah, where an extended Project First ISCCP (International Satellite Cloud Climatology Program) Regional Experiment (FIRE) cirrus cloud dataset from the Facility for Atmospheric Remote Sensing has captured new information in a geographical area previously identified as being affected by relatively heavy air traffic. The following contrail properties are consid- ered: hourly and monthly frequency of occurrence; height, temperature, and relative humidity statistics; visible and in- frared radiative impacts; and microphysical content evaluated from in situ data and contrail optical phenomenon such as halos and coronas. Also presented are high-resolution lidar images of contrails from the recent SUCCESS experiment, and the results of an initial attempt to numerically simulate the radiative effects of an observed contrail. The evidence indicates that the direct radiative effects of contrails display the potential for regional climate change at many midlati- tude locations, even though the sign of the climatic impact may be uncertain. However, new information suggests that the unusually small particles typical of many persisting contrails may favor the albedo cooling over the greenhouse warming effect, depending on such factors as the geographic distribution and patterns in day versus night aircraft usage. -
Touching the Clouds Activity Guide
Touching the Clouds Activity Guide Purpose Provide a mental representation of each cloud type Create a tactile cloud identification chart Overview Individuals will construct and touch a tactile model of common types of clouds to learn how to describe the clouds based on their shape and texture. They will compare their descriptions with the standard classifications using the cloud types identified in the GLOBE Clouds Protocol. Time: 45 minutes to 1 ½ hours, depending on individual’s age Level: All Materials (per person) One large sheet of cardstock (18” x 12”) Tape One set of Braille labels for each cloud type and/or markers One small feather A layered piece of blanket or soft fabric (eight 1’ X 1” pieces) Cotton balls of varied sizes One tissue Organza or a similar material, cut into pieces, one layered 1” x 1” piece Pillow stuffing, one 1” x 1” piece A tsp of sand Three paper clips Liquid glue Scissors Baby Wipes Preparation Use tape to divide the large cardstock sheet in four sections: one for the cloud title at the top and three for the altitudes: using a portrait layout, place three pieces of tape horizontally, from side to side of the sheet. 1. 1” off the upper edge of the sheet 2. 8” off the upper edge of the sheet 1 Steps What to do and how to do it: Making A Tactile Cloud Identification Chart 1. Discuss that clouds come in three basic shapes: cirrus, stratus and cumulus. a. Feel of the 4” feather and describe it; discuss that these wispy clouds are high in the sky and are named cirrus. -
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE FORECASTING CALIFORNIA THUNDERSTORMS a Thesis Submitted in Partial Fulfillment of the Re
CALIFORNIA STATE UNIVERSITY, NORTHRIDGE FORECASTING CALIFORNIA THUNDERSTORMS A thesis submitted in partial fulfillment of the requirements For the degree of Master of Arts in Geography By Ilya Neyman May 2013 The thesis of Ilya Neyman is approved: _______________________ _________________ Dr. Steve LaDochy Date _______________________ _________________ Dr. Ron Davidson Date _______________________ _________________ Dr. James Hayes, Chair Date California State University, Northridge ii TABLE OF CONTENTS SIGNATURE PAGE ii ABSTRACT iv INTRODUCTION 1 THESIS STATEMENT 12 IMPORTANT TERMS AND DEFINITIONS 13 LITERATURE REVIEW 17 APPROACH AND METHODOLOGY 24 TRADITIONALLY RECOGNIZED TORNADIC PARAMETERS 28 CASE STUDY 1: SEPTEMBER 10, 2011 33 CASE STUDY 2: JULY 29, 2003 48 CASE STUDY 3: JANUARY 19, 2010 62 CASE STUDY 4: MAY 22, 2008 91 CONCLUSIONS 111 REFERENCES 116 iii ABSTRACT FORECASTING CALIFORNIA THUNDERSTORMS By Ilya Neyman Master of Arts in Geography Thunderstorms are a significant forecasting concern for southern California. Even though convection across this region is less frequent than in many other parts of the country significant thunderstorm events and occasional severe weather does occur. It has been found that a further challenge in convective forecasting across southern California is due to the variety of sub-regions that exist including coastal plains, inland valleys, mountains and deserts, each of which is associated with different weather conditions and sometimes drastically different convective parameters. In this paper four recent thunderstorm case studies were conducted, with each one representative of a different category of seasonal and synoptic patterns that are known to affect southern California. In addition to supporting points made in prior literature there were numerous new and unique findings that were discovered during the scope of this research and these are discussed as they are investigated in their respective case study as applicable. -
History of Frontal Concepts Tn Meteorology
HISTORY OF FRONTAL CONCEPTS TN METEOROLOGY: THE ACCEPTANCE OF THE NORWEGIAN THEORY by Gardner Perry III Submitted in Partial Fulfillment of the Requirements for the Degree of Bachelor of Science at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June, 1961 Signature of'Author . ~ . ........ Department of Humangties, May 17, 1959 Certified by . v/ .-- '-- -T * ~ . ..... Thesis Supervisor Accepted by Chairman0 0 e 0 o mmite0 0 Chairman, Departmental Committee on Theses II ACKNOWLEDGMENTS The research for and the development of this thesis could not have been nearly as complete as it is without the assistance of innumerable persons; to any that I may have momentarily forgotten, my sincerest apologies. Conversations with Professors Giorgio de Santilw lana and Huston Smith provided many helpful and stimulat- ing thoughts. Professor Frederick Sanders injected thought pro- voking and clarifying comments at precisely the correct moments. This contribution has proven invaluable. The personnel of the following libraries were most cooperative with my many requests for assistance: Human- ities Library (M.I.T.), Science Library (M.I.T.), Engineer- ing Library (M.I.T.), Gordon MacKay Library (Harvard), and the Weather Bureau Library (Suitland, Md.). Also, the American Meteorological Society and Mr. David Ludlum were helpful in suggesting sources of material. In getting through the myriad of minor technical details Professor Roy Lamson and Mrs. Blender were indis-. pensable. And finally, whatever typing that I could not find time to do my wife, Mary, has willingly done. ABSTRACT The frontal concept, as developed by the Norwegian Meteorologists, is the foundation of modern synoptic mete- orology. The Norwegian theory, when presented, was rapidly accepted by the world's meteorologists, even though its several precursors had been rejected or Ignored. -
Graphical Area Forecast User Guide a Guide for the Transition from Arfors to GAF
Graphical Area Forecast User Guide A guide for the transition from ARFORs to GAF October 2017 | Version 1.2 Graphical Area Forecast User Guide Document Control Revision history VERSION DATE DESCRIPTION AUTHOR 1 15 September 2017 Final version Elizabeth Heba Update to provide clarification on AIRMETs 1.1 13 October 2017 Elizabeth Heba and SIGMETs Update to GAF samples and worked example 1.2 20 October 2017 Additional text in Area Briefing (NAIPS) Ashwin Naidu Section Update to abbreviation examples Approval for release DATE NAME Position Signature National Manager Aviation 20 October 2017 Gordon Jackson Meteorological Services Version number Date of issue th Version 1.2 20 October 2017 © Commonwealth of Australia 2017 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced without prior written permission from the Bureau of Meteorology. Requests and inquiries concerning reproduction and rights should be addressed to the Production Manager, Communication Section, Bureau of Meteorology, GPO Box 1289, Melbourne 3001. Information regarding requests for reproduction of material from the Bureau website can be found at www.bom.gov.au/other/copyright.shtml ii Graphical Area Forecast User Guide Table of Contents 1 Purpose .......................................................................................................................................... 1 2 Introduction ................................................................................................................................... -
Persistent Contrails and Contrail Cirrus. Part I: Large-Eddy Simulations from Inception to Demise
DECEMBER 2014 L E W E L L E N E T A L . 4399 Persistent Contrails and Contrail Cirrus. Part I: Large-Eddy Simulations from Inception to Demise D. C. LEWELLEN,O.MEZA,* AND W. W. HUEBSCH West Virginia University, Morgantown, West Virginia (Manuscript received 2 October 2013, in final form 10 March 2014) ABSTRACT Large-eddy simulations with size-resolved microphysics are used to model persistent aircraft contrails and contrail-induced cirrus from a few wing spans behind the aircraft until their demise after many hours. Schemes for dynamic local ice binning and updating coupled radiation dynamically as needed in individual columns were developed for numerical efficiency, along with a scheme for maintaining realistic ambient turbulence over long times. These capabilities are used to study some of the critical dynamics involved in contrail evo- lution and to explore the simulation features required for adequate treatment of different components. A ‘‘quasi 3D’’ approach is identified as a useful approximation of the full dynamics, reducing the computation to allow a larger parameter space to be studied. Ice crystal number loss involving competition between different crystal sizes is found to be significant for both young contrails and aging contrail cirrus. As a consequence, the sensitivity to the initial number of ice crystals in the contrail above a threshold is found to decrease signifi- cantly over time, and uncertainties in the ice deposition coefficient and Kelvin effect for ice crystals assume an increased importance. Atmospheric turbulence is found to strongly influence contrail properties and lifetime in some regimes. Water from fuel consumption is found to significantly reduce aircraft-wake-induced ice crystal loss in colder contrails. -
MSE3 Ch14 Thunderstorms
Chapter 14 Copyright © 2011, 2015 by Roland Stull. Meteorology for Scientists and Engineers, 3rd Ed. thunderstorms Contents Thunderstorms are among the most violent and difficult-to-predict weath- Thunderstorm Characteristics 481 er elements. Yet, thunderstorms can be Appearance 482 14 studied. They can be probed with radar and air- Clouds Associated with Thunderstorms 482 craft, and simulated in a laboratory or by computer. Cells & Evolution 484 They form in the air, and must obey the laws of fluid Thunderstorm Types & Organization 486 mechanics and thermodynamics. Basic Storms 486 Thunderstorms are also beautiful and majestic. Mesoscale Convective Systems 488 Supercell Thunderstorms 492 In thunderstorms, aesthetics and science merge, making them fascinating to study and chase. Thunderstorm Formation 496 Convective Conditions 496 Thunderstorm characteristics, formation, and Key Altitudes 496 forecasting are covered in this chapter. The next chapter covers thunderstorm hazards including High Humidity in the ABL 499 hail, gust fronts, lightning, and tornadoes. Instability, CAPE & Updrafts 503 CAPE 503 Updraft Velocity 508 Wind Shear in the Environment 509 Hodograph Basics 510 thunderstorm CharaCteristiCs Using Hodographs 514 Shear Across a Single Layer 514 Thunderstorms are convective clouds Mean Wind Shear Vector 514 with large vertical extent, often with tops near the Total Shear Magnitude 515 tropopause and bases near the top of the boundary Mean Environmental Wind (Normal Storm Mo- layer. Their official name is cumulonimbus (see tion) 516 the Clouds Chapter), for which the abbreviation is Supercell Storm Motion 518 Bulk Richardson Number 521 Cb. On weather maps the symbol represents thunderstorms, with a dot •, asterisk , or triangle Triggering vs. Convective Inhibition 522 * ∆ drawn just above the top of the symbol to indicate Convective Inhibition (CIN) 523 Trigger Mechanisms 525 rain, snow, or hail, respectively. -
Airplane Icing
Federal Aviation Administration Airplane Icing Accidents That Shaped Our Safety Regulations Presented to: AE598 UW Aerospace Engineering Colloquium By: Don Stimson, Federal Aviation Administration Topics Icing Basics Certification Requirements Ice Protection Systems Some Icing Generalizations Notable Accidents/Resulting Safety Actions Readings – For More Information AE598 UW Aerospace Engineering Colloquium Federal Aviation 2 March 10, 2014 Administration Icing Basics How does icing occur? Cold object (airplane surface) Supercooled water drops Water drops in a liquid state below the freezing point Most often in stratiform and cumuliform clouds The airplane surface provides a place for the supercooled water drops to crystalize and form ice AE598 UW Aerospace Engineering Colloquium Federal Aviation 3 March 10, 2014 Administration Icing Basics Important Parameters Atmosphere Liquid Water Content and Size of Cloud Drop Size and Distribution Temperature Airplane Collection Efficiency Speed/Configuration/Temperature AE598 UW Aerospace Engineering Colloquium Federal Aviation 4 March 10, 2014 Administration Icing Basics Cloud Characteristics Liquid water content is generally a function of temperature and drop size The colder the cloud, the more ice crystals predominate rather than supercooled water Highest water content near 0º C; below -40º C there is negligible water content Larger drops tend to precipitate out, so liquid water content tends to be greater at smaller drop sizes The average liquid water content decreases with horizontal