An Improved Representation of Rimed Snow and Conversion to Graupel in a Multicomponent Bin Microphysics Scheme
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Severe Storms in the Midwest
Informational/Education Material 2006-06 Illinois State Water Survey SEVERE STORMS IN THE MIDWEST Stanley A. Changnon Kenneth E. Kunkel SEVERE STORMS IN THE MIDWEST By Stanley A. Changnon and Kenneth E. Kunkel Midwestern Regional Climate Center Illinois State Water Survey Champaign, IL Illinois State Water Survey Report I/EM 2006-06 i This report was printed on recycled and recyclable papers ii TABLE OF CONTENTS Abstract........................................................................................................................................... v Chapter 1. Introduction .................................................................................................................. 1 Chapter 2. Thunderstorms and Lightning ...................................................................................... 7 Introduction ........................................................................................................................ 7 Causes ................................................................................................................................. 8 Temporal and Spatial Distributions .................................................................................. 12 Impacts.............................................................................................................................. 13 Lightning........................................................................................................................... 14 References ....................................................................................................................... -
Quantification of Cloud Condensation Nuclei Effects on the Microphysical Structure of Continental Thunderstorms Using Polarimetr
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Dissertations & Theses in Earth and Atmospheric Earth and Atmospheric Sciences, Department of Sciences 11-2018 Quantification of Cloud Condensation Nuclei Effects on the Microphysical Structure of Continental Thunderstorms Using Polarimetric Radar Observations Kun-Yuan Lee University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/geoscidiss Part of the Atmospheric Sciences Commons, Meteorology Commons, and the Other Oceanography and Atmospheric Sciences and Meteorology Commons Lee, Kun-Yuan, "Quantification of Cloud Condensation Nuclei Effects on the Microphysical Structure of Continental Thunderstorms Using Polarimetric Radar Observations" (2018). Dissertations & Theses in Earth and Atmospheric Sciences. 113. https://digitalcommons.unl.edu/geoscidiss/113 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Dissertations & Theses in Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. i QUANTIFICATION OF CLOUD CONDENSATION NUCLEI EFFECTS ON THE MICROPHYSICAL STRUCTURE OF CONTINENTAL THUNDERSTORMS USING POLARIMETRIC RADAR OBSERVATIONS by Kun-Yuan Lee A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science Major: Earth and Atmospheric Sciences Under the Supervision of Professor Matthew S. Van Den Broeke Lincoln, Nebraska November, 2018 i QUANTIFICATION OF CLOUD CONDENSATION NUCLEI EFFECTS ON THE MICROPHYSICAL STRUCTURE OF CONTINENTAL THUNDERSTORMS USING POLARIMETRIC RADAR OBSERVATIONS Kun-Yuan Lee, M.S. University of Nebraska, 2019 Advisor: Matthew S. -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
A Comprehensive Observational Study of Graupel and Hail Terminal Velocity, Mass Flux, and Kinetic Energy
NOVEMBER 2018 H E Y M S F I E L D E T A L . 3861 A Comprehensive Observational Study of Graupel and Hail Terminal Velocity, Mass Flux, and Kinetic Energy ANDREW HEYMSFIELD National Center for Atmospheric Research, Boulder, Colorado MIKLÓS SZAKÁLL AND ALEXANDER JOST Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany IAN GIAMMANCO Insurance Institute for Business and Home Safety, Richburg, South Carolina ROBERT WRIGHT RLWA and Associates, Houston, Texas (Manuscript received 2 February 2018, in final form 24 August 2018) ABSTRACT This study uses novel approaches to estimate the fall characteristics of hail, covering a size range from about 0.5 to 7 cm, and the drag coefficients of lump and conical graupel. Three-dimensional (3D) volume scans of 60 hailstones of sizes from 2.5 to 6.7 cm were printed in three dimensions using acrylonitrile butadiene styrene (ABS) plastic, and their terminal velocities were measured in the Mainz, Germany, vertical wind tunnel. To simulate lump graupel, 40 of the hailstones were printed with maximum dimensions of about 0.2, 0.3, and 0.5 cm, and their terminal velocities were measured. Conical graupel, whose three dimensions (maximum dimension 0.1–1 cm) were estimated from an analytical representation and printed, and the terminal veloc- ities of seven groups of particles were measured in the tunnel. From these experiments, with printed particle 2 densities from 0.2 to 0.9 g cm 3, together with earlier observations, relationships between the drag coefficient and the Reynolds number and between the Reynolds number and the Best number were derived for a wide range of particle sizes and heights (pressures) in the atmosphere. -
Cloud Microphysics
Cloud microphysics Claudia Emde Meteorological Institute, LMU, Munich, Germany WS 2011/2012 Growth Precipitation Cloud modification Overview of cloud physics lecture Atmospheric thermodynamics gas laws, hydrostatic equation 1st law of thermodynamics moisture parameters adiabatic / pseudoadiabatic processes stability criteria / cloud formation Microphysics of warm clouds nucleation of water vapor by condensation growth of cloud droplets in warm clouds (condensation, fall speed of droplets, collection, coalescence) formation of rain, stochastical coalescence Microphysics of cold clouds homogeneous, heterogeneous, and contact nucleation concentration of ice particles in clouds crystal growth (from vapor phase, riming, aggregation) formation of precipitation, cloud modification Observation of cloud microphysical properties Parameterization of clouds in climate and NWP models Cloud microphysics December 15, 2011 2 / 30 Growth Precipitation Cloud modification Growth from the vapor phase in mixed-phase clouds mixed-phase cloud is dominated by super-cooled droplets air is close to saturated w.r.t. liquid water air is supersaturated w.r.t. ice Example ◦ T=-10 C, RHl ≈ 100%, RHi ≈ 110% ◦ T=-20 C, RHl ≈ 100%, RHi ≈ 121% )much greater supersaturations than in warm clouds In mixed-phase clouds, ice particles grow from vapor phase much more rapidly than droplets. Cloud microphysics December 15, 2011 3 / 30 Growth Precipitation Cloud modification Mass growth rate of an ice crystal diffusional growth of ice crystal similar to growth of droplet by condensation more complicated, mainly because ice crystals are not spherical )points of equal water vapor do not lie on a sphere centered on crystal dM = 4πCD (ρ (1) − ρ ) dt v vc Cloud microphysics December 15, 2011 4 / 30 P732951-Ch06.qxd 9/12/05 7:44 PM Page 240 240 Cloud Microphysics determined by the size and shape of the conductor. -
Graupel Or Hailstone), Some Negative Ions Transferred to the Colder Object What Causes the Charge Distribution? Part 2
ATM 10 Severe and Unusual Weather Prof. Richard Grotjahn L 15/16 http://canvas.ucdavis.edu/ Lecture topics: • Lightning – Formation of charge conditions – Demonstrations – Various types – Climatology – Damage – Safety do’s and don’ts – videos • Hail – Formation – Locations – Damage Short Video Segments • Lightning – Daytime lightning & sound (10 sec, .mov) – Night, slow crawlers (18 sec, mpg) – Night, city (10 sec, mpg) What is lightning? • A very large spark • Traveling through a poor conductor (air) What is thunder? • Lightning instantly heats air to ~30,000 C (~54,000 F)! • Heated air expands (ideal gas law) compressing adjacent air • Sound wave (thunder) is created Perceiving Thunder • Air attenuates (absorbs) sound, removing high frequencies sooner than low • You hear high pitch “Crack!” (from that part of lightning close to you) • followed by low rumbles for that part of lightning furthest away • Sound waves (like light) refract (bend) towards cooler air (recall mirages) • If you are too far away (~15km) you may not hear it, though you see a flash “heat lightning” • Sound travels • 1 km in 3 seconds • 1 mile in 5 seconds bolt traveling horizontally towards camera, then dipping to the ground Lightning Bolt = Giant Spark 1. Negative charge in cloud base attracts positive charge on ground (esp. high pts) 2. "Stepped leader" steps downward 50-100m at a time -- creates the jagged shape. Each step ~ 50/1,000,000 second 3. When step leader nears the ground, ground leaders may rise from taller objects 4. << BOOM!>> -- positive charge rushes up: this is much brighter RETURN STROKE. A short circuit. The stepped leader made the air conducting along that path and the return stroke follows that easier path. -
Storm Spotter's Checklist
ARE STRONG UPDRAFTS PRESENT? ARE YOU SEEING A “LOOK-ALIKE”? SUGGESTED REPORTING CRITERIA STORM SPOTTER’S CHECKLIST National Weather Service - Memphis, TN ⃞ Thick, sharp-edged anvil ⃞ Scud (not attached to cloud base, likely not URGENT (tornado, flash flood) ⃞ Large, persistent overshooting top rotating) • Tornado ⃞ Hard, cauliflower texture to updraft tower ⃞ Precipitation shaft (likely not rotating, often • Funnel cloud REPORTING TIPS... has a fuzzy or stringy appearance) • PERSISTENT rotating wall cloud ⃞ Moderate to strong inflow winds • Be clear when reporting location (are you ⃞ Smoke/Steam column (originates from a • PERSISTENT low-level rotation signatures giving your location or the event’s?) ⃞ Warm, moist air blowing into storm stationary point, likely not rotating) • Major flooding (roads closed, water rescues) • IMPACTS from heavy rainfall are more • Storm-related damage ⃞ Rain-free base ⃞ “Gustnado” (not associated with updraft, not important than instantaneous rates. ⃞ Inflow bands attached to cloud base) HIGH (non-tornadic supercell, flooding) • If you are unsure of what you’re seeing, make ⃞ Rising scud clouds (possibly) • Hail golf ball size or larger your report but express the uncertainty also. ⃞ Wall cloud WALL CLOUDS vs. SHELF CLOUDS... • Winds 65 mph or stronger • Reports of environmental conditions (outflow, • Persistent non-rotating wall cloud strong warm moist inflow, etc.) are important. • Flooding of uncommon areas WALL CLOUDS • Use teamwork: multiple distances and angles. ARE STRONG DOWNDRAFTS PRESENT? • suggest updraft MEDIUM (near or above severe tstm criteria) ⃞ Shelf cloud or roll cloud • • slope upward away from the precipitation Hail 3/4 inch to golf ball size SAFETY TIPS... ⃞ Rain foot or Dust foot • Winds 45 to 65 mph • Beware of flooding and lightning. -
Ociv-) 35 P Unclas
c F e F (NASA-CR-180170) A SlODY CE ~EVLBESTORfl ~a7-1~277 I ELEC'IRIClTY VIA S2ChM KNTEIiCEES 4 Eississippi Ociv-) 35 p CSCL 04B Unclas G3/47 43342 6 a e e a e A STUDY OF SEVERE STORM ELECTRICITY VIA STORM INTERCEPT e ROY T. ARNOLD and STEVEN D. HORSBURGH Department of Physics and Astronomy, University of i4ississippi University, MS 38677 e W. DAVID RUST and DON BURGESS National Severe Storms Laboratory Norman, OK 73069 December, 1985 e e a ABSTRACT a We have used storm electricity data, radar data, and visual observations both to present a case study for a supercell thunderstorm that occurred in the Texas ?an- handle on 19 June 1980 and to search for insight into how lightning to ground night be related to storm dynamics in the updraft/downdraft couplet in supercell storms. We observed that two-thirds of the lightning ground-strike points in the developing and maturing stages of a supercell thunderstorm occurred within the region surround- 0 ing the wall cloud (a cloud feature often characteristic of a supercell updraft) and on the southern flank of the precipitation. Electrical activity in the 19 June 1980 storm was what we consider to be typical for an isolated severe convective storm; the storm was atypical in that it was a right-mover. Lightning to ground reached a peak rate of 18/min and intracloud flashes were as frequent as 176/min in the final stage of the storm's life. 0 e 3 INTRODUCTION 6 Ground intercept of severe convective storms as a scientific project began in 1972 by the National Severe Storms Laboratory (NSSL) in collaboration with the University of Oklahoma (Golden and Morgan, 1972; Lee, 1981). -
2.3 Case Study Verification of Ruc/Maps Fog and Visibility Forecasts
Preprints, 9th Conf. on Aviation, Range, and Aerospace Meteorology, AMS, Orlando, FL, September 2000 2.3 CASE STUDY VERIFICATION OF RUC/MAPS FOG AND VISIBILITY FORECASTS Tatiana G. Smirnova* Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado/NOAA Forecast Systems Laboratory Boulder, Colorado Stanley G. Benjamin, John M. Brown NOAA Forecast Systems Laboratory Boulder, Colorado 1. INTRODUCTION predictions of surface conditions important for efficient operations in the vicinity of air terminals. Recently per- The Rapid Update Cycle (RUC) which runs operationally formed validations of MAPS/RUC hydrological cycle com- at the National Centers for Environmental Prediction ponents, such as precipitation, evapotranspiration and (NCEP) (Benjamin et al. 1999, 1998), and its experimen- soil moisture, as well as of skin temperature demonstrate tal version (Mesoscale Analysis and Prediction System - the model’s capability to represent surface processes MAPS) run at Forecast Systems Laboratory, were de- with a good degree of realism (Smirnova et al. 2000b). signed to provide frequently updated weather predictions Accurate prediction of aviation-impact variables for better guidance to aviation and other short-range fore- such as fog, surface visibility and cloud ceiling is impor- cast users. In January 2000, several additional aviation- tant for terminal operations. In this paper, a RUC visibility impact diagnostic variables became routinely available as algorithm (an extension to the Stoelinga-Warner (1999) part of the RUC output fields, including visibility, cloud algorithm) is presented and applied to native-grid RUC base (ceiling), stable cloud top, convective cloud top po- output to product diagnostic fields of surface visibility. tential, and surface wind gust potential. -
Rime and Graupel: Description and Characterization As Revealed by Low-Temperature Scanning Electron Microscopy
SCANNING VOL. 25, 121–131 (2003) Received: November 27, 2002 © FAMS, Inc. Accepted: February 20, 2003 Rime and Graupel: Description and Characterization as Revealed by Low-Temperature Scanning Electron Microscopy ALBERT RANGO,JAMES FOSTER,* EDWARD G. JOSBERGER,† ERIC F. ERBE,‡ CHRISTOPHER POOLEY,‡§ WILLIAM P. W ERGIN‡ Jornada Experimental Range, Agricultural Research Service (ARS), U. S. Department of Agriculture (USDA), New Mexico State University, Las Cruces, New Mexico; *Laboratory for Hydrological Sciences, NASA Goddard Space Flight Center, Green- belt, Maryland; †U. S. Geological Survey, Washington Water Science Center, Tacoma, Washington; ‡Soybean Genomics and Improvement Laboratory, ARS, USDA; §Hydrology and Remote Sensing Laboratory, ARS, USDA, Beltsville, Maryland, USA Summary: Snow crystals, which form by vapor deposition, ticle 1 to 3 mm across, composed of hundreds of frozen occasionally come in contact with supercooled cloud cloud droplets interspersed with considerable air spaces; the droplets during their formation and descent. When this oc- original snow crystal is no longer discernible. This study curs, the droplets adhere and freeze to the snow crystals in increases our knowledge about the process and character- a process known as accretion. During the early stages of istics of riming and suggests that the initial appearance of accretion, discrete snow crystals exhibiting frozen cloud the flattened hemispheres may result from impact of the droplets are referred to as rime. If this process continues, leading face of the snow crystal with cloud droplets. The the snow crystal may become completely engulfed in elongated and sinuous configurations of frozen cloud frozen cloud droplets. The resulting particle is known as droplets that are encountered on the more advanced stages graupel. -
Climate Change and Its Impacts in Japan, October 2009
Synthesis Report on Observations, Projections, and Impact Assessments of Climate Change Climate Change and Its Impacts in Japan October 2009 Ministry of Education, Culture, Sports, Science and Technology (MEXT) Japan Meteorological Agency (JMA) Ministry of the Environment (MOE) . Contents 1. Introduction ........................................................................................................................................1 2. Mechanisms of Climate Change and Contributions of Anthropogenic Factors — What are the Causes of Global Warming? ......................................................................................................2 2.1 Factors affecting climate change ...................................................................................................2 2.2 The main cause of global warming since the mid-20th century is anthropogenic forcing ...............3 2.3 Confidence in observation data and simulation results by models ................................................5 2.4 Changes on longer time scales and particularity of recent change................................................5 [Column 1] Definitions of Terms Related to Climate Change .....................................................8 [Column 2] Aerosols and Climate Change..................................................................................10 3. Past, Present, and Future of the Climate — What is the Current State and Future of Global Warming?.........................................................................................................................................11 -
A Comprehensive Observational Study of Graupel and Hail Terminal Velocity, Mass Flux, and Kinetic Energy
NOVEMBER 2018 H E Y M S F I E L D E T A L . 3861 A Comprehensive Observational Study of Graupel and Hail Terminal Velocity, Mass Flux, and Kinetic Energy ANDREW HEYMSFIELD National Center for Atmospheric Research, Boulder, Colorado MIKLÓS SZAKÁLL AND ALEXANDER JOST Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany IAN GIAMMANCO Insurance Institute for Business and Home Safety, Richburg, South Carolina ROBERT WRIGHT RLWA and Associates, Houston, Texas (Manuscript received 2 February 2018, in final form 24 August 2018) ABSTRACT This study uses novel approaches to estimate the fall characteristics of hail, covering a size range from about 0.5 to 7 cm, and the drag coefficients of lump and conical graupel. Three-dimensional (3D) volume scans of 60 hailstones of sizes from 2.5 to 6.7 cm were printed in three dimensions using acrylonitrile butadiene styrene (ABS) plastic, and their terminal velocities were measured in the Mainz, Germany, vertical wind tunnel. To simulate lump graupel, 40 of the hailstones were printed with maximum dimensions of about 0.2, 0.3, and 0.5 cm, and their terminal velocities were measured. Conical graupel, whose three dimensions (maximum dimension 0.1–1 cm) were estimated from an analytical representation and printed, and the terminal veloc- ities of seven groups of particles were measured in the tunnel. From these experiments, with printed particle 2 densities from 0.2 to 0.9 g cm 3, together with earlier observations, relationships between the drag coefficient and the Reynolds number and between the Reynolds number and the Best number were derived for a wide range of particle sizes and heights (pressures) in the atmosphere.