DOCSLIB.ORG

Read Book Snowflakes Pdf Free Download

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Read Book Snowflakes Pdf Free Download SNOWFLAKES PDF, EPUB, EBOOK Laura Ellen Anderson,Cerrie Burnell | 32 pages | 05 Sep 2013 | Scholastic | 9781407135038 | English | London, United Kingdom Snowflakes PDF Book USA Today. Chronicle of Higher Education. Libbrecht is a professor of physics at the California Institute of Technology Caltech. A basic capped column is shaped like two wheels on an axle, or an empty spool. Check out our "Identical-Twin" snowflakes! The term referred to the color of snow, referring to valuing white people over black people. Story of Snow. Some on the left have worked to embrace snowflake. Free trial Try Snowflake free for 30 days and experience the cloud data platform that helps eliminate the complexity, cost, and constraints inherent with other solutions. Namespaces Article Talk. The earliest recorded musings on these delicate shapes date to B. This process is known as the Wegener— Bergeron—Findeisen process. Top definition. How are snow crystals made, and why do they have the shapes they do? Click on the link to see the book on Amazon, including a look inside. American Association for the Advancement of Science. You run into similar difficulties when you try to make definitive lists of all sorts of things—types of breads, cookies, or pastries; articles of clothing; breeds of dog; types of hobbies; musical instruments; etc. Fernlike Stellar Dendrites These crystals are like Stellar Dendrites above , but larger and leafier, with many sidebranches that resemble the branches of a fern. The terms "generation snowflake" and "snowflake generation" are frequently used in reference to use of trigger warnings and safe spaces , or to describe young adults as anti- free speech , specifically in reference to a practice referred to as deplatforming. In the s, "snowflake" was used by abolitionists in Missouri to refer to those who opposed the abolition of slavery. This has nothing to do with politics. Over 26 million visitors so far! An overly sensitive person that doesn't take criticism well. At that stage, the snowflake has the shape of a minute hexagon. Snow crystals come in two main types. National Geographic. They form when the atmosphere is cold enough to prevent them from fusing or melting and becoming sleet or rain. No two alike? Weekly Demo Join us for a live Snowflake demo Learn how to easily and securely store, integrate, and analyze data with near-infinite scalability, enabled automatically or on the fly. Wikimedia Commons has media related to Snowflakes. Related words cuck , beta , safe space , soyboy , triggered , SJW , millennials. Data Lake. Prove it! Regardless of whether their opinions are objectionable or abhorrent, Fox insists we must hear views that do not agree with our own in order to learn how to tackle them. That would require Putin having access to the sophisticated technology used by Stuttering John! Gimme a break! Malkin argues the provision has "cultural consequences" in that it "reduces the incentives for somethings to grow up and seek independent lives and livelihoods". Not all snowflakes look like six pointed stars. In her syndicated column, Michelle Malkin criticized the provision of the Affordable Care Act which requires employer- based health coverage to extend to an employee's adult offspring up to 26 years of age, describing it as the "slacker mandate" and calling these young adults "precious snowflakes". Over a century later in the s, black people who were seen as acting too white were mocked as snowflakes. This is not meant to be a formal definition of snowflake like most terms we define on Dictionary. Snow is a cluster of ice crystals that form in the atmosphere and retain their shape as they collectively fall upon Earth. See also: Snow science. Ice and water are all around us, and they are fascinating to learn about. Snowflakes Writer Data Warehouse. This article is about a slang term for a personality trait. Register Now. Retrieved 4 April Toward a Grand Unified Theory of Snowflakes. American Meteorological Society. You run into similar difficulties when you try to make definitive lists of all sorts of things—types of breads, cookies, or pastries; articles of clothing; breeds of dog; types of hobbies; musical instruments; etc. Libbrecht Regardless of whether their opinions are objectionable or abhorrent, Fox insists we must hear views that do not agree with our own in order to learn how to tackle them. No question is off limits! Categories : s slang Alt-right American political neologisms Internet memes introduced in Pejorative terms for people Political terminology Linguistic controversies Political culture Words coined in the s. Since the micro-environment and its changes are very nearly identical around the snowflake, each arm tends to grow in nearly the same way. Try Snowflake free for 30 days and experience the cloud data platform that helps eliminate the complexity, cost, and constraints inherent with other solutions. Snowflakes: a chapter from the book of nature. Top definition. You will also see that these crystals are not perfectly symmetrical. International Olympic Committee. There is no exact number; it depends on how many types you care to define. Cengage Learning. Retrieved 14 June The six "arms" of the snowflake, or dendrites, then grow independently from each of the corners of the hexagon, while either side of each arm grows independently. Help Learn to edit Community portal Recent changes Upload file. By Any Other Name. Archived from the original PDF on This has nothing to do with politics. When you go outside to look at the falling snow, magnifier in hand, you can use this chart to guide your search for exotic snowflakes. As Nakaya discovered, shape is also a function of whether the prevalent moisture is above or below saturation. Trump is such a snowflake and cannot focus on his job because he is frustrated by the media diminishing his achievements. Snowflakes are also often used as symbols representing winter or cold conditions. Since there can be no such thing as a final, definitive catalog, we pared the number down to one we consider convenient for snowflake watching. Just how many different types of snowflakes are there? Snowflakes Reviews Join the Data Cloud. Archived from the original PDF on The shape of the snowflake is determined broadly by the temperature and humidity at which it is formed. You run into similar difficulties when you try to make definitive lists of all sorts of things—types of breads, cookies, or pastries; articles of clothing; breeds of dog; types of hobbies; musical instruments; etc. Make sense? Rimed Snowflakes and Graupel Snow crystals grow inside clouds made of water droplets. Kepler and his contemporaries could not have known how much this matters. The International Classification for Seasonal Snow on the Ground describes snow crystal classification, once it is deposited on the ground, that include grain shape and grain size. Identical Twin Snowflakes? Virtually Unlimited Performance and Scale. Join us for a live Snowflake demo Learn how to easily and securely store, integrate, and analyze data with near-infinite scalability, enabled automatically or on the fly. As Nakaya discovered, shape is also a function of whether the prevalent moisture is above or below saturation. You care? If you look carefully, you will see that the sidebranches mostly run parallel to their neighboring branches. Freeze Joke. First a column forms around -6 C, or 21 F , and then plates grow on the ends of the columns around C, or 5 F. Prove it! BigAlDell June 29, Some on the left have worked to embrace snowflake. Story of Snow. Why are they all so different, and how come the six branches grow so similarly? He says he can see why it was chosen. John Doe saw that I agreed with Jane Doe on an issue, and he blocked me; I never knew he was so petty snowflake. Categories : Precipitation Snow. Whichever way the wind blows, they will just be taken with it. Wikimedia Commons. Categories : s slang Alt-right American political neologisms Internet memes introduced in Pejorative terms for people Political terminology Linguistic controversies Political culture Words coined in the s. At that stage, the snowflake has the shape of a minute hexagon. These crystals grow by incorporating water molecules from the surrounding air into their pattern. The shape of a snowflake is determined primarily by the temperature and humidity at which it is formed. In heraldry, the snowflake is a stylized charge , often used to represent winter or winter sports. Not all snowflakes look like six pointed stars. The chart on the right lists 35 snowflake types, which covers most of what you will find under your magnifier. Retrieved 25 December Start for Free. Could Be". In the s, "snowflake" was used by abolitionists in Missouri to refer to those who opposed the abolition of slavery. A lot of snowflakes together can make for a blizzard, or they can make for a very big dump of snow. Managing Data, Not Infrastructure Instantly and near-infinitely scale dedicated computing resources for every user and workload with a near-zero management platform. Snowflakes Read Online But first, have a look at some examples Stellar dendrites are also quite large and common, so they are readily spotted on your sleeve, especially if you are wearing a dark fabric. London: Biteback Publishing. Top definition. The idea, here, is whiteness—like snow. They are most often seen in bitter cold weather. Surry Hills. Oct 3 Word of the Day. The Day. It's the stuff of self-help books and inspirational posters and elementary school assurances. Watch Now. A snowflake just landed on your nose. Categories : s slang Alt-right American political neologisms Internet memes introduced in Pejorative terms for people Political terminology Linguistic controversies Political culture Words coined in the s.
Load more

Recommended publications
  • Snowflake Shapes Activity
    Primary Sources in the Classroom Smithsonian Institution Archives Wilson A. “Snowflake” Bentley Institutional History Division Snowflake Shape Activity siarchives.si.edu WILSON A. BENTLEY: SNOWFLAKE SHAPE ACTIVITY Objectives: Students will learn about how snowflakes form and the types of shapes that snowflakes are composed of. They will practice observational and comparison skills. They will identify snowflake types based on their shape. Time: 45 – 65 minutes (Adjust Time As Needed) ‐ introduction, (suggested: 15­ 20 minutes) ‐ study snowflake shapes outside, (suggested: 20 minutes) – if snow is falling ‐ study snowflake shapes inside, (suggested: 10 minutes) ‐ examine snowflakes and classify them by their shapes, (suggested: 10­15 minutes) Skills: Observation, Knowledge of basic shapes, Compare and contrast Content Area: Science, Art Materials: To study real snowflakes out of doors: ‐ cardboard, 8 x 10, one for every four students ‐ sheet of black felt or velvet, 8 x 10, one for every four students ‐glue ‐ magnifying glasses Classroom project: (contained below) ‐ snowflake type chart ‐ unidentified snowflake images answer sheet (2 sheets) Grade Level: Grades 3‐6 Historical Overview: For over forty years, Wilson “Snowflake” Bentley (1865‐ 1931) photographed thousands of individual snowflakes and perfected the innovative photomicrographic technique. His photographs and publications provide valuable scientific records of snow crystals and their many types. Five hundred of his snowflake photos now reside in the Smithsonian Institution Archives, donated by Bentley in 1903 to protect against “all possibility of loss and destruction, through fire or accident.” © Jericho Historical Society 1 Primary Sources in the Classroom Smithsonian Institution Archives Wilson A. “Snowflake” Bentley Institutional History Division Snowflake Shape Activity siarchives.si.edu Wilson A.
    [Show full text]
  • Click Here to View a Sample Chapter of the Pandemic Population
    2020 by Tim Elmore All rights reserved. You have beeN graNted the NoN-exclusive, NoN-traNsferable right to access aNd read the text of this e-book oN screeN. No parts of this book may be reproduced, traNsmitted, decompiled, reverse eNgiNeered, or stored iN or iNtroduced iNto aNy iNformatioN storage or retrieval system iN aNy form by aNy meaNs, whether electroNic or mechaNical, Now kNowN or hereiNafter iNveNted, without express writteN permissioN from the publisher. Published by AmazoN iN associatioN with GrowiNg Leaders, INc. PandemicPopulation.com Pandemics, Protests, and Panic Attacks: A History Defined by Tragedy There is an age-old story that illustrates the state of millions of American teens today. It’s the tale of a man who sat in a local diner waiting for his lunch. His countenance was down, he was feeling discouraged, and his tone was melancholy. When his waitress saw he was feeling low, she immediately suggested he go see Grimaldi. The circus was in town, and Grimaldi was a clown who made everyone laugh. The waitress was certain Grimaldi could cheer up her sad customer. Little did she know with whom she was speaking. The man looked up at her and replied, “But, ma’am. I am Grimaldi.” In many ways, this is a picture of the Pandemic Population. On the outside, they’re clowning around on Snapchat and TikTok, laughing at memes and making others laugh at filtered photos on social media. Inside, however, their mental health has gone south. It appears their life is a comedy, but in reality, it feels like a tragedy.
    [Show full text]
  • Alone Together: Exploring Community on an Incel Forum
    Alone Together: Exploring Community on an Incel Forum by Vanja Zdjelar B.A. (Hons., Criminology), Simon Fraser University, 2016 B.A. (Political Science and Communication), Simon Fraser University, 2016 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Arts in the School of Criminology Faculty of Arts and Social Sciences © Vanja Zdjelar 2020 SIMON FRASER UNIVERSITY FALL 2020 Copyright in this work rests with the author. Please ensure that any reproduction or re-use is done in accordance with the relevant national copyright legislation. Declaration of Committee Name: Vanja Zdjelar Degree: Master of Arts Thesis title: Alone Together: Exploring Community on an Incel Forum Committee: Chair: Bryan Kinney Associate Professor, Criminology Garth Davies Supervisor Associate Professor, Criminology Sheri Fabian Committee Member University Lecturer, Criminology David Hofmann Examiner Associate Professor, Sociology University of New Brunswick ii Abstract Incels, or involuntary celibates, are men who are angry and frustrated at their inability to find sexual or intimate partners. This anger has repeatedly resulted in violence against women. Because incels are a relatively new phenomenon, there are many gaps in our knowledge, including how, and to what extent, incel forums function as online communities. The current study begins to fill this lacuna by qualitatively analyzing the incels.co forum to understand how community is created through online discourse. Both inductive and deductive thematic analyses were conducted on 17 threads (3400 posts). The results confirm that the incels.co forum functions as a community. Four themes in relation to community were found: The incel brotherhood; We can disagree, but you’re wrong; We are all coping here; and Will the real incel come forward.
    [Show full text]
  • Version 2, 08/09/2017 20:48:33
    A Psychological Profile of the Alt-Right 1 A Psychological Profile of the Alt-Right Patrick S. Forscher1 and Nour S. Kteily2 1Department of Psychological Science, University of Arkansas, 2Department of Management and Organizations, Kellogg School of Management, Northwestern University. Author notes Data and materials for this project can be found at https://osf.io/xge8q/ Conceived research: Forscher & Kteily; Designed research: Forscher & Kteily; Collected data: Forscher & Kteily; Analyzed data: Forscher & Kteily; Wrote paper: Forscher & Kteily; Revised paper: Forscher & Kteily. Address correspondence to Patrick S. Forscher, Department of Psychological Science, University of Arkansas, 216 Memorial Hall, Fayetteville, AR, 72701 (Email: [email protected]). A Psychological Profile of the Alt-Right 2 Abstract The 2016 U.S. presidential election coincided with the rise the “alternative right” or “alt- right”. Although alt-right associates wield considerable influence on the current administration, the movement’s loose organizational structure has led to disparate portrayals of its members’ psychology, compounded by a lack of empirical investigation. We surveyed 447 alt-right adherents on a battery of psychological measures, comparing their responses to those of 382 non- adherents. Alt-right adherents were much more distrustful of the mainstream media and government; expressed higher Dark Triad traits, social dominance orientation, and authoritarianism; reported high levels of aggression; and exhibited extreme levels of overt intergroup bias, including blatant dehumanization of racial minorities. Cluster analyses suggest that alt-right supporters may separate into two subgroups: one more populist and anti- establishmentarian and the other more supremacist and motivated by maintaining social hierarchy. We argue for the need to give overt bias greater empirical and theoretical consideration in contemporary intergroup research.
    [Show full text]
  • A Field Guide to Falling Snow
    Basic Snowflake Forms (from SnowCrystals.com) Although no two snowflakes are exactly alike, snow crystal forms usually fall into several broad categories. You can find a more descriptive guide in the book – The Snowflake: Winter’s Secret Beauty. Stellar Dendrites Dendrite means "tree-like", which describes the multi-branched appearance of these snow crystals. Stellar dendrites have six symmetrical main branches and a large number of randomly placed sidebranches. They can also be large, perhaps 5mm in diameter. Although they have complex shapes, each stellar dendrite is a single crystal of ice. The molecular ordering of the water molecules is the same from one side of the crystal to the other. Sectored Plates What identifies these crystals are the numerous ice ridges that seem to divide the plate-like arms into sectors -- hence the name. Like the stellar dendrites, sectored plates are flat, thin slivers of ice that grow into in a stunning diversity of complex shapes. Hollow Columns Plate-like snow crystals get the most attention, but columnar crystals are the main constituents of many snowfalls. The columns are hexagonal, like a wooden pencil, and they often form with conical hollow features in their ends. Needles Columnar crystals can grow so long and thin that they look like ice needles. Sometimes the needles contain thin hollow regions, and sometimes the ends split into additional needle branches. Spatial Dendrites Not all snowflakes form as thin flat plates or slender columns. Spatial dendrites are made from many individual ice crystals jumbled together. Each branch is like one arm of a stellar crystal, but the different branches are oriented randomly.
    [Show full text]
  • 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.
    [Show full text]
  • International Olympic Committee, Lausanne, Switzerland
    A PROJECT OF THE INTERNATIONAL OLYMPIC COMMITTEE, LAUSANNE, SWITZERLAND. WWW.OLYMPIC.ORG TEACHING VALUESVALUES AN OLYYMPICMPIC EDUCATIONEDUCATION TOOLKITTOOLKIT WWW.OLYMPIC.ORG D R O W E R O F D N A S T N E T N O C TEACHING VALUES AN OLYMPIC EDUCATION TOOLKIT A PROJECT OF THE INTERNATIONAL OLYMPIC COMMITTEE, LAUSANNE, SWITZERLAND ACKNOWLEDGEMENTS The International Olympic Committee wishes to thank the following individuals for their contributions to the preparation of this toolkit: Author/Editor: Deanna L. BINDER (PhD), University of Alberta, Canada Helen BROWNLEE, IOC Commission for Culture & Olympic Education, Australia Anne CHEVALLEY, International Olympic Committee, Switzerland Charmaine CROOKS, Olympian, Canada Clement O. FASAN, University of Lagos, Nigeria Yangsheng GUO (PhD), Nagoya University of Commerce and Business, Japan Sheila HALL, Emily Carr Institute of Art, Design & Media, Canada Edward KENSINGTON, International Olympic Committee, Switzerland Ioanna MASTORA, Foundation of Olympic and Sport Education, Greece Miquel de MORAGAS, Centre d’Estudis Olympics (CEO) Universitat Autònoma de Barcelona (UAB), Spain Roland NAUL, Willibald Gebhardt Institute & University of Duisburg-Essen, Germany Khanh NGUYEN, IOC Photo Archives, Switzerland Jan PATERSON, British Olympic Foundation, United Kingdom Tommy SITHOLE, International Olympic Committee, Switzerland Margaret TALBOT, United Kingdom Association of Physical Education, United Kingdom IOC Commission for Culture & Olympic Education For Permission to use previously published or copyrighted
    [Show full text]
  • Reverse-Engineering Twitter's Content Removal
    “We Believe in Free Expression...” Reverse-Engineering Twitter’s Content Removal Policies for the Alt-Right The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:38811534 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Contents The Problem & The Motivation .............................................................................. 4 Free Speech: Before and After the Internet ......................................................... 5 Speech on Twitter .............................................................................................. 11 Defining the Alt-Right ....................................................................................... 13 The Alt-Right on Social Media ......................................................................... 14 Social Media Reaction to Charlottesville .......................................................... 17 Twitter’s Policies for the Alt-Right ................................................................... 19 Previous Work ................................................................................................... 21 Structure of this Thesis .....................................................................................
    [Show full text]
  • Great Meme War:” the Alt-Right and Its Multifarious Enemies
    Angles New Perspectives on the Anglophone World 10 | 2020 Creating the Enemy The “Great Meme War:” the Alt-Right and its Multifarious Enemies Maxime Dafaure Electronic version URL: http://journals.openedition.org/angles/369 ISSN: 2274-2042 Publisher Société des Anglicistes de l'Enseignement Supérieur Electronic reference Maxime Dafaure, « The “Great Meme War:” the Alt-Right and its Multifarious Enemies », Angles [Online], 10 | 2020, Online since 01 April 2020, connection on 28 July 2020. URL : http:// journals.openedition.org/angles/369 This text was automatically generated on 28 July 2020. Angles. New Perspectives on the Anglophone World is licensed under a Creative Commons Attribution- NonCommercial-ShareAlike 4.0 International License. The “Great Meme War:” the Alt-Right and its Multifarious Enemies 1 The “Great Meme War:” the Alt- Right and its Multifarious Enemies Maxime Dafaure Memes and the metapolitics of the alt-right 1 The alt-right has been a major actor of the online culture wars of the past few years. Since it came to prominence during the 2014 Gamergate controversy,1 this loosely- defined, puzzling movement has achieved mainstream recognition and has been the subject of discussion by journalists and scholars alike. Although the movement is notoriously difficult to define, a few overarching themes can be delineated: unequivocal rejections of immigration and multiculturalism among most, if not all, alt- right subgroups; an intense criticism of feminism, in particular within the manosphere community, which itself is divided into several clans with different goals and subcultures (men’s rights activists, Men Going Their Own Way, pick-up artists, incels).2 Demographically speaking, an overwhelming majority of alt-righters are white heterosexual males, one of the major social categories who feel dispossessed and resentful, as pointed out as early as in the mid-20th century by Daniel Bell, and more recently by Michael Kimmel (Angry White Men 2013) and Dick Howard (Les Ombres de l’Amérique 2017).
    [Show full text]
  • Qanon and Facebook
    The Boom Before the Ban: QAnon and Facebook Ciaran O’Connor, Cooper Gatewood, Kendrick McDonald and Sarah Brandt 2 ‘THE GREAT REPLACEMENT’: THE VIOLENT CONSEQUENCES OF MAINSTREAMED EXTREMISM / Document title: About this report About NewsGuard This report is a collaboration between the Institute Launched in March 2018 by media entrepreneur and for Strategic Dialogue (ISD) and the nonpartisan award-winning journalist Steven Brill and former Wall news-rating organisation NewsGuard. It analyses Street Journal publisher Gordon Crovitz, NewsGuard QAnon-related contents on Facebook during a provides credibility ratings and detailed “Nutrition period of increased activity, just before the platform Labels” for thousands of news and information websites. implemented moderation of public contents spreading NewsGuard rates all the news and information websites the conspiracy theory. Combining quantitative and that account for 95% of online engagement across the qualitative analysis, this report looks at key trends in US, UK, Germany, France, and Italy. NewsGuard products discussions around QAnon, prominent accounts in that include NewsGuard, HealthGuard, and BrandGuard, discussion, and domains – particularly news websites which helps marketers concerned about their brand – that were frequently shared alongside QAnon safety, and the Misinformation Fingerprints catalogue of contents on Facebook. This report also recommends top hoaxes. some steps to be taken by technology companies, governments and the media when seeking to counter NewsGuard rates each site based on nine apolitical the spread of problematic conspiracy theories like criteria of journalistic practice, including whether a QAnon on social media. site repeatedly publishes false content, whether it regularly corrects or clarifies errors, and whether it avoids deceptive headlines.
    [Show full text]
  • 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.
    [Show full text]
  • Cold Season Cloud Seeding
    Weather Modification UNDERSTANDING Cloud seeding—a form of weather modification— ALBERTA CANADA COLD SEASON is a safe, scientific, time-tested, and proven set of Cloud Seeding technologies used to enhance rain and snow, re- ND duce hail damage, and alleviate fog. The benefits ID of cloud seeding can be measured in additional WY water for cities and agriculture, as well as the re- NV UT duction of damage from severe weather. CA CO KS TX Target area—Cold-season cloud-seeding Target area—Warm-season cloud-seeding A ground-based generator is used to burn a silver iodide solution to release microscopic silver-iodide particles which can create additional ice crystals, then snow, in winter clouds. Research has shown that placing equipment at high elevations increases cloud seeding effectiveness. NAWMC Members Cold Season Seeding California Department of Water Resources When moist air flows over the mountains, water vapor Colorado Water Conservation Board condenses and forms clouds composed of water droplets. These droplets become “super cooled” and have the unique Desert Research Institute quality to remain liquid even at temperatures below freez- North Dakota Atmospheric Resource Board ing. Given enough time and mixing with surrounding air, many of the droplets will evaporate, but under the correct Texas Department of Licensing and Regulation conditions some will eventually become ice crystals, grow Utah Division of Water Resources into snowflakes and precipitate to the ground. Cloud seed- Wyoming Water Development Office ing provides an opportunity to increase the number of ice crystals that can become snowflakes. NAWMC Associate Members Who Conducts Cloud Seeding? Central Arizona Water Conservation District In North America, cloud-seeding programs are conducted in Metropolitan Water District of Southern California California, Colorado, Idaho, Nevada, Utah, Wyoming, Kansas, Santa Barbara County Water Agency North Dakota, and Texas, as well as Alberta, Canada.
    [Show full text]