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Chinook Vol. 9 No. 3

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Chinook Vol. 9 No. 3 .+ Learning Weather • • • A resource study kit suitable for students grade seven and up, prepared by the Atmospheric Environment Service of Environment Canada Includes new revised poster·size cloud chart Decouvrons la meteO ... Pochettes destinees aux eleves du secondaire et du collegial, preparees par Ie service de I'environnement atmos heri ue d'Environnement Canada Incluant un tableau revise descriptif des nuages Learning Weather Decouvrons la meteo A resource study kit, contains: Pochette documentaire comprenant: 1. Mapping Weather 1. Cartographie de la meteo A series of maps with exercises. Teaches how Serie de cartes accompagnees d'exercices. Oecrit weather moves. Includes climatic data for 50 Cana­ les fluctuations du temps et fournit des donnees dian locations. climatologiques pour 50 localites canadiennes. 2. Knowing Weather 2. Apprenons a connaitre la meteo Booklet discusses weather events, weather facts Brochure traitant d'evenements, de faits et de legen· and folklore, measurement of weather and several des meteorologiques. Techniques de I'observation et student projects to study weather. de la prevision de la met eo. Projets scolaires sur la 3. Knowing Clouds meteorologie. A cloud chart to help students identify various cloud 3. Apprenons a connaitre les nuages formations. Tableau descriptif des nuages aidant les elilves a identifier differentes formations. Cat. No. EN56·5311983·E Each kit $4.95 Cat. N° EN56·5311983F Chaque pochette: 4,95 $ Order kits from: Commandez les pochettes au : CANADIAN GOVERNMENT PUBLISHING CENTRE CENTRE D'EDITION DU GOUVERNEMENT DU OTTAWA, CANADA CANADA, K1A OS9 OTTAWA (CANADA) K1A OS9 Order Form (please print) Bon de commande Veuillez m'ex pedier _ _ exemplaire(s) de la pochette Please send me _ _ copy(ies) of Learning Weather at $4.95 "Decouvrons la meteo" it 4.95 $ la co pie. N° de cat. per copy. TOTAL $ . Cat. No .: EN56-53/1983E . EN56·53/1983F_ Name Nom School Adre sse Add ress City Ville Province Postal Code Province Code postal Ci·joint $ N° de compte o Account No. 0 Enclosed $ o B~i::ter Card 111111111111111 Expi ry Dat e Bank Date d'exp iration Signature Banque Signature Orders prepaid by peslar money order or cheque must be made to Ihe order of the Receiver General for Canada and addressed to Ihe Canadian Govern­ Les commandes sont payables a I'avance par cheque ou mandai rail a menl Publishing Centre, Ottawa (Canada) K lA 059. Also available through I'ordre du Receveur general du Canada et doivent eire adressees au Centre authorized bookstore agents or your local bookseller. Add 20% to prices for d'edition du gouvernemenl du Canada. Otlawa (Canada) K1A OS9 En vente books to be shipped outSide Canada Payable in Canadian funds aussi chez les agents libraires agrees ou chez volre libraire Telephone (819) 997-2560 Telex 053-4296 Egalement disponible en fram;ais: "Decouvrons la meteo" Also avaifable in English: "Learning Weather" N" de cat.: EN56-5311983F. Cat No EN56-531t983E. Canada The two articles by Barry Grace in this issue c;I,k«t/< Summer / Ete 1987 Vol. 9 No.3 - the Alberta chinook and the related phenomenon of soil erosion - are, in a sense, FROM THE EDITOR's DESK 51 a reminder that the name of our publication CHINOOKS 52 is connected with that infamous weather By Barry Grace phenomenon. In this issue we are revisiting the chinook and some of its important CHINOOK BIBLIOGRAPHY 55 impacts. Chinook's first issue in the fall of HOT AND COOL JULY BREEZES 61 1978 provided a satellite view of the cloud Weather Map Series, July 8 to 14, 1987 arch accompanying this warm, dry and gusty By Hans VanLeeuwen wind. ANSWERS TO ICEBERG QUESTIONS (Chinook Vol. 9 No.1) 61 Since the magazine has been in existence now for almost ten years, we felt it proper to WIND EROSION OF SOILS ON THE CANADIAN PRAIRIES 62 provide the readers with an up-to-date and By Barry Grace rather extensive bibliography of articles and CLIMATE QUIZ 64 books published on this most Canadian of weather phenomena. WINTER OF 1986-87 IN REVIEW 65 In this issue we also want to welcome to our By Amir Shabbar readership a large number of weather ob­ servers. Through the kind generosity of the EDITORIAL BOARD / CONSEIL DE REDACTION Atmospheric Environment Service, Chinook will be distributed to a select number of these Howard Freeland John W. Loder most valuable contributors to meteorology in Institute of Ocean Sciences Bedford Institute of Oceanography Canada. Sidney, British Columbia Dartmouth, Nova Scotia Weather observers playa vital role in piec­ Barry Grace John Maybank ing together the complex weather and climate Agriculture Canada Research Branch Saskatchewan Research Council picture. They lilre a group who go back in Lethbridge, Alberta Sa skatoon, Sas katchewan history more than two centuries - well before Yves Gratton Jerry Salloum Canada's Weather Service existed- and who Universite du Quebec a Rimouski Don Mills Collegiate can be found in many communities across Rimouski, Quebec City of North York, Ontario the length and breadth of Canada. Hans VanLeeuwen (Chairman) We welcome your comments and look Richard Leduc Ministere de l'environnement Atmospheric Environment Service forward to your contributions. We will en­ Quebec, Quebec Downsview, Ontario deavour to publish your observations in Chinook, particularly if they pertain to EDITOR Hans Vanleeuwen REDACTEUR TECHNICAL EDITOR Edward J Truhlar REDACTION TECHNIQUE peculiar, unusual orjust interesting weather BUSINESS MANAGER J Carr McLeod GESTIONNAIRE phenomena. Some of these are best described ARTWORK Bill Kiely and Joan Badger ILLUSTRATION TRANSLATION Joanne Gagnon Pacini TRADUCTION with pictures. We thus intend to start, with FOUNDER AND EDITOR 1978-1984 Michael J. Newark FONDATEUR EDITEUR 1978-1984 your cooperation, an Observer's Corner for ISSN 0705-4572 the purpose of sharing your observations and Published by: Publie par: insights with the meteorological and oceano­ Canadian Meleorological and Oceanographic SOCiety La Societe canadienne de meteorologie et d'oceanographie graphic communities in Canada. This desk has thus far not been flooded Prinled and produced in Canada and published quarterly by Edite et imprime au Canada Chinook est publie lous les with letters or contributions from our read­ Ihe Canadian Meteorological and Oceanographic Society. trois mois par la Societe canadienne de meleorologie ers. So we will assume either they are in the Suite 903. 151 Slater Sireet. Otlawa. Onl. K1P 5H3 Annual et d·oceanographie. Suite 903. 151. rue Slater. Ollawa subscription rates are $10.00 for CMOS members. $12.00 (Ontario) K1P 5H3. Les frais d'abonnement annuel sont de mail or you are still working on them. The for non-members and $15.00 for institutions. Contents copy- 10.00$ pour les membres de la SCMO. de 12.00$ pour bottom line is that we need to hear from you, rlg~t ~ the authors 1987 Copying done for other than les non -membres et de 15.00 $ pour les inslitutions Les personal or Internal rcference use without the expressed auteurs detiennent Ie droit exclusif d'exploiter leur oeuvre the good news, the bad news and your permission oJ the CMOS IS prOhibited. All correspondence litteraire (© 1987) Toute reproduction. sauf pour usage per- contributions. including requesls for special permiSSion or bulk orders sonnel au consultation interne, est interdite sans la permis- should be addressed to Chinook at the above address_ sion explicite de la SCMO. Toute correspondance doit ~Ire We also continue to need your assistance envoyae au Chinook a I'adresse ci-dessus. y compris les in spreading the word and in getting the Second Class Mail Registration No. 4508 demandes de permission speciale et les commandes en magazine into secondary schools, flying and Summer 1987 Dale of issue - Seplember 1987 gros. yacht clubs, radio and TV stations and all ~ourrier de deuxieme classe - enregistrement nO 4508 those groups who in one way or another have Eta 1987 Date de parulion - septembre 1987 an interest in weather and the oceans. Hans VanLeeuwen COVER COUVERTURE Striking views of the Chinook Arch near sun- Prises remarquables de l'arche du chinook, Contributions, enquiries, comments and sug­ set, with melting snow shown in the lower peu avant Ie coucher du solei!, ainsi qu'une gestions from readers are welcome. They right photograph. Courtesy: Evan Gushul, image de la fonte des neiges, en bas, a should be addressed to: retired photographer, Agriculture Research droite. Gracieusete de : Evan Gushul, photo- Editor, Chinook, Suite 903, 151 Slater Street, Station, Lethbridge, Alberta. graphe a la retraite, Station de recherches, Ottawa, Ont. K1 P 5H3. Agriculture Canada, Lethbridge, Alberta. 51 CHINOOKS by Barry Grace Chinook Arch at Lethbridge. Courtesy: Evan Gushul, retired Photographer, Agriculture Canada, Lethbridge. The climate of southern Alberta was 10 often referred to in historical records. Early explorers and traders in the late 1700s noted the warm west winds and 0 mild winter climate of the area, where the climate is dominated by chinook winds. Few regions in Canada are so -10 profoundly influenced by the direct and ~ indirect effects of a specific weather S phenomenon. ~ -20 Q) Chinook is the name applied to c. E Q) strong, warm, dry winds that sweep f- -30 Id j down the eastern slopes of the Rocky 800 E Mountains. Early North American leg­ o ends claim that the winds originated in -g ~ -40 the homeland of the Chinook Indians, 400 ~ who dwelt in the Columbia River area of Washington State. In other countries >. such as Austria, New Zealand and o~ 28 30 2 8 10 Japan, the winds that develop along the December 1984 January 1985 lee sides of mountain ranges are re­ ferred to as foehn winds. Figure 1 Daily maximum, minimum and Figure 2 Surface analysis, 0600 GMT, for Chinook winds in North America mean temperatures and daily total wind run January 2, 1985 indicating a high pressure influence the climate of Alberta, Sas­ for late December 1984 and early January over the Rocky Mountains and a low pres­ katchewan, Montana and North Dako­ 1985.
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