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Canso arine E v·ron e or s op Par 4 of 4 Pa s ys·ca Oceanog a y a d · 0 e a ~ffec s F: D. McCracken Editor Biological Station, St. Andrews, N. S., EOG 2XO January 1979 F·sheries & arine Serv·ce Tech ical Report o. 834 and Envi Nches et EnviilOM8f'lW1t CBnada 8eMce des et de Ia mer Fisheries and !VI'''''''n£> I.,:,:u".,.i,·o Technical KelPorts These reports contain scientific and technical information that represents an important contribution to existing knowledge but which for some reason may not be appropriate for primary scientific (i.e. Journal) Technical are directed primarily towards a world wide audience and have an international distribution. No restriction is placed on subject matter and the series reflects the broad interests and policies of the Fisheries and Marine Service, namely, fisheries management, technology and development, ocean and aquatic environ ments relevant to Canada. Technical Reports may be cited as full publications. The correct citation appears above the abstract of each report. Each will be abstracted in /H/UUlIC Sciences and Fisheries Abstracts and will be indexed annually in the Service's index to scientifie and technical publications. Numbers 1-456 in this series were issued as Technical Reports of the Fisheries Research Board of Canada. Numbers 457-714 were issued as Department of the Environment, Fisheries and Marine Service, Research and Director ate Technical Reports. The series name was changed with report number 715. Details on the availability of Technical Reports in hard copy may be obtained from the issuing establishment indicated on the front cover. Service des peches et de la mer Rapports techniques Ces rapports contiennent des renseignements scientifiques et techniques qui constituent une contribution importante aux connaissances actuelles mais qui, pour une raison ou pour une autre, ne semblent pas appropries pour la publication dans un journal scientifique. II n'y a aucune restriction quant au sujet, de fait, la serie reflete la vaste gamme des interets et des politiques du Service des peches et de la mer, notamment gestion des peches, techniques et developpement, sciences oceaniques et environnements aquatiques, au Canada. Les Rapports techniques peuvent etre consideres comme des publications completes. Le titre exact paraitra au haut du resume de chaque rapport, qui sera publie clans la revue Aquatic Sciences and Fisheries Abstracts et qui figurera dans l'index annuel des publications scientifiques et techniques du Service. numeros 1-456 de cette serie ont ete publies atitre de Rapports techniques de I'Office des recherches sur les pecheries du Canada. Les numeros 457-700, atitre de techniques de la Direction de la recherche et du de'veloplpernent, Service des peches et de la mer, de I'Environnement. Le nom de la serie a ete a du numero 701. La page couverture porte Ie nom de I'etablissement auteur ou I'on peut se procurer les sous couverture cartonnee. design by Christine Rusk Fisheries and Marine Service Technical I<epor'\: H34 January 1979 CANSO MARINE ENVIRONMENT WORKSHOP PART 4 OF 4 PARTS Physical and Geological Oceanography F. D. McCracken Editor St.' Andrews Biological Station Resource I3ranch Fisheries and Oceans Canada St. Andrews, New Brunswick EOG 2XO This is the one hundred and fifteenth Technical Report from the Biological Station, St. Andrews, N.B. ii @ Mi ni ster of Supply and Servi ces Canada 1979 Cat. No. rs 97-6/834 rSSN 0701-7620 iii TABLE OF CONTENTS Cl imate and ice in the Strait of Canso, A. D. J. O'Neill Discussion •••• 10 Flow in the Strait of Canso and St. Georges Bay, Nova Scotia, K. F. Drinkwater 11 Discussion ••• 17 Flow patterns in Chedabucto Bay, Nova Scotia, D. J. Lawrence 19 Discussion. 30 Observations on particle distribution in the Strait of Canso and vicinity, Kate Kranck and R. W. Sheldon. 31 Suspended and sedimented particulate matter in St. Georges Bay, B. T. Hargrave 37 Discussion ••••• 40 COflillents on residual current patterns in the inshore area south of Cape Breton Island, R. W. Trites • ••••..••• • .• 41 Nutrient entrainment in Chedabucto Bay and its possible effects on production, K. F. Drinkwater 51 Discussion 54 Influence of pollution in the Canso area, a summary, R. C. H. Wilson 55 Discussion. 59 A summary of industries located in communities bordering the Strait of Canso, Joan K. Day •••••.•••.••..• 61 Changes in the water quality of the Northumberland Strait, N.B., J. S. S. Lakshmi narayana and H. Bourque ••• 67 Discussion of other papers presented which have been published elsewhere 81 -1- CLIMATE AND ICE IN THE STRAIT OF CANSO REGION by A. D. J. O'Neill Atmospheric Environment Service Bedford, Nova Scotia -2 ABSTRACT O'Neill, A. D. J. 1979. Cl imate and ice in the Strait of Canso region. Fish. Mar. Servo Tech. Rep. 834. From examination of cl imatological records for the Strait of Canso region, it is cone 1uded that Causeway construction did not result in any significant change in cl imate there. The limited data available, however, indicate that substantial changes in sea-ice regime occurred along Nova Scoti a's At 1ant ic coast subsequent to Ca useway construction. It is suggested that breachi ng of the Causeway would have marginal effects on the cl irnate in the region but might result in more severe sea-ice conditions along the east coast of Nova Scotia should the breach permit passage of significant quantities of ice through the Strait to the Atlantic. Key words: Climate, weather conditions, sea ice, Canso Strait, causeway, precipitation, air temperature -3- INTRODUCTI ON list of reference material concerning the climate of the Strait of Canso region. This paper summarizes the cl imatology of ICE DATA the Strait of Canso Region of Nova Scotia, including a brief review of sea-ice conditions. The Atmospheric Environment Service Ice In particular, an attempt is made to examine the Branch is ble for reconnaissance and cl imate of the area both prior to and subsequent forecasti ice conditions in Canadian marine to construction of the Canso Causeway. areas and di information on ice climatol AES Branch was established in 1957, to construction of the Canso EXISTING DATABASE Causeway. infonllation on ice conditions or to construction is available from a number of mi 1aneous sources. For thi s CLIMATIC DATA Dn2sE~ntation I have ut il i zed data from the Ice as of the • 1946) Lists of climatological stations in the emented by additional "Ion from an vicinity of Canso Strait, detail of the c1 by Forviard (1954). observing programs at these stations and their periods of operation are presented in Table 1. Fortuitously, observations of precipitation and CLIMATE OF THE Sl~AIT OF CANSO REGION temperature are available from Port Hastings, on the shores of the Strait, for a fairly extended period prior to construction of the Causeway. Canso Strait is eet to both continental Subsequent to Causeway construction in the and maritime climatic uences due to its mid-1950's, climatic data are available from a location on the eastern side of a cant nental number of stations in the area. land mass in middle latitudes. For the same reason, it is di affected the In addition to the si ific passage of m"ld"-lat"! frontal ions and observations noted above, ized, duri summer occasionally l"ies close to the broader-scale information on various of t of ca 1 storms. These factors, regional cl imate is available in the ional combined more local influences such as the Climatic Atlas (Anon. 1970a) and in a number of seasonal freez! of the Gul f of SL Lawrence, other publ ications available from the produce a mid-l itude climate best Atmospheric Environment Service. Among the characterized by its variabil ity. latter, particular reference will be made to "Recent Cl imatic Fluctuations in Canada" (rhOlililS At Port IldstinlJs on the sharps of the 1975), which contains an ana"lysis of trends in Strait, llIean deli IIlaJ<1l1lum Lures Y'dllge regional cl imate in the Maritime I)rovinces and frolJl -L8°C in to 22. in Jlugust with is highly relevant to this paper. An Appendix correspondi IIJean minima ranging from to the present paper presents a fairly complete -9.9°Cln 9°C in The Table 1. Climatological stations in the Canso Strait Station name Period of operation Observation program -----~--,~- Canso Dec. 1963-Dec. 1971 Hourly observations p"lus rainfall rate I:ddy Point Dec. 1<)11- Hourly obs0rval:ions plus relinfall relL0 Point Tupper r~,lrch 19!(J- Prpc !pi ta!.ioll dlld LemperdLur'I' Port Hawkesbury Feb. 195C)-[Jec. 1CJb 1 vJind velocity Port Hastings Jan. l874-June 1913 Precipitation and temperature (incomplete) ,June 1959- Precipitation and temperature Port Hastings Canal July 1974- \~ind velocity Port Hood July 1950-Nov. 1952 Precipitation and temperature Feb. 1961-Nov. 1971 Precipitation and temperature rort Hood Island July 1972-July 1975 Precipitation, temperature, wind velocity ---, continental influence is reflected in the .56 extreme temperatures on record which are 37.2°C ;;> extreme maximum) and -26. JOC minimum). ng season at Port Hastings ( ned as the number of days with mean dai temperature above 5.6°C) averages 191 days e freezing temperatures occur on an average of 158 days, j I ! ! ! I I I! J-.J III ! ! ! I !~-L.LJ Precipitation falls on an average of 129 1945 1950 1955 1960 1965 1970 year of which 22 days between October are, normally, days with measurable Fig. 1. Decadal moving mean temperatures in annua 1 on at Port Atlantic region 1940-75 (mean credited to mm whi 165 mm water mid-year of each 10-yr period) buted by snow.