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Long-lead forecasting of precipitation and wheat yields in Saskatchewan using teleconnection indices

Teleconnections among the central, east equatorial Pacific, the Pacific/North American (PNA) pattern, and Southern Oscillation (SO) and monthly precipitation, monthly temperature, and spring wheat yields in Saskatchewan are examined. When sea surface temperatures in the central equatorial Pacific are warmer than the air temperatures (strong El Niño) there is an upward flux of water vapour into the atmosphere, convection, heat released by condensation, a strengthening of the westerlies and a vitalization of the Hadley circulation. When sea surface temperatures are colder than the air temperatures (strong La Niña) in the central equatorial Pacific it produces the opposite influence on atmospheric processes. Composite analysis reveals that El Niño and La Niña are the primary modulators of the Pacific/North American pattern and movement of surface cyclones across the western continent. Correlation and composite analyses indicate that between 1950 and 1998 warmer than normal sea surface temperatures in the central and east equatorial Pacific during the winter and early spring (El Niño) are associated with cooler and wetter conditions during the May through July period in Saskatchewan and higher wheat yields. Conversely cooler than normal sea surface temperatures in the central and east equatorial Pacific during the winter and early spring (La Niña) are associated with hotter and drier conditions during the May through July period in Saskatchewan and lower wheat yields. The relationship appears to be strongest for the Brown soil zone and weakest for the Black soil zone in Saskatchewan.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-11142008-134119
Date14 November 2008
CreatorsGarnett, Edmund Ray
ContributorsRipley, Earle, Paul, Alex, Maule, Charles P., Archibold, O. W. (Bill), Wheaton, Elaine E.
PublisherUniversity of Saskatchewan
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://library.usask.ca/theses/available/etd-11142008-134119/
Rightsunrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.

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