Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-23T09:39:52.080Z Has data issue: false hasContentIssue false
  • English
  • Français

Urban-induced Increase in Length of the Freeze-free Season and Its Environmental Implications

Published online by Cambridge University Press:  24 August 2009

Lawrence C. Nkemdirim  and
D. Venkatesan
Lawrence C. Nkemdirim
Affiliation:
Department of Geography, University of Calgary, Calgary, Alberta T2N 1N4, Canada
D. Venkatesan
Affiliation:
Department of Physics, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
Get access Rights & Permissions [Opens in a new window]

Extract

There has been a systematic increase in the length of the freeze-free season in several Canadian cities since 1940. This increase is believed to be due mainly to urbanization. Although the rate of urbanization during the period 1940–70 was not significantly higher than the rates in the preceding decades, urban growth during those thirty years was accompanied by higher levels of fossil-fuel conversion, which produced higher temperatures in towns and cities than in surrounding rural areas, and a generally reinforced ‘greenhouse effect’. The higher temperatures in turn combined with other urban factors to enhance the length of the freeze-free season.

In a northern climate where the growing-season is already precariously short, a longer freeze-free season should have beneficial effects on agriculture and affect other aspects of the environment. There is general agreement among research workers that the energetics of solar variability are too small to affect tropospheric or stratospheric processes directly to any significant degree. This study reinforces belief in the importance of local factors; such influences tend to override any subtle connection between solar variability and the weather.

Type
Main Papers
Information
Environmental Conservation , Volume 13 , Issue 4 , Winter 1986 , pp. 347 - 350
Copyright
Copyright © Foundation for Environmental Conservation 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baier, W. (1977). Crop-weather models and their use in yield assessment. WMO Technical Note 151, World Meteorological Organization, Geneva, Switzerland: pp. 75–106.Google Scholar
Energy, Mines and Resources [cited as EMR] (1982). Current Energy Statistics. Canada Department of Energy, Mines and Resources, Ottawa, Canada: viii + 73 pp.Google Scholar
Fowler, J.M. (1972). Energy and the environment. The Science Teacher, 39, pp. 10–2.Google Scholar
Hubbert, M.K. (1973). Survey of world energy resources. The Canadian Mining and Metallurgical Bulletin, 66, pp. 37–54.Google Scholar
Huff, F.A. (1975). Urban effects on the distribution of convective rainfall. Wat. Resour. Res., 11, pp. 889–96.CrossRefGoogle Scholar
Huff, F.A. & Changnon, S.A. Jr (1973). Precipitation modification by major urban areas. Bull. Amer. Meteor. Soc., 54, pp. 1220–34.2.0.CO;2>CrossRefGoogle Scholar
Langbein, W.B. (1949). Annual Runoff in the United States. USGS Circ. 5, Department of the Interior, Washington, DC, USA: 80 pp.Google Scholar
Longley, R.W. (1972). The Climate of the Prairie Provinces, Climatological Studies No 13, Atmospheric Environment Service, Environment Canada, Toronto, Ontario, Canada: vii + 79 pp.Google Scholar
Machta, L. & Carpenter, T. (1971). Trends in high cloudiness at Denver and Salt Lake City. Pp. 410–5 in Man's Impact on the Climate (Eds Matthews, W.H., Kellogg, W.W. & Robinson, G.B.). M.I.T. Press, Cambridge, Massachusetts, USA: [not available for checking].Google Scholar
Mckay, G.A., Maybank, J., Mooney, O.R. & Pelton, W.L. (1967). The Agricultural Climate of Saskatchewan. Climatological Studies No 10, Department of Transport, Meteorological Branch, Toronto, Ontario, Canada: vii + 62 pp.Google Scholar
Nkemdirim, L.C. (1981 a). Cloudiness and wind speed as factors on a climatic anomaly. Tellus, 33, pp. 12–8.Google Scholar
Nkemdirim, L.C. (1981 b). Extra-urban and intra-urban rainfall enhancement by a medium-sized city. Water Res. Bull., 17, pp. 116–24.Google Scholar
Nkemdirim, L.C. (1985). On the Correlation between Urban and Landuse and Soil Temperatures. Paper presented at the International Symposium on Concepts and Techniques of Applied Climatology, Waltair, India, 03 1985: 12 pp., illustr. (typescr.).Google Scholar
Nkemdirim, L.C. & Venkatesan, D. (1985 a). The nature of the distribution in space and time of the length of the annual frost-free season in Canada, east of the Rockies. Geog. Annaler, 61A, pp. 1–12.Google Scholar
Nkemdirim, L.C. & Venkatesan, D. (1985 b). An Urban impact model for changes in the length of the frost-free season at selected Canadian stations. Climatic Change, 7, pp. 343–62.CrossRefGoogle Scholar
Robertson, G. W. (Ed.) (1983). Guidelines on Crop Weather Models. World Climate Applications Programme Task Force on Crop-Weather Models, WCP-50, WMO, Geneva, Switzerland: [not available for checking].Google Scholar
Waggoner, P.E. (1983). Agriculture and climate change by more carbon dioxide. Pp. 383–418 in Changing Climate: Report of the Carbon Dioxide Assessment Committee. National Academy Press, Washington, D.C., USA: [not available for checking].Google Scholar
Weller, G., Baker, D.J. Jr, Gates, W.L., MacCracken, M.C., Manabe, S. & Harr, J.H. Vonder (1983). Detection and monitoring of CO-induced climate changes. Pp. 292–382 in Changing Climate: Report of the Carbon Dioxide Assessment Committee. National Academy Press, Washington, D.C., USA: [not available for checking].Google Scholar