Abstract
In cold-regions climates, numerous environmental processes and socio-economic activities are significantly impacted by the timing of the seasonal advance and retreat of the 0 °C isotherm. This investigation examines 20th century trends and variability in spring and autumn 0 °C-isotherm dates over Canada. Results reveal considerable variability across the country. Significant trends toward earlier springs are observed over most of western Canada including a dramatic shift to earlier dates during the last 20–30 years. Central regions areassociated with smaller, generally insignificant earlier spring trends. Conversely, extreme eastern areas experience later springs. During autumn, isotherm dates show little change over the majority of the country. The observed spatial and temporal characteristics in the 0 °C-isotherm trends are reflected in past variations in several hydro-cryospheric variables over many regions of Canada including the timing of snowmelt and the dates of freshwater ice break-up. Investigation into the potential causes of observed variability in 0 °C-isotherm dates reveals that large-scale oscillations representing atmospheric/oceanic variations in the north Pacific and north Atlantic significantly relate to isotherm dates over western and eastern Canada, respectively, during both spring and autumn. Although significant, a relatively small amount of overall variance in isotherm dates is explained by the oscillations indicating the influence of other factors. Results from this study improve our knowledge of past trends and variability in 0°C-isotherm dates and resultant impacts on hydro-cryospheric processesover Canada. They also provide insight into potential future climatologic impacts given the possibility of climate change.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allen, W. T. R.: 1978, ‘Freeze-up, Break-up of Rivers and Lakes’, Plate 19 in Hydrological Atlas of Canada, Fisheries and Environment Canada.
Beltaos, S.: 2002, ‘Effects of Climate on Mid-winter Ice Jams’, Hydrol. Process. 16 (4), 789–804.
Bonsal, B. R., Prowse, T. D., and Lacroix, M. P.: 2001a, ‘Relationships between Spring 0°C IsothermDates and Hydrocryospheric Variables over Arctic Canada’, in International Symposium on Arc-ticFeedbacks to Global Change, October 25.27, 2001, Rovaniemi, Finland.
Bonsal, B. R., Shabbar, A., and Higuchi, K.: 2001b, ‘Impacts of Low Frequency Variability Modes on Canadian Winter Temperature’, Int. J. Clim. 21, 95–108.
Bonsal, B. R., Zhang, X., Vincent, L. A., and Hogg, W. D.: 2001c, ‘Characteristics of Daily and Extreme Temperatures over Canada’, J. Climate 14, 1959–1976.
Brimley, W. and Freeman, C.: 1997, ‘Trends in River Ice Cover in Atlantic Canada’, in Proceedings, 9th Workshop on River Ice, Fredericton, Canada, pp. 335–349.
Brown, R.: 2000, ‘Northern Hemisphere Snow Cover Variability and Change, 1915-97’, J. Climate 13, 2339–2355.
Burn, D. H.: 1994, ‘Hydrologic Effects of Climate Change in West-Central Canada’, J. Hydrol. 160, 53–70.
Cayan, D. R., Kammerdiener, S. A., Dettinger, M. D., Caprio, J. M., and Peterson, D. H.: 2001, ‘Changes in the Onset of Spring in theWestern United States’, Bull. Amer.Met. Soc. 82, 399–415.
Cunjak, R. A., Prowse, T. D., and Parrish, D. L.: 1998, ‘Atlantic Salmon in Winter; “The Season of Parr Discontent”’, Can. J. Fish. Aquat. Sci. 55(Suppl. 1), 161–180.
Gray, D.M. and Male, D. H. (eds.): 1981, Handbook of Snow, Pergamon Press, Willowdale, Canada, p. 776.
Groisman, P. Y., Karl, T. R., and Knight, R.W.: 1994a, ‘Observed Impact of Snow Cover on the Heat Balance and the Rise of Continental Spring Temperatures’ Science 263, 198–200.
Groisman, P. Y., Karl, T. R., Knight, R. W., and Stenchikov, G. L.: 1994b, ‘Changes in Snow Cover, Temperature, and Radiative Heat Balance over the Northern Hemisphere’, J. Climate 7, 1633–1656.
Hare, F. K. and Thomas M. K.: 1974, Climate Canada,Wiley Publishers of Canada Limited, Toronto, ON, p. 256.
Hoerling, M. P., Hurrell, J.W., and Xu, T.: 2001, ‘Tropical Origins for Recent North Atlantic Climate Change’, Science 292, 90–92.
Hurrell, J. W.: 1996, ‘Influence of Variations in Extratropical Wintertime Teleconnections on Northern Hemisphere Temperature’, Geophys. Res. Lett. 23, 665–668.
Hurrell, J. W. and van Loon, H.: 1997, ‘Decadal Variations in Climate Associated with the North Atlantic Oscillation’, Clim. Change 36, 301–326.
IPCC: 2001, in Houghton, J. T., Ding, Y., Griggs, D. J., Noguer, M., van der Linden, P. J., and Xiaosu, D. (eds.), IPCC Third Assessment Report: Climate Change 2001, Cambridge University Press, p. 944.
Jasek, M. J.: 1999, ‘1998 Break-up and Flood on the Yukon River at Dawson-Did El Niño and Climate Change Play a Role?’, in Shen, H. T. (ed.), Ice in Surface Waters, Balkema, Rotterdam, pp. 761–768.
Mantua, N. J., Hare, S. R., Zhang, Y., Wallace, J. M., and Francis, R. C.: 1997, ‘A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production’, Bull. Amer. Meteorol. Soc. 78, 1069–1079.
Marchand, P. J.: 1987, Life in the Cold, University Press of New England, Hanover, NH, U.S.A., p. 176.
Prowse, T. D. and Beltaos, S.: 2002, ‘Climatic Control of River-Ice Hydrology: A Review’, Hydrol. Process. 16, in press.
Rannie, W. F.: 1993, ‘Break-up and Freeze-up of the Red River at Winnipeg, Manitoba Canada in the 19th Century and Some Climatic Implications’, Clim. Change 5, 283–296.
Reycraft, J. and Skinner, W.: 1993, ‘Canadian Ice Conditions: An Indicator of Climate Variability’, Climatic Perspectives 15, 9–15.
Thompson, D. W. and Wallace, J. M.: 1998, ‘The Arctic Oscillation Signature in the Wintertime Geopotential Height and Temperature Fields’, Geophys. Res. Lett. 25, 1297–1300.
Thompson, D. W. and Wallace, J. M.: 2000, ‘Annular Modes in the Extratropical Circulation. Part I: Month to Month Variability’, J. Climate 13, 1000–1016.
Trenberth, K. E. and Hurrell, J. W.: 1994, ‘Decadal Atmosphere-Ocean Variations in the Pacific’, Clim. Dyn. 9, 303–319.
Vincent, L. A.: 1998, ‘A Technique for the Identification of Inhomogeneities in Canadian Temperature Series’, J. Climate 11, 1094–1104.
Vincent, L. A. and Gullett D. W.: 1999, ‘Creation of Historical and Homogeneous Temperature Datasets for Climate Change Analyses in Canada’, Int. J. Clim. 19, 1375–1388.
Vincent, L. A., Zhang, X., Bonsal, B. R., and Hogg, W. D.: 2002, ‘Homogenization of Daily Temperatures over Canada’, J. Climate 15, 1322–1334.
Wallace, J. M. and Gutzler, D. S.: 1981, ‘Teleconnections in the Geopotential Height Field during the Northern Hemisphere Winter’, Mon. Wea. Rev. 109, 784–812.
Zhang, X., Harvey, K. D., Hogg, W. D., and Yuzyk, T. R.: 2001, ‘Trends in Canadian Streamflow’, Water Resour. Res. 37, 987–998.
Zhang, X., Vincent, L. A., Hogg, W. D., and Niitsoo, A.: 2000, ‘Temperature and Precipitation Trends in Canada during the 20th Century’, Atmos. Ocean 38, 395–429.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bonsal, B.R., Prowse, T.D. Trends and Variability in Spring and Autumn 0 °C-Isotherm Dates over Canada. Climatic Change 57, 341–358 (2003). https://doi.org/10.1023/A:1022810531237
Issue Date:
DOI: https://doi.org/10.1023/A:1022810531237