Application of wavelet and regression analysis in assessing temporal and geographic climate variability: Eastern Ontario, Canada as a case study

Regression and wavelet analysis have been employed to trace and quantify variation in temporal patterns (e.g., cycles and trends) between the instrument climate records of urban Ottawa and nearby rural areas in eastern Ontario. Possible links between observed climate change at these stations and possible natural and anthropogenic drivers were also investigated. Regression analysis indicates that the temperature in Ottawa increased, on average, at a rate of >0.01degreesC yr(-1) in comparison to adjacent rural areas over the last century. Wavelet analysis shows that this relative urban warming trend was primarily manifested in the form of multi-decadal and interseasonal cycles that are likely attributable to gradual increased winter heating in Ottawa (heat island effects) associated with population growth. We estimate that the 1degreesC increase in the Ottawa temperature is equivalent to an increase in population size of similar to400,000. In contrast, interannual variability correlates well between rural and urban areas with about the same temperature amplitudes.