| Popis: |
Spectral and wavelet analysis were used to identify trends and cycles in extreme temperature and precipitation events based on historical data (~100-150 years) from six climate stations within the “Maritime Region” of eastern North America. Many statistically significant climate cycles were identified using both spectral and Morlet wavelet analyses at each of these locations for both extreme high and low temperature and precipitation (rain, snow) data, with periodicities typically ranging from ~ 2–30 years. To assess potential drivers of these cyclical extreme weather events, the records of these events were compared, using cross wavelet analysis, to the climate indices of several teleconnections, including the 11-year Schwabe solar cycle, Atlantic Multidecadal Oscillation, North Atlantic Oscillation, Arctic Oscillation, El Niño Southern Oscillation and the Quasi–Biennial Oscillation. It was found that the 11-year solar cycle had the strongest influence over extreme temperature and precipitation in this region, whereas the remaining oscillations, with the exception the Quasi–Biennial Oscillation, exhibited complex interactions with one another, characterized a variety of both positive and negative modulating effects. The Quasi–Biennial Oscillation was found to drive high–frequency oscillations in extreme weather, particularly extreme precipitation. Overall, the findings of this study indicate that extreme weather events in this region have not substantially increased or decreased in number over time, but have been predominantly influenced by several cyclic climate phenomena. |
