Hydroclimatic Scenarios Using Dendroclimatic, Historical and GCM-Based Records Over the Northwestern Great Plains

• Main Author: Lapp, Suzan Laurie
• Other Authors: Sauchyn, David, Leavitt, Peter, Piwowar, Joseph, Barrow, Elaine, Bonsal, Barrie, Fleming, Sean
• Format: Thesis
• Language: English
• Published: Faculty of Graduate Studies and Research, University of Regina 2012
• Subjects: Climatic changes > Alberta; Climatic changes > Montana; Precipitation variability > Alberta; Precipitation variability > Montana; Paleoclimatology > Alberta; Paleoclimatology > Montana; Dendroclimatology > Alberta; Dendroclimatology > Montana; Alberta > Climate; Montana > Climate; Arctic; Pacific; Regina; Climate change; North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10294/3570; http://ourspace.uregina.ca/bitstream/handle/10294/3570/Lapp_Suzan_200261300_PhD_Geography_Fall_2012.pdf

A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Special Case Doctor of Philosophy in Geography, University of Regina, xii, 196 l. Historically, the Canadian Prairies have been highly susceptible to extreme drought and pluvial events, resulting in economic hardship. There are strong associations between large-scale circulation patterns (i.e. teleconnections), such as the low frequency Pacific Decadal Oscillation (PDO), and higher frequency El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation/Arctic Oscillation (NAO/AO), and the interannual to multi-decadal hydroclimatic variations over western North American. Archives of the longest instrumental period of record (~100 to 150 years) are unlikely to capture the full range of hydroclimatic variability (50-70 years) or enable full assessment of the links between the large-scale circulation patterns and the regional moisture conditions. Multi-centennial, seasonal paleoclimatic reconstructions were derived for the northwestern Great Plains using tree-rings located along the eastern Rocky Mountains of Alberta and Montana. The variability in these hydroclimatic reconstructions was explored on time scales of decadal to multi-decadal to assess the coherence between natural climate oscillations and the frequency, severity and duration of drought and excess precipitation. The results suggest that drought events are often associated with the positive phase of the PDO and increased ENSO variance. The association between pluvial events and the phases of the PDO and ENSO are not as clearly defined as the drought events. Due to the non-stationarity of the climate system, these historical climate trends and climate variability cannot be projected forward. However, water managers, stakeholders and policy makers are concerned how anthropogenic climate change will alter these natural variability patterns. Global Climate Models (GCMs) are the only credible tool to derive future climate ...