Climate change impact on precipitation of the Mackenzie river basin

English Abstract:

In recent decades, extreme weather events have been occurring more frequently and in greater severity worldwide possibly because of climate change impact. As a critical corridor in Canada’s Arctic transportation network, the water level of the Mackenzie River determines the capability of the northern navigation. The Mackenzie river basin (MRB) experienced relatively dry climate the summer of 2014, which could be partly attributed to the impact of climate change. The objective of this study is to evaluate the potential impact of climate change on future precipitation of the MRB. To simulate the future climate of western Canada, a regional climate model (RCM) called WRF (Weather Research Forecasting), was selected to dynamically downscale climate projections of selected global climate models (GCMs) to local and basin scales for western Canada. Surface runoff was also simulated by a Land Surface Model (LSM), Noah, coupled with WRF. WRF was set up, its configuration fine tuned, and driven with driven with ERA-Interim reanalysis data to simulate the historical climate of the MRB. WRF’s simulated resulted were validated against selected climate reanalysis dataset. After validating WRF against observed climate and hydrologic data for the climate normal period (1971–2000), we simulated future climate of the western Canada subjected to the forcing of RCP (Representative Concentration Pathway) (RCP 4.5 and RCP 8.5) projected by CanESM2 (Canada) and CCSM4 (USA) for 2050s. Based on the process of dynamic downscaling, the future amounts of precipitation in MRB were projected.