Downscaling the hydrological cycle in the Mackenzie basin with the Canadian regional climate model

Abstract

The Canadian Regional Climate Model (CRCM)

Autumn synoptic conditions and rainfall in the subarctic Canadian Shield of the Northwest Territories, Canada

“…Both regional climate model (Mackay et al, 1998) and gridded observation data (Lackmann and Gyakum, 1996;Stewart et al, 2000) have shown the development of an inland low with a band of precipitation 6 h after the presence of a low in the Gulf of Alaska. The band of precipitation modelled by Mackay et al (1998) was associated with a lee cyclone that developed after about 24 h and continued over the next 36 h. The band of precipitation tended to advance over the study region between 24 and 48 h after it developed. The results shown in Figure 6 and the case study of the 31 August 1998 event ( Figure 7) corroborate this temporal pattern.…”

Moisture recycling over the Mackenzie basin

“…As discussed earlier, recycling processes can have significant impacts on the surface hydrologic response (including runoff and discharge) to variations in the large-scale forcings, it is therefore of both scientific and practical interest to study moisture recycling over the MRB. Although estimates of the precipitation recycling ratio over the MRB have been included in some studies (e.g., Mackay et al, 1998), there has not been a systematic and comprehensive study of this topic for this climatologically important region. The purpose of this study is to estimate the precipitation recycling ratio as well as its temporal and spatial variability over the MRB.…”

“…Study (MAGS) program (Stewart et al, 1998). In particular, the role of recycling in producing the low precipitation and record low discharge from the basin during the 1994/95 water year (Stewart et al, this issue) will be discussed.…”

“…The hydrological processes over the MRB can thus have significant effects on the oceanic, and subsequently the atmospheric, general circulations. Due to its large area and geographical location, strong spatial and seasonal variability characterizes the basin's climate and physiographic features (Stewart et al, 1998), and processes corresponding to all terms on the RHS of Eqs (1) and (2) can play significant roles in affecting the surface hydrology of the region. The MRB is also one of the regions where the strongest climate change signals have been observed during the last few decades (Cao et al, 2001).…”

Hydrometeorological features of the Mackenzie basin climate system during the 1994/95 water year: A period of record Low Discharge

“…The evolution of the snowcover over the basin was certainly influenced by the overall temperature and precipitation characteristics (MacKay et al, 2001). Weekly snow cover fraction was deduced using a National Snow and Ice Data Center (NSIDC) dataset (Fig.…”