Data Sources
Three instrumented headwater research basins located in the northern
North American Cordillera are used to simulate potential hydrological
responses to warming and precipitation changes; Wolf Creek, Yukon
Territory, Canada; Marmot Creek, Alberta, Canada; and Reynolds Mountain
East (hereafter Reynolds Mountain) catchment, Idaho, USA (Figure 1). The
availability of long-term data from multiple hydrometeorological
stations at different elevations in each basin, makes these basins
uniquely suitable case studies for conducting sensitivity analysis on
hydrological processes. High quality measurements of hourly air
temperature, relative humidity, wind speed, incoming shortwave
radiation, precipitation, and streamflow discharge for each basin were
used. Consistent with the Ideal Gas Law, relative humidity was held
constant to allow water vapour pressure to change with temperature. The
forcing data are publically available (Wolf Creek: Rasouli et al.,
2019c; Marmot Creek: Fang et al., 2019; Reynolds Mountain: Reba et al.,
2011).
All three basins are snow-dominated under the current climate and are
partially covered by coniferous forest at lower altitudes: Wolf Creek
has spruce and pine forests, Marmot Creek has larch, fir, spruce, and
pine forests; and Reynolds Mountain has fir, pine, and aspen forests.
All elevations in Wolf Creek and the high elevations in Marmot Creek are
very cold. A cold snow season with high precipitation leads to a long
winter at high elevations in Marmot. High wind speeds in in the alpine
zones of all three basins redistribute snow by wind transport and result
in blowing snow sublimation losses. Needleleaf canopy snow interception
and sublimation losses are important in all three basins. Air
temperatures of the forested elevations in Wolf Creek are lower than for
the alpine zone in winter, due to strong inversions in the Yukon River
Valley. In contrast, Reynolds Mountain and low elevations in Marmot
Creek have warmer air temperatures with fewer freezing days, making
these more sensitive to warming.