Event Title
Spatial variation of snow vapour fluxes and melt in the Coldstream Basin, Okanagan, BC
Description
The Okanagan Basin is very likely to experience increasing water stress under projected climate change scenarios as a result of lower winter snowpacks, increasing frequency of mid-winter melt events and earlier freshets, reducing the amount of water available during the summer when demand is highest. Relatively little is known about the high elevation snow that is responsible for maintaining river discharges in this region into the summer. Snow energy and mass balance processes were studied along an elevational transect of forested and open sites in the Coldstream basin in the late winter and spring of 2007 to address this knowledge gap. SWE losses to sublimation/evaporation averaged 0.6mm and 0.8mm/day for the high and mid elevation sites respectively, with maximums exceeding 3mm/day. Correlations between gravimetric and bulk aerodynamic estimates of vapour loss and melt were generally high, with the exception of warm, windy conditions, where vapour fluxes were underestimated by the standard bulk aerodynamic methods. Roughness lengths were found to be at least an order of magnitude larger than those typically used in snow energy balance studies. The vapour fluxes were placed into magnitude classes, and related to prevailing synoptic climate conditions, gathered from upper atmosphere data gathered at the Kelowna Airport.
Document Type
Event
Start Date
8-3-2008 8:00 AM
Subject - LCSH
Hydrology--Okanagan River Watershed (B.C. and Wash.); Climatic changes--Okanagan River Watershed (B.C. and Wash.); Snow--Okanagan River Watershed (B.C. and Wash.);
End Date
8-3-2008 5:00 PM
Session
Near-Surface Processes
Genre/Form
abstracts (summaries)
Type
event
Geographic Coverage
Okanagan River Watershed (B.C. and Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Language
English
Format
application/pdf
Keywords
Okanagan, hydrology, snow, sublimation, climate
Spatial variation of snow vapour fluxes and melt in the Coldstream Basin, Okanagan, BC
The Okanagan Basin is very likely to experience increasing water stress under projected climate change scenarios as a result of lower winter snowpacks, increasing frequency of mid-winter melt events and earlier freshets, reducing the amount of water available during the summer when demand is highest. Relatively little is known about the high elevation snow that is responsible for maintaining river discharges in this region into the summer. Snow energy and mass balance processes were studied along an elevational transect of forested and open sites in the Coldstream basin in the late winter and spring of 2007 to address this knowledge gap. SWE losses to sublimation/evaporation averaged 0.6mm and 0.8mm/day for the high and mid elevation sites respectively, with maximums exceeding 3mm/day. Correlations between gravimetric and bulk aerodynamic estimates of vapour loss and melt were generally high, with the exception of warm, windy conditions, where vapour fluxes were underestimated by the standard bulk aerodynamic methods. Roughness lengths were found to be at least an order of magnitude larger than those typically used in snow energy balance studies. The vapour fluxes were placed into magnitude classes, and related to prevailing synoptic climate conditions, gathered from upper atmosphere data gathered at the Kelowna Airport.