An eddy covariance system for measuring evaporative fluxes in the Quesnel river basin, British Columbia

在过去的世纪，二氧化碳和甲烷等温室气体的人为排放导致全球地表气温上升了约0.6°C。 随着温室气体排放的加剧，这一趋势预计在下个世纪将加速。 一些最大的环境变化将发生在高纬度和高海拔地区，那里的地表能量收支对冰雪覆盖的变化非常敏感。 因此，全球变暖将对北方山区流域（如不列颠哥伦比亚省（BC）的Quesnel河流域（QRB））的水预算产生重大影响。Quesnel河流经11，500平方公里的可变（山地到平地）地形，平均海拔1400米，它包括不列颠哥伦比亚省内陆一些最潮湿和最干燥的地区。虽然由于大气层在温度升高时保持水蒸气的能力增强，未来的降水量可能会增加，但尚不清楚额外的淡水流入陆地表面后将如何分配。我的研究计划的目标是获得和保持一个长期的QRB的水预算条款的气候，并探讨气候变率和变化对水通量，包括蒸发的影响。该提案寻求为涡动相关系统提供资金，该系统将测量风速和水蒸气的三维波动，并从中推导出蒸发通量。该系统将补充QRB现有和正在开发的观测网络，并为QRB水循环数值模拟的验证提供关键数据。很好地理解气候变异性和变化对QRB水预算的作用至关重要，因为它是弗雷泽河的主要支流，构成太平洋鲑鱼的主要产卵区，并支持积极的伐木，农业和旅游业，以及其他商业活动。

The anthropogenic emission of greenhouse gases such as carbon dioxide and methane has caused global surface air temperatures to rise by about 0.6°C during the past century.  This trend is expected to accelerate in the next century as greenhouse gas emissions intensify.  Some of the greatest environmental changes will be in high-latitude and high altitude regions where the surface energy budget is highly sensitive to modifications in snow and ice covers.  Global warming will therefore have significant repercussions on the water budget of northern mountainous watersheds such as the Quesnel River Basin (QRB) of British Columbia (BC). The Quesnel River drains an area of 11,500 square kilometres of variable (mountainous to flat) terrain at a mean elevation of 1400 m, and it encompasses some of the wettest and driest areas of BC's interior. Although future precipitation is likely to increase owing to the enhanced capacity of the atmosphere to hold water vapour at warmer temperatures, it is unknown how the additional input of freshwater will be partitioned after falling on the land surface. The goals of my research program are to obtain and maintain a long-term climatology of water budget terms for the QRB and to explore the effects of climate variability and change on water fluxes including evaporation. This proposal seeks funding for an eddy covariance system that will measure 3-dimensional fluctutations in wind speed and water vapour from which the evaporative flux will be deduced. This system will complement the existing and developing observational network in the QRB and provide critical data for the validation of numerical simulations of the QRB water cycle. A good understanding of the role of climate variability and change on the QRB water budget is critical since it is a major tributary of the Fraser River, constitutes a major spawning area for Pacific salmon, and supports active logging, agricultural, and tourism industries, among other commercial activities.