气候变化领域集成服务门户(CCPortal): Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake

CCPortal

DOI	10.1029/2020JC016095
	Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake
	Reiss R.S.; Lemmin U.; Cimatoribus A.A.; Barry D.A.
发表日期	2020
ISSN	21699275
卷号	125 期号:8
英文摘要	Combining field measurements, 3-D numerical modeling, and Lagrangian particle tracking, we investigated wind-driven, Ekman-type coastal upwelling during the weakly stratified winter period 2017/2018 in Lake Geneva, Western Europe's largest lake (max. depth 309 m). Strong alongshore wind stress, persistent for more than 7 days, led to tilting and surfacing of the thermocline (initial depth 75–100 m). Observed nearshore temperatures dropped by 1°C and remained low for 10 days, with the lowest temperatures corresponding to those of hypolimnetic waters originating from 200 m depth. Nearshore current measurements at 30 m depth revealed dominant alongshore currents in the entire water column (maximum current speed 25 cm s−1) with episodic upslope transport of cold hypolimnetic waters in the lowest 10 m mainly during the first 3 days. The observed upwelling dynamics were well reproduced by a 3-D hydrodynamic model (RMSE 0.2°C), whose results indicated that upwelled waters spread over approximately 10% of the lake's main basin surface area. Model-based Lagrangian particle tracking confirmed that upwelled waters originated from far below the thermocline, that is, >150 m depth, and descended back to around 150–200 m depth over a wide area after wind stress ceased. Observational and particle tracking results suggest that wintertime coastal upwelling, which can occur several times during winter, is an overlooked transport process that is less sensitive to the effects of global warming than convective cooling. It can provide an effective but complex 3-D pathway for deepwater renewal in Lake Geneva, and other large, deep lakes with a sufficiently long wind fetch. ©2020. The Authors.
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186764
作者单位	Ecological Engineering Laboratory (ECOL), Faculty of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
推荐引用方式 GB/T 7714	Reiss R.S.,Lemmin U.,Cimatoribus A.A.,et al. Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake[J],2020,125(8).
APA	Reiss R.S.,Lemmin U.,Cimatoribus A.A.,&Barry D.A..(2020).Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake.Journal of Geophysical Research: Oceans,125(8).
MLA	Reiss R.S.,et al."Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake".Journal of Geophysical Research: Oceans 125.8(2020).