Measurement of internal seiche in Lake Chelan, WA

The large internal seiche of the Lucerne Basin of Lake Chelan was described in Pelletier et al., 1989, in short, the rocking back and forth of the deep cold water in the Lucerne Basin. The data for this study was collected in 1986 and 1987 and showed an extreme internal seiche. During the summer of 1987 the amplitude of the rocking of the deep cold water was as much as 70 m and the period was approximately 3 days. The main goals of this study were to a) investigate the internal seiche in more detail than was possible in the 1980’s and b) determine how the seiche interacted with the sill between the Lucerne Basin and the Wapato Basin.

This study is significant to water quality of Lake Chelan in two ways. 1) Without knowing the status of the internal seiche under summer conditions, it is difficult to know the source of waters being sampled, the deep cold water versus the shallow warm water in the lake. Each of these waters typically exhibit different water quality signatures. 2) The interaction of the internal seiche with the lake bottom likely influences the transport of fine sediment, sediment distribution and water clarity in the vicinity of the narrows of Lake Chelan. Without knowledge of the seiche dynamics it will be difficult to interpret secchi depths and related water quality parameters in this part of the lake.

Raw project data will be available in 2020 by contacting [e-mail]

卢塞恩盆地湖泊切兰的大型内部涌浪现象，曾由佩利蒂埃等人在1989年的研究中进行描述，简而言之，即卢塞恩盆地深处冷水体的来回摆动。本研究的数据采集于1986年和1987年，并揭示了极端的内部涌浪现象。1987年夏季，深处冷水体的摆动幅度高达70米，周期约为3天。本研究的主要目标在于：a) 深入探究内部涌浪，其程度超越1980年代所能达到的水平；b) 确定涌浪与卢塞恩盆地与瓦帕托盆地之间的门槛之间的相互作用。本研究对湖泊切兰的水质影响显著，体现在两个方面：1) 若不了解夏季条件下内部涌浪的现状，将难以识别所采集水体的来源，即深层冷水与湖中表层暖水，这两种水体通常表现出不同的水质特征；2) 内部涌浪与湖底的相互作用可能影响细颗粒物的运输、沉积物分布以及切兰湖狭窄处的透明度。若缺乏对涌浪动力学的了解，将难以解释该区域湖中的塞奇深度及其相关的水质参数。原始项目数据将于2020年通过联系[e-mail]提供。