Observations of radiatively driven convection in a deep lake
Observations of radiatively driven convection in a deep lake
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DOI：
10.1002/lno.11175
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发表时间：
2019-09-01
影响因子：
4.5
通讯作者：
Austin, Jay A.
中科院分区：
文献类型：
--
作者：
Austin, Jay A.
通过一组系泊装置和自动滑翔机对深无冰的苏必利尔湖中的辐射驱动对流进行观测，以表征该现象的空间和时间尺度。停泊观测表明，表面的不稳定性会以小时为单位逐渐形成，日出后大约 6 小时，湖底附近的水开始变暖，日落后几小时，水柱就会均匀化。滑翔机观测表明存在明显的对流烟囱，它们将温水输送到水平尺度约为数十米的深度。光猝灭的浮游植物斑块与异常温暖的海水斑块重合，提供了最近在富光带中的水的二次示踪剂，并提供了对对流烟囱垂直发展的洞察。对对流烟囱丰度的分析用于估计对流单元的横向尺度，其似乎约为 50 m。
Observations of radiatively driven convection in deep, ice-free Lake Superior from a set of moorings and an autonomous glider are used to characterize the spatial and temporal scales of the phenomenon. The moored observations show that instability builds at the surface on scales of hours, water near the bottom of the lake begins warming roughly 6 h after sunup, and the water column homogenizes a few hours after sundown. Glider observations suggest the existence of distinct convective chimneys, which carry warmed water to depth with horizontal scales on the order of tens of meters. Patches of photoquenched phytoplankton coincide with patches of anomalously warm water, providing a secondary tracer of water recently in the euphotic zone, and provide insight into the vertical development of convective chimneys. An analysis of the abundance of convective chimneys is used to estimate the lateral scale of convective cells, which appears to be on the order of 50 m.