Determining Near‐Bottom Fluxes of Passive Tracers in Aquatic Environments
Determining Near‐Bottom Fluxes of Passive Tracers in Aquatic Environments
复制标题
确定水生环境中被动示踪剂的近海底通量
DOI：
10.1002/2017gl076789
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
D. McGinnis
中科院分区：
文献类型：
--
作者：
Cynthia E. Bluteau;G. Ivey;D. Donis;D. McGinnis
在水生系统中，涡动相关法（ECM）提供了沉积物-水界面附近的垂直通量测量。ECM以高采样率（> 1 Hz）独立测量湍流垂直速度w′和湍流示踪剂浓度c′，以从其时间平均协方差获得垂直通量w′c′ ′。这种方法需要识别和解决所有与流动相关的时间（和长度）尺度对w′c′ ′ ′的贡献。随着能量流的增加，我们证明了ECM目前的技术无法解决最小的通量贡献尺度。为了避免这些困难，我们表明，对于被动示踪剂，如溶解氧，w′c′ ′可以通过两个标量的估计来测量：湍流动能耗散率ε和示踪剂方差耗散率χc。将这种方法应用于实验室和现场观测表明，新方法可以很好地解决w′c′ ′问题，并且可以在ECM无法使用的更高能量流中提供通量估计。
In aquatic systems, the eddy correlation method (ECM) provides vertical flux measurements near the sediment‐water interface. The ECM independently measures the turbulent vertical velocities w′ and the turbulent tracer concentration c′ at a high sampling rate (> 1 Hz) to obtain the vertical flux w′c′¯ from their time‐averaged covariance. This method requires identifying and resolving all the flow‐dependent time (and length) scales contributing to w′c′¯ . With increasingly energetic flows, we demonstrate that the ECM's current technology precludes resolving the smallest flux‐contributing scales. To avoid these difficulties, we show that for passive tracers such as dissolved oxygen, w′c′¯ can be measured from estimates of two scalar quantities: the rate of turbulent kinetic energy dissipation ε and the rate of tracer variance dissipation χc. Applying this approach to both laboratory and field observations demonstrates that w′c′¯ is well resolved by the new method and can provide flux estimates in more energetic flows where the ECM cannot be used.
影响因子：
4.9
作者：
L. Rovelli;M. Dengler;M. Schmidt;S. Sommer;P. Linke;D. McGinnis
通讯作者：
L. Rovelli;M. Dengler;M. Schmidt;S. Sommer;P. Linke;D. McGinnis