论文标题
在差异加热的旋转环实验的光谱中，从地球流动到惯性的惯性波的过渡
Transition from geostrophic flows to inertia-gravity waves in the spectrum of a differentially heated rotating annulus experiment
论文作者
论文摘要
惯性 - 重力波（IGW）在地面大气动力学中起着至关重要的作用，因为它们在向上传播时会导致能量和动量通量。一个开放的问题是IGW在哪个程度上有助于总能量和在中尺度观察到的能量谱的扁平化。在这项工作中，我们介绍了大规模平衡流量与小规模不平衡流量之间的能量分布的实验研究。在差异加热的旋转环实验中观察到了从斜压喷射发出的弱非线性IGW。与大气光谱类似，实验动能光谱揭示了典型的细分，分为两个不同的机制，带有斜率$ k^{ - 3} $，对于小尺度而言，$ k^{ - 5/3} $。通过将光谱分离到涡流和波部成分中，就会出现在中尺度的大尺度端，实验中观察到的重力波会导致光谱扁平并提供大部分能量。在较小的尺度下，我们的数据分析表明，向前级别级联向湍流方向进行过渡，直到发生扩散过程耗散的地方。
Inertia-gravity waves (IGWs) play an essential role in the terrestrial atmospheric dynamics as they can lead to energy and momentum flux when propagating upwards. An open question is to which extent IGWs contribute to the total energy and to flattening of the energy spectrum observed at the mesoscale. In this work, we present an experimental investigation of the energy distribution between the large-scale balanced flow and the small-scale imbalanced flow. Weakly nonlinear IGWs emitted from baroclinic jets are observed in the differentially heated rotating annulus experiment. Similar to the atmospheric spectra, the experimental kinetic energy spectra reveal the typical subdivision into two distinct regimes with slopes $k^{-3}$ for the large scales and $k^{-5/3}$ for the small scales. By separating the spectra into the vortex and the wave component, it emerges that at the large-scale end of the mesoscale the gravity waves observed in the experiment cause a flattening of the spectra and provide most of the energy. At smaller scales, our data analysis suggests a transition towards a turbulent regime with a forward energy cascade up to where dissipation by diffusive processes occurs.
