Linné Flow Centre, Department of Mechanics, KTH, S-100 44 Stockholm, Sweden.
Phys Rev Lett. 2011 Dec 23;107(26):268501. doi: 10.1103/PhysRevLett.107.268501. Epub 2011 Dec 20.
We hypothesize that the observed wave number spectra of kinetic and potential energy in the atmosphere can be explained by assuming that there are two related cascade processes emanating from the same large-scale energy source, a downscale cascade of potential enstrophy, giving rise to the k(-3) spectrum at synoptic scales and a downscale energy cascade giving rise to the k(-5/3) spectrum at mesoscales. The amount of energy which is going into the downscale energy cascade is determined by the rate of system rotation, with negligible energy going downscale in the limit of very fast rotation. We present a set of simulations of a system with strong rotation and stratification, supporting these hypotheses and showing good agreement with observations.
我们假设，通过假设存在两个源自同一大规模能量源的相关级联过程，可以解释在大气中观测到的动能和势能的波数谱，一个是位涡的向下级联，在天气尺度上产生 k(-3)谱，另一个是向下的能量级联，在中尺度上产生 k(-5/3)谱。进入向下能量级联的能量量取决于系统旋转的速度，在极快的旋转极限下，向下的能量可以忽略不计。我们提出了一组具有强旋转和分层的系统的模拟，支持这些假设，并与观测结果吻合较好。
