에디 피드백에 대한 왼손의 법칙 및 기후 변화에 대한 적용

Abstract

In this study, scale interaction between synoptic eddies and low-frequency flow is investigated. It is demonstrated that there is a general rule, name as “Left-Hand Rule”, to reveal a role of synoptic eddy feedback onto low-frequency flow. This rule indicates that low-frequency anomalies systematically stir and deform the transient eddies in such a way that net anomalies in the eddy-vorticity fluxes are directed preferentially about 90 degrees towards their left-hand side, thus this eddy positive feedback plays a role in maintaining and prolonging low-frequency flow under the stormy atmosphere. As well as the eddy-vorticity flux, we demonstrate here that the eddy-temperature and moisture fluxes are also preferentially about 90 degrees toward the left-hand side of the low-frequency flow in the northern hemisphere. The temperature fluxes and their vertical structure play a role in constructing equivalent barotropic structure of the low frequency flow. The moisture fluxes play a role in enhancing low-frequency flow by providing eddy-induced convective instability. Finally, we show that the potential vorticity flux by synoptic eddies also follow the Left-hand rule, indicating that the eddy vorticity and temperature fluxes play a role in enhancing low-frequency flow. It is also discussed that the left-hand rule has a strong implication on the polar climate changes. The poleward shift of the Jet can bring about a polar warming and moistening by synoptic eddy feedback, corresponding to the left-hand rule.