The Kinetic Energy Balance of Two Summer Cyclones over the Changjiang-Huaihe Valley and Its Relations with the Large Scale Circulation

In this paper, quasi-lagrangian methos is used to calculate the kinetic energy balance and the contribution to the cross contour kinetic energy generation by the rotational and divergent wind components. Their relations with the large scale circulation are also discussed. Main conclusions include: (1) the characteristics of kinetic energy varies according to the large scale circulation; (2) the horizontal transport of kinetic energy is determined by the locations of the cyclone relative to the jet stream; (3) there is large magnitude of kinetic energy generation (destruction) by the rotational wind component near the entrance (exit) region of a stable jet stream; (4) a slowly deepening cyclone wave is associated with significant kinetic energy generation by the divergent wind in the upper and lower layers; (5) the conversion of a summer cyclone wave into a typical extratropical cyclone occurs when an upper level trough with an associated jet stream moves towards the east coast and a large amount of kinetic energy is imported into the cyclone region.