Articles | Volume 16, issue 8
Research article
19 Apr 2016
Research article |  | 19 Apr 2016

Characteristics of gravity waves generated in the jet-front system in a baroclinic instability simulation

Young-Ha Kim, Hye-Yeong Chun, Sang-Hun Park, In-Sun Song, and Hyun-Joo Choi

Abstract. An idealized baroclinic instability case is simulated using a  ∼  10 km resolution global model to investigate the characteristics of gravity waves generated in the baroclinic life cycle. Three groups of gravity waves appear around the high-latitude surface trough at the mature stage of the baroclinic wave. They have horizontal and vertical wavelengths of 40–400 and 2.9–9.8 km, respectively, in the upper troposphere. The two-dimensional phase-velocity spectrum of the waves is arc shaped with a peak at 17 m s−1 eastward. These waves have difficulty in propagating upward through the tropospheric westerly jet. At the breaking stage of the baroclinic wave, a midlatitude surface low is isolated from the higher-latitude trough, and two groups of quasi-stationary gravity waves appear near the surface low. These waves have horizontal and vertical wavelengths of 60–400 and 4.9–14 km, respectively, and are able to propagate vertically for long distances. The simulated gravity waves seem to be generated by surface fronts, given that the structures and speeds of wave phases are coherent with those of the fronts.

Short summary
We investigated the characteristics of atmospheric gravity waves that are generated in a baroclinic life cycle simulation using a high-resolution global model. We analysed the spatiotemporal scales, vertical-propagation aspects, and sources of the gravity waves as well as their phase-velocity spectrum. The wave characteristics investigated in this study are crucial information for parameterizing gravity waves in large-scale models.
Final-revised paper