A simulation of the generation of stratospheric gravity waves in upper-tropospheric jet stream over North China

Rui Yang* and Yi Liu
Key Laboratory of Middle Atmosphere and Global Environment observation,Institute of Atmospheric Physics, CAS, China

The stratospheric gravity waves (GWs) generated by subtropical jet over North China are simulated using the Advanced Research Weather Research and Forecasting (WRF-ARW) meso-scale model. The simulation can reproduce the development and structure of subtropical jet well. A strong two demensional signal of GWs is found nearby the jet stream which exist above the jet stream and propagate to the upstream of the background. GWs vary significantly with the vertical levels. There are two reasons for the weakening of GWs: the dissipation of vertical shear generated by the jet stream with the increase of height, and the existence of a quasi-zero Wind Layer in the transition layer (18~25km) of easterlies and westerlies. Meanwhile, we compare the result of WRF-ARW to the signal extracted from satellite observations to test the simulation capability of WRF-ARW. Spatio-temporal spectral is used to investigate the key feature of GWs, including the propagation　direction, wavelength and period of the jet-induced GWs. Considering the effect of topography in generating GWs, we try to remove the topography to reveal the single effect of jet stream in generating GWs.


*email: yangrui@mail.iap.ac.cn
*Preference: Poster