New synoptic meteorology : dynamics on baroclinic wares, medium-scale waves, and gravity wares

1.大尺度现象的资料分析：用40年的全球再分析资料研究了两半球对流层和平流层环流的年际变化。研究了大气波动对平均纬向气流维持和变化的动力作用。通过统计分析，对对流层与平流层、赤道区与中纬度地区的动力耦合问题提出了一些新的认识和问题。中小尺度现象的数据分析：利用来自中尺度雷达、无线电探空仪、预报模型和欧洲中期天气预报中心全球分析的各种数据，对平流层重力波和对流层中层波进行了研究。通过三个多星期的MU雷达特殊观测，发现平流层弱风层中存在单色惯性重力波。建立了中尺度波动的气候学，并提出了维持中尺度波动的机制。 ...更多信息 并对各波振幅进行了分析.大尺度现象的数值试验：发展了二维和三维全球大气模式，通过行星尺度气流和天气扰动之间的非线性相互作用来研究大气环流的低频变化。将动力过程划分为三种理想情况，阐明了各系统低频变化的机制：地形强迫波与平均纬向气流的相互作用;斜压扰动与平均纬向气流的相互作用;斜压扰动、强迫行星波与平均纬向气流的相互作用。中小尺度现象的理论和数值试验：在准地转框架下，对中尺度波的存在进行了理论上的考虑。中尺度波可以解释为中纬度对流层顶附近的一个中性模态，它被困在大的正位涡极大值中。此外，还成功地用高分辨率气候模式模拟了真实的重力波。对重力波的产生、传播和作用有了全面的认识。少

1. Data analyses of large-scale phenomena : Interannual variations of the tropospheric and stratospheric circulations in both hemispheres were studied with a 40-year long global reanalysis data. Dynamical effects of atmospheric waves on the maintenance and variation of the mean zonal-flow were investigated. By a statistical analysis some new findings and questions were obtained on the dynamical coupling between the troposphere and stratosphere, and the coupling between the equatorial region and mid-latitudes.2. Data analyses of small and medium-scale phenomena : Using various data from the MU radar, radiosondes, forecast models, and global analysis by ECMWF, stratospheric gravity waves and tropopausal medium-scale waves were examined. Through a special observation by the MU radar over three weeks, the existence of a monochromatic inertial gravity waves was discovered in a weak wind layer in the stratosphere. Climatology of medium-scale waves was established and mechanisms to maintain t … More he wave amplitudes were elucidated.3. Numerical experiments of large-scale phenomena : Two-dimensional and three-dimensional global atmospheric models were developed to investigate the low-frequency variations of atmospheric circulation through nonlinear interactions between planetary-scale flow and synoptic disturbances. The dynamical processes were divided into three idealized situations and the mechanisms of low-frequency variations in each system were clarified : interactions between (1) topographically-forced waves and the mean zonal-flow; (2) baroclinic disturbances and the mean zonal-flow; (3) baroclinic disturbances, forced planetary waves and the mean zonal-flow.4. Theory and numerical experiments of small and medium-scale phenomena : Based on the quasi-geostrophic framework, theoretical consideration on the existence of the medium-scale waves was made. The medium-scale waves can be interpreted as a neutral mode trapped into large positive maximum of potential vorticity around the midlatitude tropopause. Moreover, simulation of realistic gravity waves by a high-resolution climate model was succeeded. A global view of the generation, propagation and action of gravity waves was obtained. Less