The purpose of the study is to investigate influences of stratospheric circulation anomalies on NCV. Using the NCEP/NCAR (daily and month mean) dataset over 1958?2010, the authors performed statistical and composite analyses on the characteristics and three dimensional structures of NCV for stratospheric northern-hemisphere annular mode anomalies. It shows that NCV has more frequent occurrences and longer duration during negative stratosphere NAM anomalies than that during positive NAM anomalies. Composite results show that NCV is stronger during negative stratospheric NAM anomalies than that during positive NAM anomalies. It is also found that during negative stratospheric NAM anomalies NCV is more closely related to downward, eastward and equatorward propagation of stratospheric anomalies, indicating that negative stratospheric NAM may enhance formation and development of NCV and lead to colder weather in Northeastern China. The results have important implications for medium range forecasting NCV in the winter season.

Two methods are applied to detect non-stationarity in time series. One is the run-test (RT) method, which depends on statistic theory; the other is a graphical method called space time-index (STI), which is a dynamical method. Three different RT methods and STI method are given to detect the non-stationarity in artificial time series with known non-stationarity and experimental turbulence time series measured in atmospheric boundary layer. The results show that the RT method which has lower accuracy is simpler and more efficient than STI. Besides comparing the merits of the STI and RT methods, the results also show that the variance RT method is the most effective to detect the non-stationarity in experimental turbulence time series among the three ones of RT methods.

The construction of exact solutions of nonlinear Schrdinger equations plays an important role in understanding the dynamic evolution of Bose-Einstein condensates. The Jacobi elliptic function expansion methodis appliedto construct the envelope periodic solutions to one dimensional Gross-Pitaevskii equation in Bose-Einstein condensates. The envelope periodic solutions can degenerate to the envelope solitary solutions under the limited condition.

A baroclinic 2-layer model, including diabatic facter, was established to analyse the effects of diabatic factor on ultra-long waves in the tropical atmosphere. The results showed that each of diabatic facters could change the characteristics of adiabatic ultra-long waves, this could be seen in two ways: 1. the stability. 2. the propagating characteristics (including propagating direction and phase velocity). Thus, a conclusion could be obtained that low-frequency oscillation, such as intra-seasonal oscillation et al., is a kind of diabatic waves generated by diabatic factors in common. This kind of diabatic waves is an important factor to generate the long-and medium range variations and short-range climatic anomalies.