This paper examined the decadal mean, seasonal cycle, and interannual variations of mean and extreme temperatures using daily temperature and relative humidity data from 589 stations over eastern China and South Korea between 1996-2005. The results show that the decadal mean Tm (mean daily mean temperature) and the TNn (minimum daily minimum temperature) increase from north to south; the opposite spatial gradient is found in the DTR (diurnal temperature range); the value of the DTR over South Korea is in- between that over North China and the mid-low Yangtze River valley; the TXx (maximum daily maximum temperature) has a unique spatial distribution, with the largest value over eastern China. The highest standard deviation (STD) is located over northern China and the TNn has the largest area coverage of the high STD. The peak of the seasonal cycle for the Tm, TXx and TNn over South Korea (August) occurs one month later than that over eastern China (July). The seasonal cycle of the DTR has two peaks (April and October); the value in the middle-lower reaches of the Yangtze River valley is larger than that in South Korea during July and August owing to the seasonal northward jump of the major monsoon rain band. The interannual variations of summertime temperature indices including the Tin, TXx, and DTR over South Korea are consistent (opposite) to that over northern (southern) China. For the wintertime temperature indices however, the variation over South Korea is consistent with that over eastern China.
Based on the full domain partition, a parallel finite element algorithm for the stationary Stokes equations is proposed and analyzed. In this algorithm, each subproblem is defined in the entire domain. Majority of the degrees of freedom are associated with the relevant subdomain. Therefore, it can be solved in parallel with other subproblems using an existing sequential solver without extensive recoding. This allows the algorithm to be implemented easily with low communication costs. Numerical results are given showing the high efficiency of the parallel algorithm.
利用LASG格点大气环流模式GAMIL1.1.0(Grid-point Atmospheric Model of IAP LASG,Version1.1.0),按照国际CLIVAR计划设计的"20世纪气候模拟"试验方案,模拟研究了包括观测海温、自然驱动和人类活动在内的各种外强迫因子对20世纪全球变暖的综合影响,发现上述外强迫因子在年际、年代际尺度上,对地表气温的演变起重要作用,20世纪30年代和自70年代开始的增暖,均是由外强迫所致.在除欧亚和北美大陆的部分区域外,外强迫对两次变暖期间的区域温度变化也有重要影响.大气内部噪音的影响,在变冷期比变暖期要强.
In this paper, a semi-discrete defect-correction mixed finite element method (MFEM) for solving the non-stationary conduction-convection problems in two dimension is presented. In this method, we solve the nonlinear equations with an added artificial viscosity term on a finite element grid and correct this solutions on the same grid using a linearized defect-correction technique. The stability and the error analysis are derived. The theory analysis shows that our method is stable and has a good convergence property.