BL Lac天体AO 0235 164在5 GHz上的VLBI观测

应用５ＧＨｚＶＬＢＩ技术在历元１９９７.１２的观测结果,给出ＢＬ　Ｌａｃ天体ＡＯ　０２３５＋１６４在毫角秒尺度上的最新图像．该致密天体的射电结构由一个亮核所支配,另外在东北和西南方向各存在一个相对较弱的子源,其中东北方向的子源要比西南方向的明显得多.模型拟合结果显示,该源的喷流位置角为６６.４°,该数值超过以往的任何一次观测结果．根据流量密度随时间的变化关系,我们发现ＡＯ０２３５＋１６４在波长６ｃｍ上可能存在两种周期性的变化,即１—２年的短周期性变化和３－５年的长周期性变化这两种周期性的变化可能是由于喷流的爆发和旋转两种效应共同作用的结果．     

射电源AO 0235＋164不同波段之间的相关时延分析及谱指数演化

详细介绍了由Edelson和Krolik提出的离散相关分析方法，该方法比较适合于因天文观测的不规则性而引起的时间分布不均匀的不同波段之间流量的相关分析，取两种极端的情况（完全相关和完全不相关）对该方法进行了测试，结果表明这是一种比较切实可行的方法。利用它，对AO0235＋164在4个波段上流量变化作相关性分析，结果表明，AO 0235＋164在5GHz,8GHz,14.5GHz和光学BI皮段的辐射之间存在着明显的相关性，高频波段的流量变化早于低频波段的流量变化，表明这些波段的辐射（从射电到光学）可能来源于相同的辐射机制，或者辐射是相关的，另外发现，谱指数随着时间而发生变化，这种变化在5GHz 8GHz和14．5GHz之间多表现为逆谱的形式，种种迹象表明AO 0235 164的射电爆发可能是和激波的形成有关，多波段的频谱分析和频谱演化研究可能是揭示这种关系的有效途径。     

基于AO的钻孔柱状图的绘制

本文针对传统手工绘制钻孔柱状图普遍存在的成图慢、效率低,难以满足实际生产的需要等许多不足之处而开发的一个应用程序。在ArcMap内置的VBA环境下调用AO的一些接口函数完成柱状图的绘制,然后调用岩层符号化功能模块,对柱状图进行填充处理,应用起来非常方便。     

Symbian OS中事件驱动多任务的研究

首先对当今最主要的智能手机操作系统Symbian0S进行简单介绍，然后针对手机终端这一特殊硬件设备上的应用，对Symbian0S中的事件驱动多任务进行分析研究，通过对利用线程实现异步操作和AO（ActiveObject）实现异步操作进行比较，得出AO是SymbianOS中事件驱动多任务的最佳选择的结论，最后结合在实际中的应用展示了如何使用AO包装异步服务。     

Principal Modes of Summertime Zonal-Mean Flow and Their Connections with the AO and ENSO

The NCEP/NCAR reanalysis data have been employed to diagnose variations of the zonal mean flow in boreal summer. Two leading EOF modes are found to dominate the spatial and temporal changes of the summertime zonal mean winds in the troposphere. EOF1 shows the distribution of zonal-mean flow anomalies with higher variance in the North Polar Region, whereas the EOF2 shows the distribution of zonal-mean flow anomalies with higher variance in tropical and extra-tropical regions. The EOF1 and EOF2 have respectively the periodicities similar to those of AO and ENSO. Significant lag correlations have been found between EOF1 and ENSO, and between EOF2 and AO, in the seasons including spring, autumn, and winter. However, no significant correlations have been found between EOF1 in summer and ENSO in any other seasons, and between EOF2 in summer and AO in other seasons, no matter how big the lag that represents number of seasons has been set. These results suggest that the principal modes of summertime zonal mean flow could be statistically separated from each other. Hence, EOF1 and EOF2 are physically related to the AO and ENSO respectively. A theory called quasi-geostrophic non-acceleration theorem has been used to partly explain the possible mechanisms of the maintenance of the two principal modes. The composite differences of the divergence of Eliassen-Palm flux （E-P flux） between positive and negative years as obtained from the time series of EOF1 and EOF2 display the distributions that contribute to the zonal mean wind anomalies represented by EOF1 and EOF2, respectively. The planetary other than the synoptic waves dominate the behaviors of the E-P fluxes, suggesting the crucial role of the planetary waves in the maintenance of the zonal mean flow anomalies. The residual circulation as well as the friction, which cancel the divergence of the E-P flux, also play an important role in some places. These results are very helpful for our better understanding how the anomalous zonal mean flows maintain and how the ENSO and AO influence the global climate variations.     

Modulation of the Arctic Oscillation and the East Asian winter climate relationships by the 11-year solar cycle

The modulation of the relationship between the Arctic Oscillation (AO) and the East Asian winter climate by the 11-year solar cycle was investigated.During winters with high solar activity (HS),robust ...     

耦合模式对冬春季节南、北极涛动的季节气候预测能力研究

研究评估了耦合气候模式对冬、春季北极涛动(AO)和南极涛动(AAO)的预测效能。结果表明,模式对于北极涛动和南极涛动的模拟能力都是比较强的,其中,对冬季的模拟能力要强于春季。冬季,几乎所有的模式都能很好地模拟出对流层内北极涛动的空间分布形态特点,空间相关系数很高。春季,大部分模式的模拟结果仍然是比较好,与再分析资料结果的空间相关性比较高。对于南极涛动,模式在全年对流层各个层次上都能比较好地刻画其空间分布,且模式在850hPa等压面上的空间模拟效能要稍强于海平面。相对来说,冬季的模拟效果也稍强于其他季节,但是,差异不显著,模式与模式的差别也比较小。另外,模式对于北极涛动和南极涛动的时间序列模拟能力有限,时间序列相关系数只有少数几个模式达到显著性水平。     

A NORTHERN HEMISPHERE ANNULAR MODE AS THE COMBINATION OF THE NAO AND THE PNA

This paper demonstrates that an annular mode can be constructed from the combination of the North Atlantic Oscillation (NAO) and the Pacific/North American (PNA) patterns. The quasi-annularity, meridional dipole and vertical barotropy of the constructed annular mode resemble those of the Atlantic Oscillation (AO) pattern. It is also a dominant mode in terms of the variance contribution. Moreover, its temporal correlation with the AO is quite strong. This new annular mode has the advantage over the AO in that it incorporates a large portion of the PNA and makes the center of action in the Pacific stronger and more physically relevant than that of the AO. Or, more generally, it may be regarded as a physical mode unlike the AO. The results of this study also indicate the NAO–PNA perspective contains most of the information of the AO, whereas the AO perspective only contains about half of the information of the NAO-PNA. Consequently, the NAO–PNA perspective is regarded by the authors to be more comprehensive than that of the AO.     

关于北半球准定常行星波年际变化的资料分析和数值模拟

利用NCEP/NCAR再分析资料和大气环流模式(CCSR/NIES AGCM Ver.5.6), 对北半球冬季准定常行星波活动的年际变化进行了分析和模拟.基于以前对EP通量散度的遥相关分析, 作者将EP通量散度的EOF第一分量时间序列T1定义为年际变化指数.对应于T1的高指数, 在对流层和平流层低层, 准定常行星波更多地折向赤道传播, 从而在对流层出现一个EP通量散度的偶极子型异常, 这一形势主要来自2波和3波的贡献; 而折向高纬度经极地波导向上传播的行星波活动减弱了, 在高纬度产生异常辐散, 这一形势主要来自1波和2波的贡献.相关和回归分析发现, 准定常行星波的年际变化与北极涛动有密切联系, 与T1对应的纬向平均流场以及位势高度场的异常分布都与北极涛动下的异常形势非常相似.利用大气环流模式模拟的结果显示, 模式在对流层可以很好地模拟准定常行星波的年际变化以及北极涛动形势, 并且二者同样密切相关.但是模式还不能很好地模拟行星波经极地波导向平流层传播的年际变化, 对可能的成因也进行了探讨.     

西南地区冬季气候异常的时空变化特征及其影响因子

利用1961-2010 年的多种观测资料,对西南地区冬季气候异常的时空演变特征及其影响因子进行了分析。结果表明：西南地区冬季气温变化主要存在全区一致和东、西部反位相两种模态,这两种模态均存在显著的年代际变化。全区温度的一致变化与东亚冬季风的异常有关,东、西反位相的变化与西太平洋副热带高压和冷空气的异常活动有关。冬季降水异常主要表现为全区一致的变化特征。北半球环状模(NAM,AO) 和ENSO对西南地区气温没有显著的影响。当NAM偏强(弱) 时,西南地区降水偏多(少)。El Niño 年,西南地区降水一致偏多;La Niña 年,西南地区中部降水偏多,东、西部降水偏少。2010 年冬季西南地区的干旱更有可能是由NAM异常引起的,而不是El Niño。