北京降水相态判别指标及检验

为提高降水相态预报准确率,以北京南郊观象台为代表站,选取1951年1月至2011年4月逐日20时至20时出现的雨夹雪日数,统计分析其月变化特征;再选取2000-2011年10月-4月08时和20时出现的雨、雨夹雪、雪个例,使用与降水个例对应时次的地面及高空常规观测数据,统计分析各层常用气象要素在各降水相态判别中的作用,并找出主要影响因子及降水相态判别指标;应用多元回归方法,建立降水相态统计预报方程,并对方程及判别指标进行检验。结果表明：雨和雪的温度、露点平均值在低层（地面到850 hPa）有明显差异,但随着高度增加其差异逐渐减小;因雨和雪的温度露点差平均值各层差异均很小,使用温度露点差很难区分降水相态;经过对2011年11月至2012年3月出现的降水相态进行检验可知,总结出的地面温度和露点判别指标以及降水相态统计预报方程均有一定的参考价值,可为今后做降水相态预报服务提供参考依据。     

控制镇江月平均气温变化的动力系统的重建及其预报应用

本文运用镇江月平均气温一维时间序列作相空间拓展，和假定相空间状态变量随时间的演化方程含有线性项和二次非线性项，利用最小二乘法求解各项系数，保留其大差贡献较大的项，重建动力系统．并用镇江月平均气温实测值作检验．结果表明，重建的动力方程对月平均气温的演变能作出较好的描写．     

Some Possible Solutions of Nonlinear Internal Inertial Gravity Wave Equations in the Atmosphere

Ｓｏｍｅ　Ｐｏｓｓｉｂｌｅ　Ｓｏｌｕｔｉｏｎｓ　ｏｆ　Ｎｏｎｌｉｎｅａｒ　Ｉｎｔｅｒｎａｌ　Ｉｎｅｒｔｉａｌ　Ｇｒａｖｉｔｙ　Ｗａｖｅ　Ｅｑｕａｔｉｏｎｓ　ｉｎ　ｔｈｅ　ＡｔｍｏｓｐｈｅｒｅＬｉＧｕｏｐｉｎｇａｎｄＬｕＪｉｎｇｈｕａ（ＣｈｅｎｇｄｕＩ...     

参数化的多次散射雷达方程和它的反演理论 Ⅱ:反演理论

本文根据参数化的多次散射雷达方程,分析了激光多次散射对激光回波信号和一次散射雷达方程反演结果的效应,提出了迭代前向积分法和迭代后向积分法以求解参数化的多次散射雷达方程,并根据多次散射信号对云和气溶胶的前向散射相函数的高度敏感性提出了一个从双接收视场的多次散射激光回波信号,同时确定云和气溶胶消光系数分布和前向散射相函数的方法.此外,本文还根据数值试验分析了这些反演方法在地基激光雷达和空间站激光雷达两种情形下的适用性.     

STRUCTURES AND CONDITIONS OF EXISTENCE FOR A KIND OF ATMOSPHERIC MOTIONS

With the method of phase plane, the P-coordinated equation sets have been derived that include no friction without the introduction of the kdv equation and the structure of atmospheric motions, conditions for existence and movement are studied for all individual solutions. The result shows that a weak high or low pressure system isjointly affected by the atmospheric static stability, latent heating due to condensation and sensible heating for the conditions for existence, state of movement, structural features.     

Master equations for climatic parameter sets

 A data set comprising the equatorial components of global atmospheric momentum and the related mountain and friction torques is used to demonstrate the usefulness of a novel analysis technique in climate research. The technique consists in deriving a Master equation in the phase plane of a pair of climate variables on the basis of time series of this pair. The Master equation predicts changes of the pair's probability distribution in this phase plane. A mean velocity and a diffusion coefficient can be derived from the coefficients of this equation. An analysis of the dynamics of the parameter pair is based on the Master equation. The circulation of the angular momenta in the phase plane is anticyclonic with an attraction towards the origin. The diffusion is strongest close to the center of the probability density distribution of the equatorial momenta. The anticyclonic motion reflects the westward propagation of those Rossby waves which contribute to the mass term. It is found that the mountain and orographic torques induce only a small fraction of the observed changes of the angular momenta. It is essentially the impact of both the Earth's deviation from sphericity and its rotation, which induces the variability of the angular momenta. The mass and wind terms are barely related to each other in contrast to the predictions of normal mode theory. Surprisingly, however, the mountain torque and the wind terms are closely linked. Received: 13 April 2000 / Accepted: 22 February 2001     

一类奇异孤波解及其在高原低涡结构分析中的应用

文中利用相平面分析法 ,由非绝热大气运动方程组导出了与非线性重力内波有关的 Kd V方程 ,然后用直接积分法得到两类有意义的孤立波解 ,重点分析了一类具有间断点的奇异孤立波解的特征 ,初步建立了此波解与一类青藏高原暖性低涡的联系 ,讨论了高原加热和层结稳定度对高原低涡生成和移动的影响 ,并且从理论上论证了高原低涡具有与热带气旋类低涡( Tropical cyclone- like vortices)类似的涡眼和暖心结构     

伴随方程在水汽资料四维同化中的应用I.理论

由于水汽相变等过程为快过程,再考虑到水汽观测误差不服从正态分布,可以认为将水汽资料与其他观测误差进行正态分布的气象资料联合同化是一种不合适的方法.故应单独对水汽资料进行同化.在下边界为第三类边界条件下,推导了适合于数值天气预报的水汽方程的伴随方程;利用目标函数的极值性,得出了水汽的四维资料同化问题的伴随算法;证明了目标函数给出的极值点为最小值点,且是惟一的.