热带对流活动与低频波流相互作用

利用ＥＣＭＷＦ客观分析资料，使用Ｂａｔｔｅｒｗｏｒｔｈ带通滤波技术，应用诊断分析的方法研究了１９８３／１９８４和１９８６／１９８７两年冬季中纬度地区低频波流间的相互作用特征，强调了热带地区对流活动的差异对于这种相互作用的重要影响。     

一种带通滤波方法及其初步应用

本文将Barnes-Shapiro类的低通滤波方法作了改进，成为带通滤波分析方法，它具有较好的中尺度带通响应。用此方法对1980年5月和6月我国的9个中尺度云团个例作了地面要素场分析。结果表明，带通滤波后的场具有较明显的中尺度特征，其中有一些场的配置与6小时后的云团位置及强度有较好的关系。     

用滤波插值方案作气象要素场的客观分析及次天气尺度分离

Ｂａｒｎｅｓ权重法在进行网格点插值的同时，通过选择适当的滤波参数ｃ、ｇ滤去资料中短波噪音，使分析结果平稳光滑；另外可通过它构成一带通滤波器，根据实际需要分离出影响天气过程的各种尺度。本文给出Ｂａｒｎｅｓ权重法作滤波插值及带通滤波的详细步骤，并以１９８６．９．７．０８时７００ｈＰａ风场为例作了实例分析，可以看出客观分析结果与实况相符合，经带通滤波后次天气尺度（波长５００～１５００ｋｍ）表现更加明显，而这种次天气尺度波动正是夏季影响我区暴雨主要天气系统。     

华南地区大气气溶胶质量谱与水溶性成分谱分布的初步研究

利用１９８４年夏季的ＥＣＭＷＦ／ＷＭＯ逐日资料及ＯＬＲ资料，采用带通滤波方法，分析了南海对流活动对北半球中低纬大气环流的影响。结果表明，南海对流活动的低频变化对我国南方地区的大气环流有显著影响，南海对流活动首先影响印尼附近的上升支的强度，然后通过南北半球中低纬地区对流活动相互作用影响西太平洋副热带高压的强度和位置，从而影响我国南方的天气。     

近百年全球海温异常变化与长江中下游梅雨

使用Butterworth带通滤波的方法,将1885年以来全球海温和长江中下游梅雨量进行2~3年、2.5~7年、11~13年和15~20年4个时间尺度周期带的滤波,分析了二者特定周期带振荡之间的相关关系。结果表明,全球海温与长江中下游梅雨特定周期带变化之间的相关比带通滤波前的相关显著,特别是较长时间尺度的周期带的相关更显著。     

哈尔滨地区一次暴雨过程的中尺度扰动分析

利用逐日NCEP/NCAR位势高度场资料,通过Barnes带通滤波对哈尔滨地区2004年7月2日暴雨过程中高度场进行尺度分离。结果表明Barnes带通滤波方法能很好地得到常规资料不易分析出的中尺度天气系统,并分析出中尺度扰动与暴雨落区有很好的对应关系。     

用带通滤波方法分析中尺度扰动与暴雨的关系

使用带通滤波方法分析了中尺度扰动与湖北省暴雨之间的关系，得出一些有一定预报意义的暴雨中尺度扰动场概念模型。     

气象场中尺度带通滤波方法研究

关于带通滤波方法在气象场中尺度分析中的应用,有许多人进行过这方面的工作,并取得了一定的效果。尽管如此,在这方面仍有许多问题值得探讨和研究。例如,目前人们对带通滤波器的构造比较随意,究竟以什么为标准才能设计出比较合适和理想的滤波器呢?对这些问题的深入研究,将有助于带通滤波方法在中尺度分析研究中取得更为满意的效果。     

青藏高压前部突发性局地强暴雨的初步研究

本文通过对一次500hPa青藏高压前部的突发性强暴雨天气的诊断分析，揭示了暴雨产生的环境场特征。利用带通滤波方法,分析了与暴雨天气密切相关的中尺度系统及发展机理，获得了一些对业务预报有指导意义的结果。     

东亚冬季风三维环流的低频振荡特征

利用ＥＣＭＷＦ／ＷＭＯ逐日客观分析格点资料，采用带通滤波分析了冬季风环流的低频振荡特征，结果表明冬季风水平环流和垂直环流都表现出显著的准４０天振荡特征，高低层水平环流的低频变化主要受热带西太平洋和澳大利亚附近的低频涡旋系统的影响，纬向环流的低频变化表现为Ｗａｌｋｅｒ环流的加强和减弱。经向环流则表现为局地振荡特征，它的低频振荡起着联接南北半球和高低层季风环流低频振荡的作用。     

BANDPASS FILTERING ANALYSIS WITH GAUSSIAN WEIGHTING FUNCTION IN TWO-DIMENSIONAL FIELDS

This paper examines the response of the bandpass filter with Gaussian weighting function to arbitrarytwo-dimensional fields and proposes a new concept of relative response function.Based on the properties of relative re-sponse function,satisfactory weighting parameters C_1 and C_2 are obtained.By studying two cases,the procedure of us-ing structure function curves to choose the maximum response wavelength is formulated.It is shown that bandpass fil-tering offers some improvements to the analysis and forecast of mesoscale weather processes.     

A new weighting function for estimating microwave sounding unit channel 4 temperature trends simulated by CMIP5 climate models

A new static microwave sounding unit (MSU) channel 4 weighting function is obtained from using Coupled Model Inter-comparison Project, Phase 5 (CMIP5) historical multimodel simulations as inputs into the fast Radiative Transfer Model for TOVS (RTTOV v10). For the same CMIP5 model simulations, it is demonstrated that the computed MSU channel 4 brightness temperature (T4) trends in the lower stratosphere over both the globe and the tropics using the proposed weighting function are equivalent to those calculated by RTTOV, but show more cooling than those computed using the traditional UAH (University of Alabama at Huntsville) or RSS (Remote Sensing Systems in Santa Rosa, California) static weighting functions. The new static weighting function not only reduces the computational cost, but also reveals reasons why trends using a radiative transfer model are different from those using a traditional static weighting function. This study also shows that CMIP5 model simulated T4 trends using the traditional UAH or RSS static weighting functions show less cooling than satellite observations over the globe and the tropics. Although not completely removed, this difference can be reduced using the proposed weighting function to some extent, especially over the tropics. This work aims to explore the reasons for the trend differences and to see to what extent they are related to the inaccurate weighting functions. This would also help distinguish other sources for trend errors and thus better understand the climate change in the lower stratosphere.     

计算HIRS/2通道透过率的指数和模式

气象卫星HIRS/2各通道的吸收系数，透过率及权重函数与温度廓线一样随地点与时间而变化。把石广玉提出的指数和模式加上各通道仪器响应函数的修正，得出适合气象卫星HIRS/2各通道不同气体吸收系数的指数和模式，可以较快地计算HIRS/2各通道不同温度廓线下的透过率与权重函数。用修正的指数和模式计算CO2一些通道的透过率，与精确的逐线积分法的计算结果相比，CO2通道绝对差值小于0.0036；水汽1364 cm-1通道绝对差值小于0.0035。     

高,低分辨率模式对典型个例的对比预报试验

利用实时观测资料Ｔ６３模式预报产品资料，对１９９５年７－８月发生在西北地区的３次大雨、暴雨天气过程进行了高、低分痃率数值预报模式的对比预报试验。     

关于四维变分同化方法目标函数的权矩阵

本文运用概率统计理论讨论目标函数的权矩阵，证明了以误差协方差阵的逆为权矩阵的优越性，还证明了四维变分同化所得的初始场估计是渐近无偏的，同时又是渐近有效的。给出几种权矩阵模拟检验的结果，从而为选择合适权矩阵提供依据。     

Simultaneous Non-linear Retrieval of Atmospheric Temperature and Absorbing Constituent Profiles from Satellite Infrared Sounder Radiances

Based on Zeng’s theory (1974), a successive linearized form of radiative transfer equation (RTE) is derived for simultaneous retrieval of atmospheric temperature and absorbing constituent profiles from satellite infrared observa-tions. It contains the temperature component weighting function and absorbing constituent (H2O, O3, CH4 etc.) com-ponent weighting functions. All these weighting functions reach maximum at their own “optimum information levels”, and make the remote sensing equations well-conditional. Then the atmospheric profiles are derived by Newton’s non-linear iteration method. Experiments of retrieval from both TIROS-N operational High Resolution Infrared Sounder (HIRS) and the simulated Atmospheric infRared Sounder (AIRS) show an significant improvement.     

Testing of the bandpass eddy covariance method for a long-term measurement of water vapour flux over a forest

The bandpass eddy covariance method has been used to measure the turbulent flux of scalar quantities using a slow-responsescalar sensor. The method issimilar in principle to the traditional eddy correlation method but includes the estimation of high-frequency components of the flux on the basis of cospectral similarity in the atmospheric surface layer. In order to investigate the performance of the method, measurements of the water vapour flux over a forest with the bandpass eddy covariance method and the direct eddy correlation method were compared. The flux obtained by the bandpass eddy covariance method agreed with that by the eddy correlation method within ±20% for most cases, in spite of a rather slow sensor-response of the adopted hygrometer. This result supports its relevance to a long-term continuous operation, since a stable, low-maintenance,general-purpose sensor canbe utilized for scalar quantities. Oneweak point of the method isits difficulty in principle to measure the correct flux when the magnitude of the sensible heat flux is very small, because the method uses the sensible heat flux as a standard reference for the prediction of undetectable high-frequency components of the scalar flux. An advanced method is then presented to increase its robustness. In the new method, output signals from a slow-response sensor are corrected using empirical frequency-responsefunctions for the sensor,thereby extending the width of the bandpass frequency region where components of the flux are directly measured (not predicted). The advanced method produced correct fluxes for all cases including the cases of small sensible heat flux. The advanced bandpass eddy covariance method is thus appropriate for along-term measurement of the scalar fluxes.     

一阶Buterworth递归式带通滤波器技术改进方案

把一阶Ｂｕｔｔｅｒｗｏｒｔｈ递归带通滤波器应用于滑动样本,输出序列出现了振幅和位相的相对误差,为了克服这种现象给制作中长期预报带来的困难,作者通过数值试验,分析了该滤波器的误差传递特性,并设计了“拟定初值的三步滤波方案”。大量试验表明,该方案可较为有效地抑制输出序列的误差和位相飘移。     

一阶Buterworth递归式带通滤波器技术改进方案

把一阶Ｂｕｔｔｅｒｗｏｒｔｈ递归式（ＦＢＲ）带通滤波器应用于滑动样本,输出序列出现了振幅和位相的相对误差。为了克服这种现象给制作中长期预报带来的困难,作者通过数值试验,分析了该滤波器的误差传递特性,并设计了“拟定初值的三步滤波方案”。大量试验表明,该方案可较为有效地抑制输出序列的误差和位相飘移     

暴雨云团的中尺度扰动特征

本文利用高空常规资料,格距为150km,取λ_(max)=1500km的带通滤波器对长江三角洲地区的暴雨云团所处的环境场(包括风场,高度场和温度场)进行尺度分离,讨论中尺度扰动场与暴雨云团的关系。