全球变暖的新观点──日最高、最低温度的非对称变化趋势

北半球（南半球）50％（10％）以上的陆地（占全球陆地的37％）的月平均最高、最低温度资料表明：1951～1990年最低温度以3倍于最高温度的速率上升（0．84℃／0．28℃），温度日较差的减小值近似于平均温度的升高值，在所有季节及本文研究的大部分区域均可观测到这种非对称性。日较差的减小与云量的增加有一定的关系。此外，许多大气和地面边界条件也不同程度地影响着最高、最低温度。而观测到的目较差变化与大尺度气候强迫（如硫酸盐气溶胶、温室气体或生物燃烧（烟）的人为增加）的关系仍处于探索阶段。尽管如此，日较差减小这一观测事实，无论在理论上还是实际上都具有明显的重要性。     

一个高分辨对流层物质交换模式

在区域酸沉积模式(RADM)基础上,设计了一个高分辨对流层(TL)物质交换模式(EM3)。EM3在以下五个方面明显不同于RADM:第一,增加行星边界层(PBL)的垂直网格层次;第二、TL内考虑分层的垂直涡旋扩散系数型;第三,使用TL内分层的水平涡旋扩散系数型;第四,采用包含有植物冠层垂直结构影响的新干沉积速度型;第五,使用数值扩散小的二阶矩守恒平流格式.用EM3和RADM对OSCAR Ⅳ实例作对比模拟,结果表明EM3能更好地预测出TL内的三维物质分布规律,在同样条件下,两模式预测的PBL低层中心浓度比值均大于1.8,最大值可大于3。     

ELIMINATING COMPLEX EIGENVECTORS AND EIGENVALUES IN MULTIWAY ANALYSES USING THE DIRECT TRILINEAR DECOMPOSITION METHOD

The direct trilinear decomposition method(DTDM)is an algorithm for performing quantitative curveresolution of three-dimensional data that follow the so-called trilinear model,e.g.chromatography-spectroscopy or emission-excitation fluorescence.Under certain conditions complexeigenvalues and eigenvectors emerge when the generalized eigenproblem is solved in DTDM.Previouspublications never treated those cases.In this paper we show how similarity transformations can be usedto eliminate the imaginary part of the complex eigenvalues and eigenvectors,thereby increasing theusefulness of DTDM in practical applications.The similarity transformation technique was first used byour laboratory to solve the similar problem in the generalized rank annihilation method(GRAM).Because unique elution profiles and spectra can be derived by using data matrices from three or moresamples simultaneously,DTDM with similarity transformations is more efficient than GRAM in the casewhere there are many samples to be investigated.     

MULTIVARIATE SELECTION OF VARIABLES IN INDUSTRIAL QUALITY CONTROL:OPTIMIZING AVIATION FUEL FINAL CONTROL

This paper deals with a typical question encountered in all industrial analytical laboratories:are all thetests performed in the laboratory to characterize the final product really necessary?In this work the cross-validation technique,Procrustes rotation techniques and statistical variable selection have been used toreduce the 26 initial British Petroleum and ASTM kerosene specification tests to ten'essential'ones.Statistical as well as chemical considerations were used to select the optimum subset of original variablesto be retained from all the possible ones.     

以实况资料对比研究各种裸地蒸发公式

引言鉴于土壤水不是自由水,裸地蒸发过程非常复杂。土表和大气间水汽转化量不仅取决于较深土层向上传输水分的能力,还受紧贴地表处土壤水发生汽化的薄土层中水汽向外扩散能力的影响。同时,土壤水文特征曲线的强非线性也要求表达上述界面处质量、热量转化的数值模式要非常全面,对此可采用近界面的垂向分辨力(约1 mm)。     

一种机载冰粒子探测仪器

研制了一种在风暴中探测冰粒子的简单机载仪器.虽然目前已有的精密探测仪器能够获得大气冰粒子的图象,但是用这些资料确定的粒子浓度的空间分辨率,由于采样面积小而受到限制.本文讨论的冰粒子探测器可以实时指示云中及其附近冰晶的存在,并且提供了一种测量冰粒子浓度的近似方法,这种方法具有很好的空间分辨率.该仪器结构简单,价格便宜;曾用5个夏天的时间在新墨西哥州的雷暴中对其进行了试验.     

Sensitivity of medium-range weather forecasts to the use of reference atmosphere

In this paper, the authors develop the earlier work of Chen Jiabin et al. (1986). In order to reduce spectral truncation errors, the reference atmosphere has been introduced in ECMWF model, and the spectrally-represented variables, temperature, geopotential height and orography, are replaced by their deviations from the reference atmos-phere. Two modified semi- implicit schemes have been proposed to alleviate the computational instability due to the introduction of reference atmosphere. Concerning the deviation of surface geopotential height from reference atmos-phere, an exact computational formulation has been used instead of the approximate one in the earlier work. To re-duce aliasing errors in the computations of the deviation of the surface geopotential height, a spectral fit has been used slightly to modify the original Gaussian grid-point values of orography.A series of experiments has been performed in order to assess the impact of the reference atmosphere on ECMWF medium- range forecasts at the resolution T21, T42 and T63, The results we have obtained reveal that the reference atmosphere introduced in ECMWF spectral model is generally beneficial to the mean statistical scores of 1000-200 hPa height 10-day forecasts over the globe. In the Southern Hemisphere, it is a clear improvement for T21, T42 and T63 throughout the 10-day forecast period, In the Northern Hemisphere, the impact of the reference atmos-phere on anomaly correlation is positive for resolution T21, a very slightly damaging at T42 and almost neutral at T63 in the range of day 1 to day 4. Beyond the day 4 there is a clear improvement at all resolutions.     

GPS天线安置方法和误差来源

本文阐述了天线准确定位的重要性，提出了影响天线相位中心与测站标志之间准确关系的误差来源，也提出了能够减少误差，检测粗差的外业方法和设备改进意见。     

分级统计图分级选择一般概念的研究

分级统计图分级的确定问题已有大量的文献讨论过。奇怪的是我们至今还没有提出一个分级选择的一般概念。七年前,I.S.EVANS曾写道:“分级间隔的选择,强烈地影响着由地图产生的视觉印象,但是现在还完全是制图中的一个混乱的分支。”看来,这个问题还需要一些深入细致的分析和适当的定向研究。在地图制图学手册中,可以区分出两种分级确