工程控制测量用三角测量观测平差方法

讨论典型工程控制测量中三角测量和观测方程平差的方法，这个方法的优点与传统的条件法比较通过两个检验网成果的验算来叙述。     

PRIMARY STUDY OF SULFATE AND CARBONACEOUS AEROSOLS IN BEIJING

Results of our aerosol study, performed during 1983-1984 in Beijing, demonstrate that ambient carbonaceous aerosols are derived mainly from coal combustion. Different SO, oxidation processes have been observed in summer and winter. The winter sulfate appears to be produced locally and associated with products of incomplete combustion.     

暖云雨滴大小和电荷的观测研究

本文对30次暖性阵雨的35000多个雨滴的大小和电荷量进行了测量,并根据阵雨的强度分析了电荷谱的情况。结果表明:带正电雨滴的百分比随雨滴的增大而增大,也随阵雨强度的增强而增加。雨滴电荷的分布是不对称的,正电荷的分布总是比负电荷来得宽,且当电荷值较小时以负滴为主,而当电荷值较大时,则正滴明显占优势。在一部分观测时段中,测站附近的火山爆发。它对雨滴电荷的影响是使电荷分布变窄,带大电荷的雨滴比例下降。本文用暖云中雨滴形成时离子与雨滴的相互作用的起电机制来讨论和解释上述结果。     

THE GATE SQUALL LINE OF 9－10 AUGUST 1974

A tropical squall line that passed over the ship array of the Global Atmospheric Research Programme’s Atlantic Tropical Experiment (GATE) on 9－10 August 1974 is analyzed. This squall line was similar to squall systems that passed over the GATE ship array on four other days. It began as a purely convective cloud line, then developed an associated stratiform cloud and precipitation area. The stratiform rain built up to a maxi-mum amount over a period of 8 h, then gradually diminished over a 6 h period. This stratiform rain is esti-mated to have accounted for 32% of the squall system’s total precipitation. As in other GATE squall lines, the upper-level cloud shield from which the stratiform rain fell, was advected slowly forward of the line during the system’s lifetime, the leading line of corrective clouds consisted of transient smaller-scale convective elements, which lent the line an irregular shape and pulsatory movement, and the stratiform portion of the system was characterized by the development of a mid-level mesoscale vortex similar to that seen in other GATE eases.     

Zonal and meridional circulations in the equatorialzone as deduced from the divergence field of the surface wind

The zonal and meridional circulations and their variability are examined on the basis of the surface wind data for 1950-1979. The climatological mean zonal wind and its divergence are examined in reference to the Walker Circulation. The role played by the meridional circulation in contributing to convergence of the surface wind field within the equatorial zone is emphasized. Regression coefficients are used to infer seasonal mean anomalies of divergence of the surface wind in years when the sea level pressure is 1 hPa above normal at Darwin, a condition representative of El Nino events. It is shown that anomalies in the divergence associated with the meridional wind component are primarily responsible for the heavy precipitation in the Central Pacific, while the anomalous divergence associated with the zonal wind component may cause the drought in the Western Pacific near Indonesia. A similar pattern of divergence anomalies is evident during three consecutive seasons beginning in northern summer and ending in northern winter. The reinforcement of the Hadley Circulation during El Nino episodes is noted. It is shown that the circulations over the Atlantic Ocean and Pacific Ocean are relatively uncorrelated. The interrelation between the dipole anticyclones and the meridional cir-culation over the central Pacific is discussed.     

大气环流模式中陆地水过程参数化的现状

(译者加)近年来,全球干旱等现象的模拟研究受到广泛的重视,而模拟的结果在一定程度上依赖于GCM中陆地水过程参数化的改进。这种状况促进了陆地水过程参数化的研究。本文对之进行了较系统的评述,首先回顾了GCM中现行的参数化方案,然后讨论了植被覆盖在地-气相互作用中的重要性以及这方面的研究状况,最后叙述了陆地水过程参数化中的主要困难。     

诊断在天气预报中的作用

本文指出,在天气预报日趋定量化和客观化的今天,预报工作者要避免把客观模式看成“黑盒子”。在相当长的一段时间里,仅使用定量模式可能还不足以满足天气预报的需要,必须继续运用关于大气过程的定性信息。在这当中,诊断分析是关键的步骤。     

降水系统的概念模式

雷达和卫星图象的解释是临近预报的主要内容之一。在做提前几小时的降水详细预报时,需要借助于天气尺度、中尺度现象和它们的机制对图象进行仔细的解释。本文综述了一些概念模式,这些模式描绘了热带和中纬地区的中纬度气旋、中尺度对流系统的各种表现。特别讨论了下述现象: (ⅰ)暖输送带,包括在上滑和下滑冷锋形势中具有后倾上升和前倾上升的输送带;(ⅱ)暖锋前的冷输送带;(ⅲ)出现在冷锋前低空急流边界层的与线对流相联系的窄雨带;(ⅳ)与对流层中层对流有关的中尺度宽雨带;(ⅴ)热带和中纬度飑线;(ⅵ)热带和中纬度非飑线中尺度对流系统;(ⅶ)与冷旋涡相联的次天气尺度逗点云;(ⅷ)极槽输送带和即刻锢囚(instant occlusion)。     

三种干旱指标的比较分析

测试了三种干旱指标,并讨论了它们在描述不同干旱强度的干旱期方面的性能,作了相互比较。这些指标是:雨量距平指标(RAI)、Bhalme和Mooley干旱指标(BMDI)、Palmer干旱指标(PDI)。用内布拉斯加州资料作为例子,结果表明,在检测干旱期方面,这三种指标都是有效的。分析结果认为降水是影响气象干旱的最重要的气候因素。因此,可以得出结论:在进行单站分析时,用雨量这一简单指标和比较复杂的干旱指标,在描述干旱期和干旱强度方面,效果是相同的。