屯溪地区巨盐核浓度分布特点

1981年6—7月安徽省屯溪地区巨盐核观测的结果表明:1.直径2微米左右的巨盐核可能对屯溪夏季积状云中一些初始大云滴的形成起重要作用;2.屯溪地区的巨盐核主要源地是海洋,该地的巨盐核浓度与风向、风速以及天气背景密切相关.     

我国东部巨盐核分布及盐碱土源的初步探讨

从盐核地区分布的观点来看,盐核源地和气象条件对盐核的分布和变化都是很重要的,关于大气盐核与气象条件和海洋源地的关系,过去已有较多研究,而对陆上源地的研究却很少。在我国北方和邻国地面复盖着广阔盐碱土,它如同海面,在风的作用下,将土壤盐粒带入空中大气并扩散传播,从而影响我国东部盐核分布。本文利用我国东部地面和高空巨盐核观测资料,结合地面盐核源地和850hpa气     

热带海洋上空的云

云状、云量、云的形成和演变,直观地反映了当时大气的运动、大气稳定度以及空气中的水份状况。同时也是预示未来天气变化的重要征兆。本文使用近年我国远洋气象调查期间拍摄的云图照片和观测资料,介绍太平洋低纬地区经常出现的典型云状,试对热带海洋上空云系形成和变化的一些特点作初步探讨。 一、热带海洋上常见的云状 在海洋上,海面比较平滑,没有地形起伏造成的空气抬升;水面的热力性质比较均匀,低空没有强烈的湍流活动(洋流和近岸区除外)。但是海面上水汽充足,空气湿度很大,特别是热带洋面上,经常处于高温高湿的赤道气团或者热带辐合带控制之下,低层大气中积累了大量不稳定能量。在热力及天气系统(扰动)等影响下,对流最容易发展。因此,热带洋     

亚马逊上空的烟雨云

人们观测到亚马逊森林大火的浓烟减小了云滴的大小,使降水产生延迟。因为清洁云在云底以上1．5km处就可以产生降水,而被污染的云中这个高度要抬升到5km以上．在火成云中就要到7km以上了。云中低层被抑止的降雨和气溶胶沉降使得水份和烟尘向高层输送,高层的云就像能卸下很多污染物的‘烟’。在抬高了的降雨启动高度上,由于相变触发的上升气流导致强的雷雨、大雹以及其他类似的云体突破云顶进入平流层,在平流层沉降的污染物和水汽的辐射效应对气候系统有深刻的影响。大气中激发的风暴在更高层释放出潜热,这就从本质上影响了区域和全球的环流系统。这些过程共同影响了水份循环、大气中污染物的分布以及大气环流的动力学特征。     

青藏高原上空云的初步分析

根据1979年青藏高原气象科学实验期间,青藏高原上6个热源观测站的云量和云状观测资料,对青藏高原上空的云,特别是对流云的月际变化、日变化、地理分布与青藏高原雨季的关系进行了初步分析。     

江淮地区大气盐核分布特征的初步分析

一测量大气盐核对研究暖云降水有着十分重要的意义。1980年6—7月我们在安徽省利用人工降雨飞机进行了大气盐核的观测,初步得出了江淮地区大气盐核的浓度、大小及其垂直、水平分布上的一些特征。本文盐核资料均是利用飞机云滴取样器取样、由斑点法进行盐核的检测而得来的。     

利用全天空数字图像对北京上空云况分布特征的试验分析

利用最新获取的近两年北京上空全天空数字图像资料对云况分布做统计分析,以获得云的分布特征。工作中将图像分为9个扇区和16个环区分别进行分析,从结果看,无云(云量<1)与全天空有云天气(云量>9)情况明显占优,平均各占总量的36%,46%。除去系统误差及计算所带来的误差发现,两年中北京上空多以晴好天气(包含薄卷云)和阴天为主。上空西北部云的分布略显偏多,头顶上空云的出现概率较其他位置低,并有随天顶角增大概率增大的趋势。     

北冰洋上空云辐射作用的年变程

1 引言云通过把太阳辐射反射回太空和减少射出长波辐射损失对地球-大气系统辐射平衡进行强烈的控制。根据大气顶部(TOA)的净辐射定义,太阳辐射和长波放射作用的方向相反。这些作用中每一种作用本身都很大,但合并作用通常较小,而且主要取决于纬度、云的特性和海表状况。     

On the relative role of sea salt cloud condensation nuclei (CCN)

Contrasts between cloud condensation nuclei (CCN) spectral volatility (thermal fractionation) measurements in two aircraft field projects provide insight into the relative contribution of sea salt. During the much more cloudy Rain in Cumulus over the Ocean (RICO) project there was a high correlation coefficient (R) between refractory (non-volatile) CCN concentrations (N_CCN) and horizontal wind speed (U), especially for low supersaturation (S) N_CCN, whereas this R was significantly lower in the nearly cloud free Pacific Aerosol Sulfur Experiment (PASE) project. Volatile N_CCN at all S were uncorrelated with U. Ambient particle concentrations over a broad range of large sizes displayed consistently high R with U in both projects that was similar to the R of refractory N_CCN with U in RICO. The size range of this high R extended down to 0.2 μm in RICO but only down to 9 μm in PASE. In both projects particle concentrations smaller than these respective sizes were highly correlated with N_CCN, at all S in PASE, but mainly with N_CCN at high S in RICO. In each project N_CCN at all S was uncorrelated with all ambient particle concentrations larger than these same respective sizes. N_CCN at all S was also uncorrelated with U in both projects. The contrast in cloudiness between the two projects was responsible for many of the differences noted between the two projects. The results indicate that the effects of clouds on N_CCN play a major role in the relative influence of sea salt on N_CCN and ultimately on climate. Sea salt is a minor component of maritime CCN except at high wind speeds especially at low S.     

The preliminary syudy of medium-scale cloud clusters over the Changjiang basin in summer

It is shown that the medium scale cloud cluster is u major one of precipitation systems from analysing the rainstorms along the Changjiang River during the plum rain period of 1980-1983. The medium-scale cloud clusters do not always correspond to the moving vortex, but they are in good agreement with the convergence center for the divergent component of wind at 850 hPa. The favourable environmental conditions for the genesis and development of medium-scale cloud cluster, such as the large-scale circulation situation, patterns of temperature and moisture, potential instability, and the structure of cloud cluster are given. A model on large seaie clond pattern for the genesis of medium scale cloud cluster is presented.     

我国东部(30°N)从海岛到陆地巨盐核观测

1983年5月和8月在普陀(海岛)、宁波(沿海)和建德(内陆)三地同时进行了巨盐核的定时观测,取到样品1420份。三测站都位于纬度30°N左右,普陀到建德相距约300公里。观测结果表明:巨盐核主要来自海上;巨盐核浓度与天气背景、风向风速和潮汐现象等有关。并且还讨论了巨盐核浓度的大小分布、日变化规律以及巨盐核的水平输送等问题。     

河北地区秋季气溶胶飞机探测资料分析

利用河北省2005-2007年秋季不同天气(晴、有云、雾、降水)条件下气溶胶飞机观测资料和宏观天气资料,综合分析了河北地区不同天气、不同高度、不同城市大气气溶胶的分布特征.分析结果表明:2006- 2007年探测的气溶胶小粒子平均直径均在0.180μm以上,比2005年秋季的粒子尺度大0.05 μm左右.非降水天气下近...     

内外网物理隔离的简便方法

目前内部局域网与外部互联网互联是发展必然。而如何真正的保护内网的安全，保证内部资料，不受外网攻击或窃密，是网络管理的重要工作。只有将内网与外网进行物理隔离才能做到这点。物理隔离技术主要是通过隔离设备让内网和外网互联互通。物理隔离的主要特征，是内网与外网永不直接连接。物理隔离网闸是目前唯一能解决上述问题的安全设备。在基层局域网工作站利用双系统、双网卡同样可达到内外网物理隔离作用，节约、方便、易行。     

Technique for studying the chemistry of cloud condensation nuclei

When clouds are formed from water, ethanol or cyclohexane the relation between numbers of CCN activated over the range of supersaturations 0.25–1.25% can provide data on the chemistry of these very small, relatively numerous and environmentally important particles.     

Interrelation between variations of condensation nuclei concentration and cloud spectrum

The characteristics are studied of warm cloud mediums (size spectra, concentration, etc.) formed in the cloud chamber of the volume of 3200 m³ at adiabatic expansion of the humid air and at the variations of condensation nuclei concentration within the limits of 50–500 times from the initial one. To remove the nuclei, the volume electrostatic technique was used not requiring the ventilators. By means of the decrease in the cloud condensation nuclei concentration to the order of 100 cm^?3 and less, it was succeeded for the first time to prevent the formation of clouds and fogs at adiabatic cooling of the humid air with equivalent speed of less than U _z = 28 cm/s. At U _z = 28–35 cm/s and nuclei concentration of 50–200 cm^?3, it becomes possible to simulate the fine-droplet hazes and fogs with monomodal spectra at average droplet diameter of 4–6 μm. At small and moderate rate U _z = 11–100 cm/s and active nuclei concentration of 300–700 cm^?3, one can simulate the convective clouds with wide polymodal spectra. The potential of modern models of cloud spectra formation and the prospects of application of the technique of ion-stimulated variations of condensation nuclei concentration are discussed.     

Properties of cloud and precipitation over the Tibetan Plateau

The characteristics of seasonal precipitation over the Tibetan Plateau(TP) were investigated using TRMM(Tropical Rainfall Measuring Mission) precipitation data(3B43). Sensitive regions of summer precipitation interannual variation anomalies were investigated using EOF(empirical orthogonal function) analysis. Furthermore, the profiles of cloud water content(CWC) and precipitable water in different regions and seasons were analyzed using TRMM-3A12 data observed by the TRMM Microwave Imager. Good agreement was found between hydrometeors and precipitation over the eastern and southeastern TP, where water vapor is adequate, while the water vapor amount is not significant over the western and northern TP.Further analysis showed meridional and zonal anomalies of CWC centers in the ascending branch of the Hadley and Walker Circulation, especially over the south and east of the TP. The interannual variation of hydrometeors over the past decade showed a decrease over the southeastern and northwestern TP, along with a corresponding increase over other regions.