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1.
Comments are presented on a paper ofG. F. Schilling andJ. Carson on the continuous recording of the conductivity of air in closed rooms by means of the vibrating reed electrometer and a Brown recorder. Similar observations have been made in 1953 by the author at Mt. St. Vincent near New York. The sudden increases (up to four times the normal value) of the conductivity were also noticed, occasionally, and it is shown that they cannot be explained by assuming a sudden appearance of nuclei; this would have to be of the order of 700 000 nuclei per cm3 which is about 10 times the number observed in cities. It is believed that malfunctioning of the vibrating reed electrometer is the reason for these spikes in the record.
Zusammenfassung Die kontinuierliche Registrierung der elektrischen Leitfähigkeit der Luft mittels des Vibrating Reed-Elektrometers durchG. F. Schilling undJ. Carson zeigte gelegentlich plötzliches Anwachsen der Leitfähigkeit auf das Vierfache des normalen Wertes, was von den Verfassern als das Eindringen sehr hoher Zahlen von schweren Ionen (geladenen Kondensationskernen) interpretiert wurde. Verfasser hat in Mt. St. Vincent (in der Umgebung von New York) im Sommer 1953 ähnliche plötzliche Schwankungen registriert, wobei ein Registrierapparat derselben Type verwendet wurde. Verfasser zeigt, daß man das plötzliche Eindringen kernreicher Luft mit Kernzahlen bis zu 700 000 per cm3 annehmen müßte, um das Anwachsen der Leitfähigkeit auf das Vierfache des normalen Wertes zu erklären. Da diese Zahlen ungefähr zehnmal größer sind, als man gewöhnlich in Stadtluft beobachtet, muß vermutet werden, daß das Vibrating Reed-Elektrometer selbst gelegentlich schlecht funktioniert und daß daher solche Werte nicht berücksichtigt werden sollten.

Résumé Les enregistrements continus en chambre close de la conductibilité électrique de l'air au moyen de l'électromètre «vibrating reed» effectués parG. F. Schilling etJ. Carson montrent que celle-ci augmente parfois jusqu'au quadruple de la valeur normale. Ce phénomène fut expliqué par les auteurs comme résultant de l'apparition soudaine d'un três grand nombre de gros ions (noyaux de condensation chargés). Pendant l'été de 1953, à Mt. St. Vincent (dans les environs de New York), l'auteur a enregistré avec un électromètre du même type des variations soudaines semblables. Pour expliquer l'augmentation de la conductibilité jusqu'au quadruple de la valeur normale, il faudrait admettre l'irruption de masses d'air contenant jusqu'à 700 000 noyaux par cm3. Vu que ce nombre est à peu près dix fois plus grand que celui que l'on observe généralement dans l'atmosphère d'une ville, on est obligé de supposer que parfois l'électromètre «vibrating reed» lui-même fonctionne mal et que de telles valeurs ne devraient pas être retenues.
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2.
Summary The annual and diurnal variation of the conductivity near the ground at Athens, based on long-term data, are presented. The diurnal double oscillation is a characteristic of the atmospheric electric climate of Athens. In addition, the influence of air pollution due to smoke and sulfur dioxide and of wind speed (as an element affecting the dispersion of pollulants) on large ion concentration and on conductivity has been examined. The air pollution, which is often severe in Athens area, results in decreasing conductivity and increasing large ion concentration, while the influence of wind speed is also pronounced. The results justify the use of conductivity as a pollution index. Finally the plausible influence of air temperature and relative humidity and of their rate of change on air electrical conductivity, has been examined. The results are ambiguous and depending on the season, especially for relative humidity.With 3 Figures  相似文献   

3.
4.
Summary The electrical conductivity of the atmosphere at any part of the earth's surface depends on the local concentration of small ions. This in turn depends 1. on their rate of production and 2. on their rate of removal. The removal is due principally to attachment to condensation nuclei. Methods are described for counting the nuclei and for determining their sizes and masses. The ratios of charged to uncharged nuclei, when they are in equilibrium with the small ions, are determined for nuclei of various sizes. Observations on nuclei in the free atmosphere show that they are usually not in equilibrium. The difficulty of establishing any simple relation between atmospheric conductivity, rate of ion-production and nucleus concentration is increased by the discovery that the air-borne radioactive matter which contributes to the small-ion production tends to increase with increase of nucleus concentration.
Zusammenfassung Die elektrische Leitfähigkeit der Atmosphäre an einer beliebigen Stelle der Erdoberfläche hängt von der örtlichen Konzentration kleiner Ionen ab; diese ist ihrerseits bedingt 1. durch die Ionisierungsstärke und 2. durch die Geschwindigkeit ihrer Vernichtung. Die Vernichtung von Kleinionen ist vor allem auf die Anlagerung an Kondensationskerne zurückzuführen. Es werden Methoden für die Kernzählung und für die Bestimmung von Größe und Maße der Kerne beschrieben. Das Verhältnis von geladenen zu ungeladenen Kernen wird für den Fall, daß sie im Gleichgewicht mit den kleinen Ionen sind, für Kerne verschiedener Größe bestimmt. Kernbeobachtungen in der freien Atmosphäre ergeben, daß dieses Gleichgewicht gewöhnlich nicht besteht. Die Aufstellung einer einfachen Beziehung zwischen der atmosphärischen Leitfähigkeit, dem Prozentsatz der Ionenbildung und der Kernkonzentration wird noch erschwert durch die Feststellung, daß die aus der Luft stammenden radioaktiven Substanzen, die zur Bildung von Kleinionen beitragen, mit einer Zunahme der Kernkonzentration ihrerseits ebenfalls eine Zunahme zeigen.

Résumé La conductibilité électrique de l'atmosphère en un endroit quelconque de la terre dépend de la concentration locale des petits ions; celle-ci est à son tour commandée 1. par l'intensité de l'ionisation et 2. par la vitesse de leur disparition. La destruction des petits ions est due surtout à leur dépôt sur des noyaux de condensation. On expose des méthodes de dénombrement des noyaux et de détermination de leur grosseur et de leur masse. On établit le rapport des noyaux chargés aux noyaux non chargés dans le cas où ils sont en équilibre avec les petits ions, et cela pour des noyaux de différentes grosseurs. Des observations de noyaux de l'atmosphère libre prouvent que cet équilibre n'est généralement pas réalisé. Dans la recherche d'une relation simple entre la conductibilité atmosphérique, le taux de formation d'ions et la concentration en noyaux, on se heurte à la difficulté suivante: les substances radioactives provenant de l'air et qui contribuent à la formation de petits ions augmentent en même temps que la concentration des noyaux.


Dedicated to Professor Dr.H. Benndorf on the occasion of his eightieth birthday.  相似文献   

5.
Aircraft observations of electrical conductivity and cloud microphsical, dynamical and other electrical parameters were made in warm stratocumulus and cumulus clouds forming during the summer monsoon seasons (June-September) of 1983 and 1985 in the Deccan Plateau region, India. A Gerdien type cylindrical condenser was used for the measurement of electrical conductivity. The variations in the electrical conductivity are observed to be closely associated with the updrafts and downdrafts in the cloud, liquid water content, cloud droplet charge and coro-na discharge current. The value of electrical conductivity in warm clouds is found to be in the order of 10-12 ohm-1 m-1 which is two orders higher than that observed in clear-air at cloud-base levels in some regions by other investigators.Classical static electricity concepts predict reduced conductivity values inside clouds. Cloud electrical conductivi-ty measurements, particularly in warm clouds are few and the results are contradictory. The recently identified mech-anism of vertical mixing in clouds lends support to coovective charge separation mechanism with inherent larger than clear-air values for cloud electrical conductivity and therefore consistent with the measurements reported herein.  相似文献   

6.
A new dimensionless parameter is proposed enabling to estimate the aridity of physiographic territories for any spatial and temporal scales. The potential of the use of this parameter is demonstrated by the example of the territory of Uzbekistan.  相似文献   

7.
Simultaneous measurements of the activity concentrations of radon and its progeny, and conductivity of both polarities i.e., positive and negative conductivities, were made at a height of 1 m above the ground at Mysore (12°N, 76°E, 767 m above mean sea level), India. Diurnal and seasonal variations of activities of radon and its progeny show their peak values in the early morning hours throughout the year. Observations show an increase in the concentration of radon and its progeny during nighttime compared to the daytime values, and are higher in winter than in other seasons. The electrical conductivity of the atmosphere that depends on the ionization rate also exhibits similar trends. These results are discussed in terms of ionization rate due to radioactivity and the influence of meteorological parameters on radioactivity. The results also show that the concentrations of radon, its progeny, and the electrical conductivity of both polarities exhibit a positive correlation with the relative humidity and are negatively correlated with the temperature of the atmosphere.  相似文献   

8.
分析了气温,气压变化造成的高度表误差及气温及气温的变化带来的飞 机空速表误差,认为现行民航航线飞行安全高度的规定存在一定的不足,并提出了改进办法。  相似文献   

9.
The sensitivity of land surface energy partitioning to near-surface air temperature (T a) is a critical issue to understand the interaction between land surface and climatic system. Thus, studies with in situ observed data compiled from various climates and ecosystems are required. The relations derived from such empirical analyses are useful for developing accurate estimation methods of energy partitioning. In this study, the effect of T a on land surface energy partitioning is evaluated by using flux measurement data compiled from a global network of eddy covariance tower sites (FLUXNET). According to the analysis of 25 FLUXNET sites (60 site-years) data, the Bowen ratio is found to have a linear relation with the bulk surface resistance normalized by aerodynamic and climatological resistance parameters in general, of which the slope and intercept are dependent on T a. Energy partitioning in warmer atmosphere is less sensitive to changes in land surface conditions. In addition, a negative relation is found between Bowen ratio and T a, and this relation is stronger above less vegetated surface and under low vapor pressure deficit and low received radiative energy condition. The empirical results obtained in this study are expected to be useful in gaining better understanding of alternating surface energy partitioning under increasing T a.  相似文献   

10.
中国地面气温变化趋势中的城市化影响偏差   总被引:18,自引:0,他引:18  
在中国大陆2300个气象台站网中遴选出138个参考站,对614个国家级气象站和138个参考站1961 2004年的月平均气温资料进行了非均一性检验和订正,利用REOF(旋转主分量)分析方法,按照气温变率空间相关特点将中国大陆划分为6大区域,并采用经纬度网格面积加权平均法分别建立了中国大陆及其6大区域平均的国家站和参考站的月、季、年地面气温时间序列,对国家站和参考站序列进行了对比分析。结果表明,由国家站资料建立的中国大陆年平均气温序列在44年间线性增温率为0.278 C/10 a,而由参考站资料建立的中国大陆年平均气温序列同期增温率为0.202℃/10 a。就中国大陆平均来说,1961 2004年国家级站城市化增温率为0.076 C/10 a,占全部增温率的27.33%。在6大区域中,除北疆区外,其他地区年平均城市化增温率均非常显著。其中城市化影响最大的地区是江淮区,年平均热岛增温率为0.086℃/10 a,其后依次为东北华北区、青藏高原区、华南区和西北区,年平均热岛增温率分别达到0.060、0.059、0.042和0.042℃/10 a。各区域年平均热岛增温贡献率由大到小排列依次为江淮区55.48%、青藏高原区23.23%、华南区23.20%、东北华北区15.35%、西北区13.73%、北疆区-1.57%。因此,中国大陆20世纪60年代初以来城市化造成的国家站地面气温增暖偏差非常显著,今后应予以订正,以便建立代表背景气候变化的区域平均气温序列。  相似文献   

11.
12.
本文仔细考察了华北—山地采样点获得的大气气溶胶元素浓度随气象条件的变化规律和各元素浓度之间的相互关系;发现,气溶胶中由人为污染物形成的那些颗粒物元素的浓度(特别是硫)相当高,其数值与在高度工业化的美国东北部和西欧的工业城市的观测结果相当;颗粒物流的浓度的变化与局地天气条件的变化之间相关性很差,整个观测期间硫的浓度波动也不大,这与地壳灰尘元素的变化规律完全不同。这表明,气溶胶硫污染已经成为较大范围的区域性问题,城市污染可能已影响到广大农村和山区。  相似文献   

13.
14.
为探讨不同气温指标对城市夏季供电量的影响,对2002--2004年6—9月天津市区逐日供电量、日最大负荷、日最小负荷与02、08、14时和20时,日平均、日最高和日最低气温共7种气温指标的相关性进行综合统计分析,并对相关系数作假设检验。结果表明:平均气温与夏季逐日供电量、日最大负荷相关性最好,02时气温与最小负荷的相关性最高。日平均气温和02时气温是影响城市夏季供电量的主要气象要素。  相似文献   

15.
为探讨不同气温指标对城市夏季供电量的影响,对天津市区2002—2004年6—9月逐日供电量、日最大负荷、日最小负荷与02、08、14时和20时、日平均、日最高和日最低气温共7种气温指标的相关性进行综合统计分析,并对相关系数作假设检验。结果表明:平均气温与夏季逐日供电量、日最大负荷相关性最好,02时气温与最小负荷的相关性最高。日平均气温和02时气温是影响城市夏季供电量的主要气象要素。  相似文献   

16.
The Tibet Plateau (TP) is a key region that imposes profound impacts on the atmospheric water cycle and energy budget of Asia, even the global climate. In this work, we develop a climatology of origin (destination) of air mass and moisture transported to (from) the TP using a Lagrangian moisture diagnosis combined with the forward and backward atmospheric tracking schemes. The climatology is derived from 6-h particle positions based on 5-year (2005?C2009) seasonal summer trajectory dataset from the Lagrangian particle dispersion model FLEXPART using NCEP/GFS data as input, where the regional model atmosphere was globally filled with particles. The results show that (1) the dominant origin of the moisture supplied to the TP is a narrow tropical?Csubtropical band in the extended Arabian Sea covering a long distance from the Indian subcontinent to the Southern Hemisphere. Two additional moisture sources are located in the northwestern part of TP and the Bay of Bengal and play a secondary role. This result indicates that the moisture transporting to the TP more depends on the Indian summer monsoon controlled by large-scale circulation. (2) The moisture departing from the TP can be transported rapidly to East Asia, including East China, Korea, Japan, and even East Pacific. The qualitative similarity between the regions of diagnosed moisture loss and the pattern of the observed precipitation highlights the robustness of the role of the TP on precipitation over East Asia. (3) In contrast to the moisture origin confined in the low level, the origin and fate of whole column air mass over the TP is largely controlled by a strong high-level Asian anticyclone. The results show that the TP is a crossroad of air mass where air enters mainly from the northwest and northeast and continues in two separate streams: one goes southwestwards over the Indian Ocean and the other southeastwards through western North Pacific. Both of them partly enter the trade wind zone, which manifests the influence of the air mass transport over the TP on the budget of global atmosphere compositions.  相似文献   

17.
基于TIGGE资料的东亚地面气温预报的不一致性研究   总被引:1,自引:0,他引:1       下载免费PDF全文
基于TIGGE资料中欧洲中期天气预报中心(ECMWF)、美国国家环境预报中心(NCEP)和中国气象局(CMA)3个集合预报系统的地面气温集合预报资料,运用跳跃指数研究了3个集合预报系统中东亚地面气温的控制预报及集合平均预报的不一致性。结果表明,各个集合预报系统地面气温预报的时间平均不一致性指数差异较大。ECM WF时间不一致性指数最小,NCEP次之,CM A最大。另外NCEP的控制预报、ECM WF的控制预报和集合平均预报,这三者的时间平均不一致性指数随预报时效延长而增加,且集合平均预报一致性优于控制预报。而对于CMA预报的不一致性,无论是控制预报还是集合平均预报总体上都稳定地保持在较高的水平。此外,ECMWF的地面气温冬(夏)季预报的不一致性相对较强(弱),且单点跳跃随预报时效延长变化不明显,而控制预报和集合平均预报的异号两点跳跃以及三点跳跃出现的频率总体上随预报时效延长略有增加。  相似文献   

18.
Summary The stationary vertical distribution of a weightless radioactive substance is considered supposing a horizontal homogeneity. A two-layer exponent law of the height is accepted for the vertical turbulent diffusion coefficient. The obtained solution is applied to the surface layer using the results ofMonin andObukhov about its structure.
Zusammenfassung Es wird die stationäre vertikale Verteilung gewichtloser radioaktiver Substanzen unter der Annahme einer horizontalen Homogenität untersucht. Für die Änderung des vertikalen Austauschkoeffizienten mit der Höhe wird ein Zweischichten-Potenzgesetz angenommen. Die erhaltene Lösung wird auf die bodennahe Luftschicht angewendet, für die eine Struktur nachMonin undObukhov zugrunde gelegt ist.

Résumé On examine la répartition verticale stationnaire de substances radioactives sans poids en admettant une homogénéïté horizontale. On admet une loi potentielle en deux couches pour la modification avec l'altitude du coefficient vertical d'échange. La solution obtenue est appliquée à la couche voisine du sol pour laquelle on utilise une structure selonMonin etObukhov.
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19.
Abstract

The accumulation of condensed water in moist rising air is discussed in relation to the ratio of the air speed co the fall speed of precipitation. The maximum ultimate accumulation occurs when that ratio is near unity; the duration of a transient phase is proportional to the inverse of the fall speed of precipitation when updraft are weak, and to the inverse of air speed when the air speed is moderate or strong. The kinematic framework presented has dynamical implications that help explain some behaviour of showers and storms.  相似文献   

20.
From the COADS (Comprehensive Ocean-Atmosphere Data Set) I and the COADS II, we got a monthly data set of sea surface temperature (SST). zonal and meridional wind components at sea level (U,V) and sea level pressure (SLP) with 4o × 4o grid system covering the period from Jan. 1950 to Dec. 1987 to study the evolutional features of the quasi-biennial oscillation (QBO) in the air-sea system. The analytic method of complex empirical orthogonal function (CEOF) is used to obtain the composite temporal sequences of amplitude (six phases for half a period) for the first and the second main components of SST, U, V and SLP. It is shown from the results that the main character-istics for different phases of the sea surface temperature anomaly’s (SSTA) QBO are warm water / cold water in the equator of the eastern Pacific (EEP). There are two warm or cold water centers of the SSTA in the EEP, which are lo-cated in the equator of the central Pacific (ECP) and the east part of the EEP. The features of the source propagation and the influence of these two centers on atmospheric circulation are discussed and it can be seen that in the forma-tion of these two centers, there are different features in oceanic and atmospheric circulations and air-sea coupled pro-cess.  相似文献   

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