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2.
浅谈暗筒式日照计日照时数失真的原因及解决方法   总被引：2，自引：0，他引：2  
总结多年地面测报工作实践经验,寻找日照时数失真的原因,并提出几点能有效避免日照时数记录失真的方法。  相似文献   

3.
Summary The seasonal and annual duration of sunshine in Austria during the 30 year period 1960–1989 is analyzed and the trends during this time interval are mapped. It is shown that sunshine decreased in the northern and eastern parts of Austria. In the mountain regions only small changes can be seen but there is some evidence that in the high mountain regions a remarkable increase in sunshine duration has taken place.Dedicated to O. Univ.-Prof. Dr. F. Steinhauser.With 7 Figures  相似文献   

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5.
Theoretical and Applied Climatology - In recent decades, automated sensors for sunshine duration (SD) measurements have been introduced in meteorological networks, thereby replacing traditional...  相似文献   

6.
Summary The total cloud cover is deduced from measurements of monthly mean averages of the percent of possible sunshine duration at three locations in Egypt, Cairo, Bahtim and Sedi-Barrani stations during the period 1987–1995. This sunshine-derived total cloud cover (Cs) is compared to conventional ground-based observations of total cloud covers (Cg) made by meteorological observers. A linear relationship between the two estimates is calculated, and the difference between the two estimates as a function of Cs and Cg is fitted with a least-squares linear equation. It is found that on the average the sunshine-derived values of total cloud cover are about 7% lower than the corresponding ground-based estimated of total cloud cover. Both of these parameters are mainly used in solar radiation models and the error sources are mainly depending upon the way to describe sky cover.  相似文献   

7.
选用广东南雄国家基准站1955—2000年日照资料,分析了南雄年、季日照时数的变化趋势、突变以及周期特征。结果表明:南雄年、季日照时数均随时间减少,年日照时数以-11.1 h/年的速度呈显著减少趋势发展;年代日照时数自20世纪60年代的最大值逐年代波动减小,到90年代达最小值;年、春及夏季日照时数在时间序列上存在明显的突变,其突变减少分别发生于1992、1978、1991年;年日照时数变化在32、12和5年时间尺度上存在周期振荡。  相似文献   

8.
1961-2009年东北地区日照时数变化特征   总被引：6，自引：0，他引：6       下载免费PDF全文
根据1961-2009年东北地区104个气象站的日照时数、气温、降水、风速和相对湿度资料,利用趋势分析、Mann-Kendall分析和相关分析等方法,研究东北地区日照时数月、季、年的时空变化特征,同时还对可能影响日照时数的气候因子进行分析。结果表明：东北地区5月日照时数最高,12月日照时数最低。年日照时数呈显著减少趋势,平均每10 a减少40.5 h;除秋季日照时数变化不显著外,其他季节日照时数均显著减少。在20世纪80年代初期存在明显的突变,日照时数开始减少。东北地区日照时数大致呈西高东低的经向分布;除黑龙江北部地区外,其余大部地区日照时数均呈减少的趋势,其中吉林北部地区减少最为明显。东北地区日照时数与气温呈负相关关系,相关系数为-0.40;与降水呈负相关关系,相关系数为-0.37;与风速呈正相关关系,相关系数为0.53;与相对湿度呈负相关关系,相关系数为-0.32。前三者均通过了99.9 %的信度检验,相对湿度通过了99.5 %的信度检验。  相似文献   

9.
以考虑地形遮蔽作用的实际起伏地形下可照时间分布式计算模型为基础,采用1：25万高分辨率数字高程模型（DEM）数据,计算了100m×100m分辨率的重庆市月可照时间以及年可照时间的空间分布,并分析了起伏地形下重庆市可照时间的逐月变化规律。结果表明：重庆市可照时间以6、7月份最高,2月份最低,全市年可照时间为2830h;地形因子对起伏地形下重庆市可照时间的影响程度具有随季节变化的特性;局地地形对可照时间的影响程度随季节而变,在冬半年,太阳高度角较低的季节,局地地形的影响较为显著。  相似文献   

10.
基于昌吉地区10个气象站点1970-2020年的气象观测数据,运用气候倾向法、5年滑动平均趋势分析法、M-K检验法、Pearson相关分析法以及ArcGIS10.7环境下的反距离加权(IDW)插值法探究昌吉地区日照时数时空变化规律及影响因素。结果表明:昌吉地区日照时数多年平均值为2840.3h,空间分布特征为“东部多,中西部少；山区多,平原少”,并呈现显著减少趋势,其速率为-62.8h/10a；从季度上看,日照时数夏季最高,其次是春季和秋季,冬季最低；下降速率冬季最快,其次是秋季和夏季,春季变化幅度最小；日照时数年内变化呈现双峰型,最大值出现在5月、7月和8月,最小值出现在12月,1-12月日照时数均呈现减少趋势,1月减少最为明显,12月次之。昌吉地区年日照时数在1987年发生突变；在影响因子方面,日照时数与总云量、水气压、雾日数呈现显著负相关,与大风日数、扬沙日数呈现显著正相关,说明,总云量、水气压、雾日数的逐年增加和大风日数逐年减少是日照时数逐年减少的主要原因。  相似文献   

11.
遵义市57713观测站近年日照时数减少原因浅析   总被引：2，自引：0，他引：2  
根据遵义市57713站1954--2007年的年总日照时数、年总降水量、年平均气温、年平均低云量等资料,对遵义市57713站日照时数进行了浅析。结果表明：近年来,遵义市57713站日照时数趋于减少,其原因与观测场周围环境改变、低云量增多有关。  相似文献   

12.
釆用气候倾向率和气候趋势系数对田阳县1961—2010年日照时数的年、季度资料进行分析,结果表明,田阳县近50a日照时数年、春季趋势减少明显,50a年日照时数气候倾向率为-35.532h/10a,春季气候倾向率为-14.944h/10a,夏、秋、冬季趋势减少不显著。  相似文献   

13.
Summary In this paper the daily and hourly values of sunshine duration, as well as the spells of virtually sunless days (daily sunshine duration 3.0 hrs) in Crete island are examined for the decade 1971–1980, which has been chosen for homogeneity of the existing observations.We have found that the sunshine duration at meteorological stations on the south side of Crete island exceeds the sunshine duration at the meteorological stations located on the north side of the island, which is attributed to the combination of Crete's relief and the prevalence of the north winds. We have also found that the sunshine duration measured at the meteorological stations on the east side of the island during the cold period of the year (October-March) exceeds the sunshine measured at the meteorological stations on the west side. This excess is attributed to the influence of the moving cyclones of the Mediterranean Sea especially during this season.We also believe that the moving cyclones are responsible for the same picture which appears when we study the virtually sunless spells with 1, 2 or three consecutive days at all the examined meteorological stations, while virtually sunless spells with more than 3 days show a concentration on meteorological stations on the north side of the island which is caused by the ground relief and the north-blowing winds.Finally, we found that virtually sunless spells follow a modified G. Polya distribution which, using theX 2-test, gives a very good fit at the 95% confidence level.
Zusammenfassung Es werden die tägliche und stündliche Sonnenscheindauer sowie Tage mit kurzer Besonnung (tägliche Sonnenscheindauer 3,0 Stunden) auf Kreta für die Dekade 1971–1980, die aufgrund der Homogenität der Beobachtungen ausgewählt wurde, untersucht.Die Sonnenscheindauer auf der Südseite der Insel übersteigt die auf der Nordseite, was auf das Relief Kretas und die vorherrschenden Nordwinde zurückgeführt wird. In der kalten Jahreszeit (Oktober bis März) übersteigt die Sonnenscheindauer im Osten die im Westen. Dieser Unterschied dürfte auf den zu dieser Zeit starken Einfluß der wandernden Zyklonen im Mittelmeer zurückzuführen sein.Es wird vermutet, daß das vermehrte Auftreten von ein bis drei aufeinanderfolgenden, praktisch sonnenfreien Tagen im Westen auf die gleiche Ursache zurückzuführen ist, während mehr als drei sonnenfreie Tage konzentriert im Norden auftreten, wohl wegen des Reliefs und des Nordwinds.Schließlich wird gezeigt, daß die praktisch sonnenfreien Tage einer modifzierten Polya-Verteilung folgen. EinX 2-Test ergibt eine gute Übereinstimmung mit einem 95% Konfidenzintervall.

With 3 Figures  相似文献   

14.
Summary Radiometric ground truth data from seven Norwegian stations (58–64° N), and from five other European stations (38–61° N), are compared to satellite-derived data in the present paper. Hourly global irradiance at ground level is estimated by the Heliosat procedure from the “visible” channel of the geostationary satellite METEOSAT. With increasing latitude this satelllite sees the earth’s surface at an increasingly unfavourable angle. Nevertheless, in this paper, global irradiance estimates reproduce high latitude ground truth data with negligible Mean Bias Deviations (MBD) and only minor deviations regarding frequency distributions. Moreover, the Root Mean Square Deviations (RMSD) are comparable to those typically seen between ground truth stations some 20–30 km apart. Using a number of auxiliary models, a multiplicity of ground level solar radiation data is obtained from satellite-derived global irradiance data, and made available at the SATEL-LIGHT www server. The accuracy of the half-hourly data thus derived from Heliosat global irradiances, using models for diffuse fraction, luminous efficacy and slope/horizontal ratios, is successfully verified against ground truth data. Received August 31, 2000/Revised January 31, 2001  相似文献   

15.
陈传振  张秀娟  李莉  董明 《山东气象》2021,41(4):95-101
利用南极长城站 1988—2017 年连续的日照、云量、天气现象、气温和湿度等观测资料,研究 了南极西部乔治王岛 30 a的日照变化特征及其与气象要素的关系。 结果显示,南极地区的日照时 间远少于中低纬度地区,这主要因为该地区常年以阴云天气为主,云层对太阳光的遮挡降低了日 照时间的总量值。2000 年以来,随着总云量和相对湿度的增加,日照时间呈减少趋势。 根据统计分析月平均相对湿度以及每月出现雨、雪、雾、轻雾、吹雪等天气现象和最低气温三0 ℃的天数,发 现液态（ 固态） 现象的发生频率与日照百分率的变化趋势一致（相反） ,即日照百分率低（高） 时,液态现象少（多） ,固态现象多（少） 。  相似文献   

16.
利用甘肃省26个气象站1961—2010年逐月日照时数资料,采用线性趋势分析、异常年份分析、Mann-Kendall和功率谱等方法,分析了日照时数的时空变化及突变特征.结果表明:50年来,甘肃年日照时数表现为缓慢的下降趋势,气候倾向率为-0.29 h·(10 a)-1,1997年以来显著减少;夏、冬季日照时数呈下降趋势,春、秋季则呈增加趋势;年日照时数异常偏少年份主要出现在20世纪80年代,而异常偏多的年份多发生在20世纪90年代至今;甘肃年日照时数空间差异明显,分布趋势基本上呈由东南向西北逐渐增多形势.Mann-Kendall和Yamamoto突变检验表明,四季日照时数未发生显著突变.周期分析表明,甘肃年日照时数存在2 a的振荡周期,通过了90%置信度检验.  相似文献   

17.
Summary A.Ångström has assumed a linear relation between daily totals of the global radiation measured at a certain place and the corresponding daily values of the relative duration of sunshine. Other authors have applied the same relationhip, however, with a different unit of time, such as a 5-day period, a 10-day period and a month. In this paper a period of one hour is chosen as unit.Ångström's Q 0 – and -values have been determined for De Bilt and for the one-hour periods L. A. T. of the mean day in each of the 60 months of the 5-year period 1954–1958. For the mean day of each of the 12 months of the year the arithmetic means of the 5Q 0 – and 5 -values for the same hours have been calculated.A simple method to compute daily amounts of global radiation by means of these averageQ 0 – and -values has been applied to De Bilt and Wageningen for all days of 1958. The square root of the residual variance of the thus determined daily amounts appeared to amount to 0.75 for De Bilt and to 0.82 for Wageningen compared with that computed for Wageningen fromÅngström's formula for daily amounts directly. This result shows that the average hourlyQ 0 – and -values for De Bilt may be used to calculate daily amounts of global radiation for any place in the Netherlands.
Zusammenfassung A.Ångström hat eine lineare Beziehung zwischen den Tagessummen der Globalstrahlung an einem Ort und den entsprechenden täglichen Werten der relativen Sonnenscheindauer angenommen. Andere Autoren haben dieselbe Beziehung benützt, jedoch mit verschiedenen Zeiteinheiten, wie einer Pentade, einer Dekade oder einem Monat. In der vorleigenden Untersuchung ist die Dauer einer Stunde als Einheit gewählt worden. DieÅngströmschenQ 0 – und -Werte sind bestimmt worden für alle Stunden in wahrer Sonnenzeit für den mittleren Tag jedes der 60 Monate der fünfjährigen Periode 1954–1958 für De Bilt. Daraus sind die arithmetischen Mittel der 5Q 0 – und der 5 -Werte für dieselben Stunden des mitteleren Tages in jedem der 12 Monate des Jahres berechnet worden.Eine einfache Methode zur Berechnung der Tagessummen der Globalstrahlung mit Hilfe der mittlerenQ 0 – und -Werte wurde für De Bilt und Wageningen auf alle Tage des Jahres 1958 angewandt; dabei hat die Quadratwurzel der Restvarianz der also berechneten Tagessummen für De Bilt 0,75 mal und für Wageningen 0,82 mal den Wert der Quadratwurzel der Restvarianz der in direkter Weise mit Hilfe derÅngströmschen Formel für Wageningen berechneten Tagessummen ergeben. Daraus geht hervor, daß für jeden Ort in den Niederlanden die Tagessumme der Globalstrahlung nach der oben beschriebenen Methode mit genügender Genauigkeit berechnet werden kann.
Résumé A.Ångström a supposé une relation linéaire entre les sommes journalières du rayonnement global observées en un lieu donné et les valuers journalières correspondantes de la durée d'insolation relative. D'autres auteurs ont admis la même relation, mais en employant des unités de temps différentes, telles que la pentade, la décade ou le mois. C'est la période d'une heure qui a été choisie ici comme unité. Les valeursQ 0 et d'Ångström ont été déterminées pour De Bilt pour chaque heure, en temps solaire vrai, au cours d'un jour moyen de chaque mois de la période 1954–1958. Les moyennes arithmétiques de cinq valuersQ 0 et ont été calculées pour les mêmes heures du jour moyen de chacun des douze mois de l'année.Une méthode simple de calcul des sommes journalières du rayonnement global à l'aide de ces valeurs moyennes deQ 0 et de a été appliquée pour De Bilt et Wageningen pour tous les jours de l'année 1958. On a trouvé que le rapport de la racine carrée de la variance résiduelle des valuers journalières calculées de cette façon à celle des valeurs journalières calculées directement au moyen de la formule d'Ångström pour Wageningen se montait à 0,75 pour De Bilt et à 0,82 pour Wageningen. Ce résultat prouve que l'on peut appliquer les valeurs horairesQ 0 et calculées pour De Bilt au calcul des sommes journalières du rayonnement global en chaque point des Pays-Bas.

The present investigation is treated more in detail in a Scientific Report of the Royal Netherlands Meteorological Institute No. WR-60-6.  相似文献   

18.
Summary ¶Global, diffuse, and horizontal direct (beam) irradiances have been evaluated for 13 stations in Germany where the time series vary between 11 and 48 years. Global irradiance has decreased significantly at two stations and increased at four stations. The mean trend in global is an increase of 1.94Wm–2 or 1.83% per decade. Diffuse irradiance has decreased at five stations, with a mean reduction of 2.44Wm–2 or 3.46% per decade, while horizontal direct irradiance has increased an average of 4.86Wm–2 or 10.40% per decade at five stations. Increases in global and direct are most common at stations in the southwest region of Germany, decreases in global were observed in the southeast, and there was an absence of spatial homogeneity in the diffuse trends. Spatial variability in irradiance over Germany is higher in the direct component compared to variability in global and diffuse.Trend analyses of concomitant time series of radiation, bright sunshine duration, and modeled estimates of Ångströms turbidity coefficient suggest that long-term decreases in aerosols are the most likely cause of increases in global irradiance observed at Mannheim, Norderney, and Trier; decreases in diffuse at Hohenpeissenberg, Kassel, Mannheim, and Trier; and increases in direct irradiance at Bocholt, Kassel, Mannheim, and Trier. An increase in sunshine duration at Freiburg likely contributed to an increase in global and direct irradiance observed at that station.  相似文献   

19.
Two new Boolean parameters are defined: the sunshine number (related to the state of the sky) and the sunshine stability number (which is as a measure of the fluctuation of the radiative regime). Elementary statistical and sequential properties of both parameters are presented in this paper. Actinometric and meteorological data measured at 15?s lag during 2009 in Timisoara (Romania, southeastern Europe) are used. The yearly series of daily averaged sunshine number has negative skewness and kurtosis. The series of daily averaged sunshine stability number has positive skewness and kurtosis. The series of daily averaged values of sunshine number are best described by an ARIMA(0,1,2) model. ARIMA(0,1,0) and ARIMA(0,2,0) models (associated with an appropriately defined white noise) may be used for synthesis of the sunshine number time series. The first model is to be preferred for practical reasons. The series of daily averaged values of sunshine stability number are best described by an ARIMA(2,2,1) model. The ARIMA(0,0,0) model is recommended to be used for generating time series of sunshine stability number. This model may be used for any particular day during the year and the only parameter depending on the day is the white noise standard deviation. A relationship between the white noise standard deviation and the daily averaged sunshine stability number is proposed.  相似文献   

20.
Sunshine duration data are desirable for calculating daily solar radiation (R s) and subsequent reference evapotranspiration (ET0) using the Penman–Monteith (PM) method. In the absence of measured R s data, the Ångström equation has been recommended by the Food and Agriculture Organization (FAO) of the United Nations. This equation requires actual sunshine duration that is not commonly observed at many weather stations. This paper examines the potential for the use of artificial neural networks (ANNs) to estimate sunshine duration based on air temperature and humidity data under arid environment. This is important because these data are commonly available parameters. The impact of the estimated sunshine duration on estimation of R s and ET0 was also conducted. The four weather stations selected for this study are located in Sistan and Baluchestan Province (southeast of Iran). The study demonstrated that modelling of sunshine duration through the use of ANN technique made acceptable estimates. Models were compared using the determination coefficient (R 2), the root mean square error (RMSE) and the mean bias error (MBE). Average R 2, RMSE and MBE for the comparison between measured and estimated sunshine duration were calculated resulting 0.81, 6.3 % and 0.1 %, respectively. Our analyses also demonstrate that the difference between the measured and estimated sunshine duration has less effect on the estimated R s and ET0 by using Ångström and FAO-PM equations, respectively.  相似文献   

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