几种水平面太阳总辐射量计算模型的对比分析

利用中国区域1961-1999年39 a间98个常规气象观测数据,建立6个模型分别以天文辐射、干洁大气总辐射和湿洁大气总辐射为起始数据,进行太阳辐射日总量的模拟,对比分析了6个水平面太阳总辐射量计算模型的性能.结果表明:在三种起始数据中,干洁大气总辐射和湿洁大气总辐射均能较好地体现宏观地势对太阳辐射空间分布的影响,以湿洁大气总辐射为起始数据的计算模型拟合精度相对较高.对6个水平面太阳总辐射量计算模型的对比分析发现:2个以日照百分率为主导因子,气温日较差为修正项的综合模型拟合误差最小,精度最高;经典的日照百分率模型次之,但其模型系数最稳定可靠;3个气温日较差模型拟合效果最差.最终选用经验系数稳定、拟合精度较高的日照百分率模型,制作了2001年中国水平面太阳辐射日总量空间分布图.     

Luminous efficacy of global solar radiation on a horizontal surface for overcast and intermediate skies

Summary  In the first part of this research two models for the luminous efficacy of global solar radiation on horizontal surfaces and overcast skies have been developed. The first of these models is developed using a method similar to that proposed by Littlefair (1988). The second model has been obtained from the corresponding illuminance and irradiance models in an, apparently, new approach to the subject. In the second part of this research, a model for the luminous efficacy of global solar radiation for intermediate skies and horizontal surfaces is developed from the corresponding illuminance and irradiance models. The model for intermediate skies is given by the same mathematical function as that of the analogous model for overcast skies, and only the empirical constants change. In all the cases the only independent variables used are the solar altitude and the brightness index. The models proposed in the present paper have been statistically tested, and their prediction accuracy compared with other models available in the scientific literature. Received June 26, 2000 Revised December 9, 2000     

Actinic flux and global radiation

Summary The observed relationship between global radiation and actinic flux in a radiation experiment above grassland corresponds well with the theoretical relationship expressed by Madronich.As a direct consequence of this relationship the photosynthetic light compensation point, determined in the field with an actinic flux sensor, must occur earlier in the morning and later in the evening than when determined with a global radiation sensor. For plants, an actinic flux day is longer than a global radiation day.With 1 Figure     

Evaluation and estimation of daily global solar radiation from the estimated direct and diffuse solar radiation

Active layer plays a key role in regulating the dynamics of hydrothermal processes and ecosystems that are sensitive to the changing climate in permafrost regions. However, little is known about the hydrothermal dynamics during freeze-thaw processes in permafrost regions with different vegetation types on the Qinghai-Tibetan Plateau (QTP). In the present study, the freezing and thawing processes at four sites (QT01, 03, 04, and 05) with different vegetation types on the QTP was analyzed. The results indicated that the impact on the soil water and heat during the summer thawing process was markedly greater than that during the autumn freezing process. Furthermore, the thermal-orbit regression slopes for all sites exhibited a homologous variation as the depth increased, with the slowest attenuation for the meadow sites (QT01 and QT03) and a slightly faster attenuation for the desert steppe site (QT05). The air and ground surface temperatures were similar in winter, but the ground surface temperature was significantly higher than the air temperature in summer in the radiation-rich environment at all sites on the QTP. The results also indicated that the n-factors were between 0.36 and 0.55 during the thawing season, and the annual mean temperature near the permafrost table was between − 1.26 and − 1.84 °C. In the alpine desert steppe region, the thermal conditions exhibited to show a warming trend, with a current permafrost table temperature of − 0.22 °C. The annual changing amplitude of the ground temperature at the permafrost table was different for different vegetation types.     

太阳辐射各因子的变化对太阳紫外辐射的影响

利用北京地区１９９０年太阳分光辐射的观测资料，计算了影响太阳紫外辐射的各因子的变化所引起的太阳紫外辐射的变化。当臭氧、水汽、气溶胶分别减少５％时，到达地面的太阳紫外辐射将分别增加０．８４％、０．２７％和１．９０％。在分析太阳紫外辐射的变化趋势时，应当全面考虑各个因子的影响。     

和静县太阳总辐射计算及太阳能资源评估

基于焉耆国家基准气候站1993-2012年逐月太阳总辐射和日照观测资料以及和静、巴音布鲁克1961-2012年月日照百分率资料,建立回归分析方程,推算和静县山区及平原地区逐月的太阳总辐射,对比分析了和静县山区及平原地区太阳总辐射变化特征,从太阳能资源丰富度、资源稳定性及可利用价值等方面对和静县太阳能资源状况进行评估。结果表明：1961-2012年和静县平原及山区太阳总辐射均呈减少的趋势,平原地区7月太阳总辐射最多,山区5月最多,最少值均出现在1月;平原地区属太阳能资源很丰富区,山区为丰富区;平原地区及山区太阳能资源均较稳定;平原地区年平均可利用太阳辐射的天数为286 d,山区为267 d;平原和山区一天中上午和中午是最有利的利用时段。     

The regression of net radiation upon solar radiation

Theoretical and Applied Climatology - A number of studies have sought to relate net radiation over natural surfaces to incoming global radiation. Several deficiencies are noted in interpretation of...     

Estimating global solar radiation

A model is presented to calculate daily totals of global solar radiation. First, cloudless sky radiation is evaluated from transmission due to absorption and scattering. Cloud effects are added using cloud layer transmission. A simple expression to account for additional radiation due to reflection between the ground surface and cloud bases is also included. Atmospheric transmissions are obtained from previous studies. Precipitable water and observations of cloud type and amount for different layers in the atmosphere are the only meteorological variables required. The model is evaluated and tested with data collected at stations in and around Lake Ontario: a lake station near Grimsby in 1969 and land stations at Burlington, Scarborough, Peterborough, Trenton and Kingston, Ontario in 1972 and 1973 during the International Field Year for the Great Lakes. Good agreement between calculated and measured radiation was obtained at all stations, particularly for 5- and 10-day means. Model performance was largely independent of both cloud amount and season.     

Transient processes of solar radiation

In the present study, transients—rises and falls of the value of solar irradiance in the conditions of alternating Cumulus humilis and Cumulus fractus clouds—are studied to find their main characteristics, that is, the scope of their duration, magnitude, frequency, and shape. Of course, all these variables have a stochastic character and have been calculated using statistical analysis of ten automatic recordings. The results of the study characterize these clouds and show the degree of problems in generating PV electricity.     

Studies of solar radiation and albedo in the antarctic

Summary The preliminary report deals with studies of the direct solar radiation and albedo which were performed during the US-IGY-Antarctic Expedition 1957/58. The intensity of the direct solar radiation at Little America V (78° S, 162° W, 44 meters above sea level) corresponds to the intensities measured in the European Alps at 3000 meters in June. The intensity at the South Pole (2800 meters above sea level) agrees with the intensity in the European Alps at 3000 meters in December. Measurements of the albedo at the South Pole and at Byrd Station (80° S, 120° W, 1515 meters above sea level) gave mean value of 89 percent, the whole range being 84 to 93 percent.

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Zusammenfassung Die vorläufige Mitteilung gibt einige Ergebnisse von Messungen der direkten Sonnenstrahlung und der Albedo, die während der US-IGJ-Antarktis-Expedition 1957/58 ausgeführt wurden. Die Intensitätdet der direkten Sonnenstrahlung in Little America V (78° S, 162° W, 44 m über dem Meeresniveau) entspricht den Intensitäten in den europäischen Alpen in 3000 m Höhe im Juni. Die Intensität am Südpol (2800 m über dem Meeresniveau) stimmt mit den Intensitäten in den europäischen Alpen in 3000 m Höhe im Dezember überein. Messungen der Albedo am Südpol und an der Byrd-Station (80° S, 120° W, 1515 m über dem Meeresniveau) ergaben einen Mittelwert von 89%, die Einzelwerte schwankten zwischen 84 und 93%.

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Résumé Note préliminaire concernant les mesures de rayonnement solaire et d'albédo faites lors de l'expédition américaine de l'Année géophysique internationale 1957/58 en Antarctide. L'intensité du rayonnement solaire direct à Little America (44 m.) correspond à celle que l'on observe en juin à 3000 m. dans les Alpes; au Pôle Sud, à 2800 m. elle est équivalente à celle qui s'observe à 3000 m. dans les Alpes en décembre. Les mesures d'albédo au Pôle Sud et à Byrd-Station (1515 m) ont fourni une valeur moyenne de 89%, avec variations comprises entre 84 et 93%.

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With 1 Figure     

Impacts of different radiation schemes on the prediction of solar radiation and photovoltaic power

光伏发电系统的输出功率很大程度上取决于光伏面板所能接收到的太阳辐射量,到达地面的太阳辐射能量又受辐射传输过程影响。然而在工程实践中,数值模拟预报方案往往只采用一种辐射方案,导致太能辐射量和光伏发电功率的预测常不能满足预测精度。本文利用NCEP-NCAR的再分析数据作为初始场,以新疆区域为例选用多种辐射参数化方案进行组合模拟。通过算例分析后发现:不同的辐射参数化方案模拟结果差别很大,总辐射和预测功率的绝对误差分别为106.67 W m-2 and 3.5 MW。总辐射的平均绝对百分比误差范围为8.6%~17.3%,预测功率的平均绝对百分比误差范围为11.3%~20.2%。分析多种辐射参数化方案的模拟结果发现:RRTM/Dudhia和CAM辐射方案适合于晴天模拟     

Computing the flux of moisture from net radiation and soil wetness

A study has been made of the time evolution of the flux of moisture E over grassland. The parameterization of E has been examined in order to formulate an equation depending on the net radiation flux and on bulk parameters which depend on the daily average meteorological situation and soil conditions. In particular the gradient of soil moisture has been recognized as playing a fundamental role in the time evolution of E(t). A time-dependent equation is proposed to compute in a statistical sense the irrigation needs or to forecast the hourly values of E(t), the maximum value E ₀ and the time at which this maximum happens.     

On the estimation of long-wave radiation flux from clear skies

Summary Data from measurements of long-wave radiation at Barcelona were used to test the validity of several methods for computing this component of the radiation balance in clear sky conditions.Two types of formulae, the analytically derived formulae of Swinbank and Brutsaert 1 and 2 and the empirically obtained formulae of Brunt, Idso and Jackson and Idso 1 and 2 were used in the test.Most of these methods are derived for a particular location and utilize local empirical coefficients. However, there are several which have been considered more universal.Estimates by the two methods give approximately the same value when the screen level air temperature is above 0°C.In addition, the test for temperatures below 0°C shows several discrepancies between the observed and estimated values of long-wave atmospheric radiation. This fact suggests that modifications may be needed for both analytical and empirical formulae. However, since we have few measurements in the temperature regime below 0°C, this statement cannot be justified as a conclusion of this study.

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Zusammenfassung Es werden Daten der langwelligen atmosphärischen Strahlung bei Barcelona herangezogen, um verschiedene Methoden zur Bestimmung dieser Komponente der Strahlungsbilanz bei klarem Himmel zu vergleichen. Dazu werden zwei unterschiedliche Formeltypen, die analytischen nach Swinbank und Brutsaert (1 und 2) und empirische nach Brunt, Idso und Jackson sowie Idso (1 und 2) benützt.Von diesen Methoden wurden die meisten für einen bestimmten Ort entwickelt und verwenden daher lokale empirische Koeffizienten. Allerdings gibt es einige, die als allgemein verwendbar angesehen werden.Für beide Typen der Abschätzung ergeben sich für Lufttemperaturen über 0°C im Hüttenniveau ähnliche Werte. Bei Lufttemperaturen unter 0°C zeigen sich jedoch einige Unterschiede zwischen den beobachteten und geschätzten Werten der langwelligen atmosphärischen Strahlung. Das legt nahe, die Koeffizienten sowohl für die analytischen als auch die empirischen Formeln anzupassen. Leider war das auf Grund des geringen Datenmaterials bei Temperaturen unter 0°C innerhalb dieser Untersuchung nicht möglich.

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With 2 Figures     

日射仪器的温度特性

本文主要叙述广泛使用于气象、农业、能源、科研等部门测量太阳辐射的DFY-1型直接辐射表和DFY-2型天空辐射表的温度特性。     

Analysis of solar radiation over Egypt

Summary  The database utilized in this analysis consisted of daily sunshine duration and hourly global and diffuse radiation on a horizontal surface (for Matruh Cairo, and Aswan), and normal incidence beam radiation (for Cairo and Aswan only). Monthly-average hourly and daily values are reported for each of these three types of measured radiation, together with the calculated monthly-average daily values for the components of global radiation, horizontal beam and diffuse radiation. The monthly-average hourly and daily clearsky index values have also been calculated and analyzed. Monthly-average daily frequency distributions of the clearsky index values are reported for each month. The annual-average daily global irradiation values are 19.4, 18.67, and 21.78 MJ/m² and for diffuse irradiation they are 6.34, 6.65 and 6.23 MJ/m² for Matruh, Cairo and Aswan, respectively. For the normal incidence beam irradiation the annual-average daily values are 16.94 and 24.46 MJ/m² for Cairo and Aswan, respectively. The annual-average daily fractions of the direct component of horizontal global radiation are 0.70, 0.61 and 0.72 for the three stations, respectively. The annual-average daily values for the clearsky index are 0.585, 0.566, and 0.648, and the average frequency of clear days annually are 67.3, 42.3 and 77.6% respectively. The annual variations and trend analysis were analyzed for daily global, direct, and diffuse radiation on a horizontal surface, daily sunshine duration, and for the daily ratios G/G₀, and D/G for the stations Matruh, Cairo and Aswan. The distribution of these components of radiation and their ratios over the study stations in Egypt is also discussed. The results show that Egypt is characterized by relatively high average-daily radiation rates, both global and direct, and a relatively high frequency of clear days. Cairo, due to its urbanization and high pollution, has relatively low average-daily radiation rates, particularly in direct radiation, and the frequency of clear days. Received February 26, 1998 Revised February 4, 1999     

Dynamic behaviour of diffuse solar radiation

In the present experimental study, the dynamic properties of diffuse solar radiation have been assessed for both overcast and discrete clouds. It is shown that the Baseline Surface Radiation Network methodology can be accepted completely for studying diffuse radiation.     

吉林省太阳辐射变化规律及太阳能资源利用研究

为揭示吉林省的太阳能资源变化规律,利用线性回归分析、线性相关分析及M-K检验法对吉林省长春、延吉两个气象站点1960年以来的太阳总辐射资料进行研究。结果表明：吉林省的年平均太阳总辐射为4787.4 MJ/㎡•a,夏季太阳总辐射最大,春季次之,冬季最小。吉林省年平均太阳总辐射在波动中下降,且下降趋势不显著,20世纪60年代太阳总辐射较高,80年代达到最低值,90年代以后小幅度回升。春、秋、冬三季的太阳总辐射呈不同程度的下降趋势,冬季的下降趋势显著,夏季呈显著增加。吉林省年日照时数在空间分布上呈现出由西向东逐渐减少的地域分布差异;而在时间上也呈现出由春季到冬季依次减少的分布特征。吉林省的太阳能资源总量丰富,变化趋势不显著,这对于吉林省利用太阳能资源是十分有利的。     

Accuracy of CM-SAF solar irradiance incident on horizontal surface

The Climate Monitoring Satellite Application Facility (CM-SAF) provides estimates of global solar irradiance incident on horizontal surface at Earth surface. Measurements performed in 2010 at five Romanian meteorological stations are used to test the accuracy of the CM-SAF irradiance data. The dataset contains null solar global irradiance values, which cannot be explained by very large values of the zenith angle neither by overcast sky conditions. Sub-databases have been created. The database Z85 consists of irradiance data, without filtering and processing. The database Z85SIS+ remove all null irradiance values. For a given database, the root mean square error (RMSE) with respect to the ground-based measurements is rather similar for all stations, i.e. around 35 % for Z85 and 24 % for Z85SIS+. On average, the database Z85SIS+ has smaller mean bias error (MBE) than the database Z85, independent of the degree of cloudiness. For the database Z85, MBE (RMSE) ranges, depending on station, between ?9.4 and ?1.2 % (35.3 and 39.1 %). For database Z85SIS+, the MBE (RMSE) ranges, depending on station, between ?4.0 and 0.1 % (23.0 and 29.1 %). On overcast sky, we found for some stations MBE?=??0.1 % and RMSE?=?46.4 % when the database Z85SIS+ has been considered. The accuracy of the database Z85 is lower; we found MBE?=??7.0 % and RMSE?=?58.8 % as extreme cases.