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1.
为了保证观测数据的准确性,必须建立全面的辐射表性能指标检测体系,对辐射仪器的性能指标进行测试.依据世界气象组织(WMO)和ISO 9060的相关规定,在总日射表检定规程的基础上,试验和研究总日射表的零偏移、分辨率、方向响应、非线性误差等性能指标.光电型总日射表与光热型总日射表相比有明显的光谱选择性,在光谱范围、响应时间、测量原理、结构材料等方面均存在不同,因此二者的测量方法也存在差异.在非线性测试中,双光源叠加法被用以取代传统的太阳模拟器法.研究表明,选择总日射表的方向响应误差来指定仪表在各方向上的性能以及规范总日射表的分类,比用余弦响应误差和方位响应误差有更多的优点.  相似文献   

2.
试论总辐射的气候学计算方法   总被引:50,自引:0,他引:50  
翁笃鸣 《气象学报》1964,34(3):304-315
本文通过对现有各种总辐射计算公式的讨论,证实了Q=Q_0f(S_1,n)及Q=S_0φ(S_1,n)的一致性;讨论了常见的沙文诺夫-易斯川姆式中系数K的物理意义及其影响因子;分析了在我国具体条件下,日照百分比和平均总云量之和不等于1的原因及其年变程。最后,根据我国日射资料(1958—1960年)各自分别地得出计算月平均总辐射日总量Q,直接辐射量S’和散射辐射量D的经验式,然后使之满足Q=S’+D,并以此相互验证各自的计算精确性。  相似文献   

3.
光合有效辐射(PAR)的气候学研究   总被引:18,自引:1,他引:18  
根据我国8个地区11个测点的2878组直接辐射的分光测量资料,得到了计算直接辐射中0.4—0.7微米波段光合有效辐射(PAR)的经验公式。利用这个公式结合8个有地区代表性台站的日射资料,计算了1,4,7,10各月的直接辐射、散射辐射和总辐射中PAR所占的比例,结果表明。它们分别是0.394-0.04,0.49±0.04和0.444±0.03。我国以往的研究者在计算PAR总辐射时都把比例值取得偏高了。  相似文献   

4.
为认识和提高光合有效辐射 (波长为400~700 nm) 的测量精度,对国内外5种常用的光合有效辐射表的灵敏度、余弦响应、非线性、温度依赖性、光谱响应等性能进行了测试和分析。结果表明: 5种光合有效辐射表 (简称光合表) 的非线性误差均在1%以内; 3种光合表 (PAR LITE,LI-190和FS-PR) 的余弦误差均小于10%,温度系数均小于0.3%/℃,2种光合表 (TRT-5和HSC-FPH-1) 的余弦误差明显偏大,温度系数小于0.5%/℃。2种光合表 (PAR LITE和LI-190) 的光谱响应曲线接近于理想光谱,而其余3种光合表与理想光谱曲线偏离较大。在自然光下的一致性比对测量结果显示,5种光合表测量的辐射量与标准值的误差均在5%以内,但综合评价后认为,3种光合表 (PAR LITE,LI-190和FS-PR) 的性能明显优于其他2种光合表 (TRT-5和HSC-FPH-1)。该结果可为气象观测业务选型提供参考。  相似文献   

5.
香河地区光合有效辐射的测量和计算   总被引:2,自引:1,他引:1       下载免费PDF全文
2004年9月12日—2006年10月31日,在河北省香河县对太阳辐射(包括光合有效辐射PAR、可见光辐射VIS和总辐射Q等)、气象参数等进行了综合测量,初步得到了PAR、VIS等的变化特征。观测表明,小时累计之比PAR/Q、VIS/Q、PAR/VIS相对稳定,2004—2006年的平均值分别为2.164、0.434 mol•MJ-1和4.967 mol•MJ-1,同时它们表现出明显的日、逐日和季节变化特征,并受到水汽、气溶胶、云等因素的影响。建立了实际天气条件计算PAR、VIS小时累计值的经验公式以及PAR与VIS转换关系式,计算值与观测值符合得较好。在考虑水汽和散射因子时,PAR、VIS计算值与观测值的相对偏差分别为9.9%和10.8%。限于实际情况,也可以只考虑水汽因子的作用来计算PAR和VIS小时累计值,它们的相对偏差分别为11.1%和11.8%。对于PAR、VIS的传输和计算来说,水汽因子的作用至关重要。散射因子的作用虽然弱于水汽因子,但它的作用不容忽视。  相似文献   

6.
华北地区光合有效辐射的计算方法研究   总被引:6,自引:0,他引:6       下载免费PDF全文
2004年9月—2006年10月,选择华北地区的4个观测站开展了太阳辐射(光合有效辐射PAR、可见光辐射VIS、总辐射Q等)、气象参数等的综合测量,得到了PAR、VIS等的变化特征,结果表明:PAR/Q、VIS/Q、PAR/VIS相对稳定,有明显的日、逐日和季节变化,并受到水汽、散射因子、云等因素的影响。2004—2006年禹城、栾城、香河、兴隆地区VIS/Q,PAR/Q和PAR/VIS的平均值分别为0.39,1.95 mol/MJ和4.97 mol/MJ;0.39,1.94 mol/MJ和4.95 mol/MJ;0.43,2.16 mol/MJ和4.97 mol/MJ;0.42,2.03 mol/MJ和4.89 mol/MJ。建立了计算华北地区实际天气PAR、VIS小时累计值的经验公式及PAR与VIS转换关系式,计算值与观测值符合得都比较好。考虑水汽和散射因子时,PAR、VIS计算值与观测值的相对偏差分别为13.0%、12.4%。由于某些站点可能缺少直接或散射辐射,也可以只考虑水汽因子,此时,PAR、VIS的相对偏差分别为13.2%、12.8%。对于PAR、VIS的传输和计算来说,水汽因子的作用最为重要;散射因子的作用虽弱于水汽因子,但也不应该忽视。  相似文献   

7.
近年来,在苏联热量平衡的研究中,曾利用沙文诺夫-昂斯川姆经验公式计算地表面的总辐射:Q=90[1-(1-k)n].(1)式中Q和Q_0分别为实际情况下和晴空情况下的总辐射;k为全天有云时Q与Q_0的比值,这里只考虑了年平均k值随緯度的变化;n为以分数表示的平均总云量,通常利用该公式确定总辐射。月平均值时,误差为10%;年平均误差小于5%。  相似文献   

8.
利用2005年7月-2006年10月在山东禹城对太阳辐射(包括光合有效辐射PAR、可见光辐射VIS、总辐射Q等)、气象要素等进行的4次综合观测资料,初步得到了朋R,VIS的日、季节变化特征并对其进行了分析,结果表明:各辐射的小时累计之比vIS/Q,PAR/Q,PAR/VIS相对稳定,其平均值分别为0.39,1.95(mol/MJ),4.97(mol/MJ),但它们均有明显的日、逐日、季节变化,并受水汽、气溶胶、云等因素的影响。同时建立了实际天气PAR,VIS的小时累计经验公式及其转换关系,计算值与观测值均比较接近。当考虑水汽和散射因子时,PAR,VIS的计算值与观测值的相对偏差分别为11.1%,10.6%。限于实际情况,可以只考虑水汽因子的作用来计算PAR和VIS的小时累计值,它们的相对偏差分别为13.3%,12.6%。水汽因子对于PAR,VIS的传输和计算具有重要作用。  相似文献   

9.
关于总日射表的热稳定时间   总被引:1,自引:1,他引:1       下载免费PDF全文
通过对各种型号的总日射表的研究,发现被测总日射表的预热时间不同对测量结果有很大的影响。这被称之为总日射表的热稳定时间。并建议凡用总日射表测量时,应等待5分钟,更精确的测量工作甚至应延长到10—20分钟。  相似文献   

10.
1.前言近年来,由于地面热平衡的能量问题,对正确了解地面日射量的分布和时间变化的要求提高了,并已在包括实验观测等许多方面实施日射量的观测。自设计埃斯屈朗补偿日射计(直接日射计)以来,已有90年历史,其精度为1%。然而,若用作水平面总日射观测,则不可避免产生5%左右的误差,有时误差超过20%。这是1974年和1975年的气团变性观测(AMTEX)的情况。从分析研究九州地方常规观测的日射量资料发现,在日本日射量最多的地方宫崎,晴天中午的水平面总日射量超过大气顶的值(这些例子将在后面给出)。因此,在当时的热量收支分析中,还不能完全利用常规观测资料。今后,将在多方面积累水平面总日射量资料,所  相似文献   

11.
Summary ?The relationship between global photosynthetically active radiation (PAR) and global solar radiation is studied with a 2-year data archive of hourly values HPAR and HSW of these irradiances obtained at Athalassa, Cyprus. These data are used to determine the temporal variability of HPAR and its dependence on sky conditions. The seasonal variation of the ratio HPAR/HSW obtained from daily data ranges from 0.456 (during summer) to 0.451 (during winter) with an annual mean value of 0.454. The ratio increases from 0.454 to 0.467 (daily values) or from 0.460 to 0.501 (hourly values), as sky conditions change from clear to overcast. Finally, the effect of aerosol content on the HPAR/HSW ratio is found to incur substantial changes in the PAR fraction. Received June 27, 2001; revised April 17, 2002; accepted May 18, 2002  相似文献   

12.
上海地区地面太阳紫外辐射的观测和分析   总被引:21,自引:0,他引:21  
通过对上海地区2001~2003年地面太阳总辐射和紫外辐射观测资料的分析表明:(1)上海地区太阳辐射和紫外辐射年总量分别为4487.1MJ/m^2和149.6MJ/m^2。(2)紫外辐射的季节变化特征十分明显,夏半年(4-9月)各月极大紫外辐射强度远大于冬半年(10月~次年3月),7月份最强,12月份最弱。(3)不同天气条件下,紫外辐射日变化显示出明显的差异,晴天强且稳定,多云天气波动较大,阴天则次之。(4)紫外辐射占总辐射的比例(η)也显示冬半年低,夏半年高的分布特征。(5)影响上海地区到达地面紫外辐射的主要因子有:太阳高度角的大小大致决定了到达地面紫外辐射的强弱,两者具有相近的年变化趋势;云、雨等天气类型是影响紫外辐射的重要因子;大气能见度对紫外辐射也有比较明显的影响。  相似文献   

13.
Integrated observations were made of solar irradiance (including photosynthetically active radiation (PAR), visible radiation (VIS), global radiation (G), etc.), and meteorological parameters at 4 stations in North China between September, 2004 and October, 2006. The ratios of hourly sum of PAR to G (H PAR/H), VIS to G (H VIS/H), and PAR to VIS (H PAR/H VIS) varied smoothly but exhibited significant diurnal, daily, seasonal variations, and were influenced by several factors, such as water vapor, cloud, haze, etc. The objective of this paper is to develop empirical formulas for estimation of hourly and daily sums of PAR and VIS and their relationship under all sky conditions in North China. The calculated PAR and VIS were in agreement with measured values, the relative biases were 13.0?% and 12.4?% for hourly sums, 9.9?% and 9.0?% for daily values, respectively.  相似文献   

14.
利用2005~2011年的太阳辐射观测资料分析三江平原地区光合有效辐射(Qp)的时间变化特征及其与总辐射(Rs)比值(Qp/Rs)的变化规律,结果表明,Qp与Rs具有相同的季节变化特征;Qp日累计值的变化范围为60.47~0.11 mol m-2 d-1,年均值为23.76 mol m-2 d-1。Qp/Rs的变化范围为1.52~2.07 mol MJ-1,年均值为1.91 mol MJ-1。Qp/Rs和Qp季节变化一致,两者都是夏季最大,春秋次之,冬季最小。通过利用2011年的Qp观测数据、大气质量数与晴空指数的相互关系,建立了适合于估量三江地区Qp的经验方程,估算值与观测值的相对误差在5.7%以内。  相似文献   

15.
Abstract

The measurement of radiation fluxes suffers from inaccuracies at low solar elevations and this poses a problem for determining the snow albedo at high latitudes. From the data of Resolute, NWT, three situations were observed: (1) an often‐reported situation when albedo decreases with increasing solar elevation, (2) an inverse situation when albedo increases with increasing solar elevation and (3) no obvious relationship. There were also cases when albedo exceeded 100%. The possible causes for such anomalous conditions or for erroneous albedos include instrument response deviating from the cosine law, instrument tilt, sensing of the sun by the inverted pyranometer and change in the spectral quality of incoming radiation with changing solar height. However, omission of the radiation values measured during the period of low solar elevation will not seriously affect the prediction of snowmelt. In this note, we have identified the anomalies and suggested possible causes; but further investigations are required to verify the causative mechanisms.  相似文献   

16.
The distribution of solar radiation over the Earth's surface   总被引:4,自引:0,他引:4  
Summary Records of total solar radiation measured on a horizontal surface (Q) on a monthly basis and of more than three years' duration are available for 88 stations. The stations are mainly concentrated in North America and Europe, and it is not possible to determine the global distribution of radiation directly from these records. Solar radiation and mean cloud amount (C) were therefore related by the quadratic regressionQ=Q A (0.803–0.340C–0.458C 2), whereQ A is the maximum possible radiation in the absence of an atmosphere (Angot's values) and the values ofC were obtained from the maps printed inShaw's Manual of Meteorology.Using the known distribution ofQ A andC, values ofQ were calculated by use of the equation above for each 5° intersection of latitude and longitude over land, and for each 10° intersection over sea. Isopleths ofQ for each successive 50 gcal/cm2 day are shown on the 12 monthly maps on which the distribution of radiation over the earth's surface is illustrated. Attention is drawn to certain features of these maps, in particular to the occurrence and movement of zones of high radiation, and a comparison is made of estimated and recorded radiation for twelve stations.
Zusammenfassung Registrierungen der Monatswerte der Globalstrahlung auf Horizontalfläche (Q) über mindestens drei Jahre liegen für 88 Stationen vor; diese sind vorwiegend auf Nordamerika und Europa konzentriert, und es ist daher nicht möglich, auf Grund davon die gesamte Strahlungsverteilung über die Erde zu bestimmen. Es wird nun mit Hilfe der quadratischen RegressionsgleichungQ=Q A (0.803–0.340C–0.458C 2) eine Beziehung zwischen GlobalstrahlungQ und mittlerer BewölkungC aufgestellt, woQ A den Maximalwert der Globalstrahlung bei Fehlen einer Atmosphäre bedeutet und die Konstanten nachAngot und die Bewölkungsdaten nachShaw angenommen sind.Auf Grund der Verteilung vonQ A undC wurden mit Hilfe der angegebenen Gleichung für jeden Bereich von je 5° Länge und Breite über Land von je 10° über Meer die Werte der Globalstrahlung berechnet. Isoplethen der Globalstrahlung für Stufen von je 20 gcal/cm2 Tag sind in 12 Monatskarten wiedergegeben, auf denen die Strahlungsverteilung über die Erde dargestellt ist. Einige Resultate dieser Karten werden besprochen, im speziellen das Auftreten und die Verschiebung der Zonen hoher Strahlung; zudem wird für 12 Stationen eine Vergleichung zwischen der berechneten und der registrierten Strahlung durchgeführt.

Résumé On possède des enregistrements de 88 stations pour les sommes mensuelles du rayonnement global sur une surface horizontale (Q) pour des périodes d'au moins 3 ans. Ces stations sont concentrées essentiellement en Amérique du Nord et en Europe ce qui ne permet pas d'en déduire la répartition du rayonnement global sur toute la terre. Pour cette raison l'auteur établit, au moyen de l'équation carrée de régressionQ=Q A (0.803–0.340C–0.458C 2), une relation entre le rayonnement globalQ et la moyenne de la nébulositéC, oùQ A représente la valeur maximale du rayonnement global sans atmosphère et où les constantes sont données selonAngot, la nébulosité selonShaw.A partir de la répartition deQ et deC et à l'aide de la formule précédente l'auteur a calculé les valeurs du rayonnement global pour des surfaces de 5° de latitude et de longitude sur terre et de 10° sur mer. Des isoplèthes représentent le rayonnement global par échelons de 50 gcal/cm2 jour, sur 12 cartes mensuelles qui illustrent sa répartition sur toute la terre. L'auteur discute encore divers résultats de ces cartes, en particulier l'apparition et le déplacement des zones de fort rayonnement, et compare encore pour 12 stations les résultats obtenus par le calcul et par enregistrement.


With 14 Figures  相似文献   

17.
Daily rainfall and temperature data were extracted from the multi-ensemble HadRM3H regional climate model (RCM) integrations for control (1960–1990) and future (2070–2100) time-slices. This dynamically downscaled output was bias-corrected on observed mean statistics and used as input to hydrological models calibrated for eight catchments which are critical water resources in northwest England. Simulated daily flow distributions matched observed from Q95 to Q5, suggesting that RCM data can be used with some confidence to examine future changes in flow regime. Under the SRES A2 (UKCIP02 Medium-High) scenario, annual runoff is projected to increase slightly at high elevation catchments, but reduce by ~16% at lower elevations. Impacts on monthly flow distribution are significant, with summer reductions of 40–80% of 1961–90 mean flow, and winter increases of up to 20%. This changing seasonality has a large impact on low flows, with Q95 projected to decrease in magnitude by 40–80% in summer months, with serious consequences for water abstractions and river ecology. In contrast, high flows (> Q5) are projected to increase in magnitude by up to 25%, particularly at high elevation catchments, providing an increased risk of flooding during winter months. These changes will have implications for management of water resources and ecologically important areas under the EU Water Framework Directive.  相似文献   

18.
Summary ?Using the data of 6 automatic heat balance observation (AWS) stations and a data set of 52 surface observation stations over the Qinghai-Tibetan Plateau (“the Plateau”) and surroundings, the horizontal distribution is studied of “apparent atmospheric heat sources” 〈Q 1〉 and of “apparent atmospheric moisture sinks” 〈Q 2〉. The AWS stations were established during the period May to August 1998 of the Tibetan Plateau Meteorological Experiment (second TIPEX) by a cooperation of China and Japan. For this period the Plateau mean of 〈Q 1〉 is positive. Its value of 74 W/m2 is a little greater than a climate value and than values from MONEX and the first TIPEX in 1979, respectively. Also the corresponding 〈Q 2〉 is positive. Hence during that time the Plateau is a heat source and a moisture sink. A day-to-day change of 〈Q 1〉 and 〈Q 2〉 is more pronounced over the middle and east part of the Plateau than over the west part. Diagnostics accompanied by numerical simulations are used to study the daily relationship between 〈Q 1〉 over the Plateau and the weather over China and Asia for this summer. The results suggest that 〈Q 1〉 may affect precipitation over northern China and position of the west Pacific subtropical high. Abnormal southward retreat of this Pacific high seems to have caused the second flood over the middle and lower Yangtse river basin in July. Received May 20, 2001; revised February 2, 2002  相似文献   

19.
Summary Relationships between photosynthetically active radiation (PAR) and solar radiation (SR) and between diffuse radiation and global radiation at Bloemfontein, South Africa were investigated. The ratio of PAR to SR (PAR/SR) has been reported from many places in the northern hemisphere, but there were not many PAR/SR measurements documented from the southern hemisphere, including the study region. Based on the present observations, mean PAR/SR in the region (0.48) was not exceptionally different from other reported data (0.45–0.50). The effects of sky condition on PAR/SR were also investigated and confirmed the previous findings. PAR/SR increased as the clearness index (KT=ratio of global to extraterrestrial SR) decreased, as sky conditions varied from clear to cloudy. Thus, PAR/SR can be a simple function of the clearness index (the global PAR model). In this study, PAR/SR was explained by a quadratic function of KT. For the relationship between diffuse and global radiation, a simple linear threshold diffuse PAR model, as a linear function of KT, was proposed for the study region using long-term data of diffuse and global SR. Using the previous findings on the relationship between the ratio of diffuse to global SR (KSR) and the ratio of diffuse to global PAR (KPAR), at high KT, KPAR can be estimated as 30% higher than KSR, while at low KTKPAR is equivalent to KSR.  相似文献   

20.
Summary Measurements of spectral ultraviolet irradiance require spectroradiometers with high resolution and stability, and well known behavior of the instrument. A UV-spectrophotometer is described and methods of calibrations are shown. A set of measurements in the Utah Rocky Mountains (Snowbird-Hidden Peak, in 3300 m elevation) compared to those at the Wasatch Front (Logan, 1400 m) is discussed. Several sets of measurements are used to show the effect of solar zenith angle, elevation and cloudcover on direct solar and diffuse irradiance.At the time of the instrument design and measurements all were at Utah State University, Department of Soil Science and Biometeorology, Logan, Utah.With 11 Figures  相似文献   

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