Solar Radiation Climatology of Alaska
Solar Radiation Climatology of Alaska
复制标题
阿拉斯加的太阳辐射气候学
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Gerd Wendler
中科院分区：
文献类型：
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作者：
D. Dissing;Gerd Wendler
摘要阿拉斯加只有六个地点有持续一年以上的全球辐射数据。对于一个覆盖1.5×10&6 平方公里、横跨至少三个气候带的州来说，这是一个极其稀少的覆盖范围。然而，云观测可以从18个观测站获得。我们使用部分云量和云类型数据来模拟全球辐射，从而获得更完整的阿拉斯加辐射覆盖范围。这个扩展的数据集允许分析地理和季节趋势。基于Haurwitz的半经验方法，开发了一个简单的1层模式，考虑了云类型和部分覆盖率的变化。该模式预测的年全球辐射通量将在观测值的2-11%以内。估计的月平均值给出了大约6%的测量值的平均准确度。今年前四个月的估计与观察结果吻合得很好，但后四个月的估计结果就不那么符合了。地表反照率的变化可能解释了这种偏差。在此之前，来自国家可再生能源实验室(NREL)的1993年国家太阳辐射数据库(NSRDB)模拟了16个阿拉斯加站的全球辐射数据。虽然NREL模型更加完整和复杂，但需要更多的输入参数，这在阿拉斯加是不可用的。因此，我们认为，我们的模型是基于云-辐射关系，并专门针对阿拉斯加的条件进行调整的，对该地区产生了更好的结果。将年度全球太阳辐射通量测量结果与基于国际卫星云气候学项目(ISCCP)数据的全球覆盖模型的结果进行了比较。在气候和地理环境的背景下，提出并讨论了阿拉斯加全球辐射的季节和年平均空间分布的等高线图。
Summary There are only six locations in Alaska for which global radiation data of more than a year in duration are available. This is an extremely sparse coverage for a state which covers 1.5×10&6 km2 and stretches over at least three climatic zones. Cloud observations are, however, available from 18 stations. We used fractional cloud cover and cloud type data to model the global radiation and thus obtain a more complete radiation coverage for Alaska. This extended data set allowed an analysis of geographic and seasonal trends.A simple 1-layer model based on Haurwitz’s semi-empirical approach, allowing for changes in cloud type and fractional coverage, was developed. The model predicts the annual global radiation fluxes to within 2–11% of the observed values. Estimated monthly mean values gave an average accuracy within about 6% of the measurements. The estimates agree well with the observations during the first four months of the year but less so for the last four. Changing surface albedo might explain this deviation.Previously, the 1993 National Solar Radiation Data Base (NSRDB) from the National Renewable Energy Laboratory (NREL) modeled global radiation data for 16 Alaskan stations. Although more complete and complex, the NREL model requires a larger number of input parameters, which are not available for Alaska. Hence, we believe that our model, which is based on cloud-radiation relationship and is specifically tuned to Alaskan conditions, produces better results for this region. Annual global solar radiation flux measurements are compared with results from global coverage models based on the International Satellite Cloud Climatology Project (ISCCP) data. Contour plots of seasonal and mean annual spatial distribution of global radiation for Alaska are presented and discussed in the context of their climatic and geographic settings.