Antón Manuel, Cazorla Alberto, Mateos David, Costa Maria J, Olmo Francisco J, Alados-Arboledas Lucas
Departamento de Física, Universidad de Extremadura, Badajoz, Spain.
Departamento de Física, Instituto de Ciências da Terra, Escola de Ciências e Tecnologia, Universidade de Évora, Évora, Portugal.
Photochem Photobiol. 2016 Jan-Feb;92(1):215-9. doi: 10.1111/php.12539. Epub 2015 Nov 4.
This study focuses on the analysis of the sensitivity of UV erythemal radiation (UVER) to variations in the total ozone column (TOC) under different sky conditions at Granada (southeastern Spain). The sensitivity is studied both in relative terms by means of the Radiation Amplification Factor (RAF) and in absolute terms using the Ozone Efficiency (OE). These two variables are determined for diverse sky conditions characterized by the cloud cover information given by a sky camera (in oktas) and the cloud optical depth (COD) estimated from global solar radiation measurements. As expected, in absolute terms, the TOC variations cause substantially smaller UVER changes during completely overcast situations than during cloud-free cases. For instance, the OE (SZA = 30°, TOC = 290 DU) decreases from 0.68 mW m(-2) per unit of TOC (0 oktas) to 0.50 mW m(-2) per unit of TOC (8 oktas). However, the opposite is observed when the analysis is performed in relative terms. Thus, the RAF (determined for SZA cases below 80°) increases from 1.1 for cloud-free cases (0 oktas) to 1.4 for completely overcast situations (8 oktas). This opposite behavior is also found when both RAF and OE are analyzed as functions of COD. Thus, while the OE strongly decreases with increasing COD, the RAF increases as COD increases.
本研究聚焦于西班牙东南部格拉纳达不同天空条件下紫外线红斑辐射（UVER）对总臭氧柱（TOC）变化的敏感性分析。通过辐射放大因子（RAF）以相对方式研究敏感性，并用臭氧效率（OE）以绝对方式进行研究。这两个变量是针对不同天空条件确定的，这些条件由天空相机给出的云量信息（以奥克塔为单位）以及根据全球太阳辐射测量估算的云光学厚度（COD）来表征。正如预期的那样，从绝对角度来看，与无云情况相比，在完全阴天的情况下，TOC变化导致的UVER变化要小得多。例如，臭氧效率（太阳天顶角 = 30°，TOC = 290多布森单位）从每单位TOC（0奥克塔）的0.68毫瓦每平方米降至每单位TOC（8奥克塔）的0.50毫瓦每平方米。然而，当以相对方式进行分析时，观察到的情况则相反。因此，辐射放大因子（针对太阳天顶角低于80°的情况确定）从无云情况（0奥克塔）的1.1增加到完全阴天情况（8奥克塔）的1.4。当将辐射放大因子和臭氧效率都作为云光学厚度的函数进行分析时，也发现了这种相反的行为。因此，随着云光学厚度增加，臭氧效率大幅下降，而辐射放大因子则增加。
