Feister U, Jäkel E, Gericke K
Deutscher Wetterdienst, Meteorologisches Observatorium Potsdam, Germany.
Photochem Photobiol. 2002 Sep;76(3):281-93. doi: 10.1562/0031-8655(2002)076<0281:podsgu>2.0.co;2.
Daily values of solar global ultraviolet (UV) B and UVA irradiation as well as erythemal irradiation have been parameterized to be estimated from pyranometer measurements of daily global and diffuse irradiation as well as from atmospheric column ozone. Data recorded at the Meteorological Observatory Potsdam (52 degrees N, 107 m asl) in Germany over the time period 1997-2000 have been used to derive sets of regression coefficients. The validation of the method against independent data sets of measured UV irradiation shows that the parameterization provides a gain of information for UVB, UVA and erythemal irradiation referring to their averages. A comparison between parameterized daily UV irradiation and independent values of UV irradiation measured at a mountain station in southern Germany (Meteorological Observatory Hohenpeissenberg at 48 degrees N, 977 m asl) indicates that the parameterization also holds even under completely different climatic conditions. On a long-term average (1953-2000), parameterized annual UV irradiation values are 15% and 21% higher for UVA and UVB, respectively, at Hohenpeissenberg than they are at Potsdam. Daily global and diffuse irradiation measured at 28 weather stations of the Deutscher Wetterdienst German Radiation Network and grid values of column ozone from the EPTOMS satellite experiment served as inputs to calculate the estimates of the spatial distribution of daily and annual values of UV irradiation across Germany. Using daily values of global and diffuse irradiation recorded at Potsdam since 1937 as well as atmospheric column ozone measured since 1964 at the same site, estimates of daily and annual UV irradiation have been derived for this site over the period from 1937 through 2000, which include the effects of changes in cloudiness, in aerosols and, at least for the period of ozone measurements from 1964 to 2000, in atmospheric ozone. It is shown that the extremely low ozone values observed mainly after the eruption of Mt. Pinatubo in 1991 have substantially enhanced UVB irradiation in the first half of the 1990s. According to the measurements and calculations, the nonlinear long-term changes observed between 1968 and 2000 amount to +4%, ..., +5% for annual global irradiation and UVA irradiation mainly because of changing cloudiness and + 14%, ..., +15% for UVB and erythemal irradiation because of both changing cloudiness and decreasing column ozone. At the mountain site, Hohenpeissenberg, measured global irradiation and parameterized UVA irradiation decreased during the same time period by -3%, ..., -4%, probably because of the enhanced occurrence and increasing optical thickness of clouds, whereas UVB and erythemal irradiation derived by the parameterization have increased by +3%, ..., +4% because of the combined effect of clouds and decreasing ozone. The parameterizations described here should be applicable to other regions with similar atmospheric and geographic conditions, whereas for regions with significantly different climatic conditions, such as high mountainous areas and arctic or tropical regions, the representativeness of the regression coefficients would have to be approved. It is emphasized here that parameterizations, as the one described in this article, cannot replace measurements of solar UV radiation, but they can use existing measurements of solar global and diffuse radiation as well as data on atmospheric ozone to provide estimates of UV irradiation in regions and over time periods for which UV measurements are not available.
已对太阳全球紫外线（UV）B和UVA辐照度以及红斑辐照度的每日值进行参数化，以便根据日总辐照度和散射辐照度的日射强度计测量值以及大气柱臭氧来估算。利用德国波茨坦气象观测站（北纬52度，海拔107米）在1997 - 2000年期间记录的数据来推导回归系数集。针对独立的实测紫外线辐照度数据集对该方法进行验证，结果表明，对于UVB、UVA和红斑辐照度的平均值而言，该参数化方法能够提供更多信息。将参数化的每日紫外线辐照度与德国南部一个山区气象观测站（北纬48度，海拔977米的霍恩皮森贝格气象观测站）实测的紫外线辐照度独立值进行比较，结果表明，即使在完全不同的气候条件下，该参数化方法仍然适用。从长期平均值（1953 - 2000年）来看，霍恩皮森贝格的UVA和UVB参数化年紫外线辐照度值分别比波茨坦高15%和21%。德国气象局德国辐射网络28个气象站的日总辐照度和散射辐照度测量值以及欧洲臭氧监测卫星实验的柱臭氧网格值被用作输入数据，以计算德国境内紫外线辐照度日值和年值的空间分布估算值。利用自1937年以来在波茨坦记录的日总辐照度和散射辐照度每日值以及自1964年以来在同一地点测量的大气柱臭氧，得出了1937年至2000年该地点的紫外线辐照度日值和年值估算值，其中包括云量、气溶胶变化的影响，至少对于1964年至2000年的臭氧测量期而言，还包括大气臭氧变化的影响。结果表明，主要在1991年皮纳图博火山喷发后观测到的极低臭氧值在20世纪90年代上半叶显著增强了UVB辐照度。根据测量和计算结果，1968年至2000年期间观测到的非线性长期变化，年总辐照度和UVA辐照度主要由于云量变化而达到 +4%，……， +5%，而UVB和红斑辐照度由于云量变化和柱臭氧减少而达到 +14%，……， +15%。在山区站点霍恩皮森贝格，同期实测的总辐照度和参数化的UVA辐照度下降了 -3%，……， -4%，这可能是由于云的出现频率增加和光学厚度增大，而通过参数化得出的UVB和红斑辐照度由于云和气态臭氧减少的综合作用增加了 +3%，……， +4%。这里描述的参数化方法应该适用于具有类似大气和地理条件的其他地区，而对于气候条件显著不同的地区，如高山地区以及北极或热带地区，回归系数的代表性必须经过验证。这里强调，本文所述的参数化方法不能替代太阳紫外线辐射的测量，但它们可以利用现有的太阳总辐照度和散射辐照度测量数据以及大气臭氧数据，为没有紫外线测量数据的地区和时间段提供紫外线辐照度估算值。
