Decline of fog, mist and haze in Europe over the past 30 years
Decline of fog, mist and haze in Europe over the past 30 years
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DOI：
10.1038/ngeo414
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发表时间：
2009-02
影响因子：
18.3
通讯作者：
R. Vautard;P. Yiou;G. V. Oldenborgh
中科院分区：
文献类型：
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作者：
R. Vautard;P. Yiou;G. V. Oldenborgh
自20世纪中叶以来，太阳表面辐射经历了年代际变化，产生了全球“变暗”和“变亮”效应。这些变化可能是由气溶胶负荷和云层的变化引起的，但所涉及的详细过程尚未确定。在欧洲，自20世纪80年代以来显著的太阳辐射增加被认为是造成观测到的大面积大陆变暖的原因，但这种贡献尚未被量化。在这里，我们分析了水平能见度的多年数据，发现在过去的30年里，欧洲所有季节和所有能见度范围在0到8公里之间的低能见度条件（如雾、薄雾和霾）的频率都有所下降。这种下降在空间和时间上都与二氧化硫排放的趋势相关，表明空气质量的改善做出了重大贡献。从统计数据上看，将当地能见度变化与温度变化联系起来，我们估计低能见度条件的减少可能对欧洲最近白天变暖的平均贡献率约为10-20%，对东欧变暖的贡献率约为50%。过去几十年来，欧洲在空气质量和能见度方面已经取得了很大的改善，这可能意味着未来低能见度事件发生频率的减少将是有限的，这可能导致区域变暖的速度放缓。
Surface solar radiation has undergone decadal variations since the middle of the twentieth century, producing global ‘dimming’ and ‘brightening’ effects,. These variations presumably result from changes in aerosol burden and clouds, but the detailed processes involved have yet to be determined. Over Europe, the marked solar radiation increase since the 1980s is thought to have contributed to the observed large continental warming, but this contribution has not been quantified. Here we analyse multidecadal data of horizontal visibility, and find that the frequency of low-visibility conditions such as fog, mist and haze has declined in Europe over the past 30 years, for all seasons and all visibility ranges between distances of 0 and 8 km. This decline is spatially and temporally correlated with trends in sulphur dioxide emissions, suggesting a significant contribution of air-quality improvements. Statistically linking local visibility changes with temperature variations, we estimate that the reduction in low-visibility conditions could have contributed on average to about 10–20% of Europe’s recent daytime warming and to about 50% of eastern European warming. Large improvements in air quality and visibility already achieved in Europe over the past decades may mean that future reductions in the frequency of low-visibility events will be limited, possibly leading to less rapid regional warming.