To evaluate air quality in Athens (Greece), hourly concentrations of PM 10 , NO 2 , O 3 , and CO from an urban background monitoring station and a suburban sampling site, covering the years 2014–2018, were used for the calculation of individual daily air quality indices (AQIs), reflecting the impact of each pollutant on air quality. Individual AQIs were then integrated in a previously reported formula for the computation of a daily aggregate AQI (AQI agg ) expressing the overall air stress. According to the results of AQI agg , a generally moderate air quality was estimated in Athens; however, an increased likelihood of extreme AQI agg episodes was calculated during the warm period (16 April–15 October), due to the combination of enhanced PM 10 and O 3 concentrations. Approximately 83% of AQI agg episodes occurred during the warm period and only 17% in cold period (16 October–15 April). Peaks of AQI agg in cold period were primarily related to desert dust intrusions from North Africa. AQI PM10 and AQI O3 were the primary contributors to AQI agg , whereas AQI NO2 and AQI CO remained at low levels. AQI PM10 and AQI O3 had the highest contribution to AQI agg on 72% and 28% of total days respectively. Atmospheric circulation patterns produced by a K-means cluster analysis procedure revealed that extended low pressure areas centered over the UK were associated with dust importation in Athens due to the triggering of southwestern airflows by the cyclonic activity. Strong correlations between the individual and aggregate AQIs calculated at the urban background and the suburban sampling site were found, indicating relatively uniform air quality conditions inside the Athens basin. Mean annual AQI agg values at the suburban station for the years 2001–2018 showed a gradual amelioration and stabilization of air quality in Athens after 2008, related to the status of Greek economy and depollution measures.

中文翻译：

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实施综合指数以阐明大气天气条件对希腊雅典空气质量的影响

为了评估雅典（希腊）的空气质量，城市背景监测站和郊区采样点的 PM 10 、NO 2 、O 3 和 CO 每小时浓度（涵盖 2014-2018 年）被用于计算个体每日空气质量指数 (AQI)，反映每种污染物对空气质量的影响。然后将单个 AQI 整合到先前报告的公式中，用于计算表示整体空气压力的每日总 AQI (AQI agg)。根据 AQI agg 的结果，雅典的空气质量大致中等；然而，由于 PM 10 和 O 3 浓度升高，在温暖时期（4 月 16 日至 10 月 15 日）计算出极端 AQI agg 事件的可能性增加。大约 83% 的 AQI agg 事件发生在温暖期，只有 17% 发生在寒冷期（10 月 16 日至 4 月 15 日）。寒冷时期AQI agg的峰值主要与来自北非的沙漠尘埃入侵有关。AQI PM10 和 AQI O3 是 AQI agg 的主要贡献者，而 AQI NO2 和 AQI CO 保持在低水平。AQI PM10 和 AQI O3 对 AQI agg 的贡献率最高，分别占总天数的 72% 和 28%。由 K 均值聚类分析程序产生的大气环流模式表明，由于气旋活动触发了西南气流，以英国为中心的扩展低压区与雅典的灰尘输入有关。发现在城市背景和郊区采样点计算的个体 AQI 和总体 AQI 之间存在很强的相关性，表明雅典盆地内部的空气质量状况相对均匀。2001-2018 年郊区站的年平均 AQI agg 值表明，2008 年后雅典的空气质量逐渐改善和稳定，这与希腊经济状况和去污染措施有关。