This study investigates atmospheric conditions’ influence on the mean and extreme characteristics of PM10 concentrations in Poznań during the period 2006–2013. A correlation analysis was carried out to identify the most important meteorological variables influencing the seasonal dynamics of PM10 concentrations. The highest absolute correlation values were obtained for planetary boundary layer height (r = −0.57), thermal (daily minimum air temperature: r = −0.51), anemological (average daily wind speed: r = −0.37), and pluvial (precipitation occurrence: r = −0.36) conditions, however the highest correlations were observed for temporal autocorrelations (1 day lag: r = 0.70). As regulated by law, extreme events were identified on the basis of daily threshold value i.e. 50 μg m−3. On average, annually there are approximately 71.3 days anywhere in the city when the threshold value is exceeded, 46.6 % of those occur in winter. Additionally, 83.7 % of these cases have been found to be continuous episodes of a few days, with the longest one persisting for 22 days. The analysis of the macro-scale circulation patterns led to the identification of an easy-to-perceive seasonal relations between atmospheric fields that favour the occurrence of high PM10 concentration, as well as synoptic situations contributing to the rapid air quality improvement. The highest PM10 concentrations are a clear reaction to a decrease in air temperature by over 3 °C, with simultaneous lowering of PBL height, mean wind speed (by around 1 m s−1) and changing dominant wind directions from western to eastern sectors. In most cases, such a situation is related to the expansion of a high pressure system over eastern Europe and weakening of the Icelandic Low. Usually, air quality conditions improve along with an intensification of westerlies associated with the occurrence of low pressure systems over western and central Europe. Opposite relations are distinguishable in summer, when air quality deterioration is related to the inflow of tropical air masses originating over the Sahara desert.

中文翻译：

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大气条件对波兰波兹南 PM10 浓度的影响

本研究调查了 2006-2013 年期间大气条件对波兹南 PM10 浓度平均和极端特征的影响。进行了相关分析以确定影响 PM10 浓度季节性动态的最重要气象变量。获得了行星边界层高度（r = -0.57）、热（每日最低气温：r = -0.51）、气象（每日平均风速：r = -0.37）和雨量（降水发生）的最高绝对相关值: r = -0.36) 条件，但是观察到最高相关性的时间自相关（1 天滞后：r = 0.70）。根据法律规定，极端事件是根据每日阈值（即 50 μg m-3）确定的。平均而言，每年大约有 71 个。超过阈值的城市任何 3 天，其中 46.6% 发生在冬季。此外，已发现这些病例中有 83.7% 是连续几天发作，最长的病例持续 22 天。对宏观环流模式的分析导致确定了有利于高 PM10 浓度出现的大气场之间的易于感知的季节性关系，以及有助于快速改善空气质量的天气情况。最高 PM10 浓度是对气温降低 3 °C 以上的明显反应，同时 PBL 高度降低，平均风速（约 1 m s-1）降低，主导风向从西向东发生变化。在大多数情况下，这种情况与东欧高压系统的扩张和冰岛低压的减弱有关。通常，空气质量状况会随着西欧和中欧低压系统出现而导致的西风加强而改善。在夏季，空气质量恶化与源自撒哈拉沙漠的热带气团的流入有关。