Atmospheric Sounding Station, El Arenosillo Observatory, Atmospheric Research and Instrumentation Branch, National Institute for Aerospace Technology (INTA), Mazagón, Huelva, Spain.
Universidad de Castilla-La Mancha, Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Ciudad Real, Spain; Universidad de Castilla-La Mancha, Instituto de Investigación en Combustión y Contaminación Atmosférica, Camino de Moledores s/n, Ciudad Real, Spain.
Sci Total Environ. 2019 Nov 25;693:133587. doi: 10.1016/j.scitotenv.2019.133587. Epub 2019 Jul 25.
We report the evolution of tropospheric NO over the south-east of the Iberian Peninsula from 2005 to 2017. We have used hourly NO levels measured at air-quality stations in urban and suburban environments. Annual averages ranged between 14 and 45 μg m, with peaks above 200 μg m. A monthly variation was observed, with higher concentrations in cold months (40-60 μg m) and lower levels in the warm season (13-17 μg m). A diurnal pattern was found in urban and suburban areas. The upward trend in NO observed during the whole period contrasts with the upward trend reported in 2013-2017. The NO tropospheric column levels measured by the Ozone Monitoring Instrument over the Iberian Peninsula indicated a similar behaviour; nevertheless, the largest Spanish metropolitan areas did not show this increase. The mean sea level pressure and wind field data of ERA5 (European Centre for Medium-Range Weather Forecasts) were used to investigate the weather conditions, the NO outputs of the Copernicus Monitoring Services being used for the assessment of the NO spatial distribution. NO regional events, with concentrations in the range 140-150 μg m, and which occurred both in the winter and summer season under anticyclonic conditions, are also described. A local origin is identified in winter, whereas in summer, they are associated with a high-pressure system that blocks Mediterranean outflows towards the Atlantic Ocean. The high NO levels are attributed mainly to two factors: i) local emissions, rather than contributions from the western Mediterranean (or even North Africa), and ii) an increase in the pressure gradient between the Atlantic and the Mediterranean pressure systems, associated with a decrease in wind speed, was found during the last five years compared with the previous eight. Meteorological and chemical changes in mid-latitudes associated with global warming should also be investigated in the future.
我们报告了 2005 年至 2017 年期间伊比利亚半岛东南部对流层 NO 的演变。我们使用了城市和郊区空气质量站测量的每小时 NO 水平。年平均值在 14 到 45μg/m 之间，峰值超过 200μg/m。观察到每月的变化，冷月份（40-60μg/m）浓度较高，暖季（13-17μg/m）水平较低。在城市和郊区地区发现了昼夜模式。整个时期观察到的 NO 上升趋势与 2013-2017 年报告的上升趋势形成对比。臭氧监测仪器在伊比利亚半岛测量的 NO 对流层柱水平也表现出类似的行为；然而，最大的西班牙大都市区并没有显示出这种增长。使用欧洲中期天气预报中心（欧洲中期天气预报中心）的平均海平面压力和风向数据来研究天气条件，使用哥白尼监测服务的 NO 输出来评估 NO 的空间分布。还描述了冬季和夏季反气旋条件下发生的浓度在 140-150μg/m 范围内的 NO 区域事件。在冬季确定了本地来源，而在夏季，它们与阻止地中海流出流向大西洋的高压系统有关。高 NO 水平主要归因于两个因素：i）本地排放，而不是来自西地中海（甚至北非）的贡献，以及 ii）与风速下降相关的大西洋和地中海压力系统之间的压力梯度增加，与过去五年相比，前八年发现。未来还应研究与全球变暖相关的中纬度的气象和化学变化。
