Aerosol climatology and planetary boundary influence at the Jungfraujoch analyzed by synoptic weather types
Aerosol climatology and planetary boundary influence at the Jungfraujoch analyzed by synoptic weather types
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DOI：
10.5194/acp-11-5931-2011
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发表时间：
2011-06
影响因子：
6.3
通讯作者：
M. Coen;E. Weingartner;M. Furger;S. Nyeki;A. Prévôt;M. Steinbacher;U. Baltensperger
中科院分区：
文献类型：
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作者：
M. Coen;E. Weingartner;M. Furger;S. Nyeki;A. Prévôt;M. Steinbacher;U. Baltensperger
摘要。本文分析了14年来在少女峰（JFJ, 3580 m a.s.l）测量的气象参数、气溶胶变量（吸收和散射系数、气溶胶数浓度）和微量气体（CO、NOx、SO2）作为不同天气类型的函数。阿尔卑斯山天气统计（AWS）的schepp天气类型（SYNALP）分类被用来定义整个瑞士地区的天气气象。通过气溶胶年周期推导出各天气类型对气溶胶浓度的季节贡献，通过日周期估算出行星边界层对气溶胶浓度的影响。由于气溶胶被降水清除，CO浓度的日循环也被用于识别被污染的气团。SO2和NOx浓度分别作为新颗粒形成和生长的前驱示踪剂。12 - 3月间平流天气类型和4 - 9月间对流、反气旋和对流无风天气类型的气溶胶光学参数和数量浓度的负荷均有所增加。该研究证实了JFJ冬季主要受自由对流层影响，夏季主要受PBL注入气流的影响。然而，在平流天气类型中，冬季JFJ完全受对流层自由气团的影响，而在下沉天气类型中，夏季夜间也主要受PBL的影响。在这两种极端情况之间，PBL对JFJ的影响取决于一年中的时间和天气类型。通过比湿度和CO的相对增加来估计输送到JFJ的PBL空气的比例。
Abstract. Fourteen years of meteorological parameters, aerosol variables (absorption and scattering coefficients, aerosol number concentration) and trace gases (CO, NOx, SO2) measured at the Jungfraujoch (JFJ, 3580 m a.s.l.) have been analyzed as a function of different synoptic weather types. The Schuepp synoptic weather type of the Alps (SYNALP) classification from the Alpine Weather Statistics (AWS) was used to define the synoptic meteorology over the whole Swiss region. The seasonal contribution of each synoptic weather type to the aerosol concentration was deduced from the aerosol annual cycles while the planetary boundary layer (PBL) influence was estimated by means of the diurnal cycles. Since aerosols are scavenged by precipitation, the diurnal cycle of the CO concentration was also used to identify polluted air masses. SO2 and NOx concentrations were used as precursor tracers for new particle formation and growth, respectively. The aerosol optical parameters and number concentration show elevated loadings during advective weather types during the December–March period and for the convective anticyclonic and convective indifferent weather types during the April–September period. This study confirms the consensus view that the JFJ is mainly influenced by the free troposphere during winter and by injection of air parcels from the PBL during summer. A more detailed picture is, however, drawn where the JFJ is completely influenced by free tropospheric air masses in winter during advective weather types and largely influenced by the PBL also during the night in summer during the subsidence weather type. Between these two extreme situations, the PBL influence at the JFJ depends on both the time of year and the synoptic weather type. The fraction of PBL air transported to the JFJ was estimated by the relative increase of the specific humidity and CO.