气候变化领域集成服务门户(CCPortal): Transport of Po Valley aerosol pollution to the northwestern Alps-Part 1: Phenomenology

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DOI	10.5194/acp-19-3065-2019
	Transport of Po Valley aerosol pollution to the northwestern Alps-Part 1: Phenomenology
	Diémoz H.; Barnaba F.; Magri T.; Pession G.; Dionisi D.; Pittavino S.; Tombolato I.K.F.; Campanelli M.; Ceca L.S.D.; Hervo M.; Di Liberto L.; Ferrero L.; Gobbi G.P.
发表日期	2019
ISSN	16807316
起始页码	3065
结束页码	3095
卷号	19 期号:5
英文摘要	Mountainous regions are often considered pristine environments; however they can be affected by pollutants emitted in more populated and industrialised areas, transported by regional winds. Based on experimental evidence, further supported by modelling tools, here we demonstrate and quantify the impact of air masses transported from the Po Valley, a European atmospheric pollution hotspot, to the northwestern Alps. This is achieved through a detailed investigation of the phenomenology of near-range (a few hundred kilometres), trans-regional transport, exploiting synergies of multi-sensor observations mainly focussed on particulate matter. The explored dataset includes vertically resolved data from atmospheric profiling techniques (automated lidar ceilometers, ALCs), vertically integrated aerosol properties from ground (sun photometer) and space, and in situ measurements (PM10 and PM2.5, relevant chemical analyses, and aerosol size distribution). During the frequent advection episodes from the Po basin, all the physical quantities observed by the instrumental setup are found to significantly increase: the scattering ratio from ALC reaches values >30, aerosol optical depth (AOD) triples, surface PM10 reaches concentrations >100 μg mg-3 even in rural areas, and contributions to PM10 by secondary inorganic compounds such as nitrate, ammonium, and sulfate increase up to 28 %, 8 %, and 17 %, respectively. Results also indicate that the aerosol advected from the Po Valley is hygroscopic, smaller in size, and less light-absorbing compared to the aerosol type locally emitted in the northwestern Italian Alps. In this work, the phenomenon is exemplified through detailed analysis and discussion of three case studies, selected for their clarity and relevance within the wider dataset, the latter being fully exploited in a companion paper quantifying the impact of this phenomenology over the long-term cit id 1(Diémoz et al.a href 51 2019). For the three case studies investigated, a high-resolution numerical weather prediction model (COSMO) and a Lagrangian tool (LAGRANTO) are employed to understand the meteorological mechanisms favouring transport and to demonstrate the Po Valley origin of the air masses. In addition, a chemical transport model (FARM) is used to further support the observations and to partition the contributions of local and non-local sources. Results show that the simulations are important to the understanding of the phenomenon under investigation. However, in quantitative terms, modelled PM10 concentrations are 4-5 times lower than the ones retrieved from the ALC and maxima are anticipated in time by 6-7 h. Underestimated concentrations are likely mainly due to deficiencies in the emission inventory and to water uptake of the advected particles not fully reproduced by FARM, while timing mismatches are likely an effect of suboptimal simulation of up-valley and down-valley winds by COSMO. The advected aerosol is shown to remarkably degrade the air quality of the Alpine region, with potential negative effects page3066 on human health, climate, and ecosystems, as well as on the touristic development of the investigated area. The findings of the present study could also help design mitigation strategies at the trans-regional scale in the Po basin and suggest an observation-based approach to evaluate the outcome of their implementation. © 2019 Author(s).
语种	英语
scopus关键词	aerosol; air mass; atmospheric pollution; data set; in situ measurement; mountain region; particulate matter; pollutant transport; Alps; Italy; Po Valley
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144583
作者单位	ARPA Valle d'Aosta, Saint-Christophe, Italy; Institute of Atmospheric Science and Climate, ISAC-CNR, Rome, Italy; Instituto de Física Rosario, Rosario, Argentina; MeteoSwiss, Payerne, Switzerland; GEMMA and POLARIS Research Centres, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Milan, Italy
推荐引用方式 GB/T 7714	Diémoz H.,Barnaba F.,Magri T.,et al. Transport of Po Valley aerosol pollution to the northwestern Alps-Part 1: Phenomenology[J],2019,19(5).
APA	Diémoz H..,Barnaba F..,Magri T..,Pession G..,Dionisi D..,...&Gobbi G.P..(2019).Transport of Po Valley aerosol pollution to the northwestern Alps-Part 1: Phenomenology.Atmospheric Chemistry and Physics,19(5).
MLA	Diémoz H.,et al."Transport of Po Valley aerosol pollution to the northwestern Alps-Part 1: Phenomenology".Atmospheric Chemistry and Physics 19.5(2019).