A European aerosol phenomenology-5: Climatology of black carbon optical properties at 9 regional background sites across Europe
| العنوان: | A European aerosol phenomenology-5: Climatology of black carbon optical properties at 9 regional background sites across Europe |
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| المؤلفون: | Andrés Alastuey, Karl Espen Yttri, Ernest Weingartner, Nikos Mihalopoulos, David C. S. Beddows, Hans Areskoug, Roy M. Harrison, Thomas Müller, Paolo Laj, Marco Zanatta, Marco Pandolfi, Jean-Luc Jaffrezo, Fabrizia Cavalli, Nicolas Bukowiecki, Martin Gysel, Erik Swietlicki, Gerald Spindler, Giorgos Kouvarakis, Karine Sellegri, Markus Fiebig, Urs Baltensperger, J. P. Putaud, Alfred Wiedensohler |
| المساهمون: | Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de météorologie physique (LaMP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Commission, European Research Council, Alastuey, Andrés, Pandolfi, Marco, Department of Physics, INAR Physics, Alastuey, Andrés [0000-0002-5453-5495], Pandolfi, Marco [0000-0002-7493-7213] |
| المصدر: | Atmospheric Environment Atmospheric Environment, 2016, 145, pp.346-364. ⟨10.1016/j.atmosenv.2016.09.035⟩ Digital.CSIC. Repositorio Institucional del CSIC instname |
| بيانات النشر: | Elsevier BV, 2016. |
| سنة النشر: | 2016 |
| مصطلحات موضوعية: | Mediterranean climate, Atmospheric Science, 010504 meteorology & atmospheric sciences, AIR-QUALITY, Radiative forcing, VISIBLE-LIGHT ABSORPTION, Photometer, ACTRIS, Ebas, 010501 environmental sciences, Thermal optical analysis, 114 Physical sciences, 01 natural sciences, WESTERN MEDITERRANEAN BASIN, Black carbon, ORGANIC-CARBON, PARTICULATE MATTER, Environmental Science(all), medicine, Geometric standard deviation, Light absorption, 1172 Environmental sciences, 0105 earth and related environmental sciences, General Environmental Science, Total organic carbon, MAC, MIXING STATE, Atmosphere, Mass absorption cross-section, Particulates, Seasonality, medicine.disease, Aerosol, Europe, [SDU]Sciences of the Universe [physics], 13. Climate action, FILTER-BASED MEASUREMENTS, Climatology, Environmental science, Spatial variability, Elemental carbon, CROSS-SECTION, BROWN CARBON |
| الوصف: | A reliable assessment of the optical properties of atmospheric black carbon is of crucial importance for an accurate estimation of radiative forcing. In this study we investigated the spatio-temporal variability of the mass absorption cross-section (MAC) of atmospheric black carbon, defined as light absorption coefficient (σap) divided by elemental carbon mass concentration (mEC). σap and mEC have been monitored at supersites of the ACTRIS network for a minimum period of one year. The 9 rural background sites considered in this study cover southern Scandinavia, central Europe and the Mediterranean. σap was determined using filter based absorption photometers and mEC using a thermal-optical technique. Homogeneity of the data-set was ensured by harmonization of all involved methods and instruments during extensive intercomparison exercises at the European Center for Aerosol Calibration (ECAC). Annual mean values of σap at a wavelength of 637 nm vary between 0.66 and 1.3 Mm−1 in southern Scandinavia, 3.7–11 Mm−1 in Central Europe and the British Isles, and 2.3–2.8 Mm−1 in the Mediterranean. Annual mean values of mEC vary between 0.084 and 0.23 μg m−3 in southern Scandinavia, 0.28–1.1 in Central Europe and the British Isles, and 0.22–0.26 in the Mediterranean. Both σap and mEC in southern Scandinavia and Central Europe have a distinct seasonality with maxima during the cold season and minima during summer, whereas at the Mediterranean sites an opposite trend was observed. Annual mean MAC values were quite similar across all sites and the seasonal variability was small at most sites. Consequently, a MAC value of 10.0 m2 g−1 (geometric standard deviation = 1.33) at a wavelength of 637 nm can be considered to be representative of the mixed boundary layer at European background sites, where BC is expected to be internally mixed to a large extent. The observed spatial variability is rather small compared to the variability of values in previous literature, indicating that the harmonization efforts resulted in substantially increased precision of the reported MAC. However, absolute uncertainties of the reported MAC values remain as high as ± 30–70% due to the lack of appropriate reference methods and calibration materials. The mass ratio between elemental carbon and non-light-absorbing matter was used as a proxy for the thickness of coatings around the BC cores, in order to assess the influence of the mixing state on the MAC of BC. Indeed, the MAC was found to increase with increasing values of the coating thickness proxy. This provides evidence that coatings do increase the MAC of atmospheric BC to some extent, which is commonly referred to as lensing effect. © 2016 The Authors The research leading to these results has received funding from the European Union Seventh Framework Programme (ACTRIS, FP7/2007-2013, grant agreement no. 262254 ). ACTRIS-2 is a European Project supported by the European Commission Horizon 2020 Research and Innovation Framework Programme (ACTRIS-2, H2020-INFRAIA-2014-2015, grant agreement no. 654109 ). This work was also supported by grants from Labex OSUG@2020 (PhD investissements d'avenir – ANR10 LABX56) and from the European Research Council (ERC-CoG 615922-BLACARAT). Appendix A. |
| تدمد: | 1352-2310 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7d8b1c538469c220130f5f04c4e25e23 https://doi.org/10.1016/j.atmosenv.2016.09.035 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....7d8b1c538469c220130f5f04c4e25e23 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13522310 |
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