Impact of North America on the aerosol composition in the North Atlantic free troposphere
-
Published:2017-06-20
Issue:12
Volume:17
Page:7387-7404
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
García M. Isabel, Rodríguez SergioORCID, Alastuey AndrésORCID
Abstract
Abstract. In the AEROATLAN project we study the composition of aerosols collected over ∼ 5 years at Izaña Observatory (located at ∼ 2400 m a.s.l. in Tenerife, the Canary Islands) under the prevailing westerly airflows typical of the North Atlantic free troposphere at subtropical latitudes and midlatitudes. Mass concentrations of sub-10 µm aerosols (PM10) carried by westerly winds to Izaña, after transatlantic transport, are typically within the range 1.2 and 4.2 µg m−3 (20th and 80th percentiles). The main contributors to background levels of aerosols (PM10 within the 1st–50th percentiles = 0.15–2.54 µg m−3) are North American dust (53 %), non-sea-salt sulfate (14 %) and organic matter (18 %). High PM10 events (75th–95th percentiles ≈ 4.0–9.0 µg m−3) are prompted by dust (56 %), organic matter (24 %) and non-sea-salt sulfate (9 %). These aerosol components experience a seasonal evolution explained by (i) their spatial distribution in North America and (ii) the seasonal shift of the North American outflow, which migrates from low latitudes in winter (∼ 32° N, January–March) to high latitudes in summer (∼ 52° N, August–September). The westerlies carry maximum loads of non-sea-salt sulfate, ammonium and organic matter in spring (March–May), of North American dust from midwinter to mid-spring (February–May) and of elemental carbon in summer (August–September). Our results suggest that a significant fraction of organic aerosols may be linked to sources other than combustion (e.g. biogenic); further studies are necessary for this topic. The present study suggests that long-term evolution of the aerosol composition in the North Atlantic free troposphere will be influenced by air quality policies and the use of soils (potential dust emitter) in North America.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference68 articles.
1. Ancellet, G., Pelon, J., Totems, J., Chazette, P., Bazureau, A., Sicard, M., Di Iorio, T., Dulac, F., and Mallet, M.: Long-range transport and mixing of aerosol sources during the 2013 North American biomass burning episode: analysis of multiple lidar observations in the western Mediterranean basin, Atmos. Chem. Phys., 16, 4725–4742, https://doi.org/10.5194/acp-16-4725-2016, 2016. 2. Basart, S., Pérez, C., Nickovic, S., Cuevas, E., Schulz, M., and Baldasano, J. M.: Development and evaluation of BSC-DREAM8b dust regional model over Northern Africa, the Mediterranean and the Middle East regions, Tellus B, 64, 18539, https://doi.org/10.3402/tellusb.v64i0.18539, 2012. 3. Blanchard, C. L., Hidy, G. M., Shaw, S., Baumann, K., and Edgerton, E. S.: Effects of emission reductions on organic aerosol in the southeastern United States, Atmos. Chem. Phys., 16, 215–238, https://doi.org/10.5194/acp-16-215-2016, 2016. 4. Bonsang, B., Nguyen, B. C., Gaudry, A., and Lambert, G.: Sulfate enrichment in marine aerosols owing to biogenic gaseous sulfur compounds, J. Geophys. Res.-Oceans, 85, 7410–7416, https://doi.org/10.1029/JC085iC12p07410, 1980. 5. Cavalli, F., Viana, M., Yttri, K. E., Genberg, J., and Putaud, J.-P.: Toward a standardised thermal-optical protocol for measuring atmospheric organic and elemental carbon: the EUSAAR protocol, Atmos. Meas. Tech., 3, 79–89, https://doi.org/10.5194/amt-3-79-2010, 2010.
Cited by
21 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|