Title
Sea salt emission, transport and influence on size-segregated nitrate simulation: A case study in northwestern Europe by WRF-Chem
Author
Chen, Y.
Cheng, Y.
Ma, N.
Wolke, R.
Nordmann, S.
Schüttauf, S.
Ran, L.
Wehner, B.
Birmili, W.
van der Gon, H.A.C.D.
Mu, Q.
Barthel, S.
Spindler, G.
Stieger, B.
Müller, K.
Zheng, G.J.
Pöschl, U.
Su, H.
Wiedensohler, A.
Publication year
2016
Abstract
Sea salt aerosol (SSA) is one of the major components of primary aerosols and has significant impact on the formation of secondary inorganic particles mass on a global scale. In this study, the fully online coupled WRFChem model was utilized to evaluate the SSA emission scheme and its influence on the nitrate simulation in a case study in Europe during 10-20 September 2013. Meteorological conditions near the surface, wind pattern and thermal stratification structure were well reproduced by the model. Nonetheless, the coarse-mode (PM1-10) particle mass concentration was substantially overestimated due to the overestimation of SSA and nitrate. Compared to filter measurements at four EMEP stations (coastal stations: Bilthoven, Kollumerwaard and Vredepeel; inland station: Melpitz), the model overestimated SSA concentrations by a factor of 8-20. We found that this overestimation was mainly caused by overestimated SSA emissions over the North Sea during 16-20 September. Over the coastal regions, SSA was injected into the continental free troposphere through an "aloft bridge" (about 500 to 1000m above the ground), a result of the different thermodynamic properties and planetary boundary layer (PBL) structure between continental and marine regions. The injected SSA was further transported inland and mixed downward to the surface through downdraft and PBL turbulence. This process extended the influence of SSA to a larger downwind region, leading, for example, to an overestimation of SSA at Melpitz, Germany, by a factor of ∼20. As a result, the nitrate partitioning fraction (ratio between particulate nitrate and the summation of particulate nitrate and gas-phase nitric acid) increased by about 20%for the coarsemode nitrate due to the overestimation of SSA at Melpitz. However, no significant difference in the partitioning fraction for the fine-mode nitrate was found. About 140% overestimation of the coarse-mode nitrate resulted from the influence of SSA at Melpitz. In contrast, the overestimation of SSA inhibited the nitrate particle formation in the fine mode by about 20% because of the increased consumption of precursor by coarse-mode nitrate formation. © Author(s) 2016.
Subject
2015 Urban Mobility & Environment
CAS - Climate, Air and Sustainability
ELSS - Earth, Life and Social Sciences
Environment & Sustainability
Environment
Urbanisation
To reference this document use:
http://resolver.tudelft.nl/uuid:dc9454f4-c593-4e0d-8960-1ca8c44532a2
DOI
https://doi.org/10.5194/acp-16-12081-2016
TNO identifier
573068
Publisher
Copernicus GmbH
ISSN
1680-7316
Source
Atmospheric Chemistry and Physics, 16 (18), 12081-12097
Document type
article