In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 11 ( 2018-06-06), p. 7933-7950
Abstract:
Abstract. Amines have received increasing attention in recent years because of
their potential role in new particle formation in the atmosphere and
their impact on aerosol chemistry. High concentrations of amines are
expected to be limited to the vicinity of source regions due to
their short lifetime, highlighting the necessity of having a better
understanding of contributions of emissions from different source
types. This study presents the first high-resolution model
simulation of concentrations of methylamines on a regional scale
over the Yangtze River Delta region in East China. The WRF-Chem with
nested grids is used in model simulations. In contrast to the very
limited existing modeling studies that assumed a fixed ratio (FR) of
amines to total ammonia emission, we derive source-dependent ratios
(SDR) that distinguish C1-amine (CH3NH2), C2-amines
(C2H7N), C3-amines (C3H9N) emissions from five
different source types (agriculture, residential, transportation,
chemical industry, and other industry). The amines-to-ammonia mass
emission ratios, estimated from previous measurements, are 0.026,
0.0015, 0.0011, 0.0011, and 0.0011 for C1-amine; 0.007, 0.0018,
0.0015, 0.01, and 0.0009 for C2-amines; and 0.0004, 0.0005, 0.00043,
0.0006, and 0.0004 for C3-amines for chemical–industrial, other
industrial, agricultural, residential, and transportational sources,
respectively. The simulated concentrations of C1-, C2-, and
C3-amines, based on both FR and SDR, have been compared with field
measurements at a suburban site in Nanjing and at an urban site in
Shanghai, China. SDR substantially improves the ability of the model
in capturing the observed concentrations of
methylamines. Concentrations of C1-, C2-, and C3-amines in the
surface layer in the Yangtze River Delta region are generally in the
range of 2–20, 5–50, and 0.5–4 pptv. Vertically, the
concentrations of C1-, C2-, and C3-amines decrease quickly with
altitude, dropping by a factor of ∼10 from the surface to
∼900 hPa. Results from the present study are critical
to evaluating potential roles of amines in nucleation and chemical
processes in polluted air.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-7933-2018
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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