کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5753066 1620307 2017 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nitrous acid in a street canyon environment: Sources and contributions to local oxidation capacity
ترجمه فارسی عنوان
اسید نیتریک در یک محیط کانوی خیابان: منابع و کمک به ظرفیت اکسیداسیون محلی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
چکیده انگلیسی
Nitrous acid (HONO) plays an important role in radical formation and photochemical oxidation processes in the boundary layer. However, its impact on the chemistry in a street canyon microenvironment has not been thoroughly investigated. In this study, we measured HONO in a street canyon in urban Hong Kong and used an observation-based box model (OBM) with the Master Chemical Mechanism (MCM v3.3.1) to investigate the contribution of HONO to local oxidation chemistry. The observed HONO mixing ratios were in the range of 0.4-13.9 ppbv, with an average of 3.91 ppbv in the daytime and 2.86 ppbv at night. A mean HONO/NOx emission ratio of 1.0% (±0.5%) from vehicle traffic was derived. OBM simulations constrained by the observed HONO showed that the maximum concentrations of OH, HO2, and RO2 reached 4.65 × 106, 4.40 × 106, and 1.83 × 106 molecules cm−3, which were 7.9, 5.0, and 7.5 times, respectively, the results in the case without HONO constrained. Photolysis of HONO contributed to 86.5% of the total primary radical production rates and led to efficient NO2 and O3 production under the condition of weak regional transport of O3. The formation of HNO3 contributed to 98.4% of the total radical termination rates. Our results suggest that HONO could significantly increase the atmospheric oxidation capacity in a street canyon and enhance the secondary formation of HNO3 and HCHO, which can damage outdoor building materials and pose health risks to pedestrians.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 167, October 2017, Pages 223-234
نویسندگان
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