A study of O3 and NO2 vertical structure in a coastal wooded zone near a metropolitan area, by means of DOAS measurements

Premuda, Margherita; Petritoli, A.; Masieri, Samuele; Palazzi, Elisa; Kostadinov, I.; Bortoli, Daniele; Ravegnani, F.; Giovanelli, G.

doi:10.1016/j.atmosenv.2013.01.050

Cited by 4 publications

(3 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several previous studies used DOAS to measure tropospheric air pollution [ 16 – 21 ]. Premuda [ 22 ] analyzed the vertical structure of O 3 and NO 2 concentrations measured by DOAS on the Castel Porziano Presidential Estate pine forest near a metropolitan area. Observation for SO 2 , NO 2, and O 3 concentrations by the DOAS technique in an urban semi-industrial area of Athens, Greece, provided the evidence of higher ozone concentrations during weekends despite lower concentrations of ozone precursors [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

Zhao

Wang

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations.

show abstract

Section: Introductionmentioning

confidence: 99%

Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

Zhao

Wang

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…NOX emission flux errors mainly come from the VCD, wind speed, wind direction, car moving vector, NOX/NO2 ratio, and lifetime measurement errors or uncertainty [27][28][29][30][31][32]. The NOX emission flux is obtained with: (15) where ∆F RNOx represents the NOX flux error introduced by the NOX/NO2 ratio uncertainty. The NOX/NO2 ratio uncertainty we assumed to be about ± 0.1.…”

Section: Nox Emission Flux Error Sourcesmentioning

confidence: 99%

“…The large spatial scales of these cities and the predominance of moving sources make Differential optical absorption spectroscopy (DOAS) is a remote sensing technique developed in the 1970s and used for measuring atmospheric gases [11,12]. The DOAS technique is widely applied to measure trace gases [13][14][15]. An important application of the DOAS method is to measure the gas emission flux, such as NOx and SO 2 , using the close integral method (for area emitters) and the flow rate method (for point sources) [16,17].…”

Section: Introductionmentioning

confidence: 99%

NOx Emission Flux Measurements with Multiple Mobile-DOAS Instruments in Beijing

Huang

Xie

et al. 2020

Remote Sensing

View full text Add to dashboard Cite

NOX (NOX = NO + NO2) emissions measurements in Beijing are of great significance because they can aid in understanding how NOX pollution develops in mega-cities throughout China. However, NOX emissions in mega-cities are difficult to measure due to changes in wind patterns and moving sources on roads during measurement. To obtain good spatial coverage on different ring roads in Beijing over a short amount of time, two mobile differential optical absorption spectroscopy (DOAS) instruments were used to measure NOX emission flux from April 18th to 26th, 2018. In addition, a wind profile radar provided simultaneous wind field measurements for altitudes between 50 m and 1 km for each ring road measurement. We first determined NOX emission flux of different ring roads using wind field averages from measured wind data. The results showed that the NOX emission flux of Beijing’s fifth ring road, which represented the urban part, varied from (19.29 ± 5.26) × 1024 molec./s to (36.46 ± 12.86) × 1024 molec./s. On April 20th, NOX emission flux for the third ring was slightly higher than the fourth ring because the two ring roads were measured at different time periods. We then analyzed the NOX emission flux error budget and error sensitivity. The main error source was the wind field uncertainty. For some measurements, the main emission flux error source was either wind speed uncertainty or wind direction uncertainty, but not both. As Beijing’s NOX emissions came from road vehicle exhaust, we found that emission flux error had a more diverse sensitivity to wind direction uncertainty, which improved our knowledge on this topic. The NOX emission flux error sensitivity study indicated that more accurate measurements of the wind field are crucial for effective NOX emission flux measurements in Chinese mega-cities. Obtaining actual time and high resolved wind measurements is an advantage for mega-cities’ NOX emission flux measurements. The emission flux errors caused by wind direction and wind speed uncertainties were clearly distinguished. Other sensitivity studies indicated that NOX/NO2 ratio uncertainty dominated flux errors when the NOX/NO2 ratio uncertainty was >0.4. Using two mobile-DOAS and wind profile radars to measure NOx emission flux improved the quality of the emission flux measuring results. This approach could be applied to many other mega-cities in China and in others countries.

show abstract

Vertical Distribution of Lower Tropospheric <inline-formula> <tex-math notation="TeX">$\hbox{NO}_{2}$</tex-math></inline-formula> Derived From Diffuse Solar Radiation Measurements: A Geometrical Retrieval Approach

Masieri

Palazzi

Ravegnani

et al. 2014

IEEE Trans. Geosci. Remote Sensing

View full text Add to dashboard Cite

A study of O3 and NO2 vertical structure in a coastal wooded zone near a metropolitan area, by means of DOAS measurements

Cited by 4 publications

References 30 publications

Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

NOx Emission Flux Measurements with Multiple Mobile-DOAS Instruments in Beijing

Vertical Distribution of Lower Tropospheric <inline-formula> <tex-math notation="TeX">$\hbox{NO}_{2}$</tex-math></inline-formula> Derived From Diffuse Solar Radiation Measurements: A Geometrical Retrieval Approach

Contact Info

Product

Resources

About