scholarly journals Quantifying the impact of the COVID-19 lockdown on air quality in downtown Toronto using open-path Fourier transform spectroscopy

2021 ◽  
Author(s):  
Yuan You ◽  
Brendan Byrne ◽  
Orfeo Colebatch ◽  
Dylan Jones ◽  
Jinwoong Kim ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Air Quality ◽  
Fourier Transform Spectroscopy ◽  
Open Path ◽  
The Impact

scholarly journals Quantifying the Impact of the COVID-19 Pandemic Restrictions on CO, CO2, and CH4 in Downtown Toronto Using Open-Path Fourier Transform Spectroscopy

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 848
Author(s):  
Yuan You ◽  
Brendan Byrne ◽  
Orfeo Colebatch ◽  
Richard L. Mittermeier ◽  
Felix Vogel ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Mole Fraction ◽  
Urban Areas ◽  
Trace Gas ◽  
Reference Period ◽  
Mean Values ◽  
Percentage Decrease ◽  
Open Path ◽  
The Impact ◽  
At Home

During the global COVID-19 pandemic, anthropogenic emissions of air pollutants and greenhouse gases (GHGs), especially traffic emissions in urban areas, have declined. Long-term measurements of trace gas concentrations in urban areas can be used to quantify the impact of emission reductions on GHG mole fractions. Open-path Fourier transform infrared (OP-FTIR) spectroscopy is a non-intrusive technique that can be used to simultaneously measure multiple atmospheric trace gases in the boundary layer. This study investigates the reduction of mole fractions and mole fraction enhancements above background for surface CO, CO2, and CH4 in downtown Toronto, Canada (the fourth largest city in North America) during the 2020 and 2021 COVID-19 stay-at-home periods. Mean values obtained from these periods were compared with mean values from a reference period prior to the 2020 restrictions. Mean CO mole fraction enhancement declined by 51 ± 23% and 42 ± 24% during the 2020 and 2021 stay-at-home periods, respectively. The mean afternoon CO2 mole fraction enhancement declined by 3.9 ± 2.6 ppm (36 ± 24%) and 3.5 ± 2.8 ppm (33 ± 26%) during the stay-at-home periods in 2020 and 2021. In contrast, CH4 mole fraction enhancement did not show any significant decrease. Diurnal variation in CO during the stay-at-home period in 2020 was also significantly reduced relative to the reference period in 2020. These reductions in trace gas mole fraction enhancements coincide with the decline of local traffic during the stay-at-home periods, with an estimated reduction in CO and CO2 enhancements of 0.74 ± 0.15 ppb and 0.18 ± 0.05 ppm per percentage decrease in traffic, respectively.

An X-ray diffractometer coupled with diffuse reflectance infrared Fourier transform spectroscopy and gas chromatography forin situandin operandocharacterization: an innovative analytical laboratory instrument

2012 ◽  
Vol 46 (1) ◽  
pp. 262-266 ◽  
Author(s):  
Laure Braconnier ◽  
Isabelle Clémençon ◽  
Christèle Legens ◽  
Virginie Moizan ◽  
Fabrice Diehl ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Diffuse Reflectance ◽  
Fourier Transform Spectroscopy ◽  
Material Surface ◽  
X Ray Diffraction ◽  
Reaction Cell ◽  
X Ray ◽  
High Pressure Reaction ◽  
Diffuse Reflectance Infrared ◽  
The Impact

In heterogeneous catalysis, chemical reactions take place at the surface of the material and can be influenced by its structure. To understand better the impact of the material surface and structure on catalytic properties, it is important to characterize them simultaneously. The association of X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy, combined in a single dedicated high-temperature and high-pressure reaction cell with an online gas chromatograph, could be the answer to this challenge. For the first time, such an analytical tool has been developed for laboratory applications. The use of this device is illustrated, and it is validated through thein situstudy of the thermal decomposition of calcium oxalate.

Open-path Fourier transform spectroscopy of gas emissions from Oldoinyo Lengai volcano, Tanzania

2002 ◽  
Vol 37 (2-3) ◽  
pp. 203-214 ◽  
Author(s):  
Clive Oppenheimer ◽  
Mike R. Burton ◽  
Jacques Durieux ◽  
David M. Pyle
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Spectroscopy ◽  
Oldoinyo Lengai ◽  
Gas Emissions ◽  
Open Path

Air Quality Monitoring by Open Path Fourier Transform Infrared (FTIR) Spectrometry

1997 ◽  
Author(s):  
Melissa D. Tucker ◽  
Rebecca C. Rowe ◽  
Ellen V. Miseo ◽  
James R. Valentine
Keyword(s):  
Fourier Transform ◽  
Air Quality ◽  
Fourier Transform Infrared ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Open Path ◽  
Ftir Spectrometry

Monitoring Urban Greenhouse Gases Using Open-Path Fourier Transform Spectroscopy

2020 ◽  
Vol 58 (1) ◽  
pp. 25-45 ◽  
Author(s):  
Brendan Byrne ◽  
Kimberly Strong ◽  
Orfeo Colebatch ◽  
Yuan You ◽  
Debra Wunch ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Greenhouse Gases ◽  
Fourier Transform Spectroscopy ◽  
Open Path

Noise and Finite Register Effects in Infrared Fourier Transform Spectroscopy

1976 ◽  
Vol 30 (5) ◽  
pp. 531-539 ◽  
Author(s):  
C. T. Foskett
Keyword(s):  
Fourier Transform ◽  
Data Acquisition ◽  
Fast Fourier Transform ◽  
Fourier Transform Spectroscopy ◽  
Noise Sources ◽  
Additional Noise ◽  
The Impact ◽  
The Relationship

Finite registers used in computations act as additional noise sources in infrared Fourier transform spectroscopy. The relationship between these noise sources and classical noise sources is examined. The impact of finite register lengths on data acquisition, computation of the fast Fourier transform (FFT), and post-FFT spectral manipulations leads to the conclusion that the minimum recommended register length is 27 bits.

scholarly journals The impact of measures to reduce ambient air PM<sub>10</sub> concentrations originating from road dust, evaluated for a street canyon in Helsinki

2019 ◽  
Vol 19 (17) ◽  
pp. 11199-11212 ◽  
Author(s):  
Ana Stojiljkovic ◽  
Mari Kauhaniemi ◽  
Jaakko Kukkonen ◽  
Kaarle Kupiainen ◽  
Ari Karppinen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Street Canyon ◽  
Dust Emission ◽  
Road Dust ◽  
Ambient Air ◽  
Air Quality Measurements ◽  
Emission Models ◽  
The Impact ◽  
Quality Measurements

Abstract. We have numerically evaluated how effective selected potential measures would be for reducing the impact of road dust on ambient air particulate matter (PM10). The selected measures included a reduction of the use of studded tyres on light-duty vehicles and a reduction of the use of salt or sand for traction control. We have evaluated these measures for a street canyon located in central Helsinki for four years (2007–2009 and 2014). Air quality measurements were conducted in the street canyon for two years, 2009 and 2014. Two road dust emission models, NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and FORE (Forecasting Of Road dust Emissions), were applied in combination with the Operational Street Pollution Model (OSPM), a street canyon dispersion model, to compute the street increments of PM10 (i.e. the fraction of PM10 concentration originating from traffic emissions at the street level) within the street canyon. The predicted concentrations were compared with the air quality measurements. Both road dust emission models reproduced the seasonal variability of the PM10 concentrations fairly well but under-predicted the annual mean values. It was found that the largest reductions of concentrations could potentially be achieved by reducing the fraction of vehicles that use studded tyres. For instance, a 30 % decrease in the number of vehicles using studded tyres would result in an average decrease in the non-exhaust street increment of PM10 from 10 % to 22 %, depending on the model used and the year considered. Modelled contributions of traction sand and salt to the annual mean non-exhaust street increment of PM10 ranged from 4 % to 20 % for the traction sand and from 0.1 % to 4 % for the traction salt. The results presented here can be used to support the development of optimal strategies for reducing high springtime particulate matter concentrations originating from road dust.

Sign in / Sign up

Export Citation Format

Share Document