scholarly journals Highly time resolved chemical characterization of submicron organic aerosols at a polluted urban location

2016 ◽  
Vol 18 (10) ◽  
pp. 1285-1296 ◽  
Author(s):  
Bharath Kumar ◽  
Abhishek Chakraborty ◽  
S. N. Tripathi ◽  
Deepika Bhattu
Keyword(s):  
Real Time ◽  
Black Carbon ◽  
Organic Aerosols ◽  
Chemical Characterization ◽  
Winter Period ◽  
Late Winter ◽  
Time Resolved ◽  
Urban Location

Real time concentrations of non-refractory submicron (NR-PM1) aerosols and Black Carbon (BC) were measured during the late winter period (February–March) in a polluted urban location (Kanpur) of India.

Time-resolved chemical characterization of aerosol particles down to 6 nm diameter in Stockton, California

2013 ◽  
Author(s):  
Arantza Eiguren-Fernandez ◽  
Gregory Lewis ◽  
Steven Spielman ◽  
Susanne Hering
Keyword(s):  
Aerosol Particles ◽  
Chemical Characterization ◽  
Time Resolved

scholarly journals Measurement report: Effects of photochemical aging on the formation and evolution of summertime secondary aerosol in Beijing

2020 ◽  
Author(s):  
Tianzeng Chen ◽  
Jun Liu ◽  
Qingxin Ma ◽  
Biwu Chu ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Exposure Dose ◽  
Time Resolved ◽  
Increase Rate ◽  
Key Factor ◽  
Formation And Evolution ◽  
Photochemical Aging ◽  
Observation Period

Abstract. Atmospheric submicron aerosols have a great effect on air quality and human health, while their formation and evolution processes are still not fully understood. Herein, the crucial role of atmospheric oxidation capacity, as characterized by OH exposure dose in the formation and evolution of secondary submicron aerosols, was systematically investigated based on a highly time-resolved chemical characterization of PM1 in a southern suburb of Beijing in summertime from 25th July to 21st August 2019. The averaged concentration of PM1 was 19.3 ± 11.3 μg m−3, and nearly half (48.3 %) of the mass was organic aerosols (OA) during the observation period. The equivalent photochemical age (ta) estimated from the ratios of toluene to benzene was applied to characterize the OH exposure dose of the air mass. The relationships of NR–PM1 species, OA factors (i.e., one hydrocarbon-like (HOA) and three oxygenated (LO-OOA, SV-OOA and MO-OOA) organic aerosol factors) and elemental compositions (e.g., H / C, O / C, N / C, S / C, OM / OC, and OSc) to ta were analyzed in detail. It was found that higher PM1 concentration accompanied longer ta, with an average increase rate of 0.8 μg m−3 per hour. Meanwhile, the formation of SO42− and MO-OOA were most sensitive to the increase in ta, and their contributions to PM1 were enhanced from 19 % to 27 % and from 27 % to 48 %, respectively, as ta increased from 9.4 h to 19.6 h. In addition, OSc and the ratios of O / C and OM / OC increased with the increase in ta. These results indicated that photochemical aging is a key factor leading to the evolution of OA and the increase of PM1 in summertime.

scholarly journals Chemical characterization of submicron regional background aerosols in the Western Mediterranean using an Aerosol Chemical Speciation Monitor

2015 ◽  
Vol 15 (1) ◽  
pp. 965-1000 ◽  
Author(s):  
M. C. Minguillón ◽  
A. Ripoll ◽  
N. Pérez ◽  
A. S. H. Prévôt ◽  
F. Canonaco ◽  
...  
Keyword(s):  
Real Time ◽  
Chemical Speciation ◽  
Chemical Characterization ◽  
Western Mediterranean ◽  
Data Matrix ◽  
Mass Spectral ◽  
Submicron Aerosol ◽  
Regional Background ◽  
Multilinear Engine

Abstract. An Aerosol Chemical Speciation Monitor (ACSM, Aerodyne Research Inc.) was deployed at Montseny (MSY, 720 m a.s.l.) regional background site in the Western Mediterranean from June 2012 to July 2013 to measure real-time inorganic (nitrate, sulphate, ammonium and chloride) and organic submicron aerosol concentrations. Co-located measurements were also carried out including real-time submicron particulate matter (PM1) and black carbon (BC) concentrations, and off-line PM1 chemical analysis. This is one of the few studies that compare ACSM data with off-line PM1 measurements, avoiding the tail of the coarse mode included in the PM2.5 fraction. The ACSM + BC concentrations agreed with the PM1 measurements, and strong correlation was found between the concentrations of ACSM species and the off-line measurements, although some discrepancies remain unexplained. Results point to a current underestimation of the relative ionization efficiency (RIE) established for organic aerosol (OA), which should be revised in the future. The OA was the major component of submicron aerosol (53% of PM1), with a higher contribution in summer (58% of PM1) than in winter (45% of PM1). Source apportionment of OA was carried out by applying Positive Matrix Factorization (PMF) using the Multilinear Engine (ME-2) to the organic mass spectral data matrix. Three sources were identified in summer: hydrocarbon-like OA (HOA), low-volatile oxygenated OA (LV-OOA), and semi-volatile oxygenated OA (SV-OOA). The secondary OA (SOA, 4.7 μg m−3, sum of LV-OOA and SV-OOA) accounted for 85% of the total OA and its formation during daytime (mainly SV-OOA) was estimated to be 1.1 μg m−3. In winter, HOA was also identified (12% of OA), a contribution from biomass burning OA was included, and it was not possible to differentiate two different SOA factors but a single OOA factor was resolved. The OOA contribution represented the 60% of the total OA, with a degree of oxidation higher than both OOA summer factors. An intense wildfire episode was studied obtaining a region-specific BBOA profile.

RECENT EXPERIENCE FROM MULTIPLE REMOTE SENSING AND MONITORING TO IMPROVE OIL SPILL RESPONSE OPERATIONS

2008 ◽  
Vol 2008 (1) ◽  
pp. 407-412 ◽  
Author(s):  
Hans V. Jensen ◽  
Jørn H. S. Andersen ◽  
Per S. Daling ◽  
Elisabeth Nøst
Keyword(s):  
Remote Sensing ◽  
Real Time ◽  
Oil Spill ◽  
Chemical Characterization ◽  
Ground Truth ◽  
Lessons Learned ◽  
Recent Experience ◽  
Aerial Surveillance ◽  
Wide Range

ABSTRACT Introducing regular aerial surveillance in 1981 and near-real time radar satellite detection services in 1992, Norway has obtained a substantial experience in multi sensor oil spill remote sensing. Since 2001 NOFO has been a driving force in the development and utilization of ship-based sensors for short to medium range oil spill detection, supplementing airborne and satellite remote sensing. During the NOFO Oil On Water Exercise in 2006 two satellites, four aircraft, one helicopter and two ships carrying wide range of sensors provided a unique opportunity to assess and compare remote sensing field data synchronized with ground-truth sampling from three sampling MOB-boats. The sampling boats were equipped for doing oil slick thickness measurements and physical-chemical characterization of the surface oil properties. A new vessel-based dispersant application system was field tested executing dispersant treatment of two oil slicks while supported by live infrared video transmitted to the vessel from helicopter. The success of this experiment was documented by extensive monitoring and characterization of the surface oil and the dispersed oil plume during and after the dispersant treatment. This guiding technique, in using aerial forward looking IR-video live transmission from helicopter and remote sensing aircraft, has been practiced later during a recent accidental oil spill on the Norwegian continental shelf. To utilize multiple remote sensors operationally from a response vessel, it is necessary to compare signatures from different sensors in near real time. This paper describes core elements of the remote sensing and ground-truth monitoring during oil on water exercises in recent years, lessons learned and how NOFO will continue developing remote sensing operations related to oil spill combating in reduced visibility and light conditions.

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