Dissertation/Thesis Abstract

Characterization of Ambient Aerosols and Their Evolution under Various Atmospheric Conditions in the Northeast U.S. 
by Zhang, Jie, Ph.D., State University of New York at Albany, 2019, 288; 27669348
Abstract (Summary)

The University at Albany Atmospheric Sciences Research Center (ASRC) mobile laboratory, which includes a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS), a Scanning Mobility Particle Sizer (SMPS), and several gas sensors, etc., has been used to characterize atmospheric aerosols and air quality at different locations in the Northeastern US (including urban, forest, and mountain areas) and the aerosol evolutions under a variety of atmospheric conditions (including extreme weather, fog, and cloud, etc.). In this dissertation, I present the findings of the several field measurements using the ASRC mobile lab, focusing on the influences of extreme events (including high O3, heatwave, and firework displays) on urban aerosol properties, fog processing on rural forest formed secondary organic aerosol, and cloud processing of the mountain area aerosol.

For the urban area, we first investigated the influence of sea breeze on ozone and air quality using on-road measurements. Dramatic O3 spatial variations with a ∆O3 ∆y−1 in excess of 10 ppb km−1 were captured by the instruments, and high O3 and aerosol mass concentrations with high oxidation states were clearly influenced by the sea breeze plume. We also studied the aerosol evolution during an extreme heatwave period, and the results show two pollution patterns—one related directly to photo-oxidation of anthropogenic VOC and the other one related to further reaction through the oxidation of DMS throughout the ocean surface boundary layer. In a separate study, the impact of fireworks (FW) events on air quality was determined though measurements of aerosol particles from FW displays during the Independence Day (July 4, 2017) holiday period at Albany, NY, USA. The results showed the intense emission of FW particles from the Independence Day celebration (including K salt and FW related organics) contributed about 77% (36.3 μg m−3) of total PM1 (47.0 μg m−3) measured at the uptown site during Independence Day FW significantly influenced period (07/04 23:00-07/05 03:00). This highlights the significant episodic influence of FW burning on fine aerosol mass concentration and chemical characteristics while large numbers of people are clustered together and breathing the outdoor air.

Moving to the rural forested location, the effect of foggy conditions and fog processing on the characteristics of secondary aerosol was studied at Pinnacle State Park, NY. Our study identified two fresh biogenic secondary organic aerosol factors (BSOA: BSOA-1 and BSOA-2); BSOA-1 was likely formed through the reaction of biogenic volatile organic precursors with NO3 and converted to BSOA-2 through fragmentation or further oxidation. During fog processing, the more oxidized oxygenated organic aerosol (MO-OOA) showed the highest uptake into fog droplets, or scavenging efficiency (90%), followed by SO42− (50%), the less oxidized OOA (LO-OOA) (45%), and BSOA (BSOA-1+BSOA-2, 24%). The high positive correlation between relative humidity (RH)/or aerosol liquid water (ALW) and BSOA mass concentration suggests the importance of aqueous-phase processing on BSOA formation, and an increase in the ALW ratio of 0.1 corresponded to an average increase of about 0.2 μg m−3 in the BSOA factor.

Finally, a pilot study took place at Whiteface Mountain (WFM) in the Adirondacks of upstate NY during the summer of 2017 to evaluate the chemical processing of aerosol below and within clouds. Below-cloud and cloud interstitial submicron aerosols were characterized in real-time using the ASRC mobile lab. The observations also show chemical differences between the below-cloud layer, the transition layer (just below-cloud), and the in-cloud layer. The aerosol properties, such as mass concentration, size distribution, oxidation state and hygroscopicity parameter for each layer are discussed in detail.

Indexing (document details)
Advisor: Schwab, James
Commitee: Keesee, Robert, Min, Qilong, Lance, Sara
School: State University of New York at Albany
Department: Atmospheric and Environmental Sciences
School Location: United States -- New York
Source: DAI-B 81/7(E), Dissertation Abstracts International
Subjects: Atmospheric sciences, Atmospheric Chemistry
Keywords: Aerosol evolutions, Ambient aerosols, Firework, Fog and cloud, Heatwave, Sea breeze
Publication Number: 27669348
ISBN: 9781392558836
Copyright © 2020 ProQuest LLC. All rights reserved. Terms and Conditions Privacy Policy Cookie Policy