Title: Long-term Measurements of Submicrometer Aerosol Chemistry at the Southern Great Plains (SGP) Using an Aerosol Chemical Speciation Monitor (ACSM)

Abstract

In this study the long-term trends of non-refractory submicrometer aerosol (NR-PM1) composition and mass concentration measured by an Aerosol Chemical Speciation Monitor (ACSM) at the U.S. Department of Energy’s Southern Great Plains (SGP) site are discussed. Over the period of 19 months (Nov. 20, 2010 – June 2012) highly time resolved (~30 min.) NR-PM1 data was recorded. Using this dataset the value-added product (VAP) of deriving organic aerosol components (OACOMP) is introduced. With this VAP, multivariate analysis of the measured organic mass spectral matrix can be performed on long term data to return organic aerosol (OA) factors that are associated with distinct sources, evolution processes, and physiochemical properties. Three factors were obtained from this VAP including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a biomass burning OA (BBOA) factor. Back trajectory analyses were performed to investigate possible sources of major NR-PM1 species at the SGP site. Organics dominated NR-PM1 mass concentration for the majority of the study with the exception of winter, when nitrate increased due to transport of precursor species from surrounding urban and agricultural areas and also due to cooler temperatures. Sulfate mass concentrations showed little seasonal variation with mixed regional and local sources.more » In the spring BBOA emissions increased and were mainly associated with local fires. Isoprene and carbon monoxide emission rates were computed by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) to represent the spatial distribution of biogenic and anthropogenic sources, respectively. From this model there is evidence to support that biogenic emissions from the southeast contribute to SOA formation at the SGP site during the summer.« less

Authors:

Parworth, Caroline; Fast, Jerome D.; Mei, Fan; Shippert, Timothy R.; Sivaraman, Chitra; Tilp, Alison; Watson, Thomas; Zhang, Qi

Publication Date:

Wed Apr 01 00:00:00 EDT 2015

Research Org.:

Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1184946

Report Number(s):

PNNL-SA-106218
KP1704010

DOE Contract Number:  

AC05-76RL01830

Resource Type:

Journal Article

Journal Name:

Atmospheric Environment, 106:43-55

Additional Journal Information:

Journal Name: Atmospheric Environment, 106:43-55

Country of Publication:

United States

Language:

English

Subject:

Aerodyne aerosol mass spectrometer (AMS); Rural; Organic aerosols; Back-trajectory analysis; Biomass burning