English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Secondary organic aerosol (SOA) in the southeastern US is investigated byanalyzing the spatial-temporal distribution of water-soluble organic carbon(WSOC) and other PM2.5 components from 900 archived 24-h Teflon filterscollected at 15 urban or rural EPA Federal Reference Method (FRM) networksites throughout 2007. Online measurements of WSOC at an urban/rural-pairedsite in Georgia in the summer of 2008 are contrasted to the filter data.Based on FRM filters, excluding biomass-burning events (levoglucosan< 50 ng m−3), WSOC and sulfate were highly correlated withPM2.5 mass (r2~0.7). Both components comprised a large massfraction of PM2.5 (13% and 31%, respectively, or~25% and 50% for WSOM and ammonium sulfate). Sulfate andWSOC both tracked ambient temperature throughout the year, suggesting thetemperature effects were mainly linked to faster photochemistry and/orsynoptic meteorology and less due to enhanced biogenic hydrocarbon emissions.FRM WSOC, and to a lesser extent sulfate, were spatially homogeneousthroughout the region, yet WSOC was moderately enhanced (27%) inlocations of greater predicted isoprene emissions in summer. A PositiveMatrix Factorization (PMF) analysis identified two major source types for thesummer WSOC; 22% of the WSOC were associated with ammonium sulfate, and56% of the WSOC were associated with brown carbon and oxalate. Asmall urban excess of FRM WSOC (10%) was observed in the summer of 2007,however, comparisons of online WSOC measurements at one urban/rural pair(Atlanta/Yorkville) in August 2008 showed substantially greater difference inWSOC (31%) relative to the FRM data, suggesting a low bias for urbanfilters. The measured Atlanta urban excess, combined with the estimatedboundary layer heights, gave an estimated Atlanta daily WSOC production ratein August of 0.55 mgC m−2 h−1 between mid-morning andmid-afternoon. This study characterizes the regional nature of fine particlesin the southeastern US, confirming the importance of SOA and the roles ofboth biogenic and anthropogenic emissions

atmospheric chemistry and physics

Spatial and seasonal variations of fine particle water-soluble organic carbon (WSOC) over the southeastern United States: implications for secondary organic aerosol formation