TY - JOUR
T1 - Measurements of fog composition at a rural site
AU - Straub, Derek J.
AU - Hutchings, James W.
AU - Herckes, Pierre
N1 - Funding Information:
We are grateful to Youliang Wang, Aurelie Marcotte, Panjai Prapaipong, Andrea Clements, and Jessie Shipp for their help with sample analysis. We thank Jeff Collett for making the CHRCC and automated fog collection system available for our use. Funding was provided by National Science Foundation grant AGS0847710 .
PY - 2012/2
Y1 - 2012/2
N2 - Studies that focus on fog chemistry in the United States have been limited to relatively few locations. Apart from measurements along the East and West coasts and extensive analysis of radiation fog in the Central Valley of California, fog composition has been characterized in only a handful of other locations. To complement and expand the existing fog chemistry data that are currently available, a new field campaign was established at a rural location in Central Pennsylvania to produce a unique, long term record of fog composition. From 2007 to 2010, 41 fog events were sampled with an automated Caltech Heated Rod Cloudwater Collector (CHRCC). The collected samples were analyzed primarily for pH and major inorganic ions. Dissolved organic carbon (DOC) and trace metals were analyzed in selected samples and N-nitrosodimethylamine (NDMA) was quantified in two samples. Sample composition varied widely during the study period. Sulfate concentrations ranged from 15 to 955 (median-=-123) μN and pH varied between 3.08 and 7.41 (median-=-5.77). In terms of volume weighted averages, ammonium was the most abundant ionic species followed by sulfate, calcium, and nitrate. For the subset of samples in which DOC was analyzed, concentrations ranged from 2.2 to 22.6-mgC-l -1. Comparisons with regional precipitation chemistry measurements reveal the influence of local agricultural and soil sources on fog composition. The sum of sulfate, nitrate, and ammonium measured in the present study is considerably lower than the majority of radiation, precipitation, and coastal fogs collected in the United States although the ammonium/(nitrate-+-sulfate) ratio is similar to those found in the Central Valley of California.
AB - Studies that focus on fog chemistry in the United States have been limited to relatively few locations. Apart from measurements along the East and West coasts and extensive analysis of radiation fog in the Central Valley of California, fog composition has been characterized in only a handful of other locations. To complement and expand the existing fog chemistry data that are currently available, a new field campaign was established at a rural location in Central Pennsylvania to produce a unique, long term record of fog composition. From 2007 to 2010, 41 fog events were sampled with an automated Caltech Heated Rod Cloudwater Collector (CHRCC). The collected samples were analyzed primarily for pH and major inorganic ions. Dissolved organic carbon (DOC) and trace metals were analyzed in selected samples and N-nitrosodimethylamine (NDMA) was quantified in two samples. Sample composition varied widely during the study period. Sulfate concentrations ranged from 15 to 955 (median-=-123) μN and pH varied between 3.08 and 7.41 (median-=-5.77). In terms of volume weighted averages, ammonium was the most abundant ionic species followed by sulfate, calcium, and nitrate. For the subset of samples in which DOC was analyzed, concentrations ranged from 2.2 to 22.6-mgC-l -1. Comparisons with regional precipitation chemistry measurements reveal the influence of local agricultural and soil sources on fog composition. The sum of sulfate, nitrate, and ammonium measured in the present study is considerably lower than the majority of radiation, precipitation, and coastal fogs collected in the United States although the ammonium/(nitrate-+-sulfate) ratio is similar to those found in the Central Valley of California.
KW - Dissolved organic carbon
KW - Fog chemistry
KW - Inorganic ions
KW - Mid-Atlantic region
KW - Pennsylvania
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U2 - 10.1016/j.atmosenv.2011.11.014
DO - 10.1016/j.atmosenv.2011.11.014
M3 - Article
AN - SCOPUS:84155172805
SN - 1352-2310
VL - 47
SP - 195
EP - 205
JO - Atmospheric Environment
JF - Atmospheric Environment
ER -