 |
| Titel |
Characteristics of size distributions at urban and rural locations in New York |
| VerfasserIn |
M.-S. Bae, J. J. Schwab, O. Hogrefe, B. P. Frank, G. G. Lala, K. L. Demerjian |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 10 ; Nr. 10, no. 10 (2010-05-18), S.4521-4535 |
| Datensatznummer |
250008459
|
| Publikation (Nr.) |
 copernicus.org/acp-10-4521-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
Paired nano- and long-tube Scanning Mobility Particle Sizer (SMPS) systems
were operated for four different intensive field campaigns in New York
State. Two of these campaigns were at Queens College in New York City,
during the summer of 2001 and the winter of 2004. The other field campaigns
were at rural sites in New York State.
The data with the computed diffusion loss corrections for the sampling lines
and the SMPS instruments were examined and the combined SMPS data sets for
each campaign were obtained. The diffusion corrections significantly affect
total number concentrations, and in New York City, affect the mode structure
of the size distributions. The relationship between merged and integrated
SMPS total number concentrations with the diffusion loss corrections and the
CPC number concentrations yield statistically significant increases (closer
to 1) in the slope and correlation coefficient compared to the uncorrected
values. The measurements are compared to PM2.5 mass concentrations and
ion balance indications of aerosol acidity. Analysis of particle growth rate
in comparison to other observations can classify the events and illustrate
that urban and rural new particle formation and growth are the result of
different causes. Periods of low observed PM2.5 mass, high number
concentration, and low median diameter due to small fresh particles are
associated with primary emissions for the urban sites; and with particle
nucleation and growth for the rural sites. The observations of high
PM2.5 mass, lower number concentrations, and higher median diameter are
mainly due to an enhancement of photochemical reactions leading to
condensation processes in relatively aged air. There are statistically
different values for the condensation sink (CS) between urban and rural
areas. While there is good association (r2>0.5) between the
condensation sink (CS) in the range of 8.35–283.9 nm and PM2.5 mass
in the urban areas, there is no discernable association in the rural areas.
The average values computed for the CS lie in the range
8.7×10−3–3.5×10−2 s−1. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|