 |
| Titel |
Different characteristics of new particle formation between urban and deciduous forest sites in Northern Japan during the summers of 2010–2011 |
| VerfasserIn |
J. Jung, Y. Miyazaki, K. Kawamura |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 1 ; Nr. 13, no. 1 (2013-01-04), S.51-68 |
| Datensatznummer |
250011715
|
| Publikation (Nr.) |
 copernicus.org/acp-13-51-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| To investigate new particle formation (NPF) events in urban and forest
environments, number size distributions of ultrafine particles were measured
at an urban site and a deciduous forest site in Sapporo, Northern Japan,
during the summers of 2011 and 2010, respectively. The burst of nucleation
mode particles at the urban site typically started in the morning
(07:00–11:30 local time, LT) with simultaneous increases in SO2 and
O3 concentrations and the UV index under clear (sunny) weather
conditions. The growth rates of nucleated particles at the urban site ranged
from 5.0 to 7.8 nm h−1 with an average of
6.3 ± 1.1 nm h−1. NPF events at the urban site were separated
into events with or without subsequent particle growth after the burst of
nucleation mode particles. This division was found to relate to prevailing
wind direction because the subsequent growth of freshly nucleated particles
typically occurred when wind direction shifted to northwesterly (from
residential and public park areas), whereas it did not occur under
southeasterly winds (from the downtown area). During the periods with NPF
events, elevated concentrations of non-methane hydrocarbons (NMHC) were
obtained under conditions of northwesterly winds when compared to
southeasterly winds, whereas no difference in SO2 levels was recorded.
These results suggest that variations in NMHC concentration may play an
important role in the growth of freshly nucleated particles at the urban
site. The burst of nucleation mode particles at the forest site typically
started around noon (10:30–14:30 LT), which was 3–4 h later than that at
the urban site. Interestingly, at the forest site the burst of nucleation
mode particles usually started when air masses originating from urban Sapporo
arrived at the forest site. The present study indicates that the inflow of
these urban air masses acted as a trigger for the initiation of the burst of
nucleation mode particles in the deciduous forest. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|