Croatica Chemica Acta, Vol. 81 No. 2, 2008.
Izvorni znanstveni članak
Trends, Distribution and Frequency Analysis of Ozone Data from Three Monitoring Stations in Baton Rouge, Louisiana for the Years 1995 to 2005
Leo Klasinc
; Ruđer Bošković Institute, Zagreb, Croatia
Nenad Kezele
; Ruđer Bošković Institute, Zagreb, Croatia
Matevz Pompe
; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
Sean P. McGlynn
; Department of Chemistry, The Louisiana State University, Baton Rouge, LA, USA
Sažetak
Troposphere ozone concentrations exhibit pronounced, characteristic diurnal and seasonal cycles.
These cycles are usually well defined. However, additional oscillations also occur; these
are generally much smaller in amplitude than the 1-day or 1-year cycles and they might be attributable
to anthropogenic influences (e.g., specific man-induced meteorological and chemical
influences on an individual monitoring station, periodic maintenance activities, etc.). Indeed, it
is possible that the spectral analysis of photochemical pollution data could pinpoint hidden
conditions that affect particular monitoring stations. Such an analysis, one based on Fourier
transform methods, was applied to long-term data from 3 American monitoring stations. As
would be expected, strong signals were found for the 1-day and 1-year periods; however, some
weaker signals, ones probably associable with anthropogenic affairs, were also observed. A
principal component analysis (PCA) was applied to the transformed data sets in order to identify
these periods. Periods of 3.5-days and 7-days, as well as a number of other cycles, were
found and can be considered to be markers of anthropogenic influences. European and American
data will be compared and the effects of Hurricane Katrina will be examined.
Ključne riječi
ozone; frequency analysis; long-term data; PCA
Hrčak ID:
28494
URI
Datum izdavanja:
30.6.2008.
Posjeta: 1.278 *