RT Journal Article
T1 Temporal and spatial variabilities of total ozone column over Portugal
A1 Antón, M.
A1 Bortoli, D.
A1 Costa, M. J.
A1 Kulkarni, P. S.
A1 Domingues, A. E.
A1 Barriopedro Cepero, David
A1 Serrano, A., A.
A1 Silva, A. M.
AB This paper focuses on the spatial-temporal structure of total ozone column (TOC) over Portugal. This relevant region of southwestern Europe has not been evaluated yet in detail due to the lack of continuous and well-covered ground-based TOC measurements. The data used in this study are derived from the NASA's Total Ozone Mapping Spectrometer (TOMS) for the period 1978-2005. The TOC spatial behavior shows no significant longitudinal variability (smaller than 3%). In contrast, the variation in latitude changes between 3.5% and 6% depending on the calendar month. The TOC in the northern Portugal is, on average, higher than that recorded in the South. The temporal variability was analyzed for three scales: long-term, seasonal and short-term. The long-term TOC changes are analyzed between 1978 and 1999 by means of linear least squares fits. The results show an annual TOC trend of (2.65 +/- 0.70)%/decade which is statistically significant at the 95% confidence level. This TOC decrease is smaller than the trends obtained in other midlatitudes regions which could be partially explained by the compensation due to the observed increase in the tropospheric ozone over the Iberian Peninsula. A trend analysis performed for each individual month shows a statistically significant TOC decline between March and October, with a maximum linear trend value of (-7.30 +/- 45)%/decade in May. The amplitude of the seasonal TOC cycle over Portugal shows a slight dependence in latitude, varying from 28.6 DU (37.5 degrees N) to 33.6 DU (41.5 degrees N). Finally, the short-term variability showed a notable seasonal behavior, with maximum day-to-day TOC changes in winter (similar to 6%) and minimum in summer (similar to 3%). In addition, the persistence (characterized by the autocorrelation coefficients) strongly decreases after a few days (except in summer months).
PB Elsevier Science INC
SN 0034-4257
YR 2011
FD 2011-03-15
LK https://hdl.handle.net/20.500.14352/44104
UL https://hdl.handle.net/20.500.14352/44104
LA eng
NO © 2010 Elsevier Inc. The authors thank the NASA TOMS Science Team for the satellite data used in this paper. Manuel Anton thanks the Ministerio de Ciencia e Innovacion and Fondo Social Europeo for the award of a postdoctoral grant (Juan de la Cierva). Author (Pavan S Kulkarni) is thankful to the Geophysics Centre of the University of Evora (CGE-UE) for the fellowship in the project 'SPATRAM-MIGE Polar Project', funded by the Portuguese Science Foundation - FCT. This work was partially supported by Ministerio de Ciencia e Innovacion under project CGL2008-05939-C03-02/CLI and by Fundacao para a Ciencia e a Tecnologia though projects PROPOLAR and PTDC/CTE-ATM/102142/2008.
NO Ministerio de Ciencia e Innovación
NO Fondo Social Europeo
NO Geophysics Centre of the University of Evora (CGE-UE)
NO Portuguese Science Foundation - FCT
NO Fundaçao para a Ciencia e a Tecnologia
DS Docta Complutense
RD 13 abr 2025