Environmental measurements at Monte Cimone GAW station

Abstract

Continuous atmospheric CO 2 measurements performed by IAFMC at Mt. Cimone Observatory in the period 1980–2009 were analysed in order to select data representing background concentrations. A filtering technique was used to smooth background data and to separate the annual cycle from the long-term increase. The average growth rate of CO 2 was found to be 1.708 ± 0.003 ppm/year, while annual cycle amplitude was 11.42 ± 1.48 ppm. From spectrum analysis of detrended data significant interannual contributions (periods of about four years and of about 2.5 years) were found. Moreover, a strong positive correlation between CO 2 growth rate and global temperature anomalies was found. A statistical model was applied on column ozone data measured in Sestola in the period 1979–2010 in order to separate natural cyclic contributions from the anthropogenic contribution, which is given by a piecewise-linear trend with a turning point in January 1996. We estimated a trend equal to –1.61 ± 0.41 D.U./year before turning point, and a trend of +1.06 ± 1.18 D.U./year after turning point. Finally, a net decrease in annual maximum of near-noon UV index was found from 2005 in Sestola and in the period 1996–2009.