Author(s)

M. L. Sánchez, M. A. García, B. de Torre & I. Pérez

Abstract

This paper presents the main experimental results of ozone and carbon dioxide concentrations measured in a rural area in the upper Spanish plateau during 2000–2003 from a climatological perspective. Special attention is addressed to characterise the annual cycle and describe the trends observed during the entire period of the study. Keywords: CO2 annual cycle, O3 annual cycle, CO2 trends, O3 trends. 1 Introduction Indicators of human influence on the atmosphere during the industrial era have shown that concentrations of atmospheric greenhouse gases and their radiative forcing have continued to increase as a result of human activities. Among the atmospheric components linked to positive radiative forcing, O3 and CO2 are the subject of increasing concern [1]. Experimental evidence has shown that over the last few decades’ background O3 in the troposphere has doubled compared to the pre-industrial years [2]. The impact of global increases in background concentrations appears to be evident in the increase in mean annual concentrations [3]. Conversely, analysis of UK monitoring data, also consistent with reports elsewhere in Europe and the United States, has revealed that O3 peaks have tended to decline over the past decade [4]. Over the two past decades the steadily increasing CO2 trend has been estimated at around 1.5 ppm year -1 [5]. Nevertheless, despite the increasing number of monitoring stations around the world, data in rural locations are still sparse. This is especially true in Southern Europe, and specifically in Spain. In February 2000 we installed the first rural station in the region of Castile and Leon located on the upper Spanish plateau. O3, CO2 and concurrent meteorological variables were measured for almost four consecutive years. The

Keywords

CO2 annual cycle, O3 annual cycle, CO2 trends, O3 trends.