The first mathematical models of dynamic meteorology: The Berlin prize contest of 1746

Abstract

Carbon dioxide is one greenhouse gas, which is responsible for the anthropogenic induced climate change. Above all, urban agglomerations like the German Ruhrgebiet are a potential CO 2 -source due to the usage of fossil energy sources. For example, in the city of Essen, Germany (North Rhine-Westphalia; 51°28'N. 7°0'E; 580,000 inhabitants; area = 210 km 2 ) the urban carbon dioxide was determined by taking 50 survey tests with the aid of the mobile laboratory from the Dept. of Applied Climatology, University of Duisburg-Essen, Campus Essen, Germany. These measurements were taken along a route of 63 kilometers. The purpose of this study was to analyze the relationship between urban CO 2 concentration levels and temporal variables (e.g., air temperature, atmospheric stability) and invariable influencing factors (e.g., surface configuration) within the urban canopy layer. The results are based on a one-year period of data collection (December 2002-November 2003) with additional data collection in 2004 and 2005. This study proves how the urban CO 2 concentration is influenced by spatial variations as well as diurnal and seasonal meteorological conditions. Thus, approximately more than 70 % of the near surface urban CO 2 is mostly affected by traffic density and atmospheric stability. In addition, it is proven that CO and NO can help to verify the dependence on CO 2 of the traffic density. Thus, the appearance of CO 2 shows a close interdependence between CO (R 2 day time = 0.57) and NO (R 2 day time = 0.69). Other factors that were identified and analyzed include air temperature (9 %), relative humidity (6 %), the urban vegetation (5 %), or the surface configuration (4 %). However, these factors contributed only slightly in terms of explaining the impact of diurnal or seasonal urban CO 2 pattern. Hence, it is clear that there should be mobile survey tests for at least one year while considering the urban types of land use. Otherwise, it is not possible to represent the seasonal and spatial variations of the near surface urban CO 2 .