CR 34:161-167 (2007)  -  doi:10.3354/cr034161

ABSTRACT: We tested a method for high-resolution measurement of CO₂ within the urban canopy layer for urban land-use types in Essen, Germany (51°28’N, 7°0’E; population: 582000; area: 210 km²) between 2002 and 2005. CO₂ was measured during calm weather on 50 mobile trips, and analysis of this data showed that the urban CO₂ mixing ratio can be represented both temporally and spatially. Mobile measurement allows basic recurring CO₂ patterns to be recorded, since close similarities can be observed in CO₂ patterns within the urban canopy layer at different times if weather conditions are similar or the measurements are taken at the same time of the day. This method of measurement also allows the researcher to make fewer measuring trips than was initially planned. Statistical analysis confirmed that 4 measuring trips per season (2 for daytime and 2 for night time) are sufficient to obtain a representative and reliable picture of CO₂ within the urban canopy layer.

KEY WORDS: Urban CO₂ · Urban environment · Mobile measurements · Air pollutants · Statistical analysis · Essen