Sub-project 4

Quantification of turbulent urban surface-atmosphere exchange of size-resolved particles, heat, water vapour and CO2

To verify the output of numerical models reliable and representative data from field studies are needed. There is still a limited base of knowledge on urban surface atmosphere fluxes, especially for particles and carbon dioxide. To date, it is not well quantified under which conditions the urban area is a source or sink for particles of different sizes. This can only be quantified by size-resolved measurements of urban surface atmosphere exchange. The quantification of particle emission factors for different urban sources and source types will be important for the implementation of microscale air quality / dispersion models. For these reasons sub-project 4 (TP 4) aims to quantify following turbulent exchange fluxes of different pollutants and meteorological quantities between the urban surface and the atmosphere in Berlin: size-resolved particle fluxes (e.g. ultrafine particles), carbon dioxide and surface energy balance (sensible heat, latent heat, net radiation).

TP 4 will establish and approve a concept for gathering urban surface-atmosphere fluxes of important quantities using eddy covariance technique during long-term observations (LTO) and intense observation periods (IOP). The data is of significant importance in the implementation of numerical models. TP 4 will conduct measurements in Berlin and assess whether the measurement concept is generally transferable to other cities. It will closely cooperate with other TPs to establish joint study areas, especially with TU Berlin and mobile measurement approaches in Berlin.

TP 4 will also participate in model validation studies and application tests jointly performed by partners from Modules B and C.