Periodic Reporting for period 2 - URBANCO2FLUX (Quantifying the impact of the urban biosphere on the net flux of CO2 from cities into the atmosphere.)
Okres sprawozdawczy: 2017-09-07 do 2018-09-06
The main obstacle in quantifying CO2 capture by vegetation is the fact that CO2 flux observations, are influenced only by the net biogenic flux and do not contain information about the separate photosynthetic and respiratory components. Atmospheric carbonyl sulfide (COS), however, can help with this distinction. COS is a potentially transformative tracer of photosynthesis because its variability in the atmosphere has been found to be influenced primarily by vegetative uptake, scaling linearly with gross primary production (GPP).
The main conclusions of the action are that the urban biosphere is indeed an important contribution to the urban carbon footprint, and that OCS is a suitable tracer for quantifing this contribution. Further work needs to be done to improve the model at the urban scale, especially with respect to the boundary layer (BL)and the air mixing effect. BL depth drives mixing ratios, so it is important to improve the BL scheme for urban atmospheric transport models. We found that mixing ratios are driven by BL depth more so than the emissions. For the case study of San Francisco Bay Area, we found more CO2 emissions in the afternoon but lower mixing ratios because BL gets deeper.
I have established collaborations with other institutes in Barcelona and Oslo regions (Oslo being an additional case study for comparison) to obtain all the input information needed such as: Local Climate Zones (LCZ) to better describe the urban land cover; Urban morphology (building heights/width and streets width);Anthropogenic emissions to simulate air quality; Observed meteorological and air quality data in hourly-base for comparison with the modelled data.Meteorological and air quality data from monitoring stations placed in Barcelona city, regarding the year of 2016, have been analysed to study the real influence of green areas on human comfort indicators (namely temperature, relative humidity, concentrations of NO2, O3 and PM10).