1. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 1 Quantifying the flux of carbon dioxide over an urban park area by means of eddy-covariance measurements Klaus Kordowski, Wilhelm Kuttler University of Duisburg-Essen Institute of Geography Department of Applied Climatology and Landscape Ecology 18th Conference on Atmospheric BioGeosciences

2. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 2 Outline  Eddy-covariance for determining fluxes of CO 2 in urban areas: a short overview  Methods and location  Results:  Classifying different flux source areas  Diurnal and seasonal variation of CO 2 - flux  Conclusion

3. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 3 Application of eddy-covariance in urban areas Eddy-covariance (EC)  Measuring turbulent exchange of CO 2  Common method in forest- and agricultural meteorology  Use of EC in urban environment relatively young  Heterogeneity of urban surface  application challanging due to theoretical requirements of EC

4. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 4 Urban CO 2 eddy covariance campaigns Mean diurnal variation of F CO2 according to different authors

5. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 5 Methods and location map sources: Press and Information Office of the German Federal Government (left), land surveying office NRW (right), 2007  Essen (North Rhine – Westphalia, Germany)  210 km²  580.000 inhabitants  Ruhr Area  high density agglomeration

6. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 6  September, 2006 – October, 2007  Measuring height: 26 m (z/z H ~1.73)  Licor 7500 & Metek USA-1 @ 10 Hz  30 min block covariances & averages  Data rejected:  Tower sector: 270° > Φ < 360° (6.6 %)  u* < 0.15 m s -1 Measuring site

7. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 7 Measuring site taken from WEBER et KORDOWSKI (2008)

8. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 8 Mean diurnal cycle Mean diurnal variation (entire period)

9. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 9 Whole dataset vs. approaching flow 31.3% 68.7% T O W E R

10. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 10 Diurnal variation

11. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 11 Seasonal variation

12. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 12 Seasonal variation: day/night comparison 0°-180° „urban“ 180°-270° „park“

13. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 13 Conclusion  Investigated area net source of CO 2  „Assimilation-affected“ diurnal run shifted into positive direction  Park carbon sink in summer during the day  Signal of the urban vegetation can be seen  High deviation of CO 2 -fluxes  highly variable footprint  variable emission patterns  High F CO2 during calm high-pressure weather in winter  Local emission sources

14. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 14 Thank you for your attention! 18th Conference on Atmospheric BioGeosciences

15. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 15 Appendix

16. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 16 Urban CO 2 eddy covariance campaigns AuthorLocationSite characteristics Hight (z/z h ) Dura- tion F CO2 (µmol m -2 s -1 ) minmax GRIMMONDet al., 2002aChicago, USAsuburban4,248 d010 GRIMMOND et al., 2002bBaltimore, USAsuburban/forest1,6> 1 a-256 NEMITZ et al., 2002Edinburgh, Scotland urban/suburban z = 35 m 32 d1038 ANDERSON et TAGGERT, 2002 Denver, USAurban z = 70 m 1 a1040 MORIWAKI et KANDA, 2004 Tokyo, Japansuburban3,91 a525 SOEGAARD et MØLLER- JENSEN, 2003 Kopenhagen, Denmark urban1,71 a536 GRIMMOND et al., 2004Marseille, Franceurban1,8 – 2,828 d030 WALSH et al., 2004Vancouver, Canadasuburban2,30,5 a335 VELASCO et al., 2005Mexico City, Mexicosuburban3,023 d318 VOGT et al., 2005Basel, Switzerlandurban0,1 - 2,130 d316 COUTTS et al., 2007Melbourne, Australia urban/ suburban 2,01 a211 VESALA et al., 2007Helsinki, Finlandsuburban1,60,75 a-435 SCHMIDT et al., 2007Münster, Germanyurban z = 65 m 43 d411

17. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 17 Whole dataset vs. approaching flow Φ (10° classes) 1,5 (q 0,75 -q 0,25 ) q 0,75 MED q 0,25 -1,5 (q 0,75 -q 0,25 ) F CO2 (µmol m -2 s -1 )

18. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 18 PARK/URBAN sectors: frequency Histogramm for F CO2 for both sectors (99,7 % of the dataset is shown)

19. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 19 Seasonal variation

20. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 20 CO 2 flux and concentration: diurnal variation over all sectors

21. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 21

22. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 22 seasonal variation

23. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 23 Diurnal and seasonal variation 0°-150° „urban“ 180°-270° „Park“

24. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 24 Connection to air temperature 0°-180° „urban“ 180°-270° „park“

25. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 25 References 1 of 2 Anderson, D. E. et Taggert, J. (2002). Urban ecosystem-atmosphere exchange of carbion dixide. American Meteorological Society, 4th Urban conference, Norfolk, VA, p. 115-116 Coutts, A. M., J. Beringer, et al. (2007). Characteristics influencing the variability of urban CO 2 fluxes in Melbourne, Australia. Atmospheric Environment 41(1): 51. Grimmond, C. S. B., T. S. King, et al. (2002). Local-scale fluxes of carbon dioxide in urban environments: methodological challenges and results from Chicago. Environmental Pollution 116(Supplement 1): 243-254. Grimmond, C. S. B., B. Offerle, et al. (2002). Observations of local-scale heat, water, momentum and CO 2 fluxes at Cub Hill, Baltimore. Fourth Symposium on the Urban Environment, Norfolk. Grimmond, C. S. B., B. Offerle, et al. (2004). Flux and turbulence measurements at a densely built-up site in Marseille: Heat, mass (water and carbon dioxide), and momentum. Journal of Geophysical Research D: Atmospheres 109(24): 1-19. Moriwaki, R. and M. Kanda (2004). Seasonal and diurnal fluxes of radiation, heat water vapor, and carbon dioxide over a suburban area. Journal of Applied Meteorology 43(11): 1700- 1710. Nemitz, E., K. J. Hargreaves, et al. (2002). Micrometeorological Measurements of the Urban Heat Budget and CO 2 Emissions on a City Scale. Environ. Sci. Technol. 36(14): 3139-3146.

26. I N S T I T U T E O F G E O G R A P H Y D E P A R T M E N T O F A P P L I E D C L I M A T O L O G Y A N D L A N D S C A P E E C O L O G Y 26 References 2 of 2 Schmidt, A., T. Wrzesinsky, O. Klemm (2007). Gap Filling and Quality Assessment of CO 2 and Water Vapour Fluxes above an Urban Area with Radial Basis Function Neural Network. Boundary- Layer Meteorology Soegaard, H. et L. Møller-Jensen (2003). Towards a spatial CO 2 budget of a metropolitan region based on textural image classification and flux measurements. Remote Sensing of Environment 87(2-3): 283. Vesala, T., et al. (2007). Surface-atmosphere interactions over complex urban terrain in Helsinki, Finland. Tellus Velasco, E., S. Pressley, et al. (2005). Measurements of CO 2 fluxes from the Mexico City urban landscape. Atmospheric Environment 39(38): 7433. Vogt, R., A. Christen, et al. (2005). Temporal dynamics of CO 2 fluxes and profiles over a Central European city. Theoretical and Applied Climatology: 46. Vogt, R. (2006). CO 2 flux measurements in a heterogeneous urban environment. 6th International Conference on Urban Climate, June 12 th – 18 th, 2006, Göteborg, Sweden Walsh, C. J., T. R. Oke, et al. (2004). Fluxes of atmospheric carbon dioxide over a suburban area of Vancouver. 5th Symposium on the Urban Environment. Weber, S., Kordowski, K. (2008). Comparison of atmospheric turbulence characteristics and turbulent fluxes from two urban sites in Essen, Germany. Boundary-Layer Meteorology. Submitted.