Associate Professor
University of Basel, Diploma in Geography
University of Basel, PhD in Meteorology

 

My research interests are in the area of land-atmosphere-climate interactions, greenhouse gas exchange, and atmospheric turbulence. Our “Micrometeorology Group” uses field and modelling approaches to investigate, quantify and describe physical and chemical processes relevant in land-atmosphere exchange. We work in forest, wetland, tundra and urban ecosystems and study trace-gas fluxes and energy and water budgets. Current research projects include basic turbulence and dispersion studies (exchange processes in forest canopies, vineyards, urban dispersion processes) and applied approaches that link greenhouse gas exchange to emission factors, ecosystem disturbances and land management practices. We use stable isotope approaches to attribute sources and sinks of atmospheric greenhouse gases in cities. Our CFI/BCKDF funded Laboratory for Atmospheric Research on Greenhouse Gas Exchange is equipped with several eddy covariance systems, path-averaging TDLAS systems, trace gas analyzers for carbon and oxygen isotopes, autonomous sampling stations, and radiation instruments. We operate several flux towers for short- and long-term studies across Western and Arctic Canada, including the 35-year old urban flux tower “Vancouver-Sunset”.

2015

KRAYENHOFF, S., SANTIAGO, J.-L. , MARTILLI, A., CHRISTEN, A. and OKE, T.R. 2015 ‘Parametrization of drag and turbulence for urban neighbourhoods with trees’ Boundary-Layer Meteorology DOI 10.1007/s10546-015-0028-6

CRAWFORD, B. and CHRISTEN, A. 2015 ‘Spatial source attribution of measured urban eddy covariance carbon dioxide fluxes’ Theor. Appl. Climatol. 119(3-4), 733-755

PAUL-LIMOGES, E., BLACK, T.A., CHRISTEN, A., NESIC, Z. and JASSAL, R.S. 2015 ‘Effect of clearcut harvesting on the carbon balance of a Douglas-fir forest’ Agr. Forest Meteorol. 203, 30-42.

ADDERLEY, C., CHRISTEN, A. and VOOGT, J.A. 2015 ‘The effect of radiometer placement and view on inferred directional and hemispheric radiometric temperatures of a urban canopy’ Atmos. Meas. Tech. Discuss. 8, 1891–1933

 

2014

CRAWFORD, B. and CHRISTEN, A. 2014 ‘Spatial variability of carbon dioxide in the urban canopy layer and implications for flux measurements’ Atmos. Environ. 98, 308-322.

CHRISTEN, A. 2014 ‘Atmospheric measurement techniques to quantify greenhouse gas emissions from cities’ Urban Climate 10(P2), 241–260

EMMEL, C., PAUL-LIMOGES, E., BOWLER, R., BLACK, T.A. and CHRISTEN, A. 2014 ‘Vertical distribution of carbon dioxidesources and sinks in a recovering mountain pine beetle-attacked lodgepole pine stand’ Agr. Forest Meteorol. 195-196, 108-122

KRAYENHOFF, S., CHRISTEN, A., MARTILLI, A. and OKE, T.R. 2014 ‘A multi-layer radiation model for urban neighbourhoods with trees’ Boundary-Layer Meteorol. 151(1), 139-178

 

2013

EMMEL, C. , PAUL-LIMOGES, E., BLACK, T.A. and CHRISTEN, A. 2013 ‘Vertical distribution of radiation and energy balance partitioning within and above a Lodgepole Pine stand recovering from a recent insect attack’ Boundary-Layer Meteorology 149(2), 133-163

PAUL-LIMOGES, E., CHRISTEN, A., COOPS, N.C., BLACK, T.A. and TROFYMOW, J.A. 2013 ‘Estimation of aerodynamic roughness of a harvested Douglas-fir forest using airborne LiDAR’ Remote Sensing of Environment 136, 225-233.

CHRISTEN, A., OKE, T.R., GRIMMOND, C.S.B., STEYN, D.G. and ROTH, M. 2013 ’35 years of urban climate research at the Vancouver-Sunset flux tower’ FluxLetter 5(2)

KELLETT, R., CHRISTEN, A., COOPS, N., VAN DER LAAN, M., CRAWFORD, B.R., TOOKE, T.R. and OLCHOVSKI, I. 2013 ‘A systems approach to carbon cycling and emissions modelling at an urban neighbourhood scale’ Landscape and Urban Planning 110, 48-58

TOOKE, T.R., COOPS, N. and CHRISTEN, A. 2013 ‘A point obstruction stacking (POSt) approach to wall irradiance modeling across urban environments’ Building and Environment 60, 234-242

 

2012

CHRISTEN, A., MEIER, F. and SCHERER, D. 2012 ‘High-frequency fluctuations of surface temperatures in an urban environment’ Theor. Appl. Climatol. 108(1-2), 301-324

TOOKE, T.R., COOPS, N.C., CHRISTEN, A., GURTUNA, O. and PRÉVOT, A. 2012 ‘Integrated irradiance modeling in the urban environment based on remotely sensed data’ Solar Energy 86(10), 2923-2934

 

2011

CHRISTEN, A., COOPS, N.C., CRAWFORD, B.R., KELLETT, R., LISS, K.N., OLCHOVSKI, I., TOOKE, T.R., VAN DER LAAN, M. and VOOGT, J. A. 2011 ‘Validation of modeled carbon-dioxide emissions from an urban neighborhood with direct eddy-covariance measurements’ Atmospheric Environment 45, 6057-6069.

JÄRVI, L., GRIMMOND, C.S.B. and CHRISTEN, A. 2011 ‘The Surface Urban Energy and Water Balance Scheme (SUEWS): Evaluation in Los Angeles and Vancouver’ J. Hydrol. 411(3-4), 219-237

MEIER, F., SCHERER, D., RICHTERS, J. and CHRISTEN, A. 2011 ‘Atmospheric correction of thermal-infrared imagery of the 3-D urban environment acquired in oblique viewing geometry’ Atmos. Meas. Tech. 4, 909-922

SALMOND, J. A., ROTH, M., OKE, T.R., CHRISTEN, A. and VOOGT, J.A. 2011 ‘Can surface cover tiles be summed to give neighbourhood fluxes in cities?’ J. Appl. Meteor. Climatol. 51, 133-149

CRAWFORD, B., GRIMMOND, C.S.B. and CHRISTEN, A. 2011 ‘Five years of carbon dioxide fluxes measurements in a highly vegetated suburban area’ Atmos. Environ. 45(4), 896-905

 

 

 

 

 

Winter 2017

GEOB204 Introduction to Biometeorology Sections

Basic principles and processes of climatology. Energy and water balance concepts. Weather systems and climate change, microclimate of soils, crops, forests, and animals. Credit will be granted for only one of GEOB 200, GEOB 204, or APBI 244.