C
C. Hak
Researcher at Heidelberg University
Publications - 5
Citations - 486
C. Hak is an academic researcher from Heidelberg University. The author has contributed to research in topics: Differential optical absorption spectroscopy & Boundary layer. The author has an hindex of 5, co-authored 5 publications receiving 445 citations. Previous affiliations of C. Hak include University of Gothenburg & Norwegian Institute for Air Research.
Papers
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Journal ArticleDOI
MAX-DOAS measurements of formaldehyde in the Po-Valley
A. Heckel,Andreas Richter,T. Tarsu,Folkard Wittrock,C. Hak,I. Pundt,W. Junkermann,John P. Burrows +7 more
TL;DR: In this article, the results of the first measurement campaign of the EU FORMAT project in summer 2002 near Milan, northern Italy, ground-based scattered light differential optical absorption spectroscopy (DOAS) measurements were performed using a new multi-axis instrument.
Journal ArticleDOI
Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air
C. Hak,I. Pundt,S. Trick,S. Trick,Christoph Kern,Ulrich Platt,J. Dommen,Carlos Ordóñez,André S. H. Prévôt,Wolfgang Junkermann,C. Astorga-Llorens,B.R. Larsen,Johan Mellqvist,A. Strandberg,Young J. Yu,Bo Galle,Jörg Kleffmann,J.C. Lörzer,Geir O. Braathen,Rainer Volkamer +19 more
TL;DR: In this paper, an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) is presented, including differentially optical absorption spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine).
Journal ArticleDOI
Inversion of tropospheric profiles of aerosol extinction and HCHO and NO 2 mixing ratios from MAX-DOAS observations in Milano during the summer of 2003 and comparison with independent data sets
Thomas Wagner,Steffen Beirle,Theo Brauers,T. Deutschmann,Udo Frieß,C. Hak,C. Hak,J. D. Halla,Klaus-Peter Heue,Wolfgang Junkermann,Xin Li,U. Platt,I. Pundt-Gruber,I. Pundt-Gruber +13 more
TL;DR: In this article, profile inversion was applied to MAX-DOAS observations during a measurement campaign in Milano, Italy, September 2003, which allowed simultaneous observations from three telescopes (directed to north, west, south).
Journal ArticleDOI
A photochemical modeling study of ozone and formaldehyde generation and budget in the Po basin
L. Liu,L. Liu,S. Andreani-Aksoyoglu,Johannes Keller,Carlos Ordóñez,Carlos Ordóñez,Wolfgang Junkermann,C. Hak,C. Hak,Geir O. Braathen,Geir O. Braathen,Stefan Reimann,C. Astorga-Llorens,Martin G. Schultz,André S. H. Prévôt,Ivar S. A. Isaksen +15 more
TL;DR: In this paper, a photochemical dispersion model, CAMx, was used to simulate a high ozone episode observed in the Po basin during the 2003 FORMAT (Formaldehyde as a Tracer of Oxidation in the Troposphere) campaign.
Journal ArticleDOI
Photochemical modelling in the Po basin with focus on formaldehyde and ozone
L. Liu,L. Liu,F. Flatoy,Carlos Ordóñez,Geir O. Braathen,C. Hak,Wolfgang Junkermann,S. Andreani-Aksoyoglu,Johan Mellqvist,Bo Galle,André S. H. Prévôt,Ivar S. A. Isaksen +11 more
TL;DR: In this article, a 3D regional chemical transport model (NILU RCTM) was used to interpret the observations focusing primarily on HCHO and ozone, and the performance of the model was assessed by comparing model results with ground-based and aircraft measurements.