@conference {jaehne2010a,
	title = {Wind/wave-tunnel measurements of chemical enhancement of the carbon dioxide gas exchange rate},
	booktitle = {6th Int. Symp. Gas Transfer at Water Surfaces, Kyoto, May 17--21, 2010},
	year = {2010},
	note = {abstract},
	doi = {10.5281/zenodo.14928},
	author = {Bernd J{\"a}hne and Kai Degreif and Joachim Kuss}
}
@incollection {garbe2007c,
	title = {Estimating the viscous shear stress at the water surface from active thermography},
	year = {2007},
	pages = {223--239},
	publisher = {Springer-Verlag},
	abstract = {A novel technique is presented that makes it possible to measure the viscous shear stress from active thermography. With a CO2 laser, patterns are written to the sea surface. This temperature structure is distorted by the linear velocity profile in the viscous boundary layer. Due to the non-zero penetration depth of both the laser and the infrared camera, this vertical velocity profile can be resolved. By resolving the velocity profile, the viscous shear stress can be extracted from the recorded image sequences. At the same time, the flow field at the water surface can be measured accurately. Estimating both quantities is only possible by modeling the imaging process as well as the velocity profile in the boundary layer. The model parameters can then be computed in a standard parameter estimation framework. This novel technique was tested both on simulated data and on measurements conducted in a small annular wind-wave flume. The friction velocity computed in this fashion compared favorably to independent measurements. Although not tested yet, this technique should be equally applicable to field measurements.},
	doi = {10.1007/978-3-540-36906-6_16},
	author = {Kai Degreif and Bernd J{\"a}hne and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Christoph S. Garbe and Handler, R. A.}
}
@incollection {falkenroth2007a,
	title = {Visualisation of oxygen concentration fields in the mass boundary layer by fluorescence quenching},
	year = {2007},
	publisher = {Springer Verlag},
	abstract = {Laser-Induced Fluorescence (LIF) is applied to observe directly the mechanism of gas exchange in the aqueous viscous boundary layer at a free water surface. In order to make dissolved oxygen visible, a new class of fluorescent dyes is used with a life time in the order of microseconds so that the quenching constant for dissolved oxygen is sufficiently high for sensitive measurements. Depth profiles of the O2 concentration near the water surface are obtained by a vertical laser sheet at a rate of 185 frames per second. This technique is capable of a measurement sector up to several centimetres down from the water surface with a resolution in the order of 50-100 um. For a small circular wind/wave facility a correlation between wind speed and gas-exchange rates calculated from the extrapolated mean boundary-layer thickness are presented as well as the results of parallel measurements with a budget method for other gases with known Schmidt numbers.},
	doi = {10.1007/978-3-540-36906-6_4},
	author = {A. Falkenroth and Kai Degreif and Bernd J{\"a}hne and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Handler, R. A.}
}
@conference {degreif2006a,
	title = {Gas exchange measurements: the chemically enhanced gas transfer of carbon dioxide at the water surface},
	booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Spring Conference, Heidelberg, 15.-17.03.2006},
	year = {2006},
	publisher = {Deutsche Physikalische Gesellschaft},
	organization = {Deutsche Physikalische Gesellschaft},
	url = {http://www.dpg-verhandlungen.de/2006/heidelberg/up.html},
	author = {Kai Degreif and Joachim Kuss and Bernd J{\"a}hne}
}
@conference {degreif2006b,
	title = {Gas exchange measurements: transition of the boundary conditions from a flat to a rough water surface},
	booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Spring Conference, Heidelberg, 15.-17.03.2006},
	year = {2006},
	publisher = {Deutsche Physikalische Gesellschaft},
	organization = {Deutsche Physikalische Gesellschaft},
	url = {http://www.dpg-verhandlungen.de/2006/heidelberg/up.html},
	author = {Kai Degreif and Bernd J{\"a}hne}
}
@phdthesis {degreif2006,
	title = {Untersuchungen zum Gasaustausch - Entwicklung und Applikation eines zeitlich aufgel{\"o}sten Massenbilanzverfahrens},
	year = {2006},
	publisher = {Institut f{\"u}r Umweltphysik, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	abstract = {The study presents a novel technique for measuring time resolved gas transfer rates at the water surface. By applying this new mass balance technique neither absolute concentrations of the trace gases nor the measurement of their concentrations in the water phase is required. Gas fluxes are calculated exclusively by the temporal change of the air-sided concentrations in an evasion experiment. The high temporal resolution of this procedure allows fast measurements under different conditions. Systematic measurements of gas exchange rates are now feasible within hours. By using UV-spectroscopy, simultaneous concentration measurements of volatile aromatics in the air and water phases verified the results obtained by the presented technique. Within the framework of the UV-measurements a method was developed to determine the air-sided concentrations of the aromatics precisely, even at low spectral resolution of the spectrometer. The differential optical absorption spectroscopy was successfully applied to a wide concentration range of these tracers. Reliable gas transfer velocities are now also available for very low wind speeds and friction velocities. The transition of the Schmidt number exponent from a flat to a rough water surface was reproduced. The transition begins at unexpectedly low wind speeds and extends over a wide range of wind speeds. For the first time the effect of chemically enhanced gas-exchange was demonstrated under a variety of chemical and physical conditions.},
	url = {http://www.ub.uni-heidelberg.de/archiv/6120},
	author = {Kai Degreif}
}
@conference {jaehne2005f,
	title = {The Heidelberg Aeolotron: new perspectives for laboratory investigations of small-scale air-sea interaction},
	booktitle = {Poster presented at: International Liege Colloquium on Ocean Dynamics, Gas Transfer at Water Surfaces},
	year = {2005},
	doi = {10.5281/zenodo.15417},
	author = {Bernd J{\"a}hne and Uwe Schimpf and Christoph S. Garbe and Kai Degreif}
}
@conference {degreif2004,
	title = {Gas exchange experiments using time resolved UV-spectroscopy},
	booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Spring Conference, Munich, 22.-26.03.2004},
	year = {2004},
	publisher = {Deutsche Physikalische Gesellschaft},
	organization = {Deutsche Physikalische Gesellschaft},
	abstract = {The air sea gas exchange plays a key role in the development of the earth{\textquoteright}s climate. The oceans can act as a source or sink for climate relevant gases such as carbon dioxide, methane or dimethyl sulphide. Hydrodynamics in the viscous boundary layer at the free ocean surface and therefore the gas transfer across the interface are not well understood yet. UV-spectroscopy provides a direct and fast measuring method for gaseous or volatile tracers in the air and water phase. A wide range of hydrodynamic parameters, i.e. Schmidt numbers and solubilities is feasible with volatile hydrocarbons such as benzene or fluorobenzene. Multiple tracers may be observed simultaneously with the same non-invasive measuring technique. Laboratory experiments are performed at a 120 cm diameter circular wind-wave-facility in Heidelberg. A detailed study of gas transfer rate{\textquoteright}s dependence on the mean squared surface wave slope s^2, friction velocity u*, as well as on the Schmidt number Sc and solubility of the tracers will be performed. Also the influence of surface films or an increased viscosity is going to be examined. Preliminary results and further prospects are presented.},
	url = {http://www.dpg-verhandlungen.de/2004/up_15.html},
	author = {Kai Degreif and Bernd J{\"a}hne}
}
