HDO/H2O isotopic fractionation in simulated cirrus clouds

Tue, 14 Feb 2017 16:06:52 +0100
RSS-News, Teaser

The first experimental determination of HDO/H2O isotopic fractionation factors for ice deposition in simulated cirrus clouds for temperatures betwen 190-233 K could be achieved in the AIDA aerosol and cloud chamber (Lamb et al., PNAS 2017). In collaboration between the University of Chicago, PTB, and KIT unique measurement techniques for water isotopes were developed and applied for dedicated cirrus cloud simulation experiments. A detailed box model analysis including wall effects resulted in equilibrium fractionation factors and kinetic isotope effects with a weaker temperature dependence than extrapolations of previous work suggested. These results are fundamental for inferring processes on Earth and other planets from water isotopic measurements.