1. Institute
for Water and Environmental Problems, Siberian Branch of the Russian Academy of Sciences, Barnaul 656038, Russia
2. Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
3. Oeschger
Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland
4. Department
for Chemistry and Biochemistry, University of Bern, Freiestrasse
3, 3012 Bern, Switzerland