Das Projekt "Der globale Kohlenstoffkreislauf und dessen Stoerung durch Menschen und das Klima - II die Atmosphaere" wird vom Umweltbundesamt gefördert und von Universität Heidelberg, Institut für Umweltphysik durchgeführt. Two global networks estabilished by the Uni HD for 14CO2 and 85 Krypton observations shall be continued. Bi-weekly integrated samples for isotope analyses are collected at eight (14CO2) respectively ten (85Kr) background as well as continental stations distributed from 83'N to 70'S. High presicion 14CO2 analyses will be performed at the Uni HD, the 85Kr analyses are run by the BfS (subcontractor of Uni HD: Dr. W. Weiss, Bundesamt fuer Strahlenschutz, Institut fuer Atmosphaerische Radioaktivitaet, Freiburg). In addition, a new technique for 13CO2 measurements on whole air flask samples shall be developed by Uni HD with a pilot sampling to be started at the German stations Westerland and Schauinsland, and, in collaboration with the Spanish Instituto Nacional de Meteorologia (Dipl.Phys. Emilio Cuevas, subcontractor), at Izana, Tenerife. Intercalibration experiments will be performed with the LPCM (Dr. P. Monfray).
Das Projekt "Untersuchungen zu Speicherprozessen und zur Verweilzeit von Abflussbestandteilen im Rietholzbach-Becken" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Geographisches Institut, Abteilung Hydrologie durchgeführt. A detailed hydrograph analysis in the hydrological research basin Rietholzbach provided essential insights into the runoff generating mechanisms in prealpine catchments with a view to the temporal reactions of the hydrological system. The process studies are now further pursued on the basis of field sampling of environmental isotopes (oxygen-18, deuterium, tritium, krypton-85). Automatic samplers allow to obtain time and event dependent water probes which are analysed in the isotopic laboratories of the Geological Institute ETHZ and of the Dept. of Physics, Univ. of Berne. These isotopes serve as tracers to analyse the various runoff processes forming the basin water system in a large range of temporal and spatial scales. The results are an important basis for the regionalisation of subsurface and groundwater flow including dissolved constituents under different climatic and hydrogeologic conditions.