Two decades of environmental isotope records in Croatia; reconstruction of the past and prediction of future levels.

Abstract

A two-decade-long record of environmental isotopes ( (super 2) H, (super 3) H, (super 14) C, (super 18) O) in Croatia is presented and the data are statistically analyzed. The atmospheric (super 14) C activity for the period before the actual measurements started is reconstructed by measuring tree rings from the clean-air sites, and the past tritium activity in precipitation is estimated by the correlation of our data with the Vienna station record. The long-term (super 3) H record helped to determine a locally contaminated sampling site, and new clean sites are put into operation. The (super 14) C data were fitted by an analytical function and the prediction of future levels is given assuming that the rate of the (super 14) C releases remains constant. From the long-term stable isotope data record, the local meteoric water line and the temperature gradient of delta (super 18) O in precipitation are determined.