A new interpretation of the meteoric water line

Simple Rayleigh condensation and Rayleigh evaporation models for evaluating correlation between the isotopic composition of hydrogen and oxygen in meteoric water are analysed in terms of influences of accumulation of conversion products, of mixing of vapour and liquid phases, of extension or contraction, respectively. The effect of simultaneous conversion in both directions can be taken into account by introducing the relative amounts η and (1-η) of condensation and evaporation. The model yields m 7.82 and q = 8.90 instead of the empirically found values m = 8.08 +- 0.80 and q = 9.57 +- 0.62 in the meteoric water line δD = mδ18O + q and a satisfactory understanding of the corresponding δD - δ18O correlations of the Northern and the Southern hemisphere with their different quantitative proportions of ocean and land masses. (author)