A Note on the Deuterium Content in the Atmosphere and the Hydrosphere

Abstract

The deuterium content in w a ter in the primitive ocean was estimated under the assumption of gradual accumulation of oceanic waters at a constant rate which is a difference of supply from the earth's interior and loss of water through photo-dissociation followed by escape of hydrogen into the outer space. The result of calculation showed that the deuterium content in the primitive ocean was 3-4% less than that in the present surface water.
As to the distribution of deuterium in the ocean, no significant correlation was found between deuterium content, salinity and depth, except for those in sea areas where the rate of evaporation exceeds considerably that of precipitation or the sea water is mixed with a greater amount of melt water.
Concerning d euterium content of meteoric water, fractionation between both vapor-liquid and vapor-ice systems were calculated and it was pointed out that the latter is more important in considering the deuterium content in rain water. It is also to be noted that fractionation factor of deuterium and protium in vapor-ice system reaches its maximum at about 5°C (at 0°C for vapor-liquid system) and vapor pressure of HDO ice is higher than that of H₂O ice for temperatures below 25°C.
A balance sheet of deuterium on the earth was made together with the transfer rates among different reservoirs of water. As a result, it was concluded that concentration of deuterium in oceanic rain water (-6.9 %) is 2 % higher than that in continental rain (-8.9%) and 55% of water in rain on land is derived from the vapor coming from the oceans.