Time rate of atmospheric 3He/4He change: An attempt to measure anthropogenic CO2 flux

Taking into account recently published data, the author assesses possible time rate change of atmospheric 3He/4He ratio. Three independent estimations are considered and the common value of the 3He/4He variations is proposed. The most reliable decreasing rate of atmospheric 3He/4He ratio, 0.032 ± 0.013 %/year is consistent with the anthropogenic emission of crustal helium of 3.1x1011 mol/year estimated by the statistics of global fossil fuel exploitation and the probable carbon/helium ratio in the fuel. Because of the inert chemistry of helium, atmospheric 3He/4He change may provide a marker against which to calibrate the absolute flux and retention of anthropogenic CO2 in the atmosphere

Time rate of atmospheric 3He/4He change: Constraint from South Pacific deep seawater

A recent study of atmospheric 3He/4He ratio has suggested that it is decreasing with time, perhaps due to anthropogenic release from oil and natural gas wells of crustal helium with a low 3He/4He ratio. A couple of objections have been made against this hypothesis based on new observations. It is important to verify the time rate of atmospheric 3He/4He change, since this has serious implications for the field of helium isotope geochemistry. I present here the time rate change of -0.094±0.156 %/year (2σ errors) based on the 3He/4He ratio obtained from South Pacific deep seawater. Taking into account four other independent measurements on the time rate, I can calculate the average time rate of -0.028±0.030 %/year (2σ), which is consistent with a zero rate of change in atmospheric 3He/4He ratio. However the average time rate is also consistent with the time rate of -0.033 %/year estimated from anthropogenic release of crustal helium. Thus the problem is not yet solved and further study is desirable

DYNAMIC RESPONSE OF THE HYGROMETER USING FINE THERMOCOUPLE PSYCHROMETER

A new method to obtain the frequency response character of the hygrometer using a fine thermocouple psychrometer by introducing the new concept, that the internal energy of the environment is constant, is presented with a practical example