Abstract
The term ‘earth-air’ refers to the air in the vadose zone, which can be
modeled as an ideal gas in a closed system, so that the volume of the
earth-air varies as the atmospheric pressure (AP) fluctuates. When AP
rises, the earth-air is compressed and dry external air is forced into
the soil. Conversely, when AP drops, the earth-air expands and moist
earth-air enters the atmosphere. In this work, conclusive proof is
presented for the existence of earth-air passive breathing. This is
accomplished by using an innovatively-designed trap to monitor the
relative humidity of the soil and showing that these moisture records
contain fingerprints that are characteristic of passive breathing. It is
found that the relative humidity in the soil is negatively correlated
with the atmospheric fluctuations, yielding a correlation coefficient of
up to-0.70. This is revealed the universal exchange between the earth-