| description abstract | AbstractBecause of Earth?s motion, periodic temperature fluctuations occur in soil on daily and yearly time scales, which inevitably lead to pulsation of the air pressure in the soil. The Earth?air pressure monitoring technique called ?hou-qi? is the basis of a calendar formulated by the ancient Chinese. However, the daily/yearly variation of air pressure in the soil is very weak, according to practical monitoring experiments, so hou-qi has long been considered a pseudoscience. To determine the potential maximum change of Earth?air pressure, identify what is causing the underlying Earth?air pressure variation, and reveal the mechanism, we use a closed system, which is a more appropriate system test of the possible validity of hou-qi, to monitor Earth?air pressure variation in this paper. The results show that there are potential air pressure fluctuations of about 120?190 hPa in closed soil over the daily/yearly temperature range of 5°?40°C. This provides ample magnitude for hou-qi. The largest contribution made to Earth?air pressure variation was pressurization due to air warming, with vapor due to water evaporation and desorbed gas having smaller effects. The soil?s water content has a significant effect on Earth?air pressure amplitude. Dry soil contributes almost no water vapor, but the adsorbed gases from dry soil have up to a 38-hPa influence on air pressure. The soil?s salt content also has an important regulating role on Earth?air pressure and can reduce the influence of vapor pressure. This paper provides a scientific basis for the ancient Earth?air monitoring system of hou-qi and also has important significance for hydrometeorology and research on the ancient Chinese civilization. | |
