| Summary: | Accurate and continuous measurement of the subsoil CO<sub>2</sub> is critical to better understand the terrestrial and atmosphere gas transfer process. This work aims to develop and field test a specific flow system to continuously measure the soil gas concentration (χc) and understand its main physical drivers. Hourly data measured in situ were collected through two dedicated wells at 1 m and 6 m depth coupled with micrometeorological measurement. Our study shows that χc at -1 m was at the lowest in winter and highest in summer. Meanwhile, the seasonal variation of χc at -6m is somewhat unclear. While it is inevitable that temperature plays a significant role, this factor related to biological activity cannot fully explain the variation. The decrease in χc at both depths in summer coincides with an increase of friction velocity, especially during dry periods with R<sup>2</sup> of 0.68, which shows strong empirical evidence that wind turbulence plays a significant role in driving the deep soil CO<sub>2</sub>. A monitoring strategy for gas measurement combining borehole and micrometeorological measurement offers excellent long-term monitoring possibilities to derive the vertical distribution of CO<sub>2</sub> and better understand the main physical drivers of gas exchange.
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