Analysis of temperature variation characteristics in relative recording rooms of geomagnetic reference stations

The variation of temperature in the geomagnetic relative recording room can cause deviations in the relative recording data, thereby affecting the geomagnetic baseline value. This article uses observation data of annual and daily temperature differences in relative recording rooms from 40 geomagnetic reference stations in China from 2021 to 2023, and analyzes the relationship between the construction of relative recording rooms at each station and temperature changes based on the data results. The research results show that about 70% of the total statistics are stations have an annual temperature difference of less than 10℃ in the relative recording room, and about 85% of stations have a daily temperature difference of less than 0.3 ℃. The findings suggest that a well-insulated geomagnetic relative recording room has smaller impact on temperature. Fully underground recording rooms exhibit the best insulation performance, followed by the insulation effect of the semi underground type recording room. Conversely, fully above-ground structures have poorer insulation, although a thicker insulation layer can still meet regulatory requirements. In the construction or renovation of relative recording rooms, priority should be given to selecting a fully underground structure for geomagnetic stations with significant annual temperature changes. For semi-underground recording rooms or fully above-ground buildings, increasing the thickness of the insulation layer is recommended.