Figures of the Article

• Spectrograms of the high-frequency fluctuations of barometric pressures caused by the squall line
• The passage of the squall line on 21 September 2017 （Yang，Yang，2020） and distribution of deep wells （black triangles） and meteorological stations （green triangles） in North China
• The original changes of groundwater levels （black traces），barometric pressures （green traces），and air temperatures （red traces） in response to the passage of the squall line （denoted by blue stripe） for the four wells
• The detailed variations of groundwater levels （black traces），barometric pressures （green traces），and air temperatures （red traces） in response to the passage of the squall line from 18:00 to 24:00 on 21 September 2017 for the four wells
• Detailed comparison of the fluctuations of groundwater levels （red lines） with barometric pressure changes （green lines） as a squall line passed the four deep wells
• The cross-correlation coefficients between the band-pass filtered （15−25 cpd） groundwater levels and barometric pressures for the deep wells
• The simple linear regression relationships between groundwater levels and barometric pressures after eliminating time delays in the 15−25 cpd frequency band