The intensification of metallic layered phenomena above thunderstorms through the modulation of atmospheric tides

Abstract

<p><strong>Abstract.</strong> We present a multi-instrument experiment to study the effects of tropospheric thunderstorms on the mesopause region and the lower ionosphere. The sodium (Na) lidar observation and the ionospheric observation by two digital ionospheric sounders are used to study the variation of the neutral metal atoms and metallic ions above thunderstorms. The enhanced ionospheric sporadic <i>E</i> layer with a downward tidal phase is observed followed by a subsequent intensification of neutral Na density with an increase of 600 cm<sup>−3</sup> in the mesosphere. In addition, the Na neutral chemistry and ion-molecule chemistry reactions are considered in the Na chemistry model to simulate the dynamical and chemical coupling processes in the mesosphere and ionosphere above thunderstorms. The enhanced Na layer in the simulation using the ionospheric observation as input is in agreement with the Na lidar observation. We find that the intensification of metallic layered phenomena above thunderstorms is associated with the atmospheric tides, as a result of the troposphere-mesosphere-ionosphere coupling.</p>

Response to Reviewers

“…Response: Thanks for your comments. In the SEA, some undesired recurrence of lightning events before time zero would contaminate the result (Yu et al, 2017). But on the whole, the enhancement of Na density at altitudes of 85-98 km exceeds the significant level at 17-24 h, 85-98 km after lightning with the maximum increase of ∼600 cm-3 at t=19 h, at an altitude of 93 km.…”

“…We have explained it in more details in the revised manuscript. In the SEA, to analyze such a large data set, the lightning data from WWLLN and observations by the Na resonance fluorescence lidar at Haikou were sorted to hourly data to investigate the connection between thunderstorms and neutral metal Na layer (Yu et al, 2017). By aligning the Na density data according to the time of the lightning event ("trigger" time) and calculating the average response of all the Na layer profiles that were acquired ∆t hours either before and after lightning, any consistent influence of lightning and thunderstorms on the Na layer will be reinforced while other random influences unassociated with lightning will be canceled out.…”

“…By aligning the Na density data according to the time of the lightning event ("trigger" time) and calculating the average response of all the Na layer profiles that were acquired ∆t hours either before and after lightning, any consistent influence of lightning and thunderstorms on the Na layer will be reinforced while other random influences unassociated with lightning will be canceled out. The number of triggers is plotted in Figure 1 as Yu et al (2017). The 0 time is the trigger time in the SEA.…”

“…Changes: Please see page 3 lines 26-29. "Some undesired recurrence of lightning events before time zero would contaminate the result (Yu et al, 2017). The Na layer is obviously intensified up to 500 cm-3 after lightning.…”

“…Response: The 0 time is the trigger events for SEA. We further analyzed the cases distributed on 28 thunderstorms in Yu et al (2017). In the case study, the averaged lightning stroke rate was used as an indicator of the intensity of thunderstorms at the beginning of triggers.…”