第九届青年地学论坛

Many studies on ozone during solar eclipses, relying on singular point observations, indicate an elevation in ozone in the mesosphere surpassing the average for the corresponding periods. This observed ozone increase tends to intensify with altitude. In this study, observations from the MLS and simulations from the WACCM-X are employed to examine variations in mesospheric ozone during the solar eclipse event on June 21, 2020. Our findings reveal a significant increase and minor decrease in the daily mean mesospheric ozone during the eclipse. This change is characterized by an altitude-related, peaking around 66 km, with a maximum ozone increase exceeding 12%. However, beyond 75 km, the daily mean ozone undergoes a transition from an increase to a marginal decrease, reaching its minimum at 77 km. At this altitude, ozone initially surges by over 60% at the eclipse onset, subsequently decreasing during the eclipse progression, followed by a resurgence. This oscillation results in a slight decrease in the daily average ozone. At the eclipse commencement, minimal changes are observed in NO_x and HO_x, with the reduction in extreme ultraviolet (EUV) radiation contributing to ozone increase. As the eclipse unfolds, NO experiences a substantial increase, and N weakens significantly, leading to ozone reduction. Then, OH and HO₂ show intensified growth, exacerbating the ozone reduction. Post-eclipse, a noteworthy decline in OH and HO₂ across the entire eclipse path aligns with an ozone increase. NO shows diminishing changes with irregular fluctuations, whereas NO₂ experiences a notable decrease, aligning with the rise in ozone levels preceding ozone recovery. Vertical winds, while a secondary factor, gradually escalate after the eclipse onset. However, the ozone changes induced by vertical winds often oppose the actual ozone alterations.

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