| Popis: |
A multi-instrument campaign was conducted to investigate the changes in ozone vertical distribution during the annular solar eclipse that occurred in the morning hours (08:10 to 11:15 Indian Standard Time) on 26 December 2019 using both in-situ and remote sensing observations over Gadanki (13.5oN,79.2oE), India. A series of ozonesondes were launched before and after the solar eclipse along with continuous observations from the Brewer MKIII spectrophotometer and Mesosphere-Stratosphere-Troposphere (MST) radar. An enhancement (~30–60 ppbv) in upper tropospheric (10–18 km) ozone was observed immediately after the solar eclipse along with a reduction in the total ozone by 20 DU, at the maximum of solar obscuration. The MST radar observations and interpretation of meteorological reanalysis data and backward trajectory simulations suggest that this ozone enhancement was due to a downdraft from the stratosphere which began a few hours before the eclipse, as well as long-range transport associated with the sub-tropical jet. A mid-tropospheric (4–10 km) ozone enhancement which also occurred during the eclipse was also produced by the action of the sub-tropical jet. However, the cold point tropopause was significantly lower in height at the maximum of the eclipse, and this region subsequently warmed over a period of several hours. The observations during this event further highlight that background dynamics need to be taken into consideration when evaluating the atmospheric effects of different solar eclipses at tropical latitudes. |
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