| Autor: |
Vania Fatima Andrioli, Jiyao Xu, Paulo Prado Batista, Laysa C. A. Resende, Alexandre A. Pimenta, Maria Paulete Martins, Siomel Savio, Cristiane Godoy Targon, Guotao Yang, Jing Jiao, Chi Wang, Zhengkuan Liu |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Atmosphere, Vol 13, Iss 11, p 1867 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2073-4433 |
| DOI: |
10.3390/atmos13111867 |
| Popis: |
We analyzed the C-structures in the mesospheric metal layers. We used two datasets: one from a narrow band Sodium (Na) Density and Temperature LIDAR and the other from a high-resolution dual band Na and Potassium (K) LIDAR, both operated at São José dos Campos, Brazil (23° S, 46° W). We also investigated the Es layer occurrence and wind shear influences forming these structures. We found three C-type events over 82 analyzed nights in the first data set. They all showed lower temperatures inside C-structures compared to the borders. The squared Brunt-Väissälä frequency analyses showed positive values in the region of C-structures. In two out of three cases, dynamical instability was present (Ri < 0.25). We compared these results with the nine simultaneous C-type events identified in the 185 nights from the second data set. They showed height and time simultaneity correspondence as observed in the Na and K layers. Our results showed a low correlation between Es occurrence and C-structures. Additionally, strong wind shears in the altitude and time where C-structures appeared were always present. The advection of a metal cloud to the LIDAR station and a wind distortion seems to be the plausible mechanism that can explain all the observations. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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