Analysis of significant stratospheric ozone reductions over southern Brazil: A proposal for a diagnostic index for southern South America

Meteorological applications

article

Gustavo Rasera¹  Vagner Anabor¹  Luiz Angelo Steffenel³  Damaris Kirsch Pinheiro⁴  Franciano Scremin Puhales¹  Lissette Guzmán Rodríguez¹  Lucas Vaz Peres⁶ 

[1] Department of Physics, Universidade Federal de Santa Maria;Contribution: Conceptualization;Université de Reims Champagne Ardenne, Laboratoire LICIIS/LRC CEA DIGIT;Department of Chemical Engineering, Universidade Federal de Santa Maria;Contribution: ​Investigation;Institute of Engineering and Geosciences, Universidade Federal do Oeste do Pará;Contribution: Writing - original draft

关键词: forecasting;    index;    isentropic analysis;    ozone;    statistical methods;    stratosphere;   

DOI  :  10.1002/met.2034

学科分类：社会科学、人文和艺术（综合）

来源: Wiley

【 摘 要 】

During the southern spring, a break of the polar vortex over the Antarctic continent frequently occurs. This results in the advection of ozone-poor air mass (O 3 ) to mid-latitudes, characterizing the secondary effect of the Antarctic ozone hole (SEAOH). We present some distinct characteristics the eight greatest reductions of the total O 3 column (TOC) over the central region of Rio Grande do Sul (RS, 29.5°S, 54°W), southern Brazil, between August and November from 2012 to 2016 and develop a full scalar diagnostic index of O 3 negative anomalies for South America. For developing the index, mean values of the absolute potential vorticity, geopotential height, and wind components were obtained over moving grids with positive and negative O 3 anomalies. It was then possible to develop statistical methods to obtain a diagnostic index of the SEAOH (Subantarctic O 3 Index), as well as a diagnostic index of incursions of ozone-poor air masses from the tropics (Subtropical O 3 Index). The results show that TOC over the central region of RS, for the most intense O 3 reduction episodes, is governed by a wide range of contributions from high and low isentropic levels. Significant interaction of air masses of polar and tropical origin via stratosphere–troposphere exchange was found. Finally, the Subantarctic O 3 Index combined with the Subtropical O 3 Index showed potential use for prediction centres and was skilful in detecting regions with the most negative O 3 anomalies, mainly in the mid-latitude region, but also in the subtropical region.

【 授权许可】

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