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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Sea ice in the Weddell Sea and its relationship with the South Atlantic Subtropical High and precipitation in South America

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Author(s):
CAMILA B. CARPENEDO [1] ; TÉRCIO AMBRIZZI [2] ; RAFAEL CESAR SILVA [3]
Total Authors: 3
Affiliation:
[1] Universidade Federal do Paraná. Departamento de Solos e Engenharia Agrícola - Brasil
[2] Universidade de São Paulo. Instituto de Astronomia - Brasil
[3] Universidade Federal do Rio Grande do Sul. Programa de Pós-Graduação em Geografia - Brasil
Total Affiliations: 3
Document type: Journal article
Source: Anais da Academia Brasileira de Ciências; v. 94, 2022-10-21.
Abstract

Abstract This study aims to evaluate the position and intensity of the South Atlantic Subtropical High (SASH), related to sea ice extent (SIE) retraction and expansion in the Weddell Sea, assessing precipitation in South America. We assess the difference between atmospheric fields related to SIE (four most intense retraction events minus four most intense expansion events) in February. To this end, we used NSIDC SIE, ERA-5 reanalysis, CHIRPS precipitation, ICOADS SST, ONI/SAM indexes (CPC/NOAA). In the following month, under neutral ENSO and SAM, we observed tropospheric warming in the Weddell Sea and cooling in the mid-latitudes South Atlantic. There is a weakening of both the Weddell Sea circumpolar low and the high pressures between tropical and subtropical latitudes, in addition to the equatorward shift of the Ferrel cell. Therefore, SASH weakens and contracts, resulting in a reduction of the tropical Atlantic moisture supply to South America and negative precipitation anomalies in the tropical region - similar to the suppression pattern of the South Atlantic Convergence Zone. Our results suggest that SIE retraction (expansion) in the Weddell Sea may contribute to the weakening (strengthening) of the SASH and an early-ending (longer-ending) or drier-ending (wetter-ending) rainy season in tropical South America. (AU)

FAPESP's process: 17/09659-6 - Interannual variability of the meridional transports across the SAMOC basin-wide array (SAMBAR)
Grantee:Edmo José Dias Campos
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 14/50848-9 - INCT 2014: INCT for Climate Change
Grantee:Jose Antonio Marengo Orsini
Support Opportunities: Research Program on Global Climate Change - Thematic Grants