The high-frequency variability of Antarctic sea ice and polar cold air incursions over Amazonia

Autor(es)

Bertoletti Carpenedo, Camila ^[1] ; Pereira Silveira Campos, Jose Leandro ^[2] ; Ambrizzi, Tercio ^[2] ; Burgo Braga, Ricardo ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Parana, Sect Agr Sci, Dept Soils & Agr Engn, Curitiba, Parana - Brazil

^[2] Univ Sao Paulo, Dept Atmospher Sci, Inst Astron Geophys & Atmospher Sci, Sao Paulo, SP - Brazil

^[3] INNTI Environm Consulting & Agr, Projects Dept, Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF CLIMATOLOGY; NOV 2021.
• Citações Web of Science: 0

Resumo

The cold air incursion over South America is associated with the frontal systems generated in the Antarctic region, and sea ice cover plays an important role in its formation. Little is known about how the high-frequency variability of the coupled ocean-cryosphere-atmosphere system affects weather conditions in South America, especially in the Amazon region - in tandem with the largest tropical forest on the planet and a key region of the global climate system. The results presented here suggest that the high-frequency variability of the expansion of Antarctic sea ice extent (SIE) extremes, in the Ross Sea and Indian Ocean, modulate the cold air incursion over the Amazon in the southern winter 4 and 2 days after the expansion of SIE extremes, respectively. The SIE extremes can couple with the atmosphere, inducing Rossby waves that propagate and undergo amplification downstream from the Ross Sea and Indian Ocean during such extremes. In this way, the atmospheric wave train acquires a more southern spread over South America, reaching tropical latitudes after the SIE extremes. In non-SIE extreme periods, the atmospheric wave train has a more zonal spread and reaches only the extratropical latitudes of the continent. (AU)

• Processo FAPESP: 14/50848-9 - INCT 2014: INCT para Mudanças Climáticas (INCT-MC)
• Beneficiário: Jose Antonio Marengo Orsini
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 17/09659-6 - Variabilidade interanual dos transportes meridionais através da rede transatlântica SAMOC (SAMBAR)
• Beneficiário: Edmo José Dias Campos
• Modalidade de apoio: Auxílio à Pesquisa - Temático