Spatial fields of Antarctic sea-ice concentration anomalies for summer–autumn and their relationship to Southern Hemisphere atmospheric circulation during the period 1979–2009

• Autores: Barreira, Sandra; Compagnucci, Rosa Hilda
• Año de publicación: 2011
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Period 1979–2009; Sica; Pca
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Summer–autumn monthly sea-ice concentration anomaly (SICA) fields in Antarctica obtained from satellite data for the period 1979–2009 were analysed with Varimax-rotated T-mode principal component analysis (PCA). The first three PCA scores described the SICA spatial behaviour and explained 38.07% of the total variance. The related atmospheric circulation characteristics were analysed using 850 hPa height and surface air-temperature anomalies for the months clustered by the corresponding SICA composites, which were based on PCA loadings above a ±0.3 threshold. The principal characteristics of SICA can be seen between the Ross and Weddell Seas, areas that remained ice-covered during the analysis period. Elsewhere around Antarctica, small distinct characteristics occur mostly in embayments. The leading summer–autumn SICA pattern shows a structure with two centres of equal sign located one over the Weddell and the other over the Ross Sea–southwest Pacific Ocean sector and a centre of opposite sign over the Bellingshausen and Amundsen Seas. The second SICA pattern is represented by a dipole over the Weddell Sea as a result of an increase (decrease) in sea-ice concentration in the northern sector (positive phase) and a decrease (increase) in the southern region, together with a positive (negative) centre over the Ross and Amundsen Seas. The latter pattern is characterized by equal-sign anomalies on both sides of the Antarctic Peninsula and opposite-sign centres all around Antarctica with the highest intensity over the Ross Sea.
Fil: Barreira, Sandra. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento de Metereologia; Argentina
Fil: Compagnucci, Rosa Hilda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina