Characterization of moisture sources for austral seas and relationship with sea ice concentration

• Published in: Atmosphere
• Main Authors: Reboita, Michelle Simões, Nieto Muñiz, Raquel Olalla, Rocha, Rosmeri Porfírio da, Rodrigues De Moraes Drumond, Anita, Vázquez Domínguez, Marta, Gimeno Presa, Luis
• Format: Article in Journal/Newspaper
• Language: English
• Published: Atmosphere 2019
• Subjects: 25 Ciencias de la Tierra y del Espacio; 2501 Ciencias de la Atmósfera; 2501.06 Dinámica Atmosférica; 2502 Climatología; Antarctic; Southern Ocean; Weddell Sea; Austral; Weddell; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/11093/2124; https://doi.org/10.3390/atmos10100627; https://www.mdpi.com/2073-4433/10/10/627

In this study, the moisture sources acting over each sea (Weddell, King Haakon VII, East Antarctic, Amundsen-Bellingshausen, and Ross-Amundsen) of the Southern Ocean during 1980–2015 are identified with the FLEXPART Lagrangian model and by using two approaches: backward and forward analyses. Backward analysis provides the moisture sources (positive values of Evaporation minus Precipitation, E − P > 0), while forward analysis identifies the moisture sinks (E − P < 0). The most important moisture sources for the austral seas come from midlatitude storm tracks, reaching a maximum between austral winter and spring. The maximum in moisture sinks, in general, occurs in austral end-summer/autumn. There is a negative correlation (higher with 2-months lagged) between moisture sink and sea ice concentration (SIC), indicating that an increase in the moisture sink can be associated with the decrease in the SIC. This correlation is investigated by focusing on extremes (high and low) of the moisture sink over the Weddell Sea. Periods of high (low) moisture sinks show changes in the atmospheric circulation with a consequent positive (negative) temperature anomaly contributing to decreasing (increasing) the SIC over the Weddell Sea. This study also suggests possible relationships between the positive (negative) phase of the Southern Annular Mode with the increase (decrease) in the moisture that travels from the midlatitude sources to the Weddell Sea. Fundação de Amparo à Pesquisa do Estado de São Paulo | Ref. 2017/03981-3 Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil) | Ref. 304949/2018-3 Xunta de Galicia | Ref. ED481B 2018/062 Xunta de Galicia | Ref. Ref. ED413C 2017/64 European Commission