Characterization of Moisture Sources for Austral Seas and Relationship with Sea Ice Concentration

Author(s)

Reboita, Michelle Simoes ^[1] ; Nieto, Raquel ^[2] ; da Rocha, Rosmeri P. ^[3] ; Drumond, Anita ^[4] ; Vazquez, Marta ^{[5, 2]} ; Gimeno, Luis ^[2]

Affiliation

^[1] Univ Fed Itajuba, Inst Recursos Nat, BR-37500903 Itajuba, MG - Brazil

^[2] Univ Vigo, Environm Phys Lab EPhysLab, CIM UVigo, Orense 32004 - Spain

^[3] Univ Sao Paulo, Dept Ciencias Atmosfer, BR-05508090 Sao Paulo, SP - Brazil

^[4] Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09913030 Diadema - Brazil

^[5] Univ Lisbon, Inst Dom Luiz, P-1749016 Lisbon - Portugal

• Document type: Journal article
• Source: ATMOSPHERE; v. 10, n. 10 OCT 2019.
• Web of Science Citations: 0

Abstract

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. (AU)

• FAPESP's process: 17/03981-3 - Atmospheric moisture transport, the bridge between ocean evaporation and Antarctic sea ice
• Grantee: Rosmeri Porfírio da Rocha
• Support Opportunities: Research Grants - Visiting Researcher Grant - International