Sea surface temperature anomalies driven by oceanic local forcing in the Brazil-Malvinas Confluence

Author(s)

da Silveira, Isabel Porto ^{[1, 2]} ; Pezzi, Luciano Ponzi ^{[1, 3]}

Affiliation

^[1] Natl Inst Space Res INPE, SERE 2, BR-12227010 Sao Jose Dos Campos, SP - Brazil

^[2] Ctr Weather Forecast & Climate Studies CPTEC, BR-12227010 Sao Jose Dos Campos - Brazil

^[3] Earth Observat Gen Coordinat OBT, BR-12227010 Sao Jose Dos Campos - Brazil

• Document type: Journal article
• Source: OCEAN DYNAMICS; v. 64, n. 3, p. 347-360, MAR 2014.
• Web of Science Citations: 0

Abstract

Sea surface temperature (SST) anomaly events in the Brazil-Malvinas Confluence (BMC) were investigated through wavelet analysis and numerical modeling. Wavelet analysis was applied to recognize the main spectral signals of SST anomaly events in the BMC and in the Drake Passage as a first attempt to link middle and high latitudes. The numerical modeling approach was used to clarify the local oceanic dynamics that drive these anomalies. Wavelet analysis pointed to the 8-12-year band as the most energetic band representing remote forcing between high to middle latitudes. Other frequencies observed in the BMC wavelet analysis indicate that part of its variability could also be forced by low-latitude events, such as El Nio. Numerical experiments carried out for the years of 1964 and 1992 (cold and warm El Nio-Southern Oscillation (ENSO) phases) revealed two distinct behaviors that produced negative and positive sea surface temperature anomalies on the BMC region. The first behavior is caused by northward cold flow, Rio de la Plata runoff, and upwelling processes. The second behavior is driven by a southward excursion of the Brazil Current (BC) front, alterations in Rio de la Plata discharge rates, and most likely by air-sea interactions. Both episodes are characterized by uncoupled behavior between the surface and deeper layers. (AU)

• FAPESP's process: 07/06782-0 - The oceanic and atmospheric anomalies study over the Brazil-Malvinas Confluence region
• Grantee: Isabel Porto da Silveira
• Support Opportunities: Scholarships in Brazil - Master