Em visita ao Brasil, a Dra. Viviane Menezes, pesquisadora de Pós-Doutorado do Woods Hole Oceanographic Institution, traz ao IOUSP resultados inéditos sobre dois projetos em andamento, que investigam as interações ar-mar e a circulação oceânica de duas regiões: o Mar Vermelho e o Oceano Austral (Índico).
- 6 de dezembro de 2017, quarta-feira, às 15:00 h
Dra. Viviane Menezes, Oceanógrafa (UERJ), Mestre em Sensoriamento Remoto (INPE), PhD em Marine Science (University of Tasmania), Post-Doc Investigator do Woods Hole Oceanographic Institution (WHOI), Estados Unidos
Título: Air-sea interaction, surface water mass transformation and ocean circulation— from warm-salty (Red Sea) to cold-fresh waters (Southern Ocean)
Local: Anfiteatro do Instituto Oceanográfico – USP
Camila Signori e Marcos Tonelli
Instituto Oceanográfico, Universidade de São Paulo
Praça do Oceanográfico, 191
São Paulo-SP, Brasil 055508-120
Title: Air-sea interaction, surface water mass transformation and ocean circulation— from warm-salty (Red Sea) to cold-fresh waters (Southern Ocean)
Viviane V. Menezes (Woods Hole Oceanographic Institution)
In this talk, I will present the results of two on-going projects that investigate air-sea interactions and ocean circulation in two different regions of the global oceans: the Red Sea and the Southern Indian Ocean.
The Red Sea Overflow Water (RSOW) is one of the most saline water masses of the global oceans. It is formed in the northern Red Sea as part of the Red Sea Overturning Circulation. The RSOW is exported to the Indian Ocean and affects both adjacent and remote areas at intermediate depths. Its salty signal has been found as far as the southern tip of Africa and also off western Australia, and may even contribute to the Indo-Atlantic water exchange through Agulhas eddies, possibly being a component of the global overturning circulation. It is believed that maximum RSOW production occurs during the boreal winter as a result of intense evaporation and surface cooling, especially under extreme meteorological conditions. One of these conditions is the onset of the wintertime surface mountain-gap wind jets along the northern Red Sea eastern boundary. According to model simulations, this region is dominated by a surface poleward Eastern Boundary Current (EBC) that becomes cooler and saltier as it moves northward due to strong air-sea fluxes. In the present work, we characterize the wintertime mountain-gap wind jets and investigate their effects of on the EBC through analysis of in situ observations from a heavily instrumented WHOI air-sea interaction mooring deployed between 2008-2010, Satellite Sea Surface Temperature, QuikSCAT satellite data, and 1/12 HYCOM outputs.
Antarctic Bottom Water (AABW) is a key component of the ocean’s overturning circulation and spreads into the abyss of the major ocean basins. Changes in its properties have been shown to affect the circulation, ocean heat content, sea level, and Earth’s climate over decadal to glacial-interglacial time scales. In this study, the data collected during the third occupation of the GO-SHIP I08S hydrographic line in February-March 2016 are compared with previous observations collected in 1994 and 2007. The comparison reveals a striking accelerated freshening of AABW between 2007 and 2016 in the Australian-Antarctic Basin, which is at least four times stronger than that found in the earlier period (1994–2007). It is conjectured that this strong freshening is linked to the abrupt iceberg (B9B)-glacier (Mertz Glacier Tongue) collision and calving event that occurred in 2010 on the George V/Adélie Land Coast, an AABW source region for the Antarctic-Australian Basin.