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Meinen, Christopher S.; Speich, Sabrina; Piola, Alberto R.; Ansorge, Isabelle; Campos, Edmo; Kersale, Marion; Terre Terrillon, Thierry; Chidichimo, Maria Paz; Lamont, Tarron; Sato, Olga T.; Perez, Renellys C.; Valla, Daniel; Van Den Berg, Marcel; Le Henaff, Matthieu; Dong, Shenfu; Garzoli, Silvia L.. |
Six years of simultaneous moored observations near the western and eastern boundaries of the South Atlantic are combined with satellite winds to produce a daily time series of the basin-wide meridional overturning circulation (MOC) volume transport at 34.5 degrees S. The results demonstrate that barotropic and baroclinic signals at both boundaries cause significant transport variations, and as such must be concurrently observed. The data, spanning similar to 20 months during 2009-2010 and similar to 4 years during 2013-2017, reveal a highly energetic MOC record with a temporal standard deviation of 8.3 Sv, and strong variations at time scales ranging from a few days to years (peak-to-peak range = 54.6 Sv). Seasonal transport variations are found to have... |
Tipo: Text |
Palavras-chave: Meridional overturning circulation; South Atlantic; Overturning; Volume transport; Observations. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55612/57253.pdf |
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Meinen, Christopher S.; Speich, Sabrina; Perez, Renellys C.; Dong, Shenfu; Piola, Alberto R.; Garzoli, Silvia L.; Gladyshev, Sergey; Baringer, Molly; Campos, Edmo J. D.. |
Data from two boundary arrays deployed along 34.5°S are combined to produce the first continuous in situ time series observations of the basin-wide meridional overturning circulation (MOC) in the South Atlantic. Daily estimates of the MOC between March 2009 and December 2010 range between 3 Sv and 39 Sv (1 Sv = 106 m3 s−1) after a 10 day low-pass filter is applied. Much of the variability in this ∼20 month record occurs at periods shorter than 100 days. Approximately two-thirds of the MOC variability is due to changes in the geostrophic (baroclinic plus barotropic) volume transport, with the remainder associated with the direct wind-forced Ekman transport. When low-pass filtered to match previously published analyses in the North Atlantic, the observed... |
Tipo: Text |
Palavras-chave: Meridional overturning circulation; Transport; South Atlantic; Inverted echo sounder; Bottom pressure. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00167/27789/25982.pdf |
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Artana, Camila; Ferrari, Ramiro; Koenig, Zoe; Sennechael, Nathalie; Saraceno, Martin; Piola, Alberto R.; Provost, Christine. |
We combined altimetric data and the in situ data sets from three 10 years apart mooring deployments to compute a coherent and accurate volume transport time series of the Malvinas Current (MC) at 41 degrees S. We used a method developed in Koenig et al. (2014) and explored three types of geostrophic shear to estimate the uncertainty derived from the lack of velocity data in the upper 300 m. The mean MC transport over 24 years in the upper 1,500 m is 37.12.6 Sv and the standard deviation 6.61 Sv. Since 1993, annual mean transports have varied from 32 to 41 Sv and the three in situ records corresponded to low annual mean transports. The MC transport time series is not stationary, its spectral content evolves with time showing significant energy at the 30-110... |
Tipo: Text |
Palavras-chave: Malvinas Current; Transport; Time series; Altimetry; Moorings; Argentine Basin. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00481/59315/62076.pdf |
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Campos, Marilia C.; Chiessi, Cristiano M.; Voigt, Ines; Piola, Alberto R.; Kuhnert, Henning; Mulitza, Stefan. |
Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (delta C-13), i.e. delta(CO2atm)-C-13, presumably due to out-gassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present delta C-13 records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1%) during Heinrich Stadials 3 and 2. These delta C-13 decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent... |
Tipo: Text |
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Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53162/55294.pdf |
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Hofmann, Eileen; Bundy, Alida; Drinkwater, Ken; Piola, Alberto R.; Avril, Bernard; Robinson, Carol; Murphy, Eugene; Maddison, Lisa; Svendsen, Einar; Hall, Julie; Xu, Yi. |
The Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) project aims at developing a comprehensive understanding of and accurate predictive capacity of ocean responses to accelerating global change and the consequent effects on the Earth system and human society. Understanding the changing ecology and biogeochemistry of marine ecosystems and their sensitivity and resilience to multiple drivers, pressures and stressors is critical to developing responses that will help reduce the vulnerability of marine-dependent human communities. This overview of the IMBER project provides a synthesis of project achievements and highlights the value of collaborative, interdisciplinary, integrated research approaches as developed and implemented through IMBER... |
Tipo: Text |
Palavras-chave: IMBER; Global environmental change; Marine ecosystems; Biogeochemical cycles; Human systems; Marine sustainability. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00383/49441/49932.pdf |
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Ansorge, Isabelle J.; Baringer, Molly; Campos, Edmo J.d.; Dong, S.; Fine, R.a.; Garzoli, Silvia L.; Goni, Gustavo; Meinen, Christopher S.; Perez, R.c.; Piola, Alberto R.; Roberts, M.j.; Speich, Sabrina; Sprintall, J.; Terre Terrillon, Thierry; Van Den Berg, M.a.. |
The meridional overturning circulation (MOC) is a global system of surface, intermediate, and deep ocean currents. The MOC connects the surface layer of the ocean and the atmosphere with the huge reservoir of the deep sea and is the primary mechanism for transporting heat, freshwater, and carbon between ocean basins. Climate models show that past changes in the strength of the MOC were linked to historical climate variations. Further research suggests that the MOC will continue to modulate climate change scenarios on time scales ranging from decades to centuries [Latif et al., 2006]. |
Tipo: Text |
Palavras-chave: South Atlantic; Meridional Overturning Circulation; CPIES. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28609/27109.pdf |
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