Silvia Garzoli, Alberto Piola, Sabrina Speich, Edmo Campos Presented by: Molly Baringer The overarching goal of the SAMOC initiative is to observe and understand the mechanisms that control the mean and time-varying MOC in the South Atlantic and the interocean exchanges. SAMOC is an international cooperation between Argentina, Brazil, France, South Africa and the USA. Additional collaborators from Germany, Russia, Spain, UK Funding: NOAA, CNPq/INCT, IAI, IFREMER/ANR, DEA, … (http://www.aoml.noaa.gov/phod/SAMOC_international) SAMOC endorsed by CLIVAR SSG in May 2012 (1979 to 2008) – (1871 to 1900) Observa>ons Outside Atlan>c Fluxes Atlan>c Fluxes Heat transport and vectors Lee et al. (2011) • The NCAR CCSM3 model is forced with ﬂuxes isolated from the AtlanHc only vs. from the rest of the ocean. • Flux forcing outside the AtlanHc induces large heat advecHon south of Africa following the MOC pathway. • The South AtlanHc MOC can modulate secular and mulHdecadal warming in the AtlanHc Ocean. Transport Density Garzoli and Matano (2011) • The South AtlanHc not a passive conduit for NADW and other deep water masses. • Model analysis shows largest water mass transformaHons occur in energeHc boundary regions. • AAIW created in SW AtlanHc by surface/deep waters. • AAIW transformed into surface waters in Cape Basin. • SchemaHc of the SAMOC observing network (“the vision”) • SAMoc Basin-‐wide Array (SAMBA) along 34.5°S • Eastern boundary short/tall moorings, oblique Goodhope transect by end 2014 • Seeking funding for short/tall moorings on western boundary, interior PIES-‐datapods • Color shading: mean OFES simulaHon meridional velocity at 200 m depth • JASON ground-‐tracks are overlaid as light gray lines More details @ hGp://www.aoml.noaa.gov/phod/SAMOC_interna>onal/ • High density XBT lines used to esHmate volume/heat transport in the upper 800 m • Data collected from XBT lines contributes to SAMOC program • Lines sampled from 2 – 6 Hmes/year • In both 2012 and 2013, array doubled in size! • Eastern boundary short/tall moorings to be deployed by the end of 2014 • Seeking funding for short/tall moorings on western boundary, interior PIES-‐datapods • Gray shading: topography The mooring array oﬀ Rio Grande is designed to serve as the shelf boundary of the western boundary of the SAMOC/SAMBA array • Main regions where ﬁeld acHviHes are planned within scope of INCT-‐Mar ICO • ExisHng moorings (blue dots) • Planned moorings (black dots) ABIISS (4 datapods) • Successful launch of two data pods and data transmission via satellite from US ABIISS • 6 month test deployment in the Florida Straits (800 m) • Instrument recovery in August 2014 Instrument: IES SYREDOMY (6 Messengers) • Successful data transmission via satellite from ﬁrst set of French SYREDOMY messengers (example: SAMOC/SAMBA CPIES, 5300 m) Tau (acousHc travel Hme) Boiom pressure (5300 m) Instrument: CPIES • To assess impact of Indo-‐AtlanHc exchange on SAMOC, 7 PIES will be deployed in 2014 along oblique Goodhope transect (JASON-‐2 ground track) out to Agulhas Ridge • Red diamonds: Planned locaHon of PIES • Gray line: CLIVAR Goodhope line sampled twice/year • Color shading: RMS of AVISO Absolute Dynamic Height 0 −1000 o 56 S o 58 S −3000 o 60 S PF −4000 −5000 o 62 S SACCF o 68 W o 66 W o 64 W 62oW 60oW 58 oW • Providing a wealth of informaHon about the variability and dynamics of the ACC • Lem panel: cDrake locaHons • Right panel: Drake Passage Underway Time Series transects −6000 Depth (m) −2000 SAF 1.  Model analysis and observing system experiments 2.  Mean and intraseasonal-to-interannual variability of the MOC and 3.  4.  5.  6.  7.  8.  9.  10.  11.  12.  13.  heat and salt transport by the MOC Meridional coherence (or lack thereof) of MOC Why models don’t get the MOC seasonal cycle right? Intraseasonal-to-interannual variability/secular changes of Agulhas leakage and impact on the MOC Intraseasonal-to-interannual variability/secular changes of boundary currents (BC, DWBC…) and impact on the MOC Mean and intraseasonal-to-interannual variability of ACC transport through Drake Passage SAMOC water mass pathways (e.g., fate of NADW) Study of water mass properties on the boundaries (T, S, O2) Water mass transformations Eddy-mean flow interactions Bistability of the MOC (“MOV”) … and many more More SAMOC publica>ons @ hGp://www.aoml.noaa.gov/phod/SAMOC_interna>onal/ MOC esHmated from a daily Hme series of dynamic height from inverted echo sounders (PIES/CPIES) • An ~20 month long pilot array and a novel technique using model output and Argo data helps determine the daily MOC strength at 35°S. • MOC Hme series compares favorably with XBT derived Hme series. • MOC variability is as large at that at 26N, with both eastern and western boundary ﬂows contribuHng equally to the variance. • The full array was reestablished in the fall of 2013 in collaboraHon with France, Brazil, ArgenHna and South Africa. Meinen et al. (2013) AOML Program Review AMOC associated ﬂuxes and transports in the South Atlan>c at 35°S 0.9 26.2 0 0.8 23.9 −0.05 0.7 21.6 0.6 19.3 17 0.4 14.7 0.3 12.4 0.2 01/03 01/05 01/07 01/09 01/11 Month/Year 01/13 10.1 MOV (Sv) 0.5 −0.1 Amoc (Sv) MHT (PW) South AtlanHc XBT observaHons can esHmate MOC, heat and fresh water ﬂuxes −0.15 −0.2 −0.25 −0.3 −0.35 −0.40 01/03 01/05 01/07 01/09 Month/Year 01/11 01/13 • Meridional heat transport at 35°S in the South AtlanHc is 0.55 ± 0.14 PW, with larger variability than at 26°N. • MOC is 18.17 ± 2.3 Sv, similar in magnitude as 26°N, but with slightly lower variability. • Fresh Water ﬂuxes are less than zero, implying that the MOC is bi-‐stable. Note that numerical models have a stable MOC with a posiHve slainity ﬂux in the South AtlanHc. 14 Garzoli et al., 2013; Dong et al., 2009 AOML Program Review !  New sites/moorings: !  Short/tall moorings (T, S, p, v) on the western boundary to better measure transport (BC, DWBC) and water mass (NADW) changes !  PIES in the interior (i.e., either side of the MAR) !  Drake Passage moorings for ACC transport Pressure [ dbar ] M1−3 M4 0 a) 500 1000 1500 2000 2500 3000 M1 M2 M3 3500 4000 4500 5000 54°W 51°W M5 48°W M1−3 M4 45°W 0 b) 500 1000 1500 2000 2500 3000 M1 M2 M3 3500 4000 4500 5000 54°W 51°W M5 40 30 20 10 0 −10 −20 −30 48°W 45°W • Proposed locaHons of tall moorings on the western boundary • Shading: Mean OFES (lem) and NEMO (right) meridional velocity along 34.5°S −40 Meridional Velocity [ cm s−1 ] !  Trans-basin hydrographic/SADCP/tracer cruise !  Challenges: Funding, Ship time (cruises by international partners) Optimizing and Enhancing the Integrated Atlantic Ocean Observing System AtlantOS is a project responding to the Horizon 2020 call BG-‐8-‐2014: Developing in-‐situ AtlanHc Ocean ObservaHons for a beier management and sustainable exploitaHon of the mariHme resources. It proposes the integraHon of ocean observing acHvates across all disciplines for the AtlanHc, considering European as well as non-‐European partners (referencing to "The Galway Statement on AtlanHc Ocean CooperaHon", May 2013). The proposal applies the "Framework for Ocean Observing" to the observing of the AtlanHc. The overarching goal of AtlantOS is the integraHon of the so far loosely-‐ coordinated set of exisHng ocean observing acHviHes to a sustainable, eﬃcient, and ﬁt-‐for-‐purpose Integrated AtlanHc Ocean Observing System (IAOOS). The IAOOS is to form the ocean in-‐situ observing backbone of the Copernicus Marine Monitoring system, which is the marine part of the European Earth ObservaHon Programme. Structure of AtlantOS