CLIVAR Atlantic Implementation Panel Peter Brandt (co-Chair) IfM-GEOMAR, Kiel Laurent Terray (co-Chair) CERFACS, France Molly Baringer NOAA/AOML, USA Suzana Camargo LDEO, USA Ping Chang Texas A&M, USA Ruth Curry WHOI, USA Tom Farrar WHOI, USA Bogi Hansen FMRI, Faroe Islands Yochanan Kushnir LDEO, USA Mauricio Mata FURG Brazil Mathieu Rouault Univ. Cape Town, South Africa Doug Smith Hadley Centre, UK Anne-Marie Treguier IFREMER, France ICPO Contact: Nico Caltabiano

CLIVAR AIP Recent activities Basin focus: supporting CLIVAR science with sustained observations and research on climate variability and predictability SAMOC III meeting, Rio de Janeiro/Niteroi, Brazil, May 2010 US AMOC Meeting (7-9 June 2010, Miami, FL, USA)US AMOC Meeting (7-9 June 2010, Miami, FL, USA) Decadal Variability, Predictability and Prediction: Understanding the role of the Ocean ( Sep 2010) – Boulder (WGOMD/GSOP)Decadal Variability, Predictability and Prediction: Understanding the role of the Ocean ( Sep 2010) – Boulder (WGOMD/GSOP) AIP/VAMOS Workshop on Coupled Ocean-Atmosphere-Land Processes in the Tropical Atlantic, Miami, FL, USA, March th AIP meeting, Miami, FL, USA, March 2011 Rapid-US AMOC international conference, Bristol, U.K, July 2011Rapid-US AMOC international conference, Bristol, U.K, July 2011 Contribution to several sessions for WCRP OSC (24-28 October 2011, Denver, USA)Contribution to several sessions for WCRP OSC (24-28 October 2011, Denver, USA)

CLIVAR AIP: Near-term issues and challenges Current state and evolution of the Atlantic ocean observing system MOC observational system: Encourage completion of trans-basin monitoring system for the time-varying strength of the AMOC at other latitudes than 26.5°N (subpolar North Atlantic and subtropical South Atlantic). Assess the meridional coherence of AMOC changes and provide strong constraint on climate models and synthesis products.MOC observational system: Encourage completion of trans-basin monitoring system for the time-varying strength of the AMOC at other latitudes than 26.5°N (subpolar North Atlantic and subtropical South Atlantic). Assess the meridional coherence of AMOC changes and provide strong constraint on climate models and synthesis products. THOR ending in 2012: THOR built on, maintained and completed previous efforts within the subpolar gyre: time series observation of fluxes and properties span decades at many sites. Funding is running out next year both for THOR and non-THOR activities. Continuation might be possible (EU + German funding + coordination effort with OSNAP needed)THOR ending in 2012: THOR built on, maintained and completed previous efforts within the subpolar gyre: time series observation of fluxes and properties span decades at many sites. Funding is running out next year both for THOR and non-THOR activities. Continuation might be possible (EU + German funding + coordination effort with OSNAP needed) TACE Ending: need for a synthesis product allowing an optimal use of existing data sets for model-data comparison (high-res CORE forcing simulations)TACE Ending: need for a synthesis product allowing an optimal use of existing data sets for model-data comparison (high-res CORE forcing simulations) PIRATA: Keep trying to find funding to maintain the South East extension (need to buy one additional mooring, include radiometers)PIRATA: Keep trying to find funding to maintain the South East extension (need to buy one additional mooring, include radiometers) Lack of deep ocean measurements: Encourage community action to address this gap, support of OOPC recommendationsLack of deep ocean measurements: Encourage community action to address this gap, support of OOPC recommendations

WORKSHOP ON COUPLED OCEAN‐ATMOSPHERE‐LAND PROCESSES IN THE TROPICAL ATLANTIC. Miami, FL, March 23-25, 2011 (with WCRP and US agencies support) Meeting Objectives 1. Develop a coherent synthesis of the state-of-the-art knowledge on Atlantic biases and their causes for the southeast and eastern tropical Atlantic and further sharpen hypotheses 2. Articulate an effective way forward 3. Identify an international network of interested, active researchers 4. Define an appropriate geographical focus or foci 1. Enthusiasm high (85 registered participants, all the talks on the CLIVAR web page) 2. UK, US and French atmospheric scientists (NERC,Met Office, VOCALS, NASA, CNRM) motivated to invest in southeast Atlantic b/c of biomass-burning aerosol and low cloud. 3. On going discussion on the ocean side on process study interest and feasibility (upwelling, wind-sst feedbacks, role of ocean eddies, biogeochemistry), regional modeling studies 4. On going writing of a ‘task team’ proposal to assemble a working group (across WCRP) to address #1 and #2, a nested two-tier geographic focus suggested, with inner tier bounded by ~ 25W-15E, 25S-5N. Meeting Assessment CLIVAR AIP: Near-term issues and challenges

Model and ocean synthesis data analysis Diagnostic subprojects within the group to look at various model simulations and synthesis products CMIP5 Ocean and atmosphere outputs with a focus on decadal hindcasts and 20C3M simulations (observed ocean sections, surface salinity, heat content, meridional and zonal Atlantic modes). Analyze predictability and model biases. Assess whether ocean synthesis products are able to reproduce recent interannual to decadal variability in the Atlantic Question: what would be the future role of basin panels ? Where is the interface with the other panels ?

Interannual SST and atmospheric variability forced by equatorial Atlantic Ocean deep jets Brandt et al. 2011, Nature

© Crown copyright Met Office Skill in tropical Atlantic atmosphere in idealised experiments Dunstone et al, 2011, submitted Large set of idealised model experiments (>25 start dates) Monthly mean T & S ocean data is assimilated at all model locations (no atmosphere assimilation) Stippled regions are significant at the 5% level Blue box shows the main hurricane development region (MDR) JJASON seasons, Forecast years 2-6: temperature zonal wind shear precipitation MSLP

Skill originates from sub-polar gyre Dunstone et al, 2011, submitted precipitation wind shear