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Environmental monitoring is crucial to our understanding of climate change, biodiversity loss and pollution. The availability of large-scale spatio-temporal data from sources such as sensors and satellites allows us to develop sophisticated models for forecasting and understanding key drivers. However, the data collected from sensors often contain missing values due to faulty equipment or maintenance issues. The missing values rarely occur simultaneously leading to data that are multivariate misaligned sparse time series. We propose two models that are capable of performing multivariate spatio-temporal forecasting while handling missing data naturally without the need for imputation. The first model is a transformer-based model, which we name SERT (Spatio-temporal Encoder Representations from Transformers). The second is a simpler model named SST-ANN (Sparse Spatio-Temporal Artificial Neural Network) which is capable of providing interpretable results. We conduct extensive experiments on two different datasets for multivariate spatio-temporal forecasting and show that our models have competitive or superior performance to those at the state-of-the-art., 11 pages, 7 figures

In 1842, as part of the first land survey of Ireland, sea level observations were taken at 22 sites for durations of around six weeks and published by the astronomer royal, George Biddell Airy. While such short records could be dismissed in more sea-level data-rich countries, Ireland has sparse and geographically-biased records and these short records have proved very valuable in reconstructing the patterns and magnitudes of regional sea level change. In this paper, we discuss the adjustments for intermediate datum redefinitions, corrections for atmospheric, seasonal, and tidal effects, including validations of all of these adjustments for the determination of accurate mean sea levels from short records. These measured changes are interpreted in terms of glacial isostatic adjustment (GIA), shedding light on the recent GIA modelling of the British-Irish ice sheet. Finally, we reflect on the utility of short sea level records in the understanding of regional, climate change-driven, sea-level change and the necessary constituents in this instance., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The Atlantic Meridional Overturning Circulation (AMOC) plays a vital role in global climate, redistributing heat, freshwater and anthropogenic CO2(Canth) meridionally and in depth. Accurately monitoring AMOC strength with observations has inspired a number of dedicated observing systems in the Atlantic since the 2000s. However, no consensus has been reached on whether the slowdown of the AMOC and its associated heat, freshwater and Canthtransports is occurring. Hydrographic data and biogeochemical measurements from zonal sections across the Atlantic for 30 years that predate and overlap the era of AMOC observations were employed to build three inverse models, one for each of the last decades. The results show no changes in the AMOC for all sections analyzed over the whole Atlantic for the last 30 years.The change in time in the net transports of Canthappears to be mainly due to modifications in the transport of upper layers. The lower layer of the AMOC maintain more consistent transports intime.Verticaladvection plays an important role in the North Atlantic, exporting Canthfrom upper to deeper layers. The strong gradient in Canthconcentration at the interphase between upper and deeper layers results in a strong vertical diffusion., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Weekly to monthly regional mean sea-level fluctuations on the shelf northwest of Europe reach several tens of centimetres from peak to peak. They feature at the coast and are non-negligible component of extreme coastal sea levels in Europe, despite their subinertial periodicity and broad spatial scale. A greater understanding of their spatio-temporal scales and their drivers is critical to the understanding of extreme sea levels at the O(10cm) scale.In particular, the common mode of European mean sea level, which explains a substantial fraction of the weekly mean sea-level variability, has been hypothesized to reflect the strength of the European slope current (Chafik et al., 2017). This circulation is a wind and density driven quasi-barotropic circulation (Huthnance et al., 2020). We present substantial evidence based on in-situ current measurements that, indeed, European sea levels covary with along-isobath currents, although above shallower depths (150-400m m of water depth) relative to where the density-driven slope current is believed to flow. We discuss how these elevated (or depressed) sea levels can be driven and maintained through the joint effect of winds and bathymetry.Chafik, L., Nilsen, J. E. Ø., & Dangendorf, S. (2017). Impact of North Atlantic teleconnection patterns on Northern European sea level. Journal of Marine Science and Engineering, 5(3), 43.Huthnance, J. M., Inall, M. E., & Fraser, N. J. (2020). Oceanic density/pressure gradients and slope currents. Journal of Physical Oceanography, 50(6), 1643-1654., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The Atlantic Meridional Overturning Circulation (AMOC) is a crucial mechanism of poleward heat transport in the ocean and climate system. It plays a vital role in the redistribution ofheat and carbon in the Northern Hemisphere. Its state is linked to a number of physical factors, including sea level. Along the eastern seaboard of North America, on long timescales, the imprint of the AMOC is projected onto sea level patterns. Unlike direct observations of the AMOC, long observed timeseries of sea level do exist along this coast. Here, these observation sea level patterns are used as a bench mark for evaluation of climate model simulations, with particular focus on associated AMOC changes.A key question in AMOC science is whether climate models and observations of AMOC in the 20thcentury are consistent.If the results show they are not, this could highlight a bias in projected long-term climate projections in the 21stcentury.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

We propose a Bayesian, noisy-input, spatial-temporal generalised additive model to examine regional relative sea-level (RSL) changes over time. The model provides probabilistic estimates of component drivers of regional RSL change via the combination of a univariate spline capturing a common regional signal over time, random slopes and intercepts capturing site-specific (local), long-term linear trends and a spatial-temporal spline capturing residual, non-linear, local variations. Proxy and instrumental records of RSL and corresponding measurement errors inform the model and a noisy-input method accounts for proxy temporal uncertainties. Results focus on the decomposition of RSL over the past 3000 years along the Atlantic coast of North America.

Turbidity is commonly monitored as an important water quality index. Human activities, such as dredging and dumping operations, can disrupt turbidity levels and should be monitored and analyzed for possible effects. In this paper, we model the variations of turbidity in Dublin Bay over space and time to investigate the effects of dumping and dredging while controlling for the effect of wind speed as a common atmospheric effect. We develop a novel Vector Auto-Regressive Conditional Heteroskedasticity (VARCH) approach to modelling the dynamical behaviour of turbidity over different locations and at different water depths. We use daily values of turbidity during the years 2017-2018 to fit the model. We show that the results of our fitted model are in line with the observed data and that the uncertainties, measured through Bayesian credible intervals, are well calibrated. Furthermore, we show that the daily effects of dredging and dumping on turbidity are negligible in comparison to that of wind speed., 11 pages, 9 figures

Poster.-- Atlantic overturning: new observations and challenges, Scientific discussion meeting, 05 - 06 December 2022, London, On top of the global sampling efforts carried out since the 1990s under WOCE and GOSHIP programs, the AMOC is being monitored with several mooring arrays in key latitudes. However, the earlier results date back to the year 2000, so these mooring arrays cannot address longer-term decadal changes in the Atlantic Ocean. In contrast, hydrographic data offers the opportunity to understand this longer-term subsurface variability. To address this issue, we have carried out three inverse models in a neutral density framework, one for each of the last three decades (1990-99, 2000-09 and 2010-19). We have used hydrographic data for the entire Atlantic Ocean, covering the whole latitudinal extent of the Atlantic (Figure 1). Answering the question of the slowing of the AMOC is very important, and the contrasting results between in situ observations and model reconstructions is a significant contribution to the debate.

Additional file 1. Participant Questionnaire.

Additional file 3: Table S2. Health Service Utilisation in the last 12 months (n=174) a.

These four presentations have been the core of the side event to the All-Atlantic 2021 conference "Atlantic Pole to Pole: Climate Science 2 Policy" held on 2nd June 2021, as an online event. The side event was organised by four Horizon 2020 projects: Blue-Action, MISSION ATLANTIC, SO-CHIC and TRIATLAS. The recording of the entire event is also available here below. The policy briefing linked to this side event is available here: https://zenodo.org/record/4889819 We would like to thank once again all the participants!

Ocean circulation redistributes heat, freshwater, carbon, and nutrients all around the globe. Because of their importance in regulating climate, weather, extreme events, sea level, fisheries, and ecosystems, large-scale ocean currents should be monitored continuously. The Atlantic is unique as the only ocean basin where heat is, on average, transported northward in both hemispheres as part of the Atlantic Meridional Overturning Circulation (AMOC). The largely unrestricted connection with the Arctic and Southern Oceans allows ocean currents to exchange heat, freshwater, and other properties with polar latitudes.

Observational oceanographers are integral to the Blue‑Action consortium. The Blue-Action project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 727852. The consortium has provided coordinated feedback in the attached document, with inputs on the following: -Sustainability of Ocean observations; -Planning and sharing: planning of observations, data sharing and compliance with FAIR guidelines; -Maximising the Ocean Data.

The Atlantic Heat Conveyor or Atlantic Meridional Overturning Circulation (AMOC) is a major factor in maintenance of the climate and marine environment of the UK. The AMOC is predicted to weaken in the coming century due to climate change. The AMOC is currently in a weakened state and the subpolar North Atlantic appears to be entering a cool (and fresh) state. However, record cold temperatures in 2015 were found to be driven largely by air–sea heat loss rather than reduced AMOC. Large biogeographical and climatic shifts are expected in response to this shift to cooler conditions. There is little support for the idea that the AMOC will abruptly shut down despite new ideas suggesting more plausible mechanisms related to a shutdown. Skill in predicting climate on decadal timescales can be derived from correct initialisation of AMOC in prediction systems hence increasing the capacity to manage, mitigate, and adapt to AMOC related climate changes.

This poster presents shortly how Blue-Action contributes tothe BluePrint for Ocean Observing in the Atlantic. The poster was presented at OceanObs'2019 by Steffen Olsen (DMI). Blue-Action contributes to defining the future Atlantic monitoring system by: optimizing the monitoring systems at the gateways to the Arctic, assessing and enhancing the usefulness of the North Atlantic ocean observations in decadal prediction systems, demonstrating the value of initialized decadal predictions in climate services &nbsp

Gerard McCarthy IAPSO Early Career medal talk entitled 'Overturning Variability with Observations'

Additional file 1. SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents.

About this document Deliverable: D6.1 First Joint workshop to (re)formulate open research questions of joint interest: “Tipping Elements in the Climate System, with a Focus on the North Atlantic” Work package in charge: WP6 Clustering Actual delivery date for this deliverable: Project-month 13 Dissemination level: The general public (PU) Lead author:Natural Environment Research Council, National Oceanography Centre (NOC): Gerard McCarthy Other contributing author:Danish Meteorological Institute (DMI): Chiara Bearzotti Summary for publication The first joint workshop on areas of common interest was held on 18-19 September 2017 at Wolfson College, Oxford (UK). The focus of the workshop was tipping elements in the climate system, with a focus on the North Atlantic. Blue-Action is focused on Arctic and high latitude changes. Therefore, the high number of tipping elements in this region and their potentially large impact on Northern Hemisphere climate is of particular interest and concern to Blue-Action scientists. The workshop was organised by the Blue-Action project to link Blue-Action scientists with experts outside the project. Key areas of research and actions for future collaboration were identified.

The circulation system of the North Atlantic Ocean has weakened and is predicted to weaken further in the coming decades. An analysis suggests that this decline could lead to accelerated global surface warming. See Letter p.387

Kick off for Blue Action Project. Overview of Work Package 2 objectives.

• The AMOC is key to maintaining the mild climate of the UK. • The AMOC is predicted to decline in the 21st century in response to a changing climate. • Past abrupt changes in the AMOC have had dramatic climate consequences. • There is growing evidence that the AMOC has been declining for at least a decade, pushing the Atlantic Multidecadal Variability into a cool phase. • Short term fluctuations in the AMOC have proved to have unexpected impacts, including being linked with severe winters and abrupt sea-level rise.

Myanmar is undergoing a comprehensive political transition. In April this year the first democratically elected government in six decades came into power under the leadership of NLD, the pro-democracy party headed by Aung San Suu Kyi. The largest peace conference in the country’s history was held in early September, and Myanmar again made the international headlines a week later when Kofi Annan visited the country to head a commission for addressing communal violence. These national events are crucial to the democratization process in Myanmar and for ending the almost seven decades of civil war. However, often overlooked in this larger picture of transition is the state of local democracy, including village level governance and everyday state-citizen engagements. Political changes at this level are equally crucial for the wider democratization process.This roundtable summary discusses the 2016 local elections of village tract and urban ward administrators and reflects on the future of local democracy and decentralization in Myanmar. Local administrators are the primary point of contact between the state and citizens. How they are elected and how they govern in the everyday are essential to understanding political developments at the most local level.

Variability in the North Atlantic ocean heat transport at 26.5°N on short (5 day) timescales is identified and contrasted with different behaviour at monthly intervals using a combination of RAPID/MOCHA/WBTS measurements and the NEMO‐LIM2 1/12° ocean circulation/sea ice model. Wind forcing plays the leading role in establishing the heat transport variability through the Ekman transport response of the ocean and the associated driving atmospheric conditions vary significantly with timescale. We find that at 5 day timescales the largest changes in the heat transport across 26.5°N coincide with north‐westerly airflows originating over the American land mass that drive strong southward anomalies in the Ekman flow. During these events the northward heat transport reduces by 0.5–1.4 PW. In contrast, the Ekman transport response at longer monthly timescales is smaller in magnitude (up to 0.5 PW) and consistent with expected variations in the leading mode of North Atlantic atmospheric variability, the North Atlantic Oscillation. The north‐westerly airflow mechanism can have a prolonged influence beyond the central 5 day timescale and on occasion can reduce the accumulated winter ocean heat transport into the North Atlantic by ∼40%.

This study examines the seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) and its eastern boundary contributions. The cycle has a magnitude of 6 Sv, as measured by the RAPID/MOCHA/WBTS project array at 268N, which is driven largely by the eastern boundary. The eastern boundary variations are explored in the context of the regional circulation around the Canary Islands. There is a 3 month lag between maximum wind forcing and the largest eastern boundary transports, which is explained in terms of a model for Rossby wave generated at the eastern boundary. Two dynamic processes take place through the Lanzarote Passage (LP) in fall: the recirculation of the Canary Current and the north- ward flow of the Intermediate Poleward Undercurrent. In contrast, during the remaining seasons the trans- port through the LP is southward due to the Canary Upwelling Current. These processes are linked to the seasonal cycle of the AMOC., SI

RAPID - US AMOC International Science Meeting, Towards a holistic picture of the Atlantic Meridional Overturning Circulation : Via observation modelling and synthesis, 21-24 July 2015, Bristol, U.K., Mediterranean Outflow Water spreads into the North Atlantic Ocean below the thermocline, forming a tongue that slowly moves westward until it reaches the North American coast. Meanwhile, Labrador Sea Water formed at high latitudes in the North Atlantic flows southward along the American coast in the Deep Western Boundary Current, and flows on similar density levels as the Mediterranean Outflow Water. The two water masses mix at some point, to jointly cross the Equator in the Deep Western Boundary Current. The question is how and where this mixing happens. In particularly, it is unclear how variability in the strength of formation the two water mass relates and impacts on the southward export of mid-depth water. This is important because, while the two water masses have the same density, they have vastly different temperature and salinity properties. Better knowledge of the mixing processes will allow for an improved understanding of AMOC dynamics. Here, we show results from eddy-resolving models where we track the water flowing from both the southern tip of the Labrador Sea and the Strait of Gibraltar, using virtual Lagrangian particles. We analyse the trajectories of these particles to see where and how the two water masses mix, and reconcile this with information on the modeled and observed salinity field in the North Atlantic. We show what the role of meso-scale eddies is, and how the interaction of the two water masses ultimately sets the thermohaline structure of the mid-depth North Atlantic Ocean

MCCIP Science Review 2013, 49-59

For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Ni a-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in to the effects of La Ni a, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near-or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7 N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global 2 emissions from fossil fuel combustion and cement production reached a record 9.5 +/- 0.5 Pg C in 2011 and a new record of 9.7 +/- 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, 2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.

The Atlantic meridional overturning circulation (MOC) plays a critical role in the climate system and is responsible for much of the heat transported by the ocean. A mooring array, nomianally at 26$^\circ$N between the Bahamas and the Canary Islands, deployed in Apr 2004 provides continuous measurements of the strength and variability of this circulation. With seven full years of measurements, we now examine the interannual variability of the MOC. While earlier results highlighted substantial seasonal and shorter timescale variability, there had not been significant interannual variability. The mean MOC from 1 Apr 2004 to the 31 March 2009 was 18.5 Sv with the annual means having a standard deviation of only 1.0 Sv. From 1 April 2009 to 31 March 2010, the annually averaged MOC strength was just 12.8 Sv, representing a 30\% decline. This downturn persisted from early 2009 to mid-2010. We show that the cause of the decline was not only an anomalous wind-driven event from Dec 2009--Mar 2010 but also a strengthening of the geostrophic flow. In particular, the southward flow in the top 1100~m intensified, while the deep southward return transport---particularly in the deepest layer from 3000--5000~m---weakened. This rebalancing of the transport from the deep overturning to the upper gyre has implications for the heat transported by the Atlantic.

This thesis investigates the variability of the intermediate and thermocline water mass properties in the South Atlantic, with a particular focus on salinity. These water masses form the upper branch of the Meridional Overturning Circulation in the Atlantic and have an important position in global ocean climate. Variability on various timescales is investigated: decadal changes are investigated using repeat hydrographic surveys, interannual variability is investigated using Argo float data and the two timescales are united by investigating a 40 year modern ocean model run. Salinity of thermocline water masses is shown to vary slowly on decadal timescales. Basinwide changes in salinity are evident at 24?S over periods of 25 years. That these changes are representative of decadalchanges and not merely aliasing shorter term variability is supported by analysis of the model. Increases in salinity at 24?S from 1958 to 1983 and at 30?S from 1993 to 2003 are linked with influence from the Indian ocean while a freshening at 24?S from 1983 to 2009 may be linked with an intensified hydrological cycle. Antarctic Intermediate Water (AAIW) is seen to increase in salinity at 24?S from 1958 to 1983 and in the eastern basin at 30?S from 1993 to 2003. This is different from the Indian and Pacific Oceans where AAIW has been observed to be freshening – a change linked with the intensification of the hydrological cycle. Using the highly correlated relationship between salinity and oxygen in AAIW, these changes are linked to the influence of the Indian Ocean. Further investigation of the changes in AAIW in the South Atlantic using Argo data and model data show that the variability of this water mass is dominated by westward propagating salinity anomalies. These anomalies originate in the Agulhas influenced Cape Basin of the South Atlantic and propagate westwards with speeds similar to those predicted for second mode baroclinic Rossby waves. The techniques developed for analysis of AAIW salinity using oxygen data are expanded to the other oceans of the southern hemisphere. The conclusions drawn from this analysis put the AAIW in the South Atlantic in a global context.

The semiconductor industry relies on knowledge sharing and collaboration between its employees and amongst subsidiary companies to remain competitive in an ever changing, market driven environment. Practise has changed from workers supplying labour to workers supplying knowledge. Technology improvements and investment in automation have provided companies the platform to generate, codify, harness and exploit knowledge as a means of improving organisational performance. This research explores knowledge dynamics in the organisation and specifically looks at knowledge sharing within a subsidiary and among subsidiaries in a multinational corporation. The corporation in question operates its manufacturing facilities as competing business units. The purpose of the research was to establish if this method of organising business units provides the overall corporation with a competitive advantage, or if competing business units inhibits performance preventing or restricting the potential for a competitive advantage for the corporation. To determine how knowledge is shared within the organisation a series of semi-structured interviews were conducted. Senior managers and professional staff across a number of disciplines were interviewed. Knowledge sharing within functional area departments, collaboration between functional area departments, knowledge systems and compliance to knowledge systems were used as determinants to establish the extent of the knowledge dynamic in the subsidiary. The relationship between knowledge sharing and how it impacted the “bottom line” performance of the subsidiary was also considered in an attempt to quantify the impact knowledge sharing has on performance. To determine how knowledge is shared between subsidiaries, two case studies were conducted. The first case study involved a benchmarking visit to allow two of the corporation’s subsidiaries to compare best practice cost systems with multi-disciplines involved. The second case study involved a cross functional team of technical staff to define a manufacturing facility technical yield roadmap. Significant cost, productivity and yield improvement at the site was attributed to the success of collaborative units established at site. Establishing collaborative units was a precursor to setting up a network within the site to promote knowledge sharing in the organisation. The site was cognisant of the impact of effective knowledge sharing and receptive to sharing knowledge on an informal or formal basis. The site put great stock in codified knowledge and invested heavily in automating knowledge based systems. Many barriers to knowledge sharing were identified including compliance to codified procedures, departmental conflicts, viewing knowledge sharing as a burden, variation across automated systems, conflicts caused by the internet as a knowledge source and logistics due to geographical dispersion. Knowledge-led teams overcame many of these barriers. Success bred success to the extent knowledge sharing has become a business process in the organisation. Knowledge sharing is a two way process. It can be a vehicle for trust, respect and improvement. This research has shown knowledge sharing even within competing business units can produce a competitive advantage. An organisation is an accumulation of knowledge. A knowledge-led collaborative approach provides many benefits: it will advance the company, engage staff at all levels and favourably impact the “bottom line”. Knowledge management differentiated the local site from other corporate subsidiaries with the local site demonstrating “best in class” results on its key performance indicators. Encouragingly, there is ample opportunity to improve performance further once knowledge management is fully embedded as a business process across the organisation.

Presentation held at theClimate Science2Policy workshop on 17-18 November 2020. The event was organised by the Executive Agency for Small and Medium-sized enterprises (EASME), European Commission, in collaboration with a cluster of H2020 Earth System Science projects, like Blue-Action.

Poster presented at the Understanding Change and Variability in the North Atlantic Climate System, ACSIS - OSNAP - RAPID, Joint Science Meeting, 19-21 September 2017, Oxford, UK.

Overview of Work Package 2 of Blue-Action "Lower latitude drivers of Arctic change"

A novel ocean mixed layer heat budget analysis methodology is developed and used to investigate the physicalprocesses which determine Subpolar North Atlantic (SPNA) SST and OHC variability on decadal-multidecadaltimescales using the state-of-the-art coupled climate model HadGEM3-GC2. Contributions to OHC and SSTvariability from three sources are evaluated i) the net ocean-atmosphere heat flux, ii) divergence of the oceanichorizontal temperature transport and iii) entrainment between the ocean surface mixed layer and the layer beneath.Anomalies in OHC and SST tendency propagate anticlockwise around the SPNA on multidecadal timescaleswith a clear relationship to the Phase of the AMOC. AMOC anomalies lead SST tendencies which in turn leadOHC tendencies. This result is common to both eastern and western SPNA, although the primary driver of OHCvariability differs with surface fluxes dominant in the west and advection-diffusion in the east. The reciprocal ofthe mixed layer depth is found to be an important variable which causes SST to respond faster to AMOC changesthan OHC. The implications of these new results for interpretation of lower resolution coupled models, includingmany of those used in the CMIP6 assessment are discussed.

Presentation at the AGU Ocean Sciences Meeting, Portland Oregon, 11-16th February 2018. PL23A: Atlantic Meridional Overturning Circulation: Modeling and Observations

Presentation at: Blue-Action 2018 Annual Meeting, 19th January 2018, Bologna, Italy

The North Atlantic is notable for large decadal variability in sea surface temperature (SST) manifested as Atlantic Multi-decadal Variability (AMV). Whether the AMV is driven by external atmospheric or internal oceanic influences is an oft-disputed point. Long time series of atmospheric and ocean variables, in particular long timeseries of Gulf Stream position, reveal differing drivers of SST variability on quasi- and multi-decadal timescales. On quasi-decadal timescales an oscillatory signal identified in the North Atlantic Oscillation controls SST evolution directly via air-sea heat uxes. However, on multi-decadal timescales this relationship with SST changes, while remaining consistent in phase. and resonant in amplitude with Gulf Stream position. A recent reversal of the long term positive trend in Gulf Stream position coincides with a weakening and broadening in the Gulf Stream Extension indicating the onset of an AMV decline.

Presentation at: ACSIS Ocean-Ice Theme Science Day, 27th April, National Oceanography Centre, UK.

List of the presentations included in this collection: Welcome (Gerard McCarthy, NUIM) Introduction to the observing arrays NOAC (Martin Moritz, BSH) Greenland-Scotland Ridge (Berit Rabe, MSS) Observing the Slope Current The European Slope Current (Martin White, NUIG) Observing and Understanding the Slope Current (Marie Porter and Neil Fraser, SAMS) Decadal predictions (Andre Duesterhus, NUIM) Modelling in the Eastern Subpolar Gyre Modelling the Slope Current (Bob Marsh, Univ. Southampton) Nested models on the shelf (Tomasz Dubrowski, Irish Marine Institute), Blue-Action and Atlas have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 727852 (Blue-Action) and No 678760 (ATLAS). A4 (Aigéin, Aeráid, agus athrú Atlantaigh) is funded by the Marine Institute and the European Regional Development fund (grant: PBA/CC/18/01)

These four presentations have been the core of the side event to the All-Atlantic 2021 conference "Atlantic Pole to Pole: Climate Science 2 Policy" held on 2nd June 2021, as an online event. The side event was organised by four Horizon 2020 projects: Blue-Action, MISSION ATLANTIC, SO-CHIC and TRIATLAS. The recording of the entire event is also available here below. The policy briefing linked to this side event is available here: https://zenodo.org/record/4889819 We would like to thank once again all the participants!, The Blue-Action, MISSION ATLANTIC, SO-CHIC, and TRIATLAS projects have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 727852, 862428, 821001, 817578 respectively.

Presentation at: Understanding Change and Variability in the North Atlantic Climate System, ACSIS - OSNAP - RAPID Joint Science Meeting,19-21 September 2017, Oxford, UK.

A novel ocean mixed layer heat budget analysis methodology is developed and used to investigate the physicalprocesses which determine Subpolar North Atlantic (SPNA) SST and OHC variability on decadal-multidecadaltimescales using the state-of-the-art coupled climate model HadGEM3-GC2. Contributions to OHC and SSTvariability from three sources are evaluated i) the net ocean-atmosphere heat flux, ii) divergence of the oceanichorizontal temperature transport and iii) entrainment between the ocean surface mixed layer and the layer beneath.Anomalies in OHC and SST tendency propagate anticlockwise around the SPNA on multidecadal timescaleswith a clear relationship to the Phase of the AMOC. AMOC anomalies lead SST tendencies which in turn leadOHC tendencies. This result is common to both eastern and western SPNA, although the primary driver of OHCvariability differs with surface fluxes dominant in the west and advection-diffusion in the east. The reciprocal ofthe mixed layer depth is found to be an important variable which causes SST to respond faster to AMOC changesthan OHC. The implications of these new results for interpretation of lower resolution coupled models, includingmany of those used in the CMIP6 assessment are discussed.

Presentation at: Understanding Change and Variability in the North Atlantic Climate System, ACSIS - OSNAP - RAPID Joint Science Meeting,19-21 September 2017, Oxford, UK.

Poster presented at the Understanding Change and Variability in the North Atlantic Climate System, ACSIS - OSNAP - RAPID, Joint Science Meeting, 19-21 September 2017, Oxford, UK.

Presentation describing Comparison of sea-level based ocean circulation indices

Presentation at: ACSIS Ocean-Ice Theme Science Day, 27th April, National Oceanography Centre, UK. &nbsp

Presentation at: Blue-Action 2018 Annual Meeting, 19th January 2018, Bologna, Italy

About this document Deliverable: D6.1 First Joint workshop to (re)formulate open research questions of joint interest: “Tipping Elements in the Climate System, with a Focus on the North Atlantic” Work package in charge: WP6 Clustering Actual delivery date for this deliverable: Project-month 13 Dissemination level: The general public (PU) Lead author: Natural Environment Research Council, National Oceanography Centre (NOC): Gerard McCarthy Other contributing author: Danish Meteorological Institute (DMI): Chiara Bearzotti Summary for publication The first joint workshop on areas of common interest was held on 18-19 September 2017 at Wolfson College, Oxford (UK). The focus of the workshop was tipping elements in the climate system, with a focus on the North Atlantic. Blue-Action is focused on Arctic and high latitude changes. Therefore, the high number of tipping elements in this region and their potentially large impact on Northern Hemisphere climate is of particular interest and concern to Blue-Action scientists. The workshop was organised by the Blue-Action project to link Blue-Action scientists with experts outside the project. Key areas of research and actions for future collaboration were identified., We support the Blue Growth! Visit us on: www.blue-action.eu Follow us on Twitter: @BG10Blueaction