ALBERT

Description: In the equatorial Atlantic Ocean, meridional velocity variability exhibits a pronounced peak on intraseasonal timescales whereas zonal velocity dominantly varies on seasonal to interannual timescales. We focus on the intraseasonal meridional velocity variability away from the near-surface layer, its source regions and its pathways into the deep ocean. This deep intraseasonal velocity variability plays a key role in equatorial dynamics as it is an important energy source for the deep equatorial circulation. The results are based on the output of a high-resolution ocean model revealing intraseasonal energy levels along the equator at all depths that are in good agreement with shipboard and moored velocity data. Spectral analyses reveal a pronounced signal of intraseasonal Yanai waves with westward phase velocities and zonal wavelengths longer than 450 km. Different sources and characteristics of these Yanai waves are identified: near the surface between 40°W and 10°W low-baroclinic-mode Yanai waves with periods of around 30 days are exited. These waves have a strong seasonal cycle with a maximum in August. High-frequency Yanai waves (10–20-day period) are excited at the surface east of 10°W. In the region between the North Brazil Current and the Equatorial Undercurrent high-baroclinic-mode Yanai waves with periods between 30 and 40 days are generated. Yanai waves with longer periods (40-80 days) are shed from the Deep Western Boundary Current. The Yanai wave energy is carried along beams east- and downward thus explaining differences in strength, structure and periodicity of the meridional intraseasonal variability in the equatorial Atlantic Ocean.

Description: In the last years, the concept of tipping points received increasing recognition in social science and rose on the political agenda. Identifying tipping points would allow researchers to identify the point in time in which a transition happens, and to understand the processes of overcoming lock-in mechanisms and trigger deliberate tipping an existing system into a qualitatively new state. Because tipping points bring about rapid systemic change, it is desirable to further understand how tipping points may be triggered to accelerate the transformation of social and economic systems. There is little doubt that tipping points exist in both social and socio-technical systems because we can observe that systems and societies are fundamentally different today than they were in the past. However, despite a growing body of literature, there remain many open questions how to conceptualise and ultimately operationalize social tipping points. This also stems from a lack of empirical studies and insights observing tipping points in social contexts. In the Tipping.Plus project we addressed this gap with a literature review and empirical case studies investigating tipping dynamics from a public policy and governance perspective. In the literature review we explored definitions, characteristics, and the application of the concept and notion of tipping points in political and governance theories and contexts. In the second step, we conducted an empirical study investigating the socio-economic transition processes of the two German neigbouring cities Essen and Duisburg, which have both phased out their coal industries, as part of the wider structural change in the Ruhr Region. We focused on (political) interventions and their effects on the cities’ development trajectories in the last 30+ years to identify differences in outcome as a function of policy interventions and/or contextual differences. Apart from identifying the key development drivers, we investigate whether either city crossed a tipping point in their transition process (yet), away from coal towards a low carbon but still prosperous future (Mey and Lilliestam 2022). In the following we synthesise the findings of this work and our observations and experiences in order to contribute to the overall Tipping.Plus Integration Framework and Social Theory on social tipping points in energy transitions.

Description: In this report, we identify the needs of the energy model users and the users of energy model results in policy, industry, civil society, and science, both in the present and future. Based on a comprehensive literature review, qualitative interviews in five European jurisdictions, a survey, and a workshop, we identify what different user groups need from energy models: What types of questions, input, and results are useful to them? We also identify user needs regarding the modeling platform of SENTINEL: How do we need to define such a platform to make it worthwhile for potential users?

Description: This report contributes to the modelling work in SENTINEL and beyond in two main ways. First, we provide three social storylines that are closely linked to different governance logics and build on observed social and political drivers and barriers in the European energy transition. This is different than most other storylines used for modelling, because ours are based on governance patterns and normative assumptions of a “good future”, and not on the more common geopolitical or techno-economic storyline assumptions. Second, we provide quantitative, empirical data for several important social/political parameters that can be used together with the storylines or as separate building blocks to answer specific research questions with energy models.

Description: The decarbonisation of the European energy system is a large-scale transformation, which demands not only for a techno-economic feasibility analysis, but also for an assessment of the social and political feasibility and environmental impacts. However, most energy models are not able to fully represent the social and political developments and dynamics of the energy transition, such as preferences, acceptance and behavioural changes of citizens and decision-makers. To address this shortcoming, we developed QTDIAN (Quantification of socio-Technological DIffusion and sociAl constraiNts) − a toolbox of qualitative and quantitative descriptions of socio-technical and political aspects of the energy transition. In this deliverable, we present and discuss the linking of QTDIAN with the energy demand models DESSTINEE, HEB and DREEM, and the energy system model Euro-Calliope. The purpose of linking the models is to integrate the outputs from QTDIAN into the energy models to allow for an empirically based and thus more realistic analysis of energy system trajectories, with a higher relevance for informing pending policy decisions. The central question we address is: How can the social storylines and quantifications from QTDIAN be transferred into energy demand and systems models? We show several ways how QTDIAN’s quantified variables allow for a direct application of the storylines into the modelling process of Euro-Calliope, DESSTINEE, HEB and DREEM. The qualitative storylines ensure that modellers do not create technically feasible energy systems that are outside the realms of social or political realities. In addition, the quantitative data can be used to improve the accuracy and especially the policy relevance of the modelling results by providing specific estimates for social and political variables and constraints. However, not all aspects of QTDIAN could be integrated because not all aspects of the storylines could be quantified, and the models to which QTDIAN links in this deliverable are not able to capitalise on all QTDIAN outputs. We identified further requirements for data, including different temporal and spatial scales. We conclude that the linking of QTDIAN with energy demand and energy systems models is a promising approach to better represent socio-political drivers and barriers for technology changes and climate change mitigation measures. We will run the models with the integrated linkage with QTDIAN to evaluate the outcomes and added value of the linking in the context of SENTINEL case studies (WP7).

Description: In this paper, we investigate the socio-economic transition processes of Essen and Duisburg as part of the wider structural change in the Ruhr Region. In the two case studies, we explore causes and effects of the cities’ development trajectories in the last 30+ years, seeking to identify differences in outcome as a function of the interventions and/or contextual differences. We analyse events, interventions and their impacts on the social and economic systems of the two cities across time. Apart from identifying the key development drivers, we investigate whether either city crossed a tipping point in their transition process (yet), away from coal towards a low-carbon but still prosperous future. Therefore, we specifically evaluate the cities’ development trajectories by seeking evidence for “no”, “incremental” or “radical” changes in a set of indicators. Here, we have taken a long temporal perspective, because trajectories of and trajectory changes in social systems are specifically visible in demographic dynamics, economic structures and political arrangements across time.

Description: This report contributes to the modelling work in SENTINEL and beyond in three main ways. First, we provide three social storylines that are closely linked to different governance logics and build on observed social and political drivers and barriers in the European energy transition. This is different than most other storylines used for modelling, because ours are based on governance patterns and normative assumptions of a “good future”, and not on the more commonly used geopolitical or techno-economic storyline assumptions. Second, we provide quantitative, empirical data for several important social/political parameters that can be used together with the storylines or as separate building blocks to answer specific research questions with energy models. Third, to test the usefulness of QTDIAN, we have soft-linked QTDIAN with the energy demand models DESSTINEE, HEB and DREEM, the energy system design model Euro-Calliope, and indirectly with the economic model WEGDYN. Based on feedback from the modelling exercises, we have revised QTDIAN and publish now this updated report 2.0 to improve its usefulness for a more realistic analysis of potential future energy systems.

Description: Marine heatwaves along the coast ofWestern Australia, referred to as Ningaloo Niño, have had dramatic impacts on the ecosystem in the recent decade. A number of local and remote forcing mechanisms have been put forward, however little is known about the depth structure of such temperature extremes. Utilizing an eddy-active global Ocean General Circulation Model, Ningaloo Niño and the corresponding cold Ningaloo Niña events are investigated between 1958-2016, with focus on their depth structure. The relative roles of buoyancy and wind forcing are inferred from sensitivity experiments. Composites reveal a strong symmetry between cold and warm events in their vertical structure and associated large-scale spatial patterns. Temperature anomalies are largest at the surface, where buoyancy forcing is dominant and extend down to 300m depth (or deeper), with wind forcing being the main driver. Large-scale subsurface anomalies arise from a vertical modulation of the thermocline, extending from the western Pacific into the tropical eastern Indian Ocean. The strongest Ningaloo Niños in 2000 and 2011 are unprecedented compound events, where long-lasting high temperatures are accompanied by extreme freshening, which emerges in association with La Niñas, more common and persistent during the negative phase of the Interdecadal Pacific Oscillation. It is shown that Ningaloo Niños during La Nina phases have a distinctively deeper reach and are associated with a strengthening of the Leeuwin Current, while events during El Niño are limited to the surface layer temperatures, likely driven by local atmosphere-ocean feedbacks, without a clear imprint on salinity and velocity.

Description: The Antarctic Slope Front (ASF) is a fundamental feature of the subpolar Southern Ocean that is still poorly observed. In this study we build a statistical climatology of the temperature and salinity fields of the upper 380 m of the Antarctic margin. We use a comprehensive compilation of observational datasets including the profiles gathered by instrumented marine mammals. The mapping method consists first of a decomposition in vertical modes of the combined temperature and salinity profiles. Then the resulting principal components are optimally interpolated on a regular grid and the monthly climatological profiles are reconstructed, providing a physically plausible representation of the ocean. The ASF is located with a contour method and a gradient method applied on the temperature field, two complementary approaches that provide a complete view of the ASF structure. The front extends from the Amundsen Sea to the eastern Weddell Sea and closely tracks the continental shelf break. It is associated with a sharp temperature gradient that is stronger in winter and weaker in summer. The emergence of the front in the Amundsen and Bellingshausen sectors appears to be seasonally variable (slightly more westward in winter than in summer). Investigation of the density gradients across the shelf break indicates a winter slowdown of the baroclinic component of the Antarctic Slope Current at the near surface, in contrast with the seasonal variability of the temperature gradient.