NP Campfires – Emergent Phenomena in Geosciences (NP8)
Join us for the third session of our NP Division Campfires, where we explore the emergent phenomena in the geosciences. Led by Prof. Henk Dijkstra, this one-hour session will unravel the complexities in urban geosciences and tipping points. Mark your calendars for Tuesday, November 21st, at 10 CET on Zoom.
Prof. Daniel Schertzer
Complexity in Urban Geosciences: an emerging research field in Nonlinear Geosciences
Following a Great Debate at EGU 2017 and several Town Halls, Inter- Transdisciplinary sessions have been regularly organised on Urban geosciences, with a particular NP division support. Howe-ver much more remains to be done to tackle the interactions between urban systems and their envi-ronment as a key issue for the appropriate climate change adaptation and mitigation, as well as for achieving the UN Sustainable Development Goals (SDGs), in particular SDG11 on resilient cities. Indeed, the involvement of the NP community is already indispensable for linking together differ-ent scales: rather large for geophysics, much smaller for urban management and planning.
More generally, the interdisciplinary culture of NP is needed to deal with complexity in urban geo-sciences on the basis of data and/or theories, either at the methodological level or at the level of original applications. While complexity is too often confused with the complicated or the difficult, it has fairly precise definitions such as “a system comprised of a great number of heterogeneous enti-ties, among which local interactions create multiple levels of collective structure and organisa-tion…”. New concepts, methodologies and disruptive models are therefore needed to overcome cur-rent scientific bottlenecks, to better deal with non-linearities, multi-component systems, stochastic synchronisation, tipping points and elements, and extremes over a wide range of scales in geophysi-cal and urban systems, as well as their interactions in human-environment systems.
Part of the future growth of NP may depend on our ability to take up this challenge. Let’s discuss it.
Dr. Robbin Bastiaansen
Tipping in spatially extended systems
In the current Anthropocene, there is a need to better understand the catastrophic effects that climate and land-use change may have on ecosystems, earth system components and the whole Earth system. The concept of tipping points and critical transitions contributes to this understanding. Tipping occurs in a system when it is forced outside the basin of attraction of the original equilibrium, resulting in a critical transition to an alternative, often less-desirable, stable state. The general belief and intuition, based on simple conceptual models of tipping elements (i.e. ordinary differential equations), is that tipping leads to reorganization of the full (sub)system. In this talk, I will review and explore tipping in conceptual, but spatially extended, and potentially spatially heterogeneous, models (i.e. partial differential equations). In these spatially explicit models, additional stable states can emerge that are not uniform in space, such as Turing patterns and coexistence states (part of the domain in one state, the rest in another state with a spatial interface or front between these regions), which can lead to a different tipping behaviour. In particular, in these systems a tipping point might lead only to a slight restructuring of the system or to a tipping event in which only part of the spatial domain undergoes reorganization, limiting the impact of these events on the system’s functioning.
If you have any questions about the ‘NP Campfires – Emergent Phenomena in Geosciences (NP8)’ webinar, please contact us via webinars@egu.eu.