Large-Scale Circulation and Climate Variability

Melanie Schnohr, Lev Naumov, Florian Börgel

Large-Scale Circulation and Climate Variability

The Junior Research Group investigates the internal and external drivers of climate variability, with a particular focus on large-scale circulation, decadal to multi-decadal variability, and the regional expression of these signals in the Baltic Sea and Northern Europe. Our work combines process understanding, climate modelling, and data-driven approaches to improve knowledge of long-term predictability, extreme events, and their impacts on marine and coastal systems.

We focus our research on the Baltic Sea - one of Europe’s most socioeconomically sensitive regions - but will extend our research to other coastal seas.

Figure 1: ICON-Coast grid (underlying figure) and examples of the coastal systems worldwide experiencing hypoxia. The bathymetry was taken from GEBCO (https://www.gebco.net) and interpolated to the native ICON-Coast grid. The Figure is adapted from Fennel and Testa (2019).

A growing focus of the group is the translation of large-scale climate information into regional and coastal applications. In this context, we contribute to the IOW-led SeaGuard project, which integrates regional climate modelling, optical remote sensing, and machine-learning approaches to identify climate-resilient restoration areas and assess the future potential of seagrass meadows under changing environmental conditions.

Key Research Areas

Understanding Climate Variability
We investigate the mechanisms behind decadal and multi-decadal climate variability and examine how large-scale climate signals shape marine and coastal conditions in the Baltic Sea region and Northern Europe. Particular attention is given to teleconnections between the North Atlantic and the Baltic Sea, and to the regional consequences of large-scale climate drivers.

Extreme Events and Predictability
We study climate-related extremes such as marine heatwaves and other high-impact events, and assess the potential for improved prediction on seasonal to decadal timescales. This includes efforts to better understand how extreme events emerge from, or depart from, the background of natural climate variability.

Oxygen Variability and Marine Biogeochemistry
We examine how circulation changes, inflow dynamics, and climate variability affect oxygen conditions and biogeochemical processes in the Baltic Sea. This work contributes to a better understanding of hypoxia, ventilation, and ecosystem-relevant changes in marginal seas.

Regional Climate Projections and Coastal Applications
We use regional and high-resolution model systems to assess future environmental conditions in vulnerable coastal systems, including the Greifswalder Bodden. A central goal is to improve the scientific basis for understanding seagrass persistence, restoration potential, and coastal climate adaptation under changing climate and nutrient conditions