To illustratre the field of environmental research, here is a description of one of the projects currently using our system. The list of all current projects contains links to more project descriptions.
Oceanic currents play an important role for the global climate. By overturning enormous amounts of water they shape the distribution of heat on Earth and are responsible for the uptake and transport of anthropogenic carbon dioxide. An improved understanding of ocean dynamics is essential for climate research.
A key region for the oceanic overturning is the waters around South Africa: The Agulhas Current transports warm and saline water masses from the tropical Indian Ocean southward along the South African coast. Parts of it reach the Atlantic Ocean in form of ocean eddies and are able to influence the deep-water formation in the North Atlantic. This “Agulhas leakage” is a nonlinear process that varies from year to year and on decadal timescales. Most probably as a result of global warming, Agulhas leakage has been increased over the past decades. An important factor are the Southern hemispheric westerly winds that change due to climate change and the development of the Antarctic ozone hole.
Modelling the regional dynamics and its global impact requires high resolution to simulate the small-scale processes, but also considering large-scale feedbacks in the ocean and the atmosphere (dynamics and chemistry). This is achieved by the FOCI model system developed at GEOMAR. An important feature of the ocean component NEMO is the nesting which allows to embed regional grids with 1/10° to 1/60° resolution into coarser resolved global models.
The scientific topics range from impacts and processes of small-scale ocean dynamics to global climate variability.
Figure 1: Snapshot of surface speed (in m s−1) as simulated in the nested area of (INALT20) (from Schwarzkopf et al., 2019)
Figure 2: Snapshot of normalized relative vorticity (rotary motions in s-1) in the 1/60° nest (INALT60) around South Africa
Figure 3: Snapshot of sea surface temperature and wind in the global climate model FOCI with a 1/10° nest (INALT10X)