Nele Tim successfully defended her Ph.D thesis in 2015. Congratulations!

Title of Ph.D. thesis

Influence of large-scale climate variability on upwelling regimes off the Namibian coast: implications for past and future climates

Supervising tutors:

Dr. Birgit Hünicke, Coastal Impacts
Dr. Eduardo Zorita, Paleoclimatology

Helmholtz-Zentrum Geesthacht, Institute of Coastal Research

Outline sub-project 1, GENUS-II:

The Namibian Upwelling System is one of the four major Eastern Boundary Upwelling Ecosystems. The climatological upwelling regime is driven by the wind stress field off Southwest Africa, but which factors modulate the upwelling strength at long-term scales is less well known. Large-scale oceanic circulation systems, large-scale atmospheric forcing, changes in the stratification and regional land-sea temperature contrast, which modulates the local wind could affect the upwelling system. At longer time scales, coastal upwelling can  influence the thermal land-sea contrast, thus modulating the regional wind regime. Therefore, not only past climates but also future scenarios are of interest.

My research is focused on the causes for long-term variations at decadal and longer time scales of upwelling off the Namibian coast. This will be investigated by statistically analysing a series of observation data sets and climate simulations with atmosphere-only, ocean-only and coupled climate models that cover the present state, the 21st century and the past millennium.

Main topics of the investigation of my doctoral thesis:

• large-scale atmospheric indicators which influence the upwelling

• highly-resolved atmospheric processes with effect on the upwelling

• future changes in those forcings