Ernst Maier-Reimer (1944-2013)
Ernst Maier-Reimer was a pioneer of ocean carbon cycle modelling.
Ernst received an education in high energy physics before starting a career in oceanography.
At the Institute for Marine Research at the University of Hamburg, he developed regional physical-dynamical ocean models and started to implement Eulerian as well as Lagrangian tracers in his circulation models.
As an early staff member of the Max Planck Institute for Meteorology in Hamburg, he succeeded in constructing a new global ocean model for climate research. His Large Scale Geostrophic (LSG) ocean model was sensational in the 1980s: the LSG model could predict water masses even in the deepest layers of the world’s oceans and be integrated over thousands of years due to the skilled combination of suitable numerical algorithms. No other global circulation model was as computationally economic– an ideal tool for carbon cycle studies.
On the basis of the LSG model, Ernst developed the HAMOCC model, the HAMburg Ocean Carbon Cycle circulation model, and provided the first three-dimensional simulation of the ocean carbon cycle in 1987. This landmark study included a suite of anthropogenic emission scenarios that were integrated over one millennium. He could unequivocally show that keeping CO2 emissions at a reduced level would have a tremendously positive effect on the airborne fraction of CO2. The HAMOCC model became the blue-print for a new generation of biogeochemical ocean models. Ernst added a long suite of different tracers and processes to his models. A strength of his approach was the strict mass conservation and the internal consistency of the coupled tracer systems. His implementations included prey-predator systems, ecosystem models, sediment models and eddy-resolving physical ocean models.
His physical and biogeochemical ocean general circulation models were among the most efficient computer codes ever written in Earth system science. They enabled the first long global runs to achieve quasi drift-free equilibrium. He pursued a multi-tracer approach that constrained carbon budgets through a wide range of additional tracers.
Ernst was a kind and generous teacher and a modest human being. His influence on ocean carbon cycle modelling was tremendous.
Ernst was a follower and participant of the ICDCs. We owe much to him, and miss him greatly.
(March, 2016, C. Heinze)