The turbulent ocean - the role of eddies for ocean biogeochemistry
Event details
| Date | 02.12.2014 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Nicolas Gruber, Environmental Physics, ETH Zürich |
| Location | |
| Category | Conferences - Seminars |
Abstract:
The ocean is a highly turbulent medium - with mesoscale eddies dominating the variability spectrum. These mesoscale eddies are the oceanic analogue of high and low pressure systems in the atmosphere, except that their horizontal scales are only tens to a hundred kilometres. Despite their ubiquity, the role of these eddies for ocean circulation and particularly for ocean biogeochemistry is neither well observed nor well understood, and a source of many surprising findings. In my talk, I will discuss two oceanic realms, where eddies might play a particularly important role, i.e., Eastern Boundary Upwelling Systems, such as the California Current System, and the Southern Ocean. I will demonstrate on the basis of observations and modeling studies that mesoscale eddies are not just adding "noise" to these systems, but also modify their mean state. In the California Current System, for example, eddies are the dominant pathway for the transport of material properties from the near coastal system into the open ocean, thereby depleting the near-coastal reservoir of the nutrients, which leads to a substantially lower than expected biological production in this system. In the Southern Ocean, a similar process is at work, playing a critical role in how this system is responding to changes in wind-induced upwelling. In addition, I will show how such mesoscale eddies modify the atmospheric boundary layer, causing changes in winds and rainfall. Since oceanic mesoscale eddies are typically not resolved by today's climate models, our insights are a crucial first step to develop parameterizations to represent their integrative effect, ultimately leading to better predictions of how Earth's climate system will respond to future perturbations and those of the past.
Short biography:
Nicolas Gruber (1968) has a Diploma in environmental sciences from the Swiss Federal Institute of Technology (ETH) Zurich and a Ph.D. from the University of Bern (1997). Subsequently he was as Visiting Research Scientist with the AOS program at the University of Princeton for three years. From 2000-2005 he worked as an Assistant Professor at the Department of Atmospheric and Oceanic Sciences at the University of California, Los Angeles, where he received tenure in 2005. In 2006 he returned to Switzerland to become Professor for Environmental Physics at ETH Zurich. His main research interest are the global biogeochemical cycles of carbon and other biologically essential elements and their interaction with the climate system. He combines the analysis of observations with modeling studies to better quantify, for example, the fate of the anthropogenic CO2 emissions in the Earth system, particularly the uptake by the ocean and land biosphere.
The ocean is a highly turbulent medium - with mesoscale eddies dominating the variability spectrum. These mesoscale eddies are the oceanic analogue of high and low pressure systems in the atmosphere, except that their horizontal scales are only tens to a hundred kilometres. Despite their ubiquity, the role of these eddies for ocean circulation and particularly for ocean biogeochemistry is neither well observed nor well understood, and a source of many surprising findings. In my talk, I will discuss two oceanic realms, where eddies might play a particularly important role, i.e., Eastern Boundary Upwelling Systems, such as the California Current System, and the Southern Ocean. I will demonstrate on the basis of observations and modeling studies that mesoscale eddies are not just adding "noise" to these systems, but also modify their mean state. In the California Current System, for example, eddies are the dominant pathway for the transport of material properties from the near coastal system into the open ocean, thereby depleting the near-coastal reservoir of the nutrients, which leads to a substantially lower than expected biological production in this system. In the Southern Ocean, a similar process is at work, playing a critical role in how this system is responding to changes in wind-induced upwelling. In addition, I will show how such mesoscale eddies modify the atmospheric boundary layer, causing changes in winds and rainfall. Since oceanic mesoscale eddies are typically not resolved by today's climate models, our insights are a crucial first step to develop parameterizations to represent their integrative effect, ultimately leading to better predictions of how Earth's climate system will respond to future perturbations and those of the past.
Short biography:
Nicolas Gruber (1968) has a Diploma in environmental sciences from the Swiss Federal Institute of Technology (ETH) Zurich and a Ph.D. from the University of Bern (1997). Subsequently he was as Visiting Research Scientist with the AOS program at the University of Princeton for three years. From 2000-2005 he worked as an Assistant Professor at the Department of Atmospheric and Oceanic Sciences at the University of California, Los Angeles, where he received tenure in 2005. In 2006 he returned to Switzerland to become Professor for Environmental Physics at ETH Zurich. His main research interest are the global biogeochemical cycles of carbon and other biologically essential elements and their interaction with the climate system. He combines the analysis of observations with modeling studies to better quantify, for example, the fate of the anthropogenic CO2 emissions in the Earth system, particularly the uptake by the ocean and land biosphere.
Practical information
- General public
- Free
- This event is internal
Organizer
- EESS - IIE
Contact
- Prof. Samuel Arey, coordinator