Karin Kvale - Marine transitions in warming icehouse and cooling greenhouse worlds

Event type: 
Seminar
Date: 
13 February 2019
Time: 
2.00 - 3.00pm
Location: 

Climate Change Research Centre, Seminar Room, Mathews Building 4th floor, UNSW, Sydney

Presenter: 
Dr. Karin Kvale
GEOMAR - Helmholtz Centre for Ocean Research, Kiel, Germany
Host: 
Climate Change Research Centre

Greenhouse climates have dominated Earth’s history, which suggests they may be the most stable of the climate states. Karin explores the unique ocean characteristics of idealised icehouse and greenhouse climates using the University of Victoria Earth System Climate Model (UVic ESCM), and qualitatively define them in terms of their biogeochemistry and circulation. These definitions reveal a mismatch between what CMIP models project as ocean trends to the year 2300, and what the UVic ESCM equilibrates to in a greenhouse state. Karin next explores the icehouse and greenhouse ocean response to symmetric rapid atmospheric CO2 forcing- a 1% per year increase (decrease) for 150 years in an icehouse (greenhouse) climate, then held constant for 350 years. These idealised simulations reveal a strong asymmetry in physical and biogeochemical response and suggest mechanisms that could partially explain the greater stability of greenhouse climates. Lastly Karin discusses the role of phytoplankton calcifiers in the low latitudes in reducing the magnitude of shifts in biogeochemistry between climate states.

 

Brief Biography: Karin has been a postdoc in the Biogeochemical Modelling department of GEOMAR Helmholtz Centre for Ocean Research- Kiel since 2014. Her recent work has focused on biogeochemical model parameter optimisation using an offline framework, though greenhouse climates and the role of ecology in global biogeochemical cycles are side interests. She obtained her PhD at the CCRC in 2014, with her implementation of an explicit calcifier phytoplankton type in the UVic ESCM.