Research Fellows Directory
Mohamed Mahmoud Ezat
Dr Mohamed Mahmoud Ezat
University of Cambridge
The Arctic Ocean is shifting to a new state in unexpected ways with serious implications for earth's climate, resource managements, and the marine ecosystems. One important example is the ongoing shrinkage of the Arctic sea ice thickness and extent, which is by far more rapid than predicted by climate models. A second, relatively overlooked aspect is the ongoing changes in the Arctic marine carbon cycle, including rapid acidification of seawater (i.e., decrease of seawater pH) and changes in the CO2 exchange with the atmosphere.
A broader paleoclimatic perspective allows a wide range of boundary conditions to be investigated, which has the potential to improve our understanding of the interplay and feedback processes between climate, Arctic hydrography and the carbon cycle. In this context, there has been major progress in the use of the elemental and isotopic composition of calcium carbonate parts of foraminifera, which are unicellular organisms, to reconstruct past oceanographic conditions. However, these methods have been seldom applied to the Arctic Ocean mainly because of the limited availability of foraminifera and diagenetic alterations.
To overcome these complications, I utilize novel micro-analytical techniques that are capable of measuring highly resolved elemental- and isotopic compositions of single foraminifera. Doing so, I aim to quantify the Arctic's carbon cycle-climate feedbacks beyond the observational records by combining proxies for Arctic Ocean hydrography (e.g., temperature, salinity and sea ice cover), primary productivity and seawater carbonate chemistry (e.g., pH and concentration of CO2) for most of the past two million years. This work will help unraveling the role of the Arctic Ocean as a regulator of the past changes in climate and atmospheric CO2; knowledge that will help improving our ability to project future changes in the Arctic Ocean climate system and their consequences.
Interests and expertise (Subject groups)