Finger-rafted sea ice, seen from the helicopter.

Photo: Nick Cobbing

William Trossel scanning sea ice in Fram Strait

(Photo: Nick Cobbing)

 

A further, related, interest of mine is with the predictability of abrupt climate transitions. Can we identify early warning signals that would indicate climate 'tipping points', and potentially even allow us to avoid such tipping points. A study on this topic, entitled 'Early Warning Signals For Abrupt Change Raise False Alarms During Sea Ice Loss',  was published in Geophysical Research Letters.

Climate and Ice

 

Broadly speaking, I have a strong interest in general questions of climate dynamics, with a specific interest in polar climates. 

 

I've been working on the question of whether the Arctic climate is stable - in particular why some studies find that we might abruptly loose all the sea ice in the Arctic, and why other studies suggest that we won't.  

 

This research is performed as a postdoctoral scholar at the Scripps Institution of Oceanography where my host is Professor Ian Eisenman.

 

One study on this was published in 2015 in the Journal of Climate. The study is entitled "The influence of spatial and seasonal variations on the stability of the sea ice cover" [pdf]

Land Ice & Icebergs

 

Over the last couple of years, I've been trying to understand better how glaciers, ice shelves and icebergs decay. My interest here is mostly focused on how the ice interacts with the ocean, and how such interactions can speed up or slow down the melt and break up of glaciers or icebergs. 

 

The BBC Science 2-part documentary "Operation Iceberg" (see Media), led us to study the decay mechanisms of large tabular icebergs in detail. Somewhat indirectly, this has so far resulted in three articles, on what we call the 'footloose' mechanism, on up/downwelling around grounded icebergs, and on general life-cycles of Arctic icebergs.

 

I've worked to develop a mathematical model to describe the role that buoyancy forces play in the break-up of floating glacier fronts. The title of the study is 'On the role of buoyant flexure in glacier calving', which was published in Geophysical Research Letters in 2016. 

Most recently I've worked on the drift and decay of icebergs, both in the Arctic and Antarctic, in the present-day climate, as well as during the last ice age. You can find a series of studies on this topic on the Publications page.

Sea Ice

 

During my time as Ph.D. student in the Polar Ocean Physics Group (POP) at the Department of Applied Mathematics and Theoretical Physics (DAMTP) at the University of Cambridge I spent some time looking into the current thickness and structure of the Arctic and Antarctic sea ice covers.

 

This took me on four polar expeditions; more information on these can be found in the blog MenOfIce (that I was writing with fellow PhD student Nick Toberg) and in the Media section.

 

It also gave me the opportunity to spend some time at NASA's Goddard Space Flight Center in Greenbelt, MD, where I was working with the Operation IceBridge Team, looking at airborne LiDAR data collected during Antarctic IceBridge missions.

 

And I had the chance to work with Hanu Singh's Group at the Woods Hole Oceanographic Institution, studying the surface morphology of sea ice in Antarctic spring from airborne imagery. 


 

Solid Mechanics

 

From 2009 - 2012 I wrote my Ph.D. in Cambridge, looking at how thin sheets bend and stick. This is the opening paragraph of my thesis, entitled Elastocapillarity - Adhesion & Large Deformations of thin sheets:

 

This thesis is concerned with the deformation and adhesion of thin elastic sheets that come into contact with an underlying substrate. The focus of this work is on the interplay between material and geometric properties of a system and how this interplay determines

the equilibrium states of sheet and substrate, particularly in the regime of geometrically nonlinear deformations.

 

The earliest four papers listed on the Publications page contain the central results of the thesis. The full version is freely accessible here.

 

The research described in my Ph.D. thesis was performed under the brilliant supervision of Dr Dominic Vella, who is based in OCCAM at the University of Oxford.