Andrew Meijers

Biography

Raised in Hobart, Australia, I first became involved with oceanography and the Southern Ocean in particular in my honours year at the University of Tasmania, Australia in 2004. My work there with high resolution models led me into my PhD, also at UTas, supervised by Nathan Bindoff (UTas) and Steve Rintoul (CSIRO). My PhD focussed on using a novel combination of altimetry and insitu hydrography to examine the full time evolving 3D structure of the Antarctic Circumpolar Current. This technique allows the removal of the dynamically less interesting meandering and eddying of the current, which dominates its variability, to examine more climatically critical trends. During this time I also had an opportunity to participate in two Antarctic research voyages on the Aurora Australis (BROKE-West, 2006) and SIPEX (2007), spending a total of 18 weeks at sea. These voyages definitely contributed to my fascination with the region and a determination to become an observational oceanographer. Following my PhD, I took a short postdoc with Steve Rintoul at CSIRO looking at water mass export from the Antarctic continental shelf, followed by taking a Office of the Chief Executive post at CSIRO (Hobart) with Trevor McDougall. Here I used inverse techniques to examine mixing within a tracer contour/neutral density framework. In 2012 I was offered at post at the British Antarctic Survey in Cambridge, UK and gladly took it up. Moving my family and life from Tasmania where I had grown up and worked all my life was hard, but ultimately worthwhile. Since being at BAS I have taken part in two voyages in the Scotia Sea, leading one, and assumed leadership of the Open Oceans team within the Polar Ocean group. My work has expanded to include the examination of coupled climate models, focussing on the Southern Ocean, ocean thermodynamics, mixed layer and subduction processes and shelf export.

Research Interest

Southern Ocean dynamics, particularly ACC overturning and property trends. In particular I make use of property following techniques such as Gravest Empirical Modes to reduce aliasing. This technique takes advantage of the equivalent barotropic nature of the ocean and allowed me to separate the observed trends over the last few decades into adiabatic (due to water mass movement) and diabatic (actual changes in water mass properties) components. Coupled Climate model analysis. Particularly understanding trends in the Southern Ocean. Coupled climate models do a fairly poor job of representing the Southern Ocean dynamics, particularly the overturning circulation. By understanding the reasons for this, I hope to improve both our estimation of uncertainty in overall climate variability and also improve the representation of key processes within the Southern Ocean. In particular I am interested in the potential that machine learning holds for identifying non-linear or unexpected relationships between variables within coupled climate models, and therefore helping us understand how the complex dynamics of these models relates one system to another. Export of dense shelf water and Antarctic Bottom Water from Antarctic, particularly the Weddell and Scotia Seas. This is a water mass that allows long term sequestration of atmospheric properties, such as heat and carbon, in the deep ocean interior. However, it is formed by very regional air-sea-ice processes in the presence of ice shelve, complex bathymetric considerations and is therefore susceptible to change in response to climate forcing. Understanding both how these water masses are formed and how they may change in the future, both via observations and modelling is of great interest to me.