Scientist Profile: Uriel Zajaczkovski

In today’s blog update, we spoke to Uriel, who is a PhD student on the UK DIMES 3 cruise. We started by asking him about his background and the research he is undertaking:

I am studying at Scripps Institution of Oceanography under the guidance of Sarah Gille. My research is currently focused on how heat is transported from the equator to high latitudes. In particular, the Southern Ocean circulation plays an important role in the Earth’s climate system by controlling the oceanic meridional (north-south) heat transport in the Southern Hemisphere. Despite this fundamental role, the details of how heat is being transported still remain unclear.

Uriel in the main lab

What is your involvement with the DIMES project?

One of DIMES’s goals is to quantify mixing along and across isopycnals. A suitable coordinate system for the study of isopycnal mixing in the Southern Ocean is therefore needed. Eddy diffusivities via Taylor’s approach can only be estimated for homogeneous and random motions; dispersion effects from the mean shear flow must be filtered out. Otherwise diffusivity estimates in regions of high horizontal shear, such as the Antarctic Circumpolar Current fronts, are expected to behave non-asymptotically at large lags. Therefore the estimation of a robust mean flow is of vital importance in order to achieve stable estimates of isopycnal mixing. For the past few months, I have been working on the estimation of the mean density, temperature and salinity fields of the Southern Ocean by combining in situ Argo float measurements and satellite altimeter data. The percentage of variance captured by the altimeter can be as high as 40% at the density surface where the tracer (dye) was injected. Moreover, the signal to noise ratio shows a substantial improvement. This suggests that when altimeter data are used in combination with in situ Argo float measurements, fewer observations are required to produce a stable estimate of time-averaged density field. 

What do you personally want to get out of this cruise?

I am here mostly for the experience and to learn as much as I can about microstructure profilers. It is also a good opportunity to meet colleagues and find out what they are working on.

What do you enjoy about going to sea and working in oceanography?

Being at sea for long periods of time can be really fun if one has the right attitude, and the possibility to explore remote places is definitely a plus. For me, one of the most exciting things about Physical Oceanography is the fact that it is a relatively new branch of Physics. A lot of controversy still remains in the most basic subjects and our understanding is being re-shaped and broadened every day. These are very exciting times for oceanographers!

Uriel works the evening shift on ship and has taken the opportunity to grab a couple of great sunset pictures. Enjoy!