Aleksi Nummelin

I am physical oceanographer and climate scientist based in Helsinki, Finland. I have keen interest in numerical modelling and new approaches to data-analysis. Also, Python.

BIO

I am tenure-track research professor at the Finnish Meteorological Institute (FMI; since August 2022) and a senior researcher at NORCE Norwegian Research Centre AS. At FMI, I am currently working towards a coupled NEMO-HCLIM regional climate model setup. As part of my position at NORCE, I currently work with the team developing the Norwegian Earth System Model, which I am applying to questions of past, present, and future climate. Until summer 2022 I also worked as an adjunct researcher at the department of Geosciences at the University of Oslo, and I still continue the collaborations under Norwegian Research Councilt funded project TopArctic and DOTpaleo projects, focusing on eddy-topography interactions, and ocean circulation under extreme warm climates, respectively.

My main research interest are high latitude climate and ocean dynamics. In terms of the high latitude climate, I am continuing some of the work started on my PhD, trying to understand why there is such a large model spread on future projections of high latitude climate (e.g. Gjermundsen et al. 2021; Muilwijk et al. 2022). In terms of ocean dynamics I seek to understand how the mesoscale eddy field affects the ocean and climate system, and especially how those effects can be parameterized in global coarse resolution models where eddies are not resolved. To this end I have worked with estimating eddy mixing from satellites (Nummelin et al. 2021), developing theoretical parameterizations (collaboration with P.E Isachsen at UiO), and most recently, parameterizing the sub-gridscale diffusivity with machine learning algorithms (on going proposal).

I am originally from western Finland, and I did my undergraduate studies in the department of Physics at the University of Helsinki. For my master's and bachelor's degrees I worked with Bert Rudels. During my studies I also worked at the marine research department in the Finnish Meteorological Institute (FMI), and I had the possibility to participate on research cruises as a part of the EU THOR project. At the time I also worked with the first ever ARGO deployments in the Baltic Sea.

For my thesis work I moved to Bergen, Norway, to work with Camille Li, Lars Henrik Smedsrud, and Bjørk Risebrobakken. My thesis was part of the DYNAWARM project at the Bjerknes Centre for Climate Research, and I also had the chance to work with the ice2ice project towards the end of my PhD. I graduated with a PhD in climate dynamics on 2016 from University of Bergen.

After my PhD I moved to Baltimore (US) to work as a postdoctoral fellow with Thomas Haine in the Department of Earth and Planetary Sciences at the Johns Hopkins University. My postdoc was focused on developing an inversion algorithm that takes an oceanic tracer field (such as temperature, or salinity), and estimates kinematics related to the underlying flow field (anomaly propagation speed, tracer diffusion, and decay timescale). The code is available at github.com/AleksiNummelin/MicroInverse.

Contact

If you are interested in collaboration, or have questions of any of my papers or code, please send me an email

aleksi [dot] h [dot] nummelin [at] gmail [dot] com