Category Archives: Student/Postdoc Blog

What I love in observing the oceans

by Loïc Houpert

So today, I decided to contribute to the blog by telling you what I like in my work as an observational physical oceanographer.

I am working as a postdoc at the Scottish Association for Marine Science in the beautiful and “occasionally” wet town of Oban. Being a physical oceanographer, I am generally interested in understanding the ocean’s circulation, but right now my interest is more focused: how is the ocean’s heat carried by the currents in the North Atlantic and where is this heat going? The transports of heat and also freshwater by the North Atlantic current system are particularly important for the temperature, precipitation, and wind patterns and strength over the European continent. In my research, I am using autonomous instruments (underwater glider and fixed instrumented lines) that continuously record the state of the ocean.

Going at sea to take measurements and deploy/recover instruments is definitely the best part of my work, although stressful at times. But after coming to shore, the most interesting part of the job is to actually unravel all these big datasets and try to identify physical signals that are associated to the dynamic of the ocean. In addition to having good knowledge of physical oceanography, several factors are important when working on observations: curiosity (being interested in seeing buy ambien online what is in the data), imagination/intuition (finding a way to put together the different pieces of the puzzle) and of course a little bit of skepticism (test the results’ robustness again and again …!).

I really choose to become an observational oceanographer in the second year of my Master, during my research project. It’s true that I had some second thoughts after my first sea-going experience as I was very sick for most of the time of this 7-day cruise… However, 8 months later, during my PhD, I took part in my second cruise and everything went (surprisingly) well. Of course some days were more bumpy than others, but at the same time, this 3-week cruise was in the middle of the Gulf of Lions in winter to sample the impacts of strong storm and deep (2000m) vertical mixing on the marine ecosystems…. All of this to say that you should never stay on a bad first experience when going at sea. Tenaciousness… this is also a good quality if you want to analyze ocean observations!


Illustration 1: Myself blinded by the sun taking a (bad) selfie with Estelle, Karen (the two SAMS glider experts) and Bowmore (the pink glider) after its recovery on the DY053 cruise in July 2016, over Rockall Plateau.


Numerical models, in-situ data and research cruise plans

Tillys Petit, PhD student (who also enjoy the view from my office, figure 2)

Nowadays, numerical models are increasingly used to understand and predict climatic issues such as global warming, rising sea level, or shift of oceanic circulations. To answer those questions, numerical models compute a collection of data from an initial setup, allowing us to first visualize the actual state and then the evolution of the temperature, sea level or oceanic circulation around the world. But how can we know if the output is/will be in agreement with the reality? To validate a numerical model, we still have to compare the actual state given by the model with its in-situ observations. But in-situ data are still too often lacking, and cruises are thus carried out. The new set of data is firstly analysed to document the general circulation and to identify new mechanical processes, and secondly used as benchmark for models.

Currently my work is to document the oceanic circulation across the Reykjanes Ridge (South of Iceland) where very little data is available. A strong current-bathymetry interaction could impact the circulation, hence the need for better understanding of this process. To fill this gap, a cruise (RREX) was carried out in June 2015 and another is planned in July 2017. During the 2015 RREX cruise, a lot of new in-situ data were obtained along 4 sections (figure 1), such as velocity of the flow and salinity-temperature-oxygen profiles. Moorings were also deployed and will be recovered during the second cruise. Up to now, I have studied the data of the first cruise, which are of good quality, allowing us to fully address our scientific objectives. Because I was not on board in 2015 I cannot tell you how the cruise was, but I will certainly keep you inform of the general ambiance during the second!


Figure 1: Map showing the hydrological station locations during the RREX cruises.