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!

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

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Posted in Student/Postdoc Blog

Back to school and starting-up the new modelling sensitivity studies

by Laura Castro de la Guardia

When I am ask by friends: What is it that I study? I generally give them the quick answer: I study biological-oceanography at the University of Alberta. But when they look-up “University of Alberta” on Google map for example (Figure 1), they  always point out: there are no coastlines near the University of Alberta! In fact, the province of Alberta in Canada, has NO coastlines at all. So, how is it then, that I can study the oceans?  Although one way will be to spend a lot of time travelling to either western, eastern or northern Canada to do my field work, I can also study the oceans from my own desktop at university!

I use a mathematical model on the computer to create a virtual ocean with some biology and chemicals; it is sort of like a video game, but the model attempts to be as realistic as possible. The core of the model is based on the most current understanding of physical and mathematical relationships that exist between the ocean, the atmosphere, the sea ice and the biology.

There are many models available. The ocean model I used is called NEMO (http://www.nemo-ocean.eu/) that comes together with a sea ice model LIM. The biological and chemical model I used is embedded within NEMO and it is call BLING (https://sites.google.com/site/blingmodel/). Cool names acronyms, right?! Both models are free to use by any user, but it requires some understanding of computing science, programing, and a very powerful computer. We have to run our model on super-computers that are shared across Canada  (Compute Canada/Calcul Canada).

Unlike what you may have imagined from my video game analogy, the output of the model is not a movie, but lots of numbers (a.k.a simulated data). The “simulated data” is what I use to do statistical analysis of many different things, for example, I can see the current state of the ocean, or the sea ice, or the marine algae (phytoplankton). We can also make movies with the simulated data  (e.g. http://knossos.eas.ualberta.ca/vitals/outcomes.html)

Although models are still not able to reproduce an identical ocean to our real ocean, one of many advantages of an ocean model is that I can study how one single event/phenomena/or property in the atmosphere affects my simulated ocean  or biology. This type of studies are called sensitivity studies, and they are like experiments in a lab. This is important because in our current climate, many things are changing at once (for example in the Arctic Ocean, sea ice is decreasing, temperature is increasing, the rate of river flow into the ocean is larger, there is more rain, there are more storms during the autumn), but we only observe the response of the oceans to all changes. While with the model I can have the response of the model to all changes, but also the response of the phytoplankton to only one change (e.g. more storms during fall (Figure 2)). Depending on what I am studying, I can then answer which of all these changes is the most important, which one is the one I should be most concern with? These are the kind of questions I would like to focus on for my sensitivity experiments, because these questions can help us prepare for the changing future: e.g. they could help shape or guide the adaptive tactics and conservation programs.

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Figure1. Google map showing the locations of the University of Alberta, Canada.

 

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Figure 2. A simulation with storms (a) compared to a simulations without storms (b). The differences between each panel shows the regions where the storms have a greater impact on phytoplankton.

 

Posted in News

OSNAP Logo Contest

Calling all OSNAP collaborators and inspired oceanographic community members! OSNAP is looking for a new visual identity and is seeking your help in designing a creative logo.

How to Enter the Contest
The contest begins on October 1, 2016. Submissions will be accepted through November 15, 2016. Winners will be notified, and announced via our website and through social media. In order for your entry to be submitted and reviewed, please follow the details below:

  1. Submit entry to Sarah Clem (sarah.clem@duke.edu)
  2.  Submit the entry in its original source file and
  3. Submit as a pdf with 300 dpi or higher.

Logo Requirements

  • Design: The logo will be featured on our website, on our social media platforms and other media (e.g., research posters and t-shirts). Thus, we want the logo to be eye-catching, but also legible. Also, the logo should be easily reproducible and scalable for large and small formatting.
  • Color: Any colors may be used. However, the logo should look good in color (if used) and in black and white.
  • Integrity: Logos cannot contain copyrighted material. Logos must have been created by the contestant(s). Logos may not include images or licensed images that have been previously published.

Contestant Agreement
The winning contestant must agree that OSNAP can use their logo for future publications and outreach applications. Additionally, the contestant must agree that OSNAP can alter, modify or revise the logo as it sees necessary. OSNAP reserves the right to not select a winner if, in its discretion, no suitable entries are received.

Prize
Contest winner will receive an Amazon Gift Card (and bragging rights!).

Posted in News

OSNAP Challenge

We want to bring everyone’s attention to the launch of the OSNAP Challenge located on this site under News and Events. Anyone is welcome to submit a prediction (or technically a hindcast because the data have already been collected) for the first two years of AMOC data from the OSNAP line. This contest is similar to the one organized by the RAPID program last year but in this contest there are no past observations of the AMOC from the OSNAP line so the level of difficulty is higher!

We are going to open up this blog to write-ups of the methods from each prediction and will be announcing the winners here in the Spring. The deadline for the submissions is April 1st. For more information including instructions on how to submit a prediction and how the submissions will be judged, see the site here.

We wish everyone luck and may the best model win!

-Nick

Posted in News

OSNAP Publication in BAMS

OSNAP collaborators have a produced a new paper for publication in the Bulletin of the American Meteorological Society. An early online release version of “Overturning in the Subpolar North Atlantic Program: a new international ocean observing system” is currently available on the AMS website:  http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0057.1

Posted in News

Home again, with instruments recovered, moorings re-deployed, and data safe and sound

by Penny Holliday

 We’re steaming through Southampton Water on a hot, sunny day, and as we near the dockside at NOC we’re reflecting on a successful and enjoyable cruise.  We were very lucky with the weather, and that, combined with the work by our highly skilled team of people on board, meant that we have achieved all our scientific objectives.  I’m very pleased with the excellent quality of the data that we have collected, and with the new friendships we’ve made.

 The OSNAP moorings are now starting a 2-year long period in the deep ocean collecting lots of precious data for us – and some of us will be back to retrieve them in 2018.  Meanwhile, we’ll be busy analysing the data we’ve collected on this trip, and looking forward to going to sea again.

 DY054 Team Photo

Photo by Penny Holliday

Posted in News

Caffeine consumption among the DY054 science team (The Great Caffeine Experiment)

by Ryan Peabody

Scientists and marine technicians have long appreciated the productivity-increasing role of caffeine [citation needed]. However, quantitative assessments of caffeine consumption and usage among the members of the DY054 science team have not yet been performed. Herein, we perform a not-quite-exhaustive nine-day analysis of tea and coffee consumption on the RRS Discovery. No significant trends were observed, other than a general preference for tea over coffee, and a sharp decrease in enthusiasm for the study as it progressed. Further work is needed to determine whether or not bush tea counts as a cup of tea, and exactly what quantity of coffee counts as a colloquial “cup.”

 Data were self-reported via “marker and whiteboard,” following methods developed in Mrs. Cooper’s second grade class [Cooper et al., 1999]. Logging was originally intended to take place daily at 23:59:59 UTC, but the lead scientist occasionally felt “really over it” and data were not recorded until the following morning. Efforts were taken to ensure that subjects maintained standard patterns of caffeine consumption, though it is worth noting that several believed the study to be a contest to see which one of them could drink the most coffee.

 Coffee and tea consumption demonstrate a general downward trend over the nine days, both passing a Mann-Kendall test (Figure 1). A 0.377 coefficient of cross-covariance implies that coffee and tea consumption are not related at any reasonable confidence level. Tea was consumed in generally higher quantities: on average 2.1 cups/person/day to coffee’s 1.6 cups/person/day. Further study is needed to determine if this is standard on a British flagged research vessel. Initial data supports this hypothesis: American-born members of the science team consumed 2.8 cups coffee/person/day and 1 cup tea/person/day, while British nationals consumed 1.3 cups coffee/person/day and 2.2 cups tea/person/day. The sole Hungarian-born member of the science team consumed an average of 6.1 cups of tea per day and 0 cups of coffee.

 Over time, a noticeable lack of enthusiasm for the study is evident, with participation dropping from 14 initial participants on day 1 to 6 participants on day 9 (Figure 2). On a ship with 45 crew and scientists on board, this represents a drop from “low” to “very low” participation. Despite the decrease, 70% of participants reported feeling “fair” to “good” about their own caffeine consumption and the study, indicating that maybe no one was really paying attention to the study in the first place. A least-squares fit of a nonlinear model of form b(1) + b(2)*exp(b(3)*t) represents the data very well, but also indicates that it was wise to end the study on day 9 (Figure 3). If the study had continued until the scheduled arrival in Southampton, approximately -15.5 responses would be logged each day, indicating that study participants would begin to erase the previously collected data, invalidating the entire study.

 Clearly, further study is needed to determine: 1) exactly how much caffeine is being consumed on board, 2) why no one wants to log their daily caffeine consumption, and 3) whether or not this was a good use of my time. Caffeine is a widely-consumed but little-studied product in the context of oceanographic research vessels, with most scientific effort going toward measurements of physical, chemical, and biological properties of the ocean. Though oceanographic research vessels are built and used primarily for the latter three areas of research, there is no apparent reason not to also study caffeine consumption.

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Images by Ryan Peabody

 

Posted in News

Life at sea: stories from the night watch

by Sotiria Georgiou

 Here we are! 15 days on board! So far, 36 CTD stations, 10 Moorings, 25 RAFOS floats and 1 Argo float have been completed and so many stories to tell!

 Back on land, I am a PhD student at TU Delft in the Netherlands. I am using a numerical model to reproduce the circulation of the Labrador and the Irminger seas. To validate a numerical model we use observational data that we can easily download from the web. That means that we want to be sure that the output data of the model are able to reproduce the real state of the ocean as well as possible. Being here, in the Irminger Sea, collecting data for the first time is a priceless experience. Now, I get a rough picture on how complicated is to plan such a cruise to obtain the precious data and keep track on it whatever difficulties might occur. 

 The team is working hard during day and night. Me and Ryan are the night-watchers. During the night the ship is quiet and everyone is waiting for some action. That’s going to be either by getting to a CTD station or by releasing some RAFOS floats. When we reach at a CTD station the technicians will guide the CTD from the deck to the sea surface and then all the way down to the bottom. Once it returns on deck, we make sure that all the bottles keep well protected the water from the different depths. Then, under the whispers of songs (mostly from the top 40..), we take water samples from each of the bottles for both salinity and nutrients. Even if is too dark to distinguish the difference between the ocean and the sky, there is a beautiful sunrise to wait for (not everyday though!!).

 Yesterday, we had some celebrations! Anna turned her 21st year! During the dinner (having greek mousaka!!) there was a big surprise for her. A huge birthday cake suddenly popped up from the kitchen followed by the happy birthday song! Mia made a wonderful birthday card for her and we all wrote our wishes to her. She was really happy! 

 We are about to finish the measurements and then we need almost one week to sail back to Southampton. On our way back, as we will all be more relaxed, there will be time to discuss the first processed data, our research and have even more fun!

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Birthday cake

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Chefs cake

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CTD and float

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Ryan and CTD

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Sunrise

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Photos by Sotira Georgiou

Posted in News

Blog 2 from the Neil Armstrong

Tonight, during our 2000-0400 shift, my watch-mate and I are feeling like Neil Armstrong; walking into the dark to achieve a better knowledge of the unknown. As we approach our next station, the whole ship shakes due to the high winds and waves, as a spacecraft does on its way up, but more harmonically. After all, the Saturn V had a speed of 21,785 knots while ours is 10 knots; and, while it took Neil Armstrong’s spaceship only 3 days to arrive at the moon, we would take 755 days. Anyway, with this shaking one cannot avoid remembering the lyrics of the serenade from the Steve Miller Band: “Did you feel the wind/As it blew all around you”.

Strong gravitational forces can be felt when going down the steep vertical stairs in these waves, where one must be careful not to fall in front of Neil Armstrong’s picture and make a fool of yourself. When we get out to sample, it is as dark and cold as it probably is in space, but here we also have the wet component.  The deep ocean, like space, is one of the least explored areas scientifically and, as such, is also a hostile environment for mankind. Around 2500m depth, water temperatures hover around 1ºC and the pressure is enough to convert a foam coffee cup into a little shot glass. Unlocking the mysteries of the ocean requires a big passion for science – as is true for space exploration.

All of a sudden, from the porthole, in the far distance a tiny light appears. It is not a satellite; it shows the position of another ship in this immense solitude of water. It is 0200, and all you can hear is the engine (and some background music in the main lab). We two astronauts of the ocean are launching the rosette into the deep; we also wear a helmet and boots, but instead of a space suit we use a personal floatation device. [The rosette contains a CTD, which is a sensor that measures conductivity (to estimate salinity), temperature and depth; a LADCP that measures the ocean currents using sound (the Doppler effect); and 24 bottles of 12 litters each to capture water at different depth. This collection of instruments is deployed from the surface to 10 m above the bottom, which takes hours to do.] Perhaps our real space suit is the immersion suit (affectionately known as a gumby suit) and is only reserved for ship-evacuation cases – designed to secure survival in this hostile environment.

As morning arrives the vessel’s common areas start to fill with people and the vessel no longer has the lonely feeling of a space craft (luckily!).

SaturnV

Posted in News

Photography at sea; teamwork and capturing the moment

by Amanda Kowalski

One of my greatest joys in life is people watching, and fortunately my role on board requires me to do just that. As the cruise photographer I spend most of my time watching and waiting for the best moment to click the shutter button. At the beginning of nearly every job I feel a bit burdensome and uncomfortable, but everyone on this ship has made me feel particularly at home. Consequently, I’ve been happily, and sometimes clumsily, snapping away during most deck operations.

 Though I find myself tripping on cables and occasionally hitting my hardhat-clad-head on various pieces of industrial equipment, I’m truly amazed at how gracefully the technicians on deck execute their jobs. They know the routine of each operation so well that they anticipate one another’s moves and effortlessly maneuver hundreds of pounds of gear. My two favorite technicians to photograph are Steve and John.

 Steve and John are the two men who work at the edge of the fantail, guiding and sometimes pulling in the enormous buoys, chains, and fragile scientific sensors that comprise the moorings.  The deck is noisy, but the two know one another’s moves so well that there seems to be little need for conversation. One moment they are using brute force to hoist in a chain of buoys that’s gotten stuck at the edge of the ship, and the next moment they are nimbly untangling a sensor from the line. Time and again I watch as John gently holds an microcat while Steve carefully unscrews the bolts that have anchored it to the line. Though there is a clear routine to the work, small surprises and dilemmas abound and the pair handles each one with care but without concern. If words are exchanged at all they usually seem to be in the form of a joke.

 I had the good fortune of sitting down to dinner at the same time as Steve a few days ago. He told me that he has been at this for thirty years. That made me reflect on my job. Will I still be as committed to my work in thirty years? I think so, but I can only hope that I achieve the same level of ease and expertise as he and John clearly have.

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John and Steve with the anchor chain

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Steve and John

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Steve and John

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Steve

 

Photos by Amanda Kowalski

Posted in News

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