by Greg Siddall

Introduction:

The VITALS (Ventilation, Interactions and Transports Across the Labrador Sea) research network is funded to study how the deep ocean exchanges carbon dioxide, oxygen, and heat with the atmosphere through the Labrador Sea. To address this topic, a multi-instrumented, deep-ocean mooring has been deployed to measure and collect oceanographic parameters in the Labrador Sea.

The mooring contains a surface-profiling “SeaCycler” at its top, with 9 x MicroCAT CTD’s and two RDI ADCP’s below it. SeaCycler is ideally suited for VITALS research due to its unique ability to profile the upper ocean making numerous simultaneous measurements near the surface.

The deployment was very successful and early engineering results are encouraging.

At the time of writing, SeaCycler has completed:

• 12 profiles to the surface from a parking depth of 154m,
• Is moored in 3526m of water located mid-way between Greenland and Newfoundland, Canada,
• Has sent 72 data files to shore,
• and has profiled a total vertical distance of 3.3 km underwater.

Unless new commands are sent, the system is programmed to profile every 20 hours for the next year.

The average water temperature in the upper 150m is currently 3.9 °C.

SeaCycler – A Short Description:

Fig 1, SeaCycler Mooring Components

SeaCycler is a moored, deep-ocean, surface-piercing profiler with two-way satellite communication. This means it’s anchored to the sea floor and cycles (or “profiles”) oceanographic sensors through the upper 150m of the ocean collecting measurements on the way (see Fig 1).

At the top of the profile, it surfaces a satellite telemetry system to transfer data to shore and receive new commands. After communication, it returns its profiling elements to a depth resistant to bio-fouling and safe from surface hazards such as ships and storm waves.

Primary to SeaCycler’s success is its ability to profile a sizable sensor suite (currently 11 sensors) using substantial buoyancy to resist mooring knock-over from ocean currents while conserving battery-stored energy to permit over 500 x 150m profiles throughout year-long deployments.

SeaCycler senses surface conditions and will abort profiles prematurely if wave loading exceeds an adjustable limit.  Profiling movement is controlled by a unique drive system which powers an underwater winch that has built-in compliance and no rotating seals or slip-rings to enhance reliability.

Deployment Description:

The weather was good with light winds and 1 to 2m waves. We started early in the day as winds were forecasted to pick up. A quick site survey revealed flat bathymetry and good water depths.

SeaCycler components were deployed in the usual “MechFloat-tow, CommFloat, SensorFloat, MechFloat-slip” fashion (B-L of Fig 2), which worked well.

MechFloat-tow, CommFloat, SensorFloat, MechFloat-slip

double-anchor

SensorFloat

MechFloat

The buy ativan online A-Frame was used to deploy most mooring components including the MechFloat. The CommFloat was slipped by hand and a slewing crane deployed the anchors.

A capstan winch was used to pay out cable and deck cleats were used to slip mooring loads.

The deployment took less time than expected and resulted in an estimated 3-hour tow to achieve station. It was decided to omit 1 x 5m length of chain and deploy immediately to avoid the long tow. The final mooring location was about 2 nm further from the AR7W line than originally planned.

The ship was maneuvered to follow the mooring’s top floats until they submerged. A nice gentle tow was observed. No mooring beacon hits were received after submergence.

Fig. 3, Mooring top floats being towed by a sinking anchor.

Hydro-acoustic triangulation was not performed at this time and instead, the ship was relocated for K1 deployment. The ship returned to the SeaCycler site later that evening, but triangulation was not performed since a SeaCycler surfacing had already occurred providing a more accurate GPS location fix.

Mooring Position & Anchor Fall-Back:

The 2400kg double-quad steel anchor was slipped in 3526m of water and eventually settled on the bottom 1016m to the South-East.  It took 38 minutes for the top of the mooring to submerge after anchor release. This equates to a SeaCycler descent rate of .48 m/s, which is well within acceptable limits.

The final mooring position is determined by averaging CommFloat GPS location fixes shown in Figure 4. The central “Best” point indicates the profile with least amount of “Extra Cable Out”.

Fig 4, CommFloat GPS locations for the first 10 profiles

Acknowledgements:

The entire SeaCycler Team at Dalhousie University and Scripps Institution of Oceanography would like to thank the Maria S. Merian’s Captain Ralf Schmidt for his support and excellent ship handling skills and our Chief Scientist, Dr. Johannes Karstensen from GEOMAR-Kiel for his support and acceptance of our operation into his OSNAP West project. We also acknowledge the support of the VITALS project of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Excellence Research Chair in Ocean Science and Technology for supporting this deployment.

Many thanks are also given to Christian Begler, Gerd Niehus and Uwe Papenburg for their valuable advice and help on deck and to the many students and ship’s crew for their excellent mooring handling skills and provision of delicious food.  

It was a pleasure to meet and work with the entire MSM54 team. We sincerely thank you for your help and assistance and opportunity to sail together.

New SeaCycler data is reported daily Here

by Marilena Oltmanns

56°N, 52°W. For days we have been cruising around these coordinates, and no matter whether we are some sea miles further south, north, east or west – the view does not change much. Even so, the ocean looks different every day.

I am on board the Maria S. Merian as a postdoc from GEOMAR and particularly interested in the mooring data from the central Labrador and Irminger Sea. In these regions, the ocean and atmosphere permanently exchange heat, with consequences for both sides. If, for instance, a cold winter storm cools the ocean, the surface water is getting colder and therefore denser, making it sink to the bottom. In reverse, the atmospheric circulation is affected by the sea surface temperature, which can give rise to complex ocean-atmosphere interactions. In my research, I am particularly interested in the uppermost water layer which serves as a bridge between the atmosphere and the deep ocean and thus buy valtrex online forms a connection between our weather and climate.

Photo: Henrike Schmidt

Photo: Henrike Schmidt

Photo: Henrike Schmidt

Photo: Arne Bendinger

In the middle of the Labrador Sea, somewhere near 56°N, 52°W, I watch the waves breaking around the ship. Water and air seem to intermingle and I imagine them carrying the icy winds down into the during a heavy winter storm. At this location, exactly below my feet, the ocean is almost 4 kilometres deep. Water this deep will need a long time to reemerge at the surface. Maybe some centuries. Maybe somewhere near Antarctica. Space and time are intertwining here, just like the days and nights on board the Merian. The depth and vastness of the sea evoke a feeling of timelessness and right in the midst of all this water, I am feeling quite small.

by Sijia Zou

Figure 1: Mooring launch locations (white squares at 53N array, the central Labrador Sea and west Irminger Sea) and CTD stations (small yellow squares). This picture is from Johannes Karstensen (chief scientist of the cruise) with permission.

Another promising year for measuring Atlantic Meridional Overturning Circulation starts with cruise Maria S. Merian 54 (MSM 54), which departed St. John’s, Canada on 12^th May and will end on 7^th June in Reykjavik, Iceland. During this cruise, we will deploy seven moorings at the exit of the Labrador Sea near 53N, and two deep ones at the entrance near the west Greenland coast (Figure 1, right). These moorings serve to measure the magnitude and variability of the deep western boundary current as well as the connection of deep layer transport between entrance and exit of the Labrador Sea. Besides, direct measurements of the convective activity will be accomplished with mooring deployments in the central Labrador Sea (K1 and SeaCycler) and the central Irminger Sea (CIS). These observations will collectively contribute to our understanding of how the boundary current (both strength and property) varies with time, and the how these buy kamagra online changes are related to the convections.

Along the cruise, we will be conducting 90 CTD casts, crossing the Labrador Sea and west Irminger Sea. We are excited to expect a thick, cold and fresh Labrador Sea Water layer comparable to the ever-observed deepest convection in 1994.

Now we have been at sea for 5 days. The weather was not as good as what I have hoped: it was windy and cold during the first 3 days and got foggy afterwards. Hopefully the weather is getting better so that we can have everything progressed as scheduled.

Just BTW: Food is great on MSM (Figure 2). People are nice (Figure 2). I wish I could speak some German.

At the port of St. Johns, Canada on May 12th before cruise started. by Sijia Zou

With two other students (Christina Schmidt on the left and Patricia Handmann on the right) from GEOMAR (photo credit to Marilena Oltmanns). The flying hair in this photo tells you how important it is to wear a hat on the ship.

One of the great dinners on board (half chicken!!).

by Johannes Karstensen, chiefscientist MSM54 expedition

 The ocean-class German research ships are rarely seen in Germany. They follow a route that is composed by many individual expeditions and converting the ships travel into a long, long journey; for Maria S Merian this journey takes place primarily in the North Atlantic and it transition into the Arctic Ocean. As a consequence – the scientists have to travel to where the ship is and have to bring with them (again by ship, but container ships) the equipment that is needed for the experiments to be performed at sea.

Without equipment brought by the scientists the Maria S Merian is not at all an empty ship – she carries a lot of equipment, required by almost all groups that make use of the ship, such as cranes, work shops, communication devices, instrumentation. However, most important – the ship is manned with a skilled, experienced and simply great crew, providing all support to not only conduct experiments at sea but to find a comfortable atmosphere which makes life at sea easy for us, the non-seamen.

In the last ten years I have been six times to St. Johns, Canada – all times to enter a ship (two times the Maria S Merian) for expeditions to the Labrador Sea. Typically I arrive 3 to 4 days before the cruise starts, just to be here when the ship arrives and to help loading and setting up equipment. The arrival of the ship is always special; for example people often eagerly wait to be back to shore, leaving the steadily moving platform behind – but to discover that the movement continues even on land for the next couple of days. St. Johns is a convenient harbour for us, just 1.5 days transit to one of our main working areas (the “53°N array”) – but it is also a nice little town settled around a large natural harbour bay.

Caption: View from Battery Park on St. Johns harbour. The two research ships (easy to identify by the “A” formed crane mounted at the stern, are the Irish Celtic Explorer (keft) and the German Maria S. Merian (right). credit: J. Karstensen

We, a science crew of 20 people, need for the installations and experiments planned during this trip (called MSM54) an amount of material that came in 7 containers. We fixed 4 containers to the ships deck but the rest of the material is now distributed in the labs.

The science crew is composed of five people from Canada’s Dalhousie University, one person from Duke University in the US, and 14 persons from GEOMAR in Germany. We are a mix of students (9), from PhD to BSc, technicians (7), and full scientists (4). A lot of the work that will be done is very technical – installing quite heavy equipment that ultimately serves us to conduct our experiments at sea generating data that is of use for our scientific investigations. What we are really after is to better understand how our ocean regulates climate – for example by taking up heat and other substances in specific regions, such as the Labrador Sea, where large amounts of near surface water sink to sometime deeper than 2000m depth, and from where it spreads far into the ocean interior.

What regulates the sinking process and how does the water spread in the ocean interior are some of the questions we want to answer. The 53°N-Array has been first installed in 1997, long before I came to Kiel to work in this region. It is a unique time series not only because it is operational since so long, but because it has been well designed from the beginning. Setting up a time series has similarities in buying a house – the only thing that matters is the location!

On this trip we will recovery many instruments that were installed during the last service of the array in 2014. For that cruise we started, guess where? – in St. Johns, correct! but on the French Research Vessel NO Thalassa. Not only the two of us who participated in the Thalassa expedition are now very excited to see how well the instrumentation had worked over the last two years. In 2018 we plan to come to the Labrador Sea again to service the “53°N-Array” – and I hope I can one more time join the long, long journey of the RV Maria S Merian.

Credit: C. Schmidt

‘Go with the flow’: Research on the currents in the subpolar North Atlantic

This past July chief scientist Laura de Steur and the crew of the Pelagia set out to take measurements of the subpolar gyre as part of NACLIM and OSNAP research programs. Research conducted on this cruise, and as part of these programs, is important in understanding the “role of the ocean in our climate and future climate change.” Learn more about their work this summer, and ongoing research, in this film created over the course of the cruise.

 by Huang Lei

OSNAP 9: R/V Pelagia (EAST Leg 2)

My pleasure to join the OSNAP cruise on Pelagia, to meet kind friends from Europe and America who devote themselves to marine career, to experience series of interesting survey. Along with the days on sailing, it’s not only the difference in culture and tradition but also their passion on oceanology with heart that shocks me. In spite of the same survey to sail in Pacific, there seems to be something lost as pursued years ago, the curiosity to explore the uncertainty.

At occasional glimpse on the patience to ADCP of Dave,  the worry about the calculation on Julian Days of Laura, the preciseness on CTD from Ruud and Karel, and the excitement with photo of Pluto buy tramadol online from NASA in Maarten, I can feel the deep charm of scientific spirit, which roots on the sweat spilled on the way to pursuit for truth. It cannot be measured with material things unless the Tao in Chinese tradition. Road is so long coming that I will seek to search with my will unbending.

????

???Pelagia?

By Huang Lei on Pelagia

???????

Narrow words could be recognized as curved on the cloudy screen

???????

Slim letters spread with wind like mails

???????

Soft waves in the sunshine blinked

???????

All these would make no disturbance to my mind unless the northern breeze blew over my grey temples.

Welcome to Qingdao. Please email to me as you occasionally pass by Qingdao.

Email?hfhhfh241@sina.com hfhhfh241@2980.com

Address: Ocean University of China ?????????238??????? ??

By Laura de Steur

OSNAP 9: R/V Pelagia (EAST Leg 2)

Leg 2 will service 12 moorings: G: the Dutch moorings, D2: British moorings, C: German mooring, L: Dutch profiling mooring, and E1 and E3: RAFOS float deployments

After a bright sunny day of loading and getting ready on RV Pelagia in the port of Reykjavik, we are well underway to retrieve and redeploy 12 tall oceanic moorings in the Irminger Sea (marked with leg 2 in the red box). The successful team from leg 1 arrived in Reykjavik two days earlier than planned and they handed the ship over to us. The moorings we will be recovering have been collecting continuous measurements of temperature, salinity and currents in the Irminger Sea for a whole year. We expect to arrive to the first mooring site on the Reykjanes Ridge on Friday morning to start recovery and read the first data sets from the instruments. After that we head west to collect all 5 moorings on the Reykjanes Ridge and traverse back again whilst doing CTD measurements and float deployments on the ridge after which the moorings will be deployed again for another year.

The mooring data collected during this cruise contributes to both the OSNAP and NACLIM programs. We have an international team with 7 different nationalities. Some of us have to get used to being at sea while others appear to have no problem to focus on computer screens… the weather so far is great though we are expecting more wind and waves tomorrow.

Stay tuned for updates!

Loading of RV Pelagia in Reyjavik

by Bill Johns

Under glorious blue skies and with a fair tide running behind her the R/V Pelagia left the Port of Southampton, England on June 16th to officially begin the OSNAP field season of 2015. The two main science teams joining the cruise, from the Scottish Marine Institute (SAMS) led by Dr. Stuart Cunningham, and from the University of Miami led by Dr. Bill Johns, had been busy unpacking and preparing moored instruments at the National Oceanography Centre in Southampton for the previous several days in anticipation of the ships arrival. Also aboard are scientists from Woods Hole Oceanographic Institution and the Ocean University of China who will deploy a number of RAFOS floats and a glider along the OSNAP East line. After an efficient loading operation the ship was underway through the English Channel, around Lands End, and then northward through the Irish Sea to the first work area off the Scottish coast in Rockall Trough.

The planned cruise track of PE399. Red squares mark mooring locations to be recovered and redeployed; yellow dots represent CTD stations with lowered ADCP. The cruise departs from Southampton UK and ends in Reykjavik, Iceland.

Continue reading →