Nights on a research vessel

A research cruise is a twenty-four hour operation. Some instruments, like the SeaSoar, need constant supervision. This means the operators have to work in shifts around the clock. Other measurements have to be taken at a specific time of the day, and sometimes the schedule changes quickly and people need to arrange a spontaneous recovery of an instrument.

Night on deck of the SARMIENTO

Kintxo and Miquel check the APEX float before the deployment

Nonetheless there are moments to relax and enjoy the views of the deep blue ocean at day or gaze at the white moon reflecting of the black sea surface at night.

The nights on the vessel are impressive. The sky is usually clear and there is nothing around us that emits light, except for the ship. The perfect opportunity to sit on deck and watch the moon and stars while the ship gently rocks on the waves.Yesterday we had full moon and the views of the moon are simply fascinating at night.

The moon light causes a halo in the night sky

Visitors on the open ocean

The ENDEAVOR

To meet other ships up close is rare on the open ocean. This made the rendezvous between the American ENDEAVOR and the Spanish SARMIENTO a very interesting change of the daily routine. Since SPURS is an international cooperation, the chief scientist Ray Schmitt, Chris Duncombe-Rae and Julian Schanze climbed in the zodiac and navigated to the SARMIENTO under the eyes of scientists and crew on deck, who were watching the ENDEAVOR up close while the visitors were approaching.

Watching the visitors

The guests are all SPURS veterans from the R/V KNORR cruise in September 2012 and everybody was eager to share initial results and discuss the further planning.

But first the guests were shown around the spacious SARMIENTO and introduced to the captain and officers. Over dinner and coffee the further approach for the mission was discussed.

While the ENDEAVOR will be busy with recovering and maintaining instruments until the weekend, we will start another SeaSoar deployment in hope to find a fresh intrusion like the one we saw on the Southern end of the first SeaSoar sections. This will provide an opportunity to deploy instruments from both ships and map the region around the feature. Helping us to understand how freshwater is carried into the region and eventually enhanced in salinity again, due to exchange of moisture to the atmosphere.

Sarmiento Update 13-03-27

From Chief Scientist Jordi Font:

Last night we started releasing Luca's drifters (#114956, 114955, 114905, 114906, and a triplet 114814-114952-114911). We deployed again ASIP near to WHOI mooring and are now steaming south towing SeaSoar according to the strategy agreed yesterday in the joint Sarmiento-Endeavor meeting. Find attached a figure with release positions and planned SeaSoar track.

The rest of drifters will be released in the forthcoming days, using the time intervals between ASIP deployments.

On Wednesday we also deployed an Apex float in 24.702 -38.146 to perform shallow cycles (200 m). It has not been notified to the Argo system as we intend to use it in short deployments. We will send its positions in order to be included in the overall SPURS positioning data set (even it only surfaces for a few minutes every 4 h). We plan to pick it up on Saturday, after ASIP for a joint deployment on Sunday in the low salinity area in the SE that we are now going to map.

You can see many pictures in our ICM blog http://www.icm.csic.es/icmdivulga/ca/campana-spurs-03.htm (translated version)

Regards,

Jordi

Floating Tupperware

“Why did someone tie a garbage bag to a piece of Tupperware and an oversized Styrofoam doughnut?” some cruise ship passenger might ask if they pass by the SPURS area. 

Acceleration sensor from below (Photo: Anonymous)

There is no doubt that a lot of the instruments we deploy look quite strange. But in oceanography it is all about the inner values, the sensors that provide us with information to understand how the ocean works. In this case the garbage bag is a drogue, which ensures that the float attached to it follows the surface currents of the ocean. The Tupperware is a waterproof GPS antenna for exact position data and the doughnut is an acceleration sensor, which can be used to infer energy input into the ocean by the wind and waves. 

Simon Morisset prepares his surface drifters

The system was developed at LOCEAN in Paris and Simon Morisset takes care of the deployment on board.

There are lots of different autonomous platforms involved in the SPURS program. Surface Drifters of various kinds, profiling floats and gliders provide a great coverage of the area both in time and space independent of the ship.

Kintxo Salvador and Miquel Rosell prepare the drifter

On the SARMIENTO we deployed three additional types of autonomous instruments additionally to Simons surface drifters. One APEX float which profiles the water column and a different kind of surface drifter that measures gradients in the upper meter of the water, using three tightly spaced sensors that record salinity, temperature and pressure every second. Then there is also the ASIP (AirSeaInteractionProfiler), which measures turbulence in the upper ocean up to the surface.  More on this instrument later…

All these instruments need to be recovered after deployment. Which should usually not be to hard, since all the instruments send out precise positions via satellite. But the ocean is not a controlled lab environment and sometimes things can go wrong…

Then the odd looks can actually come in quite handy in order to locate a tiny instrument on the open ocean between waves and sun glint.

A Beautiful Day to be an Oceanographer

Pictures from Julian Schanze on the Endeavor, March 26, 2013

A critter crawling around in some sargassum

Flat calm and glassy seas

Sargassum

Graduate student Alec Bogdanoff returning the above-pictured sargassum to its home in the sea. Behind him are wavegliders being transported home. In front the tip of one of the recovered seagliders.

Endeavor Update 13-03-27

From Chief Scientist Ray Schmitt:

3/27/13 update from Endeavor:

Today the weather was perfect.  No wind, glassy smooth ocean, sunny but not hot, beautiful sunrise and sunset, then a full moon.  And there are hurricane force winds in a huge low pressure system far to  

the north. We certainly chose the right spot to do oceanography!

Today we recovered a wayward Seaglider (at breakfast), a mixed layer float (at lunch) and the wandering NOAA mooring (at dinner). Perfect conditions for finding small targets, for small boat operations, and easy recovery of all instruments.  Only downside was a few folks missing meals because of the timing of the recoveries, but nobody is going hungry on this ship, Archie serves up great food every day.

Tonight we will do Underway CTDs back to the north, then we will spend Wednesday collecting microstructure profiles near ASIP and the two micro-gliders Helo and Saul, which have been following ASIP as it is carried west of the WHOI mooring.

There was strong surface diurnal warming of about 4 degrees C, and a surface salinification of about 0.1 psu was indicated by the "Salinity Snake" rigged up by Julian Schanze (SSS>37.5).  Hopefully tomorrow will have similar conditions for the VMP work.

We also managed to collect a bit of Sargassum weed, and photograph some of the inhabitants.  Lots of Trichodesmium around as well, looking like sawdust on the water.

A great day to be an oceanographer!

Ray Schmitt

Endeavor Update 13-03-26

From Endeavor Chief Scientist Ray Schmitt,

Just a quick update from Endeavor. Yesterday we successfully released and redeployed the WHOI mooring.  Perfect weather and Jeff was great as always. Today we launched 5 gliders; the two micro gliders were put in near Brian Ward's ASIP from the Sarmiento. We also recovered two Wavegliders.

Tonight we are steaming south to recover a drifting Seaglider, the mixed layer float and the PICO North mooring. If all goes well with those recoveries on Tuesday, we should be back on-site Wednesday for PICO mooring servicing (Prawler replacement on PICO-East) and if possible, the redeploy of PICO-North.  And recovery of 2 more Seagliders and 1 waveglider.

And Jordi invited me for lunch on the Sarmiento Wed.  We will play up the international cooperation angle, and plan some further work.  They have been generating some nice Seasoar sections.

Weather has been good here so far, though there are hurricane-force winds forecast north of us.

Cheers,

Ray

Slicing the Ocean

The deck of the SARMIENTO seems empty compared to other cruises, where usually anchors, sensors and other bulky equipment is piled up.

On the deck there are only two instruments strapped to the wooden floor. They look like well-fed yellow fish with a propeller at their tail.

These two instruments are called a SeaSoar and they are a key component to the survey we started 3 days ago. Once lowered into the water the instrument will be towed behind the ship at around 8 knots while it uses its wings to undulate between the surface and up to 400m taking continuous measurements of the water characteristics on its way.

SeaSoar deployment

These measurements include salinity, temperature, pressure, oxygen and fluorescence. The towed instrument provides much more profiles then a regular CTD sensor could achieve in the same time, since the traditional measurements require the ship to stop in order to lower the sensor.

Combining these measurements with the ships underway system, which collects temperature, salinity and fluorescence at the sea surface and maps ocean currents up to a depth of 600 meters, we collect a highly resolved data set of the upper water column.

The detailed pictures that we got after only a few days are truly fascinating. There is a sharply separated fresh feature in the upper 100 meters in the South and little pockets of subsurface salinity maxima detectable(see picture to the right).

Salinity from SeaSoar and Underway systems

In a few days the SARMIENTO will conduct another radiator-shaped survey further to the south to investigate meso-cale eddies that swirl in fresh and warm water from the south of the Sea Surface Salinity maximum and by that contribute to balance the loss of freshwater due to the excess evaporation in the subtropics.

Watching the sunset. while the SeaSoar is at work

Meanwhile the R/V ENDEAVOR has arrived in the SPURS area and will start working on servicing the moorings and autonomous platforms around it. On Wednesday the two ships are very close to each other near the central WHOI buoy and some folks might pay us a visit on the SARMIENTO, to discuss the plan for the next weeks and maybe have a ham sandwich or two...