Month: December 2024

Today we have been moving NE towards a station within the detached plume area, as indicated by the satellite image showing chlorophyll concentrations (left). From this, it can be seen that while the main part of the Amazon plume moves NW towards the Caribbean, another section splits off to move further E. For those who like to see images in “real” colours, the same phenomenon is also visible in the older (2012) satellite image from NASA (above). Chlorophyll is a good indicator of the plume, because the nutrients in the Amazon water allow microscopic, surface-dwelling ocean phytoplankton to feed and grow, and chlorophyll is the energy-producing pigment that gives plants their colour.

Of course the motion of the ship also takes its toll on some of the scientists on board, and sometimes we see a relatively empty canteen in the morning at breakfast time (although this is more often simply because some of the team have been up half the night working the equipment or taking water samples). At least it didn’t rain on us much today, so we can be thankful for this.

The weather has not been very kind to us today, and this has made the deployment and retrieval of of some of our sampling equipment trickier than usual. Strong, variable currents in the water column, coupled with wave action and surface wind, mean that the ship’s sophisticated dynamic positioning systems (and crew) have to work harder to maintain the ship in position over a piece of equipment that is suspended on a steel cable over 2km under the ship. It is interesting (at least to me) to hear the noise of the thruster working downstairs near the front of the vessel while the equipment is being let down or taken up.

So, our immediate goal today and tomorrow is, at least in part, to see if our sampling on this SW-NE transect evidences the presence of the east-moving plume, and our final sampling point on the line is calculated to be within it.

Don’t forget to check the Young Learner Page for additional posts.

Last night, shortly before 19:30, resident meteorologist Martin Stelzner showed me around the weather balloon container on the Meteor and let me see how things work.

The mechanism for release is cunningly simple – much simpler (and safer, I think) than a hand-launch operation. A large, fibreglass balloon holder contains at its base a tube that releases helium into the balloon. Once the balloon has reached a predetermined size, Martin secures a small radiosonde and gps/transmitter to it.

When ready, Martin simply opens a section in the container on the starboard side of the ship, and the balloon is automatically released. The balloon’s flight takes around 30 minutes, when it will rise to a height of around 25km. The radiosonde measures various atmospheric parameters such as pressure, wind speed and direction, and temperature, and transmits them by radio to a receiver onboard.

When the dataset is complete, Martin sends it directly to the German meteorological service Deutscher Wetterdienst and it becomes part of the complex German and global meteorological systems.

The release timing is strictly observed at all weather stations, and in our case the release was set to be at 19:30 and in darkness. It made filming and photographing a bit challenging, but with Martin’s help everything went well inside. Outside, I knew it would be a challenge – in 2018, I tried (and failed) to get footage of the balloon flight on the M147 cruise, in daylight: the balloon moves much more quickly than you expect! Now, I was not hopeful of even seeing the balloon in the dark. Watch the video to find out what happened.

It was great to see the device in action, and many thanks to Martin for his time and patience.

Don’t forget to check our Young Learner Page for additional posts.

We learned today that Andrea has just received an Exceptional Research Achievements award from Constructor University for her work in attracting research grants. This new award will come as no surprise to her colleagues, who are familiar with her unimpeachable professionalism and dedication.

On behalf, I’m sure, of everyone here on the RV Meteor, congratulations Andrea! Looks like the tea and cakes are on you!

Today I visited the Voltammetry Lab again to ask how things are going so far. After a couple of very busy water sampling days, the lab was quieter, but this was only because they were deep into their onboard analyses of titanium and nickel.

They told me that once the initial teething troubles were over, requiring them to calibrate the equipment and effect some repair and maintenance on a few items, they quickly settled into an efficient routine. They reflected that the water sampling organisation onboard was somewhat different from the previous Geotraces cruise (M147), but seemed to be working well, and there was a good deal of cooperation between the various teams. Indeed Cristian had been able to assist with some of the sampling routines, helping to maintain a smooth flow of sample water for filtration.

Alexandre was good enough to show me in some detail how the equipment works that they use in their DPAdCSV (I’ve been trying to memorise this for two weeks, but have failed totally – you will obviously know that it stands for Differential Pulse Adsorptive Cathodic Stripping Voltammetry). Rather than go into too much detail (cough), I’ll let you watch the video. It is of course very early for them to say much about the data they have collected, and much of the detailed analysis will only be done in the home lab. However, Alexandre reported that initial findings showed the amount of titanium found in samples was generally lower in the Pará transect than in 2018, which he attributes to the fact that there is now a much lower flow of freshwater into the estuary than at high water. He found little difference in the mangrove transect. On the other hand, Leandro had observed an increase in the concentration of nickel, which again may be attributable to the reduced flow of freshwater. In both cases, they are keen to get some samples from further into the river, if we are able to enter the northern Macapá channel.

Everyone agreed that there was the same level of friendly cooperation amongst all the teams and with the Captain and crew of the Meteor, and I’m happy to confirm this. Thanks for your time, guys. 🙂

Today marks day 15 of the cruise, arguably the half-way point. To mark the occasion, here are 15 assorted images, one from each day, that might not otherwise have made it onto the blog.

Today we moved further in towards the Amazon, leaving far behind us the shelf beyond which we had had depths of over 4,000m, and into shallower waters. First thing this morning, the Atlas Parasound P70 from Atlas Hydrographic GmbH was used by Rami Kalfouni to profile the sea bed, and results indicated a lovely muddy bottom at 750m, perfectly suited for station leader Mark Zindorf’s MUC deployment. Given the teething problems he and Sarima Vahrenkamp have experienced recently, and a seabed that has proved extremely reluctant to give up any samples, it looked like this could be a good station for the MUC.

It was not to be. This time it was not the depth, nor the sea bed, nor the equipment that caused the problem, but the current, which turned out to be too strong to make a safe deployment possible. The positioning systems on the Meteor are wonderful, but nothing can prevent a heavy piece of equipment from moving laterally as it descends on a steel cable to such depths in strong or unpredictable currents. In addition, the MUC could embed itself in the sediment, the effects of the current making it impossible for it to be retrieved cleanly. With it acting as a type of anchor, the cable could be placed under strain, or perhaps the equipment could be dragged along the bottom before coming free. There was therefore a clear risk to the multicorer, and at worst to the winch or even to the ship itself and those in it. In short, deployment of the MUC and the Bottom Water Sampler had to be cancelled.

Frustrating as it is, everyone knows that safety comes first, and we are now looking forward to the next station, with no unpleasant currents and a sea bed that is… not too hard and not too soft, but just right!