data

Honey Badger is in its 61st mission day.  All is going pretty well.  The only issues that have come up are apparently linked to the software/computer interface with the systems.  When we average the data from Turner C3 that we can program on the fly, something in the glider's system is dividing by 2 (approximately).  We had this system (ID 32 on the data tab) running on single point measurements every 10 minutes for most of the mission.  However, we started taking 10 points at 1 Hz every 10 minutes and averaging them a few days ago to compare to the C3 (ID 3).  It is hardwired at this rate.  The reason for this is that starting around 10 June 2015, we started seeing extensive spiking in the C3-3.  We expected this and were interpreting the signal as phytoplankton aggregations or some other large organism with a chl signal (colonial radiolarians, for example).  The other C3 (32) was set on single point measurements and was giving us a different level of spiking. So, we decided to put them on the same frequency to see if they reported the same. This would eliminate fouling as a problem.
 

Turner C3-3 from the Honey Badger

Since starting this, they are looking the same. However, we have not found a low spiking area yet to confirm that the signal reduces simultaneously.  The data is in ERDDAP, so anyone can go replot this if they want to see more details (click on the window in that data page, it will take you to the server page).

This is all very good news.  We are excited by the geographic extent of this spiking.  A report by Karl et al (PNAS) indicated that a massive pulse of phytoplankton (probably symbiotic diatom/cyanobacteria)  occurs predictably at this time of year, and they are probably aggregated.  If this is what we are seeing, then this must be much larger than just of HOT (Hawai'i Ocean Time series station north of Oahu).  The thumbs of the camera pictures (looks downward from the bottom of the float) are not sufficient resolve anything unfortunately. The images are on the Honey Badger's computer awaiting it's (hopefully) triumphant return to Hawai'i.   The imaging system on the Sequioa LISST-Holo (holograms) should be capturing  detailed species data as well.  Again, we have to wait until Honey Badger returns  to extract it. Emily Anderson, the M.S. working on this, will have a LOT of images to look at. 

In the meantime, we are getting real-time physiological data on the phytoplankton from the Turner Phytoflash.  In between coffee breaks and dreamtime, it is recording data on two levels of fluorescence returned from different light flashes.  A manipulation of this data produces something we call Fv:Fm (technically variable fluorescence/maximum fluorescence).  The maximum value of this for this type of system is about 0.8 under perfect conditions (others max out at about 0.65 due to how this value is measured).  We are seeing consistent values at night of about 0.45. So, not in the best of shape, but there are number of factors likely reducing this number from its true value and we can try to correct for them.  However, the really interesting part is that we are seeing peaks at dawn and dusk that can be linked to nutrient limitation.  The dawn peaks seen in the figure below are what is predicted by a paper by M. Behernfeld et al (2006, Nature, doi:10.1038/nature05083).

These patterns indicated nitrogen limitation (red dots, 5 point running average).  If we find a bloom of the nitrogen-fixing symbioses we expect to, a reasonable expectation is that these patterns will shift to something else.  Iron limitation has a very distinctive signature in the Fm:Fv. It is not clear what other patterns look like (phosphorus or silicate), but we shall see what turns up.  The black dots are the Fm value (maximum fluorescence). It is akin to what the C3s are measuring and is the third chl fluorometer tracking spiking.  When plotted on the same scale, it shows much the same pattern as the C3s.  The oscillation seen in the data is the daily pattern.  High daytime solar radiation reduces the Fm and it rebounds at night.  This is the reason the Fm:Fv shows an oscillation as well. The daily fluorescence patterns are highly affected by daytime insolation.

This is all so cool.  I'm working at sea, and can go home tonight and make pizza.  Drink wine too, something a bit difficult to do on a UNOLS ship these days.  I attach an image of the most serious impediment to this type of work. 

Decisions, decisions

Honey Badger is currently 1070 km from home.  There have been a lot of clouds over the Honey Badger's area the past week, so it has been tough to figure out if the wispy blob of chlorophyll we set out to find was real or not.  However, the most recent one day imagery seems to show that there's nothing special there at the moment.  You can see way point 56 is in the middle of a nicely blue area, and all the interesting yellow-green (higher chl) is off to our west.  Honey Badger is  just at the eastern edge of the no data swath, heading east at 1.2 knots (practically a rooster tail).  Cara and I need to contemplate our options. 

1 day image 18 July 2015

Emily Anderson,  a new M.S. student in my lab, has arrived and is working on the data set.  We'll get her signed up to blog in the next week so she can keep us updated on what she's doing. 

The instruments are sending back good data, although the SMC computer and the phytoflash are not getting along very well.  The problem is likely in the software on the SMC running the phytflash.  It's a new configuration for the wave glider and our budget did not allow extensive testing of it.  Most of the time the phytoflash runs fine.   Periodically something in the system takes a time out from sampling (a coffee break, we call them) and returns in about an hour.  Sometimes it does not come back from the coffee break and goes into dreamtime.  I have to restart the system to get its attention and get the phytoflash running again. 

 Later this week, I"ll post some of the really interesting data we are seeing in the phytoflash.  It is showing the sorts of patterns reported by Mike Behrenfeld in one of his papers a few years ago, and it will allow us to make some interpretations about the types of nutrient limitations found in blooms.  Assuming we find one....

Lost and found

After a somewhat angst-filled morning, Danny, the wise project manager, noted that the tow cable is in plain view.  It is the line with the 4 marks, followed by the 5 bright spots. Those are the weights and floats on it.  I knew that.   So, the LISST-Holo is apparently still with us. 

On another note, the fish actually have names.  The 5 big ones are mahi-mahi and the two smaller blue ones (one has stripes) are pilot fish.  There is a bunch of fuzz on the left hand side of the image in front of the float. These could be small bait fish of some sort, or (more likely)  it could just be schmutz on the lens or camera port.   This is quite the collection.  Our own little Honey Badger ecosystem. 

Honey Badger made some friends...

This image was taken at 12:00 local time on July 1. The honey badger had just made an odd little loop de loop (centered at 28.15°N) which was probably related to some shear in the currents associated with the eddy we are heading into, but we took a look at the camera pics to make sure nothing was wrapped around the umbilical cord. What is worrying is that the holo tether isn't visible. Hopefully is it hidden behind the umbilical. We'll be looking at more pictures to try to confirm that it is still there.