Mike Twardowski 3/9/16 Remarkable Technologies Used to Explore the Ocean


Well thank you Dennis for that wonderful introduction.
Thank you all for coming today. As Dennis mentioned, I’m talking about technologies
that we use to explore the ocean. This one slide, when I’m done with it is going to kind
of summarize my entire talk. This is a bunch of different oceanic phenomena that occur
in different time and space scales. So on the vertical axis here we have time. On the
horizontal axis we have horizontal spatial scales. We go from very small processes, molecular
processes. They go from particle to particle interactions, small scale turbulence in the
ocean to patch sizes, turbulent patch sizes in the ocean, surface waves, internal waves
– so when you have two different water masses that are separated by a significant density
gradient they can support internal waves. You have internal waves as well as surface
waves in the ocean. We have surface tides, plankton migration. If you guys were here
last week you heard Jim Sullivan talk about plankton migrations in the water column. Typically,
zooplankton will come up to the surface at night and feed and go back to the bottom during
the day and then opposite for some migrating phytoplankton. We go all the way out to seasonal mixed layer
depth, seasonal affects, cooling and heating, upwelling. Then we go way out to large scales.
We have El Nino southern oscillation which we’re currently in a very strong El Nino.
Then ultimately climate effects which are very, very long time horizon events. So the
challenge from a technology perspective is to try to resolve these different processes
with different platforms and different sensors. So one platform that we use is a tethered
mooring. So tethered moorings obviously have a very limited horizontal spatial scale but
they can sample as quickly as a minute. Some of these moorings have been out for decades.
There’s literally hundreds of moorings now around the coastal United States, mostly in
bayments. If you want to put a mooring on the coastal shelf it has to be a really expensive,
big mooring that requires a lot of attention, at least six months servicing. So it’s expensive.
Here in Indian River Lagoon, Dennis actually manages a system called LOBO Observatory which
is a whole sequence of a whole bunch of tethered moorings. So one very transformative piece of technology
is polar orbiting satellites. NASA has put a lot of different instrumentation on satellites
to sample the earth. One of the most important is ocean color which I’ll talk about quite
a bit today. But as you can see, the great thing about orbiting satellites is you can
resolve almost the entire planet in a day or two. So you get this incredible synoptic
view of what’s going on in the ocean. The first satellites with imagers went up
in the late 1970s and it really transformed how we do oceanography. Then the satellites
have been orbiting now for in some case decades, different satellites but they overlap so we
have a climate scale record of ocean color. So it really resolves a lot of very difficult
phenomena from a technology perspective. So it’s a very powerful technology. There’s also geostationary satellites. Geostationary
satellites, once they’re in orbit, they’re just looking at one place on the planet. You
can resolve, you can measure the ocean color and other properties of that one place very
rapidly or relatively rapidly. So in a matter of say every 15 minutes you could be sampling
one area of the ocean for ocean color. But you don’t get the larger spatial area coverage
that you do with the polar orbiting satellite. So the conventional way that we sample the
ocean is with a research vessel. As you can see, research vessels have a broad swath of
processes to spatial and temporal time scales that they can resolve. The problem with the
research vessel is it’s very expensive and we just have a few. So an ocean-going research
vessel will cost up to $50,000.00 to $60,000.00 a day. So what we’re trying to do as a community,
what we tried to do over the last couple of decades really is try to develop new technology
that can go out and autonomously sample the ocean with at least the same resolution, in
much case much higher resolution in terms of space and time at a far, far less cost. There’s also overflights. So you can have
cameras on airplanes. You can have a bunch of other different types of sensors to look
at things like temperature. You can even resolve structure vertically with laser imaging. As
you can see, you can sample a relatively large spatial scale in a pretty short period of
time with an overflight. So that’s the advantage of overflights. These are autonomous underwater vehicles.
I’ve combined here both propelled as well as gliding vehicles. What’s nice about these,
these are the kind of vehicles I was just mentioning that we’ve been trying to develop
that in many cases are just tens of thousands to put out – to buy and put out there in
the ocean. They can collect really amazing data sets. In most cases, far greater data
density than we collect with ships at far less cost. Profiling floats. So these are not tethered.
You throw them out in the ocean. They are like hot air balloons. They go up and down
in the ocean collecting data. These now – we have thousands of floats in the ocean throughout
the world and these are a really powerful sampling technology I’ll talk about a little
bit more later. In total, we pretty much have all those processes
resolved. So it becomes a challenge, too, because it leads to these concepts of an observatory
where you have all of these different types of technology all resolving different spatial
and temporal scales. There’s a lot of observatory initiatives that have been started. There’s
a National Science Foundation Ocean Observing Initiative which they have just completed
the infrastructure for. So now we have the infrastructure in the ocean. Starting in January they just started transmitting
data. I haven’t looked at the data. I don’t know the quality of the data yet. But it’s
a huge undertaking. It was a half a billion dollars’ appropriation from Congress. So we’re
very optimistic about the use of this data set for a very long time period to resolve
oceanic processes. There’s also with NOAA, Integrated Ocean Observing
System, and there are 11 of these throughout the country. The one for Florida here is called
SECOORA. So I’m going to start talking about all those different platforms that I mentioned
in that first slide. I’m first going to focus on remote sensing. So this is ocean color derived chlorophyll
concentration on the entire planet from the years of 1997 to 2006. This is from NASA Goddard
Space Flight Center. As you can see, amazing detail of all these larger scale features
in the ocean. Note here, in the southern Pacific this purple water. It’s extremely clear water.
It’s the most clear water on the planet. I’ll show some pictures of that water later on. You can also see equatorial upwelling here.
You can see a spring bloom in the North Pacific that then regresses to a summer bloom. A spiked
summer bloom in the poles. Over here you’ve got the monsoons. So it’s an incredible amount
of data that we didn’t have. So we knew things like upwelling occurred on western boundary
of continents. A lot of mesoscale from ship sampling, a lot
of mesoscale phenomenon but we had – we didn’t have the data that we needed to really
study and quantify those phenomena and then try to interpret that in terms of climate
change. So almost all current climate change models you hear about the climate change model
that comes out and it’s predicting so and so degrees are going to increase in the atmosphere
and the ocean over such a period of time. Almost all of that data is initialized with
satellite-derived measurements. Here you can see this upwelling off the coast
of Africa. This is actually because the world is spinning. The earth is spinning. As its
spinning it shifts water off shore so that water needs to be replaced. So deep water
is upwelled. The deep water is filled with nutrients. It comes into contact with light
and causes these phytoplankton blooms. Here you can see the Amazon River outflow. This
is the Oronoco outflow. So a tremendous amount of information. You have the imager on the satellite but there’s
also a whole sequence of technology, a whole suite of technology that’s used to calibrate
the sensor, to interpret the data, to validate the data, et cetera. So I’ll talk about that
a little later on. This is some very high-resolution data that was collected with an imager called
HICO which is Hyperspectral Imager for the Coastal Ocean. This is mounted on international
space station. This is where we’ve done some work in Western Lake Erie but you can see
the incredible detail of a very strong toxic bloom of cyanobacteria called microcystis. So when you think about the satellite imaging
problem you have solar energy coming through the atmosphere and the atmosphere scatters
light and it absorbs light and then you’re left with some incident light on the ocean
surface. That light is then modified by the waves. Then once it’s in water you have scattering
due to particles in the ocean and also by water molecules. Then there’s also a decrease
in intensity from absorption. Those are the two main processes. So it’s really pretty
simple. Those are the two processes that you have to quantify. Then at the satellite you’re looking at water.
The color of the water that you’re seeing is purely an effect of those scattering and
absorption properties of all the stuff in the water which are things like phytoplankton
which Jim showed some great images last week and Jan Ryan’s also several weeks ago showed
some great images. The challenge then is to connect this very fine scale sub-milliliter
type volume information of all the absorption and particulate scattering that’s happening
to the very big scale that the satellite sees. So this is a really interesting video. I don’t
have time to show the whole video but two kids in high school put Lego Man with a Canadian
flag on a weather balloon and sent it up. It’s really neat to see the video because
as it goes up you can see the atmospheric effects change, modify what we see looking
down more and more. So this is at 80,000 feet. At 80,000 feet you can see just pretty much
a blue glow. That’s due to scattering of the water molecules in the air as well as aerosols.
So when a satellite imager looks at the ocean about 90 percent of that signal is from the
atmosphere and we need to correct, we need to remove that to be able to look at ocean
color. I had a colleague at Dalhousie in Canada say that this is pretty much the extent of
the Canadian Space Program. [Laughter] There actually are several Canadian astronauts. So with ocean color you obviously have all
looked at the ocean and looked at water and you see that it changes color. That change
in color is a function of all the stuff that’s in the water. So this is off the California
Coast where it’s relatively oligotrophic because it is an upwelling area. There’s a lot of
phytoplankton in this water so it turns the water green because of the chlorophyll and
other pigments that the phytoplankton have. In the Mediterranean you get this deep, deep
blue. It’s relatively dark. So the reflectance, so the reflected light from the sun coming
out of the water is very little really compared to other places. It’s because it’s not only
water doing the absorbing and scattering that I mentioned but you also have some dissolved
material and some particulate material but at a much less concentration than you have
off somewhere like the California Coast. Then really, truly pure water actually has a very
bright violet look. It’s really breathtaking when you see it. This is the very clearest water in the world
in the South Pacific Ocean. This is right outside Easter Island. This reflectance – the
intensity of the light leaving the water is several factors higher than in these other
two places because water is dominating the reflectance and it’s a very effective scatter
of light in the backward direction. It’s a very bright, beautiful kind of violet lavender. So I mentioned there’s a lot of different
technologies that are required for ocean color remote sensing. You obviously have the imager.
This is the picture of the imager for SeaWIFS. SeaWIFS have eight different color bands.
Then a scientist trying to validate the radiance that SeaWIFS is measuring, so we deploy radiometers
in the ocean. So these are light meters and they look at
light coming in in every different direction. We try to quantify that and we can do things
like – I mentioned the very strong atmospheric correction. We can use these measurements
to try to validate those corrections. There’s also above water radiometers. This is a very important buoy called MOBY
which stands for Marine Optics Buoy. This is deployed just south of Hawaii in the middle
of the Pacific. There’s a counterpart for this buoy in the Mediterranean called BOUSSOLE.
This buoy is very important because this is the buoy that’s used to calibrate drift on
this satellite and other satellite imagers to this day. So it’s been in operation now
for decades. As you can see, it’s got long arms here. There’s
radiometers mounted on at the end of the arms. These radiometers, there’s a whole team that
do nothing but calibrate these radiometers and characterize these radiometers for deployment.
There’s two different MOBYs. This is MOBY 2. I took a picture. We did some work next
to the MOBY buoy a few years ago. This is buoy 2 that they put in this rack here. They go out to the site. They dump it in the
water. They take MOBY 1, put it back on the rack. They do this every six months and they
need a big University of Hawaii research vessel to do this. So it’s a big, expensive program
for calibrating the satellite. But this is the key way that we calibrate drift in the
satellite. We start to look back over decades, calibrating this drift at a very high level
is extremely important for climate change because in climate change we’re trying to
resolve very small changes, things like reflectance out of the ocean and the properties of the
ocean. So there’s a push now – we’re now a new
phase where we’re planning for the next imager to be launched and this imager is called PACE.
It’s scheduled to be launched in the 2022 timeframe. I’m on the PACE science team. Jim
Sullivan who’s also at Harbor Branch is on the PACE science team and we’re in the process
now of trying to define a lot of the specifications for that imager so it’s consistent with the
needs of the research team, research community. Part of that is new calibration methodologies
and protocols. So this is kind of a miniature version of a MOBY where you’ve got – it’s
a profiling float. So this autonomously profiles through the
water column and we have radiometers here on arms to measure hopefully very, very high
quality light data that we can use to calibrate the satellite in the future. This was just
presented at Ocean Sciences Conference last month and it’s a concept that’s currently
being developed by a company called WET Labs and Sea-Bird. So we have high hopes for that. This instrument package is kind of what our
group specializes in. So once you go from the satellite to light and ocean color at
the surface of the ocean then we need to interpret that reflectance in terms of all the stuff
that’s in the water. The first step in that is water has inherent optical characteristics
and that’s what this package measures here. There’s also a radiometer here. This dome
is a radiometer from Ken Voss’s lab at University of Miami. That resolves hemispherical light
coming down into the water. So this package here has a bunch of sensors
to resolve optical properties of water as well as things like size distribution of the
particles, chlorophyll concentration, all of those properties of the particles in the
dissolved material in the water that we’re trying to quantify with remote sensing. So
this really provides the link to that and allows us to develop algorithms to use that
data effectively. Then this is a towed vehicle. We call this the Dolphin. It has a lot of
the same instruments that are on this package but you can tow with it which is great because
as it tows you’re getting that depth resolution as well along tracks. Once you interpolate
you essentially get a ribbon of data and you can do all kinds of different tracks and I’ll
show some examples from that. But it’s turned out to be a very effective way of doing this
ocean color and remote sensing validation. Here’s a close up of one version of that package
where I’m highlighting the sensor here. So I mentioned that the two main processes in
the ocean that affect light are scattering and absorption and this is a device called
the MASCOT which is Multi-Angle Scattering Optical Tool for measuring scattering at multiple
angles. So there’s a source here, a laser source and this little cube here, this little
sample volume and all of these detectors are focused on that sample volume. So it measures
scattering from 10 degrees to 170 degrees. This is the only sensor in the world that
can make these measurements in water, in undisturbed water at very high fidelity. So there are
some instruments that measure on the bench top but once you collect the sample and bring
it to the bench top you’re disturbing a lot of the particles, sensitive aggregates and
such. So there’s two of these in the world and they’re both here at Harbor Branch in
our lab. So talk about some other platforms for sampling.
This is a conventional profiling platform off a conventional research vessel. So we
call this a CTD rosette and the C stands for Conductivity which we’d used to derive salinity,
Temperature, Depth and there’s also a variety of other instruments that we put not here.
There’s like turbidity sensors for looking at the approximation of particle concentration,
chlorophyll concentration, that kind of thing. Then these tubes here are actually bottles
that you can you use to sample the ocean. So as it goes through the water column we
can trip the bottles at different depths to collect water and then do analyses. Another type of vehicle is remotely operated
vehicle or ROV. This is very, very efficient, very effective at looking at relatively small
areas in great detail. It’s got thrusters so it can maintain position very, very well.
It’s got robotic arms that can be controlled remotely because it’s tethered. So people
at Harbor Branch have done a lot of great work with ROVs particularly around coral beds,
sampling corals and sponges and whatnot. So it’s a very powerful tool especially for sensors
that require a lot of power. So some imaging systems, LIDAR systems – so laser imaging
systems have been deployed off of these vehicles. Another type of platform is propelled autonomous
underwater vehicle. They come in all different sizes. One of the most popular is the Hydroid
REMUS family of vehicles. Hydroid is based in Massachusetts and really excellent engineers
who have done an excellent job in designing and fabricating and testing these vehicles
for the community. This is another company called Blue Fin. This
is a Blue Fin 21. It’s called a 21 because it is a 21-inch diameter vehicle. On this
vehicle you can see that there are some probes on the front that are used to measure very
small changes in current velocity in the water column. The on top we have that radiometer
that was on our profiling package that I showed earlier. There are some other optical light
sensors on top as well. This is a new AUV that’s very, very compact.
It’s only about a half a meter in length and it’s about five inches in diameter from Riptide.
But AUVs definitely have advantages in that they do have a relatively extended range.
You can go up to several kilometers. You can put a lot of different sensors on it. You
definitely have power limitations that you have to abide by. Typically, these are deployed on a daily basis.
So you put it in the water in the morning, will go through the day or go through the
night. You pick it up the next day. In some cases, they’ve been deployed for several days.
Because they are so power intensive, power hungry typically it’s just a day to a few
days’ deployment. So we actually have a proposal in right now
to work with these Riptide vehicles. Fraser Dalgleish has developed a concept for a laser
imaging system that’s small enough that could actually fit on one of these vehicles. Then
we can map coral beds and other benthic strata across the shelf off the coast of Florida
here. So we have our fingers crossed on that one. Another platform is called gliders. There’s
several different gliders that are commercial available out there. This is the Spray glider.
This is a Sea Glider from University of Washington Advanced Physics Lab. What these gliders do
in all cases is adjust their buoyancy by essentially fill a bag to change their volume. As they
change their volume they change their buoyancy and they’ll start sinking or they’ll start
rising. So in this case it’s at the surface. Shows
it transmitting data. So in this case it transmits data through its fin. Then it adjusts its
buoyancy so it’s negatively buoyant and it starts profiling through the water column.
Then it adjusts its buoyancy again to become positively buoyant and does an up-cast. It
keeps doing this. Because you’re only using power when you’re changing the buoyancy these
can be out in the ocean for a very long period of time. So several weeks. This one in particular can go down to 1,000
meters. This is another one that’s very popular in the scientific community, the Slocum Glider.
We’ve installed several different sensors on the Slocum Glider in the past. This is
some of the data collected off the New Jersey shelf showing salinity. Then here at the surface,
you can see effects of the Hudson River plume. These are optical measurements but they’re
optical measurements that are proxy for particle concentration. So you can see a lot of particles
associated with the plume but you can also see a lot of particles associated with resuspension
events near the bottom. Then this optical proxy here is a proxy for
organic versus inorganic mineral-type particles. So what this is showing is there’s a high
percentage of mineral particles near the bottom so we can not only characterize the concentration
of particles but also the composition of the particles with the optical sensors that we
have on these vehicles. You can see that if you were to go out on a ship and collect – this
is about a five-kilometer length here. So if you go out to collect a single vertical
profile through that and then if you’re trying to model the dynamics in the area of particle
movements, say, sediment bed fluxes and stuff like that you’d have to make an extrapolation
that might have significant error because there’s obviously a lot going on in that coastal
regime. So depth range. The Spray and the Sea Glider
have depth ranges of 1,000 meters. The Slocum has – it’s more for coastal continental
shelf work. So it has a depth range of 100 meters. This duration typically is a month
but there are exceptions. In particular, the Rutgers Glider Group sent a Slocum Glider
across the entire Atlantic and it took it I think 200 days and it traversed about 7,000
miles when it was all done but it made it. So there are exceptions. But for the most
case, for collecting high-quality data it’s typically a month. The payload is very compact. So as you can
see here, this is only a foot in length and about eight inches in diameter. The power,
there are definitely power constraints. So these sensors actually were developed for
the gliders I’m going to show here. So these are sensors that make measurements that are
the highest quality measurements that we make as far as optical properties of the water
that we can use to characterize particles and all those things I was talking about.
But as you can see, this is the payload section of a glider and you’re not going to fit those
in the payload section of a glider. So we had to develop these sensors that make
the same measurements almost at the same quality but at a much, much smaller form factor. It’s
also hydrodynamic. They also use just simple LED light-emitting diode light sources. So
it’s very, very low power consumption. We did this in collaboration with the Rutgers
Glider Team and Oscar Schofield. Another type of platform is profiling floats.
These are incredibly useful platforms and there’s tons of them all over the ocean right
now collecting very, very important data for a lot of different applications. Most prevalent
one is called ARGO, developed by Teledyne Webb. You can put, as you can see, a variety
of different sensors on them measuring a variety of different properties of the water. Another one that has come online to the community
in the last year or two is called Navis from Sea-Bird Electronics. Then this is what I
showed before that – a NAVIS that’s been adapted to hopefully be a calibration platform
for future satellites. It’s called a NAVIS-OC. The PROVOR is a French version of these profiling
floats. But again, what these typically do is they
change – they’re at the surface of the water. They change their ballasts so that they’re
negatively buoyant. They go down to a depth of approximately 2,000 meters. They’ll stay
there for one to two weeks and then do an upcast, transmit the data to a satellite and
then go back down to 2,000 meters and it just repeats that. Since you’re only using energy
when you need to change the buoyancy these can operate for a very long period of time.
These are out there for years, nominally five years but there are some floats that have
gone much, much longer than that. Here’s a good example of using float data
to validate remote sensing measurements. So this is chlorophyll concentration here. This
is a three-year time series. The vertical axis here is depth. This is all the data from
the float deployed in the Labrador Sea. You can see in the winter the mixed layer depth
dives way down and it had a big storm that came that year to make a very, very deep mixed
layer depth. You can see most of the chlorophyll’s in the surface. So what Boss et al did was
took the chlorophyll concentration at the surface and then compared it to the chlorophyll
concentration derived from the satellite. You can see there’s a very nice correlation. The limitation of a satellite even though
it’s incredibly useful is that you’re just looking at surface water. So you don’t get
all of this vertical resolution that you can get with floats and other types of platforms.
So that’s why it’s very, very important to try an integrate all of these different platforms
and the data and the space and time scales that they measure over. But it’s a very challenging
thing to do and not many people, to be honest, have really done it well to answer specific
science questions. So this is the ARGO float distribution. This
is a little old. So it’s 3,300 floats. Currently there are almost 4,000 floats throughout the
world and there’s more than 50 countries that are participating in the program. This is
an amazing data set that when we talk about questions like, “Is the ocean warming over
time,” this is the data set that’s always cited. It’s definitively yes. First one was
deployed in 2000 so they’ve just been out for about 16 years. So it hasn’t been that
long but even over that relatively short time scale we still know definitively because of
the amazing distribution and the quality of data that’s collected that the ocean is warming. So the next type of platform I’m going to
talk about is a towed vehicle. I mentioned before that there was a counterpart to MOBY
called BOUSSOLE. This is the in the Mediterranean and we did a lot of measurements both around
MOBY and BOUSSOLE with this vehicle. But you can see that you can do spirals to kind of
resolve in almost three-dimensions what’s going on after you do interpolation. What
this plot is down here is taking the spiral tow and unraveling the whole thing. You can
see that there’s a relatively strong chlorophyll layer here at about at 30 meters. So that’s
what this color is, this chlorophyll concentration. Then we can derive from all this data, that
block of data what the surface reflectance that a satellite would see in about – this
is about the size of a single pixel on an image that a satellite would see. This is
another data set from Long Island Sound where we used this towed vehicle. We made a north
to south transect here. So we started – this is the outflow of the Connecticut River on
Long Island Sound. So we started the outflow of the river and were in the plume and then
we went due south from there. In the process of that tow with this vehicle made approximately
– it’s several hundred profiles. This is salinity here as a function of latitude. You
can see in the northern part here’s a current of high salinity going towards the west and
then this is relatively low salinity coming to the east. This higher salinity water is
entrained open ocean water that comes through the mouth of the Sound here. Then these are optical measurements. These
are raw optical measurements that we made. But what I want to point your attention to
are these other properties that we’re able to derive from the optical measurements. So
PSD stands for Particle Size Distribution. The slope of that size distribution is reflective
of the relative amount of small to large particles. So when it’s high – so when this is red
you’ve got a lot of – a lot more small particles. When it’s blue you’ve got a lot more large
particles. The TSM here is Total Suspended Matter. This
is if you went out in the ocean, you collected a sample, you filtered out all the particles
onto a filter and weighed it. So you had a mass concentration. That’s what this shows.
Percent POM is Percent Particulate Organic Material. So there’s two types of particulate
material. There’s organic, carbon-based. Typically, it has a relatively low density
and then you have mineral particles that have typically a very high density and they have
very different optical characteristics. So we’re able to distinguish them. Then we have
chlorophyll concentration here. If you look at chlorophyll, it’s clear in the southern
end here that we have a bloom occurring. There’s high chlorophyll concentrations. Associated with that are relatively large
particles. These were diatoms, relatively large diatoms that are phytoplankton that
were in the water column that were blooming at the time. Then this water mass here that’s
entrained open ocean water caused the resuspension event here. So you can see a high concentration
of particulate material, TSM, Total Suspended Material. It had a very low percentage of
organic in its composition. So it was primarily inorganic sediments that were resuspended. Then with the plume of the Connecticut River
here, you can see it’s relatively small particles. There’s no chlorophyll, essentially very little
chlorophyll and it’s relatively high in organic material. This is just showing the kind of
data and the kind of resolution that you can get with one of these platforms and the sensors
that are on it. Again, if you were conventionally going out with a research vessel and just
taking initial profiles it would be very difficult to get a synoptic picture so that you could
then make sense of that in models and interpretations. Another platform is drifters. Drifters come
in all different sizes. This is a very big drifter, approximately a meter. It’s greater
than a meter in diameter that was deployed in the Southern Ocean Gas Exchange Experiment
that we participated in a few years ago. This is a drifter that we developed in our lab.
It’s a very compact drifter and it’s because it was designed to sample surf zone. So when
you’re sampling the surf zone you want as compact a drifter as possible so it stays
with the current because that’s what you’re trying to resolve, current velocities through
the surf zone. So the water line was right at the top here
and this little cup here which is the Iridium satellite communications. That’s the only
part that was sticking out. So when you have breaking waves and you have wind it’s not
going to be effected too much by that. But we’ve collected a lot of data for the Navy
of optical properties in the surf zone because they were interested in trying to look through
the surf zone trying to image things that might be on the bottom and developing technologies
to enable that. It’s really amazing the currents in the surf zones. We could put these in some
surf zones and after ten minutes they’d be half a kilometer away, like right here, right
where the waves are breaking. So the currents there are really impressive. This is another platform that I wanted to
show you just because it was really a great experience working on this platform. It’s
called the CRAB, Coastal Research Amphibious Buggy at the Duck Facility for the U.S. Army
Corps of Engineers where a lot of great research has been done over the years. They have a
fantastic facility there. We mounted our equipment on this CRAB and we were able to roll it out
into the surf zone. It has these big wheels. Then we can a profile through the middle.
So we’re able to collect a lot of data, a lot time series data. We were specifically looking at bubble concentrations
over time and from those bubble concentrations we can derive things like visibility and most
importantly for the surf zone statistics and visibility. Because in any one instant, it’s
almost impossible to predict how far you’re going to see but you can say over time you’ve
got an 80 percent chance that you will be able to see the bottom or whatever that percentage
is. So we made those measurements for them. Then another platform finally is divers. Divers
can be extraordinarily useful. Obviously, they have limitations but there’s some things
only divers can do. This is a great picture of a colleague, Emanuel Boss. He’s got tons
of equipment mounted to his back and the thing that he’s holding is a tube that’s sucking
in water to go through all of these different sensors. So he went in and around coral reefs
and a lot of different area making very fine-scale measurements that would be difficult to do
otherwise. This here’s a colleague, Brandon Russell,
and he’s got a spectrometer looking at the bottom. So when we’re looking at light fields,
the reflectance off the bottom has a big effect usually in shallow waters on that light field.
So he’s quantifying that. But it’s a handheld instrument that you have to have a diver to
do. This is a wave glider platform here. We have one here I think at Harbor Branch. I
think we’re getting another one soon. But essentially there’s a bungee that connects
this bottom structure and the surface structure which is like a surfboard and as waves come
through the surfboard it modulates that and propels it forward. So with all of these different platforms and
all of these different sensing technologies they all have to be designed to withstand
all the elements of the marine environment which is really very challenging. One of the
most challenging aspects that we’re still struggling a lot with is biofouling. Here
we’ve done a lot of experiments over the years looking at biofouling. With different films.
So all of these different optical windows have different films on them. Obviously, light’s not getting through a few
of these too well. But you know, our sensors are very finely calibrated and we know exactly
how much light is coming out that window. When they get fouled it completely changes
the calibration on the sensors and interpretation and everything. So it’s a serious problem.
Just mechanically it can be a really serious problem too when you have mussels and all
this stuff growing on structures. Pressure. Obviously, deep in the ocean the
pressures are enormous and you need to build sensors that can withstand that. Sea state.
This is a picture from the Southern Ocean during that Southern Ocean Gas Ex Experiment
that I had mentioned. Huge waves. It was on this cruise actually that this CTD rosette
got damaged. It was banged on the side of the ship and the welded frame actually shattered.
It broke a lot of these bottles here. I could say I’ve been on research cruises in the North
Atlantic in the winter where for two weeks we just had 20, 30-foot waves and we got basically
nothing done. So it’s another reason why going out on an expensive research vessel is not
always the best way to do science and a lot of these robotic drones can be very, very
effective even in those kind of environments. Strong temperature gradients. Electrical systems
are very sensitive. Temperature gradients, electro-chemistry in the water. Pretty much
everything corrodes in water unless it’s titanium which a lot of instruments are made out of
titanium for that reason. Very limited communications. Then animals can also be a problem. We’ve
had seals go in and rip out cords in our packages before. Here’s – we were in the South Pacific.
We had a shark that was attacking our sensors. So the chef got a – this is a fish head
that he’s putting it in the water to try to distract the shark away from our sensors so
we can bring it in real quick. So I think I have a little time to talk about
imaging. So this is some imaging work that we did off the Florida Keys in association
with the Naval Undersea Warfare Center. So the Navy has this camera and this camera is
mounted on underwater vessels and I can’t tell you any more than that. But you can probably
imagine what it is. They’re trying to image stuff on the hulls of ships. What they found
out in doing this over the last few years is that there are a lot of times where it
was turbid and they couldn’t really see much. So we developed this very compact optical
sensing device that can sample the environmental optical properties and then predict how far
the camera will be able to see for a specific target of a specific contrast, et cetera.
So this experiment here was testing that algorithm and that sensor, the integrated sensor package.
You can see contrast targets on the bottom of the hull here. That went really well. This
is currently both the camera or I should say a next generation camera as well as this optical
package are being installed on these underwater vessels now. This is some great laser imaging work done
here at Harbor Branch by Fraser Dalgleish’s research lab. The advantage in using a laser
imaging system is that you can get finer detail than you can with a passive system, just a
camera or a camera with an active source and you can also see over much, much farther ranges
than you can with passive camera technologies. Then finally, imaging – obviously, we’re
trying to detect things with imaging equipment but there’s also the inverse. The Navy’s very
interested in this in trying to hide stuff in water which brings up camouflage. With
camouflage you need to know – you need to optimize your camouflage optically but then
you also need to know what the adversarial imaging system, it’s capabilities are as well
and any performance algorithm. To give you an idea, we’ve been involved in a project
where we’re trying to look at how animals do this in the ocean. The whole idea is to try to mimic what they
do in terms of the technology that we develop. This is an octopus camouflaging itself. So
when it’s fully camouflaged it’s truly camouflaged. It’s really remarkable what they can do. So
it’s matching all the different colors. It’s matching the pattern of the colors as well
as brightness which is really reflectivity. So it’s reflecting all the ambient light that’s
around it. These are all optical characteristics that we studied in detail in our study. This is one experiment from that study that
I’ll just – I’ll very briefly talk about where we developed an association with Alex
Gilerson at CCNY, City College of New York. He developed this system here to look at basically
light parameters in all dimensions. So we knew exactly what the light field was around
these fish. This is specifically – this experiment was looking at fish. Then we also
had a camera that was sensitive to polarization. If any of you are photographers sometimes
you may use a polarization filter. But light travels in waves and this little cartoon shows
that light coming from the sun is unpolarized. So all these different waves are on all different
orientation. It’s completely mixed. But once that light bounces off a surface it imparts
a specific polarization to that reflected beam. Fish camouflage themselves. Their scales are
like mirrors. So the light hitting the scales bounces off. In doing that they can very closely
match the background color. They can also match the background intensity. But if they
acted just like a mirror they would actually impart polarization specificity to that scattered
light, that reflected light, that a predator would be able to see. So that’s what we wanted
to test in this experiment. What we found is that they have structures in their scales
that actually scramble the polarization so it does actually look like the background.
So that was the main finding in this study. So a final thought. This is really a terrific
platform that I’ve been very fortunate to work off a few years ago called FLIP. It was
built by the Navy in 1962. It’s a barge so it doesn’t have any propeller. It doesn’t
have any motor. What they start doing – it’s towed out to the location that you want to
be out in the middle of the ocean. They start pumping water into the end of the barge and
it starts to flip. It essentially starts to sink. When you watch this happening you’re
thinking it’s going to ‘wheek’, the whole thing’s gone. But it’s not the case. What
happens is you end up with this platform, this laboratory at the surface of the water. So it’s 355 feet in length and 300 feet of
that length is underwater, this ballast. What that does it creates – it’s called a spar
buoy design and it creates a tremendous amount of stability in making measurements so that
you can have wave field going by and the platform essentially doesn’t move. It’s going to drift
with currents but it doesn’t move relative to these waves. This was built in 1962 so
it’s been used for over 50 years. It’s still used on a regular basis. Literally, constantly
it’s being used. Some of the very, very best wave research
that has ever been done and also surface water circulation research that have ever been done
has been done on this platform. It’s a really remarkable platform. You can see there’s three
booms here. This is one boom that’s out and that’s a guy standing on it and a guy – he’s
playing with a sensor on that but you can see – kind of get an idea of how big it
is. Incredibly valuable platform. So recently the French government said, “We
need a FLIP.” So they started going into design work and all the risk assessments and all
that. Eventually they said it was impossible. So obviously it’s not impossible because it’s
been done. But the point is it was impossible with all the constraints that we have today
in developing new platforms, new technologies. So obviously, there’s risk assessment in terms
of safety hazards. When this thing is flipping – they have toilets and sinks and kitchens
and everything needs to be reoriented. So the toilets actually have two holes. So you
have to unbutton – the kitchen, the refrigerator, the oven, the counter space, everything is
on an axle so as it rotates it just rotates on the axle. It’s really incredible. So they said it couldn’t be done but it’s
because of the regulations. It’s because of the constraints in terms of safety, et cetera.
There’s also a story I’d like to tell about last summer I was moderating a discussion
of technology with undergraduates at University of Connecticut. The discussions kept boiling
down to, “Well that would be too costly and that might be dangerous and that could be
a really risky thing to do.” These guys didn’t think that way. So they first looked at the
science needs, the science problems, developed a concept, developed the design and then figured
out how to work the constraints around that. I think this is a final point. I really think
we need to do more of that today. I’d also like to point out that this vessel
as well as almost every piece of technology that I showed you today was originally funded
by our Navy which is very impressive. It’s not funded by corporations. It’s not funded
by other agencies. The National Science Foundation the big, premier scientific agency in the
United States, did not fund any of this technology development except for the SeaWIFS imager
which was funded by NASA. So I’d like to close by acknowledging the
research group that works with us. This is Schuyler Nardelli. Schuyler is attending graduate
school in the fall but she’s already got some great offers from some of the leading oceanographic
programs in the country. This is Aditya who’s a post-doc who specializes in bio-physics.
This is Nicole and Nicole pretty much does everything in our group. She’s the engineer
that puts together these packages. She processes all the data. She goes on the cruises, collects
the data. Here, she’s doing everything she can to collect good data. She’s holding a
GPS the only place it’s going to get a fix. This is Malcolm who’s a post-doc in our group
as well. His specialty is bio-optics. This is a coffee shop. Island Hoppin’ Brew here.
It’s a coffee shop. This is Alberto Tunitsa who’s doing kind of a remote post-doc with
us in New York City and he’s primarily working on ocean color. I can show him without a shirt
because he’s not here [laughter]. Then finally, I’d like to acknowledge all
the collaborators I’ve worked with over the years. These are just some of them. But they’re
all great scientists, great people to work with and I feel very fortunate in working
with them all. So thank you very much.



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