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Ship-Aircraft Bio-Optical Research (SABOR): Visitors at Sea: Local Wildlife Observe Science in Action

July 22nd, 2014 by Kathryn Hansen


Text by Robert Foster

City College of New York – CUNY

Here we are ending the 4th full day aboard the R/V Endeavor, and I can hardly believe it! Time really does fly when you’re having fun! Amid the rush of running cables, installing sensors, learning new and exciting science and making new friends, I couldn’t be happier. I am a 3rd year Ph.D student in the Electrical Engineering department of The City College of New York, and through extremely fortunate circumstance I found myself working in the Optical Remote Sensing Lab of NOAA-CREST.

Life aboard the R/V Endeavor is both exhilarating and exhausting! During our safety briefing I jumped into an immersion “Gumby” suit for the first time, giving my colleagues a good laugh as I tried to close the face flap with my lobster claw gloves.

I’m trying on the immersion suit for the first time and posing “mannequin-style” for the safety briefing Friday morning. Photo courtesy of Ivona Cetinic, University of Maine

I’m trying on the immersion suit for the first time and posing “mannequin-style” for the safety briefing Friday morning. Photo courtesy of Ivona Cetinic, University of Maine

Although we’re currently 18 miles off the shore of New Hampshire, we’ve already had several visitors!

On Saturday morning we spotted a pod of whales in the distance. They were too far away to photograph, but we could clearly make out their sprays and tailfins when they dove.

And the dolphins! This was the best part. Just a couple hours after leaving port on Friday the entire science team was on deck learning how to deploy the CTD when a pod of dolphins started leaping out of the water not 20 feet from the ship! It was almost as if they wanted to see us off on our journey! We managed to snap some really fantastic photos.

Dolphins jumping out of the water to see us off! Photo courtesy of Ivona Cetinic, University of Maine

Dolphins jumping out of the water to see us off! Photo courtesy of Ivona Cetinic, University of Maine

Slightly more numerous than dolphins are the tiny phytoplankton which provide us with so much of the oxygen we breathe. Inside Endeavor’s main lab is an amazing instrument that can actually take pictures of these microscopic creatures and count them! Since one of SABOR’s primary science goals is to quantify how much carbon is being converted into oxygen by marine life, it is vital that we know exactly what species are present and in what concentrations.

Of course it’s impossible for the R/V Endeavor to be everywhere at once, so we must rely heavily on satellite observations. Current sensors such as MODIS (Moderate-Resolution Imaging Spectroradiometer) aboard the Aqua satellite and VIIRS (Visible-Infrared Imaging Radiometer Suite) aboard the Suomi NPP platform are designed to observe the ocean and atmosphere. Although they do it quite well in a general sense, there is still too much uncertainty to make absolute assessments of climate change and carbon cycling.

When we as humans look at an object, what is it that we’re actually seeing? (No, it’s not a philosophical question!) We see color and brightness. Seems sufficient, doesn’t it? But it turns out that there is actually another hidden property of light that we can’t see with our eyes, and it’s called polarization.

So if we can’t see the polarization of light, why do we care about it? Why is it a major focus of SABOR? The answer is because it’s becoming more and more difficult to increase the accuracy of satellite measurements using color and brightness alone. By incorporating polarization into our measurements, we are opening up a whole new dimension of information that was previously inaccessible. Our laboratory at the City College of New York is studying the way light becomes polarized in various conditions both above and below the surface of the ocean.

The first of the two instruments that we designed at City College is called HyperSAS-Pol. It is designed to automatically look at a fixed angle relative to the sun, regardless of the direction the ship is facing. HyperSAS-Pol measures both the polarization of sky light, and also light coming from the ocean.

I’m setting up HyperSAS-Pol on the bow tower of the R/V Endeavor. Photo courtesy of Alex Gilerson, City College of New York

I’m setting up HyperSAS-Pol on the bow tower of the R/V Endeavor. Photo courtesy of Alex Gilerson, City College of New York

Our second instrument floats on the surface of the ocean and measures the polarization of light underwater. We can rotate the instrument by using propellers that are attached to its arms. The sensors themselves are attached to a stepper motor which can look up or down in the water. With these two motions we can measure polarized light in any direction. By the way, this instrument doesn’t have an awesome code name like HyperSAS. We just call it the polarimeter… pretty boring name, I know. Maybe you can think of a better one? Post a comment!

Our floating polarimeter. Photo courtesy of Alex Gilerson, City College of New York

Our floating polarimeter. Photo courtesy of Alex Gilerson, City College of New York

While we are taking measurements on the R/V Endeavor, a plane will be crossing our path several times with a sensor capable of measuring polarization, as well as a LIDAR. During their test flight on Sunday afternoon we were able to watch the plane corkscrew down from the clouds to circle the ship! Too cool. They even took a picture of us!

The NASA Langley plane circling the R/V Endeavor on Sunday afternoon. Photo courtesy of Wayne Slade, Sequoia Scientific

The NASA Langley plane circling the R/V Endeavor on Sunday afternoon. Photo courtesy of Wayne Slade, Sequoia Scientific

The R/V Endeavor as seen from the sky! Photo courtesy of David Harper, NASA Langley Research Center

The R/V Endeavor as seen from the sky! Photo courtesy of David Harper, NASA Langley Research Center

Between the combined efforts of everyone onboard the R/V Endeavor and in the sky, we will be able to trace the complete path of polarized light coming from the sun, down through the atmosphere, into the water, interacting with all the little sea critters and finally emerging back into space to be captured by one of NASA’s Earth Observing satellites. If successful, our work here will be instrumental in the design of next generation satellites, such as the PACE mission.

We have one final visitor who is here in spirit, and his scientific value is without doubt. He makes sure that no light gets reflected off the white buoys and contaminates our underwater sensors. He is a childhood friend of mine, but I’m sure that you’ve met him before too!

Our very special colleague. Photo courtesy of Chris Armanetti, R/V Endeavor

Our very special colleague. Photo courtesy of Chris Armanetti, R/V Endeavor

 

 

Ship-Aircraft Bio-Optical Research (SABOR): Beakers and Blankets: Readying for SABOR’s Ocean Voyage

July 15th, 2014 by Kathryn Hansen

Starting July 2014, scientists with NASA’s Ship-Aircraft Bio-Optical Research (SABOR) experiment will make observations from ship and aircraft off the U.S. Atlantic Coast aimed at advancing the technology needed to measure microscopic plankton in the ocean from space. For the next three weeks, follow SABOR researchers as they work toward finding out how and why plankton are changing around the planet, and where the carbon associated with plankton goes. Plankton play an important part of the climate system and deliver oxygen to the atmosphere, absorb carbon dioxide, and form the base of the marine food chain.

The following post is by Nerissa Fisher
Oregon State University

Clockwise from top left: A zooplankton species with a thalssiosira chain in the background; Paralia spp.; a colony of what may be dinoflagellates, and; a ciliate in a protective house -- it is most likely that the ciliate ate the phytoplankton that made this outter shell and it now using the shell for protection agianst zooplankton.

Clockwise from top left: a zooplankton species with a thalssiosira chain in the background; Paralia spp.; a colony of what may be dinoflagellates, and; a ciliate in a protective house — it is most likely that the ciliate ate the phytoplankton that made this outter shell and it now using the shell for protection against zooplankton.

Only three days until the SABOR cruise and I couldn’t be more excited! I have just finished my first year of graduate school in the Microbiology department at Oregon State University where I am pursuing my Master’s degree. I have been on several cruises before, one in the Gulf of Mexico and a couple in Bermuda, but this will be the longest cruise I have ever been on. This is also the first cruise where I have not worked at the research station where the cruise departs, so the entire process of preparing and packing for this cruise that is on the opposite coast has been a much different experience. In past cruises I was not so involved with preparation and my biggest concerns were making sure I had the right clothes and shoes for ship work or the packing list had already been determined and I made sure everything on the list got on the ship. Our research team has had several meetings to discuss the experiments and materials we need to pack. It seems like no matter how far in advance we started packing for this cruise we are still shipping boxes to the east coast. Silly things, like making sure we have beakers to mix solutions in, and all the little knick-knacks that are required for experiments have to be thought of in advance, because once you have left the dock there is no supply closet to run to if materials are missing.

Our research group is measuring how efficiently light energy is converted into phytoplankton biomass. To do this, we are making a number of different measurements simultaneously. Some of these measurements use a state-of-the-art flow cytometer, some use radioisotopes, and some are much simpler and involve filtering seawater and measuring chlorophyll, the pigment that phytoplankton use to absorb light for photosynthesis.

My life in the days leading up to this cruise has been most exhilarating. This past Friday and Saturday were completely booked doing phytoplankton bio-fractionation experiments for my thesis research. I wanted to finish those experiments so that I have data to analyze while on the cruise. Then Sunday, I absolutely HAD to watch the world cup final, which was a fantastic game!! As often as I could pull my attention away from the match, I was also sewing garments that will be used to shade seawater incubation bottles that will allow me to measure primary production at various light intensities.

An SEM picture of Thalassiosira pseudonana provided by Alfred Wegener Institute.

An SEM picture of Thalassiosira pseudonana provided by Alfred Wegener Institute.

Ok, so maybe this doesn’t sound all that exhilarating, but I love phytoplankton ecophysiology, and I could not be more excited to have this opportunity to be at sea for three weeks collecting data that could provide much clearer insights into marine carbon cycling and meet other scientists in the same field. I will have a unique opportunity to apply the measurements I have collected for my research in the laboratory to understand how photosynthetic energy is allocated to different cell compartments, to field samples. This work could potentially be the second chapter of my thesis and broaden my current findings for a single diatom species (Thalassiosira pseudonana, see image above) to natural populations. Without these amazing primary producers of the sea, life on Earth would not exist as we know it and I can’t think of more important work than trying to better understand their physiology, especially in a world that is changing more rapidly than ever before. I am ready to be surrounded by great people, fun, yet exhausting, experiments, and nothing but blue.

South Pacific Bio-optics Cruise 2014: Societal Benefits of Ocean Color

May 10th, 2014 by Aimee Neeley

My apologies for the gap between blog posts.  My day job has been pretty busy.  And even though the NASA folks have already arrived safely to Tahiti as of May 5,  2014, I thought it was fitting to have one last blog post. We have talked a lot about ocean biogeochemical sampling, ocean chemistry, and ocean color radiometry.  It is also important to touch on the societal benefits that ocean color radiometry can provide.

In 2007, the  International Ocean-Colour Coordinating Group or IOCCG published a report and an additional brochure entitled: “Why Ocean Colour?  The Societal Benefits of Ocean-Colour Technology” and “Why Ocean Colour.”  I will not go into all of the information detailed in each document here (though feel free to follow the links below at your leisure.)

IOCCG reports

IOCCG reports

A number of critical uses for ocean color are of particular importance in today’s society. For instance, detection of high algal biomass can indicate the location of potential fishing zone.  Fish that eat algae or fish that eat fish that eat algae (did you get all of that?) will be en masse in these blooms.  Inter-annual variation in timing and extent of phytoplankton blooms can also affect the survival of larval fish.  Satellite imagery can be used to monitor this variation.  Moreover, satellite derived sea surface temperature (SST) and wave height information can help aquaculture developers plan where to establish new fish farms.  Satellite imagery can be used to detect and monitor blooms of harmful algae, algae (phytoplankton) that ether produce toxins or can clog the gills of fish and invertebrates because of high biomass.

Harmful Algae Bloom in Lake Erie  http://oceanservice.noaa.gov/hazards/hab/

Harmful Algae Bloom in Lake Erie
http://oceanservice.noaa.gov/hazards/hab/

Satellite ocean color imagery is also very important for monitoring delicate ecosystems, particularly in global coastal environments.  For example, the European Space Agency (ESA) has developed a program called CoastWatch that helps scientists harness the power of satellite imagery for monitoring water quality in shipping channels and coastal environments.  The Medium Resolution Imaging Spectrometer (MERIS) on the Envisat platform (similar to NASA’s MODIS instruments) can be used to monitor sediment deposition onto coral reefs, which can smother the corals.  The imagery can also be used to monitor water quality in shipping channels after dredging.  Dredging can increase suspended sediments and negatively affect water quality.

MERIS image: sediments flowing onto reef http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

MERIS image: sediments flowing onto the Great Barrier reef in Australia
http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

Let’s consider a recent ecological disaster: the Deepwater Horizon oil spill. The Deepwater Horizon oil spill has been called the ‘worst oil spill in U.S. history’. The oil spill resulted from an oil platform explosion that occurred on April 20, 2010, and leaked an estimated 4.9 million barrels of oil by the time it was capped on July 15, 2010.  This type of disaster can have long-term impacts on coastal wildlife and fisheries.  Immediately following the spill, fishing areas around the Gulf Coast were closed to prevent human exposure to dangerous chemicals, polycyclic aromatic hydrocarbons, found in the oil.  These chemicals are known to cause cancer. The fisheries were deemed safe and reopened on April 19, 2011.

Oil in the marshes of the Mississippi Delta  http://ocean.si.edu/gulf-oil-spill

Oil in the marshes of the Mississippi Delta
http://ocean.si.edu/gulf-oil-spill

Dolphins swimming through the oil patches from the Deepwater Horizon spill http://ocean.si.edu/gulf-oil-spill

Dolphins swimming through the oil patches from the Deepwater Horizon spill
http://ocean.si.edu/gulf-oil-spill

Satellite ocean color imagery can be used to locate and monitor oil spills of this magnitude.  Although this type of imagery is complex, the technology is a great asset.  The video below, developed by video producers here at NASA Goddard, shows a timeline of NASA MODIS satellite images. Such imagery allowed scientists to follow the track of the oil slicks.  These images can help us prepare for the impact of these disasters when we know where it is headed next.  You can find satellite images of the oil spill here.

 

Satellite image of oil slick in the Gulf of Mexico following the sinking of the Deepwater Horizon platform  http://www.nasa.gov/multimedia/imagegallery/image_feature_1649.html

Satellite image of oil slick in the Gulf of Mexico following the sinking of the Deepwater Horizon platform
http://www.nasa.gov/multimedia/imagegallery/image_feature_1649.html

We have truly enjoyed sharing our experiences with all the blog readers.  I hope we can do this again very soon.  Until next time, make sure you check out all of the NASA field campaigns here at the Earth Observatory website.

http://www.ioccg.org/reports/report7.pdf

http://www.ioccg.org/reports/WOC_brochure.pdf

http://www.esa.int/Our_Activities/Observing_the_Earth/ESA_s_sharp_eyes_on_coastal_waters

http://www.esa.int/Our_Activities/Observing_the_Earth/New_ESA_project_supports_aquaculture

http://ocean.si.edu/gulf-oil-spill

http://www.nasa.gov/topics/earth/features/oil-spill-video.html

http://www.nasa.gov/topics/earth/features/oilspill/index.html

http://oceanservice.noaa.gov/hazards/hab/

South Pacific Bio-optics Cruise 2014: The Pacific or “Peaceful” Ocean

April 24th, 2014 by Aimee Neeley

The global ocean is made up of five major ocean basins: the Pacific, Atlantic, Indian, Southern and Arctic Ocean. The Pacific Ocean is the largest of these basins as well as the deepest.  Its expanse runs 155 million square miles and contains “more than half of the free water on earth.” Not only is it the largest and deepest ocean basin, but it is also the oldest, comprised of rocks that have been dated to be 200 million years old.  You may have heard the term “Ring of Fire” associated with the Pacific Ocean. This name stems from the fact that the Pacific Ocean is prone to earthquakes and formation of submarine volcanoes along its extensive ridge and trench systems.

Ring of Fire http://oceanexplorer.noaa.gov/explorations/05fire/background/volcanism/media/tectonics_world_map.html

Ring of Fire
http://oceanexplorer.noaa.gov/explorations/05fire/background/volcanism/media/tectonics_world_map.html

The Pacific Ocean gained its name in the 16th century from the Portuguese navigator Ferdinand Magellan. Magellan and his crew set sail from Spain in 1519 in search of the Spice Islands located to the northeast of Indonesia. The Spice Islands were the largest producers in the world of spices such as nutmeg, cloves, and pepper. They navigated through the Atlantic Ocean and around the tip of South America after which they came across an unfamiliar ocean. He called this ocean ‘pacific’ which means peaceful.  Unbeknownst to them, they still had a long journey to the Spice Islands. You can learn more about the voyage of Magellan and his crew here.

Magellan's Voyage http://news.bbc.co.uk/2/hi/science/nature/6170346.stm

Magellan’s Voyage
http://news.bbc.co.uk/2/hi/science/nature/6170346.stm

OK, back to science! The CLIVAR P16S field campaign has entered the waters of the South Pacific known as a subtropical gyre. Gyre means “circular or spiral motion.” In the ocean, wind generated surface currents travel in a circular direction, either clockwise or counterclockwise, forming a large, circular body of water. The circular direction of the currents is caused by the Coriolis Force acting to deflect motion to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to the Earth’s rotation. The South Pacific gyre is located in the Southern Hemisphere, so winds and water are deflected to the left. Because of the deflection to the left, the gyre circulates in the counterclockwise direction, forcing water to pile up in the center of the gyre.  In the last post, “An Appreciation for True-Color Satellite Imagery” we discussed how microscopic plants, or phytoplankton, require nutrients to grow.  Blooms (large cell numbers) of phytoplankton cannot grow in these gyres because the water that piles up within the center of circulation is nutrient deficient.

Global Ocean Circulation  http://oceanmotion.org/html/background/wind-driven-surface.htm

Global Ocean Circulation
http://oceanmotion.org/html/background/wind-driven-surface.htm

We can use the information about the color of the light being absorbed and reflected by the ocean to deduce the concentration of phytoplankton biomass using the proxy Chlorophyll a.  Chlorophyll a is a pigment that both land plants and phytoplankton use to convert light to sugars in their chloroplast. Chlorophyll a absorbs strongly in the blue color of light. So when there is a lot of Chlorophyll a, then the light reflected back includes very little blue light. When there is very little or no Chlorophyll a, then a lot of blue light is reflected back. The figure below is an ocean color image based on the information I just described. The blue color represents little to no Chlorophyll a (or phytoplankton) present while the bright colors of yellow green and red represent increasing concentration of Chlorophyll a or phytoplankton biomass.

SeaWiFS  Ocean Color image, Pacific Ocean http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL

SeaWiFS Ocean Color image, Pacific Ocean
http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL

Please bear in mind that this explanation is very simplistic.  You can learn more about how ocean color works here.

See the image below for the current cruise track of CLIVAR P16S.  They are almost in Tahiti.  Just a couple more weeks…

Cruise Track, CLIVAR-P16S

Cruise Track, CLIVAR-P16S

ACKNOWLEDGEMENTS: NASA’s Ocean Ecology Laboratory Field Support Group is participating in the US Repeat Hydrography, P16S field campaign under the auspices of the International Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP).  The US Climate Variability and Predictability Program (CLIVAR), NOAA and the NSF sponsor this campaign.

4 logos from CCHDO sponsors

 

http://oceanexplorer.noaa.gov/explorations/05fire/background/volcanism/media/tectonics_world_map.html

http://oceanservice.noaa.gov/facts/biggestocean.html

http://oceanservice.noaa.gov/facts/pacific.html

http://www.iol.ie/~spice/Indones.htm

http://www.rmg.co.uk/explore/sea-and-ships/facts/faqs/what-and-where-are-the-spice-islands

http://news.bbc.co.uk/2/hi/science/nature/6170346.stm

http://www.merriam-webster.com/dictionary/gyre

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml

http://oceanworld.tamu.edu/students/currents/currents3.htm

http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?c=CHLOROPHYLL

http://oceancolor.gsfc.nasa.gov/SeaWiFS/

 

South Pacific Bio-optics Cruise 2014: An Appreciation for True-Color Satellite Imagery

April 18th, 2014 by Aimee Neeley

We have spent the last few weeks discussing the differences between inherent and apparent optical properties in the ocean and how we measure them.  Now let’s take a moment to appreciate the information these data give us.  I am sure many of you have seen satellite images of the ocean, hurricanes, etc. on the news and at other outlets.  A lot of work goes into each and every one of those images and they can show remarkable things on a global scale that would be difficult to detect through fieldwork alone.

Below you will see a true color image of a phytoplankton bloom in the Barents Sea that was acquired on August 24, 2012 by  NASA’s MODIS Aqua satellite . The Barents Sea is part of the Arctic Ocean and is located off the northern coasts of Norway and Russia. The word phytoplankton is Latin for plant (phyto) and to wander or drift (plankton).  Phytoplankton can photosynthesize and produce energy from sunlight just like plants do on land.  They also take up carbon dioxide and release oxygen like land plants.  Phytoplankton are an important component of the food chain as other organisms such as zooplankton and fish use them as a food source.  Additionally, they play an important role in the global carbon budget because they can use the carbon (CO2) that is absorbed by the ocean to make sugars.

Barents Sea  phytoplankton Bloom

Barents Sea phytoplankton Bloom

There are many types of phytoplankton that bloom in the ocean including diatoms, dinoflagellates, and coccolithophores, just to name a few.   You can learn more about different phytoplankton groups here.  They all rely on specific nutrients, such as nitrogen (NO3, NO2, etc.), phosphorous (PO4, etc.) and trace metals (iron, magnesium, etc.).  Phytoplankton blooms occur when many individuals, or cells, of one species are present in one region of a body of water (lake, estuary, open ocean), altering the color of the water.  In the image above, the water is dominated by a species of coccolithophore. Coccolithophores are a type of phytoplankton that are covered with plates made of calcite called coccoliths. Calcite, or calcium carbonate, is white giving that creamy white look to the water.  You can learn more about this coccolithophore bloom here.

This next image was recently featured on NASA’s OceanColor website. It was taken off the western coast of Africa where a current called the Benguela current flows northward bringing water from the South Atlantic and Indian Ocean.  In this image from April 10, 2014 we can see a yellow discoloration in the water.  I just learned that this area is prone to toxic hydrogen sulfide precipitation events that have been known to cause fish and other marine animal mortalities.  Amazingly, these events have been captured using satellite imagery.  However, the cause of this particular discoloration has not, as of this post, been determined.  This is where fieldwork comes in!  Still, it is very cool!  Thanks to Norman Kuring at NASA Goddard for locating this feature.

Discoloration in the Benguela Current off the coast of Namibia

Discoloration in the Benguela Current off the coast of Namibia

 

You can enjoy many other satellite images at NASA’s Visible Earth website.

 

References:

http://www.worldatlas.com/aatlas/infopage/barentssea.htm

http://aqua.nasa.gov/

http://earthobservatory.nasa.gov/Features/Phytoplankton/

http://www.bigelow.org/foodweb/microbe0.html

http://protozoa.uga.edu/portal/coccolithophores.html

http://oceancolor.gsfc.nasa.gov/

http://oceancurrents.rsmas.miami.edu/atlantic/benguela.html

http://visibleearth.nasa.gov/

http://oceancolor.gsfc.nasa.gov/cgi/image_archive.cgi?i=423

http://www.sciencedirect.com/science/article/pii/S0967063703001754

 

ACKNOWLEDGEMENTS: NASA’s Ocean Ecology Laboratory Field Support Group is participating in the US Repeat Hydrography, P16S field campaign under the auspices of the International Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP).  The US Climate Variability and Predictability Program (CLIVAR), NOAA and the NSF sponsor this campaign.

4 logos from CCHDO sponsors

 

Notes from the Field