Monthly Archives: February 2012

Dave Grant: Horse Latitudes, February 22, 2012

Posted on by Dave Grant


NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 22, 2012

Weather Data from the Bridge

Position:26.30 N – 75.42 W
Windspeed: 0
Wind Direction: Calm
Air Temperature: 29 C
Water Temperature: 24 C
Atm Pressure: 1025
Water Depth: 4,410 meters
Cloud Cover: 0
Cloud Type: Slight haze

Science/Technology Log:

We are becalmed and even the veteran sailors onboard are remarking on how flat the sea has become. At about 30 degrees North and South Latitude, moist, low pressure air that was heated and lifted from the surface at the Equator has cooled and is now plunging back down to Earth, forming a line of light winds in a band across the sea. This dry, high pressure air becomes the Trade winds as it is drawn back towards the Equator along the sea surface in what is called a Hadley Cell (After its discoverer). We seem to be on the edge of this meteorological milepost, which was more than a nuisance in the days of sail. If stranded in its pattern too long, food and especially drinking water became an issue, and the first to suffer would be animals being transported from the Old World to the New. Legend has it that subsequent voyagers would come across their carcasses…hence the name Horse Latitudes.

While observing ships returning to port near his home, sixteen year-old future rock star Jim Morrison (The DOORS)  composed what is perhaps his most eerie ballot – Horse Latitudes.

“When the still sea conspires an armor
And her sullen and aborted
Currents breed tiny monsters
True sailing is dead
Awkward instant
And the first animal is jettisoned
Legs furiously pumping”

However, the stable ship makes deck work easier and I am catching up on samples under the microscope, including some of my own tiny “monsters” that the currents have bred.

“It is the astonishing variety of life that makes the sea such a fascinating
hunting ground. Get a tow-net, dredge and simple microscope,
and a new world is yours – a world of endless surprises.”
(Sir Alister Hardy)

The chief survey technician set me up  with his  flow-through seawater system and I can leave a net under it to continuously gather plankton. I have noticed some patterns already.
One: Phytoplankton is scarce compared to temperate waters off of New Jersey, and this helps account for the clarity and
brilliant blue color of the water. The absence of large rivers here adding nutrients to the system, and little coastal
upwelling,  means that there is little to fertilize plantlife.
Two: More accumulates in the nets at night, confirming that Zooplankton rises to the surface at in the dark. This diurnal
pattern of the plankton community has been well documented ever since biologists and fishermen went to sea.
Three: Also, there is much more plankton at the surface than in deeper water. This is no surprise since sunlight is the
key ingredient at the surface of this ocean ecosystem.
Four: Creatures from offshore tend to have a more feathery look about them than inshore species. This added surface
area may use the turbulence to help support them near the surface  and increase their buoyancy.

It is said:  “Turn off the sun, and the oceans will starve to death in a week.”  It is assumed that among other stresses on the Biosphere that accompany disastrous impacts of large asteroids, dust and ash from these rare collisions block out enough sunlight to stifle photosynthesis, causing Phytoplankton (The “Pasture of the Sea”) to waste away, and setting the stage for the collapse of the Food Chain and mass extinction events. Fortunately we have plenty of brilliant sunshine here and no celestial catastrophes on the horizon.

Some of the most interesting Zooplankton are the Pteropods, the Sea Butterflies.

   
Empty shell and live pteropod specimen
(Images on the Ron Brown by Dave Grant)

The renowned oceanographer Alister Hardy used them as indicators of different water masses flowing around the British Isles; and New England’s great oceanographer, Alfred Redfield correlated their drifting with the anti-clockwise circulation of water in the Gulf of Maine. Although most are small and less than an inch long, they feed on a variety of creatures and in turn become food for many others. In surface waters they gather phytoplankton, some utilizing cilia and mucus to sweep food to the mouth; but in deeper waters, others are carnivorous.

I am informed by our English colleagues that on Europe’s fishing grounds, they are sometimes fed upon by herring, cod and haddock; which is bad news for British fishermen, whose catch rapidly decays and is not marketable. Such fish are referred to as “black gut” or “stinkers.”

How concentrated are pteropods? Whales and seabirds that we hope to encounter later in the cruise are sustained by them, and in the warmer waters of the Atlantic, at relatively shallow depths and on the tops of submerged peaks at around 2,000 meters, R.S. Wimpenny reports considerable deposits of “pteropod ooze” from their descending shells, covering an estimated 1,500,000 square kilometers of the bottom of the Atlantic (An area the size of the Gulf of Mexico.). Like the Foraminifera, in deeper waters the aragonite in their shells (a more soluble form of calcium carbonate) dissolves, and other sediments like silicates from diatoms accumulate instead. Check out any oceanography text and you are likely to find a picture of this biogenic pteropod mud, as well as other types of deposits.

At least 90% of the animals in the ocean are meroplankton – spending time in this itinerant stage before becoming adults. This phase may vary from a few days to over a year, depending on the creature. (European eels larva are the long distance champions; for over a year, drifting from below us in their Sargasso Sea breeding grounds, all the way to rivers in Britain and France.)

Drifting larvae are cheap insurance for a species, filling the surrounding habitat with individuals of your own kind, settling in new areas and expanding ranges, and particularly, not lingering around their birthplace and competing with the parent stock. However, most individuals simply end up as food for other creatures that are higher on the food chain.

Not surprising, there are copepods, the “cattle of the sea” grazing on smaller organisms.

  
(Images on the Ron Brown by Dave Grant)

Calanus finmarchicus is sometimes called the most abundant animal in the world and is found throughout the oceans, sustaining many types of marinelife; even right whales and basking sharks off the coast of New England.

Other sea soup and children of the sea that author David Bulloch likes to call them, drift by me and swim circuits trapped by surface tension in the water drop under the microscope.

  
Radiolaria are single cell Protozoa that not only ensnare food with mucous, but harbor mutualistic algae
among their spines. (100 x’s)


More live pelagic snails. (Pteropod means winged foot.)

  
An empty shell with  copepod sheltered inside. Other skeletons filled with Paramecia, and a mixed sample of shells
and dust particles.  (Images on the Ron Brown by Dave Grant)

Now that is calm, everyone seems to have their sea legs and are comfortable talking about their bouts of mal de mer.
Here is the worst story about sea sickness I have come across:

 From Dave Grant’s collection of sea stories:
The world’s worst tale of seasickness.
As told by Ulysses S. Grant in his Memoirs

One amusing circumstance occurred while we were lying at anchor in Panama Bay. In the regiment there was a Lieutenant Slaughter who was very liable to seasickness. It almost made him sick to see the wave of a table-cloth when the servants were spreading it. Soon after his graduation [from West Point] Slaughter was ordered to California and took passage by a sailing vessel going around Cape Horn. The vessel was seven months making the voyage, and Slaughter was sick every moment of the time, never more so than while lying at anchor after reaching his place of destination. On landing in California he found orders that had come by way of the Isthmus [Panama], notifying him of a mistake in his assignment; he should have been ordered to the northern lakes. He started back by the Isthmus route and was sick all the way. But when he arrived back East he was again ordered to California, this time definitely, and at this date was making his third trip. He was sick as ever, and had been so for more than a month while lying at anchor in the bay. I remember him well, seated with his elbows on the table in front of him, his chin between his hands, and looking the picture of despair. At last he broke out, “I wish I had taken my father’s advice; he wanted me to go into the navy; if I had done so, I should not have had to go to sea so much.”

Poor Slaughter! It was his last sea voyage. He was killed by Indians in Oregon.

Dave Grant: Terra Nova, February 13, 2012

Posted on by Dave Grant

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 13, 2012

Weather Data from the Bridge

Position: 26.30N Latitude – 71. 55W Longitude
Windspeed: 15 knots
Wind Direction: South (bearing 189 deg)
Air Temperature: 23.2 C / 74 F
Atm Pressure: 1013.9 mb
Water Depth: 17433 feet
Cloud Cover: 30%
Cloud Type: Cumulus

Personal Log

After an uneventful flight from New Jersey and an eventful trip from the airport at Charleston and through security at the naval base (Taxi drivers don’t like to have their vehicles inspected…), I am setting up my bunk on the Brown. There is a skeleton crew since I have arrived early and everyone else is expected to report tomorrow. Crates of equipment are still being loaded, so it is advisable to stay off the outside decks, and after a quick orientation by every  ship’s most important crew member (the chef),  I will have the evening free to find my way around the ship and explore the dock.
First order of business: Pick up bedding from the laundry down below.
Next: PB&J sandwich (Since the galley doesn’t open until tomorrow).
Finally: Grab the camera to catch the sunset and an amazing assortment of cloud types.

South Carolina’s estuaries are noted for their fine “muff” mud and oyster banks and the tideline at the docks is covered with a dense ring of oysters. Besides filtering great quantities of water and improving its quality, oyster “reefs” provide a secure habitat for a myriad of marinelife, and food for many creatures. (As a frustrated oyster farmer in South Jersey once remarked: “There ain’t much that lives in the ocean that doesn’t like to eat oysters!”)

Oyster Chain

Oyster Chain

Comorant

Comorant

 

Grebe

Grebe

The prettiest bird around is the red-breasted merganser, another diving fish eater. Hunters nicknamed mergansers “saw-bills” since their bills have tooth-like notches for snaring fishes. The word merganser comes via Latin mergere meaning “diver” and “to plunge.” Curiously, one of my favorite students always mixes up the word and somehow it comes out as Madagascar (!).

(Images on the Ron Brown by Dave Grant)

The most secretive and uncommon bird around the piers is the pied-billed grebe. It also dives for its dinner, but on the bottom. When frightened (or pestered by a photographer trying to get close in the fading light) it discreetly sinks straight down and disappears like a submarine. Locally, this trick earned the grebe the nickname water witch, and by Louisiana sportsmen Sac de plomb (bag-of-lead).

Grackle

Grackle

By far the noisiest birds around and the only ones onboard, are boat-tailed grackles. The iridescent, purple-black males are hard to ignore when gathering for the night on our upper rigging. A common bird of Southeastern marshes; since the 1960’s boat-tails have been expanding their range north along the Eastern seaboard beyond Delaware Bay, and now breed all along the New Jersey coast. (A normal extension of their population, or perhaps a response to warming climate? Time will tell.)

Just before dark a peregrine falcon surprised me as it glided past the ship – undeniably the most exciting sighting of the day and a great way to end it.

 “Oh end this day,

show me the ocean.
When shall I see the sea.
May this day set me in emotion
I ought to be on my way”
(James Taylor)

Dave Grant: The Ship Was Cheered, the Harbor Cleared…, February 15, 2012

Posted on by Dave Grant

 NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 15, 2012

Weather Data from the Bridge

Position: Windspeed: 15 knots
Wind Direction: South/Southeast
Air Temperature: 23.9 deg C/75 deg F
Water Temperature: 24.5 deg C/76 deg F
Atm Pressure: 1016.23 mb
Water Depth: 4625 meters/15,174 feet
Cloud Cover: less than 20%
Cloud Type: Cumulus

Personal Log

Crew and scientists are reporting for duty and everyone is to be onboard by sunset for a scheduled departure tomorrow morning. There are many boxes of equipment to unload and sampling devices to assemble, so everyone is busy, even during meal times.

Tall ships had miles of rope and lines for handling enormous amounts of sail.
The Brown is also carrying miles of line and cable too, but not for sailing. This is coiled neatly on reels and will be used to anchor moorings of monitoring equipment that will record water temperatures and salinities for an entire year until they are recovered on the next cruise. These moorings are anchored with ship recycled chain and old railroad wheels and their long lines of sensors rising to the surface from 5,000 meters form the electronic “picket fence” spaced between Florida and Africa across the 26.5 degree North Latitude line we are sailing.

On our last night ashore we went downtown to enjoy dinner at one of the many nice restaurants in the historic district. It was a good time to update each other on different projects and make any last minute purchases. Everyone is anxious to get started. As captains like to say:

 “Ships and sailors rot at port.”
(Horatio Nelson)

Day 3 
We are leaving the dock on schedule and heading down river.

Old sailors’ superstitions say that a small bird or bee landing on the deck of a departing vessel foretells good luck on a voyage, and a tangled anchor line forecasts bad luck. Glancing around, I observe our noisy grackles preparing to depart neighboring ships at dock –  so I hope they qualify as small birds. And huddled out of the wind on deck is a crane-fly – not a bee, but a harmless bug that looks like a giant mosquito. Perhaps no guarantee of good luck, but since all our lines and chain are neatly stowed, I am confident that an old “salt” – seeing how ship-shape the Brown is – would concur that we shouldn’t unnecessarily envision any bad luck on our cruise.

Cranefly

Dolphin "X"

Sailing down river we receive a great treat and are guided to the sea by small groups of dolphins surfing underwater in our bow wave. These are Tursiops – the bottle-nosed, the most common and well-known members of the dolphin family Delphinidae. Tursiops is Latin for “dolphin-like.”  Their comradeship is another reassuring sign of good luck to suspicious sailors. It is a remarkable spectacle and entertainment to everyone, even the veteran crew members, who, like the ancient mariners, have reported it many times. Although they seem to be taking turns at the lead, one dolphin that keeps resurfacing has a small cross-shaped scar on the port side (Left) of the blowhole; proving that at least one member of the pod has kept pace with us for the entire time.

Ship mates. (Images on the Ron Brown by Dave Grant)

Curiously, they know to abandon us near the river mouth to join other “bow riders” that have caught the wave of a freighter that is entering the river and heading upstream. Noteworthy is the bulbous bow protruding in front of the freighter. Reminiscent of the bottle nose of a dolphin, the bulb modifies the way the water flows around the ship’s hull, reducing drag – which increases speed, range, fuel efficiency and stability – things dolphins were rewarded with through evolution. And what a show the dolphins make riding the steeper bow wave! Actually launching out of the vertical face of it like surfers.

Bow rider!

Passing historic Ft. Sumter we receive an impromptu lecture by some of the crew on Charleston’s rich history from the days of Blackbeard the pirate, up through the Civil War. There is an interesting mix of people on board, from several countries and with extraordinary backgrounds. There is also a great assortment of vessels using the bay – freighters, tankers, tugs, patrol boats, cranes, sailboats and a huge bright cruise ship. I am reminded of Walt Whitman’s Song for All Seas, All Ships:


Of ships sailing the seas, each with its special flag or ship-signal,

Of unnamed heroes in the ships – of waves spreading and spreading
As far as the eye can reach,
Of dashing spray, and the winds piping and blowing,
And out of these a chant for the sailors of all nations…

        

     

 I note a transition here from the river to bay ecosystems reflected in the birdlife observed. Grebes and mergansers are replaced by pelicans and gulls.

The bay mouth is protected from wave action by low rip-rap jetties, and outside of them in a more oceanic environment are loons, scoters, and our first real seabirds – northern gannets. Loons spend the summer and nest on pristine northern lakes like those in New Hampshire (Reminding me of the movie On Golden Pond) but migrate out to saltwater to winter in ice-free coastal areas.

Scoters (Melanitta) are stocky, dark sea ducks that winter over hard bottoms like the harbor entrance, where they can dive down and scrape mussels and other invertebrates from the rocks and gravel.

Gannets are cousins of the pelicans but much more streamlined. They too dive for food but from much greater heights, sometimes over 100’. They also plunge below the surface like javelins to snare fishes. They are wide-ranging visitors along the East and Gulf coasts, wintering at sea, and returning to isolated cliff nesting colonies known as a “gannetry”  in Maritime Canada

The ship was cheered, the harbor cleared,
Merrily did we drop,
Below the kirk, below the hill,
Below the lighthouse top.
(Coleridge)
 Sullivan Island lighthouse
Latitude: 32.75794
Longitude: -79.84326

The odd triangular shaped tower of Sullivan Island lighthouse originally had installed the second brightest light in the Western Hemisphere. (Said to be so powerful that keepers needed to wear asbestos welding gear when servicing the light)
At 163 feet, its unusual flash pattern is tricky to catch on camera, but it is our last visual link to the mainland, and it will be the only land feature we will see until we are off the lighthouse at Abaco, Bahamas, after ten days at sea. A lighthouse keeper at the lens room, watching us sail away, could calculate at what distance (in miles) we will disappear over the horizon with a simple navigator’s formula:

The square root of 1.5 times your Elevation above se level.
Try it out:  √1.5E’ = _____ Miles 

√1.5 x 163′  = _____ Miles  to the horizon

(Images on the Ron Brown by Dave Grant)
 

Dave Grant: Going “Blue Water”
, February 17, 2012

Posted on by Dave Grant

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 17, 2012

Weather Data from the Bridge

Position: Windspeed: 15 knots
Wind Direction: South/Southeast
Air Temperature: 23.9 deg C/75 deg F
Water Temperature: 24.5 deg C/76 deg F
Atm Pressure: 1016.23 mb
Water Depth: 4625 meters/15,174 feet
Cloud Cover: less than 20%
Cloud Type: Cumulus

Science/Technology Log

Sailors used to describe their trips as short-haul or coastal,
or “long seas” which also was described as going “Blue Water”


We are off to a great start after passing the harbor lighthouse and breakwater, and the seas are calm and winds gentle. The Low Country and barrier islands of South Carolina disappear quickly over the horizon, and the most striking change for me is the color of the water. As we have transited from the sediment rich waters upriver, to the estuary, and out to the ocean, its color has gone from grayish, to green to blue.

Bay/Estuary water in Charleston

Gulf Stream water

As a rapid indicator of what’s going on within it biologically, oceanographers use the color of the water. To quantify their observations for other scientist to compare results, a white secchi disc is lowered just below the surface and the observer compares the ocean’s color with tinted water in a series of small vials – the Forel-Ule Scale. (Francois Forel was an oceanographer and his end of the scale is the bluest; and Willi Ule was a limnologist and his end of the scale is darker, reflecting the fresh waters he studied.) The 21 colors run the gambit of colors found in natural waters and modified by the plankton community and range from brownish-to-green-to-blue. This gives you a quick measure of productivity of the waters and the types of phytoplankton predominating. For example: Diatom blooms are brownish and Dinoflagellate blooms form the notorious red tides. Clear, less productive waters look blue, and we are sailing into waters that are a deeper blue with every league we sail.

I lack a secchi disk and we can’t stop the ship to lower one anyway, so I am using instead a scupper on the side as a photographic frame to document this well-studied and interesting phenomenon.

“Being on a boat that’s moving through the water, it’s so clear.

Everything falls into place in terms of what’s important, and what’s not.”
(James Taylor)

Before departing on the trip I came across Richard Pough’s bird map of the Atlantic. On it he divides the ocean into 10-degree quadrants and indicates the average water temperature and number of birds he sighted daily. The good news is we are heading southeast into warmer waters. The bad news is, he does not indicate a very productive hunting ground for bird watching. For example, Cape Hatteras, NC, where the Gulf Stream skirts North Carolina, shows 40 birds. Off the highly productive sub-polar regions like Iceland where there are great breeding colonies of seabirds like gannets, he indicates scores of birds. Regardless, I am hopeful we will find some true seabirds to photograph on our voyage; and perhaps have some migrating songbirds drop in for a rest.

Gulf Stream sunset

Today, as our colleague Wes Struble discusses on his blog, we retrieved our first samples with the CTD rosette. Water is retrieved from predetermined levels between the surface and 4,500 meters sealed in bottles for salinity and dissolved oxygen analysis. These two physical features, along with temperature, are the benchmarks physical oceanographers rely upon to track the ocean circulation.

For an understanding of this process and an overview of the project, I met with Molly Baringer in her office – a large bench that the ship’s carpenter built on deck. It seats three and is similar to a lifeguard stand, so it can give a view of the water and fit over the [dis]array of equipment constantly being shifted around the fantail by various scientists and deck hands. With the calm seas and sunny weather, it is the perfect spot on the ship to sit with a laptop to outline daily assignments for all of us, review the mass of data streaming in, and relax to watch the sunset.

“When I am playful,
I use the meridians of longitude and parallels of latitude for a seine,

and drag the Atlantic Ocean for whales!”
Mark Twain

Scientists and crew prepare to retrieve a mooring before the next big wave!

Chief scientist Dr. Baringer is a physical oceanographer and so is interested less in the creatures moving around in the ocean and more about the water currents that are moving them around, and particularly the vast amount of heat that is transferred from the Equator to the Polar Regions by “rivers in the sea” like the Gulf Stream.

 Currents and storms in our atmosphere produce our daily weather patterns, which of course change seasonally too. Ocean currents work on a much longer time scale and the text book example of the turnover time of warm water moving Pole-ward, cooling and returning to the Tropics as “centuries.” This timeframe infers that dramatic fluctuations in climate do not occur.

However, by analyzing ice cores from Greenland, scientists recently have detected evidence of abrupt changes in climate – particularly a significant cooling event 8,200 years ago – that could be associated with vacillations in the Gulf Stream. Although lacking a blackboard at her impromptu lecture hall on deck, a patient Dr. Baringer was artful in walking me through a semester of climatology and modeling to highlight the implications of an oscillating Gulf Stream and its deepwater return waters – the Deep Western Boundary Current.

Surface water is driven from the southern latitudes towards the Poles along the western side of the Atlantic, constantly deflected in a clockwise pattern by the Earth’s rotation. Bathing Iceland with warm and saltier water and keeping it unusually mild for its sub-polar latitude, the Gulf Stream divides here with some water flowing into the Arctic Sea and the rest swirling down the Eastern Atlantic moderating the climate in Great Britain, France and Portugal. (This explains the presence of a rugged little palm tree that I once saw growing in a Scottish garden.)

Perturbations in the northward flow of heat by meanderings of the Gulf Stream or the smothering of it of it by lighter fresh waters from melting ice in Greenland and Canada appears play a significant role in occasionally upsetting Europe’s relatively mild and stable climate – which is bad enough. What is more alarming is new evidence that these changes don’t necessarily occur gradually over centuries as once assumed, but can take place rapidly, perhaps over decades.

There is more bad news. The surface of the sea is dynamic and even without wind and waves, there are gentle hills and valleys between areas. I remember my surprise when our physical oceanography teacher, Richard Hires, pointed out that because of warmer water and displacement by the Earth’s rotation, Gulf Stream waters are about a meter higher than the surrounding ocean…that to sail East into it from New Jersey, we are actually going uphill. If these giant boundary currents are suppressed in their movements, it will exasperate an ongoing coastal problem as those hills and valleys of water flatten, resulting in rising sea levels and erosion along northern coastlines.

This explains why we are “line sailing” at 26.5 North, sampling water and monitoring sensors arrayed on the parallel of latitude between Africa and the Bahamas. To measure change, it is necessary to have baseline data, and the stretch of the Atlantic is the best place to collect it.

Snap shots of the water column are taken using the CTD apparatus as we sail an East-West transect, but at $30-50,000. Per day for vessel time, this is not practical or affordable. Here is where moorings, data recorders and long-life Lithium batteries come into play. By anchoring a line of sensors in strategic locations and at critical depths to take hourly readings, year-long data sets can be recorded and retrieved periodically. Not only does this save time and money, it is the only way to generate the ocean of data for researchers to analyze and create a model of what is happening over such a vast region – and what may occur in the future.

For more specific details, check out the project overview.

Deep Western Boundary Current Transport Time Series to study:
-the dynamics and variability of ocean currents;
-the redistribution of heat, salt and momentum through the oceans;
-the interactions between oceans, climate, and coastal environments; and
-the influence of climate changes and of the ocean on extreme weather events.
Information at:  http://www.aoml.noaa.gov/phod/wbts/ies/index.php

We hear that “The package is on deck” and it is time to collect water samples from the 24 different depths the Niskin bottles were fired (Remotely closed). As any aquarist will assure you, as soon as seawater is contained it begins to change, so we always start with the bottom water and work around to the top water since dissolved oxygen levels can drop with rising temperatures and biological activity from planktonic creatures trapped along with the water samples.

Although as oceanography students we read that most ocean water is quite cold (~3.5C)  because only the top 100 meters soaks up the warmth from sunlight, it is still an awakening for me to fill the sample bottles with even colder bottom water. After a half hour of rinsing and filling bottles, my hands are reminded of the times I worked in an ice cream parlor restocking containers from the freezer and filling soft-serve cones. It is a delight to get to the last several bottles of warm (25C) surface water.

Once the DO and salinity bottles are filled, they are removed to the chemistry lab and the Niskins are all mine. By holding a small plankton net under them as they drain excess water, I try my luck at catching whatever has almost settled to the bottom. There is an extra bonus too. A patch of floating Sargassum weed that tangled in the rosette was retrieved by the technician and set aside for me to inspect.

Windrows of Sargassum weed drift past the Ron Brown

Here is what I found under the microscope so far:

From depth:

The bottom water is absolutely clear with no obvious life forms swimming around. However a magnification of 50x’s and the extra zoom of my handy digital camera set-up reveals a number of things of interest I am sorting into AB&C’s:
Abiotic: Specks of clear mineral crystals. Are these minute sediments washed from the mainland or nearby Caribbean islands? Or is it possible they are quartz grains carried from much greater distances, like the Saharan dust that satellite images have proven are swept up by desert winds and carried all the way across the Atlantic?

Biotic: Although I can not find anything living, the silica dioxide skeletons (frustules) of at least two species of diatoms are present. These fragile fragments of glass accumulate in deep sediments below highly productive zones in the sea and different species are useful to paleontologists for determining the age of those deposits. On land, fossil diatom deposits are mined for diatomaceous earth – used as an abrasive and cleaner, pool filter material, and even in nanotechnologyresearch applications. There is other detrital material in the samples, but nothing identifiable.

Celestial(?): One tiny round particle caught my attention under the microscope. It looks like the images I’ve seen of microtektites – glassy and metallic meteor particles that have been molded by the heat of entry into the atmosphere. The Draxler brothers, two science students in Massachusetts, collect them and I hope they will confirm my identification when I see them again.

Dust particle (Right) and foraminifera (Center)

From the surface:

The warm, sunlit surface water here is covered with Sargassum weed, a curious algae that sustains an entire ecosystem in the waters mariners named the Sargasso Sea. On board the Brown it is simply called “weed” in part because it can be a minor nuisance when entangled with equipment. The Sargassum’s air bladders that support it at the surface reminded Portuguese sailors of their sargazagrapes and they named the gulfweed after them.

Can you spot the two Sargassum shrimp next to the air bladder?

Floating Sargassum weed harbors a great variety of other creatures including baby sea turtles, crustaceans and especially bryozoan colonies. The film of life encrusting the weed is sometimes called aufwuchs by scientists and is a combined garden and zoo.

A quick rinse in a plastic bag revealed two species of bryozoan and numerous tiny crustaceans. The Phylum Bryozoa is the “moss animals” a puzzling colonial creature to early biologists. Bryozoans are an ancient group with a long fossil record and are used by paleontologists as an “index” species to date sediments.

Byozoan colony

To my delight there were also some foraminifera in the samples. “Forams” as they are called by researchers, are single celled protozoa with calcium carbonate skeletons. They are abundant and widespread in the sea; having had 330 million years to adjust to different habitats – drifting on the surface in the plankton community and on benthic habitats on the bottom.

It is not necessary for you to go to sea with a microscope to find them. I have seen their skeletons imbedded in the exterior walls of government buildings in Washington, DC; and our own lab building at Sandy Hook, NJ has window sills cut from Indiana limestone – formed at the bottom of the warm Mesozoic seas that once covered the Midwest. In the stone, a magnifying glass reveals pin-head sized forams cemented among a sea of Bryozoan fragments. Some living forams from tropical lagoons are large enough to be seen without a magnifier, and  are among the largest single-celled creatures on the planet. With a drop of acid (The acid test!) our Geology students confirm that our window sills are indeed made of limestone as the drops fizzing reaction releases carbon dioxide sequestered when the animal shell formed.

Living foraminifera eat algae, bacteria and detritus and are fed upon by fishes, crustaceans and mollusks. Dead forams make contributions to us by carrying the carbon in their skeletons to the bottom where it is sequestered for long geological periods.

Geologists also use different species of forams as “index” species to fix the date of strata in sediment cores and rocks. The appearance and demise of their different fossil assemblages leave a systematic record of stability and change in the environment; and paleoclimatologists use the ratios of Carbon and Oxygen isotopes in their skeletons document past temperature ranges.

Our first plankton samples extracted from the deepest samples retrieved from the Niskin bottles at 4,000 meters (2.5C) did not produce any forams. This may be because in deep, cold water, calcium carbonate is more soluble and the skeletons dissolve. Presumably why we identified only the glassy tests of diatoms.

Foraminifera shell at 100x’s

Tiny Paramecia swarm over the detritus in my slide and taking a closer look at that and the growth associated with the weed I am reminded of Jonathon Swifts jingle:

Big fleas have little fleas

Upon their backs to bite ’em

And little fleas have lesser fleas

And so, ad infinitum 


Sunset over the Sargassum Sea

The Chief Scientist:

A day in the life of our chief scientist involves: checking with her staff to evaluate the previous day’s collections, consulting with visiting scientists on their needs and any problems that might arise, checking with the deck hands and technicians about equipment needs and repairs, advising the ship’s officers of any issues, and making certain we are on course and schedule for the next station.

And then rest? Hardly!

Even when off duty there are inquiries to field from staff, scientists and crew; equipment repairs to be made; and software that needs to be tweaked to keep the data flowing.

How does one prepare for a career like this?
Physically: the capacity to function on little sleep so you can work 12-hour shifts and be on-call the other twelve. (And there is little escape at mealtimes either, where the conversation never stays far from the progress of the cruise.)Mentally: the capability to multi-task with a variety of very different chores.
Emotionally: the flexibility to accommodate people with many different personalities and  needs, while staying focused on your own work.
Also, excellent organizational skills, since months of planning and preparation are crucial.
And perhaps most importantly, a sense of humor!

 

 “Lock-and-Load!
Midnight shift.
Chief Scientist Dr. Molly Baringer prepares to fire the XBT
off the stern for an 800 meter profile of temperature and pressure.

Wes Struble: The Engine Room, February 24, 2012

Posted on by Wes Struble

NOAA Teacher at Sea
Wes Struble
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 24, 2012

Weather Data from the Bridge

Position: Windspeed: 15 knots
Wind Direction: South/Southeast
Air Temperature: 23.9 deg C/75 deg F
Water Temperature: 24.5 deg C/76 deg F
Atm Pressure: 1016.23 mb
Water Depth: 4625 meters/15,174 feet
Cloud Cover: less than 20%
Cloud Type: Cumulus

Science/Technology Log

Moving a ship through the water has come a long way since Ben-Hur was chained to a rowing bench as a Roman War Galley slave. I was interested in what systems powered the Ron Brown and Lt. James Brinkley was kind enough to take me on a tour of the ship’s engine rooms.

The Ron Brown has a total of six separate power units. Three of these are V16 (16 cylinders) diesel engines connected to electric generators.

Second Assistant Engineer Jake DeMello sits watch in the entrance to the engine room

These generators produce electricity to run the ship’s electric motors which turn the screws (propellers). In the past the diesel engines would have been connected directly to the propeller shaft, but in the last 20 – 30 years many ships have gone to using electric motors as an interface between the diesel engines and the propellers. On the Brown at any given time two of the V16 diesel engines are online running the generators while the third engine is held in reserve. These generators produce 600 volts of AC current. A transformer converts the 600 V AC to a DC current to run the ship’s large DC electric motors.

Image credit: nauticexpo.com
This image shows a diesel engine connected directly to the “Z” drive.
On the Ron Brown there is a generator and an electric motor between the
diesel engine and the “Z” drive.

A view of the main propulsion diesel engines of the Ron Brown. The V16 propulsion engines are in the foreground while the Ship Services V8 engines are in the background

Close-up of two of the V16 Marine diesels on the Ron Brown. For scale notice the flight of stairs behind the engines

Most ships have a propeller shaft that exits the rear of the ship parallel to the keel. The propeller is stationary – it can only rotate to propel the ship forward or backward. To turn the ship a rudder is employed which is usually controlled by a wheel on the bridge. The Ron Brown does not have a rudder; instead it is propelled by a “Z” drive. This type of propulsion system is specially suited for research vessels.  In a “Z” drive the main drive shaft from the electric motors comes out parallel to the ship’s keel. It then is joined to a type of “spline gear” and makes a 90 degree turn down. At this point the shaft exits the ship where there is another “spline gear” which turns 90 degrees again parallel to the keel.

NOAA Corps Officer Lt. James Brinkley stands next to one of the V16 "exhaust pipes" from the main propulsion engines on the Ron Brown

The region between the two “universal joints” is mounted on a kind of turn table which allows each of the screws (there are two – one on the starboard side of the ship another on the port side) to rotate 36o degrees. In addition to precise maneuvering, this system of two “Z” drives and a bow thruster, when interfaced with a computer control system and GPS, allows the ship maintain an exact position in the water to within a few feet or better.

The Ron Brown's inboard portion of the "Z" drive. The electric motor that propels the ship is at left. If you look carefully just to the left of center you can see the main drive shaft connecting the motor to the "Z" drive mechanism

The engine status monitor. Notice at the very top it indicates that Propulsion engines 1 & 2 are operating.

The Ron Brown has three other smaller V8 diesel engines that power generators that are used to provide electricity for SS (ship services). This would represent things like radios, heating & air conditioning, lighting, computers, etc. The electricity produced by these three generators goes through two step-down transformers. The first reduction drops the potential from 600 V to 480 V. The next step down brings it from 480 V to 120 V. This is the form that is available to power the equipment throughout the ship. In addition, these three smaller engines and their generators can be used to power the Ron Brown’s propulsion in case of an emergency.

NOAA Corps Officer, Lt. James Brinkley stands next to one of two cable spools, located in the stern of the Ron Brown, that contain 5000 meters of cable each. They are used for long distance towing. For scale Lt. Brinkley is 6'3".

I would like to thank Lt. James Brinkley for the tour and Second Assistant Engineer Jake DeMello for explaining some of the technical aspects of the engines and answering my questions.

Wes Struble: Get to Know the Scientists, February 21, 2012

Posted on by Wes Struble

NOAA Teacher at Sea
Wes Struble
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 21, 2012

Weather Data from the Bridge

Position: 26 deg 30 min north Latitude & 74 deg 48 min west Longitude
Windspeed: 11 knots
Wind Direction: 40 deg / NE
Air Temperature: 21.3 deg C/70 deg F
Water Temperature: 24.3 deg C/ 75 deg F
Atm Pressure: 1021.38 mb
Water Depth: 4500 meters/14765 ft
Cloud Cover: mostly clear with some clouds
Cloud Type: cumulus & statocumulus

Science and Technology Log

In a previous post I mentioned that two of the researchers I work with here on the Ron Brown are Shane Elipot and Aurélie Duchez. Both are originally from France but currently work for a UK government organization called NERC (Natural Environment Research Council). Shane works for the National Oceanography Centre in Liverpool and Aurélie works for the same governmental department but is stationed at their branch in Southampton. Both have earned Doctoral degrees in Oceanography.

Dr. Elipot and Dr. Duchez take a short break from their research to answer some of my questions

Dr. Aurélie Duchez attended high school in Nîmes, France until 18 years of age. Following high school she participated in 2 years of of grandes écoles (preparatory classes) held at her high school in Nîmes to prepare her for engineering school. From here she enrolled in an engineering school in Toulon (the ISITV) where she majored in “Applied Mathematics” with a specialty in fluid mechanics. This three year course of study not only involved normal class work but also included three different internships in the following order: A six week internship concentrating on computing, a two month internship in Miami, Florida working on breaking waves, and a six month internship in Grenoble, France studying ocean modeling in the South Atlantic. She remained in Grenoble and after three years earned her PhD by studying ocean modeling and data assimilation of the Mediterranean Sea. She secured a post-doctoral fellowship as a research scientist at the National Oceanography Centre, Southampton, UK where she currently works as an ocean modeler.

Dr. Duchez prepares some documents for her research in the Main Science Lab of the Ron Brown

Dr. Shane Elipot attended high school in France until 18 years of age majoring in the sciences. After high school he spent two years in preparatory classes to take the competitive entrance examination for the “grandes écoles” (France’s engineering schools). After being accepted, he majored in Electrical and Mechanical Engineering with a specialization in hydrography and oceanography. During this period he earned two masters degrees: Master of Advanced Studies in Meteorology, Oceanology & Environment and a Masters in Oceanography & Hydrography. He followed these with a PhD in Oceanography from Scripps Institute of Oceanography in La Jolla, California and the University of California, San Diego. Dr. Elipot currently resides in Liverpool, UK where he works for the National Oceanography Centre.

Dr. Shane Elipot monitors a CTD cast in the Ron Brown’s Computer lab during the early morning hours

Data acquisition hardware for the CTD in the Science Computer Lab of the Ron Brown

They are both serious and dedicated scientists who enjoy their work and they are also a pleasure to engage in conversation. I am glad to have had the opportunity to meet them.

I would encourage you to consider visiting the following websites:

Scripps Institution of Oceanography                http://sio.ucsd.edu/

Natural Environment Research Council            http://www.nerc.ac.uk/

Wes Struble: Arrival and Departure, February 19, 2012

Posted on by Wes Struble

NOAA Teacher at Sea
Wes Struble
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Sub-Tropical Atlantic, off the Coast of the Bahamas
Date: February 19, 2012

Weather Data from the Bridge

Position: 26 deg 30 min MN Latitiude & 71 deg 55 min Longitude
Windspeed: 15 knots
Wind Direction: South (bearing 189 deg)
Air Temperature: 23.2 deg C / 74 deg F
Atm Pressure: 1013.9 mb
Water Depth: 17433 feet
Cloud Cover: 30%
Cloud Type: Cumulus

Personal Log

With some minor travel changes in Seattle and a redeye flight into Charleston, South Carolina I arrived at NOAA Ship Ronald H. Brown at about 10:30 am Tuesday morning – tired but grateful. We left port mid-morning the next day and headed south/southeast. On the way out of port we were treated to a dolphin escort – five or six dolphins surfed our bow wave for half an hour or more. I share a stateroom with another teacher, David Grant. My stateroom  is comfortable and I will be sleeping on the upper bunk – a somewhat tight fit and something I haven’t done since my brother and I were sharing a room while we were in junior high school.

The Ronald H. Brown docked at the pier before our departure

David Grant, my fellow teacher-at-sea, working in our stateroom

A Dolphin escort off the bow of the Ron Brown as we head out of Charleston

The Ron Brown is the largest ship in the NOAA fleet. She was commissioned in 1997 and is named in honor of Ronald H. Brown, Secretary of Commerce under the Clinton Administration who died in a plane crash on a trip to Bosnia. With a length of just under 280 feet the Ron Brown has ample deck space for hauling all the various amounts of materials and equipment needed for a research cruise.  The ship’s captain is Captain Mark Pickett, the Executive Officer is Lieutenant Commander Elizabeth Jones, the operations officer is Lieutenant James Brinkley, the medical officer is Lieutenant Christian Rathke, with Ensign Aaron Colohan, and Ensign Jesse Milton making up the remaining officers. The entire ship’s complement is divided up between the NOAA Corps crew members, the merchant marines, and the science staff. For this trip we have approximately 50 people on board including the crew and the scientists.  From the science group there are four of us that will be dividing up the CTD watch: David Grant, Shane Elipot, Aurélie Duchez, and myself. As I mentioned earlier, David Grant is my Teacher at Sea colleague for this cruise. He hails from Sandy Hook, New Jersey which is considered the most northern sandy beach in the state. David teaches a variety of science courses at a community college. Shane & Aurélie are from France (although they both currently work in the UK for the Natural Environment Research Council).

A Coast Guard Ship shared the pier with the Ron Brown

The Arthur Ravenel Jr. Bridge over the Cooper River, Charleston SC - a fine example of a graceful Cable Stay Bridge

A view of the Arthur Ravenel Jr. Bridge from below as the Ron Brown passes under the bridge

A view of Fort Sumter - one of the icons of the War between the States

A mass of sargassum (floating seaweed) - from which we derive the name of this part of the Atlantic Ocean - the Sargasso Sea

After the Brown got underway we had the first of many drills. All of the science crew met in the main lab where one of the NOAA Corps officers, ENS Jesse Milton, reviewed the proper use of the rescue breathing apparatus, the Gumby suit, and the PFD (personal flotation device). When the meeting was over we had three practice drills: Fire/Emergency, Abandon ship, and Man Overboard. Each of these emergency situations has their own alarm bell pattern and all those aboard have particular responsibilities and particular muster stations to which they are to report.

A Fire/Emergency is identified by a long (10 seconds or more) continuous alarm bell. When the bell sounds everyone is to move to their assigned stations. The science crew is to go to the main lab and await instructions. If the main lab is actually where the fire or emergency is located our second muster point is the mess.

A series of short blasts (at least 6) followed by a long continuous blast indicates Abandon ship. When this alarm sounds you are to drop whatever you are doing return to your stateroom and retrieve your PFD and Gumby suit and report to your muster station. In addition to the life saving articles, you should be wearing long pants, a long sleeve shirt, and a hat (to protect you from exposure while drifting at sea in the life boat). For this emergency situation I am to report to fire station 15 with a number of other members of the crew and be ready to load into a lifeboat.

Three long alarm bells announce a man overboard. During this emergency different groups of people are assigned different positions around the ship to look for and point to the person who has gone overboard. When the floating person is spotted, all those on deck are to indicate the overboard person’s position by pointing with their outstretched arm. A person floating in the water produces a very low profile and can be very difficult to see from a small boat bouncing in the waves. If the rescue team has trouble locating the floating person they can look up at the ship and see where all the spotters are pointing. This can direct them toward the overboard person’s location.