Robert Oddo, July 13, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown 
July 11 – August 10, 2009 

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 13, 2009

Weather Data from the Bridge 
Outside Temperature 27.7oC
Relative Humidity 80.16
Sea Temperature 28.2oC
Barometric Pressure 1013.76 inches
Latitude 10o 21.11 N Longitude 52o 13.67 W

The replacement PIRATA Buoy

The replacement PIRATA Buoy

Science and Technology Log 

We have been steaming at full speed towards our first buoy. To the right you can see a picture of the replacement buoy that is on the back of the ship.  This buoy will be lowered into the water using cranes on the ship and then anchored in place. These buoys are anchored on the bottom of the ocean, which is very deep here in the Tropical Atlantic.  The ocean here right under this ship is 4,990 meters or 16,371 feet deep. That’s a lot of chain to attach to the anchor!!  A picture of the buoy instruments that will be redeployed are on the right.  There are other instruments that extend down into the ocean.

Personal Log 

Anchors for the buoys ATLAS buoy instruments that will be redeployed

Anchors for the buoys

I was wondering how we were going to deal with time as we traveled to the East.  A notice was put up yesterday telling us that we should change our clocks from 4 hours ahead of Greenwich Mean Time to 3 hours ahead of Greenwich Mean Time.  This ship has things going on 24 hours, so it is really easy to lose track of time and the day.

All in all, it is pretty comfortable on board and the people are very friendly. If you need to take a break from your work you can watch a video, read in the library, or sit out on the back deck of the ship.

Anchors for the ATLAS buoy instruments that to redeploy

Anchors for the ATLAS buoy instruments to redeploy

Cruise ship plan

Cruise ship plan

We change our clocks as we move east

We change our clocks as we move east

Robert Oddo, July 12, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown 
July 11 – August 10, 2009 

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 12, 2009

Weather Data from the Bridge 
Air Temp 27.5o C(81.5F)
Relative Humidity 76.63
Sea Temp 28.22
Barometric Pressure 1015.15 inches
Latitude 11o42.80 North Longitude 56o 07.33 West
Traveling at 10.7 knots

Setting up the lab

Setting up the lab

Science and Technology Log 

There is a lot of unpacking and setup that has to be done on a scientific cruise like this one. Researchers were busy today getting schedules setup, equipment working and orienting themselves to their workspaces. We are now steaming directly to 0o, 23oW to service a buoy in the PIRATA backbone that has not been transmitting data since 21 June 2009.

Yesterday, I wrote about PIRATA (Prediction and Research Moored Array in the Atlantic). Another project that is also going on simultaneously is the Aerosol and Ocean Science Expedition (AEROSE).  Saharan dust storms are estimated to inject three billion metric tons of mineral aerosols a year into the troposphere. The aerosols impact precipitation, fertilize the ocean, and change the air quality and impact ecosystems in the Caribbean and the US eastern seaboard. Red tides, increased rates of asthma and changes in precipitation in the eastern Atlantic and Caribbean have been associated with this dust from the Sahara. The data collected from this cruise will help us understand better the impact of his Saharan dust on the Caribbean and the US eastern seaboard.

Here I am out on the back deck.

Here I am out on the back deck.

One must be prepared for emergencies at sea and today we had an abandon ship drill and a fire drill. There are 49 people aboard the Ronald H. Brown and it is important to know what do in case of an emergency and make sure everyone is accounted for.

Personal Log 

We got underway from Barbados yesterday afternoon and the seas were described as being a bit “lumpy”.  I noticed little by little people seemed to disappear and was wondering what was going on and then it hit me.  Nausea, cold sweats and not being to get comfortable at all.  I got real sleepy and found a spot in the library and crashed for a couple hours. There is really no place to go. I woke up around dinner, took some seasickness medicine and hung out for the rest of the evening. Believe me, I was not the only one trying to get their sea legs.  There were very few people around. It takes time for the body to adjust to the rocking of the boat and some adjust faster than others.  This morning, I feel much better.

The course we have taken since we departed from Bridgetown

The course we have taken since we departed from Bridgetown

Sunset from the back of the ship

Sunset from the back of the ship

Robert Oddo, July 11, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown 
July 11 – August 10, 2009 

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 11, 2009

NOAA Ship Ronald H. Brown docked in Barbados

NOAA Ship Ronald H. Brown docked in Barbados

Weather Data from the Bridge 
Air Temperature 27.6o C (81.7o)
Relative Humidity 82.6%
Sea Surface Temperature 28.4oC (83.1oF)
Atmospheric Pressure 1014.8

Science and Technology Log 

The Prediction and Research Moored Array in the Atlantic (PIRATA) is project that is monitoring the upper ocean and near surface atmosphere of the Tropical Atlantic.  This is done by the deployment and maintenance of moored buoys and meteorological stations across the Atlantic. One of the purposes of this cruise is to do maintenance work on some of the buoys. The last couple of days have been spent loading equipment onto the ship and preparing the ship for this mission.

One of the science labs with equipment ready to be unpacked

One of the science labs with equipment ready to be unpacked

There is an incredible amount of preparation for a cruise such as this one. Scientific equipment must be packed carefully, shipped to the location where the ship is docked, and then unloaded and set up. If you forget something you might not be able to collect some of the data that you hoped to obtain. The data collected from this array of buoys will lead to a better understanding of an area of the Atlantic which is the main development region of tropical cyclones that threaten the United States.

Personal Log 

Arrived in Barbados late on the night of July 9th. Got to the R. H. Brown early on the morning on the 10th. Spent most of the day getting situated and meeting members of the scientific team as well as the crew.  Berths are small but comfortable.  I was surprised at all the amenities on the ship.  There is wireless Internet, a ship store, movies at 5:30pm and 7:30pm, laundry and even an exercise room with free weights, and elliptical and a treadmill. We attended an orientation session this morning regarding ship procedures, safety and general life onboard the R. H. Brown. 

Picture of my berth.  I have the top bunk.

Picture of my berth. I have the top bunk.

 Practicing getting in and out of immersion suits

Practicing getting in and out of immersion suits 

Robert Oddo, July 15-20, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown 
July 11 – August 10, 2009 

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 15-20, 2009

Weather Data from the Bridge 
Outside Temperature 24.19 oC
Relative Humidity 78.87
Sea Temperature 24.28 oC
Barometric Pressure 1016.0 inches
Latitude 00o 12.5 N Longitude 23o 37.28W

The CTD

The CTD

Science and Technology Log 

We have been steaming at around 10 knots(approx 11.5 mph) 24 hours a day to our first buoy. The scientists on board are preparing equipment for the work that awaits them once we arrive at our first stop, 0 degrees 01.0 South latitude, 22 degrees 59.9 West.  Replacement tubes for the buoys are being readied and the “CTD” is being prepared for deployment.  The “CTD” is the name for a package of instruments that is lowered in the water that includes sensors that measure conductivity, temperature and the depth of the seawater. Conductivity and temperature are important since salinity can be derived from these values.  The CTD is connected to the ship by means of a cable through which real-time data can be sent back to scientists on the ship as the winch lowers and raises the CTD through the water. The metal frame around the CTD has a number of bottles attached to it that collect seawater samples at various depths.  This water then can be analyzed back in the laboratory when the CTD is brought back on board. 

We have deployed a number of drifters as we are making our way to the first stop.  For the last couple of days, we have not been allowed to collect any data as we traveled through the territorial waters of Brazil. On the night of July 19th we launched an ozonesonde. An ozonesonde transmits information to a ground receiving station information on ozone and standard meteorological quantities such as pressure, temperature and humidity. The balloon ascends to altitudes of about 115,000 feet (35 km) before it bursts.

Deployment of the ozonesonde

Deployment of the ozonesonde

Personal Log 

A few days ago, I toured the bridge of the ship. There is always one officer on the bridge and also a person on watch. Unfortunately there is not a big wheel like I imagined up there to steer the ship (I always wanted my picture at one of those big wheels). But there are a number of thrusters that you maneuver the ship with.  There are also a number of radar screens that enable one to see surrounding objects and well as computers that allow the ship to run on different auto pilot modes. Before a radiosonde or a buoy is launched, one needs to inform the bridge and the operation is logged in. You really get a unique perspective of the ship from up on the bridge.

I have spent hours on deck watching for signs of life out in the ocean. We did have a pod of dolphins of our bow one day, flying fish seem to be out there all the time and one day we believe we saw a pod of false killer whales (maybe).  I expected to see some birds, but so far not one.

Here I am at the helm of the Brown.

Here I am at the helm of the Brown.

Research cruise plan

Research cruise plan

 

Dave Grant, November 16, 2008

NOAA Teacher at Sea
Dave Grant
Onboard NOAA Ship Ronald H. Brown
November 6 – December 3, 2008

MissionVOCALS, an international field experiment designed to better understand the physical and chemical processes of oceanic climate systems
Geographical area of cruise: Southeast Pacific
Date: November 16, 2008

Weather Data from the Bridge 
Sunrise: 10:16 UTC Sunset: 23:16 UTC
Wind: AM Slight; PM Slight
Seas: 4’
Precipitation: 0.0
Pressure: 1015

Science and Technology Log 

Flotsam and Jetsam “Never bring anything onto a boat that you can’t afford to lose.” (Nancy Church – Cape Cod Museum of Natural History)

Except for the anchor, there are very few items that go overboard intentionally on a ship. A hat blown off your head by the wind becomes flotsam, but something deliberately discarded is jetsamARGO  is the international program that deploys and monitors a global network of autonomous floats that monitor ocean conditions (“Taking the pulse of the oceans.”). The buoys are deployed from a variety of vessels and one of the main advantages is that a vessel does not have to slow down or stop to launch them. Because of this, a vessel dedicated to research is not required, and commercial and even cruise ships have participated in this world-ocean study.

Drifter currents

Drifter currents

Drifters have been distributed since 1999 and continuously monitor temperature, salinity and currents. They will provide a global network spread out on a 3º by 3º ocean grid (180-miles by 180miles). Data transmitted automatically to satellites is broadcast to the Global Drifter Program and available continuously to researchers.

Stickers on the drifter buoy

Stickers on the drifter buoy

Teachers and students also are involved through the Adopt-a-Drifter Program and we deployed drifters marked with decals from two schools partnered through it: Universite Nancy (France) and Grandview Elementary School – Grades K, 1, 2, 3, 4, 5. Drifters actively transmit data for over a year, but like anything in the sea, can become the home for bio-fouling organisms that can interfere with their operation. We deployed several of them. The simplest are blue-andwhite basket ball-sized floats with a drogue (a large sock-like bag) that acts as a sea anchor or drift sock so that the movement of the drifter is by current, not wind. Once in the water, the packing materials dissolve, the drogue sinks to about 15 meters, and the currents, satellites, scientists and students do the rest. All researchers have to do to explore the oceans is log-on to the drifter website with a computer.  

“After the sea-ship, after the whistling winds… Toward that whirling current, laughing and buoyant, with curves… (After the Sea-Ship – Walt Whitman)

Dave holding the drifter buoy

Dave holding the drifter buoy

Other larger drifters are shipped in sturdy but degradable cardboard cartons. These too are launched off the stern and the shipping boxes rapidly fall apart after the water dissolves the glue. They are rather mysterious since we did not actually see what they look like, but I’ve seen others in the repair shop at WHOI (Woods Hole Oceanographic Institution). They are tube-shaped and designed to automatically sink to as deep as 1000-meters, and then rise periodically to broadcast their data. What a wonderful journey they will have to share with the world when they start reporting their data in dark and stormy seas and on sunny days. Falling away astern of us, floating high and looking coffin-like, I was reminded of Queequeg’s casket and some of the most memorable lines from Moby Dick:  “These are times of dreamy solitude, when beholding the tranquil beauty and brilliancy of the ocean’s skin; one forgets the tiger heart that pants beneath it…”

Drifter array

Drifter array

Screen shot 2013-04-19 at 9.23.30 PM

Personal Log 

Drifter in the water on its way!

Drifter in the water on its way!

We have had a great string of days. I have settled into an interesting work routine with  helpful and interesting scientists and crew. Weather balloons and sondes are released every four hours and the readouts from their fights are very informative. Along with the evening lectures, the week has been like a short semester on meteorology. Hourly water sampling has gone well too, and we are learning more about these peculiar eddies of warm and cold water each day.

My roommate (RW) is very nice and accommodating, and since we work different hours and find the best way to relax is with headphones and a book, the room does not seem crowded at all. There are a few items I am glad I brought, and I suggest they be added to the TAS list: coveralls, ski cap, knee pads and eye drops. The coveralls are great for cool mornings on deck and to quickly pull on for the weekly “abandon ship” drills, since you are required to report to your muster station in long pants and sleeves, and with a hat. My light-weight volleyball knee-pads are good if I have to kneel on the metal deck for a while to take pictures. And eye drops are a relief since we do get wind almost every day, and some very bright days since we are headed into the Austral Summer, and the sun’s position is moving south every day.

Crew holding the Argos drifter

Crew holding the Argos drifter

I have been checking my Almanac, and perhaps as early as tomorrow, our course will cross paths with the sun’s southern movement, and it will be directly overhead at Noon. This can only occur at locations in the “Tropics” (Between the Tropic of Cancer and Tropic of Capricorn) and I have heard sailors refer to it as a “Lahaina Noon.” This term comes from the old sailing days when whalers made port stops at Lahaina on Maui. When it occurs there, fence posts, and for that matter, people, do not cast a shadow. Hopefully the clouds will clear around midday and we will be able to see the phenomenon.

“Thus drifting afar to the dim-vaulted caves Where life and it ventures are laid, The dreamers who gaze while we battle the waves May see us in sunshine and shade.” (Sun and Shadow by Oliver Wendell Holmes – 1857) 

Dave Grant, November 13, 2008

NOAA Teacher at Sea
Dave Grant
Onboard NOAA Ship Ronald H. Brown
November 6 – December 3, 2008

MissionVOCALS, an international field experiment designed to better understand the physical and chemical processes of oceanic climate systems
Geographical area of cruise: Southeast Pacific
Date: November 13, 2008

Gooseneck barnacles and Grapsid crab

Gooseneck barnacles and Grapsid crab

Weather Data from the Bridge 
Wind: AM Calm; PM 5kts
Seas: 5’
Precipitation: 0.0
Pressure: 1016

Science and Technology Log 

Big whirls have little whirls That feed on their velocity, And little whirls have lesser whirls And so on to viscosity. (L.F. Richardson)

This little imitation of Jonathon Swift’s ditty helps illustrate the parallels between the atmosphere and ocean. Just as in the atmosphere, but much slower because of the increased density, turbulence in the water is expressed by meandering currents, and vortices. Good examples of this are observable when an oar is dipped into the water to push a boat, or a spoon is drawn across a bowl of soup. One of the mysteries of the SEP (South East Pacific) region is the presence of large oceanic vortices (Eddies), the mechanisms that generate them, and the length of time they persist as identifiable entities slowly spinning in the surrounding waters.

Dave holding the UTCD

Dave holding the UTCD

In a number of coastal areas fishermen and oceanographers have discovered that some important fish species can be found associated with these so-called mesoscale water structures, like upwelling areas, meandering currents and eddies. Such links are fairly well known and heavily exploited in the vicinity of the boundary currents off eastern North America (Gulf Stream), California (California Current) and Japan (Kuroshio Current); for tuna, swordfish, sardines and anchovies. The coast of Peru and Chile is swept by the northward flowing Humboldt (Peru-Chile) Current and the area is famous for the upwelling that brings deep,  cold, nutrient-rich water to the surface (and every 5-7 years when it doesn’t, El Nino conditions). Exposed to sunlight, phytoplankton utilize the nutrients to form the base of the world’s largest industrial fishery for fish meal and oil. The area also supports a large commercial tuna fishery.

UCTD Data

UCTD Data

Poorly understood is the role of eddies that spin off the major current; vortices averaging about 50-Km (30-miles) wide (i.e. mesoscale). These may be either cold or warm water eddies that may last offshore for months, and move as discrete masses to the west. In general these vortices have more energy that the surrounding waters, circulate faster; and are important because they transport heat, masses of water and nutrients to less productive regions towards the mid-ocean. The eddies also transport marine life and the mechanisms for this are also poorly understood, however the outcome is not. Moored buoys out here collect and support masses of fouling organisms like goose-neck barnacles that must be cleaned off periodically, along with other routine maintenance of the batteries and recording instruments. Servicing these buoys is also part of the mission of the Ron Brown.

Chasing “Eddy”

CTD Data

CTD Data

Tracking these “cyclones in the sea” requires interpreting daily satellite images that measure water temperature and by data collected by the UCTD (Underway Conductivity Temperature Depth) probe. This is a torpedo-shaped device cast off the stern of the Brown while we are underway. It rapidly sinks to several hundred meters. Then, like a big, expensive ($15,000.) fishing lure, it is retrieved with an electric motor that winds back over 600 meters of line. The whole process takes about 20-minutes (including the 2minute plunge of the UCTD).

The information acquired is phenomenal, and if collected any other way, would involve stopping the ship and repeatedly lowering Niskin or Nansen bottles; and adding weeks or months to a cruise schedule. Once back onboard the ship, the data is downloaded and plotted to give us a continuous picture of the upper layers of the ocean along our sailing route. All of this hourly data allows the tracing of water currents. The procedure is not without trials and tribulations. Lines can tangle or break, and there is always the possibility that the probe will bump into something – or something will bump into it down in the deep, dark ocean. However, any data retrieved is invaluable to our studies, and each cast produces a wealth of information.

Teeth marks on a UCTD

Teeth marks on a UCTD

Personal Log 

Today’s weather is fabulous. Most mornings are heavily overcast, but we are still close enough to the coast to enjoy breaks in the clouds. So, everyone is taking their breaks in folding chairs on the foredeck at “Steel Beach” since we are never certain when we’ll again have a sunny moment, or how long it will last.

After lunch there was a bit of excitement; we saw other mariners. In the old days of sailing, ships passing each other at sea would often stop to exchange greetings, information and mail. This practice was known as gamming. We sighted our first ship of the cruise; a cargo carrier heading north and piled high with shipping containers. It was too far off for gamming or even waving (The scientists who are sampling air want to keep their instruments free of exhaust from any nearby sources)  so it would have been out of the question anyway. The bridge gave it a wide berth; so wide that even with binoculars I could not be certain of the ship’s flag, name or registry, other than oversize lettering on containers that spelled JUDPER. Presumably it was carrying agricultural goods from southern Chile or manufactured goods and minerals from the central part of the country. Chile is a major exporter of copper; and the smelters, factories and vehicles in this upscale corner of South America (And the sulfur and particulate matter they spew into the sky) are a interesting land signatures for the atmospheric scientists and their delicate instruments. So the only gamming today is in the narrow passageways throughout the Brown. There is no wasted space on a ship, so in many areas there is “barely enough room to swing a cat.” (The cat being the cat-o-nine-tails once used to flog sailors. “The cat is out of the bag” when someone is to be punished.*)

Group watching a ship on the horizon

Group watching a ship on the horizon

I am still not certain what the proper ship’s etiquette is in passageways and stairways, but I am quick to relinquish the right-of-way to anyone who is carrying something, looks like they are in a hurry or on a mission, or in uniform (obviously) or kitchen staff in particular. Because the ship is always rocking, I’ve found that I tend to lean against the right wall while moving about. By lightly supporting myself leaning with a hand, elbow or shoulder (depending on the how significant the ship is rolling, pitching or yawing) I slide along the wall, and probably look like a clumsy puppy scampering down the hall, but it works…except for a few bruises here and there. Often I come face-to-face with the same shipmates repetitively during the day. (How many times a day can you say “Hello” to someone?) Everyone is polite and considerate, especially when moving about the ship, and in spite of repeatedly passing the same people many times every day. So generally, since everyone is busy for most of their shift, when meeting in the hallways, you resort to awkward routines like: muttered Hey, Hi, Yo or What’s-up; tipping your hat or a dumb half-salute; or a nod…or if from New England, what is known as the reverse nod.

*Flogging: There was a science to this horrible practice, not only with the number of lashes imposed, but what they were administered with: a colt (a single whip) or a cat (They varied in size from “king size” to “boy’s cats”).

Although the U.S. admirals reported that “it would be utterly impossible to have an efficient Navy without this form of punishment” Congress abolished flogging on July 17, 1862. And the last official British Navy flogging was in 1882 – although the captain’s authority remained on the books until 1949. (To politely paraphrase Winston Churchill, the British Navy was bound together by…*#@#&!, rum and the lash.)

One Final Note 

We discovered stowaways onboard…two cattle egrets. Egrets are wading birds that feed in shallow ponds and marshy areas; and the cattle egret regularly feed along roadsides and upland fields where cattle or tractors stir up insects. Even when threatened, they tend to fly only short distances, so it is odd to see them so far from land. However, in the 1950’s a small flock of these African birds crossed the South Atlantic to Brazil and establish a breeding colony. I remember spotting them for the first time on the Mexican border near Yuma in the 1970’s and today they have managed to thrive and spread all the way across the warmer half of North America.

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… 
(Song for All Seas, All Ships – Walt Whitman)

Stowaways – cattle egrets

Stowaways – cattle egrets

Dave Grant, November 12, 2008

NOAA Teacher at Sea
Dave Grant
Onboard NOAA Ship Ronald H. Brown
November 6 – December 3, 2008

MissionVOCALS, an international field experiment designed to better understand the physical and chemical processes of oceanic climate systems
Geographical area of cruise: Southeast Pacific
Date: November 10, 2008

Weather Data from the Bridge 
Sunrise: 07:12 Sunset: 20:11
Wind: S-SW 8-10 Kts
Seas: S-SW 8-10’
Precipitation: 0.0
Temperature: 18º-C
Pressure: 1015 Mb

Science and Technology Log 

“Send them our latitude and longitude.”
Admiral William Halsey, 1944 (Response to an intercepted Japanese radio message: “Where is the American fleet?)

A Twin Otter plane flying over

A Twin Otter plane flying over

Now that we are out of sight of land and the ocean is featureless except for the waves, so pinpoint navigation becomes crucial. Using the most modern navigation tool – GPS (Global Positioning Satellite system) our navigation officer has put us precisely where we need be to await over-flights from aircraft sampling the atmosphere above us. We are not just near our sampling station – not a mile, a minute, a knot, or a league – we are within a hairsbreadth* of it. We will be here for the day taking water and air measurements, while waiting for the only things we’ll see flying over the Pacific besides birds and balloons; our last connection to the land for several weeks.

“Thanks for the memories.”

The CTD Rosette

The CTD Rosette

The ocean water we test has a memory for the weather and climate conditions today and over the last several months and years. The “code” we need to understand these secrets is hidden in the temperature and salinity of the water, and the keys to unlock them are a number of devices that sink, float and drift. Over the next few weeks we will use all these techniques to see what stories the water has to share. My first introduction to this remote sampling and sensing was a long-necked beverage bottle with a weight, retrieval line, and a cork that could be popped with a string. (And of course, duct tape to hold it all together.) Using it in the local pond and discovering that there were indeed differences between the surface and bottom temperatures was enough to pique my curiosity to move on to bigger things in college. This involved more sophisticated devices, typically named after the oceanographers that perfected them: Secchi, Nansen, Eckmann, Peterson and Niskin. All students of science and oceanography should study these pioneers and their struggles and achievements, but perhaps the foremost is Fridtjof Nansen (1861-1930)…arctic explorer, distinguished scientist and Nobel Laureate.

A storm petrel

A storm petrel

The Nansen bottle has been a standard water collection device since 1910 and when lowered by a strong line, can be signaled to close with a weighted “messenger” sent down the line to “fire” off a release mechanism that closes off a tube of water from any depth. The only limitation is the length of your line. Then that water can be brought to the surface for analysis of its physical features, nutrients and even contaminants washed into the sea or wafted from land. In 1966 Shale Niskin perfected a version of the bottle that today we will lower with eleven others on a circular frame called a rosette. These Niskin bottles can be signaled automatically to capture water at preprogrammed depths as the CTD device on the bottom of the frame records data. The CTD (Conductivity, Temperature, Depth) is one of today’s most important oceanographic tools. It is mounted on the rosette with the Niskin bottles and records the temperature and salinity of the layers of water, which allows oceanographers to trace the origins of the currents. The Brown has enough cable to lower it to 6,000 meters, but here in the Peru Basin, we are limited to less than 4,000 (Still deep enough to swallow any mountain east of the Mississippi, and most of the ones in the west.)

Data from the CTD cast

Data from the CTD cast

The crew does an amazing job holding the Brown on station, and can literally turn on a dime since the ship has fore and aft thrusters. When the seas are high and it is choppy, they maneuver into position by making a slow (right) turn to starboard (Where the rosette is deployed) so it is in the lee of the wind and much calmer. The turning creates a “pond” of flat water that also attracts seabirds, so I try to have my camera ready at all times. The whole process takes several hours and has to be done with great care and constant adjustments from the bridge since anything lowered over the side might become tangled with the rudder or propellers, its own cable, or otherwise be damaged or lost. The water brought up from depth in the Niskin bottle is collected for chemical analysis, salinity, dissolved oxygen and plankton samples. Nutrient bottles are quickly frozen for later analysis in the lab, plankton is preserved for identification under the microscope, and dissolved oxygen must be chemically tested immediately; so there is always a flurry of activity when the CTD finally is retrieved and in deck. Water on the surface is 18º and drops to 5º near the bottom. Salinity ranges between about 35.25 ppt on the surface and as low as 34.5 ppt at depth.

An NSF C-130 sampling information

An NSF C-130 sampling information

Personal Log 

There has been a good roll to the ship about every 10 seconds since we left port and after a few days your body anticipates it and I only notice the movement when I see water in a basin or the shower floor sloshing with it, or when something that is not secured bangs around. This movement approximates the wave period of the largest swells and they are generated by the constant winds drawn towards the Equator – the Trade Winds which merchant sailing vessels could always rely upon. In 1520, these same winds pushed Magellan northwest after crossing into the waters to our south that he called El Pacifico. When on deck, I have noticed a low and longer period swell from the west, which is a clue that there is some far off storm brewing. Or perhaps, since the Pacific is so wide, that like the light from distant stars, it has gone through its entire existence, dissipated, and its energy is just reaching us now…only a faint remembrance in the sea.

Screen shot 2013-04-19 at 9.20.33 PM

I’ll take note of things over the next few days and look for changes like the Polynesians did when watching for storms. Higher, shorter period swells indicate that the storm is approaching. This gives you time to prepare for the large, short period, wind-driven seas that challenge ships and sailors.

“Look not to leeward for fine weather.” J. Heywood, 1546

This sailor’s expression helps illustrate the fact that because winds are generated by the pressure gradient between high and low air masses, tacking into the wind moves you closer to fairer weather than running with it. (In actuality, the high pressure, and hopefully fair weather, is about 90º to the pressure gradient.) That doesn’t always explain waves however. Wave size is determined by wind speed, duration and fetch (the distance over which the wind blows), and over the broad expanse of the Pacific, there can be many storms and wind patterns creating waves simultaneously.

Before physicists and meteorologists fined-tuned the mathematics, sailors had their own theories about waves. One observation was that the size of seas (waves in a storm) could be estimated by the wind speed…a storm with 60-knot winds might produce 60-foot waves. People tend to overestimate wave size, especially when at sea, and the theoretical height is probably only about 80% of that figure (Still a very sizable and terrifying mass of water if you are in the midst of it!).

“Now would I give a thousand furlongs of sea for an acre of barren ground.” Shakespeare – The Tempest.

Another difficult aspect of wave behavior is estimating the velocity and distance between waves (wave period); and here we turn to the oceanographers and their experimental wave tanks. To try to understand waves at sea, it is much simpler to generate perfect swells in a controlled environment. Although wave behavior in a storm is chaotic and almost impossible to monitor accurately, there is good data on the swells that spread out from the fetch, and for that we turn to the ship’s “Bowditch.” (Nathanial Bowditch’s – American Practical Navigator).

So the 10 second swells rocking the ship are traveling at a speed of about 30-knots, and have a wavelength of over 500-feet; which means, among other things, smooth sailing for the Brown (and most of her passengers). I’ll continue to watch for signs of change and hopefully our fine weather will continue.

A breathtaking sunset

A breathtaking sunset