US GO-SHIP is part of the international GO-SHIP network of sustained hydrographic sections, supporting physical oceanography, the carbon cycle, and marine biogeochemistry and ecosystems. The US program is sponsored by US CLIVAR and OCB. Funded by the National Science Foundation and NOAA.

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S4P: 17 FEB 2011 (LETTER) Sep 30, 2013

Dear Family, Friends, and Colleagues,

Greetings from Antarctica! Our team traveled from our homes first to Christchurch, New Zealand, where we assembled and enjoyed the sunny weather and green gardens before our trip south. We had been told ahead to pack a “boomerang bag” which we would take with us if our flight to Antarctica was turned back en route by fast-changing Antarctic weather, because we would not get all our luggage back until we finally made it to Antarctica. (We found out that the record for consecutive boomerangs was seven!) We had also been told that certain items were required in our carry on bags, which had to fit under our seats. We thought these were one in the same so were quite relieved to be told during the pre-flight briefing the day before our flight that the boomerang bag was just one of our checked bags.

Our 5-hour flight from Christchurch to McMurdo was on a US Air Force C-17 transport. The flight was smooth (and noisy - we wore ear plugs), and the bag lunch they gave us enough for two. We got to take turns going into the cockpit to take photos of Antarctica from the aircraft. The landing was super-smooth and then, Wow!, we stepped out and found ourselves on this giant ice sheet in Antarctica, with a smoking Mt. Erebus in the background! The US Antarctic Program (USAP) staff took us in large polar transporters across the ice sheet and then around roads to the McMurdo base. On the way we saw penguins, seals, the New Zealand base, and more great bleak Antarctic scenery. We had a quick orientation briefing, were issued room keys and linens, told where to get food and our luggage, and given a schedule for a few events we’d want to attend.

The large USAP McMurdo base resembles a clean, well-run polar mining town with about 1000 residents. There are no commercial activities, but otherwise it has just about everything you’d expect: dorms, a cafeteria (serving a variety of hearty food), a small store, post office, coffee house, bar, labs, gyms, support buildings ad infinitum, lots of heavy equipment, warehouses, fuel tanks, etc. Impressive attention is paid to waste management, recycling, and environmental stewardship, making it one of the cleanest towns on earth. There is a port - open only a very short time each year, and that only after break- in by a heavy icebreaker - with a man-made pier made of reinforced ice. There are hiking trails and historic sites. We had a guided tour to Robert Scott’s “Discovery Hut” from 1902, close by the base (seehttp://en.wikipedia.org/wiki/Discovery_Hut). While anyone can walk there, because we had a guide we were allowed inside, seven at a time. In the “freeze-dried” environment of Antarctica, everything down to animal carcasses awaiting skinning and boxes of supplies was just as it was, and is being left that way for the future.

Speaking of “freeze-dried”, that’s how we felt after walking back from the hut to the base into a stiff and very cold wind - evening air temperature had dropped to 5 degF - the term “wind chill” (in that case well below -20) was certainly appropriate! (In Christchurch the USAP issued us cold weather clothing, and we were glad we had it.) But for the most part temperatures have been in the teens, and today’s 23 degF and light winds make it feel almost balmy. Our ship, the research icebreaker Nathaniel B. Palmer, arrived yesterday morning and fueling began immediately. (The McMurdo base reverts to its 200-person winter status this weekend and the fueling crew needed to get done so they could head home.) The departing science party will be off the ship this morning, and we board and begin loading right after lunch today.

There have been many little hiccups along the way, and one giant one: Much of our “do not freeze” cargo was inexplicably left sitting out in sub-freezing conditions, despite being correctly and unmistakably labeled as “Do Not Freeze”. (There are procedures for this, beginning with a cargo plan before we even ship the items from our labs, and every group affected by this incredible blunder had followed instructions perfectly.) Even the ship’s “do not freeze” food was sitting out in the cold. One container of our DNF cargo was correctly kept above freezing, and by some miracle that contained the standards for salinity and carbon, without which we would have had to cancel the expedition. But the Argo floats - worth $500,000 - were not so lucky, and must be shipped back, unused. (They would have provided the first winter CTD casts from much of this region.) We will not know the extent of damage to our other programs until we begin measurements, but we are hopeful that we can work around most problems.

We have a very good team for this cruise. I enjoy the way everyone gets along together and can tell already we will work together well as one team. I met the Captain last night, and was impressed in every respect. Our on-board Raytheon Polar Services Corporation support staff are a good bunch. So prospects are good for our upcoming voyage. Last night we all unwound in the bar, and in a few hours we begin loading. I’ll report again when we leave port.

Best Regards,

Jim Swift

PS - Because I do not go onto the ship’s very limited email (james.swift.guest@nbp.usap.gov) until tomorrow, I can send lots of photos today from the McMurdo base internet:

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S4P Map Sep 27, 2013

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Trace Metals Sep 25, 2013

There is no dust over the Southern Ocean. Not enough for plants, at least. Most dust particles are soils dragged from the continents by winds. Antarctica is a desert, but the dirt there is locked under ice, and the winds that blow around Antarctica bring no dust to the surrounding oceans.

This poses a problem for phytoplankton; dust carries iron, a nutrient plants need to grow. In most oceans, plant productivity is limited by shortages in nitrate and phosphate, nutrients they use in abundance. In the surface waters of the Southern Ocean, however, scientists find an excess of nitrate and phosphate, which leads them to realize that productivity in the Southern Ocean is limited by the scarcity of iron.

It was different during the last ice age, when there was less CO2 in the atmosphere than now. One major difference between land and sea plants is that the latter can be buried in the ocean floor after death, removing CO2 semi- permanently from the atmosphere. Scientists believe that lower CO2 levels during past ice ages may be partly explained by more productivity in the oceans. Plant growth in the Southern Ocean is now iron-limited, so they reason that it must once have contained more iron. In the prevailing theory, colder and stronger ice age winds enabled dust from the continents to reach the outermost parts of the oceans. Plants thrived, taking more carbon into the ocean sediment when they died.

Climate change modelers make projections of atmospheric carbon amounts based on evidence from the past; according to Chris Measures, oceanography professor at the University of Hawaii, models that take the oceans into account “must include iron if they are to be at all realistic.” Last year, Measures spent 100 days at sea testing water for signals of aluminum and iron. In collaboration with Bill Landing of the University of Florida, he travels the oceans in search of trace metals derived from dust. As trace metal oceanographers, Measures and Landing have partnered with CLIVAR (climate variability)/CO2, a global project that seeks to understand why climate varies. CLIVAR/CO2’s oceanography project consists of research cruises that monitor changes to the basic properties of seawater. Trace metals are beyond the scope of “basic properties,” but Measures and Landing have received permission and funding to tag onto these cruises, which allows them to acquire data at the highest density yet.

On CLIVAR/CO2 cruise I8S, we see a surge in the fluorescence signal just off Antarctica, indicating more productivity. But why, in these iron-limited waters, is the productivity higher? Where is the iron from? Measures finds it unlikely that a mighty wind has deposited dust this far south. Instead, he posits that the iron is washing off the underwater continental shelf of Antarctica. As he suspects, a data map shows that there is more dissolved iron near the coast, and that levels of iron and productivity plummet as we enter the open ocean. With each sample of disintegrated dust, theories are constrained further until we are left with the truth.

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I8S Podcast: The CLIVAR Program and Location Sep 25, 2013

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By Pien Huang

One of the major improvements to the 4th report of the Intergovernmental Panel on Climate Change, is the use of better predictive models. In the six years since the publication of the third report, they’ve cleared up some uncertainty by scoring the performance of their models to real observations.

We’ll take you aboard the Roger Revelle, a research vessel of the Scripps Institution of Oceanography, to look at one of the first steps in climate change prediction – collecting real-time data on which models are based.

In the first of a four-part series, we’ll look one cruise, I8S, as part of a larger data collection program.

[waves; birds]

In February and March 2007, the R/V Roger Revelle spent six weeks sampling water from Antarctica to the west coast of Australia, under the direction of Captain David Murline and Chief Scientist James Swift. This transect is one of about sixteen that are monitored every ten years in the Climate Variability – CO2 Repeat Hydrography program, or CLIVAR for short.

CLIVAR was born out of the World Ocean Circulation Experiment, a one-time research project in the 1990’s that trolled the oceans and created a vertical profile of water properties throughout the oceans, such as temperature, density, and carbon and oxygen content. CLIVAR was developed to continue and to improve on the measurements of the World Ocean Circulation Experiment, to create an ongoing record of the oceans on a decadal scale. It is the start of a modern oceanographic record akin to the measurements taken by Charles Keeling, who put a sensor on a tower in Mauna Loa, and first alerted us to the rising levels of CO2 in the atmosphere in the early ’60’s.

Measuring the oceans is more involved. To do it right, you have to take a boat out, drop an array of bottles and sensors overboard, and haul them back up, processing water samples on-site. And then you repeat this, in our case, over 80 times. Each of these steps takes time, technology, and manpower, as well as a lot of money and planning. CLIVAR is an international program, and in the United States, it’s funded by the National Science Foundation and the National Oceanographic and Atmospheric Association (NOAA).

In the planning stages of CLIVAR, scientists at a convention took a beach-ball of the Earth, and drew in lines which they felt represented the world’s oceans. These lines have since been debated and pared down, but there is a randomness to their names. Chief Scientist Jim Swift, who was present at the meeting, has this to say:

Why, for instance, is this called 8South and 9N? There’s some – we’ll call it goofiness to the WOCE line numbers. I9 comes over here, and I9 south over her, I9N comes up here…it’s just scientists, you know, doing their thing.

All of these transects have a common purpose, but each individual cruise requires months of planning by the Chief Scientist, who tailors the trip to a particular region, and also accommodates add-on programs from other scientists. A day of shiptime on the Roger Revelle costs a minimum of $29,000. So whenever possible, the scientists collaborate to save on operational costs like shiptime, fuel, and labor.

What really sets I8S apart from other CLIVAR cruises is location. Because the transect starts in Antarctica, the trip departs from New Zealand and requires two weeks of travel time to its first sampling station. Chief Scientist Jim Swift discusses the planning:

So I got some historical ice information; well, there’s a lot of ice there in December, so December’s too early to start the cruise. But if I look at January, we’re getting a big reduction in the ice, and by February, that’s the ice minimum. And oh, by March, it’s starting to grow in again. So the sea ice minimum in this region was in approximately overall February, so I told the ship scheduling people that the ideal for us was to reach this point at the ice minimum in early February.

Our cruise track, if transcribed on the opposite side of the world, would start with a two week steam across the North Atlantic, from the coast of France to Hudson Bay, and then a sampling route that runs south, down through the Great Lakes to Alabama, and then out to Bermuda.

In early February, we left port in Dunedin, New Zealand on a southwestern course, our ship laden with food and lab equipment for the next six weeks. We plunged through the Roaring ‘40’s which are followed by the Roaring ‘50’s, latitude zones that are located in the only place in the world where there is infinite fetch. Fetch refers to the distance a wave can travel before it breaks; the further a wave has traveled, the more energy it has. The waves in the Roaring 40’s and 50’s are caught in the Antarctic Circumpolar Current, and can theoretically travel in a circle around Antarctica forever. The waves don’t break, but they produce colossal swells. Luckily, Captain Murline’s steady course keeps seasickness to a minimum, and cribbage tournaments keep us occupied through the worst of it. We are well-rewarded when we cross over the Circumpolar Current.

Josh Green reads from the blog of Joe Ferris, second-mate:

When you get so far south the wind dies down and the clouds part and you have beautiful days from the high pressure system that always sits over the continent. Also great long sunsets and sunrises. Getting here we haven’t seen the sun for two weeks, and lots of fog. [But] now [that] we are here and its amazing, we…turn around and starting working our way back north.

Along with the sun, the proximity to Antarctica brought icebergs in all shapes and sizes, from those you could net with a fishing net, to entire islands that dwarfed our ship. It was a treat for the passengers, but a strain on the crew.

Second mate Joe Ferris, whose responsibilities include navigating the night watch, writes:

Today rates as one of the most intense 4 hour watches of my 8 year career at Scripps Institution. While driving a north-westerly line…we again ran into the ice edge. From the satellite maps we knew to expect it somewhere in the vicinity…but the ice edge today was blown and dispersed seaward from southerly winds… we approached the ice edge trying to see how close we could get and looking for a safe spot for a station. There was none, small bergs were everywhere…[and] we spent a good three hours maneuvering around icebergs at close quarters to get out. Pretty spectacular stuff, except I really didn’t have much time to enjoy it since I was the one on the helm.

Still, manning the controls on the night watch has its perks:

Last night I was treated to a once in a lifetime display of Aurora Australis, otherwise known as the Southern Lights. We had a big storm all afternoon, but by midnight the sky cleared and off on the horizon a blank of clouds started glowing green. Suddenly the Aurora Australis developed into a wide band arcing and dancing across the entire sky. The bands were shifting between purple, pink, and green, and it all seemed so…close that it [felt like] we were in it…

I tried calling the labs but everyone was asleep, so I woke the chief scientist up and when he saw the show he called everyone else. Ten minutes later I had about 20 scientists on the bridge, they didnt see the best of show, but they got to view some bands develop and dance around for a hour before it completely died out.

For I8S Outreach, this is Pien Huang. Tune in next, when we explore the machines and robots of data collection, on-board I8S.

This broadcast has been supported by the National Science Foundation, the National Oceanographic and Atmospheric Association, and the Scripps Institution of Oceanography.

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Shrunken Heads Sep 25, 2013

It is necessary when sampling water, to go from surface water to far down deep in the water column. Sometimes the bottom sampling depth can be more than 5000 meters deep. That equals 500 atmospheres! This high pressure environment creates an irrefutable excuse to shrink heads! Styrofoam mannequin heads of course, as well as styrofoam cups. The intensity of the water pressure at low depths forces the styrofoam into a more dense form, resulting in a shrunken head or cup. These objects can be drawn on with markers, creating custom 3-D shrunken mementos. This has not yet been tried with a full size mannequin, to U.S. Hydro’s knowledge…

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