Beaufort Gyre Exploration Project 2016: Searching for Sea Ice: Into the Ice

October 3rd, 2016 by Maria-Jose Viñas

By Alek Petty

Working on thin Arctic sea ice.

Working on thin Arctic sea ice.

After five days of cruising through open water, it was clear we had to change course and venture further north to find ice. The satellite imagery was showing ice above 76-77 degrees North (we were around 74 degrees North), and the ice edge didn’t seem to be drifting south at any real speed. After another few days voyage northwards, we thus finally found ourselves entering the Arctic sea ice pack. This wasn’t exactly a scene from the Titanic; the transition from water to ice was a gradual one, as the ice cover evolved from millimeters or centimeters of newly forming sea ice (nilas and grease ice), to thicker, consolidated ice floes (maybe a meter or two thick; 3.3 to 6.6 feet), which caused the ship to lurch and shake as it broke its way through.

Early stages of sea ice growth: nilas (top left), pancake ice (top right), young grey-white ice (bottom left) and first-year ice (bottom right). The top photos are courtesy of Jean Mensa.

Early stages of sea ice growth: nilas (top left), pancake ice (top right), young grey-white ice (bottom left) and first-year ice (bottom right). The top photos are courtesy of Jean Mensa.

Once we were well within the ice pack, the Woods Hole team was keen to get out onto the ice and deploy some buoys. This would be my chance to get out on the ice too, as I was helping lead efforts to collect ice thickness measurements and ice cores, to better understand the characteristics (like salinity, density and age) of this year’s Beaufort Sea ice pack. The microbial and microplastic scientists were keen to join in and collect their own ice cores, too, enabling them to take a deeper look at what else might be hiding within the ice.

The Woods Hole team leader flew out with the helicopter pilot early the next morning to hunt for thick ice, and seemed to find an ice floe thick and stable enough for us to work on. I joined them on the first science flight out a few hours later to set out our survey lines and coring sites, before our cargo was carried over and the rest of the team members joined us. It was soon apparent that the ice wasn’t as thick as we had hoped.

I drilled a few quick holes and the readings all came in at around half a meter, just above what might be considered safe to work on. Our polar bear guard, Leo, wasn’t too happy with the conditions either and soon found a few good sized holes and cracks circling us. We were under strict orders not to stray from the group and to test the ice for stability as we moved ahead. I’ve previously used data from satellites, planes, and sophisticated computer simulations to estimate the thickness of Arctic sea ice. Yesterday, I estimated ice thickness by hitting it with a stick.

Danger ice!

Danger ice!

It wasn’t quite vertical limit, and the group rebuffed my idea of roping together for dramatic effect, but there were still a few hairy moments when the odd leg found its way through the ice. Despite the added element of danger, all operations completed successfully and we hitched a lift back to the ship later that afternoon with our ice cores in tow. The Woods Hole team was working until last light to get their buoys prepped and ready to drift off through the Arctic. It was a fun, adrenaline-filled day of science, but I’d prefer it if we could find some thicker ice to work on next time around.

Oceans Melting Greenland (OMG): Come Fly With OMG

September 30th, 2016 by Josh Willis

September 22, 2016

Light rain this morning in Svalbard, but we soon took off and left the clouds behind for bluer skies. Today’s plan was ambitious since ice cover was present at almost every drop point. Ice conditions ranged from loosely packed sea ice, to thick sheets with just a few cracks, to fast ice with no visible water anywhere to be seen. After seven probe drops with just four successful data returns, we found a small area of open water in the wake of a large iceberg pushing through the sea ice. Our eighth and final probe drop was successful. Tomorrow we fly to Thule tackling our most northern probes yet. Looking forward to the challenge.

 

September 24, 2016

OMG set out from Thule Air Force Base with clear blue skies and perfect weather for collecting data. With light winds and almost no clouds in the sky, we headed south to collect data in Melville Bay, along the northwest coast of Greenland. At the coast the terrain was dramatic and oftentimes steep. The pilots guided us with expert precision into the Upernavik Fjord as well as two others, where we collected data in front of key glaciers. We set a record today dropping 25 probes and getting good data from 22. Looking forward to a day off tomorrow before heading back out on Monday.

 

September 28, 2016

As Thule dug itself out from the remnants of this week’s storms, OMG found we had some company in our hangar. Our goal today was to complete the northwest part of the survey, an ambitious plan since it required successfully dropping 25 probes. Unfortunately, a thick layer of clouds prevented us from dropping the first few probes but we soon found some open water. Again, it was a beautiful day to fly with spectacular views of the clouds, ice, water, and rugged terrain. We cruised into numerous fjords collecting measurements in front of several key glaciers including the King Oscar Glacier shown here. All together we collected 23 good profiles from 26 probe drops before heading home. We landed in time for me to make it over to the world’s most northern radio station where the DJs were nice enough to have me on as a guest. They also let me bring my friend Dick Dangerfield. As our time in Thule draws to a close, I couldn’t be happier with our progress. Tomorrow it’s off to Iceland to finish the southeast part of our survey.

Watch more videos throughout the campaign here.

Beaufort Gyre Exploration Project 2016: Searching for Sea Ice: More Motion In The Ocean

September 27th, 2016 by Maria-Jose Viñas

By Alek Petty

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My journey up to the ship went smoothly and I even had time to observe the Northern Lights (Aurora Borealis) in full bloom during our overnight layover in Yellowknife (in the Northwest Territories of Canada). The following day, a Canadian Coast Guard helicopter transferred us from Kugluktuk airport onto the ship, and after another day spent refueling and replenishing the boat, we were finally on our way to the Arctic Ocean.

The Northern Lights.

The Northern Lights.

The Louis S. St. Laurent ice breaker.

The Louis S. St. Laurent ice breaker.

I actually spent the first two days of our polar expedition sat out on deck, enjoying the sunshine and views over the Amundsen Gulf. In the distance I could just about make out the mouth of the Mackenzie River delta – a key outflow of fresh and mineral rich river runoff into the Arctic. This shelf sea region is rich in wildlife, including beluga whales and even narwhals. We looked out eagerly, but only spotted a couple of lowly seals in the distance. Maybe on our way back we’ll have more joy.

On Saturday morning, we emerged into the Arctic Ocean proper —the Beaufort Sea! — where conditions were a bit less serene. In fact, one of the consequences of the diminished Arctic sea ice cover over the past decades has been an increase in Arctic Ocean waviness, as the lack of sea ice enables winds to more effectively whip up the ocean. Arguably one of the most distressing impacts of climate change for us unhardened scientists.

Despite the continued lack of sea ice, the water sampling exercises have begun in earnest. At each research station (a virtual station if you will, we just stop at a predetermined location in the ocean) a large metal carousel with various water samplers attached —a rosette, as we call it— is released, profiling the water column as it sinks to the bottom of the ocean, before being hauled back up to the ship for analysis.

A rosette deployment.

A rosette deployment.

There are around 50 stations in total that we plan on hitting during this expedition. The various scientists on board all have their own things their looking for in the water —plankton, bacteria, alkalinity, dissolved inorganic/organic carbon, micro-plastics (yep, they make it to the Arctic Ocean too), etc. You name it, we’re sampling it.

One of my tasks, along with Japanese scientist Seita Hoshino, is to profile the water column in-between theses stations using XCTD (eXpendable Conductivity Temperature and Density) probes. XCTDs provide a quick and cheap (well, about $800 per probe, so not that cheap) real-time analysis of the temperature and salinity of the water column while the ship is moving. I’ll try and show you an example profile in a later blog post.

We’re hoping to hit some ice soon, as for us ice observers there’s not a whole lot for us to get really excited about yet. It’s quite the contrast to the cold, icy conditions of my 2014 expedition thus far…

 

Oceans Melting Greenland (OMG): Swoosh

September 21st, 2016 by Josh Willis and Laura Faye Tenenbaum
NASA's G-III about to take off from Kangerlussuaq Airport for a day of ocean science research.

NASA’s G-III about to take off from Kangerlussuaq Airport for a day of ocean science research.

Swoosh! It’s not a sound so much as a feeling. You feel it in your ears and through your whole body. And everyone on the plane — two NASA G-III pilots, two flight engineers and the rest of the Oceans Melting Greenland (OMG) crew—feels it at exactly the same time. It has become our inside joke.

The swoosh happens every time the flight engineers drop an Aircraft eXpendable Conductivity Temperature Depth (AXCTD)   probe through a hole in the bottom of the plane. The AXCTD comes in a 3-foot-long gray metal tube—with a parachute. After it hits the water, the probe measures ocean temperature and salinity from the sea surface down to about 1,000 meters. The tiny difference between cabin and outside pressure pushes the probe out and makes ears pop at the same time.

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The two images above show flight Engineers Phil Vaughn and Terry Lee ready to drop an AXCTD through a hole in the bottom of the plane.

The two images above show flight Engineers Phil Vaughn and Terry Lee ready to drop an AXCTD through a hole in the bottom of the plane.

Lead scientist Josh Willis prepares to mark the probe drop on his GARMIN GPS.

Lead scientist Josh Willis prepares to mark the probe drop on his GARMIN GPS.

This is the second week of our three- to four-week mission that will be repeated every September/October for the next five years. We’re finally starting to iron out all the minor details in our protocol. With so many moving parts, the protocol is important, and the intricate timing helps us make sure no one forgets any details and we get the most accurate record of when and where we drop each one.

All of us wear headsets so we can communicate with each other. Here’s an abbreviated version of how it all goes down:

  1. Project Manager Steve Dinardo announces “Data recorder ready.”
  1. Pilots Bill Ehrenstrom and Scott Reagan call out the cloud and ice conditions and the number of minutes to the drop site. Then they determine the altitude for the approach.
  1. Flight Engineers Terry Lee and Phil Vaughn announce “Tube positioned and ready.”
  1. At 50 seconds from the drop site, the plane slows down and cruises at about 5,000 feet.
  2. At 20 seconds, Lee and Vaughn open the cap of the tube—you know, the one with that hole through the bottom of the plane—and everyone’s ears pop (the first time). Protocol states that they announce “Tube open!” but since our ears just popped, we often hear “Well, of course the tube’s open” or “As you already know—tube’s open.”
  1. At 10 seconds, the pilots count down to 1 and say “drop.” The engineers reply “Sonde’s away” and we all feel that swoosh. There it is. Our ears pop for the second time as the AXCTD is “swooshed” down the tube and out through the hole in the bottom of the plane. (And yes, we all still look at each other with our sly smiles because it’s so much fun to say, “hole in the bottom of the plane.”)
  1. It is the swoosh, more than anything said during the lengthy protocol script playing through my headset, that tells me—OMG lead scientist Josh Willis—to mark the drop on my GARMIN, a GPS we use to record the location of each drop.
  1. After each drop, our aircraft banks steeply and we all silently celebrate the fact that we don’t get motion sickness. We continue circling during the six or so minutes it takes for the science probe to parachute down 5,000 feet to the sea surface and make its way through the water column, sending back data to us in real-time on the plane.

We circle until Dinardo says we’re done recording data, then it’s off to the next drop site.

During our many, often challenging hours on the plane together, we share these little inside jokes and laugh—not caring if anyone in the outside world thinks it’s funny. Seems like we are bonding. I couldn’t be happier.

A view of Greenland’s Southwest coastline out the window of NASA’s G-III modified aircraft. A view of Greenland’s Southwest coastline out the window of NASA’s G-III modified aircraft.

Salinity Processes in the Upper Ocean Regional Study (SPURS): SPURS-2 Initial Results

September 21st, 2016 by Maria-Jose Viñas

By Eric Lindstrom

The SPURS-2 science party on the R/V Revelle.

The SPURS-2 science party on the R/V Revelle.

The R/V Revelle expedition has been the opening round in a yearlong effort to understand the upper ocean physical processes in the eastern tropical Pacific. We put moorings in place to collect a time series of upper ocean measurements over the year. We launched the first round of Lagrangian drifters and floats. Lady Amber will be servicing these assets at regular intervals and launching new drifters and floats into the array.

It is with some caution and caveats that I try to summarize our findings from the last six weeks of effort. Ideas are still young and data processing is still in its early phases. Only data from shipboard measurements are complete but still require careful screening, calibration, and validation. Despite the caveats, some of our questions and challenges are much clearer now than before we left Honolulu.

The Conductivity, Temperature and Depth (CTD) work, led by Janet Sprintall, charting the variations of temperature, salinity, and oxygen in the upper ocean, revealed some quite interesting features. Janet and her team will be looking at salinity-compensated temperature inversions in the upper ocean that seem to be closely associated with the edges of the east Pacific fresh pool.

Jim Edson and Raymond Graham have a wonderful three-week time series of 80 atmospheric profiles from their radiosonde launches via weather balloons every six hours. Ray will be working these up for his MS degree research project, so I won’t steal any of his thunder. Needless to say, we all think he will have an awesome project because it is such a rich data set!

Ray also assembled all the rainfall data daily and found that during SPURS-2 we had about 10 inches of rainfall in our 3 weeks on site near 10N, 125W.

The women of SPURS-2.

The women of SPURS-2.

Carol Anne Clayson has collected more than 1,500 air-sea flux estimates (20-minute averages) to be analyzed in conjunction with the upper ocean data sets from numerous platforms. She has already been able to run her mixed layer model using initial conditions from early in the expedition and the raw flux estimates to compare with later expedition measurements. It gives us great optimism for new discoveries out of this data set.

Michael Reynolds brought the Remote Ocean Surface Radiometer (ROSR, from Andy Jessup) and the Infrared Sea surface temperature Autonomous Radiometer (ISAR, from Carol Anne Clayson) to SPURS-2 to examine the surface skin temperature of the ocean during rainfall. Michael successfully engineered the instruments for this purpose (normally a fair weather measurement). He has put together some exciting compilations of data comparing his measurements with other temperature measurements made on the ship.

Julian Schanze from Earth & Space Research in Seattle is the man with the Salinity Snake. It has provided a virtually continuous record of the salinity in the top 2 inches of the water column. Julian has identified nearly 40 fresh lenses where salinity at the surface is significantly lower than ship intakes at 6.5 feet (2 meters), 9.8 feet (3 meters), and 16.4 feet (5 meters depth). These measurements, when further combined with the Surface Salinity Profiler data from the upper 3.3 feet (1 meter), will constitute a rich data set for analysis of fresh water lenses induced by rainfall.

Ben Hodges from Woods Hole Oceanographic Institution (WHOI) has been following the three Wavegliders deployed near the SPURS-2 central mooring. They have salinity sensors near the surface and at 19.7 feet (6 meters) depth and will be hard at work over the entire coming year. One of the Wavegliders had an experimental package of sensors on it called the salinity “Rake” with sensors at every 3.9 inches (10 centimeters) depth from the surface to 3.3 feet. The Rake, invented by Raymond Schmitt at WHOI, recorded data internally and was recovered after a few days of operation to check functionality (it has not been to sea before). The data is amazing; but it only lasted one day before mechanical failure and short circuits took it out of commission. However, that vertical resolution and the interesting features that it saw were a new peek at the ocean surface salinity that really has not been seen before. More engineering work needs to be done at home before it can be re-deployed. The team at Woods Hole will be highly motivated to get this instrument to sea again soon, based on what we saw in just one day. The Waveglider was re-deployed without the Rake.

The Surface Salinity Profiler (SSP) team led by Kyla Drushka has a very successful run with 18 deployments (not counting various tests and trials). The data is still being assembled and examined but, like the Rake measurements, the SSP focus on the top 1 m of the ocean is going to provide new insights on ocean processes. The SSP has the added benefit of microstructure probes to provide information on turbulent mixing. The biggest difference in salinity seen over 3.3 feet by SSP was 9 units!

Eric Chan had the rare opportunity to focus a study on the air-sea exchange of carbon dioxide during rain events. The simultaneous analysis of his gas exchange data with the salinity snake and meteorological data will be enlightening. Certainly the raw carbon dioxide data show the dip in pCO2 expected during rain events when the salinity drops.

Andy Jessup, voyage chief scientist, at work.

Andy Jessup, voyage chief scientist, at work.

Finally, I’d like to heap praise on our chief scientist, Andy Jessup, who managed execution of all the projects and requirements with great skill and diplomacy. The whole SPURS-2 team owes Andy a great deal for making the R/V Revelle expedition such a successful initiation of the SPURS-2 Program.

Next blog post: PORT!

Notes from the Field