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!

ORACLES in Namibia 2016: A Flight, a Sunset and a Traditional Namibian Braai

September 20th, 2016 by Mike Tosca

Field campaigns are hectic. Everyone is always thinking ahead to the next flight, rarely taking the opportunity to experience the, often times, incredible location they are operating from.

ORACLES has been no exception. On September 10, the ER-2 joined the P-3 in the sky, measuring aerosols and clouds from above. Since then, it has been a mad race to the finish: planning flights, analyzing data, fixing instruments, deliberating over last-minute plan changes, coordinating spatial coincidences between the planes mid-flight.

On flight days the ER-2 (the plane that the instrument – AirMSPI – that I work with, is on) has a “hands-on” call before the sun comes up. Meanwhile, the principal investigators spend 30 minutes discussing whether the plan they spent hours devising the day before will hold up in the face of an unpredictable environment. At 6 a.m. (or thereabouts) there’s a call with the pilots where we discuss the plan for the day, and then the pilot is off to prepare for a long day. The aircraft is towed out to the tarmac and, eventually, around 9 a.m. the plane – complete with a pilot in a spacesuit – is off for a full day of science-ing.

The ER-2 aircraft preparing for a flight, as seen from the “chase car”. Credit: Mike Tosca.

The ER-2 aircraft preparing for a flight, as seen from the “chase car”. Credit: Mike Tosca.

In addition to all of the above, we’ve also been mentoring an exceptional group of seven Namibian and South African interns. Their eagerness to learn has been inspiring. Life-affirming is hardly a strong enough word to describe how the experience has affected me.

Namibian interns in front of the ER-2 aircraft, checking out our instrument: “AirMSPI”. Credit: Walvis Bay airport employees.

Namibian interns in front of the ER-2 aircraft, checking out our instrument: “AirMSPI”. Credit: Walvis Bay airport employees.

Amidst all of the commotion, the stress, the anxiety, the data-crunching, the ever-elusive “hard down day” appears out of the ether, a seeming ray of light emerging from an overcast Swakopmund sky. Monday, September 19 was one of those days. And it proved to be one of those ephemeral times when the hard working scientists were able to explore a bit of the region of the world they have called home for four weeks.

We all were treated to a truly Namibian experience. One of our amazing interns took us to “the location”- a suburb of Swakopmund where the paved roads and German-inspired buildings of the town center gradually morph into smaller residential dwellings and dusty streets on their way toward the vast Namib desert. Children play in the streets, music echoes out of lively bars, neighbors laugh and talk together over their fences. We all shared a traditional Namibian meal of Namibian chicken, tripe, spinach, “pap”, smashed beans, Windhoek beers, and of course, a delicious “braai” (a Namibian and South African type of barbecue) at the accommodating Hafeni Restaurant. The braai was even cooked by hand by our intern Ismael in the backyard of the restaurant. Suffice to say, our tummies were very satisfied at the end of the day.

A group of hungry scientists outside Hafeni Restaurant in the Mondesa neighborhood of Swakopmund. Credit: restaurant staff

A group of hungry scientists outside Hafeni Restaurant in the Mondesa neighborhood of Swakopmund. Credit: restaurant staff

Our talented intern, Ismael, cooking us a traditional Namibian braai. Credit: Mike Tosca

Our talented intern, Ismael, cooking us a traditional Namibian braai. Credit: Mike Tosca

It was one of those experiences I’ll never forget. Kind of like the sunset every night over the Atlantic Ocean from Swakopmund Beach. Or being one of the first people to see the imagery that our remote-sensing instrument has collected from the previous day’s flight.

A dusty, smokey, sunset over the Atlantic Ocean from the Namibian coast. Credit: Mike Tosca

A dusty, smokey, sunset over the Atlantic Ocean from the Namibian coast. Credit: Mike Tosca

Beaufort Gyre Exploration Project 2016: Searching for Sea Ice: The 2016 Beaufort Gyre Exploration Project: Searching for Sea Ice

September 20th, 2016 by Maria-Jose Viñas

By Alek Petty

Your blogger, Alek Petty, out on the ice during the 2014 Joint Ocean Ice Study research expedition, with the Louis S. St. Laurent in the background.

Your blogger, Alek Petty, out on the ice during the 2014 Joint Ocean Ice Study research expedition, with the Louis S. St. Laurent in the background.

Hello and welcome to my new blog. I’m Alek Petty, a sea ice scientist at NASA’s Goddard Space Flight Center, currently making my way to the northern coast of Canada (a small town called Kugluktuk) to embark on the 2016 Joint Ocean Ice Study (JOIS) – a research expedition around the Arctic Ocean’s Beaufort Gyre. The Beaufort Gyre is a slowly-rotating icy body of water north of Alaska (see map), which covers an area roughly ten times the size of Lake Michigan and stores a significant fraction of the Arctic Ocean’s freshwater.

Cruise tracks from previous JOIS expeditions during 2006-2014 and the sea ice concentration around this year's summertime minimum extent on Sept. 10 (from NSIDC).

Cruise tracks from previous JOIS expeditions during 2006-2014 and the sea ice concentration around this year’s summertime minimum extent on Sept. 10 (from NSIDC).

The expedition I’m going to be on has occurred every summer since 2003 – coinciding with the Arctic annual sea ice minimum, which typically happens in September – providing us Arctic scientists with a unique opportunity to monitor this harsh, but climatically significant region. The goal of these expeditions is to better understand the Beaufort Gyre’s circulation, freshwater content, water mass properties and biota distributions. I’ve been lucky enough to be invited on my second expedition to support this year’s planned sea ice observations.

We will be taken around the Beaufort Gyre by the Louis S St. Laurent, a Canadian Coast Guard icebreaker specially designed to smash its way through the sea ice covered oceans (sea ice can be several meters thick in places). About a week ago, we observed this year’s sea ice minimum, which tied 2007 for the second lowest on record. The Arctic sea ice declines over the past decades have meant yachts and even a luxury cruise liner (with the aid of an icebreaker, they often leave that bit out in the news stories) are now navigating through the southern Arctic Ocean, including the newly opened Northwest Passage  – made famous by Franklin’s failed traverse back in 1845 (when the ice was a lot thicker) and commemorated in this heartfelt tune  by Canadian folk singer Stan Rogers.

While the diminished Arctic sea ice cover has made navigation easier than it used to be, especially for icebreakers, one of the primary objectives of our expedition is to deploy buoys into the ice that can collect measurements of the sea ice-atmosphere-ocean system as they drift through the Arctic Ocean (ice-tethered profilers). One of our initial goals will therefore be to search for sea ice thick enough to ensure that the ice isn’t going to melt out any time soon. One of my primary activities over the next few weeks will be to observe the extent and magnitude of sea ice freeze-up as we make our way north, the days begin to shorten, and the temperatures start to drop.

I look forward to giving you a better overview of what the trip is all about in future blog posts (we’re not just scouting for polar bears, promise), including some background to all the various scientific projects being undertaken. Stay tuned!

Notes from the Field