Eric Boget - Principal Engineer in the Ocean Engineering Department at the Applied Physics Laboratory, University of Washington (APL-UW)

Eric Boget.  Photo from the APL-UW Website

My name is Eric Boget and I am a Principal Engineer in the Ocean Engineering Department at the Applied Physics Laboratory University of Washington (APL-UW). I graduated from the U.S. Merchant Marine Academy and spent the early years of my career working as crew on merchant vessels, tugs and tall ships. I came to APL-UW in 1990 and was originally hired to manage and operate their small fleet of coastal research vessels.  In the mid-90’s, I began going to sea with various scientists from APL-UW in support of their oceanographic research programs.  Over the years, I’ve been involved with many different oceanographic systems and platforms, included: undulating towed bodies, moored systems, large acoustic arrays, Autonomous Underwater Vehicles (AUV’s), etc. These days, I spend about 3-5 months a year at sea and the remainder of my time in the office primarily working on design and analysis of oceanographic mooring systems and continuing to manage the APL vessels and scuba diving program.  I have been involved with the Davis Strait program since it began in 2004 and my primary focus has been servicing the oceanographic moorings. I look forward to this trip each year and really enjoy working in Greenland. 

Eric and the team deploy a mooring.  See the YouTube Time Lapse.

The primary focus of the Davis Strait program is to provide year-round measurements of the freshwater flux (liquid and ice) flowing from the Arctic through the Davis Strait into the Atlantic Ocean. As part of an integrated observing system, we have maintained 15 moorings in the Davis Strait; 6 central moorings across the strait, 6 smaller shelf moorings on the Greenland and Baffin Island shelves plus 3 off-axis acoustic source moorings.  In the beginning, the moorings were turned every year but 5 years ago we switched to a two-year cycle.  The moorings are instrumented with upward looking sonar to measure ice draft, conductivity-temperature (CT) sensors, acoustic doppler current profilers (ADCP) plus conventional current meters and hydrophones listening for marine mammals. Additionally, the central and off-axis moorings have 780HZ sounds sources (6 total) that provide a navigational array for under-ice glider operations.  The gliders are equipped with CT and oxygen sensors.  To compliment the mooring array and gliders, the program re-occupies over 100 CTD stations collecting data and water samples at each of these sites.  We’ve been fortunate to have partnered with Bedford Institute ofOceanography (BIO).  BIO manages the hydrological sampling and analysis effort and additionally provides instrumentation and mooring expertise. 

There have been a few innovative technologies developed during the program.  The gliders use the acoustic array to navigate under the ice in the winter.  They fly back and forth across the Davis Strait and are able to surface on the Greenland side where the warmer West Greenland current keeps this area ice free all or most of the year (See figure at bottom of post.  There are other areas in Davis Strait that remain ice free during the harsh winter months and are called polynyas).   The top of the moored array is at a depth of 104 m to avoid the majority of the large icebergs in the strait.  In order for us to sample closer to the surface (20 m), we developed the “ice cat” which consisted of one or more CT sensor attached to a polyethylene (PE) jacketed wire rope with some flotation at the top.  The ice cat wires are attached to the top of the main moorings using a 600 lb weak link.  The CT sensors communicated inductively through the mooring wire to a logger mounted on the main mooring.  If the ice cat gets caught in the ice, it will break the weak link instead of causing damage to the main mooring. Despite the loss of the instrument, we will have collected all of the CT data in the logger which remains attached to the main mooring.  In addition, development of a smaller hydrophone for marine mammal monitoring has been ongoing for the past couple of years.

(Thank you to Eric for being a good sport and contributing the text for this blog post!).

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The rescue craft is prepared for launch to
transport science staff to Sisimiut.

Today, our approach to Sisimiut Harbor was stunning  (BTW, and I did not know this, Sisimiut Harbour is the worlds northern most harbor that does not freeze over in the winter, attributable to the Western Greenlandic Current that brings relatively warm Atlantic water up the coast of Western Greenland).  A blue sky with high wispy clouds provided the perfect back drop for colorful houses dotting the rugged coastline with the snow capped mountains looming large over the second largest city in Greenland.  Just as the sun was peaking over the horizon, Eric and other members of the science party disembarked via a rescue craft held by a crane over the water. I'm told that they will enjoy a hike in the surrounding mountains followed quickly, I'm sure, by a nice meal and some socializing. 

The air was crisp and a slight breeze put blush in our cheeks as we snapped pictures and longed for just one step on shore.  As soon as the boat returned from transport of its human cargo, we were off once more, heading back into the now choppy waters of eastern Davis Strait.  We now make our way towards the western side of the Northern Labrador Sea Line where we will begin nearly nonstop CTD operaitons until our arrival in Nuuk on the 25th.

The view on approach to Sisimiut.  Wow!

Sisimiut sunrise. Not bad eh?

A Temperature section of the Northern Line from Baffin Island to Greenland (hot off the press).  Note the northerly flowing warm water attributable to the Western Greenlandic Current invading the shelf.  This is what keeps Sisimiut Harbor ice free during the winter.  It's all relative, the dark red is only 4 degrees so no need to break out the bikinis.