Month: November 2013

As we approached the third and final week of the voyage, I was beginning to fear that the lack of fresh vegetables and lettuce as well as limited sunlight might have a permanent effect on my psyche.  I also knew that that the chances of seeing Arctic wildlife were diminishing by the day.  So I was I was filled with mixed emotions as we wrapped up the research and began our journey home. Over the course of the trip, we had completed 13 CTD transects for 183 CTD casts and, as we headed back towards Dutch Harbor, the last few days of the cruise were spent relaxing and catching up on much needed sleep. I also finally got the chance to stand on the bridge and was lucky enough to spot several whales, most likely humpbacks, three pods of porpoise and two ringed seals, one of which was eating a large crab of it’s chest. The time also gave me the chance to reflect on how lucky I was to have had the opportunity to join the scientific crew aboard the Healy. Not many people can say that they have traveled above the Arctic Circle, cruised along the International Date Line, conquered the Gumby suit, witnessed the loss of sunlight at the rate of ten minutes/day, fallen asleep to the pitch and roll of 20 foot swells or listened to the eerie sound of miles upon miles of meter thick frozen ice being broken apart or dropped a personally decorated Styrofoam cup to the depth of 3,000m and seen it return as a perfect miniature of its original self, all while learning about and assisting with important scientific research.  Now that I am back on land, I can truly say that I will miss life onboard the Healy and would jump at the chance to return for another expedition. The experience was one that I am extremely grateful for and will be difficult to forget for all the right reasons. There are so many memories that I want to hold on to—some big, such as the confidence I built up in learning to operate the CTD or seeing the Northern Lights—others, small moments such as clumsily walking into a Conex box and scarring my forehead, thus giving inspiration for a hastily put together Halloween costume as a blind mouse. I would like to thank everyone who supported me along the way, especially, Bob Pickart, Carolina Nobre, Scott Hiller and Alex Quintero for putting up with my slow learning curve of both the CTD and the science, the US Coast Guard for providing support for important research, the MATE program for providing me with the opportunity and the science team (Tanja, Lauran, Liza, and Maria) and crew (Brian, Kevin, Mo, Gianna, V-dub, and Jeremy) for keeping me honest, helping me laugh at least once a day and appreciating the simple things.  A very special salute goes to the Coasties, who do such an amazing job operating the ship—I am in awe of their discipline and efficiency. Thank You.

Even though the Healy is a Coast Guard boat, its primary function is to provide technical and man support to Arctic scientific research. I was impressed, although not surprised, by the high number of projects that were benefitting from Healy cruise 1303. For example, from each CTD cast at least 8 different, however, related researchers were collecting important data. One of my favorite parts of the cruise were the science lectures that were given on sporadic nights throughout the trip. As someone who is just beginning a career in oceanographic research, this was an amazing opportunity to learn about different types of research that have important environmental implications.  The following are summaries of a few of the research projects aboard the boat.

Lecture 1—Breathing in: What we learn about life and death in the ocean from oxygen (Laurie Juranek—Oregon State University)

 Studying oxygen concentrations in the ocean allow researchers to track and better understand the biological and physical processes at play over a time frame as short as a few weeks to as long as several centuries.  In order to study these concentrations, Dr. Juranek establishes “water columns,” which are conceptual columns of water from surface to bottom sediments and are useful for evaluating the stratification of the thermal or chemical layers in the ocean.  Oxygen is present in these water columns as a result of both physical and biological processes; however, what primarily interests researchers is the oxygen in the water resulting from the biological process of photosynthesis because oxygen levels are indicators of phytoplankton (diatoms, coccolithophors, cyanobacteria, etc.) going through the photosynthesis and providing or becoming the bottom of the food chain and, by extension provide a picture of the overall productivity of the ecosystem. Surface water samples with high oxygen levels are an indication of higher productivity, while areas of low oxygen are an indication of low productivity.

In order to illustrate productivity in the water column, Juranek, uses known relationships between water temperature and the amount of dissolved oxygen and argon to determine the deviation of oxygen saturation from the expected equilibrium levels. The reason for looking at the relationship between oxygen and temperature is that the interactions are predictable as colder waters are able to hold higher amounts of gas. Argon is used as a comparison gas because it is an inert gas and, therefore, not impacted by biological processes, while it still acts in similar ways to oxygen in the water column. Surface water is collected during underway transport and then sampled using a mass-spectrometer to determine the weights of the gasses present in the water. Using the relationship between the argon and oxygen saturation levels, Juranek is able to determine if the direction of the oxygen flow is a result of biological or physical processes.

Based on the most recent data collected on the cruise, Juranek is finding that the highest rate of productivity is at the Chukchi shelf, while the lowest rate of productivity is in the Bering Strait, where the water is relatively unstable. These results are what she was expecting to observe; however, she is excited to continue to sample throughout the area.

Lecture 2—Nine North Slope Mooring Cruises: What have we Learned? Bob Pickart (Woods Hole Oceanographic Institute)

Prior to 2002, very little was known about the currents of the Arctic Ocean and what happens to the warm Pacific water and cool Atlantic water after entering the Bering Strait. Over the last ten years, Dr. Pickart has been gathering data about the water flow dynamics, particularly within the Pacific Water Boundary Current that runs between the northern Alaskan coast and the Beaufort Shelf and flows as far west as the Amundsen Gulf in Canada. Originally it was hypothesized that a majority of the water entering at the Bering Strait would follow the expected path along the northern coast of Alaska. However, the collected data reveals that the PWBC is “leaky,” with less than 20% of the water making it into the current. Even more striking is that this percentage has been decreasing over the last few years, while the amount of water entering the Bering Strait has increased. Based on the data, Pickart believes that the water is lost as a result of two pathways, eddies and storms.

Pickart uses both moorings, which provide continuous data collection for as long as the battery lasts (about a year), and CTD transect lines, which provide a snap-shot of the water column.  Using the moorings, which are deployed and collected yearly, Pickart has gained a much better understanding of the impacts of storms on the PWBC, but hopes to further this knowledge, particularly with respect to the impacts of the increasing shifts in wind patterns and the resulting current changes, with data collected over the last several years as well as this voyage. Traditionally, the current flows east with the “warm” Pacific water on top of the “cooler” Atlantic water. In opposition to this current, the winds blow from the east. Typically, these winds have little to no effect on the current direction; however, during major storm events that result from the Beaufort High and Aleutian Low, the increasing wind speeds have a current altering effect. Pickart has discovered that it only takes wind speeds greater than 4m/s to result in a reversal of these currents.  Not only does the current completely change directions and flow to the west, but also the cooler Atlantic water pushes to the top, resulting in what is known as an upwelling event. Additionally, the warmer waters are pushed north into the ice regions, resulting in dramatic ice melting events. Following a storm, the winds subside and the current returns to its natural state. As the climate is changing, the winds in the Arctic have become more intense, especially during the summer and winter months leading to more upwelling and ice melting events, even during non-storm periods.

To further understand the current patterns of the Atlantic and Pacific waters, data collected through CTD casts are conducted on transect lines along important oceanographic features within the PWBC that include Barrow Canyon and Hanna Shoal. The CTD casts create full profiles of the water column and enable Pickart to use the abiotic features (mainly temperature and salinity) of the water to determine the origin of the water.  Using this data, he can create maps of the water flow patterns throughout the western portion of the Sea.

Lecture 3—Ocean Acoustics, More than Just Whales (Bruce Thayre—SCRIPPS Institute of Oceanography)

Thayre is using acoustic information collected from moorings to determine the anthropogenic impacts of sound on aquatic environments in the Arctic region. Instrumentation converts sound waves into a frequency, which is then used to make a spectrogram of the sound wave as it passes a fixed point. Using these graphs, Thayre identifies the different types of sounds occurring at all times. As it turns out, the Arctic Ocean is a very noisy place, filled with sounds resulting from biological, environmental and anthropogenic sources. Some of the loudest sounds in the ocean are marine mammals, rain, the movement of ice and seismic testing. Thayre is most interested in the sounds resulting from the air guns used for seismic surveys for oil and gas development. These air gun shots can be heard from over 100km away. Understanding the impacts of these sounds is important because they are most frequent during the months of September and October, which is also peak whaling season, so there is concern from local whalers that these tests are disrupting the yearly hunt.

Lecture 4—What can we Learn from Ice Algae in the Arctic (Tanja Schollmeier; University Alaska Fairbanks)

In order to gain an understanding of the impacts of changing climate on the Arctic benthic community, Schollmeier is using fatty acid and ice biomarkers to follow the food web. Within the Arctic ecosystem there are two different types of algae, ice algae and open ocean algae. Each year ice melts and reforms; with the reformation, there is an associated ice algal bloom. As a result of the seasonal timing, these ice algae rely heavily on C₁₃ for growth (while open ocean algae rely on C₁₂). Using fatty acids, this C₁₃ can then be traced up through the food chain in organisms from diatoms to benthic filter feeders such as clams, mussels and crabs. In areas where there has been higher ice coverage, there is typically a higher concentration of C₁₃ fatty acids in the benthic community. Additionally, Schollmeier uses the ice biomarker IP₂₅, which is a highly branched isoprenoid as it is only produced by algae that lives under the ice where light can shine through. As this is a relatively new strategy for tracing the consumption of ice algae, Schollmeier plans to quantify IP₂₅ in samples collected in the water column, sediment and benthos. The ultimate goal of her project is to use fatty acid and IP₂₅ analysis to determine if there are patterns of quantity along ice cover and, if so, to determine whether some organisms or specific feeding types show different patterns of algae consumption.