This report presents moored observations of velocity, temperature, and conductivity
made at the "0" Camp during CEAREX (Coordinated Eastern Arctic Experiment).
The measurements were made in the Arctic Ocean, near 83 ON and 5 ° to 11 °E, from
sensors suspended below the ice during March-April 1989.
We designed an experiment to see if turbulence induced by shear instability
could be a mechanism. Using equipment readily available we completed
an experiment from the Ice Island T-3. A sensor array of current meters
and thermistors (described later on) was suspended beneath the sea ice of
Colby Bay, T-3,...
This report documents observations of temperature and salinity made in the Arctic Ocean during the 1995 cruise of the submarine USS Cavalla. This cruise was the second civilian scientific cruise to the Arctic Ocean aboard a U.S. Navy Sturgeon-class submarine, and the first of five annual SCICEX cruises.
The SCICEX-95...
Upper ocean hydrography in the central Arctic Ocean
has relaxed since 2000 to near-climatological conditions
that pertained before the dramatic changes of the 1990s. The
behavior of the anomalies of temperature and salinity in the
central Arctic Ocean follow a first-order linear response to
the AO with time constant of...
This report presents time series measurements of velocity, temperature and conductivity made during the Lead Experiment (LEADEX). These observations were made in the Beaufort Sea, Arctic Ocean, in the vicinity of 73°N, 144°W, during March-April 1992. Month-long observations at the base camp were made between the surface and 400 m...
We present a survey of Nd isotopes measured from authigenic phases on surface sediments from the Arctic Ocean seafloor. Comparison with published dissolved water column Nd isotope distributions suggests that epsilon Nd from sediment leachates accurately represents bottom water circulation of the Arctic Ocean, with Atlantic (similar to 11 epsilon...
Central to an understanding of evolution in sea-ice characteristics in response to climate change is an understanding of sea-ice dynamics. In this study, we investigate regional differences in ice dynamics in the Beaufort Sea and High Arctic using high-frequency ice buoy (beacon) data deployed during the SEDNA and IPY-CFL field...
Dissolved barium (Ba) was measured along transects across Fram and Denmark Straits as part of the 1998 ARK-XIV/2 Polarstern expedition. Results are combined with other available tracer observations to analyze water mass composition at Fram Strait. A combination of Pacific water and Eurasian river runoff dominated (>80% and >10% of...
A coupled biophysical model is used to examine the impact of the great Arctic cyclone
of early August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic
Ocean (PSA). Model results indicate that the cyclone influences the marine planktonic
ecosystem by enhancing productivity on the shelves...
A thermistor chain was moored below the pack ice from 50–150 m in the Arctic Ocean for five days in 1981. Oscillations in temperature are attributed to the vertical dispalcement of internal waves. The spectral shape of isotherm dispalcement is consistent with the Garrett-Munk model and other internal wave observations,...
The Arctic Ocean is an important link in the global hydrological cycle, storing freshwater and releasing it to the North Atlantic Ocean in a variable fashion as pack ice and freshened seawater. An unknown fraction of this return flow passes through Nares Strait between northern Canada and Greenland. Surveys of...
During summer 2007, perennial sea ice in the Beaufort Sea, Arctic Ocean, experienced an unprecedented amount of basal melt. It has previously been shown that this basal melt was linked to an increase in open-water fraction, increasing absorption of solar radiation into the ocean. GPS ice drifters, deployed around the...
The energy levels of internal waves observed during the
Arctic Internal Wave Experiment (AIWEX), conducted from the
drifting pack ice in the Beaufort Sea, increased as the speed of
the ice drift increased. The possibility of these waves being
generated by moving pack ice with a corrugated under-side is
explored...
Water samples from the Arctic Ocean were analyzed in order to assess the present nature of particulate organic matter and investigate the effect of climate-driven changes on the ecology of the region. 661 individual surface water samples and 216 samples from CTD casts were collected from the Bering, Chukchi, and...
One of the challenges in oceanography is to understand the influence of environmental factors on the abundances of prokaryotes and viruses. Generally, conventional statistical methods resolve trends well, but more complex relationships are difficult to explore. In such cases, Artificial Neural Networks (ANNs) offer an alternative way for data analysis....
This research questions the effectiveness of newspapers as a
vehicle of environmental information by determining whether the
public attitude in Alaska towards off-shore oil exploration was
consistent with that expressed in the local newspapers. All
newspaper articles about off-shore oil exploration published in
Alaska between 1980 and May 1987 were...
We investigated 32 net primary productivity (NPP) models by assessing skills to reproduce integrated NPP in the Arctic Ocean. The models were provided with two sources each of surface chlorophyll-a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed-layer depth (MLD). The models were most sensitive to...
The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. Recent research indicates that there has been a warming trend in ocean temperatures over the last...
The Coordinated Eastern Arctic Experiment (CEAREX) was a multi-platform geophysical study covering the period from winter 1988 to spring 1989 in the vicinity of the Yermak Plateau and Fram Strait. The Oceanography ("0") Camp component of CEAREX was designed to study the physical oceanographic conditions from the deep Nansen Basin...
Here we report results from an extensive survey of
dissolved organic carbon (DOC) in the Arctic Ocean, which
was achieved by means of a high-resolution, in situ UV fluorometer
deployed on a nuclear submarine. Based on a strong
linear correlation observed between fluorescence (320 nm excitation,
420 nm emission) and...
A major achievement in research supported by the Kluane Lake Research Station was the recovery, in 2001–02, of a suite of cores from the icefields of the central St. Elias Mountains, Yukon, by teams of researchers from Canada, the United States, and Japan. This project led to the development of...
This thesis investigates lithogenic sediments on the Siberian Arctic shelf, their sources, modes of dispersal, transport pathways and post-depositional diagenetic alteration. Working with cores collected from the Chukchi, East Siberian and Laptev Seas, we characterize surface-sediment elemental chemistry and clay mineralogy. We identify five regions with endmember sedimentary compositions. Comparing...
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LIST OF FIGURES
Figure Pag
2.1 a) ArcticOcean and marginal seas. b) Siberian-shelf surface
The carbon system of the western Arctic Ocean is undergoing a rapid transition as sea ice extent and thickness decline. These processes are dynamically forcing the region, with unknown consequences for CO2 fluxes and carbonate mineral saturation states, particularly in the coastal regions where sensitive ecosystems are already under threat...
Autonomous buoys were deployed in 2011 in the central Arctic: An Ice-Tethered Profiler (ITP) and Ice Mass Balance (IMB) buoys were deployed in the Makarov basin; a Polar Ocean Profiling System (POPS) and Ice Thickness (Ice-T) buoy were deployed on the Eurasian Basin. The two different sites were approximately 70km...
Dramatic and ongoing changes pervading the Arctic and subarctic seas over
recent decades have motivated this effort to track and better understand hydrographic
variability using chemical tracers. Particular emphasis has been paid to differentiating
freshwater contributions to upper layers: namely Pacific water, meteoric water, and
sea-ice melt/formation.
Data collected in...
Ocean Wave Energy Converters (OWECs) operating on
the water surface are subject to storms and other extreme
events. In particular, high and steep waves, especially
breaking waves, are likely the most dangerous to OWECs. A
method for quantifying the breaking severity of waves is
presented and applied to wave data...
The albedo of Arctic sea ice depends greatly on the formation of melt ponds. These ponds form in depressions on the ice as surface snow melts during the summer months, and their location is determined mainly by the initial snow topography. Using a high resolution sea ice model forced with...
The thesis describes the properties of surface wind and air
temperature time series recorded at three locations on the pack ice
of the Beaufort Sea. Time series consisting of sequential one-half
hourly means were constructed for a period of approximately a year.
A diurnal fluctuation in air temperature is found...
Arctic soils are warming, making vast stores of organic carbon available for conversion to CO₂. This could create a positive feedback loop and accelerate global warming, but the processes that convert this carbon into CO₂ are not well understood. We investigated how the combined activities of sunlight and microbes degrade...
Microbial communities in Arctic coastal lagoons drive biogeochemical cycles at the terrestrial-marine interface and help to determine the fate and form of resources like nitrogen (N) and carbon (C) as they are delivered to the Arctic Ocean. Though rising rates of primary production in the Arctic Ocean are well-characterized, the...
The Arctic climate system is changing dramatically as a response to rising atmospheric greenhouse gas concentrations. Key indicators of Arctic change include thinning and retreating of Arctic pack ice, thawing permafrost, greening tundra, and rising surface temperatures. The structure of the atmospheric boundary layer influences and is influenced by processes...
The Pacific Arctic is undergoing rapid biogeochemical changes in response to warming air temperatures caused by climate forcing. This is manifesting as changes in seasonal sea ice thickness and sea ice extent, as well as changes in primary production within surface waters. The data and samples analyzed here were collected...
A multidisciplinary oceanographic research program was carried out by US and Canadian investigators in the spring of 1995 in the Canadian Arctic, near Lowther Island in Barrow Strait. The program, referred to here as Resolute 95 (or Res95), had a variety of objectives, including detailed examination of the mechanisms responsible...
Leads act as windows through which solar radiation enters the upper ocean. Studies of the heat budget and ice melt require accurate parameterization of the albedo. Results from summertime measurements of albedo over leads show that under cloudy conditions the average albedo is 0.066 with a standard deviation of 0.007....
Arctic sea ice concentration and volume have declined due to greenhouse gas radiative forcing and an overall positive climate feedback. At the same time, there have been noteworthy weather and climate circulation anomalies both within the Arctic and extending through the midlatitudes and even into the tropics, leading some studies...
Burial Lake sediments from the Noatak Basin in the northwest Brooks Range of Arctic Alaska (68.43°N, 159.17°W, 21.5 m water depth) provide the oldest continuous lacustrine record of paleo-environmental change and paleomagnetic secular variation (PSV) in eastern Beringia. A precise radiocarbon chronology, determined through accelerator mass spectrometry (AMS) allows us...
Patterns of primary productivity in the Arctic are expected to change with continued warming, yet productivity measurements are historically limited, both spatially and temporally. An established method of measuring net biological oxygen production, which can be used to estimate net community production (NCP) rates, is with an equilibrated inlet mass...
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1
1 Introduction
The ArcticOcean is changing at an unprecedented rate: the thirteen
The work described herein entailed three separate but related
education/outreach activities aimed at distinct audiences. This portfolio required
acquisition of a range of skills in order to effectively convey information in a fashion accessible to each target audience. The first project consists of contributions to a
sample chapter of a...
The spectral composition of internal gravity waves under the Arctic pack ice during the Arctic Internal Wave Experiment (AIWEX) was found to be strikingly different from observations at lower latitudes. Time series of vertical displacement were inferred from horizontal and vertical arrays of temperature and conductivity sensors. Frequency spectra indicate...
Distributions of temperature, salinity, and barium in near-surface waters (depth ≤ 50 m) of the Laptev Sea and adjacent areas of the Arctic Ocean are presented for the summers of 1993, 1995, and 1996. The tracer data indicate that while fluvial discharge was largely confined to the shelf region of...
Internal gravity waves measured under the Arctic pack ice were strikingly different from measurements
at lower latitudes. The total wave energy, integrated over the internal wave frequency band, was lower by
a factor of 0.03-0.07, and the spectral slope at high frequency was nearly -1 in contrast to the -2...
Hydrographic and velocity profiles were made through a small baroclinic cyclonic eddy during the Arctic Internal Wave Experiment in the Canada Basin in April 1985. The maximum measured azimuthal velocity was 0.38 m s⁻¹ at a depth of 115 m, with velocities decaying to near zero at 30 and 270...
Arctic cod (Boreogadus saida) is an ecologically significant species that plays a critical role channeling energy throughout the Arctic marine food web. Arctic cod is uniquely adapted to occupy ice edge habitats, however, a basic understanding of its larval physiology and habitat requirements is lacking due to widespread sea ice...
The exchange of carbon on earth is one of the fundamental processes that sustains life and regulates climate. Since the onset of the Industrial Revolution, the burning of fossil fuels and anthropogenic land conversion have altered the carbon cycle, increasing carbon dioxide in the atmosphere to levels that are unprecedented...
