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Background The Antarctic minke whale (Balaenoptera bonaerensis) is a relatively small baleen whale species and is well suited to life in the Antarctic pack ice. Information on their individual movement and distribution patterns is largely unknown due to their association with sea ice habitat where direct observations are limited. The primary objectives of this study are (1) to use satellite telemetry to quantify the movement patterns, distribution, and presumed foraging areas of Antarctic minke whales and (2) to assess the environmental conditions that are associated with areas used by minke whales along the western Antarctic Peninsula. Results Individual movement patterns from three Antarctic minke whales fitted with ARGOS-linked transmitters were analyzed with respect to environmental conditions. Behavioral states were identified using the Multi-Scale Straightness Index. Satellite telemetry revealed disparate behavioral patterns between these three individuals. Generalized additive model analysis demonstrated environmental variables, particularly sea ice, bathymetry, and sea surface temperature, are the best predictors of presumed foraging areas. Conclusions Satellite telemetry from three individuals revealed Antarctic minke whale summer foraging spaces are highly individualized but can generally be associated with pack ice habitat over the continental shelf. The coupled relationship between minke whales, krill, and sea ice suggests that these whales may be sensitive to changes in sea ice concentration, extent, and duration, making them particularly vulnerable to climate change.

This work evaluates two distinct calculations of central tendency for sea-ice thickness and quantifies the impact such calculations have on ice volume for the Southern Ocean. The first calculation, area-weighted average thickness, is computed from polygonal ice features and then upscaled to regions. The second calculation, integrated thickness, is a measure of the central value of thickness categories tracked across different scales and subsequently summed to chosen regions. Both methods yield the same result from one scale to the next, but subsequent scales develop diverging solutions when distributions are strongly non-Gaussian. Data for this evaluation are sea-ice stage-of-development records from US National Ice Center ice charts from 1995 to 1998, as proxy records of ice thickness. Results show regionally integrated thickness exceeds area-weighted average thickness by as much as 60% in summer with as few as five bins in thickness distribution. Year-round, the difference between the two calculations yields volume differences consistently >10%. The largest discrepancies arise due to bimodal distributions which are common in ice charts based on current subjective-analysis protocols. We recommend that integrated distribution be used for regional-scale sea-ice thickness and volume estimates from ice charts and encourage similar testing of other large-scale thickness data archives.

During late winter 2007, coincident measurements of sea ice were collected using various sensors at an ice camp in the Beaufort Sea, Canadian Arctic. Analysis of the archived data provides new insight into sea-ice isostasy and its related R-factor through case studies at three scales using different combinations of snow and ice thickness components. At the smallest scale (R-factor is allowed to vary: ranging from 2 to 12, with mean of 5.17, mode of 5.88 and skewed distribution. At regional scales, underwater, airborne and spaceborne platforms are always missing thickness variables from either above or below sea level. For such situations, realistic agreement is found by applying small-scale skewed ranges for the R-factor. These findings encourage a broader isostasy solution as a function of potential energy and length scale. Overall, results add insight to data collection strategies and metadata characteristics of different thickness products.

Childers, D.P.; Madsen, J.A.; Krantz, D.E., and Deliberty, T.L., 2019. Constraining the geometry of subsurface paleochannels beneath Delaware Bay and the Mid-Atlantic inner continental she...

Soil moisture is a critical component of the earth system and plays an integrative role among the various subfields of physical geography. This paper highlights not just how soil moisture affects atmospheric, geomorphic, hydrologic, and biologic processes but that it lies at the intersection of these areas of scientific inquiry. Soil moisture impacts earth surface processes in such a way that it creates an obvious synergistic relationship among the various subfields of physical geography. The dispersive and cohesive properties of soil moisture also make it an important variable in regional and microclimatic analyses, landscape denudation and change through weathering, runoff generation and partitioning, mass wasting, and sediment transport. Thus, this paper serves as a call to use research in soil moisture as an integrative and unifying theme in physical geography. © The Author(s) 2010.

[1] Ship-based observations are used to describe regional and seasonal changes in the thickness distribution and characteristics of sea ice and snow cover thickness around Antarctica. The data set comprises 23,373 observations collected over more than 2 decades of activity and has been compiled as part of the Scientific Committee on Antarctic Research (SCAR) Antarctic Sea Ice Processes and Climate (ASPeCt) program. The results show the seasonal progression of the ice thickness distribution for six regions around the continent together with statistics on the mean thickness, surface ridging, snow cover, and local variability for each region and season. A simple ridge model is used to calculate the total ice thickness from the observations of level ice and surface topography, to provide a best estimate of the total ice mass, including the ridged component. The long-term mean and standard deviation of total sea ice thickness (including ridges) is reported as 0.87 ± 0.91 m, which is 40% greater than the mean level ice thickness of 0.62 m. Analysis of the structure function along north/south and east/west transects revealed lag distances over which sea ice thickness decorrelates to be of the order of 100–300 km, which we use as a basis for presenting near-continuous maps of sea ice and snow cover thickness plotted on a 2.5 � 5.0 grid.