White Ice Research Articles

Reading Tiffany Chin: The Birth of the Oriental Female Skater on White Ice

Tiffany Chin’s emergence in figure skating, and the ways in which she was depicted by the media, can be understood as the birth of the oriental female skater on White ice. Figure skating has historically been viewed as a White sport, so Chin’s success in that space created an opportunity for future Asian American skaters. To that end, the media’s coverage of Chin offers insight into how the ‘differences’ of Asian American female skaters were initially registered, constructed, and communicated in a racialized and gendered way. This claim is supported through an understanding of how the background and history of American women’s figure skating, the sport’s traditional alignment with Whiteness, and a critical reading the media narratives surrounding Chin, combine to represent an American view that framed this Chin’s successes as the birth of the oriental female skater.

Ice cover and thermal regime in a dimictic seepage lake under climate change

ABSTRACTChanges in water temperature and ice cover are important for controlling the biogeochemical and food-web processes of dimictic lakes in temperate regions. To investigate these changes, we applied a 1-dimensional hydrodynamic lake-ice model to Crystal Lake, a 20 m deep, dimictic seepage lake in northern Wisconsin, USA, to a period of 23 years (1989–2011). The model, DYRESM-WQ-I, incorporates the evolution of blue ice, white ice, and snow cover; time-varying ice and snow albedo; and 2-way coupling across the ice–water interface by incorporating components of previous ice models embedded in the hydrodynamic component of the DYRESM-WQ model. A new element of the current model is time-varying sediment heat fluxes, important to under-ice water temperatures in shallow lakes. Simulations closely reproduce the observed annual stratification regime and ice phenology with standard errors in temperature of 0.7 °C; total difference of 10–20% in ice thickness compared with measured values; and standard errors of 0.9 d for ice-on and 1.55 d for ice-off. Under a likely future climate scenario involving changes in air temperature forecasted to occur by the middle of this century (2055), results suggest an average reduction in mean ice cover thickness of about 0.18 m and an increase in surface mixed-layer temperature of up to 3.5 °C over summer. In addition, water levels decreased by 5.1 m over the simulation period, mostly in response to greater evaporation from higher surface water temperature in summer. The results have important implications for seepage lakes in temperate regions, where projected changes in precipitation with climate warming will not compensate for increased evaporation from the lake surface and the likely alteration in groundwater flows.

Albedo of a Small Ice-Covered Boreal Lake: Daily, Meso-Scale and Interannual Variability on the Background of Regional Climate

In winter, the reflective properties of ice-and-snow-covered lakes and the surrounding surface covered with snow differ little. Estimation of the albedo becomes especially important in spring when the reflectivity of the ice-covered lakes differs markedly from the surrounding snow-free surface. The measurements of the snow and ice albedo in situ are necessary to ensure adequate analysis of remote sensing data and monitoring of the state of the land ice. A wide range of surface albedo of small boreal ice-covered Lake Vendyurskoe (North-Western Russia) is calculated from observational data of solar radiation obtained in 1995–2000 and 2002–2017. A noticeable variability of albedo due to spring melting and changes in weather conditions is described. Climatic variability (North Atlantic Oscillation (NAO) index, the average monthly air temperature and sum of precipitation in December-March) is analyzed in the context of possible influence on the maximal thickness of snow and white ice, and, consequently, on the spring lake albedo dynamics. In current work to estimate the external heat flux that comes from the atmosphere to the surface of the lake and presumably determines the dynamics of albedo during spring melting, a simple parameter was used: the accumulated sum of positive temperatures, starting from March 1. The obtained prognostic equation of the cubic dependence of albedo on the named parameter demonstrates a different rate of albedo decrease in the melting of snow, white, and congelation ice.

Reflective properties of white sea ice and snow

Abstract. White ice (ice with a highly scattering granular layer on top of its surface) and snow-covered ice occupy a large part of the sea ice area in the Arctic, the former in summer, the latter in the cold period. The inherent optical properties (IOPs) and the reflectance of these types of ice are considered from the point of view of the light scattering and radiative transfer theories. The IOPs – the extinction and absorption coefficients and the scattering phase function – are derived with the assumption that both the snow cover and the scattering layer of white ice are random mixtures of air and ice with the characteristic grain size significantly larger than the wavelength of incident light. Simple analytical formulas are put forward to calculate the bidirectional reflectance factor (BRF), albedo at direct incidence (the directional–hemispherical reflectance), and albedo at diffuse incidence (the bihemispherical reflectance). The optical model developed is verified with the data of the in situ measurements made during the R/V Polarstern expedition ARK-XXVII/3 in 2012.

Effect of the look-up line on the gaze and head orientation of elite ice hockey players

A “look-up line” (LUL) has been proposed for ice hockey, which is an orange 1 m (40′) warning line (WL) painted on the ice at the base of the boards. The LUL purports to provide an early warning to players to keep their head up prior to and as they are being checked. We determined if players looked up more on a rink with the LUL compared to a traditional Control rink. Elite offensive (O) and defensive (D) players competed 1 vs. 1, while wearing an eye tracker that recorded their quiet eye (QE) and fixation and tracking (F-T) and an electrogoniometer that measured head angle. External cameras recorded skate duration during four skate phases: P1 preparation, P2 decision-making, P3 cut to boards, P4 contact. The QE was the final fixation prior to contact between O and D as they skated towards and across the WL during P3 and P4. Skate phase durations (%) did not differ by rink or rink by position. More QE and F-T occurred on the WL on the LUL rink than on the Control. The expected increase in head angle on the LUL rink did not occur during P3 or P4. Post-hoc results also showed O and D skated further from the boards on the LUL rink, suggesting the players preferred to control the puck on white ice, rather than the orange colour of the LUL rink. More research is needed to determine if these results apply to the competitive setting.

Glacier naled evolution and relation to the subglacial drainage system based on water chemistry and GPR surveys (Werenskioldbreen, SW Svalbard)

ABSTRACTGlacier naledi are extrusive ice masses that appear in front of glaciers as a consequence of refreezing of meltwater seepage during the accumulation season. These structures provide a unique opportunity to understand subglacial drainage activity during the accumulation season; however, only few detailed studies have previously focused on their characteristics. Here, we investigated glacier-derived naled assemblages in the proglacial zone of the polythermal glacier Werenskioldbreen (27.4 km2) in SW Svalbard. We determined the spatial distribution of naledi using ground penetrating radar surveys. The main subglacial drainage pattern was related to a channel under the medial moraine, and three sources are linked to a distributed subglacial drainage network. The relation between atmospherically-corrected (Ca2+ + Mg2+) and (SO42−) in sub-naled waters was closely related to sulphide oxidation coupled with carbonate dissolution (r = 0.99; slope = 1.6). This is consistent with the local lithology, which is dominated by schist containing carbonates. We also found high carbonate saturation indices in pale white ice layers within the naled. We conclude that sulphide oxidation coupled with carbonate dissolution is the dominant chemical weathering process in the subglacial drainage system of Werenskioldbreen during the accumulation season.

Algorithm to retrieve the melt pond fraction and the spectral albedo of Arctic summer ice from satellite optical data

A new algorithm to retrieve characteristics (albedo and melt pond fraction) of summer ice in the Arctic from optical satellite data is described. In contrast to other algorithms this algorithm does not use a priori values of the spectral albedo of the sea-ice constituents (such as melt ponds, white ice etc.). Instead, it is based on an analytical solution for the reflection from sea ice surface. The algorithm includes the correction of the sought-for ice and ponds characteristics with the iterative procedure based on the Newton–Raphson method. Also, it accounts for the bi-directional reflection from the ice/snow surface, which is particularly important for Arctic regions where the sun is low. The algorithm includes an original procedure for the atmospheric correction, as well. This algorithm is implemented as computer code called Melt Pond Detector (MPD). The input to the current version of the MPD algorithm is the MERIS Level 1B data, including the radiance coefficients at ten wavelengths and the solar and observation angles (zenith and azimuth). Also, specific parameters describing surface and atmospheric state can be set in a configuration input file. The software output is the map of the melt ponds area fraction and the spectral albedo of sea-ice in HDF5 format. The numerical verification shows that the MPD algorithm provides more accurate results for the light ponds than for the dark ones. The spectral albedo is retrieved with high accuracy for any type of ice and ponds.

One-dimensional simulation of lake and ice dynamics during winter

An ice formation model, based on the solution of the heat conduction equation across blue ice, white ice and snow cover, is integrated into the Dynamic Reservoir Simulation Model (DYRESM) to allow for one-dimensional (vertical) winter simulation of lake dynamics during periods of ice cover. This is an extension of a previous three-layer snow and ice model to include two-way coupling between the ice and the water column. The process-based ice formation is suitable for application to mid-latitude regions and includes: snowmelt due to rain; formation of white ice; and variability in snow density, snow conductivity, and ice and snow albedo. The model was validated against published observations from Harmon lake, British Columbia, and new observations from Eagle lake, Ontario. The ice thickness and water column temperature profile beneath the ice were predicted with Root Mean Square Deviations (RMSD) of 1 cm and 0.38°C, respectively, during the winter of 1990-91in Harmon lake. In Eagle lake the 2011-12 year-round water column temperature profile was predicted with an RMSD of 1.8°C. Improved prediction of under-ice lake temperature, relative to published results from simpler models, demonstrates the need for models that accurately capture ice-formation processes, including ice to water column coupling, formation of both blue and white ice layers, and process-based ice and snow parameters (density, conductivity and albedo).

Effects of bubbles, cracks, and volcanic tephra on the spectral albedo of bare ice near the Transantarctic Mountains: Implications for sea glaciers on Snowball Earth

Spectral albedo was measured along a 6 km transect near the Allan Hills in East Antarctica. The transect traversed the sequence from new snow through old snow, firn, and white ice, to blue ice, showing a systematic progression of decreasing albedo at all wavelengths, as well as decreasing specific surface area (SSA) and increasing density. Broadband albedos under clear‐sky range from 0.80 for snow to 0.57 for blue ice, and from 0.87 to 0.65 under cloud. Both air bubbles and cracks scatter sunlight; their contributions to SSA were determined by microcomputed tomography on core samples of the ice. Although albedo is governed primarily by the SSA (and secondarily by the shape) of bubbles or snow grains, albedo also correlates highly with porosity, which, as a proxy variable, would be easier for ice sheet models to predict than bubble sizes. Albedo parameterizations are therefore developed as a function of density for three broad wavelength bands commonly used in general circulation models: visible, near‐infrared, and total solar. Relevance to Snowball Earth events derives from the likelihood that sublimation of equatorward‐flowing sea glaciers during those events progressively exposed the same sequence of surface materials that we measured at Allan Hills, with our short 6 km transect representing a transect across many degrees of latitude on the Snowball ocean. At the equator of Snowball Earth, climate models predict thick ice, or thin ice, or open water, depending largely on their albedo parameterizations; our measured albedos appear to be within the range that favors ice hundreds of meters thick.

Variability of light transmission through Arctic land-fast sea ice during spring

Abstract. The amount of solar radiation transmitted through Arctic sea ice is determined by the thickness and physical properties of snow and sea ice. Light transmittance is highly variable in space and time since thickness and physical properties of snow and sea ice are highly heterogeneous on variable time and length scales. We present field measurements of under-ice irradiance along transects under undeformed land-fast sea ice at Barrow, Alaska (March, May, and June 2010). The measurements were performed with a spectral radiometer mounted on a floating under-ice sled. The objective was to quantify the spatial variability of light transmittance through snow and sea ice, and to compare this variability along its seasonal evolution. Along with optical measurements, snow depth, sea ice thickness, and freeboard were recorded, and ice cores were analyzed for chlorophyll a and particulate matter. Our results show that snow cover variability prior to onset of snow melt causes as much relative spatial variability of light transmittance as the contrast of ponded and white ice during summer. Both before and after melt onset, measured transmittances fell in a range from one third to three times the mean value. In addition, we found a twentyfold increase of light transmittance as a result of partial snowmelt, showing the seasonal evolution of transmittance through sea ice far exceeds the spatial variability. However, prior melt onset, light transmittance was time invariant and differences in under-ice irradiance were directly related to the spatial variability of the snow cover.

Optical properties of the ice cover on Vendyurskoe lake, Russian Karelia (1995–2012)

AbstractSolar radiation penetrating the ice is one of the most important factors that determine the functioning of lake ecosystem in late winter. Parameterization of the attenuation of solar radiation in the snow-ice sheet is an essential tool in the study of the light regime of ice-covered lakes. The optical properties of the snow-ice sheet in Vendyurskoe lake, northwestern Russia, are investigated on the basis of long-term field observations (1995–2012). The four-layer approach (snow, white ice, slush and congelation ice) is used to study the attenuation of the downwelling planar irradiance in the snow-ice sheet. The bulk attenuation coefficients for four layers (18.8 m–1 for snow, 6 m−1 for white ice, 3.5 m−1 for slush and 2.1 m−1 for congelation ice) are calculated by the quasi-Newton method. A comparison of observed and calculated values of the irradiance beneath the ice shows that the determined coefficients adequately describe the attenuation of the downwelling irradiance by snow-ice cover.

Fuzzy-Logic Modeling of a Rolling Unmanned Vehicle in Antarctica Wind Shear

of wind shear are investigated using the recorded test data during a flight from the Pegasus white ice runway in Antarctica. The main purpose of this paper is to determine the reasons and characteristics of roll oscillations for improvement of autopilot design and ground operator training. The Meridian flight test is conducted with the necessaryrangeconstraint, which precludes steadylevel flight.The measured orestimated data,such as theangle of attack and sideslip angle, are filtered through a nonlinear compatibility analysis. The estimated aerodynamic coefficients are modeled as implicit functions of filtered flight variables in a concept of aerodynamic model identification, instead of parameter identification. A model identification method called fuzzy-logic modeling is used to set up the aerodynamic models without assuming the functional relations. The aircraft’s oscillatory stability and control derivatives are found to be significantly impacted by the environmental disturbances. The exhibited highly oscillatory motion in the manual-control mode is analyzed and identified as the pilot-induced oscillation with a new energy method. It is shown that the pilot-induced oscillation is identified as the motion when the motion energy is increasedbythecontrolinput.Intheautopilot flight,themotionisdeterminedtobewingrock,whichisexcitedbythe pilot-induced oscillation in the manual mode and sustained by the interaction between the wing wake and the V tail.

Spectral features analysis of sea ice in the Arctic Ocean

Sea ice in the Arctic Ocean plays an important role in the global climate change, and its quick change and impact are the scientists' focus all over the world. The spectra of different kinds of sea ice were measured with portable ASD FieldSpec 3 spectrometer during the long-term ice station of the 4th Chinese national Arctic Expedition in 2010, and the spectral features were analyzed systematically. The results indicated that the reflectance of sea ice covered by snow is the highest one, naked sea ice the second, and melted sea ice the lowest. Peak and valley characteristics of spectrum curves of sea ice covered by thick snow, thin snow, wet snow and snow crystal are very significant, and the reflectance basically decreases with the wavelength increasing. The rules of reflectance change with wavelength of natural sea ice, white ice and blue ice are basically same, the reflectance of them is medium, and that of grey ice is far lower than natural sea ice, white ice and blue ice. It is very significant for scientific research to analyze the spectral features of sea ice in the Arctic Ocean and to implement the quantitative remote sensing of sea ice, and to further analyze its response to the global warming.

Bath Salts: The Ivory Wave of Trouble

Mephedrone and MDPV are both β-ketophenethylamine derivatives of cathinone, a compound isolated from the East African plant Catha edulis (khat, qat). Mephedrone is commonly referred to as plant food, MCAT, 4-MMC, meow meow, meph, and drone; MDPV is commonly called MTV, MDPK, Magic, and Super Coke. Both are structurally similar to amphetamines, with mephedrone sharing close similarities with methamphetamine and MDPV with ecstasy (3,4-methylenedioxymethamphetamine; MDMA). Bath salts pose an increasing public health risk in the United States, with reports of toxicity and mortality increasing along with calls to poison centers throughout the United States. Packages labeled with innocuous monikers such as White Ice, Ivory Wave, Ocean Snow, Lunar Wave, and Vanilla Sky intentionally belie the dangerous substances within, which are by no means intended to replace legitimate bath products. The white or tan crystalline powder commonly is administered by nasal insufflation or oral ingestion; however, rectal suppository and less commonly, intramuscular or intravenous injection, are also reported.1,2 A movement to ban these substances is growing in the United States, following similar actions in Europe.3 Although successfully outlawed in some locales, this movement has not eliminated the public health hazards posed by mephedrone or MDPV. Emergency physicians (EP) should thus be knowledgeable in the epidemiology of bath salt abuse, the clinical toxidrome with which bath salt toxicity presents, and appropriate treatment strategies to reduce morbidity and mortality in patients presenting with bath salt toxicity.

Three‐dimensional simulation of lake and ice dynamics during winter

An ice‐formation algorithm is implemented in the three‐dimensional Estuary and Lake Computer Model, to allow simulation of hydrodynamics and the thermal structure beneath the ice during winter. The one‐dimensional governing equation of heat conduction among the three layers of white ice, blue ice, and snow is solved for the formation of ice cover considering the heat flux through air and water. This algorithm is applied independently in each grid cell within the simulation domain, allowing for spatially variable ice formation. The model was validated against observed data from both a large and a small Canadian mid‐latitude lake (Lake Ontario and Harmon Lake, respectively). The lake surface temperature and the distribution and thickness of ice cover on Lake Ontario were predicted successfully during the 2006–2007 winter period. The model also accurately simulated spring 2007 temperature profiles, as typically used for the initial conditions for a summer simulation. The variation of ice and snow thickness, and vertical temperature profiles, were well‐simulated for Harmon Lake during winter 1990–1991. These comparisons demonstrate the applicability of the model for year‐round simulation of mid‐latitude lakes of varying size.

Impact of horizontal spreading on light propagation in melt pond covered seasonal sea ice in the Canadian Arctic

[1] Melt pond covered sea ice is a ubiquitous feature of the summertime Arctic Ocean when meltwater collects in lower-lying areas of ice surfaces. Horizontal transects were conducted during June 2008 above and below landfast sea ice with melt ponds to characterize surface and bottom topography together with variations in transmitted spectral irradiance. We captured a rapid progression from a highly flooded sea ice surface with lateral drainage toward flaws and seal breathing holes to the formation of distinct melt ponds with steep edges. As the mass of the ice cover decreased due to meltwater drainage and rose upward with respect to the seawater level, the high-scattering properties of ice above the water level (i.e., white ice) were continuously regenerated, while pond waters remained transparent compared to underlying ice. The relatively stable albedos observed throughout the study, even as ice thickness decreased, were directly related to these surface processes. Transmission through the ice cover of incident irradiance in the 400–700 nm wave band ranged from 38% to 67% and from 5% to 16% beneath ponded and white ice, respectively. Our results show that this transmission varied not only as a function of surface type (melt ponds or white ice) areal coverage but also in relation to ice thickness and proximity to other surface types through the influence of horizontal spreading of light. Thus, in contrast to albedo, this implies that regional transmittance estimates need to consider melt pond size and shape distributions and variations in optical properties and thickness of the ice cover.

Characteristics of two distinct high-light acclimated algal communities during advanced stages of sea ice melt

Biological characteristics of ice-associated algal communities were studied in Darnley Bay (western Canadian Arctic) during a 2-week period in July 2008 when the landfast ice cover had reached an advanced stage of melt. We found two distinct and separate algal communities: (1) an interior ice community confined to brine channel networks beneath white ice covers; and (2) an ice melt water community in the brackish waters of both surface melt ponds and the layer immediately below the ice cover. Both communities reached maximum chlorophyll a concentrations of about 2.5 mg m−3, but with diatoms dominating the interior ice while flagellates dominated the melt water community. The microflora of each community was diverse, containing both unique and shared algal species, the latter suggesting an initial seeding of the ice melt water by the bottom ice community. Absorption characteristics of the algae indicated the presence of mycosporine-like amino acids (MAAs) and carotenoid pigments as a photoprotective strategy against being confined to high-light near-surface layers. Although likely not contributing substantially to total annual primary production, these ice-associated communities may play an important ecological role in the Arctic marine ecosystem, supplying an accessible and stable food source to higher trophic levels during the period of ice melt.

Summertime boundary layer winds over the Darwin–Hatherton glacial system, Antarctica: observed features and numerical analysis

AbstractThree temporary Automatic Weather Stations measured summertime surface layer climate over the Darwin–Hatherton Glacial system. These data were used to test a Polar optimized Weather Research and Forecasting model (Polar-WRF) simulation for December as a case study. Observations show differences in hourly averaged solar and net all-wave radiation between white ice and blue ice areas (BIAs). Although the down-welling solar radiation is higher over the white ice region, the net all-wave energy is higher over the BIA. Derived albedo for each surface type confirms that the blue ice areas have lower albedo. Also, the hourly averaged temperatures are higher at lower elevation stations, creating a gradient towards the Ross Ice Shelf. Analysis shows that there is a diurnal oscillation in strength and intensity of the katabatic wind. The two lower stations register a distinct reversal of wind direction in the early afternoon due to intrusion of an anabatic circulation. Anabatic winds are not prevalent further up the Darwin Glacier. A high-resolution Polar-WRF simulation as a case study shows good agreement with observations. The December 2008 case study is characterized by a strong south-westerly katabatic wind over Hatherton, whereas the flow over Lower Darwin was diurnally reversing. Polar-WRF shows that the katabatic front advanced and retreated periodically between Hatherton and Lower Darwin.

Community Monitoring of Environmental Change: College-Based Limnological Studies at Crazy Lake (Tasirluk), Nunavut

In light of the difficult logistics and high cost of polar research into climate change, involvement of local people can contribute immensely to important data collection. One can use the knowledge and skills of human resources that are already present—teachers, students, and community members. An example is the long-term Arctic monitoring program established at Crazy Lake (63°51' N, 68°28' W) near Iqaluit, Nunavut, to monitor snow and ice thickness, biological components, and water chemistry. Nunavut Arctic College students collected basic limnological data at Crazy Lake during spring field camps held between 10 and 16 April in 2005 and 2006. Mean snow depth ± SD for Crazy Lake was 0.46 ± 0.13 m (n = 24). White ice averaged 0.13 ± 0.12 m and black ice 1.38 ± 0.28 m. Total ice thickness (white ice + black ice) ranged between 0.91 and 1.91 m (mean = 1.51 ± 0.22 m). The total lake cover (snow + ice) averaged 1.97 ± 0.20 m. Water depth ranged from 1.48 to 18.58 m (mean = 10.10 ± 4.99 m).

Using remote sensing to estimate sea ice thickness in the Bohai Sea, China based on ice type

It is challenging to use traditional remote sensing techniques to accurately determine the extent and thickness of ice in the Bohai Sea, on account of the presence of sea impurities (i.e. mud, salt bubbles and sand) and shape irregularities. Accordingly, we performed a series of reflectance spectra experiments to empirically link remote measurements of surface reflectance with in situ sea ice thickness measurements in the Bohai Sea. Two years of Thematic Mapper (TM) band 2 and Moderate Resolution Imaging Spectroradiometer (MODIS) band 4 data were used to distinguish between the following sea ice types, using spectral reflectance thresholds of 6.4, 9.6, 10.3 and 12.1%: (a) clean nilas ice (a thin elastic crust of ice up to 10 cm thick that, under pressure, may deform by finger rafting; (b) nilas ice and pancake ice (roughly circular accumulations of frazil ice, usually less than about 3 m in diameter, with raised rims caused by collisions); (c) grey and grey–white ice; and (d) cumulative ice (<30 cm). By establishing a relationship between sea ice type and ice thickness, a novel, practical and low-cost remote sensing technique is introduced to estimate the extent and distribution of sea ice thickness over a large spatial scale. The results obtained by remote sensing are validated with in situ ice shape measurements. The MODIS and TM data are used to distinguish between three ice thickness grades (6–9, 10–20 and 20–30 cm).