Articles | Volume 8, issue 4
08 Aug 2014
Research article | 08 Aug 2014
Temporal dynamics of ikaite in experimental sea ice
S. Rysgaard et al.
S. Rysgaard, D. H. Søgaard, M. Cooper, M. Pućko, K. Lennert, T. N. Papakyriakou, F. Wang, N. X. Geilfus, R. N. Glud, J. Ehn, D. F. McGinnis, K. Attard, J. Sievers, J. W. Deming, and D. Barber
The Cryosphere, 7, 707–718,
Zhiyuan Gao, Nicolas-Xavier Geilfus, Alfonso Saiz-Lopez, and Feiyue Wang
Atmos. Chem. Phys., 22, 1811–1824,Short summary
Every spring in the Arctic, a series of photochemical events occur over the ice-covered ocean, known as bromine explosion events, ozone depletion events, and mercury depletion events. Here we report the re-creation of these events at an outdoor sea ice facility in Winnipeg, Canada, far away from the Arctic. The success provides a new platform with new opportunities to uncover fundamental mechanisms of these Arctic springtime phenomena and how they may change in a changing climate.
Abigail Smith, Alexandra Jahn, Clara Burgard, and Dirk Notz
The Cryosphere Discuss.,
Revised manuscript under review for TCShort summary
The timing of Arctic sea ice melt each year is an important metric for assessing how sea ice in climate models compares to satellite observations. Here, we utilize a new tool for creating more direct comparisons between climate models projections and satellite observations of Arctic sea ice, such that the melt onset dates are defined the same way. This tool allows us to identify climate model biases more clearly and gain more information about what the satellites are observing.
Xiaoxu Shi, Dirk Notz, Jiping Liu, Hu Yang, and Gerrit Lohmann
Geosci. Model Dev., 14, 4891–4908,Short summary
The ice–ocean heat flux is one of the key elements controlling sea ice changes. It motivates our study, which aims to examine the responses of modeled climate to three ice–ocean heat flux parameterizations, including two old approaches that assume one-way heat transport and a new one describing a double-diffusive ice–ocean heat exchange. The results show pronounced differences in the modeled sea ice, ocean, and atmosphere states for the latter as compared to the former two parameterizations.
Max Thomas, James France, Odile Crabeck, Benjamin Hall, Verena Hof, Dirk Notz, Tokoloho Rampai, Leif Riemenschneider, Oliver John Tooth, Mathilde Tranter, and Jan Kaiser
Atmos. Meas. Tech., 14, 1833–1849,Short summary
We describe the Roland von Glasow Air-Sea-Ice Chamber, a laboratory facility for studying ocean–sea-ice–atmosphere interactions. We characterise the technical capabilities of our facility to help future users plan and perform experiments. We also characterise the sea ice grown in the facility, showing that the extinction of photosynthetically active radiation, the bulk salinity, and the growth rate of our artificial sea ice are within the range of natural values.
Stefan Kern, Thomas Lavergne, Dirk Notz, Leif Toudal Pedersen, and Rasmus Tonboe
The Cryosphere, 14, 2469–2493,Short summary
Arctic sea-ice concentration (SIC) estimates based on satellite passive microwave observations are highly inaccurate during summer melt. We compare 10 different SIC products with independent satellite data of true SIC and melt pond fraction (MPF). All products disagree with the true SIC. Regional and inter-product differences can be large and depend on the MPF. An inadequate treatment of melting snow and melt ponds in the products’ algorithms appears to be the main explanation for our findings.
Clara Burgard, Dirk Notz, Leif T. Pedersen, and Rasmus T. Tonboe
The Cryosphere, 14, 2369–2386,Short summary
The high disagreement between observations of Arctic sea ice makes it difficult to evaluate climate models with observations. We investigate the possibility of translating the model state into what a satellite could observe. We find that we do not need complex information about the vertical distribution of temperature and salinity inside the ice but instead are able to assume simplified distributions to reasonably translate the simulated sea ice into satellite
Clara Burgard, Dirk Notz, Leif T. Pedersen, and Rasmus T. Tonboe
The Cryosphere, 14, 2387–2407,Short summary
The high disagreement between observations of Arctic sea ice inhibits the evaluation of climate models with observations. We develop a tool that translates the simulated Arctic Ocean state into what a satellite could observe from space in the form of brightness temperatures, a measure for the radiation emitted by the surface. We find that the simulated brightness temperatures compare well with the observed brightness temperatures. This tool brings a new perspective for climate model evaluation.
Stefan Kern, Thomas Lavergne, Dirk Notz, Leif Toudal Pedersen, Rasmus Tage Tonboe, Roberto Saldo, and Atle MacDonald Sørensen
The Cryosphere, 13, 3261–3307,Short summary
A systematic evaluation of 10 global satellite data products of the polar sea-ice area is performed. Inter-product differences in evaluation results call for careful consideration of data product limitations when performing sea-ice area trend analyses and for further mitigation of the effects of sensor changes. We open a discussion about evaluation strategies for such data products near-0 % and near-100 % sea-ice concentration, e.g. with the aim to improve high-concentration evaluation accuracy.
Anne Sofie Lansø, Thomas Luke Smallman, Jesper Heile Christensen, Mathew Williams, Kim Pilegaard, Lise-Lotte Sørensen, and Camilla Geels
Biogeosciences, 16, 1505–1524,Short summary
Although coastal regions only amount to 7 % of the global oceans, their contribution to the global oceanic surface exchange of CO2 is much greater. In this study, we gain detailed insight into how these coastal marine fluxes compare to CO2 exchange from coastal land regions. Annually, the coastal marine exchanges are smaller than the total uptake of CO2 from the land surfaces within the study area but comparable in size to terrestrial fluxes from individual land cover classes of the region.
Thomas Lavergne, Atle Macdonald Sørensen, Stefan Kern, Rasmus Tonboe, Dirk Notz, Signe Aaboe, Louisa Bell, Gorm Dybkjær, Steinar Eastwood, Carolina Gabarro, Georg Heygster, Mari Anne Killie, Matilde Brandt Kreiner, John Lavelle, Roberto Saldo, Stein Sandven, and Leif Toudal Pedersen
The Cryosphere, 13, 49–78,Short summary
The loss of polar sea ice is an iconic indicator of Earth’s climate change. Many satellite-based algorithms and resulting data exist but they differ widely in specific sea-ice conditions. This spread hinders a robust estimate of the future evolution of sea-ice cover. In this study, we document three new climate data records of sea-ice concentration generated using satellite data available over the last 40 years. We introduce the novel algorithms, the data records, and their uncertainties.
Jesper Kamp, Henrik Skov, Bjarne Jensen, and Lise Lotte Sørensen
Atmos. Chem. Phys., 18, 6923–6938,Short summary
Measurements of mercury fluxes over snow surfaces are carried out at the High Arctic site at Villum Research Station in North Greenland. The measurements were carried out from 23 April to 12 May during spring 2016, where atmospheric mercury depletion events (AMDEs) took place. The measurements showed a net emission of 8.9 ng m−2 min−1, with only a few depositional fluxes. GEM fluxes and atmospheric temperature measurements suggest that GEM emission partly could be affected by surface heating.
Heather Kyle, Søren Rysgaard, Feiyue Wang, and Mostafa Fayek
The Cryosphere Discuss.,
Revised manuscript not acceptedShort summary
Ikaite may play a major role in air-sea carbon fluxes, but its importance is not well known due to difficulties with quantification. A new technique for measuring ikaite was developed and tested and our findings showed this method is effective. Sea ice properties were also measured. Results indicate that ikaite is most abundant in the upper layers of first-year sea ice so will likely play a more significant role in air-sea carbon fluxes in future as seasonal sea ice becomes more common.
Norbert Pirk, Jakob Sievers, Jordan Mertes, Frans-Jan W. Parmentier, Mikhail Mastepanov, and Torben R. Christensen
Biogeosciences, 14, 3157–3169,
Qianqian Hong, Zhouqing Xie, Cheng Liu, Feiyue Wang, Pinhua Xie, Hui Kang, Jin Xu, Jiancheng Wang, Fengcheng Wu, Pengzhen He, Fusheng Mou, Shidong Fan, Yunsheng Dong, Haicong Zhan, Xiawei Yu, Xiyuan Chi, and Jianguo Liu
Atmos. Chem. Phys., 16, 13807–13821,Short summary
It is known that rapid industrialization in developing countries has led to an increase in air pollution. Here we firstly report the speciated atmospheric mercury during haze days based upon 1-year synchronous observations in an inland city in China. The findings provide direct evidence to understand the biogeochemical cycles of atmospheric mercury related to air pollution and an opportunity to evaluate the potential health risks of atmospheric mercury.
Dirk Notz, Alexandra Jahn, Marika Holland, Elizabeth Hunke, François Massonnet, Julienne Stroeve, Bruno Tremblay, and Martin Vancoppenolle
Geosci. Model Dev., 9, 3427–3446,Short summary
The large-scale evolution of sea ice is both an indicator and a driver of climate changes. Hence, a realistic simulation of sea ice is key for a realistic simulation of the climate system of our planet. To assess and to improve the realism of sea-ice simulations, we present here a new protocol for climate-model output that allows for an in-depth analysis of the simulated evolution of sea ice.
Nicolas-Xavier Geilfus, Ryan J. Galley, Brent G. T. Else, Karley Campbell, Tim Papakyriakou, Odile Crabeck, Marcos Lemes, Bruno Delille, and Søren Rysgaard
The Cryosphere, 10, 2173–2189,Short summary
The fate of ikaite precipitation within sea ice is poorly understood. In this study, we estimated ikaite precipitation of up to 167 µmol kg-1 within sea ice, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64–66 μmol kg-1. We estimated that more than half of the total ikaite precipitated was still contained in the ice when sea ice began to melt. The dissolution of the ikaite crystals in the water column kept the seawater pCO2 undersaturated.
William J. Burt, Helmuth Thomas, Lisa A. Miller, Mats A. Granskog, Tim N. Papakyriakou, and Leah Pengelly
Biogeosciences, 13, 4659–4671,Short summary
This study assesses the state of the carbon cycle in Hudson Bay, an ecologically important region of the Canadian Arctic. Results show that river input, sea-ice melt, biological activity, and general circulation patterns all have significant, and regionally dependent, impacts on the carbon cycle. The study also highlights the importance of detailed sampling procedures in highly stratified waters, and reveals that the deep Hudson Bay is primarily filled with waters of Pacific origin.
Sebastian Bathiany, Bregje van der Bolt, Mark S. Williamson, Timothy M. Lenton, Marten Scheffer, Egbert H. van Nes, and Dirk Notz
The Cryosphere, 10, 1631–1645,Short summary
We examine if a potential "tipping point" in Arctic sea ice, causing abrupt and irreversible sea-ice loss, could be foreseen with statistical early warning signals. We assess this idea by using several models of different complexity. We find robust and consistent trends in variability that are not specific to the existence of a tipping point. While this makes an early warning impossible, it allows to estimate sea-ice variability from only short observational records or reconstructions.
Odile Crabeck, Ryan Galley, Bruno Delille, Brent Else, Nicolas-Xavier Geilfus, Marcos Lemes, Mathieu Des Roches, Pierre Francus, Jean-Louis Tison, and Søren Rysgaard
The Cryosphere, 10, 1125–1145,Short summary
We present a new non-destructive X-ray-computed tomography technique to quantify the air volume fraction and produce separate 3-D images of air-volume inclusions in sea ice. While the internal layers showed air-volume fractions < 2 %, the ice–air interface (top 2 cm) showed values up to 5 %. As a result of the presence of large bubbles and higher air volume fraction measurements in sea ice, we introduce new perspectives on processes regulating gas exchange at the ice–atmosphere interface.
J. Sievers, L. L. Sørensen, T. Papakyriakou, B. Else, M. K. Sejr, D. Haubjerg Søgaard, D. Barber, and S. Rysgaard
The Cryosphere, 9, 1701–1713,
S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, S. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, and P. A. Mayewski
The Cryosphere, 9, 1213–1222,
A. S. Lansø, J. Bendtsen, J. H. Christensen, L. L. Sørensen, H. Chen, H. A. J. Meijer, and C. Geels
Biogeosciences, 12, 2753–2772,Short summary
The air-sea CO2 exchange is investigated in the coastal region of the Baltic Sea and Danish inner waters. The impact of short-term variability in atmospheric CO2 on the air-sea CO2 exchange is examined, and it is found that ignoring short-term variability in the atmospheric CO2 creates a significant bias in the CO2 exchange. Atmospheric short-term variability is not always included in studies of the air-sea CO2 exchange, but based on the present study, we recommend it to be so in the future.
N.-X. Geilfus, R. J. Galley, O. Crabeck, T. Papakyriakou, J. Landy, J.-L. Tison, and S. Rysgaard
Biogeosciences, 12, 2047–2061,Short summary
We investigated the evolution of inorganic carbon within landfast sea ice in Resolute Passage during the spring and summer melt period. Low TA and TCO2 concentrations observed in sea ice and brine were associated with the percolation of meltwater from melt ponds. Meltwater was continuously supplied to the ponds which prevented melt ponds from fully equilibrating with the atmospheric CO2 concentration, promoting a continuous uptake of CO2 from the atmosphere.
F. Slemr, H. Angot, A. Dommergue, O. Magand, M. Barret, A. Weigelt, R. Ebinghaus, E.-G. Brunke, K. A. Pfaffhuber, G. Edwards, D. Howard, J. Powell, M. Keywood, and F. Wang
Atmos. Chem. Phys., 15, 3125–3133,Short summary
• Longer-term mercury measurement in the Southern Hemisphere is compared. • Mercury, in terms of monthly and annual medians and averages, is more evenly distributed than hitherto believed. • Consequently, trends observed at one or a few sites are likely to be representative of the whole hemisphere, and smaller trends can be detected in shorter time periods. • We report a change in the trend sign at Cape Point from decreasing mercury concentrations in 1996-2004 to increasing ones since 2007.
J. Sievers, T. Papakyriakou, S. E. Larsen, M. M. Jammet, S. Rysgaard, M. K. Sejr, and L. L. Sørensen
Atmos. Chem. Phys., 15, 2081–2103,
N.-X. Geilfus, J.-L. Tison, S. F. Ackley, R. J. Galley, S. Rysgaard, L. A. Miller, and B. Delille
The Cryosphere, 8, 2395–2407,Short summary
Temporal evolution of pCO2 profiles in sea ice in the Bellingshausen Sea, Antarctica (Oct. 2007), shows that physical and thermodynamic processes control the CO2 system in the ice. We show that each cooling/warming event was associated with an increase/decrease in the brine salinity, TA, TCO2, and in situ brine and bulk ice pCO2. Thicker snow covers reduced the amplitude of these changes. Both brine and bulk ice pCO2 were undersaturated, causing the sea ice to act as a sink for atmospheric CO2.
O. Crabeck, B. Delille, D. Thomas, N.-X. Geilfus, S. Rysgaard, and J.-L. Tison
Biogeosciences, 11, 6525–6538,
T. Vihma, R. Pirazzini, I. Fer, I. A. Renfrew, J. Sedlar, M. Tjernström, C. Lüpkes, T. Nygård, D. Notz, J. Weiss, D. Marsan, B. Cheng, G. Birnbaum, S. Gerland, D. Chechin, and J. C. Gascard
Atmos. Chem. Phys., 14, 9403–9450,
D. Zanchettin, O. Bothe, C. Timmreck, J. Bader, A. Beitsch, H.-F. Graf, D. Notz, and J. H. Jungclaus
Earth Syst. Dynam., 5, 223–242,
J. Zhou, J.-L. Tison, G. Carnat, N.-X. Geilfus, and B. Delille
The Cryosphere, 8, 1019–1029,
A. Forest, P. Coupel, B. Else, S. Nahavandian, B. Lansard, P. Raimbault, T. Papakyriakou, Y. Gratton, L. Fortier, J.-É. Tremblay, and M. Babin
Biogeosciences, 11, 2827–2856,
L. L. Sørensen, B. Jensen, R. N. Glud, D. F. McGinnis, M. K. Sejr, J. Sievers, D. H. Søgaard, J.-L. Tison, and S. Rysgaard
The Cryosphere, 8, 853–866,
The Cryosphere, 8, 229–243,
F. Wang, A. Saiz-Lopez, A. S. Mahajan, J. C. Gómez Martín, D. Armstrong, M. Lemes, T. Hay, and C. Prados-Roman
Atmos. Chem. Phys., 14, 1323–1335,
R. J. Galley, B. G. T. Else, N.-X. Geilfus, A. A. Hare, D. Isleifson, L. Ryner, D. G. Barber, and S. Rysgaard
The Cryosphere Discuss.,
Revised manuscript not accepted
M. Vancoppenolle, D. Notz, F. Vivier, J. Tison, B. Delille, G. Carnat, J. Zhou, F. Jardon, P. Griewank, A. Lourenço, and T. Haskell
The Cryosphere Discuss.,
Revised manuscript not accepted
S. Rysgaard, D. H. Søgaard, M. Cooper, M. Pućko, K. Lennert, T. N. Papakyriakou, F. Wang, N. X. Geilfus, R. N. Glud, J. Ehn, D. F. McGinnis, K. Attard, J. Sievers, J. W. Deming, and D. Barber
The Cryosphere, 7, 707–718,
S. Tietsche, D. Notz, J. H. Jungclaus, and J. Marotzke
Ocean Sci., 9, 19–36,
O. Hertel, C. A. Skjøth, S. Reis, A. Bleeker, R. M. Harrison, J. N. Cape, D. Fowler, U. Skiba, D. Simpson, T. Jickells, M. Kulmala, S. Gyldenkærne, L. L. Sørensen, J. W. Erisman, and M. A. Sutton
Biogeosciences, 9, 4921–4954,
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Laura L. Landrum and Marika M. Holland
The Cryosphere, 16, 1483–1495,Short summary
High-latitude Arctic wintertime sea ice and snow insulate the relatively warmer ocean from the colder atmosphere. As the climate warms, wintertime Arctic conductive heat fluxes increase even when the sea ice concentrations remain high. Simulations from the Community Earth System Model Large Ensemble (CESM1-LE) show how sea ice and snow thicknesses, as well as the distribution of these thicknesses, significantly impact large-scale calculations of wintertime surface heat budgets in the Arctic.
Yunhe Wang, Xiaojun Yuan, Haibo Bi, Mitchell Bushuk, Yu Liang, Cuihua Li, and Haijun Huang
The Cryosphere, 16, 1141–1156,Short summary
We develop a regional linear Markov model consisting of four modules with seasonally dependent variables in the Pacific sector. The model retains skill for detrended sea ice extent predictions for up to 7-month lead times in the Bering Sea and the Sea of Okhotsk. The prediction skill, as measured by the percentage of grid points with significant correlations (PGS), increased by 75 % in the Bering Sea and 16 % in the Sea of Okhotsk relative to the earlier pan-Arctic model.
Charles Brunette, L. Bruno Tremblay, and Robert Newton
The Cryosphere, 16, 533–557,Short summary
Sea ice motion is a versatile parameter for monitoring the Arctic climate system. In this contribution, we use data from drifting buoys, winds, and ice thickness to parameterize the motion of sea ice in a free drift regime – i.e., flowing freely in response to the forcing from the winds and ocean currents. We show that including a dependence on sea ice thickness and taking into account a climatology of the surface ocean circulation significantly improves the accuracy of sea ice motion estimates.
Madison M. Smith, Marika Holland, and Bonnie Light
The Cryosphere, 16, 419–434,Short summary
Climate models represent the atmosphere, ocean, sea ice, and land with equations of varying complexity and are important tools for understanding changes in global climate. Here, we explore how realistic variations in the equations describing how sea ice melt occurs at the edges (called lateral melting) impact ice and climate. We find that these changes impact the progression of the sea-ice–albedo feedback in the Arctic and so make significant changes to the predicted Arctic sea ice.
Arttu Jutila, Stefan Hendricks, Robert Ricker, Luisa von Albedyll, Thomas Krumpen, and Christian Haas
The Cryosphere, 16, 259–275,Short summary
Sea-ice thickness retrieval from satellite altimeters relies on assumed sea-ice density values because density cannot be measured from space. We derived bulk densities for different ice types using airborne laser, radar, and electromagnetic induction sounding measurements. Compared to previous studies, we found high bulk density values due to ice deformation and younger ice cover. Using sea-ice freeboard, we derived a sea-ice bulk density parameterisation that can be applied to satellite data.
Mathieu Plante and L. Bruno Tremblay
The Cryosphere, 15, 5623–5638,Short summary
We propose a generalized form for the damage parameterization such that super-critical stresses can return to the yield with different final sub-critical stress states. In uniaxial compression simulations, the generalization improves the orientation of sea ice fractures and reduces the growth of numerical errors. Shear and convergence deformations however remain predominant along the fractures, contrary to observations, and this calls for modification of the post-fracture viscosity formulation.
Joey J. Voermans, Qingxiang Liu, Aleksey Marchenko, Jean Rabault, Kirill Filchuk, Ivan Ryzhov, Petra Heil, Takuji Waseda, Takehiko Nose, Tsubasa Kodaira, Jingkai Li, and Alexander V. Babanin
The Cryosphere, 15, 5557–5575,Short summary
We have shown through field experiments that the amount of wave energy dissipated in landfast ice, sea ice attached to land, is much larger than in broken ice. By comparing our measurements against predictions of contemporary wave–ice interaction models, we determined which models can explain our observations and which cannot. Our results will improve our understanding of how waves and ice interact and how we can model such interactions to better forecast waves and ice in the polar regions.
Marika M. Holland, David Clemens-Sewall, Laura Landrum, Bonnie Light, Donald Perovich, Chris Polashenski, Madison Smith, and Melinda Webster
The Cryosphere, 15, 4981–4998,Short summary
As the most reflective and most insulative natural material, snow has important climate effects. For snow on sea ice, its high reflectivity reduces ice melt. However, its high insulating capacity limits ice growth. These counteracting effects make its net influence on sea ice uncertain. We find that with increasing snow, sea ice in both hemispheres is thicker and more extensive. However, the drivers of this response are different in the two hemispheres due to different climate conditions.
Don Perovich, Madison Smith, Bonnie Light, and Melinda Webster
The Cryosphere, 15, 4517–4525,Short summary
During summer, Arctic sea ice melts on its surface and bottom and lateral edges. Some of this fresh meltwater is stored on the ice surface in features called melt ponds. The rest flows into the ocean. The meltwater flowing into the upper ocean affects ice growth and melt, upper ocean properties, and ocean ecosystems. Using field measurements, we found that the summer meltwater was equal to an 80 cm thick layer; 85 % of this meltwater flowed into the ocean and 15 % was stored in melt ponds.
Sönke Maus, Martin Schneebeli, and Andreas Wiegmann
The Cryosphere, 15, 4047–4072,Short summary
As the hydraulic permeability of sea ice is difficult to measure, observations are sparse. The present work presents numerical simulations of the permeability of young sea ice based on a large set of 3D X-ray tomographic images. It extends the relationship between permeability and porosity available so far down to brine porosities near the percolation threshold of a few per cent. Evaluation of pore scales and 3D connectivity provides novel insight into the percolation behaviour of sea ice.
Cyril Palerme and Malte Müller
The Cryosphere, 15, 3989–4004,Short summary
Methods have been developed for calibrating sea ice drift forecasts from an operational prediction system using machine learning algorithms. These algorithms use predictors from sea ice concentration observations during the initialization of the forecasts, sea ice and wind forecasts, and some geographical information. Depending on the calibration method, the mean absolute error is reduced between 3.3 % and 8.0 % for the direction and between 2.5 % and 7.1 % for the speed of sea ice drift.
Dongyang Fu, Bei Liu, Yali Qi, Guo Yu, Haoen Huang, and Lilian Qu
The Cryosphere, 15, 3797–3811,Short summary
Our results show three main sea ice drift patterns have different multiscale variation characteristics. The oscillation period of the third sea ice transport pattern is longer than the other two, and the ocean environment has a more significant influence on it due to the different regulatory effects of the atmosphere and ocean environment on sea ice drift patterns on various scales. Our research can provide a basis for the study of Arctic sea ice dynamics parameterization in numerical models.
Andrii Murdza, Arttu Polojärvi, Erland M. Schulson, and Carl E. Renshaw
The Cryosphere, 15, 2957–2967,Short summary
The strength of refrozen floes or piles of ice rubble is an important factor in assessing ice-structure interactions, as well as the integrity of an ice cover itself. The results of this paper provide unique data on the tensile strength of freeze bonds and are the first measurements to be reported. The provided information can lead to a better understanding of the behavior of refrozen ice floes and better estimates of the strength of an ice rubble pile.
H. Jakob Belter, Thomas Krumpen, Luisa von Albedyll, Tatiana A. Alekseeva, Gerit Birnbaum, Sergei V. Frolov, Stefan Hendricks, Andreas Herber, Igor Polyakov, Ian Raphael, Robert Ricker, Sergei S. Serovetnikov, Melinda Webster, and Christian Haas
The Cryosphere, 15, 2575–2591,Short summary
Summer sea ice thickness observations based on electromagnetic induction measurements north of Fram Strait show a 20 % reduction in mean and modal ice thickness from 2001–2020. The observed variability is caused by changes in drift speeds and consequential variations in sea ice age and number of freezing-degree days. Increased ocean heat fluxes measured upstream in the source regions of Arctic ice seem to precondition ice thickness, which is potentially still measurable more than a year later.
Ann Keen, Ed Blockley, David A. Bailey, Jens Boldingh Debernard, Mitchell Bushuk, Steve Delhaye, David Docquier, Daniel Feltham, François Massonnet, Siobhan O'Farrell, Leandro Ponsoni, José M. Rodriguez, David Schroeder, Neil Swart, Takahiro Toyoda, Hiroyuki Tsujino, Martin Vancoppenolle, and Klaus Wyser
The Cryosphere, 15, 951–982,Short summary
We compare the mass budget of the Arctic sea ice in a number of the latest climate models. New output has been defined that allows us to compare the processes of sea ice growth and loss in a more detailed way than has previously been possible. We find that that the models are strikingly similar in terms of the major processes causing the annual growth and loss of Arctic sea ice and that the budget terms respond in a broadly consistent way as the climate warms during the 21st century.
Ron Kwok, Alek A. Petty, Marco Bagnardi, Nathan T. Kurtz, Glenn F. Cunningham, Alvaro Ivanoff, and Sahra Kacimi
The Cryosphere, 15, 821–833,
Julienne Stroeve, Vishnu Nandan, Rosemary Willatt, Rasmus Tonboe, Stefan Hendricks, Robert Ricker, James Mead, Robbie Mallett, Marcus Huntemann, Polona Itkin, Martin Schneebeli, Daniela Krampe, Gunnar Spreen, Jeremy Wilkinson, Ilkka Matero, Mario Hoppmann, and Michel Tsamados
The Cryosphere, 14, 4405–4426,Short summary
This study provides a first look at the data collected by a new dual-frequency Ka- and Ku-band in situ radar over winter sea ice in the Arctic Ocean. The instrument shows potential for using both bands to retrieve snow depth over sea ice, as well as sensitivity of the measurements to changing snow and atmospheric conditions.
Leandro Ponsoni, François Massonnet, David Docquier, Guillian Van Achter, and Thierry Fichefet
The Cryosphere, 14, 2409–2428,Short summary
The continuous melting of the Arctic sea ice observed in the last decades has a significant impact at global and regional scales. To understand the amplitude and consequences of this impact, the monitoring of the total sea ice volume is crucial. However, in situ monitoring in such a harsh environment is hard to perform and far too expensive. This study shows that four well-placed sampling locations are sufficient to explain about 70 % of the inter-annual changes in the pan-Arctic sea ice volume.
H. Jakob Belter, Thomas Krumpen, Stefan Hendricks, Jens Hoelemann, Markus A. Janout, Robert Ricker, and Christian Haas
The Cryosphere, 14, 2189–2203,Short summary
The validation of satellite sea ice thickness (SIT) climate data records with newly acquired moored sonar SIT data shows that satellite products provide modal rather than mean SIT in the Laptev Sea region. This tendency of satellite-based SIT products to underestimate mean SIT needs to be considered for investigations of sea ice volume transports. Validation of satellite SIT in the first-year-ice-dominated Laptev Sea will support algorithm development for more reliable SIT records in the Arctic.
Mark S. Handcock and Marilyn N. Raphael
The Cryosphere, 14, 2159–2172,Short summary
Traditional methods of calculating the annual cycle of sea ice extent disguise the variation of amplitude and timing (phase) of the advance and retreat of the ice. We present a multiscale model that explicitly allows them to vary, resulting in a much improved representation of the cycle. We show that phase is the dominant contributor to the variability in the cycle and that the anomalous decay of Antarctic sea ice in 2016 was due largely to a change of phase.
Rebecca J. Rolph, Daniel L. Feltham, and David Schröder
The Cryosphere, 14, 1971–1984,Short summary
It is well known that the Arctic sea ice extent is declining, and it is often assumed that the marginal ice zone (MIZ), the area of partial sea ice cover, is consequently increasing. However, we find no trend in the MIZ extent during the last 40 years from observations that is consistent with a widening of the MIZ as it moves northward. Differences of MIZ extent between different satellite retrievals are too large to provide a robust basis to verify model simulations of MIZ extent.
Mark A. Tschudi, Walter N. Meier, and J. Scott Stewart
The Cryosphere, 14, 1519–1536,Short summary
A new version of a set of data products that contain the velocity of sea ice and the age of this ice has been developed. We provide a history of the product development and discuss the improvements to the algorithms that create these products. We find that changes in sea ice motion and age show a significant shift in the Arctic ice cover, from a pack with a high concentration of older ice to a sea ice cover dominated by younger ice, which is more susceptible to summer melt.
Angela Cheng, Barbara Casati, Adrienne Tivy, Tom Zagon, Jean-François Lemieux, and L. Bruno Tremblay
The Cryosphere, 14, 1289–1310,Short summary
Sea ice charts by the Canadian Ice Service (CIS) contain visually estimated ice concentration produced by analysts. The accuracy of manually derived ice concentrations is not well understood. The subsequent uncertainty of ice charts results in downstream uncertainties for ice charts users, such as models and climatology studies, and when used as a verification source for automated sea ice classifiers. This study quantifies the level of accuracy and inter-analyst agreement for ice charts by CIS.
Young Jun Kim, Hyun-Cheol Kim, Daehyeon Han, Sanggyun Lee, and Jungho Im
The Cryosphere, 14, 1083–1104,Short summary
In this study, we proposed a novel 1-month sea ice concentration (SIC) prediction model with eight predictors using a deep-learning approach, convolutional neural networks (CNNs). The proposed CNN model was evaluated and compared with the two baseline approaches, random-forest and simple-regression models, resulting in better performance. This study also examined SIC predictions for two extreme cases in 2007 and 2012 in detail and the influencing factors through a sensitivity analysis.
Shiming Xu, Lu Zhou, and Bin Wang
The Cryosphere, 14, 751–767,Short summary
Sea ice thickness parameters are key to polar climate change studies and forecasts. Airborne and satellite measurements provide complementary observational capabilities. The study analyzes the variability in freeboard and snow depth measurements and its changes with scale in Operation IceBridge, CryoVEx, CryoSat-2 and ICESat. Consistency between airborne and satellite data is checked. Analysis calls for process-oriented attribution of variability and covariability features of these parameters.
Valeria Selyuzhenok, Igor Bashmachnikov, Robert Ricker, Anna Vesman, and Leonid Bobylev
The Cryosphere, 14, 477–495,Short summary
This study explores a link between the long-term variations in the integral sea ice volume in the Greenland Sea and oceanic processes. We link the changes in the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) regional sea ice volume with the mixed layer, depth and upper-ocean heat content derived using the ARMOR dataset.
Chao Min, Longjiang Mu, Qinghua Yang, Robert Ricker, Qian Shi, Bo Han, Renhao Wu, and Jiping Liu
The Cryosphere, 13, 3209–3224,Short summary
Sea ice volume export through the Fram Strait has been studied using varied methods, however, mostly in winter months. Here we report sea ice volume estimates that extend over summer seasons. A recent developed sea ice thickness dataset, in which CryoSat-2 and SMOS sea ice thickness together with SSMI/SSMIS sea ice concentration are assimilated, is used and evaluated in the paper. Results show our estimate is more reasonable than that calculated by satellite data only.
M. Jeffrey Mei, Ted Maksym, Blake Weissling, and Hanumant Singh
The Cryosphere, 13, 2915–2934,Short summary
Sea ice thickness is hard to measure directly, and current datasets are very limited to sporadically conducted drill lines. However, surface elevation is much easier to measure. Converting surface elevation to ice thickness requires making assumptions about snow depth and density, which leads to large errors (and may not generalize to new datasets). A deep learning method is presented that uses the surface morphology as a direct predictor of sea ice thickness, with testing errors of < 20 %.
Pierre Rampal, Véronique Dansereau, Einar Olason, Sylvain Bouillon, Timothy Williams, Anton Korosov, and Abdoulaye Samaké
The Cryosphere, 13, 2457–2474,Short summary
In this article, we look at how the Arctic sea ice cover, as a solid body, behaves on different temporal and spatial scales. We show that the numerical model neXtSIM uses a new approach to simulate the mechanics of sea ice and reproduce the characteristics of how sea ice deforms, as observed by satellite. We discuss the importance of this model performance in the context of simulating climate processes taking place in polar regions, like the exchange of energy between the ocean and atmosphere.
Alberto Alberello, Miguel Onorato, Luke Bennetts, Marcello Vichi, Clare Eayrs, Keith MacHutchon, and Alessandro Toffoli
The Cryosphere, 13, 41–48,Short summary
Existing observations do not provide quantitative descriptions of the floe size distribution for pancake ice floes. This is important during the Antarctic winter sea ice expansion, when hundreds of kilometres of ice cover around the Antarctic continent are composed of pancake floes (D = 0.3–3 m). Here, a new set of images from the Antarctic marginal ice zone is used to measure the shape of individual pancakes for the first time and to infer their size distribution.
Frédéric Laliberté, Stephen E. L. Howell, Jean-François Lemieux, Frédéric Dupont, and Ji Lei
The Cryosphere, 12, 3577–3588,Short summary
Ice that forms over marginal seas often gets anchored and becomes landfast. Landfast ice is fundamental to the local ecosystems, is of economic importance as it leads to hazardous seafaring conditions and is also a choice hunting ground for both the local population and large predators. Using observations and climate simulations, this study shows that, especially in the Canadian Arctic, landfast ice might be more resilient to climate change than is generally thought.
Iina Ronkainen, Jonni Lehtiranta, Mikko Lensu, Eero Rinne, Jari Haapala, and Christian Haas
The Cryosphere, 12, 3459–3476,Short summary
We quantify the sea ice thickness variability in the Bay of Bothnia using various observational data sets. For the first time we use helicopter and shipborne electromagnetic soundings to study changes in drift ice of the Bay of Bothnia. Our results show that the interannual variability of ice thickness is larger in the drift ice zone than in the fast ice zone. Furthermore, the mean thickness of heavily ridged ice near the coast can be several times larger than that of fast ice.
Edward W. Blockley and K. Andrew Peterson
The Cryosphere, 12, 3419–3438,Short summary
Arctic sea-ice prediction on seasonal time scales is becoming increasingly more relevant to society but the predictive capability of forecasting systems is low. Several studies suggest initialization of sea-ice thickness (SIT) could improve the skill of seasonal prediction systems. Here for the first time we test the impact of SIT initialization in the Met Office's GloSea coupled prediction system using CryoSat-2 data. We show significant improvements to Arctic extent and ice edge location.
Jeff K. Ridley and Edward W. Blockley
The Cryosphere, 12, 3355–3360,Short summary
The climate change conference held in Paris in 2016 made a commitment to limiting global-mean warming since the pre-industrial era to well below 2 °C and to pursue efforts to limit the warming to 1.5 °C. Since global warming is already at 1 °C, the 1.5 °C can only be achieved at considerable cost. It is thus important to assess the risks associated with the higher target. This paper shows that the decline of Arctic sea ice, and associated impacts, can only be halted with the 1.5 °C target.
Aleksey Malinka, Eleonora Zege, Larysa Istomina, Georg Heygster, Gunnar Spreen, Donald Perovich, and Chris Polashenski
The Cryosphere, 12, 1921–1937,Short summary
Melt ponds occupy a large part of the Arctic sea ice in summer and strongly affect the radiative budget of the atmosphere–ice–ocean system. The melt pond reflectance is modeled in the framework of the radiative transfer theory and validated with field observations. It improves understanding of melting sea ice and enables better parameterization of the surface in Arctic atmospheric remote sensing (clouds, aerosols, trace gases) and re-evaluating Arctic climatic feedbacks at a new accuracy level.
Peng Lu, Matti Leppäranta, Bin Cheng, Zhijun Li, Larysa Istomina, and Georg Heygster
The Cryosphere, 12, 1331–1345,Short summary
It is the first time that the color of melt ponds on Arctic sea ice was quantitatively and thoroughly investigated. We answer the question of why the color of melt ponds can change and what the physical and optical reasons are that lead to such changes. More importantly, melt-pond color was provided as potential data in determining ice thickness, especially under the summer conditions when other methods such as remote sensing are unavailable.
Lu Zhou, Shiming Xu, Jiping Liu, and Bin Wang
The Cryosphere, 12, 993–1012,Short summary
This work proposes a new data synergy method for the retrieval of sea ice thickness and snow depth by using colocating L-band passive remote sensing and active laser altimetry. Physical models are adopted for the retrieval, including L-band radiation model and buoyancy relationship. Covariability of snow depth and total freeboard is further utilized to mitigate resolution differences and improve retrievability. The method can be applied to future campaigns including ICESat-2 and WCOM.
Ross M. Lieblappen, Deip D. Kumar, Scott D. Pauls, and Rachel W. Obbard
The Cryosphere, 12, 1013–1026,Short summary
We imaged first-year sea ice using micro-computed tomography to visualize, capture, and quantify the 3-D complex structure of salt water channels weaving through sea ice. From these data, we then built a mathematical network to better understand the pathways transporting heat, gases, and salts between the ocean and the atmosphere. Powered with this structural knowledge, we can create new modeled brine channels for a given sea ice depth and temperature that accurately mimic field conditions.
Matthias Rabatel, Pierre Rampal, Alberto Carrassi, Laurent Bertino, and Christopher K. R. T. Jones
The Cryosphere, 12, 935–953,Short summary
Large deviations still exist between sea ice forecasts and observations because of both missing physics in models and uncertainties on model inputs. We investigate how the new sea ice model neXtSIM is sensitive to uncertainties in the winds. We highlight and quantify the role of the internal forces in the ice on this sensitivity and show that neXtSIM is better at predicting sea ice drift than a free-drift (without internal forces) ice model and is a skilful tool for search and rescue operations.
Friedrich Richter, Matthias Drusch, Lars Kaleschke, Nina Maaß, Xiangshan Tian-Kunze, and Susanne Mecklenburg
The Cryosphere, 12, 921–933,Short summary
L-band (1.4 GHz) brightness temperatures from ESA's Soil Moisture and Ocean Salinity SMOS mission have been used to derive thin sea ice thickness. However, the brightness temperature measurements can potentially be assimilated directly in forecasting systems reducing the data latency and providing a more consistent first guess. We studied the forward (observation) operator that translates geophysical sea ice parameters from the ECMWF Ocean ReAnalysis Pilot 5 (ORAP5) into brightness temperatures.
Jun Ono, Hiroaki Tatebe, Yoshiki Komuro, Masato I. Nodzu, and Masayoshi Ishii
The Cryosphere, 12, 675–683,Short summary
Sea ice in the Arctic Ocean has experienced rapid decline since the beginning of satellite observations. To assess the predictability of sea ice extent (SIE) in the Arctic Ocean and to clarify the underlying physical processes, we conducted prediction experiments using an initialized climate model (MIROC5). The present study suggests that subsurface ocean heat content originating from the North Atlantic contributes to the skillful prediction of winter SIE at lead times up to 11 months.
Agnieszka Herman, Karl-Ulrich Evers, and Nils Reimer
The Cryosphere, 12, 685–699,Short summary
In regions close to the ice edge, sea ice is composed of many separate ice floes of different sizes and shapes. Strong fragmentation is caused mainly by ice breaking by waves coming from the open ocean. At present, this process, although recognized as important for many other physical processes, is not well understood. In this study we present results of a laboratory study of ice breaking by waves, and we provide interpretation of those results that may guide analysis of other similar datasets.
Alek A. Petty, Julienne C. Stroeve, Paul R. Holland, Linette N. Boisvert, Angela C. Bliss, Noriaki Kimura, and Walter N. Meier
The Cryosphere, 12, 433–452,Short summary
There was significant scientific and media attention surrounding Arctic sea ice in 2016, due primarily to the record-warm air temperatures and low sea ice conditions observed at the start of the year. Here we quantify and assess the record-low monthly sea ice cover in winter, spring and fall, and the lack of record-low sea ice conditions in summer. We explore the primary drivers of these monthly sea ice states and explore the implications for improved summer sea ice forecasting.
Lettie A. Roach, Samuel M. Dean, and James A. Renwick
The Cryosphere, 12, 365–383,Short summary
This paper evaluates Antarctic sea ice simulated by global climate models against satellite observations. We find biases in high-concentration and low-concentration sea ice that are consistent across the population of 40 models, in spite of the differences in physics between different models. Targeted model experiments show that biases in low-concentration sea ice can be significantly reduced by enhanced lateral melt, a result that may be valuable for sea ice model development.
David W. Rees Jones and Andrew J. Wells
The Cryosphere, 12, 25–38,Short summary
Frazil or granular ice grows rapidly from turbulent water cooled beneath its freezing temperature. We analyse numerical models of a population of ice crystals to provide insight into the treatment of frazil ice in large-scale models and hence in the environment. We determine critical conditions for explosively rapid frazil growth. We show that frazil-ice processes impact whether a plume of ice shelf water beneath an Antarctic ice shelf intrudes at depth or reaches the end of the shelf.
Jamie G. L. Rae, Alexander D. Todd, Edward W. Blockley, and Jeff K. Ridley
The Cryosphere, 11, 3023–3034,Short summary
Several studies have highlighted links between Arctic summer storms and September sea ice extent in observations. Here we use model and reanalysis data to investigate the sensitivity of such links to the analytical methods used, in order to determine their robustness. The links were found to depend on the resolution of the model and dataset, the method used to identify storms and the time period used in the analysis. We therefore recommend caution when interpreting the results of such studies.
Amelia A. Marks, Maxim L. Lamare, and Martin D. King
The Cryosphere, 11, 2867–2881,Short summary
Arctic sea ice extent is declining rapidly. Prediction of sea ice trends relies on sea ice models that need to be evaluated with real data. A realistic sea ice environment is created in a laboratory by the Royal Holloway sea ice simulator and is used to show a sea ice model can replicate measured properties of sea ice, e.g. reflectance. Black carbon, a component of soot found in atmospheric pollution, is also experimentally shown to reduce the sea ice reflectance, which could exacerbate melting.
David Docquier, François Massonnet, Antoine Barthélemy, Neil F. Tandon, Olivier Lecomte, and Thierry Fichefet
The Cryosphere, 11, 2829–2846,Short summary
Our study provides a new way to evaluate the performance of a climate model regarding the interplay between sea ice motion, area and thickness in the Arctic against different observation datasets. We show that the NEMO-LIM model is good in that respect and that the relationships between the different sea ice variables are complex. The metrics we developed can be used in the framework of the Coupled Model Intercomparison Project 6 (CMIP6), which will feed the next IPCC report.
The Cryosphere, 11, 2711–2725,Short summary
It is often assumed that ocean waves break sea ice into floes with sizes depending on wavelength. The results of this modeling study (in agreement with some earlier observations and models) suggest that this is not the case; instead the sizes of ice floes produced by wave breaking depend only on ice thickness and mechanical properties. This may have important consequences for predicting sea ice response to oceanic and atmospheric forcing in regions where sea ice is influenced by waves.
Ron Kwok, Nathan T. Kurtz, Ludovic Brucker, Alvaro Ivanoff, Thomas Newman, Sinead L. Farrell, Joshua King, Stephen Howell, Melinda A. Webster, John Paden, Carl Leuschen, Joseph A. MacGregor, Jacqueline Richter-Menge, Jeremy Harbeck, and Mark Tschudi
The Cryosphere, 11, 2571–2593,Short summary
Since 2009, the ultra-wideband snow radar on Operation IceBridge has acquired data in annual campaigns conducted during the Arctic and Antarctic springs. Existing snow depth retrieval algorithms differ in the way the air–snow and snow–ice interfaces are detected and localized in the radar returns and in how the system limitations are addressed. Here, we assess five retrieval algorithms by comparisons with field measurements, ground-based campaigns, and analyzed fields of snow depth.
Assur, A.: Composition of sea ice and its tensile strength, U.S. Army snow ice and permafrost research establishment, research report 44, corps of engineers, Wilmette, Illinois, December 1960.
Barber D. G., Ehn, J. K., Pucko, M., Rysgaard, S., Papakyriakou, T., Deming, J., Galley, R., and Søgaard, D.: Frost flowers on young Arctic sea ice: The climatic, chemical and microbial significance of an emerging ice type, J. Geophys. Res.-Atmos., revised, 2014.
Bates, N. R. and Mathis, J. T.: The Arctic Ocean marine carbon cycle: evaluation of air-sea CO2 exchanges, ocean acidification impacts and potential feedbacks, Biogeosciences, 6, 2433–2459, https://doi.org/10.5194/bg-6-2433-2009, 2009.
Bennington, K. O.: Desalination features in natural sea ice, J. Glaciol., 6, 845–857, 1967.
Bischoff, J. L., Fitzpatrick, J. A., and Rosenbauer, R. J.: The solubility and stabilization of ikaite (CaCO3·6H2O) from 0° to 25 °C: Environmental and paleoclimatic implications for thinolite tufa, J. Geol., 101, 21–33, 1993.
Cavalieri, D. J. and Parkinson, C. L.: Arctic sea ice variability and trends, 1979–2010, The Cryosphere, 6, 881–889, https://doi.org/10.5194/tc-6-881-2012, 2012.
Cole, D. M. and Shapiro, L. H.: Observations of brine drainage networks and microstructure of first-year sea ice, J. Geophys. Res., 103, 21739–21750, 1998.
Cox, G. F. N. and Weeks, W. F.: Equations for determining the gas and brine volumes in sea ice samples, J. Glaciol., 29, 306–316, 1983.
Dieckmann, G. S., Nehrke, G., Papadimitriou, S., Göttlicher, J., Steininger, R., Kennedy, H., Wolf-Gladrow, D., and Thomas, S. N.: Calcium carbonate as ikaite crystals in Antarctic sea ice, Geophys. Res. Lett., 35, L08501, https://doi.org/10.1029/2008GL033540, 2008.
Dieckmann, G. S., Nehrke, G., Uhlig, C., Göttlicher, J., Gerland, S., Granskog, M. A., and Thomas, D. N.: Brief Communication: Ikaite (CaCO$_3 \cdot$6H2O) discovered in Arctic sea ice, The Cryosphere, 4, 227–230, https://doi.org/10.5194/tc-4-227-2010, 2010.
Domine, F., Taillandier, A. S., Simpson, W. R., and Severin, K.: Specific surface area, density and microstructure of frost flowers, Geophys. Res. Lett., 32, L13502, https://doi.org/10.1029/2005GL023245, 2005.
Eicken, H., Bock, C., Wittig, R., Miller, H., and Poertner, H.-O.: Magnetic resonance imaging of sea-ice pore fluids: methods and thermal evolution of pore microstructure, Cold Reg. Sci. Technol., 31, 207–225, 2000.
Else, B. G. T., Papakyriakou, T. N., Galley, R. J., Drennan, W. M., Miller, L. A., and Thomas, H.: Wintertime CO2 fluxes in an arctic polynya using eddy covariance: Evidence for enhanced air-sea gas transfer during ice formation, J. Geophys. Res., 116, C00G03 https://doi.org/10.1029/2010JC006760, 2011.
Else, B. G. T., Papakyriakou, T. N., Galley, R. J., Mucci, A., Gosselin, M., Miller, L. A., Shadwick, E. H., and Thomas, H.: Annual cycles of pCO$_2sw$ in the southeastern Beaufort Sea: New understandings of air-sea CO2 exchange in arctic polynya regions, J. Geophys. Res.-Oceans, 117, C00G13, https://doi.org/10.1029/2011JC007346, 2012.
Else, B. G. T., Galley, R. J., Lansard, B., Mucci, A., Papakyriakou, T. N., Brown, K., Tremblay, J.-É., Babb, D., Barber, D., Miller, L. A., and Rysgaard, S.: Further observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic Ocean) due to sea ice loss, Geophys. Res. Lett., 40, 1132–1137, https://doi.org/10.1002/grl.50268, 2013.
Geilfus, N.-X., Carnat, G., Papakyriakou, T., Tison, J.-L., Else, B., Thomas, H., Shadwick, E., and Delille, B.: Dynamics of pCO2 and related air-ice CO2 fluxes in the Arctic coastal zone (Amundsen Gulf, Beaufort Sea), J. Geophys. Res.-Oceans, 117, C00G10, https://doi.org/10.1029/2011JC007118, 2012.
Geilfus, N.-X., Carnat, G., Dieckmann, G. S., Halden, N., Nehrke, G., Papakyriakou, T., Tison, J.-L., and Delille, B.: First estimates of the contribution of CaCO3 precipitation to the release of CO2 to the atmosphere during young sea ice growth, J. Geophys. Res.-Oceans, 118, 244–255, https://doi.org/10.1029/2012JC007980, 2013a.
Geilfus, N.-X., Galley, R., Hare, A., Wang, F., Søgaard, D., and Rysgaard, S.: Ikaite and gypsum crystals observed in experimental and natural sea ice, Geophys. Res. Lett.. 40, 6362–6367, https://doi.org/10.1002/2013GL058479, 2013b.
Golden, K. M., Ackley, S. F., and Lytle, V. I.: The percolation phase transition in sea ice, Science, 282, 2238, https://doi.org/10.1126/science.282.5397.2238, 1998.
Grasshoff, K., Erhardt, M., and Krembling, K.: Methods of seawater analysis, 2nd revised and extended version, Verlag Chemie, Weinheim, Deefield Beach, Fla., 1983.
Hare, A., Wang, F., Barber, D., Gelfus, N.-X., Galley, R. J., and Rysgaard, S.: pH evolution in sea ice grown at an outdoor experimental facility, Mar. Chem., 154, 46–54, https://doi.org/10.1016/j.marchem.2013.04.007, 2013.
Hesse, K. F. and Küppers, H.: Refinement of the structure of Ikaite, CaCO3·6H2O, Zeitschrift für Kristallographie, 163, 227–231, 1983.
Lake, R. A. and Lewis, E. L.: Salt rejection by sea ice during growth, J. Geophys. Res., 75, 583–597, 1970.
Marion, G. M.: Carbonate mineral solubility at low temperatures in the Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3-CO2-H2O system, Geochim. Cosmochim. Ac., 65, 1883–1896, 2001.
Marion, G. M. and Kargel, J. S.: Cold Aqueous Planetary Geochemistry with FREZCHEM: From Modeling to the Search for Life at the Limits, Springer, Heideberg, 251 pp., 2008.
Marion, G. M., Farren, R. E., and Komrowski, A. J.: Alternative pathways for seawater freezing, Cold Reg, Sci. Technol., 29, 259–266, 1999.
Marion, G. M., Mironenko, M. V., and Roberts, M. W.: FREZCHEM: a geochemical model for cold aqueous solutions, Comput. Geosci., 36, 10–15, 2010.
Miller, L. A., Carnat, G., Else, B. G. T., Sutherland, N., and Papakyriakou, T.: Carbonate system evolution at the Arctic Ocean surface during autumn freeze-up, J. Geophys. Res., 116, C00G04, https://doi.org/10.1029/2011JC007143, 2011a.
Miller, L. A., Papakyriakou, T., Collins, R. E., Deming, J. W., Ehn, J. K., Macdonald, R. W., Mucci, A., Owens, O., Raudsepp, M., and Sutherland, N.: Carbon dynamics in sea ice: A winter flux time series, J. Geophys. Res.-Oceans, 116, C02028, https://doi.org/10.1029/2009JC006058, 2011b.
Millero, F. J.: Chemical Oceanography 4th edition, CRC Press 30, Taylor & Francis Group, Boca Raton, Florida, USA, 547 pp., 2006.
Nomura, D., Yoshikawa-Inoue, H., and Toyota, T.: The effect of sea-ice growth on air-sea CO2 flux in a tank experiment. Tellus, 58, 418–426, 2006.
Papakyriakou, T. and Miller, L.: Springtime CO2 exchange over seasonal sea ice in the Canadian Arctic Archipelago, Ann. Glaciol., 52, 215–224, 2011.
Parmentier, F. J. W., Christensen, T. R., Sørensen, L. L., Rysgaard, S., McGuire, A. D., Miller, P. A., and Walker, D. A.: The impact of a lower sea-ice extent on Arctic greenhouse-gas exchange, Nature Climate Change, 3, 195–202, https://doi.org/10.1038/nclimate1784, 2013.
Perovich, D. K. and Gow, A. J.: A quantitative description of sea ice inclusions, J. Geophys. Res., 101, 18327–18343, 1996.
Roscoe, H. K., Brooks, B., Jackson, A. V., Smith, M. H., Walker, S. J., Obbard, R. W., and Wolff, E. W.: Frost flowers in the laboratory: Growth, characteristics, aerosol and the underlying sea ice, J. Geophys. Res., 116, D12301, https://doi.org/10.1029/2010JD015144, 2011.
Rysgaard, S., Bendtsen, J., Delille, B., Dieckmann, G., Glud, R. N., Kennedy, H., Mortensen, J., Papadimitriou, S., Thomas, D., and Tison, J.-L.: Sea ice contribution to air-sea CO2 exchange in the Arctic and Southern Oceans, Tellus B, 63, 823–830, https://doi.org/10.1111/j.1600-0889.2011.00571.x, 2011.
Rysgaard, S., Glud, R. N., Lennert, K., Cooper, M., Halden, N., Leakey, R. J. G., Hawthorne, F. C., and Barber, D.: Ikaite crystals in melting sea ice – implications for pCO2 and pH levels in Arctic surface waters, The Cryosphere, 6, 901–908, https://doi.org/10.5194/tc-6-901-2012, 2012.
Rysgaard, S., Søgaard, D. H., Cooper, M., Pućko, M., Lennert, K., Papakyriakou, T. N., Wang, F., Geilfus, N. X., Glud, R. N., Ehn, J., McGinnis, D. F., Attard, K., Sievers, J., Deming, J. W., and Barber, D.: Ikaite crystal distribution in winter sea ice and implications for CO2 system dynamics, The Cryosphere, 7, 707–718, https://doi.org/10.5194/tc-7-707-2013, 2013.
Style, R. W. and Worster, M. G.: Frost flower formation on sea ice and lake ice, Geophys. Res. Lett., 36, L11501, https://doi.org/10.1029/2009GL037304, 2009.