Article
Environmental Sciences
Donghui Yi, Alejandro Egido, Walter H. F. Smith, Laurence Connor, Christopher Buchhaupt, Dexin Zhang
Summary: This study characterizes the sea-ice elevation distribution using NASA's Operation IceBridge (OIB) Airborne Topographic Mapper (ATM) data over the Arctic Ocean. The aim is to improve the estimation of sea-ice freeboard. The results show that the sea-ice elevation distribution is positively skewed, and the exponentially modified Gaussian distribution is better suited for fitting the probability density function. The correlation characteristics of the elevation are characterized using the autocorrelation function and correlation length.
Article
Geosciences, Multidisciplinary
Rosemary Willatt, Julienne C. Stroeve, Vishnu Nandan, Thomas Newman, Robbie Mallett, Stefan Hendricks, Robert Ricker, James Mead, Polona Itkin, Rasmus Tonboe, David N. Wagner, Gunnar Spreen, Glen Liston, Martin Schneebeli, Daniela Krampe, Michel Tsamados, Oguz Demir, Jeremy Wilkinson, Matthias Jaggi, Lu Zhou, Marcus Huntemann, Ian A. Raphael, Arttu Jutila, Marc Oggier
Summary: This study investigated methods to estimate snow depth on sea ice using radar, and found that using polarimetry and waveform shape information can provide relatively accurate estimations.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Shengkai Zhang, Tong Geng, Chaohui Zhu, Jiaxing Li, Xiao Li, Benxin Zhu, Laixing Liu, Feng Xiao
Summary: This study utilizes data and images from Operation IceBridge (OIB) to derive Arctic sea ice freeboard estimates from 2009 to 2019. The spatial and temporal variations of the freeboard were analyzed based on the estimates. The study finds a decreasing trend in the annual average sea ice freeboard, but an obvious increase in multiyear ice freeboard was observed in 2014.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Environmental Sciences
Geoffrey Dawson, Jack Landy, Michel Tsamados, Alexander S. Komarov, Stephen Howell, Harry Heorton, Thomas Krumpen
Summary: Satellite observations have been constrained to winter months, but a new method using neural networks trained with summer images has enabled accurate measurements of pan-Arctic sea ice thickness. The results show that the freeboard distributions in May and September closely match expected patterns of sea ice melt, although CryoSat-2 freeboards underestimate ice thickness compared to other observations, especially over thicker multi-year sea ice. Addressing uncertainties in the conversion from radar freeboard to ice thickness is crucial for creating a comprehensive pan-Arctic summer sea ice thickness dataset.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Ming Li, Jiping Liu, Meng Qu, Zhanhai Zhang, Xi Liang
Summary: This study retrieves the Arctic sea ice lead fraction from AMSR2 data and validates it against MODIS images. The results show no significant trend but moderate interannual variation in the ice lead fraction over the past two decades. While the maximum width and total length of sea ice lead decrease significantly in the Arctic, the mean width does not show a significant change. The lead fraction in the Beaufort Sea varies widely, while in the Greenland Sea, it exhibits a significant increase.
Article
Geochemistry & Geophysics
Alessandro Di Bella, Ronald Kwok, Thomas W. K. Armitage, Henriette Skourup, Rene Forsberg
Summary: The CS2 SARIn data can retrieve multiple valid sea ice height estimates, increase the number of valid sea surface height retrievals, and reduce the uncertainty of sea ice thickness.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Oceanography
Jack C. Landy, Jerome Bouffard, Chris Wilson, Stefanie Rynders, Yevgeny Aksenov, Michel Tsamados
Summary: The study shows that utilizing an objective mapping approach to determine sea surface height from proximal lead samples located on the orbital track and nearby tracks can improve the precision of sea ice radar freeboard estimation. By analyzing the covariance of historic CryoSat-2 Arctic lead observations, researchers were able to determine optimal SSH and error estimates for sea ice floe locations, leading to up to 20% increase in radar freeboard precision. This new method can be generalized to all present and historic polar altimetry missions, providing a more accurate way to measure sea ice thickness in a warming climate.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Geosciences, Multidisciplinary
T. J. W. Wagner, I. Eisenman, H. C. Mason
Summary: The study found that equatorward sea ice drift consistently leads to loss of ice volume, and the impact on ice area depends on seasonal factors and background climate. When there is enough ice, drift may slightly expand ice area, but for thinner ice, drift during the melt season can cause cracks and substantial ice loss that persists throughout the year.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Engineering, Aerospace
Isobel R. Lawrence, Thomas W. K. Armitage, Michel C. Tsamados, Julienne C. Stroeve, Salvatore Dinardo, Andy L. Ridout, Alan Muir, Rachel L. Tilling, Andrew Shepherd
Summary: In this study, Sentinel-3A waveform data was processed to estimate Arctic sea level anomaly and radar freeboard, with comparisons to CryoSat-2 satellite results revealing some biases. By combining data from Sentinel-3A and 3B, the sampling resolution can be significantly improved.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Ruth Moorman, Andrew F. Thompson, Earle A. Wilson
Summary: The melt rates of West Antarctic ice shelves in the Amundsen Sea are influenced by decadal variations in the volume of warm water at their outlets, which are generally attributed to wind-driven variations in warm water transport. However, this study introduces a simple model that suggests interannual variations in coastal polynya buoyancy forcing can also generate large decadal-scale variations in thermocline depth, even with a fixed supply of warm water from the shelf-break. This model demonstrates feedbacks between basal melt rates and ice front stratification strength, capturing observed variations in near-coast thermocline depth and stratification strength, and proposing an alternative mechanism for warm water volume changes compared to wind-driven theories.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Claire L. Parkinson, Nicolo E. DiGirolamo
Summary: The satellite dataset spanning 42 years from 1979 to 2020 reveals recent losses in sea ice coverage in both the Arctic and Antarctic, with the Arctic experiencing record low sea ice extents while the Antarctic has seen record lows since 2015. The data also shows that globally, every calendar month has recorded a new monthly record low within the past 5 years, indicating a rapid decline in global sea ice coverage.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Renee Mie Fredensborg Hansen, Eero Rinne, Henriette Skourup
Summary: The study found that data from radar echoes can successfully distinguish different types of sea ice, and different classification algorithms have varying accuracy in classifying FYI and MYI.
Article
Environmental Sciences
Dexuan Sha, Younghyun Koo, Xin Miao, Anusha Srirenganathan, Hai Lan, Shorojit Biswas, Qian Liu, Alberto M. Mestas-Nunez, Hongjie Xie, Chaowei Yang
Summary: The study found that stresses from the ocean and atmosphere create cracks and leads in sea ice. By analyzing high spatial resolution aerial images, the research identified temperature and ice motion vorticity as the main factors influencing the formation of sea ice leads.
Article
Oceanography
Qing Qin, Zhaomin Wang, Chengyan Liu, Chen Cheng
Summary: This study reveals the existence of persistent open-ocean polynyas in the Cooperation Sea and investigates the atmospheric and oceanic mechanisms responsible for their formation. These findings offer a more comprehensive understanding of open-ocean polynyas in the Southern Ocean and have implications for various research fields, such as physical, biological, and biogeochemical studies of the Southern Ocean.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Oceanography
D. G. Babb, R. J. Galley, S. Kirillov, J. C. Landy, S. E. L. Howell, J. C. Stroeve, W. Meier, J. K. Ehn, D. G. Barber
Summary: The loss of multiyear sea ice in the Arctic Ocean has occurred primarily through two stepwise reductions: in 1989 and in 2006-2008. The first reduction was due to high export of multiyear ice, while the second reduction was a result of both high export and melt, as well as limited replenishment of multiyear ice. Although currently stable, reduced retention of older multiyear ice has led to a younger and thinner multiyear ice pack, potentially setting the stage for another reduction.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Engineering, Aerospace
Jacques Verron, Pascal Bonnefond, Ole Andersen, Fabrice Ardhuin, Muriel Berge-Nguyen, Suchandra Bhowmick, Denis Blumstein, Francois Boy, Laurent Brodeau, Jean-Francois Cretaux, Mei Ling Dabat, Gerald Dibarboure, Sara Fleury, Florent Garnier, Lionel Gourdeau, Karen Marks, Nadege Queruel, David Sandwell, Walter H. F. Smith, E. D. Zaron
Summary: The CNES/ISRO altimetric satellite SARAL/AltiKa, launched in February 2013, has provided valuable data for various scientific and operational applications. Despite the drift in the satellite’s orbit since July 2016, the specific contributions and innovations related to the use of the Ka-band have become increasingly prominent. The advantages of the Ka-band include reduced ionosphere effects and better resolution, but there are drawbacks such as attenuation during rain. This study aims to highlight the advancements of the Ka-band and its potential for future missions.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Engineering, Aerospace
Antoine Laforge, Sara Fleury, Salvatore Dinardo, Florent Garnier, Frederique Remy, Jerome Benveniste, Jerome Bouffard, Jonas Verley
Summary: The study analyzes the main steps of radar freeboard computation as part of the Cryo-SeaNice Project, aiming to quantify the impacts of each processing method and identify optimal strategies to improve freeboard estimations from SAR altimetry measurements.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Environmental Sciences
Gunther Heinemann, Sascha Willmes, Lukas Schefczyk, Alexander Makshtas, Vasilii Kustov, Irina Makhotina
Summary: The parameterization of ocean/sea-ice/atmosphere interaction processes is crucial for regional climate models in the Arctic, particularly in wintertime conditions. This study uses data from the Transarktika 2019 experiment to verify the CCLM model and compares its sea ice model simulations with MODIS data. The results show improved performance with a new set of parameterizations and good representation of the temperature, humidity, and wind structure of the troposphere in CCLM.
Article
Environmental Sciences
Gunther Heinemann, Clemens Druee, Pascal Schwarz, Alexander Makshtas
Summary: A one-year field campaign at the Tiksi observatory in the Laptev Sea area used SODAR/RASS measurements to investigate the atmospheric boundary layer with a focus on low-level jets during winter, revealing the presence and characteristics of LLJs as well as their main driving mechanism and the influence of local topography.
Article
Environmental Sciences
Guenther Heinemann, Rolf Zentek
Summary: LLJs are climatological features in polar regions, particularly associated with katabatic winds over Antarctic ice sheet slopes and barrier winds along the Antarctic Peninsula. Their frequencies are sensitive to relative decrease criteria, with high-speed LLJs most frequent over the ice sheet and barrier wind regions.
Article
Environmental Sciences
Andreas Preusser, Gunther Heinemann, Lukas Schefczyk, Sascha Willmes
Summary: Knowledge of wintertime sea-ice production in Arctic polynyas is crucial for understanding vertical mixing in the upper ocean. This study presents a MODIS-assisted temperature adjustment algorithm to correct atmospheric input data sets and improve the accuracy of polynya characteristics. The algorithm is based on atmospheric model simulations and has been applied to the Laptev Sea region. The results show a significant decrease in differences between different atmospheric products, and additional filter strategies have been employed to enhance the inclusion of leads in thin-ice thickness composites.
Article
Environmental Sciences
Gunther Heinemann, Clemens Druee, Alexander Makshtas
Summary: Measurements of the atmospheric boundary layer structure in the high Arctic were conducted using SODAR for three years. The results were used to verify a regional climate model and revealed the presence of topographical channeling effects and low-level jets. The analysis also showed a dipole structure of channeled wind at the exits of Shokalsky Strait. Overall, the study provides valuable insights into the ABL structure and the climatology of channeling events.
Article
Environmental Sciences
Florent Garnier, Marion Bocquet, Sara Fleury, Jerome Bouffard, Michel Tsamados, Frederique Remy, Gilles Garric, Aliette Chenal
Summary: The relatively stable conditions of the sea ice cover in the Antarctic seem to be changing recently, and it is important to provide estimates of sea ice thickness and volume to anticipate potential changes. The study found that sea ice thickness and volume have been decreasing, particularly after 2016, in all regions except the Amundsen-Bellingshausen sea sector. This may indicate significant ongoing changes in the Antarctic sea ice.
Article
Environmental Sciences
Elodie Da Silva, Emma R. Woolliams, Nicolas Picot, Jean-Christophe Poisson, Henriette Skourup, Geir Moholdt, Sara Fleury, Sajedeh Behnia, Vincent Favier, Laurent Arnaud, Jeremie Aublanc, Valentin Fouqueau, Nicolas Taburet, Julien Renou, Herve Yesou, Angelica Tarpanelli, Stefania Camici, Renee Mie Fredensborg Hansen, Karina Nielsen, Frederic Vivier, Francois Boy, Roger Fjortoft, Mathilde Cancet, Ramiro Ferrari, Ghislain Picard, Mohammad J. Tourian, Nicolaas Sneeuw, Eric Munesa, Michel Calzas, Adrien Paris, Emmanuel Le Meur, Antoine Rabatel, Guillaume Valladeau, Pascal Bonnefond, Sylvie Labroue, Ole Andersen, Mahmoud El Hajj, Filomena Catapano, Pierre Femenias
Summary: The Copernicus Sentinel-3 Surface Topography Mission (STM) Land Altimetry provides valuable elevation information for inland waters, sea ice, and land ice. The St3TART project aims to generalize the concept of Fiducial Reference Measurements (FRMs) to validate the STM measurements. A roadmap for the operational provision of FRMs has been developed, including guidelines for SI traceability, definition of measurement procedures, processing methods, and uncertainty budget estimations.
Article
Geography, Physical
Marion Bocquet, Sara Fleury, Fanny Piras, Eero Rinne, Heidi Sallila, Florent Garnier, Frederique Remy
Summary: This study aims to extend the Arctic radar freeboard time series back to 1995 by correcting technical issues. A multi-parameter neural network-based method is applied to calibrate different satellite altimetry data for consistency. The radar freeboard estimations from 1995 to 2021 are validated through comparisons with independent datasets.
Article
Geography, Physical
Florent Garnier, Sara Fleury, Gilles Garric, Jerome Bouffard, Michel Tsamados, Antoine Laforge, Marion Bocquet, Renee Mie Fredensborg Hansen, Frederique Remy
Summary: The altimetric snow depth (ASD) product is compared to various snow depth products in both the Arctic and Antarctic. Results show that ASD has a mean bias of about 6.5 cm compared to the alternative Ka-Ku DuST product in the Arctic. Validation data also demonstrate the consistency of ASD, with a correlation of 0.66 and a RMSE of about 6 cm in Arctic comparisons.
Article
Geography, Physical
Elena Zakharova, Svetlana Agafonova, Claude Duguay, Natalia Frolova, Alexei Kouraev
Summary: This study utilized Ku-band backscatter measurements from the Jason-2 and Jason-3 satellite missions to demonstrate the potential of radar altimetry for the retrieval of river ice phenology dates and ice thickness for the first time. The results show that the altimetric measurements are sensitive enough to detect the first appearance of ice and the beginning of thermal breakup on the lower Ob River. The study also reveals the uncertainties in ice event timing and river ice thickness retrievals, as well as the novel application of radar altimetry for predicting ice bridge road operations.
Article
Geography, Physical
Alexei V. Kouraev, Elena A. Zakharova, Andrey G. Kostianoy, Mikhail N. Shimaraev, Lev V. Desinov, Evgeny A. Petrov, Nicholas M. J. Hall, Frederique Remy, Andrey Ya. Suknev
Summary: This study analyzed the appearance of a giant ice ring and eddy in Lake Baikal in Russia using various satellite data, finding that water infiltration and warm eddies have significant impacts on ice cover. By tracking ice floe displacement, the researchers estimated the influence of eddy currents on the upper water layer.
Article
Meteorology & Atmospheric Sciences
Eugeny A. Zakharchuk, Natalia Tikhonova, Elena Zakharova, Alexei Kouraev
Summary: Free sea level oscillations in the Baltic Sea were studied in barotropic and baroclinic conditions using numerical experiments. Different spatial patterns of amplitudes and phases of the oscillations were identified, with distinct wave modes and specific regions showing significant differences in amplitudes and phases.
