Article
Geography, Physical
Jinfei Wang, Chao Min, Robert Ricker, Qian Shi, Bo Han, Stefan Hendricks, Renhao Wu, Qinghua Yang
Summary: The thickness of Antarctic sea ice plays a crucial role in the global climate system. The European Space Agency's Sea Ice Climate Change Initiative project provides sea ice thickness data from 2002 to 2012. The study compares the Envisat and ICESat satellite measurements of sea ice thickness, showing significant temporal and spatial variations. The differences between Envisat and ICESat may be attributed to overestimation of Envisat sea ice freeboard and uncertainties in snow depth and sea ice density measurements.
Article
Geography, Physical
Steven Fons, Nathan Kurtz, Marco Bagnardi
Summary: We estimate the snow depth and snow freeboard of Antarctic sea ice using the CS2WFA method. Comparisons with other observations show good agreement overall, with some discrepancies in certain regions and seasons. We present an 11+ year time series of sea ice thickness and volume, revealing small regional thickness changes and emphasizing the importance of reconciling and validating longer-term multi-sensor time series.
Article
Geography, Physical
Sebastian Skatulla, Riesna R. Audh, Andrea Cook, Ehlke Hepworth, Siobhan Johnson, Doru C. Lupascu, Keith MacHutchon, Rutger Marquart, Tommy Mielke, Emmanuel Omatuku, Felix Paul, Tokoloho Rampai, Jorg Schroder, Carina Schwarz, Marcello Vichi
Summary: During the SCALE Winter Cruise of the South African icebreaker SA Agulhas II, researchers sampled and analyzed different types of ice in the Antarctic marginal ice zone. The study found significant differences in salinity and mechanical properties between solitary pancake ice and consolidated pack ice.
Article
Geography, Physical
Na Li, Ruibo Lei, Petra Heil, Bin Cheng, Minghu Ding, Zhongxiang Tian, Bingrui Li
Summary: This study investigates the mass balance of snow and landfast ice (LFI) in Prydz Bay using observations from sea ice mass balance buoys. The results show that the annual maximum ice thickness and snow depth were 1.59+/-0.17 m and 0.11-0.76 m, respectively. It is argued that an increased understanding of snow processes, local atmospheric and oceanic conditions, as well as coastal morphology and bathymetry, is required to improve the Antarctic LFI modeling.
Article
Geosciences, Multidisciplinary
Sang-Moo Lee, Hoyeon Shi, Byung-Ju Sohn, Albin J. Gasiewski, Walter N. Meier, Gorm Dybkjaer
Summary: This study estimated snow depth on sea ice from 2003 to 2020 using satellite measurements, showing that reliable snow depth can be obtained through this method. It also found a decreasing trend in snow depth across the entire Arctic Ocean, as well as geographical differences in snow depth trends between multiyear ice areas and other regions.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Rosamaria Salvatori, Roberto Salzano, Mauro Valt, Riccardo Cerrato, Stefano Ghergo
Summary: This article discusses the importance of hyperspectral measurements on ice and snow cover, and introduces an updated version of the Snow/Ice Spectral Archive (SISpec 2.0) and its integration into a web portal with various functionalities and interoperability.
Article
Meteorology & Atmospheric Sciences
Eui-Jong Kang, Byung-Ju Sohn, Rasmus Tage Tonboe, Gorm Dybkjaer, Kenneth Holmlund, Jong-Min Kim, Chao Liu
Summary: This paper introduces a sea ice prognostic model that successfully simulates the physical properties of snow and ice over the Arctic Ocean during the winter season. The model utilizes a one-dimensional thermodynamic diffusion model, satellite data, and Lagrangian ice tracking, with high correlations between simulated variables and in situ measurements. The nudging of satellite-derived temperature data significantly improves the thermal structure of the model, serving as a key element for successful simulation of other variables.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2021)
Article
Meteorology & Atmospheric Sciences
Shengzhe Chen, Jiping Liu, Yifan Ding, Yuanyuan Zhang, Xiao Cheng, Yongyun Hu
Summary: The study evaluated the simulation of snow depth over Arctic sea ice by 31 CMIP6 models during 1993-2014. It found that while the models captured certain aspects of the observed climatology and variability, there were substantial discrepancies in specific details. Most models exhibited significant differences when depicting the observed changes in snow depth over the Arctic region.
ADVANCES IN ATMOSPHERIC SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Philipp Anhaus, Christian Katlein, Marcel Nicolaus, Stefanie Arndt, Arttu Jutila, Christian Haas
Summary: This study focuses on utilizing spectral features of transmitted radiation to retrieve snow depth under specific conditions, showing accurate retrieval is possible under certain circumstances, but atmospheric variations and light levels have an influence on the results.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Hoyeon Shi, Sang-Moo Lee, Byung-Ju Sohn, Albin J. Gasiewski, Walter N. Meier, Gorm Dybkjar, Sang-Woo Kim
Summary: This study aims to develop a new retrieval algorithm for snow depth, sea ice thickness, bulk density, and ice freeboard in the Arctic winter by combining CryoSat-2 with passive microwave and infrared measurements. The algorithm combines two parameterizations with hydrostatic balance and radar wave speed correction equations to obtain solutions for the four variables. The results show good agreement with airborne snow depth, total freeboard, and mooring ice draft measurements, and the retrieved multiyear sea ice bulk density is more consistent with in situ measurements compared to previous parameterizations.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Environmental Sciences
Xuewei Li, Qinghua Yang, Lejiang Yu, Paul R. Holland, Chao Min, Longjiang Mu, Dake Chen
Summary: The satellite observations from 2003 to 2020 reveal an extreme loss in sea ice thickness during 2010-2011. Analysis of the ice thickness budget shows that this loss was caused by a large export of multiyear ice through the Fram Strait. Additionally, high cloudiness and positive net surface energy flux anomalies contributed to enhanced sea ice melt during the summer months. The loss of multiyear ice made the Arctic sea ice more vulnerable to atmospheric anomalies and triggered a positive ice-albedo amplifying feedback, accelerating the loss of ice thickness.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Jessica Cartwright, Alexander D. Fraser, Richard Porter-Smith
Summary: Maps of backscatter anisotropy parameters from EUMETSAT ASCAT provide valuable data for cryospheric applications. The maps are calculated using ASCAT data from multiple platforms and utilize linear falloff and Fourier series parameterization to characterize the anisotropy. Users can access the maps through the provided link.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Environmental Sciences
Zhaoqing Dong, Lijian Shi, Mingsen Lin, Tao Zeng
Summary: This study developed a new method using a deep learning algorithm to retrieve snow depth over Arctic sea ice, which was compared with other commonly used methods. Microwave radiometer products showed thicker snow in early winter, and the seasonal variations significantly impacted the retrieval of sea ice thickness.
Article
Environmental Sciences
Haili Li, Chang-Qing Ke, Qinghui Zhu, Mengmeng Li, Xiaoyi Shen
Summary: Snowpack on sea ice plays a vital role in the Earth's climate system. This study proposes a regression analysis model for estimating snow depth and compares it with a deep learning model and a neural network model. The results show that the regression analysis-five variable long short-term memory model performs well in estimating snow depth.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Geochemistry & Geophysics
Xiaojing Hu, Xiaohua Hao, Jian Wang, Guanghui Huang, Hongyi Li, Qian Yang
Summary: This study investigates the feasibility of estimating seasonal snow depth using ICESat-2 satellite data in Altay, China. The results show that estimation may be inaccurate in mountainous areas but effective in flat regions. Land-cover types also affect the accuracy of the estimation.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Engineering, Aerospace
Thomas W. K. Armitage, Ron Kwok
Summary: The study explores the feasibility of retrieving sea ice freeboard and sea surface height in ice-covered oceans using SWOT data. It indicates that the specularity of radar backscatter over sea ice is influenced by ice age and morphology. Specific guidelines for data processing resolution are also provided.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
R. Kwok, G. F. Cunningham, S. Kacimi, M. A. Webster, N. T. Kurtz, A. A. Petty
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Oceanography
R. Kwok, S. Kacimi, M. A. Webster, N. T. Kurtz, A. A. Petty
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Oceanography
Gunnar Spreen, Laura de Steur, Dmitry Divine, Sebastian Gerland, Edmond Hansen, Ronald Kwok
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Oceanography
Severine Fournier, Tong Lee, Xiaochun Wang, Thomas W. K. Armitage, Ou Wang, Ichiro Fukumori, Ron Kwok
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Oceanography
Alek A. Petty, Nathan T. Kurtz, Ron Kwok, Thorsten Markus, Thomas A. Neumann
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Oceanography
James Morison, Ron Kwok, Suzanne Dickinson, Roger Andersen, Cecilia Peralta-Ferriz, David Morison, Ignatius Rigor, Sarah Dewey, John Guthrie
Summary: The study shows that the cyclonic mode of Arctic Ocean surface circulation is influenced by the Arctic Oscillation, with changes occurring with variations in the AO value. The complex cyclonic mode includes effects such as increased sea ice export, increased freshwater, and freshened Beaufort Sea.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Astronomy & Astrophysics
A. A. Petty, M. Bagnardi, N. T. Kurtz, R. Tilling, S. Fons, T. Armitage, C. Horvat, R. Kwok
Summary: The study evaluates surface classification schemes for sea ice using ICESat-2 data and Sentinel-2 satellite imagery, increasing confidence in freeboard products and deriving new estimates of sea ice state for the first winter season of data collection.
EARTH AND SPACE SCIENCE
(2021)
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)
Review
Geochemistry & Geophysics
Joseph A. MacGregor, Linette N. Boisvert, Brooke Medley, Alek A. Petty, Jeremy P. Harbeck, Robin E. Bell, J. Bryan Blair, Edward Blanchard-Wrigglesworth, Ellen M. Buckley, Michael S. Christoffersen, James R. Cochran, Beata M. Csatho, Eugenia L. De Marco, RoseAnne T. Dominguez, Mark A. Fahnestock, Sinead L. Farrell, S. Prasad Gogineni, Jamin S. Greenbaum, Christy M. Hansen, Michelle A. Hofton, John W. Holt, Kenneth C. Jezek, Lora S. Koenig, Nathan T. Kurtz, Ronald Kwok, Christopher F. Larsen, Carlton J. Leuschen, Caitlin D. Locke, Serdar S. Manizade, Seelye Martin, Thomas A. Neumann, Sophie M. J. Nowicki, John D. Paden, Jacqueline A. Richter-Menge, Eric J. Rignot, Fernando Rodriguez-Morales, Matthew R. Siegfried, Benjamin E. Smith, John G. Sonntag, Michael Studinger, Kirsty J. Tinto, Martin Truffer, Thomas P. Wagner, John E. Woods, Duncan A. Young, James K. Yungel
Summary: Operation IceBridge conducted by NASA over 13 years aimed to survey land and sea ice using airborne laser altimetry. With 968 science flights, OIB greatly improved our understanding of land ice and sea ice, leading to numerous unexpected discoveries and providing valuable data for future research on the cryosphere.
REVIEWS OF GEOPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
M. Bagnardi, N. T. Kurtz, A. A. Petty, R. Kwok
Summary: Comparing sea surface height anomalies (SSHA) estimates between ICESat-2 and CryoSat-2, this study found good agreement in both along-track and gridded monthly estimates, suggesting ICESat-2 complements the SSHA estimates from CryoSat-2.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Sahra Kacimi, Ron Kwok
Summary: Using data from ICESat-2 and CryoSat-2, this study examines the changes in snow depth, thickness, and volume of Arctic sea ice. The results show a decrease in snow depth and ice thickness, particularly for multiyear ice, over a three-year period from 2018 to 2021.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Craig M. Lee, Michael DeGrandpre, John Guthrie, Victoria Hill, Ron Kwok, James Morison, Christopher J. Cox, Hanumant Singh, Timothy P. Stanton, Jeremy Wilkinson
Summary: Understanding and predicting Arctic change requires broad and sustained observations, including satellite remote sensing and in situ observations. Over the past few decades, various autonomous platforms have been developed for observing the ice-free ocean, but face additional challenges.
Article
Engineering, Electrical & Electronic
Joel T. Johnson, Kenneth C. Jezek, Giovanni Macelloni, Marco Brogioni, Leung Tsang, Emmanuel P. Dinnat, Jeffrey P. Walker, Nan Ye, Sidharth Misra, Jeffrey R. Piepmeier, Rajat Bindlish, David M. LeVine, Peggy E. O'Neill, Lars Kaleschke, Mark J. Andrews, Caglar Yardim, Mustafa Aksoy, Michael Durand, Chi-Chih Chen, Oguz Demir, Alexandra Bringer, Julie Z. Miller, Shannon T. Brown, Ron Kwok, Tong Lee, Yann Kerr, Dara Entekhabi, Jinzheng Peng, Andreas Colliander, Steven Chan, Joseph A. MacGregor, Brooke Medley, Roger DeRoo, Mark Drinkwater
Summary: Microwave radiometry plays a crucial role in Earth observation, with brightness temperature measurements from 500-1400 MHz showing potential to enhance sensing depth, improve sea salinity perception, and increase sensitivity to soil moisture. However, challenges such as radio-frequency interference and spectrum limitations need to be addressed.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2021)
Article
Geography, Physical
Ron Kwok, Alek A. Petty, Marco Bagnardi, Nathan T. Kurtz, Glenn F. Cunningham, Alvaro Ivanoff, Sahra Kacimi
Summary: In the new versions of the ICESat-2 sea ice products, the algorithm for finding surface references used to estimate freeboard heights has been modified to only use specular leads. This change has resulted in a decrease of coverage by about 10-20% and an increase of 04 cm in composite means in the Arctic and Southern oceans.