Article
Geography, Physical
Anders E. Carlson, Brian L. Beard, Robert G. Hatfield, Matthew Laffin
Summary: Through sediment geochemistry analysis in the Bellingshausen Sea, this study infers the presence or absence of ice sheets on West Antarctica and the Antarctic Peninsula during the Last Interglacial. The evidence suggests that the West Antarctic Ice Sheet may have been absent during the Last Interglacial, consistent with previous ice core constraints.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Oceanography
Daniel N. Goldberg, Andrew G. Twelves, Paul R. Holland, Martin G. Wearing
Summary: Little is known about Antarctic subglacial hydrology, but it is believed that subglacial runoff enhances submarine melt locally through buoyancy effects. This study examines the effects of runoff on sea ice and oceanography on the Continental Shelf, and finds that runoff enhances localized melt and reduces summer sea ice volume. Runoff-driven melt and circulation may be an important missing process in regional Antarctic ocean models.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Statistics & Probability
Fiona E. Turner, Caitlin E. Buck, Julie M. Jones, Louise C. Sime, Irene Malmierca Vallet, Richard D. Wilkinson
Summary: By using previous Antarctic ice sheet reconstructions, water isotope ratios from ice cores, and simulator predictions, we created a model of the ice sheet during the Last Glacial Maximum. We used Markov chain Monte Carlo to sample from the posterior distribution and found ice sheet shapes that closely matched observations. The posterior distribution allowed us to quantify the uncertainty in the reconstructed shape, which is missing in other analyses.
JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES C-APPLIED STATISTICS
(2023)
Article
Meteorology & Atmospheric Sciences
Marina Duetsch, Eric J. Steig, Peter N. Blossey, Andrew G. Pauling
Summary: High-resolution simulations indicate that the collapse of the West Antarctic Ice Sheet would cause detectable isotopic changes at several locations, providing constraints on the past collapse. Elevated 818O levels at SkyTrain Ice Rise and elevated deuterium excess and 818O levels at Hercules Dome are the most significant signals.
JOURNAL OF CLIMATE
(2023)
Review
Ecology
Mayuri Pandey, Naresh Chandra Pant, Devsamridhi Arora, Rashmi Gupta
Summary: The Antarctic cryosphere has a significant impact on the global climate system by influencing ocean currents, the atmosphere, and sea level over long periods. The evolution of the Antarctic Ice Sheet has been directly associated with major global climatic events.
Article
Geosciences, Multidisciplinary
Karsten Gohl, Gabriele Uenzelmann-Neben, Johanna Gille-Petzoldt, Claus-Dieter Hillenbrand, Johann P. Klages, Steven M. Bohaty, Sandra Passchier, Thomas Frederichs, Julia S. Wellner, Rachel Lamb, German Leitchenkov
Summary: The major ice loss in the Amundsen Sea sector of the West Antarctic Ice Sheet is believed to have caused ice sheet collapses in warm periods like the Pliocene. Expedition 379 recovered sediments from late Miocene to Holocene, providing insights into sedimentation processes in response to climate changes. Analysis of seismic data revealed significant prograding sequences and prolonged ice-sheet retreat during a warm period in the mid-Pliocene, suggesting a highly dynamic West Antarctic Ice Sheet during the Pliocene.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Benjamin J. Wallis, Anna E. Hogg, J. Melchior van Wessem, Benjamin J. Davison, Michiel R. van den Broeke
Summary: An analysis of satellite observations from 2014 to 2021 reveals that glaciers on the west Antarctic Peninsula experienced an average summer speed-up of 12.4% and a maximum speed change of 22.3%. This indicates a strong sensitivity of these glaciers to seasonal variations in the ice-ocean-atmosphere system, emphasizing the importance of accounting for seasonal speed variations when assessing the mass balance and sea level contribution of the Antarctic Peninsula.
Review
Geochemistry & Geophysics
A. R. A. Aitken, L. Li, B. Kulessa, D. Schroeder, T. A. Jordan, J. M. Whittaker, S. Anandakrishnan, E. J. Dawson, D. A. Wiens, O. Eisen, M. J. Siegert
Summary: Understanding Antarctica's sedimentary basins is crucial for studying the evolution of tectonics, ice, ocean, and climate. However, limited knowledge is due to the remote location, harsh environment, and the challenges posed by ice and sea ice. Recent progress in data collection and interpretation techniques has allowed for mapping and characterization of these basins, which play a crucial role in ice-sheet dynamics and future change.
REVIEWS OF GEOPHYSICS
(2023)
Article
Geography, Physical
Sarah U. Neuhaus, Slawek M. Tulaczyk, Nathan D. Stansell, Jason J. Coenen, Reed P. Scherer, Jill A. Mikucki, Ross D. Powell
Summary: Understanding past ice sheet configurations is important for predicting future ice sheet dynamics and calibrating models. In the Ross Sea sector of Antarctica, recent research suggests that the grounding line of the West Antarctic Ice Sheet retreated and readvanced in response to changes in climate, contrary to previous hypotheses that attributed the motion to ice sheet dynamics and glacioisostatic rebound.
Article
Geosciences, Multidisciplinary
Andrew D. Wickert, Carlie Williams, Lauren J. Gregoire, Kerry L. Callaghan, Ruza F. Ivanovic, Paul J. Valdes, Lael Vetter, Carrie E. Jennings
Summary: By developing a marine-calibrated chronology of southern Laurentide Ice Sheet position, it was found that climatic warming after the Last Glacial Maximum caused the ice to retreat and advance in cycles lasting about 2,000 years. It was proposed that the retreat of ice led to cooling of the northern hemisphere through weakening of the Atlantic Meridional Overturning Circulation (AMOC), which in turn triggered ice-sheet readvance and ultimately strengthened the AMOC, leading to warming of the northern hemisphere. This ice-climate interaction was initiated by synchronous warming and ice retreat around 18.7-17.6 ka and reached its peak during the Younger Dryas.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Minmin Fu
Summary: During the last ice age, the presence of large ice sheets in North America caused increased precipitation and led to the formation of large lakes in the western United States. However, contrary to previous modeling studies, a new climate simulation called iTraCE showed that the peak in winter rainfall over the Great Basin occurred during the last deglaciation. This peak was driven by the strengthening and southward shift of the midlatitude jet, which was influenced by meltwater forcing, changing orbital conditions, and rising atmospheric CO2 levels.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Ian Bailey, Sidney Hemming, Brendan T. Reilly, Gavyn Rollinson, Trevor Williams, Michael E. Weber, Maureen E. Raymo, Victoria L. Peck, Thomas A. Ronge, Stefanie Brachfeld, Suzanne O'Connell, Lisa Tauxe, Jonathan P. Warnock, Linda Armbrecht, Fabricio G. Cardillo, Zhiheng Du, Gerson Fauth, Marga Garcia, Anna Glueder, Michelle Guitard, Marcus Gutjahr, Ivan Hernandez-Almeida, Frida S. Hoem, Ji-Hwan Hwang, Mutsumi Iizuka, Yuji Kato, Bridget Kenlee, Yasmina M. Martos, Lara F. Perez, Osamu Seki, Shubham Tripathi, Xufeng Zheng
Summary: Ice loss in West Antarctica has been the most severe in the past 30 years. Geologists have examined marine sedimentary records to find evidence of past episodes of instability in the West Antarctic Ice Sheet. Sediments in the Scotia Sea receive debris from West Antarctica and can provide valuable information. Analysis of sediment layers from this sea confirms their ice-rafted origin and suggests they were deposited during a warm period. The provenance of the debris indicates that it likely came from the Weddell Sea and/or Amundsen Sea, and their high concentrations in these layers can be attributed to dirty icebergs calved from the retreating ice sheet.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2022)
Article
Multidisciplinary Sciences
Philip J. Bart, Matthew Kratochvil
Summary: Geological records of ice sheet collapse provide insights into the retreat of the West Antarctic Ice Sheet. The study reconstructs the retreat process in the eastern Ross Sea continental shelf and the Whales Deep Basin, and estimates the duration and rate of retreat.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
M. Mar Flexas, Andrew F. Thompson, Michael P. Schodlok, Hong Zhang, Kevin Speer
Summary: The observed acceleration of ice shelf basal melt rates throughout West Antarctica could destabilize continental ice sheets and markedly increase global sea level. Explanations for decadal-scale melt intensification have focused on processes local to shelf seas surrounding the ice shelves. A suite of process-based model experiments, guided by CMIP6 forcing scenarios, show that freshwater forcing from the Antarctic Peninsula, propagated between marginal seas by a coastal boundary current, causes enhanced melting throughout West Antarctica.
Article
Geography, Physical
Emma Ownsworth, David Selby, Jeremy Lloyd, Paul Knutz, Sonke Szidat, John Andrews, Colm O'Cofaigh
Summary: A new study investigates the sediment core from central Baffin Bay to reconstruct the ice sheet history and sediment fluxes. Two dominant sediment/discharge sources, detrital carbonate and radio-genic felsic, are identified. The study also provides updated age constraints and further supports the theory of an ice shelf in northern Baffin Bay.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Meteorology & Atmospheric Sciences
Won Chang, Jiali Wang, Julian Marohnic, V. Rao Kotamarthi, Elisabeth J. Moyer
Article
Biology
Yawen Guan, Christian Sampson, J. Derek Tucker, Won Chang, Anirban Mondal, Murali Haran, Deborah Sulsky
JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS
(2019)
Article
Geosciences, Multidisciplinary
Won Chang, Sunghoon Kim, Heewon Chae
SPATIAL STATISTICS
(2020)
Article
Statistics & Probability
Matthew Plumlee, Taylor G. Asher, Won Chang, Matthew Bilskie
Summary: This article demonstrates the good forecasting performance of probabilistic hurricane storm surge forecasting using a small number of carefully chosen simulations by utilizing modern statistical tools and an optimal design criterion. The study also addresses the missing data and output handling issues in surge modeling, showing evidence of efficacy in comparison to existing methods through a case study on Hurricane Michael (2018).
ANNALS OF APPLIED STATISTICS
(2021)
Article
Business
Sunghoon Kim, Wayne S. DeSarbo, Won Chang
Summary: The study introduces a new spatial modeling approach to calibrate the potential impact of spatial dependency and heterogeneity on customer service and satisfaction measurements. By utilizing a hierarchical Bayes framework with geographical boundary effects, the proposed method shows improved performance compared to existing procedures.
INTERNATIONAL JOURNAL OF RESEARCH IN MARKETING
(2021)
Article
Computer Science, Interdisciplinary Applications
Jacob Tracy, Won Chang, Sarah St George Freeman, Casey Brown, Adriana Palma Nava, Patrick Ray
Summary: This paper introduces a data-driven dynamic emulation method that successfully simulates high-dimensional model outputs, overcoming challenges from traditional multivariate statistics. The method is demonstrated on a regional groundwater model in metropolitan Mexico City and successfully emulates the dynamic of land subsidence and aquifer level fluctuation, providing new methodological advances for computationally expensive planning and optimization applications.
ENVIRONMENTAL MODELLING & SOFTWARE
(2022)
Article
Mathematics, Interdisciplinary Applications
Saumya Bhatnagar, Won Chang, Seonjin Kim, Jiali Wang
Summary: Computer model calibration plays a key role in scientific and engineering problems. However, the existing standard calibration framework faces inferential issues when dealing with high-dimensional dependent data. To overcome this problem, we propose a new calibration framework based on deep neural networks, which can accurately estimate input parameters and quantify the uncertainty of the estimates.
SIAM-ASA JOURNAL ON UNCERTAINTY QUANTIFICATION
(2022)
Article
Geosciences, Multidisciplinary
Jaewoo Park, Won Chang, Boseung Choi
Summary: This article analyzes COVID-19 contact tracing data from Seoul to understand the spatial patterns of patient visits and detect local cluster centers. The study develops a novel interaction Neyman-Scott process to account for the complex behavior of cluster centers. The results show that the method can effectively describe the spatial patterns of patient visits and provide visualizations for public health interventions.
SPATIAL STATISTICS
(2022)
Article
Biology
Carter Allen, Yuzhou Chang, Brian Neelon, Won Chang, Hang J. Kim, Zihai Li, Qin Ma, Dongjun Chung
Summary: High throughput spatial transcriptomics (HST) is a rapidly emerging experimental technology that allows for analyzing gene expression in tissue samples at or near single-cell resolution. We developed SPRUCE, a Bayesian spatial multivariate finite mixture model, to identify distinct cellular sub-populations in HST data.
Article
Statistics & Probability
Won Chang, Bledar A. Konomi, Georgios Karagiannis, Yawen Guan, Murali Haran
Summary: Calibrating ice sheet models is challenging due to the nature of the data and the uncertainties in model parameters. However, a hierarchical latent variable model can overcome these challenges and provide improved projections for future ice-volume change.
ANNALS OF APPLIED STATISTICS
(2022)
Article
Environmental Sciences
Christopher K. Wikle, Abhirup Datta, Bhava Vyasa Hari, Edward L. Boone, Indranil Sahoo, Indulekha Kavila, Stefano Castruccio, Susan J. Simmons, Wesley S. Burr, Won Chang
Summary: Explainable AI is a sub-discipline of computer science and machine learning that aims to address the lack of uncertainty quantification and inability to do inference in machine learning and deep neural models. This article focuses on explaining which inputs are important in models for predicting environmental data, and describes three general methods for explainability.
Review
Biochemistry & Molecular Biology
Hyeongseon Jeon, Juan Xie, Yeseul Jeon, Kyeong Joo Jung, Arkobrato Gupta, Won Chang, Dongjun Chung
Summary: In this paper, power analysis for three types of gene expression profiling technologies, bulk RNA-seq, single-cell RNA-seq, and high-throughput spatial transcriptomics, is reviewed and discussed from a practical standpoint. Existing power analysis tools and recommendations are described for bulk RNA-seq and scRNA-seq experiments. Factors influencing power analysis are investigated for high-throughput spatial transcriptomics, as there are currently no power analysis tools available.
Article
Environmental Sciences
Jaehong Jeong, Won Chang
Summary: As the risk of climate change becomes more apparent, countries worldwide are actively searching for alternative energy sources. Wind energy presents great potential for future energy portfolios without negative environmental impacts. Understanding the spatio-temporal patterns of wind is crucial in developing energy plans at national and global levels.
Article
Clinical Neurology
Minki P. Lee, Kien Hoang, Sungkyu Park, Yun Min Song, Eun Yeon Joo, Won Chang, Jee Hyun Kim, Jae Kyoung Kim
Summary: Sleep is crucial for health and well-being, but collecting and analyzing accurate longitudinal sleep data can be challenging. Researchers propose a neural network model called SOMNI to impute missing sleep-activity data, allowing clinicians to monitor sleep-wake cycles of individuals with irregular sleep patterns.
Article
Geosciences, Multidisciplinary
Jiali Wang, Zhengchun Liu, Ian Foster, Won Chang, Rajkumar Kettimuthu, V. Rao Kotamarthi
Summary: This study develops a neural-network-based approach for emulating high-resolution precipitation data with greatly reduced computational cost, which trains on a combination of low- and high-resolution simulations to produce realistic results. Results show that CNNs trained by CGAN generated more physically reasonable results, better capturing data variability and extremes than conventional methods.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)