Article
Geosciences, Multidisciplinary
K. Nakata, K. I. Ohshima, S. Nihashi
Summary: Recent in situ and high-resolution satellite observations have highlighted the importance of active frazil and associated high sea-ice production in Antarctic coastal polynyas. The spatial distribution of active-frazil area, predominantly found along East Antarctica, is influenced by offshore wind and air temperature, while ice production is mainly determined by offshore wind. This study presents the first mapping of active-frazil area for Antarctic coastal polynyas, with ice production rates exceeding 20 m/yr in some areas.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Oceanography
Joshua Coupe, Cheryl Harrison, Alan Robock, Alice DuVivier, Elizabeth Maroon, Nicole S. Lovenduski, Scott Bachman, Laura Landrum, Charles Bardeen
Summary: A large-scale nuclear war could lead to rapid global climate change due to the injection of soot into the stratosphere. In climate model simulations, global cooling causes expansion of sea ice in the Northern Hemisphere, but in the Southern Hemisphere, sea ice initially expands and then suddenly loses 30% of its volume in a single melting season in the largest nuclear war simulation.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
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
Lucie Bourreau, Etienne Pauthenet, Loic Le Ster, Baptiste Picard, Esther Portela, Jean-Baptiste Sallee, Clive R. McMahon, Robert Harcourt, Mark Hindell, Christophe Guinet, Sophie Bestley, Jean-Benoit Charrassin, Alice DuVivier, Zephyr Sylvester, Kristen Krumhardt, Stephanie Jenouvrier, Sara Labrousse
Summary: This study investigates the in situ chlorophyll fluorescence signal in Antarctic coastal polynyas during winter and identifies its main oceanographic drivers. The results show a significant fluorescence signal from February to April, with an additional signal in certain locations in August. The fluorescence signal was found to be associated with changes in water depth, mixed layer depth, water temperature, and salinity.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
S. Mcclish, S. M. Bushinsky
Summary: The Southern Ocean seasonal sea ice zone in spring is characterized by sea ice retreat and the development of phytoplankton blooms. Studies using biogeochemical profiling floats have found that higher net community production (bNCP) occurs when sea ice breakup happens early in the year, especially near topographic features that may increase micronutrient supply. This suggests that changes in Southern Ocean sea ice will influence future bNCP.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Christopher Horvat, Kelsey Bisson, Sarah Seabrook, Antonia Cristi, Lisa C. Matthes
Summary: While it has been believed that compact sea ice areas inhibit upper-ocean photosynthesis, recent observations have shown under-ice phytoplankton blooms in the Southern Ocean. This study presents evidence of widespread under-ice blooms in the Southern Ocean and identifies the conditions that support their growth. The findings suggest the need for further investigation into the mechanisms behind these blooms.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Limnology
Hongjun Song, Rubao Ji, Meibing Jin, Yun Li, Zhixuan Feng, Oystein Varpe, Cabell S. Davis
Summary: Recent rapid sea-ice changes in the Arctic Ocean have different regional impacts on phytoplankton bloom timing and primary productivity, with earlier and stronger blooms in shelf regions following earlier ice retreats and enhanced light availability, while weakened blooms and reduced primary production in the central Arctic, particularly in the Canada Basin, are attributed to a chain reaction triggered by earlier ice-melt and enhanced haline stratification. Recognizing and quantifying these regional links will improve projections of biogeochemical cycles and trophic flows in Arctic marine ecosystems.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Geosciences, Multidisciplinary
Kate E. Ashley, Robert McKay, Johan Etourneau, Francisco J. Jimenez-Espejo, Alan Condron, Anna Albot, Xavier Crosta, Christina Riesselman, Osamu Seki, Guillaume Mass, Nicholas R. Golledge, Edward Gasson, Daniel P. Lowry, Nicholas E. Barrand, Katelyn Johnson, Nancy Bertler, Carlota Escutia, Robert Dunbar, James A. Bendle
Summary: In recent decades, Antarctic sea-ice extent has increased, contrary to the decrease simulated by Earth system models. The circulation of water masses beneath large-cavity ice shelves may be a key driver of this phenomenon. Analysis of a Holocene sediment core off East Antarctica reveals that mid-Holocene ice shelf cavity expansion led to cooling of surface waters and sea-ice growth, slowing down basal ice shelf melting. Incorporating this feedback mechanism into global climate models is crucial for future projections of Antarctic changes.
CLIMATE OF THE PAST
(2021)
Article
Environmental Sciences
Hanna M. Kauko, Tore Hattermann, Thomas Ryan-Keogh, Asmita Singh, Laura de Steur, Agneta Fransson, Melissa Chierici, Tone Falkenhaug, Elvar H. Hallfredsson, Gunnar Bratbak, Tatiana Tsagaraki, Terje Berge, Qin Zhou, Sebastien Moreau
Summary: Understanding the dynamics of phytoplankton bloom phenology in the Atlantic sector of the Southern Ocean revealed the importance of sea ice retreat and zooplankton grazing in driving bloom initiation and termination, respectively. The study also highlighted the spatial correlation between primary productivity and topographic features, suggesting natural fertilization as a contributing factor. Further investigation into the identified bloom regimes in the area may help inform spatial management strategies and anticipate potential shifts in bloom timing due to environmental changes.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
G. W. K. Moore, S. E. L. Howell, M. Brady
Summary: The area to the north of Ellesmere Island and Greenland, known as the "Last Ice Area", contains the thickest ice in the Arctic and may serve as an important refuge for ice-dependent species facing extinction. However, recent observations show that this region is undergoing rapid changes that may affect its suitability as a refuge.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Nastasia J. Freyria, Nathalie Joli, Connie Lovejoy
Summary: The study shows the seasonal dynamics of microbial communities in the North Water region, indicating that summer communities are more variable, while autumn communities favor undescribed dinoflagellates. Despite nutrient input, autumn chlorophyll concentrations remained low.
SCIENTIFIC REPORTS
(2021)
Article
Ecology
Mark Hague, Marcello Vichi
Summary: The seasonality of sea ice in the Southern Ocean has a significant impact on the life cycle of phytoplankton, with research showing that growth of phytoplankton under the ice begins 4-5 weeks before ice retreat, rather than rapidly accumulating after retreat. Novel techniques using sea ice cover for higher light transfer and extreme low light adaptation of phytoplankton have been identified as mechanisms responsible for this early growth process.
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
Environmental Sciences
Ji-Hoon Oh, Kyung Min Noh, Hyung-Gyu Lim, Emilia Kyung Jin, Sang-Yoon Jun, Jong-Seong Kug
Summary: This study examines the impacts of Antarctic meltwater on surface phytoplankton biomass in the Southern Ocean. It finds that the enhanced stratification due to the meltwater leads to changes in surface nutrient concentrations, particularly a decrease in nitrate concentration and an increase in dissolved iron concentration. These changes can shift the nutrient availability in the ocean and impact the biomass of phytoplankton.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Fange Yue, Yanbin Li, Yanxu Zhang, Longquan Wang, Dan Li, Peipei Wu, Hongwei Liu, Lijin Lin, Dong Li, Ji Hu, Zhouqing Xie
Summary: Methylmercury distribution and biogeochemical cycle in Antarctic seas are poorly understood. This study reports high levels of methylmercury in unfiltered seawater from the Ross Sea to the Amundsen Sea, particularly in surface water. The high concentration is likely influenced by phytoplankton mass and the presence of sea-ice.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Fisheries
Rubao Ji, Jeffrey A. Runge, Cabell S. Davis, Peter H. Wiebe
Summary: This study investigates the spatio-temporal variability patterns and environmental drivers of the lipid-rich calanoid copepod, Calanus finmarchicus, in the Gulf of Maine using a regional plankton dataset collected over four decades. The results demonstrate strong synchrony of interannual variability among basins for the spring stock, driven mainly by internal population dynamics. The fall stock, on the other hand, shows weakened synchrony and is influenced by both internal mortality and external dilution loss. There appears to be no direct connection between the spring and fall stock, indicating seasonal or sub-seasonal scales of population variability and associated drivers.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Ecology
Casey Youngflesh, Yun Li, Heather J. Lynch, Karine Delord, Christophe Barbraud, Rubao Ji, Stephanie Jenouvrier
Summary: The study found that breeding success of different species in the Antarctic seabird community fluctuated relatively independently, resulting in low overall synchrony but occasional synchrony during extreme years. Compared to other seabird communities, Antarctic seabirds exhibited lower synchrony and higher niche separation. The results suggest that communities with small temporal variation for conditions where species respond differently and large temporal variation for conditions where species respond similarly may exhibit more synchronous dynamics.
Article
Ecology
Kanchana Bandara, Oystein Varpe, Frederic Maps, Rubao Ji, Ketil Eiane, Vigdis Tverberg
Summary: The study examined the diapause timing patterns of Calanus finmarchicus in high-latitude marine environments under short- and long-term environmental stochasticity using an individual-based model. It found that diapause entry and exit timing were robust to short-term environmental variability but could be altered by longer-term fluctuations in temperature and food availability. Despite environmental variability, diapause exit occurred asynchronously throughout the year, indicating a diversified bet hedging strategy to spread the risk of starvation mortality among offspring.
ECOLOGICAL MODELLING
(2021)
Article
Biodiversity Conservation
Stephanie Jenouvrier, Matthew C. Long, Christophe F. D. Coste, Marika Holland, Marlene Gamelon, Nigel Yoccoz, Bernt-Erik Saether
Summary: Detecting climate change impacts on wild populations is challenging due to natural climate variability, biotic and abiotic processes, and observation error. The concept of time of emergence helps distinguish anthropogenic climate change signals from natural climate variability, and a theoretical assessment of climate-driven signals in population dynamics is presented.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Fisheries
Justin J. Suca, Jonathan J. Deroba, David E. Richardson, Rubao Ji, Joel K. Llopiz
Summary: The study found that most forage fish species on the Northeast US shelf have increasing or stable shelf occupancy in both spring and fall, likely linked to gear shifts and increasing bottom temperature and salinity. However, exceptions include decreases in shelf occupancy by sand lance and decreases in habitat suitability for Atlantic herring in the fall.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Ecology
Remi Fay, Matthieu Authier, Sandra Hamel, Stephanie Jenouvrier, Martijn van de Pol, Emmanuelle Cam, Jean-Michel Gaillard, Nigel G. Yoccoz, Paul Acker, Andrew Allen, Lise M. Aubry, Christophe Bonenfant, Hal Caswell, Christophe F. D. Coste, Benjamin Larue, Christie Le Coeur, Marlene Gamelon, Kaitlin R. Macdonald, Maria Moiron, Alex Nicol-Harper, Fanie Pelletier, Jay J. Rotella, Celine Teplitsky, Laura Touzot, Caitlin P. Wells, Bernt-Erik Saether
Summary: Empirical studies are increasingly focusing on quantifying individual variation in demographic parameters, showing the importance of these patterns for evolutionary and ecological processes. Advanced techniques using multivariate mixed effect models face challenges, particularly when applied to Bernoulli variables. Simulation results suggest that the performance of mixed models varies across different scenarios, highlighting the need for tailored approaches based on species life-history strategies and data availability.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Article
Environmental Sciences
Carmen L. David, Rubao Ji, Caroline Bouchard, Haakon Hop, Jeffrey A. Hutchings
Summary: We used a bioenergetic model to simulate and test the growth of Arctic cod larvae in response to temperature and food availability. The model suggested that larvae need to increase food consumption in subzero temperatures to reach the observed length-at-age. The model's growth rate matched well with field observations but was higher than laboratory-derived rates.
ELEMENTA-SCIENCE OF THE ANTHROPOCENE
(2022)
Article
Fisheries
Justin J. Suca, Rubao Ji, Hannes Baumann, Kent Pham, Tammy L. Silva, David N. Wiley, Zhixuan Feng, Joel K. Llopiz
Summary: By using otolith microstructure analysis and particle tracking experiments, this study reveals the hatch and settlement dates of northern sand lance in the Gulf of Maine region, as well as the source-sink dynamics among sand lance habitats. The results show that Stellwagen Bank is a major source of larvae for the Great South Channel, while the Great South Channel primarily serves as a sink for larvae from Stellwagen Bank and Georges Bank. The retention of larvae on Georges Bank and Stellwagen Bank varies interannually in response to changes in local wind events.
FISHERIES OCEANOGRAPHY
(2022)
Article
Fisheries
Zhengchen Zang, Rubao Ji, Deborah R. Hart, Changsheng Chen, Liuzhi Zhao, Cabell S. Davis
Summary: This study developed a scope for growth (SFG) model driven by high-resolution hydrodynamic and biological models to assess the spatial and seasonal variability of scallop energy dynamics. The research showed that scallop growth potential and biogeography in the Northeast U.S. Shelf are influenced by temperature, food supply, and seasonal changes. Larger scallops are more likely to experience low or negative SFGs as they age, implying habitat contraction as they grow older.
FISHERIES OCEANOGRAPHY
(2022)
Letter
Limnology
Zhengchen Zang, Rubao Ji, Yonggang Liu, Changsheng Chen, Yun Li, Siqi Li, Cabell S. Davis
Summary: In this study, a time series of spring bloom magnitude was constructed using a self-organizing map algorithm, and the importance of silicate supply from the deep Scotian Shelf Water was revealed, providing a better understanding of mechanisms controlling the spring bloom magnitude in the Gulf of Maine.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2022)
Article
Biology
Hugh Ducklow, Megan Cimino, Kenneth H. Dunton, William R. Fraser, Russell R. Hopcroft, Rubao Ji, Arthur J. Miller, Mark D. Ohman, Heidi M. Sosik
Summary: The marine coastal region, accounting for only 10% of the global ocean area, contributes nearly 20% of its total primary production and over 80% of fisheries landings. Unicellular phytoplankton dominate primary production. Climate variability has impacted marine ecosystems, but it is too early to differentiate ecological responses to long-term climate trends.
Article
Ecology
Stephanie Jenouvrier, Lise Aubry, Silke van Daalen, Christophe Barbraud, Henri Weimerskirch, Hal Caswell
Summary: Individuals differ in many aspects, and these differences are not only due to individual traits, but also to individual stochasticity. Environmental conditions influence individual heterogeneity and stochasticity, thus affecting the demographic outcomes of populations.
Article
Environmental Sciences
Huizi Dong, Meng Zhou, Roshin P. Raj, Walker O. Smith Jr, Suennje L. Basedow, Rubao Ji, Carin Ashjian, Zhaoru Zhang, Ziyuan Hu
Summary: The strong mesoscale eddy activity in the northern Norwegian Sea has a significant impact on the phytoplankton biomass levels. Eddies induce negative or positive chlorophyll-a concentration anomalies through horizontal and vertical transport-mixing. Wind-eddy interactions also result in positive or negative chlorophyll-a concentration anomalies. Eddy-induced Ekman upwelling plays a key role in the positive chlorophyll-a concentration anomalies within anticyclonic eddies (ACEs), promoting nutrient transport and phytoplankton growth. The combined effects of wind-eddy interactions and seasonal shallowing of the mixed layer depth contribute to the large chlorophyll-a concentration anomalies in May and June.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Fisheries
Z. Zang, R. Ji, D. R. Hart, D. Jin, C. Chen, Y. Liu, C. S. Davis
Summary: In this study, time series of sea scallop size structures in three areas of the Mid-Atlantic Bight were analyzed to understand the drivers of interannual variability. The results showed that thermal stress was more associated with size structure changes in shallower regions, while fishing mortality was more influential in deeper regions. A model also predicted a decrease in maximum shell height and habitat contraction under warming conditions. The study highlighted the importance of adaptive management plans to mitigate potential socioeconomic impacts of size structure changes.
ICES JOURNAL OF MARINE SCIENCE
(2023)
Article
Environmental Sciences
Marlene Gamelon, Stephanie Jenouvrier, Melanie Lindner, Bernt-Erik Saether, Marcel E. Visser
Summary: The authors define the time of emergence, known as 'time of emergence' (ToE), as the time at which the signal of climate change in ecological processes emerges from the noise of ecosystem variability. They found that the time of emergence differs across different levels of biological organization, occurring earlier at the population level rather than at the trait or vital rate levels. This finding suggests that the population size of the great tit will experience an amplified climate change signal compared to its laying date and vital rates under the RCP 8.5 scenario.
NATURE CLIMATE CHANGE
(2023)
