Article
Meteorology & Atmospheric Sciences
Yang Li, Haijun Yang
Summary: This study uses a single-hemisphere 4-box model to investigate the low-frequency variability of the Atlantic meridional overturning circulation (AMOC). It suggests that the AMOC exhibits a self-sustained multicentennial oscillation when an enhanced mixing mechanism is introduced in the subpolar ocean. The study also shows that stochastic freshwater forcing can excite the multicentennial oscillation. These findings suggest the presence of an intrinsic multicentennial mode in the Atlantic Ocean.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Jon Robson, Matthew B. Menary, Rowan T. Sutton, Jenny Mecking, Jonathan M. Gregory, Colin Jones, Bablu Sinha, David P. Stevens, Laura J. Wilcox
Summary: Studies have shown that anthropogenic aerosol (AA) forcing leads to a strengthening of the Atlantic meridional overturning circulation (AMOC), and there is a strong correlation between surface heat loss over the subpolar North Atlantic (SPNA) and the forced strengthening of the AMOC. However, the AMOC response is not strongly related to the contribution of anomalous downwelling surface shortwave radiation to SPNA heat loss. The spread in AMOC response is primarily due to the variability in turbulent heat loss. Furthermore, models suggest that the large turbulent heat loss in models with strong AA forcing may be attributed to colder and drier air advected over the ocean, caused by greater AA-forced cooling over the upwind continents.
JOURNAL OF CLIMATE
(2022)
Article
Geosciences, Multidisciplinary
Sisam Shrestha, Brian J. Soden
Summary: Climate models predict a weakening of the atmospheric circulation, primarily manifested as a weakening of the zonally asymmetric circulation. The strengthening of the Pacific Walker Circulation contradicts this prediction, raising questions about the models' ability to accurately predict future changes in overturning circulations.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Yanfeng Wang, Ping Huang
Summary: Fire emissions in South America consistently decreased from 2003 to 2019, which can be attributed to unfavorable climatic conditions and the phase transition of the Atlantic Multidecadal Oscillation. Despite anthropogenic forcing exacerbating drought and fire risks, fire emissions and aerosol pollution in the southern Amazon and Pantanal region showed a consistent long-term decrease. This decrease is linked to climatic conditions that hindered fire intensification and spread, including increased humidity and slower surface wind speed.
NATURE COMMUNICATIONS
(2022)
Article
Meteorology & Atmospheric Sciences
Yona Silvy, Jean-Baptiste Sallee, Eric Guilyardi, Juliette Mignot, Clement Rousset
Summary: This study investigates the mechanisms driving regional ocean warming and its emergence from internal variability. It finds that the contribution of different processes can vary in time, affecting the time of emergence of subsurface temperature changes.
JOURNAL OF CLIMATE
(2022)
Article
Geosciences, Multidisciplinary
Shouwei Li, Wei Liu, Robert J. Allen, Jia-Rui Shi, Laifang Li
Summary: According to climate model simulations, anthropogenic greenhouse gases and aerosols have opposing effects on heat uptake and interbasin transport in the ocean. The storage and distribution of heat in oceans have been significantly influenced by these man-made aerosols and greenhouse gases since the industrial age. By using coupled climate model simulations, the effects of both aerosols and greenhouse gases are isolated and quantified. The results show that changes in ocean heat uptake and circulation due to aerosols have a greater impact on interbasin heat exchange than the changes caused by increasing greenhouse gases.
Article
Environmental Sciences
Simon A. Josey, Bablu Sinha
Summary: Research suggests that ocean heat content in the North Atlantic mixed layer is influenced by ocean heat transport and heat exchange with the atmosphere to the same degree, sparking debate on cold conditions in the subpolar North Atlantic at a time of pervasive warming. Uncertainties arise from various potential causes and characteristic timescales, highlighting the importance of resolving these uncertainties for understanding recent European weather extremes and declines in the Atlantic overturning circulation.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Levi G. Silvers, Kevin A. Reed, Allison A. Wing
Summary: Previous studies have found that surface warming leads to weakened tropical circulations, reduced convective anvil cloud fraction, and increased atmospheric static stability. The interaction between overturning circulations, surface temperature, and atmospheric moisture was investigated in this study using simulations from the Radiative-Convective Equilibrium Model Intercomparison Project. The results showed a large spread in the change of intensity of the overturning circulation, and a consistent decrease in the exchange of mass between the boundary layer and the midtroposphere. The magnitude of this decrease varied due to the range of responses in mean precipitation and mean precipitable water.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Geosciences, Multidisciplinary
Alexandre Audette, Robert A. Fajber, Paul J. Kushner, Yutian Wu, Yannick Peings, Gudrun Magnusdottir, Rosie Eade, Michael Sigmond, Lantao Sun
Summary: The PAMIP project separates the effects of sea ice loss and ocean surface warming on atmospheric transport and moisture, revealing a competitive relationship between the two and suggesting that climate change can have competing impacts on global energy transport from the tropics to the Arctic.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Torge Martin, Arne Biastoch
Summary: Increasing melting of the Greenland Ice Sheet is expected to affect water mass transformation in the subpolar North Atlantic and the meridional overturning circulation. Our experiments show the significant role of mesoscale ocean dynamics and atmosphere feedback in projecting the climate system's response to enhanced Greenland Ice Sheet melting.
Article
Multidisciplinary Sciences
Fabien Roquet, David Ferreira, Romain Caneill, Daniel Schlesinger, Gurvan Madec
Summary: The formation of sea ice in polar regions relies on the stability of the water column, which is maintained by a salinity gradient. This study highlights the importance of the thermal expansion coefficient (TEC) of seawater in the polar halocline maintenance. The research reveals that sea ice would not form even with excess precipitations if the near-freezing temperature TEC was not well below its ocean average value. This finding emphasizes the significance of nonlinear water properties in influencing the global climate and its implications for Earth and other planets.
Article
Environmental Sciences
Marisa Roch, Peter Brandt, Sunke Schmidtko
Summary: The warming climate is causing a strengthening of ocean stratification, which has significant impacts on various processes in the ocean. This study investigates the state and trend of different parameters characterizing ocean stratification and finds that the stratification maximum has increased in both hemispheres. Comparisons to mixed layer characteristics show that a strengthening stratification is accompanied by a warming and freshening of the mixed layer. Globally, the stratification maximum strengthens by 7-8% and the mixed layer deepens by 4 m during 2006-2021. These findings can help improve predictions on climate change impact on upper-ocean ecology and biogeochemistry.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Multidisciplinary Sciences
Mengrong Ding, Hailong Liu, Pengfei Lin, Yao Meng, Weipeng Zheng, Bo An, Yihua Luan, Yongqiang Yu, Zipeng Yu, Yiwen Li, Jinfeng Ma, Jian Chen, Kangjun Chen
Summary: Investigating oceanic variations at different spatial and temporal scales is crucial for understanding the impact of global climate change on the oceans. However, existing observational datasets are inadequate for studying long temporal scales and/or meso spatial scales of global ocean variability. In this study, a high-resolution global ocean simulation dataset is presented, which can accurately simulate the global ocean circulation and mesoscale eddies. This dataset provides highly resolved oceanic and flux variables, making it valuable for studying ocean variability at multiple scales.
Article
Geosciences, Multidisciplinary
Wei Wu, Yan Du, Yu-Kun Qian, Ju Chen, Xingwei Jiang
Summary: This study investigates the South Equatorial Current (SEC) in the Indian Ocean using drifters deployed off Sumatra-Java. The observations show a significant meander in the SEC, with a drifters moving southward over 1,100 km in 40 days along 100 degrees E. The meander is driven by a combination of geostrophic currents associated with the Seychelles-Chagos thermocline ridge and an anticyclonic eddy/Rossby wave, as well as ageostrophic currents induced by southeasterly winds.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Ann. E. Gargett
Summary: This study explores the prediction of turbulent vertical velocity in the ocean surface layer using a linear combination of two scale velocities. The analysis shows that including both wind and wave effects improves the accuracy of the prediction.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Green & Sustainable Science & Technology
Johann D. Bell, Inna Senina, Timothy Adams, Olivier Aumont, Beatriz Calmettes, Sangaalofa Clark, Morgane Dessert, Marion Gehlen, Thomas Gorgues, John Hampton, Quentin Hanich, Harriet Harden-Davies, Steven R. Hare, Glen Holmes, Patrick Lehodey, Matthieu Lengaigne, William Mansfield, Christophe Menkes, Simon Nicol, Yoshitaka Ota, Coral Pasisi, Graham Pilling, Chis Reid, Espen Ronneberg, Alex Sen Gupta, Katherine L. Seto, Neville Smith, Sue Taei, Martin Tsamenyi, Peter Williams
Summary: Climate change will impact the distribution of tuna in Pacific Small Island Developing States, potentially causing declines in fish catches and government revenue under high emissions scenarios. However, reducing greenhouse gas emissions could lead to sustainability for tuna-dependent Pacific Island economies. Regional cooperation within fisheries management organizations may help safeguard the benefits derived from tuna despite climate-induced shifts in fish distribution.
NATURE SUSTAINABILITY
(2021)
Article
Ecology
Antoine Regimbeau, Marko Budinich, Abdelhalim Larhlimi, Juan Jose Pierella Karlusich, Olivier Aumont, Laurent Memery, Chris Bowler, Damien Eveillard
Summary: This study proposes a new conceptual niche called metabolic niche, which resumes the whole metabolic capabilities of an organism, and explores the key genes essential for the metabolic niche through statistical analysis.
Article
Environmental Sciences
Anh Le-Duy Pham, Olivier Aumont, Lavenia Ratnarajah, Alessandro Tagliabue
Summary: Marine free-living bacteria play a crucial role in the cycling of essential biogeochemical elements, and their growth is regulated by nutrient availability, particularly iron. Understanding the factors limiting bacterial growth and their role in the iron cycle is important for understanding biogeochemical cycling.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Channing J. Prend, M. G. Keerthi, Marina Levy, Olivier Aumont, Sarah T. Gille, Lynne D. Talley
Summary: Primary productivity in the Southern Ocean is crucial for global biogeochemical cycles. This study reveals that year-to-year variations in surface chlorophyll (SChl), a proxy for phytoplankton biomass, are mainly influenced by sub-seasonal fluctuations, rather than low-frequency climate variability.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Olivier Berne, Lydiane Agier, Antoine Hardy, Emmanuel Lellouch, Olivier Aumont, Jerome Mariette, Tamara Ben-Ari
Summary: In the context of global warming, academics have started to examine the environmental and carbon footprint of their professional activities. Existing studies have shown that air travel frequency is related to the number of citations, but not to publication rate or h-index. However, a comprehensive survey of over 6000 scientists in France reveals that higher air travel is associated with higher publication rate and h-index, suggesting that flying is a means for scientists to gain and maintain visibility in their field.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Biodiversity Conservation
Lester Kwiatkowski, Olivier Torres, Olivier Aumont, James C. C. Orr
Summary: Studies have shown that the influence of increasing atmospheric CO2 and climate change on the marine CO2 system and ecosystems is mainly manifested in the variability of carbonate chemistry, including seasonal and diurnal variations. Models project that the future ocean will experience enhanced diurnal variability of pCO2 and [H+], which may impose higher metabolic costs on marine organisms.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Biodiversity Conservation
Leonard Dupont, Priscilla Le Mezo, Olivier Aumont, Laurent Bopp, Corentin Clerc, Christian Ethe, Olivier Maury
Summary: Despite the ecological and economic importance of high trophic levels (HTLs) in ocean carbon dynamics, their impact on passive and active processes is still largely unexplored, especially under climate change scenarios. This study compares two simulations of a global biogeochemical-ecosystem model with and without feedbacks from large marine animals, finding that these animals have little influence on anthropogenic carbon uptake under the RCP8.5 scenario but do affect low trophic level biomasses and ecosystem equilibrium.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Environmental Sciences
Raphael Bajon, Thierry Huck, Nicolas Grima, Christophe Maes, Bruno Blanke, Camille Richon, Xavier Couvelard
Summary: The world's oceans are facing a serious problem of plastic pollution, with 80% originating from mismanaged waste and river discharge near coastal areas. A study was conducted to examine the fate of this pollution by tracking the trajectories of neutral plastic particles released continuously for 24 years using currents from a global ocean-wave coupled model and a reference ocean-only model. The results showed that these particles accumulate at the surface in subtropical convergence zones, penetrate to depths of approximately 250 meters, and disperse over a wide range of latitudes. More particles (5.3%) remain at the surface with the wave-coupled model currents compared to the uncoupled model (2%), mainly due to upward vertical velocities caused by waves-induced Stokes transport.
MARINE POLLUTION BULLETIN
(2023)
Article
Geosciences, Multidisciplinary
M. G. Keerthi, C. J. Prend, O. Aumont, M. Levy
Summary: This study evaluates the contribution of small scales to annual fluctuations in phytoplankton biomass based on global satellite observations. It finds that high-frequency fluctuations have a dominant impact on sea surface chlorophyll concentrations.
Article
Ecology
Boris Sauterey, Guillaume Le Gland, Pedro Cermeno, Olivier Aumont, Marina Levy, Sergio M. Vallina
Summary: As climate change progresses, ecosystems are experiencing unprecedented warming and extreme heat events. However, little is known about the ability of oceanic phytoplankton communities to adapt to these changes, which play a crucial role in regulating Earth's climate. This study uses an eco-evolutionary model to simulate the adaptive response of marine phytoplankton to temperature changes. The results suggest that while phytoplankton can adapt to gradual temperature increases over a century, rapid and extreme temperature changes can lead to reduced primary productivity and potentially overestimated resilience to climate change in current models.
ECOLOGICAL MODELLING
(2023)
Article
Ecology
Alban Planchat, Lester Kwiatkowski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschoen, Tomas Lovato, Roland Seferian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jorg Schwinger, Jerry Tjiputra, John P. Dunne, Charles Stock
Summary: Ocean alkalinity plays a critical role in carbon uptake and buffering against acidification. However, the representation of alkalinity and the calcium carbonate cycle in Earth system models have been frequently overlooked. The transition from CMIP5 to CMIP6 shows improvements in alkalinity representation, likely due to model tuning or parameterizations.
Article
Ecology
Corentin Clerc, Laurent Bopp, Fabio Benedetti, Meike Vogt, Olivier Aumont
Summary: Filter-feeding gelatinous macrozooplankton (FFGM) are recognized as an essential component of the marine ecosystem. They have access to a wider range of organisms and can rapidly export organic matter to the deep ocean. FFGM substantially contribute to carbon export at depth, particularly in low-productivity regions.
Article
Ecology
Laurent Bopp, Olivier Aumont, Lester Kwiatkowski, Corentin Clerc, Leonard Dupont, Christian Ethe, Thomas Gorgues, Roland Seferian, Alessandro Tagliabue
Summary: This study uses two IPSL-CM versions to simulate divergent NPP responses to similar high-emission scenarios in the 21st century, identifying nitrogen fixation as the main driver of these differences. While the evaluation of these model versions does not help constrain future NPP projection uncertainties, the use of a more comprehensive version of PISCES suggests moderate changes in globally averaged N fixation in the 21st century.
Article
Green & Sustainable Science & Technology
Jerome Mariette, Odile Blanchard, Olivier Berne, Olivier Aumont, Julian Carrey, Annelaure Ligozat, Emmanuel Lellouch, Philippe-Emmanuel Roche, Gael Guennebaud, Joel Thanwerdas, Philippe Bardou, Gerald Salin, Elise Maigne, Sophie Servan, Tamara Ben-Ari
Summary: Scrutiny over the carbon footprint of research and higher education has increased, but direct comparisons are difficult due to the sensitivity of carbon footprint assessments to parameters and assumptions, highlighting the importance of massive data collection and curation.
ENVIRONMENTAL RESEARCH: INFRASTRUCTURE AND SUSTAINABILITY
(2022)
Article
Ecology
Marti Gali, Marcus Falls, Herve Claustre, Olivier Aumont, Raffaele Bernardello
Summary: Oceanic particulate organic carbon (POC) is a small but dynamic component of the global carbon cycle. Recent developments in biogeochemical models have improved the understanding of POC dynamics. Evaluation of a model using global simulations and observations shows good agreement at different spatiotemporal scales, with room for improvement in resolving regional differences.