Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (173)

Search Parameters:
Keywords = global ocean CO2

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
38 pages, 6505 KiB  
Review
Trends in Oil Spill Modeling: A Review of the Literature
by Rodrigo N. Vasconcelos, André T. Cunha Lima, Carlos A. D. Lentini, José Garcia V. Miranda, Luís F. F. de Mendonça, Diego P. Costa, Soltan G. Duverger and Elaine C. B. Cambui
Water 2025, 17(15), 2300; https://doi.org/10.3390/w17152300 - 2 Aug 2025
Viewed by 232
Abstract
Oil spill simulation models are essential for predicting the oil spill behavior and movement in marine environments. In this study, we comprehensively reviewed a large and diverse body of peer-reviewed literature obtained from Scopus and Web of Science. Our initial analysis phase focused [...] Read more.
Oil spill simulation models are essential for predicting the oil spill behavior and movement in marine environments. In this study, we comprehensively reviewed a large and diverse body of peer-reviewed literature obtained from Scopus and Web of Science. Our initial analysis phase focused on examining trends in scientific publications, utilizing the complete dataset derived after systematic screening and database integration. In the second phase, we applied elements of a systematic review to identify and evaluate the most influential contributions in the scientific field of oil spill simulations. Our analysis revealed a steady and accelerating growth of research activity over the past five decades, with a particularly notable expansion in the last two. The field has also experienced a marked increase in collaborative practices, including a rise in international co-authorship and multi-authored contributions, reflecting a more global and interdisciplinary research landscape. We cataloged the key modeling frameworks that have shaped the field from established systems such as OSCAR, OIL-MAP/SIMAP, and GNOME to emerging hybrid and Lagrangian approaches. Hydrodynamic models were consistently central, often integrated with biogeochemical, wave, atmospheric, and oil-spill-specific modules. Environmental variables such as wind, ocean currents, and temperature were frequently used to drive model behavior. Geographically, research has concentrated on ecologically and economically sensitive coastal and marine regions. We conclude that future progress will rely on the real-time integration of high-resolution environmental data streams, the development of machine-learning-based surrogate models to accelerate computations, and the incorporation of advanced biodegradation and weathering mechanisms supported by experimental data. These advancements are expected to enhance the accuracy, responsiveness, and operational value of oil spill modeling tools, supporting environmental monitoring and emergency response. Full article
(This article belongs to the Special Issue Advanced Remote Sensing for Coastal System Monitoring and Management)
Show Figures

Figure 1

32 pages, 6657 KiB  
Article
Mechanisms of Ocean Acidification in Massachusetts Bay: Insights from Modeling and Observations
by Lu Wang, Changsheng Chen, Joseph Salisbury, Siqi Li, Robert C. Beardsley and Jackie Motyka
Remote Sens. 2025, 17(15), 2651; https://doi.org/10.3390/rs17152651 - 31 Jul 2025
Viewed by 298
Abstract
Massachusetts Bay in the northeastern United States is highly vulnerable to ocean acidification (OA) due to reduced buffering capacity from significant freshwater inputs. We hypothesize that acidification varies across temporal and spatial scales, with short-term variability driven by seasonal biological respiration, precipitation–evaporation balance, [...] Read more.
Massachusetts Bay in the northeastern United States is highly vulnerable to ocean acidification (OA) due to reduced buffering capacity from significant freshwater inputs. We hypothesize that acidification varies across temporal and spatial scales, with short-term variability driven by seasonal biological respiration, precipitation–evaporation balance, and river discharge, and long-term changes linked to global warming and river flux shifts. These patterns arise from complex nonlinear interactions between physical and biogeochemical processes. To investigate OA variability, we applied the Northeast Biogeochemistry and Ecosystem Model (NeBEM), a fully coupled three-dimensional physical–biogeochemical system, to Massachusetts Bay and Boston Harbor. Numerical simulation was performed for 2016. Assimilating satellite-derived sea surface temperature and sea surface height improved NeBEM’s ability to reproduce observed seasonal and spatial variability in stratification, mixing, and circulation. The model accurately simulated seasonal changes in nutrients, chlorophyll-a, dissolved oxygen, and pH. The model results suggest that nearshore areas were consistently more susceptible to OA, especially during winter and spring. Mechanistic analysis revealed contrasting processes between shallow inner and deeper outer bay waters. In the inner bay, partial pressure of pCO2 (pCO2) and aragonite saturation (Ωa) were influenced by sea temperature, dissolved inorganic carbon (DIC), and total alkalinity (TA). TA variability was driven by nitrification and denitrification, while DIC was shaped by advection and net community production (NCP). In the outer bay, pCO2 was controlled by temperature and DIC, and Ωa was primarily determined by DIC variability. TA changes were linked to NCP and nitrification–denitrification, with DIC also influenced by air–sea gas exchange. Full article
Show Figures

Figure 1

13 pages, 8486 KiB  
Article
Shallow Submarine CO2 Emissions in Coastal Volcanic Areas Implication for Global Carbon Budget Estimates: The Case of Vulcano Island (Italy)
by Sofia De Gregorio, Marco Camarda, Antonino Pisciotta and Vincenzo Francofonte
Environments 2025, 12(6), 197; https://doi.org/10.3390/environments12060197 - 11 Jun 2025
Viewed by 572
Abstract
The Earth’s degassing is an important factor in evaluating global carbon budget estimates and understanding the carbon cycle. As a result, numerous studies have focused on this topic. However, current estimates predominantly focus on subaerial CO2 emissions and CO2 deep submarine [...] Read more.
The Earth’s degassing is an important factor in evaluating global carbon budget estimates and understanding the carbon cycle. As a result, numerous studies have focused on this topic. However, current estimates predominantly focus on subaerial CO2 emissions and CO2 deep submarine emissions, particularly along mid-ocean ridges (MORs), whereas very few and only spatially limited estimates of shallow submarine CO2 emissions have been reported, despite being widespread features of the seafloor. This study reports the results of measuring the dissolved CO2 concentrations in shallow submarine environments along the coast of Vulcano Island (Aeolian Islands, Italy). For the areas exhibiting the highest concentrations, we calculated the amount of diffuse degassing by computing the sea–air CO2 flux. The results revealed extremely high dissolved CO2 concentrations, reaching up to 24 vol.% in areas with visible hydrothermal activity, including one location far from the island’s main crater. Notably, elevated CO2 levels were also detected in areas with minimal or no apparent hydrothermal discharge, indicating the occurrence of diffuse degassing processes in these areas. In addition, the calculated diffuse degassing flux was comparable in magnitude to the CO2 flux directly emitted into the atmosphere from the island’s main bubbling pools. Full article
Show Figures

Figure 1

22 pages, 10685 KiB  
Article
The Co-Evolution of Paleoclimate, Paleoceanography, and Sedimentation in the Yanshan Basin, North China: Records from the Yangzhuang Formation of the Jixian Section
by Yan Zhang, Yaoqi Zhou, Mengchun Cao, Hui Tian and Xingcheng Yin
Minerals 2025, 15(6), 633; https://doi.org/10.3390/min15060633 - 11 Jun 2025
Viewed by 394
Abstract
The Yangzhuang Formation of the Mesoproterozoic Jixian System exhibits a well-developed carbonate sedimentary sequence. However, the carbonate cycles within the Yangzhuang Formation and their co-evolution with paleoclimate and paleoceanographic environment changes remain insufficiently studied. This study conducts a systematic investigation of the rhythmic [...] Read more.
The Yangzhuang Formation of the Mesoproterozoic Jixian System exhibits a well-developed carbonate sedimentary sequence. However, the carbonate cycles within the Yangzhuang Formation and their co-evolution with paleoclimate and paleoceanographic environment changes remain insufficiently studied. This study conducts a systematic investigation of the rhythmic layers of the Yangzhuang Formation within the Yanshan Basin, North China, through major and trace element analysis, rare earth element analysis, inorganic carbon isotope analysis, granulometric analysis, and time series analysis. The results show that the low content of terrigenous clastics (11.2%~32.6%), slow sedimentation rate (2.2–2.5 cm/ka), Mg/Ca molar ratio close to 1 (1.05–1.53), and small fluctuation of δ13Ccarb (−0.37‰~−0.05‰) in Member 3 of the Yangzhuang Formation constitutes the processes of co-evolution, along with a mid-phase fluctuation. It indicates the stable evolution of the sedimentary environment and slow ocean expansion speed. However, there is a fluctuating characteristic affected by the breakup of the Colombian supercontinent. The chemical and granulometric analysis of the red and gray layers shows that the terrigenous materials are mainly derived from the eolian sediments, with differences in the wind carrying materials. The time series analysis of the dense samples displays the coupling between the rhythm of the red and gray layers, the inorganic carbon isotope cycle, and the 15 ka precessional cycle in the Mesoproterozoic. We conclude that the rhythm of layers is mainly affected by the monsoon change driven by low-latitude solar radiation at that time, and the age of the Yangzhuang Formation is limited to 1550~1520 ± 2 Ma. The study of the Mesoproterozoic sequence using geochemical data from carbonate deposits reveals the underlying mechanism of global co-evolution during this period, providing a basis for understanding the evolution of the Mesoproterozoic Earth system. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
Show Figures

Figure 1

18 pages, 15631 KiB  
Article
Resolving the Faint Young Sun Paradox and Climate Extremes: A Unified Thermodynamic Closure Theory
by Hsien-Wang Ou
Climate 2025, 13(6), 116; https://doi.org/10.3390/cli13060116 - 2 Jun 2025
Viewed by 539
Abstract
Clouds play a central role in regulating incoming solar radiation and outgoing terrestrial emission; hence, they must be internally constrained to prognose Earth’s temperature. At the same time, planetary fluids are inherently turbulent, so the climate state would tend toward maximum entropy production—a [...] Read more.
Clouds play a central role in regulating incoming solar radiation and outgoing terrestrial emission; hence, they must be internally constrained to prognose Earth’s temperature. At the same time, planetary fluids are inherently turbulent, so the climate state would tend toward maximum entropy production—a generalized second law of thermodynamics. Incorporating these requirements, I have previously formulated an aquaplanet model to demonstrate that intrinsic water properties may strongly lower the climate sensitivity to solar irradiance, thereby resolving the faint young Sun paradox (FYSP). In this paper, I extend the model to include other external forcings and show that sensitivity to the reduced outgoing longwave radiation by the elevated pCO2 can be several times greater, but the global temperature remains capped at ~40 °C by the exponential increase in saturated vapor pressure. I further show that planetary albedo augmented by a tropical supercontinent may cool the climate sufficiently to cause tropical glaciation. And since the glacial edge is marked by above-freezing temperature, it abuts an open, co-zonal ocean, thereby obviating the “Snowball Earth” hypothesis. Our theory thus provides a unified framework for interpreting Earth’s diverse climates, including the FYSP, the warm extremes of the Cambrian and Cretaceous, and the tropical glaciations of the Precambrian. Full article
Show Figures

Graphical abstract

15 pages, 2210 KiB  
Article
Life Cycle Assessment of an Oscillating Water Column-Type Wave Energy Converter
by Heshanka Singhapurage, Pabasari A. Koliyabandara and Gamunu Samarakoon
Energies 2025, 18(10), 2600; https://doi.org/10.3390/en18102600 - 17 May 2025
Viewed by 637
Abstract
Among different kinds of renewable energy sources, ocean wave energy offers a promising source of low-carbon electricity. However, despite this potential, ocean wave energy systems can have notable environmental impacts, which remain underexplored. Environmental life cycle assessment (LCA) is a method that can [...] Read more.
Among different kinds of renewable energy sources, ocean wave energy offers a promising source of low-carbon electricity. However, despite this potential, ocean wave energy systems can have notable environmental impacts, which remain underexplored. Environmental life cycle assessment (LCA) is a method that can be used to evaluate the environmental impact of these systems. But few LCAs have been conducted for wave energy converters (WECs), and no prior studies specifically address onshore oscillating water column (OWC) devices, leaving a clear gap in this field. This research provides a cradle-to-gate LCA for an OWC device, using the 500 kW LIMPET OWC plant, located on the Isle of Islay in Scotland, as a case study. The assessment investigated the environmental impacts of the plant across 19 impact categories. OpenLCA 2.0 software was used for the analysis, with background data sourced from the Ecoinvent database version 3.8. The ReCiPe 2016 Midpoint (H) and Cumulative Energy Demand (CED) methods were used for the impact assessment. The results revealed a Global Warming Potential (GWP) of 56 kg CO2 eq/kWh and a carbon payback period of 0.14 years. The energy payback period is significantly higher at 196 years, largely due to the plant’s inefficient energy capture and recurring operational failures reported. These findings highlight that although ocean wave energy is a renewable energy source, WEC’s efficiency and reliability are key factors for sustainable electricity generation. Furthermore, the findings conclude the need for selecting eco-friendly construction materials in OWC construction, namely chamber construction, and the advancement of energy-harnessing mechanisms, such as in Power Take-off (PTO) systems, to improve energy efficiency and reliability. Moreover, the importance of material recycling at the end-of-life stage, which was not accounted for in this cradle-to-gate analysis yet, is underscored for offsetting a portion of the associated environmental impacts. This research contributes novel insights into sustainable construction practices for OWC devices, offering valuable guidance for future wave energy converter designs. Full article
(This article belongs to the Section B2: Clean Energy)
Show Figures

Figure 1

29 pages, 4155 KiB  
Review
Global Meta-Analysis of Mangrove Primary Production: Implications for Carbon Cycling in Mangrove and Other Coastal Ecosystems
by Daniel M. Alongi
Forests 2025, 16(5), 747; https://doi.org/10.3390/f16050747 - 27 Apr 2025
Viewed by 1874
Abstract
Mangrove forests are among the most productive vascular plants on Earth. The gross (GPP) and aboveground forest net primary production (ANPP) correlate positively with precipitation. ANPP also correlates inversely with porewater salinity. The main drivers of the forest primary production are the porewater [...] Read more.
Mangrove forests are among the most productive vascular plants on Earth. The gross (GPP) and aboveground forest net primary production (ANPP) correlate positively with precipitation. ANPP also correlates inversely with porewater salinity. The main drivers of the forest primary production are the porewater salinity, rainfall, tidal inundation frequency, light intensity, humidity, species age and composition, temperature, nutrient availability, disturbance history, and geomorphological setting. Wood production correlates positively with temperature and rainfall, with rates comparable to tropical humid forests. Litterfall accounts for 55% of the NPP which is greater than previous estimates. The fine root production is highest in deltas and estuaries and lowest in carbonate and open-ocean settings. The GPP and NPP exhibit large methodological and regional differences, but mangroves are several times more productive than other coastal blue carbon habitats, excluding macroalgal beds. Mangroves contribute 4 to 28% of coastal blue carbon fluxes. The mean and median canopy respiration equate to 1.7 and 2.7 g C m−2 d−1, respectively, which is higher than previous estimates. Mangrove ecosystem carbon fluxes are currently in balance. However, the global mangrove GPP has increased from 2001 to 2020 and is forecast to continue increasing to at least 2100 due to the strong fertilization effect of rising atmospheric CO2 concentrations. Full article
Show Figures

Figure 1

31 pages, 4943 KiB  
Review
The Role of Artificial Intelligence in Sustainable Ocean Waste Tracking and Management: A Bibliometric Analysis
by Mariam I. Adeoba, Thanyani Pandelani, Harry Ngwangwa and Tracy Masebe
Sustainability 2025, 17(9), 3912; https://doi.org/10.3390/su17093912 - 26 Apr 2025
Viewed by 1668
Abstract
The application of artificial intelligence (AI) in monitoring and managing ocean waste reveals considerable promise for improving sustainable strategies to combat marine pollution. This study performs a bibliometric analysis to examine research trends, knowledge frameworks, and future directions in AI-driven sustainable ocean waste [...] Read more.
The application of artificial intelligence (AI) in monitoring and managing ocean waste reveals considerable promise for improving sustainable strategies to combat marine pollution. This study performs a bibliometric analysis to examine research trends, knowledge frameworks, and future directions in AI-driven sustainable ocean waste management. This study delineates key research themes, prominent journals, influential authors, and leading nations contributing to the field by analysing scientific publications from major databases. Research from citation networks, keyword analysis, and co-authorship patterns highlights significant topics such as AI algorithms for waste detection, machine learning models for predictive mapping of pollution hotspots, and the application of autonomous drones and underwater robots in real-time waste management. The findings indicate a growing global focus on utilising AI to enhance environmental monitoring, optimise waste reduction methods, and support policy development for sustainable marine ecosystems. This bibliometric study provides a comprehensive analysis of the current knowledge landscape, identifies research gaps, and underscores the importance of AI as a crucial enabler for sustainable ocean waste management, offering vital insights for researchers, industry leaders, and environmental policymakers dedicated to preserving ocean health. Full article
(This article belongs to the Section Environmental Sustainability and Applications)
Show Figures

Figure 1

29 pages, 5063 KiB  
Article
Beyond the Bloom: Invasive Seaweed Sargassum spp. as a Catalyst for Sustainable Agriculture and Blue Economy—A Multifaceted Approach to Biodegradable Films, Biostimulants, and Carbon Mitigation
by Elena Martínez-Martínez, Alexander H. Slocum, María Laura Ceballos, Paula Aponte and Andrés Guillermo Bisonó-León
Sustainability 2025, 17(8), 3498; https://doi.org/10.3390/su17083498 - 14 Apr 2025
Cited by 2 | Viewed by 2027
Abstract
The Anthropocene has ushered in unprecedented environmental challenges, with invasive seaweed blooms emerging as a critical yet understudied facet of climate change. These blooms, driven by nutrient runoff and oceanic alterations, disrupt ecosystems, threaten biodiversity, and impose economic and public health burdens on [...] Read more.
The Anthropocene has ushered in unprecedented environmental challenges, with invasive seaweed blooms emerging as a critical yet understudied facet of climate change. These blooms, driven by nutrient runoff and oceanic alterations, disrupt ecosystems, threaten biodiversity, and impose economic and public health burdens on coastal communities. However, invasive seaweeds also present an opportunity as a sustainable resource. This study explores the valorization of Sargassum spp. for agricultural applications, focusing on the development of biodegradable bioplastics and biostimulants. Field trials demonstrated the effectiveness of Marine Symbiotic® Sargassum-derived biostimulant in distinct agricultural contexts. In the Dominican Republic, trials on pepper crops showed significant improvements, including a 33.26% increase in fruit weight, a 21.94% rise in fruit set percentage, a 45% higher yield under high-stress conditions, and a 48.42% reduction in fruit rejection compared to control. In Colombia, trials across four leafy green varieties revealed biomass increases of up to 360%, a 50% reduction in synthetic input dependency, and enhanced crop coloration, improving marketability. Additionally, Sargassum-based biofilms exhibited favorable mechanical properties and biodegradability, offering a sustainable alternative to conventional agricultural plastics. Carbon credit quantification revealed that valorizing Sargassum could prevent up to 89,670 tons of CO2-equivalent emissions annually using just one Littoral Collection Module® harvesting system, while biostimulant application enhanced carbon sequestration in crops. These findings underscore the potential of invasive seaweed valorization to address multiple climate challenges, from reducing plastic pollution and GHG emissions to enhancing agricultural resilience, thereby contributing to a sustainable Blue Economy and aligning with global sustainability goals. Full article
Show Figures

Figure 1

24 pages, 18730 KiB  
Article
Comparison of Surface Current Measurement Between Compact and Square-Array Ocean Radar
by Yu-Hsuan Huang and Chia-Yan Cheng
J. Mar. Sci. Eng. 2025, 13(4), 778; https://doi.org/10.3390/jmse13040778 - 14 Apr 2025
Viewed by 515
Abstract
High-frequency (HF) ocean radars have become essential tools for monitoring surface currents, offering real-time, wide-area coverage with cost-effectiveness. This study compares the compact CODAR system (MABT, 13 MHz) and the square-array phased-array radar (KNTN, 8 MHz) deployed at Cape Maobitou, Taiwan. Radial velocity [...] Read more.
High-frequency (HF) ocean radars have become essential tools for monitoring surface currents, offering real-time, wide-area coverage with cost-effectiveness. This study compares the compact CODAR system (MABT, 13 MHz) and the square-array phased-array radar (KNTN, 8 MHz) deployed at Cape Maobitou, Taiwan. Radial velocity measurements were evaluated against data from the Global Drifter Program (GDP), and a quality control (QC) mechanism was applied to improve the data’s reliability. The results indicated that KNTN provides broader spatial coverage, whereas MABT demonstrates higher precision in radial velocity measurements. Baseline velocity comparisons between MABT and KNTN revealed a correlation coefficient of 0.77 and a root-mean-square deviation (RMSD) of 0.23 m/s, which are consistent with typical values reported in previous radar performance evaluations. Drifter-based velocity comparisons showed an initial correlation of 0.49, with an RMSD of 0.43 m/s. In more stable oceanic regions, the correlation improved to 0.81, with the RMSD decreasing to 0.24 m/s. To clarify, this study does not include multiple environmental scenarios but focuses on cases where both radar systems operated simultaneously and where surface drifter data were available within the overlapping area. Comparisons are thus limited by these spatiotemporal conditions. Radar data may still be affected by environmental or human factors, such as ionospheric variations, interference from radio frequency management issues, or inappropriate parameter settings, which could reduce the accuracy and consistency of the observations. International ocean observing programs have developed quality management procedures to enhance data reliability. In Taiwan, the Taiwan Ocean Research Institute (TORI) has established a data quality management mechanism based on international standards for data filtering, noise reduction, and outlier detection, improving the accuracy and stability of radar-derived velocity measurements.To eliminate the effects caused by different center frequencies between MABT and KNTN, this study used the same algorithms and parameter settings as much as possible in all steps, from Doppler spectra processing to radial velocity calculation, ensuring the comparability of the data. This study highlights the strengths and limitations of compact and phased-array HF radar systems based on co-observed cases under consistent operational conditions. Future research should explore multi-frequency radar integration to enhance spatial coverage and measurement precision, improving real-time coastal current monitoring and operational forecasting. Full article
(This article belongs to the Section Physical Oceanography)
Show Figures

Figure 1

27 pages, 15276 KiB  
Article
The Dynamics of Shannon Entropy in Analyzing Climate Variability for Modeling Temperature and Precipitation Uncertainty in Poland
by Bernard Twaróg
Entropy 2025, 27(4), 398; https://doi.org/10.3390/e27040398 - 8 Apr 2025
Viewed by 1054
Abstract
The aim of this study is to quantitatively analyze the long-term climate variability in Poland during the period 1901–2010, using Shannon entropy as a measure of uncertainty and complexity within the atmospheric system. The analysis is based on the premise that variations in [...] Read more.
The aim of this study is to quantitatively analyze the long-term climate variability in Poland during the period 1901–2010, using Shannon entropy as a measure of uncertainty and complexity within the atmospheric system. The analysis is based on the premise that variations in temperature and precipitation reflect the dynamic nature of the climate, understood as a nonlinear system sensitive to fluctuations. This study focuses on monthly distributions of temperature and precipitation, modeled using the bivariate Clayton copula function. A normal marginal distribution was adopted for temperature and a gamma distribution for precipitation, both validated using the Anderson–Darling test. To improve estimation accuracy, a bootstrap resampling technique and numerical integration were applied to calculate Shannon entropy at each of the 396 grid points, with a spatial resolution of 0.25° × 0.25°. The results indicate a significant increase in Shannon entropy during the summer months, particularly in July (+0.203 bits) and January (+0.221 bits), compared to the baseline period (1901–1971), suggesting a growing unpredictability of the climate. The most pronounced trend changes were identified in the years 1985–1996 (as indicated by the Pettitt test), while seasonal trends were confirmed using the Mann–Kendall test. A spatial analysis of entropy at the levels of administrative regions and catchments revealed notable regional disparities—entropy peaked in January in the West Pomeranian Voivodeship (4.919 bits) and reached its minimum in April in Greater Poland (3.753 bits). Additionally, this study examined the relationship between Shannon entropy and global climatic indicators, including the Land–Ocean Temperature Index (NASA GISTEMP) and the ENSO index (NINO3.4). Statistically significant positive correlations were observed between entropy and global temperature anomalies during both winter (ρ = 0.826) and summer (ρ = 0.650), indicating potential linkages between local climate variability and global warming trends. To explore the direction of this relationship, a Granger causality test was conducted, which did not reveal statistically significant causality between NINO3.4 and Shannon entropy (p > 0.05 for all lags tested), suggesting that the observed relationships are likely co-varying rather than causal in the Granger sense. Further phase–space analysis (with a delay of τ = 3 months) allowed for the identification of attractors characteristic of chaotic systems. The entropy trajectories revealed transitions from equilibrium states (average entropy: 4.124–4.138 bits) to highly unstable states (up to 4.768 bits), confirming an increase in the complexity of the climate system. Shannon entropy thus proves to be a valuable tool for monitoring local climatic instability and may contribute to improved risk modeling of droughts and floods in the context of climate change in Poland. Full article
(This article belongs to the Special Issue 25 Years of Sample Entropy)
Show Figures

Figure 1

21 pages, 12701 KiB  
Article
An Overview of Air-Sea Heat Flux Products and CMIP6 HighResMIP Models in the Southern Ocean
by Regiane Moura, Fernanda Casagrande and Ronald Buss de Souza
Atmosphere 2025, 16(4), 402; https://doi.org/10.3390/atmos16040402 - 30 Mar 2025
Cited by 1 | Viewed by 854
Abstract
The Southern Ocean (SO) is crucial for global climate regulation by absorbing excess heat and anthropogenic CO2. However, representing air-sea heat fluxes in climate models remains a challenge, particularly in regions characterised by strong ocean–atmosphere–sea ice interactions. This study analysed air–sea [...] Read more.
The Southern Ocean (SO) is crucial for global climate regulation by absorbing excess heat and anthropogenic CO2. However, representing air-sea heat fluxes in climate models remains a challenge, particularly in regions characterised by strong ocean–atmosphere–sea ice interactions. This study analysed air–sea heat fluxes over the SO using four products and seven CMIP6 HighResMIP pairs, comparing the mean state and trends (1985–2014) of sensible and latent heat fluxes (SHF and LHF, respectively) and the impact of grid resolution refinement on their estimation. Our results revealed significant discrepancies across datasets and SO sectors, with LHF showing more consistent seasonal performance than SHF. High-resolution models better capture air–sea heat flux variability, particularly in eddy-rich regions, with climatological mean differences reaching ±20 W.m−2 and air–sea exchange variations spreading up to 30%. Most refined models exhibited enhanced spatial detail, amplifying trend magnitudes by 30–50%, with even higher values observed in some regions. Furthermore, the trend analysis showed significant regional differences, particularly in the Pacific sector, where air–sea heat fluxes showed heightened variability. Despite modelling advances, discrepancies between datasets revealed uncertainties in climate simulations, highlighting the critical need for continued improvements in climate modelling and observational strategies to accurately represent SO air–sea heat fluxes. Full article
Show Figures

Figure 1

25 pages, 7863 KiB  
Article
Assessment of the Impacts of Different Carbon Sources and Sinks on Atmospheric CO2 Concentrations Based on GEOS-Chem
by Ge Qu, Jia Zhou, Yusheng Shi, Yongliang Yang, Mengqian Su, Wen Wu and Zhitao Zhou
Remote Sens. 2025, 17(6), 1009; https://doi.org/10.3390/rs17061009 - 13 Mar 2025
Cited by 1 | Viewed by 1204
Abstract
Global atmospheric CO2 concentrations, driven by anthropogenic emissions and natural carbon cycle dynamics, have emerged as a critical accelerator of climate change. However, due to the spatiotemporal heterogeneity of carbon sources and sinks, estimating CO2 flux remains highly uncertain. Accurately quantifying [...] Read more.
Global atmospheric CO2 concentrations, driven by anthropogenic emissions and natural carbon cycle dynamics, have emerged as a critical accelerator of climate change. However, due to the spatiotemporal heterogeneity of carbon sources and sinks, estimating CO2 flux remains highly uncertain. Accurately quantifying the contribution of various carbon sources and sinks to atmospheric CO2 concentration is essential for understanding the carbon cycle and global carbon balance. In this study, GEOS-Chem (version 13.2.1), driven by MERRA-2 meteorological data, was used to simulate monthly global CO2 concentrations from 2006 to 2010. The model was configured with a horizontal resolution of 2.5° longitude × 2.0° latitude and 47 vertical hybrid-sigma layers up to 0.01 hPa. To evaluate the impact of different emission sources and sinks, the “Inventory switching and replacing” approach was applied, designing a series of numerical experiments in which individual emission sources were selectively disabled. The contributions of eight major CO2 flux components, including fossil fuel combustion, biomass burning, balanced biosphere, net land exchange, aviation, shipping, ocean exchange, and chemical sources, were quantified by comparing the baseline simulation (BASE) with source-specific perturbation experiments (no_X). The results show that global CO2 concentration exhibits a spatial pattern with higher concentrations in the Northern Hemisphere and land areas, with East Asia, Southeast Asia, and eastern North America being high-concentration regions. The global average CO2 concentration increased by 1.8 ppm year−1 from 2006 to 2010, with China’s eastern region experiencing the highest growth rate of 3.0 ppm year−1. Fossil fuel combustion is identified as the largest CO2 emission source, followed by biomass burning, while oceans and land serve as significant CO2 sinks. The impact of carbon flux on atmospheric CO2 concentration is primarily determined by the spatial distribution of emissions, with higher flux intensities in industrialized and biomass-burning regions leading to more pronounced local concentration increases. Conversely, areas with strong carbon sinks, such as forests and oceans, exhibit lower net CO2 accumulation. Full article
Show Figures

Figure 1

19 pages, 15754 KiB  
Article
Time Lag Analysis of Atmospheric CO2 and Proxy-Based Climate Stacks on Global–Hemispheric Scales in the Last Deglaciation
by Zhi Liu and Xingxing Liu
Quaternary 2025, 8(1), 11; https://doi.org/10.3390/quat8010011 - 18 Feb 2025
Viewed by 1095
Abstract
Based on 88 well-dated and high-resolution paleoclimate records, global and hemispheric stacks of the last deglacial climate were synthesized by utilizing the normalized average method. A sequential relationship between the West Antarctic Ice Sheet Divide ice core CO2 concentration and the composited [...] Read more.
Based on 88 well-dated and high-resolution paleoclimate records, global and hemispheric stacks of the last deglacial climate were synthesized by utilizing the normalized average method. A sequential relationship between the West Antarctic Ice Sheet Divide ice core CO2 concentration and the composited proxy-based global–hemispheric climate stacks was detected using the Wilcoxon rank-sum test and wavelet analysis. The results indicate that the climate stack of the Northern Hemisphere started to increase slowly before 22 kabp, possibly due to the enhancement of summer insolation at high northern latitudes, the onset of warming in the Southern Hemisphere occurred around 19 kabp, and the atmospheric CO2 concentration began to raise around 18.1 kabp. This suggests that the change in northern high-latitude summer insolation was the initial trigger of the last deglaciation, and atmospheric CO2 concentration was an internal feedback associated with global ocean circulation in the Earth’s system. Both the Wilcoxon rank-sum test and wavelet analysis showed that during the BØlling–AllerØd and the Younger Dryas periods there was no obvious asynchrony between the global climate and atmospheric CO2 concentration, which perhaps implies a fast feedback–response mechanism. The seesawing changes in interhemispheric climate and the abrupt variations in the atmospheric CO2 concentration could be explained by the influences of Atlantic meridional overturning circulation strength during the BØlling–AllerØd and the Younger Dryas periods. This reveals that Atlantic meridional overturning circulation played an important role in the course of the last deglaciation. Full article
Show Figures

Figure 1

28 pages, 9216 KiB  
Review
Current Status and Reflections on Ocean CO2 Sequestration: A Review
by Shanling Zhang, Sheng Jiang, Hongda Li, Peiran Li, Xiuping Zhong, Chen Chen, Guigang Tu, Xiang Liu and Zhenhua Xu
Energies 2025, 18(4), 942; https://doi.org/10.3390/en18040942 - 16 Feb 2025
Viewed by 1255
Abstract
Climate change has become one of the most pressing global challenges, with greenhouse gas emissions, particularly carbon dioxide (CO2), being the primary drivers of global warming. To effectively address climate change, reducing carbon emissions has become an urgent task for countries [...] Read more.
Climate change has become one of the most pressing global challenges, with greenhouse gas emissions, particularly carbon dioxide (CO2), being the primary drivers of global warming. To effectively address climate change, reducing carbon emissions has become an urgent task for countries worldwide. Carbon capture, utilization, and storage (CCUS) technologies are regarded as crucial measures to combat climate change, among which ocean CO2 sequestration has emerged as a promising approach. Recent reports from the International Energy Agency (IEA) indicate that by 2060, CCUS technologies could contribute up to 14% of global cumulative carbon reductions, highlighting their significant potential in mitigating climate change. This review discusses the main technological pathways for ocean CO2 sequestration, including oceanic water column sequestration, CO2 oil and gas/coal seam geological sequestration, saline aquifer sequestration, and seabed methane hydrate sequestration. The current research status and challenges of these technologies are reviewed, with a particular focus on the potential of seabed methane hydrate sequestration, which offers a storage density of approximately 0.5 to 1.0 Gt per cubic kilometer of hydrate. This article delves into the formation mechanisms, stability conditions, and storage advantages of CO2 hydrates. CO2 sequestration via hydrates not only offers high storage density but also ensures long-term stability in the low-temperature, high-pressure conditions of the seabed, minimizing leakage risks. This makes it one of the most promising ocean CO2 sequestration technologies. This paper also analyzes the difficulties faced by ocean CO2 sequestration technologies, such as the kinetic limitations of hydrate formation and leakage monitoring during the sequestration process. Finally, this paper looks ahead to the future development of ocean CO2 sequestration technologies, providing theoretical support and practical guidance for optimizing their application and promoting a low-carbon economy. Full article
(This article belongs to the Section H: Geo-Energy)
Show Figures

Figure 1

Back to TopTop