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It is hard not to consider sea-level rise as reflective of an imminent crisis. Drawing together insights from Black feminism and Indigenous thought from the Island Pacific, this article counters a discourse of crisis without uncritically accepting the "oceanifying" of the planet. It moves between analyses of poetic, visual, and plant cultivation practices to show that there is a rubric for living and thinking with the ocean that emphasizes how human and nonhuman life can "become-with" each other in response to ecological degradation while still grappling with the lived legacies of colonial pasts. These oceanic coordinations are ways of knowing that destabilize human exceptionalism from the outset while not excluding the human entirely. Rather, these frameworks incorporate human-nonhuman relations to expand our frame of reference, challenging dominant anthropocentric narratives of crisis and helping imagine and live within oceanic futures. [ABSTRACT FROM AUTHOR]

The spot (Leistomus xanthurus) is among the most abundant demersal fish species in the estuaries of the Atlantic and Gulf coasts of the United States and in the coastal ocean. [...]

When it comes to telling ocean conservation stories, science provides the foundation, but photography brings them to life. That's the perspective that conservationist and award-winning photographer Henley Spiers brings to [...]

It has previously been shown that trends in sensible heat from climate models have had a substantial contribution to global precipitation changes. We illustrate that this is the case also in the most recent Coupled Model Intercomparison Project Phase 6 (CMIP6). However, we find that over the period since 1980 reanalyses do not support the reduction in sensible heat from the CMIP6 models and rather estimate a global increase in sensible heat which would contribute to a precipitation reduction. Satellite data over a period of two decades over global ocean generally show an opposite sign of the sensible heat trend to the CMIP6 models, similarly to the reanalyses. [ABSTRACT FROM AUTHOR]

Visible and microwave satellite measurements can provide the global whitecap fraction. The bubble clouds are three-dimensional structures, and a space-based lidar can provide complementary observations of the bubble depth. Here, we use lidar measurements of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite to quantify global bubble depth from the depolarization. The relationship between CALIPSO bubble depth and wind speed from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and AMSR2 is similar to a recently derived relationship based on buoy measurements. The CALIPSO-based bubble depth data show global distributions and seasonal variations consistent with the high wind speed (> 7 m/s) but with some variance. We also found similarities between the CALIPSO bubble depth and the whitecap fraction from AMSR2 and WindSat. Our findings support the use of spaceborne lidar measurements for advancing the understanding of the 3D bubble properties, and the ocean physics at high wind speeds. [ABSTRACT FROM AUTHOR]

Marine biological nitrogen fixation (BNF) is crucial for introducing "new nitrogen" into the oceans. Over the past 30 years, numerous laboratory and on-board culture experiments have been conducted studying the effects of nutrients such as total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), and dissolved iron (DFe) on marine diazotrophs such as Braarudosphaera bigelowii (B. bigelowii), Trichodesmium, Crocosphaera and noncyanobacterial diazotrophs (NCDs). Most studies concluded that elevated dissolved inorganic nitrogen levels inhibit nitrogen fixation in Trichodesmium, promote its growth, and have minimal effect on B. bigelowii. The impact on NCDs is unclear. Moreover, elevated dissolved inorganic phosphorus (DIP) levels can promote individual growth, population growth, and nitrogen fixation in most diazotrophs in P-limited marine environments. Dissolved organic phosphorus is a potential phosphorous source for diazotrophs in low-DIP environments. Elevated DFe can promote population growth and nitrogen fixation in diazotrophs in Fe-limited marine environments. At present, most diazotrophs have yet to achieve pure culture. Moreover, the effect of nutrients on diazotrophs is mainly limited to the study of a single nutrient, which cannot accurately reflect the actual Marine environment where diazotrophs live. As a result, our understanding of the effect of nutrients on diazotrophs is still insufficient. Future research focusing on the issues above and the development of innovative technologies and methodologies to investigate the impact of marine BNF is highly recommended, which will allow for a more precise assessment of the impact of marine BNF on global primary productivity while providing a scientific foundation for rational evaluation of ocean CO2 uptake and emissions. [ABSTRACT FROM AUTHOR]

The Challenger Deep (CD) is the deepest known hadal trench in the world. Due to challenges in data sampling at extreme ocean depths, the Lower Circumpolar Deep Water (LCDW) transport and ocean circulation structure in the CD remain unclear. By analyzing data from an extra-deep current meter mooring array, here we find a three-layer circulation in the CD, transitioning downward from westward LCDW flow (about −1.866 ± 2.953 Sv, 1 Sv = 106 m3/s) to cyclonic circulation, and then to anticyclonic circulation. The westward flow reverses its direction during summer, giving evidence for bidirectional connectivity of deep-sea basins, while the cyclonic-anticyclonic circulation is relatively steady. The LCDW intrusion, local topography and turbulent mixing are crucial for modulating the three-layer circulation. Turbulent mixing plays a key role in driving the anticyclonic circulation. Our findings provide insights for understanding the hydrodynamic environment in the ocean's deepest areas. The study presents data from moorings in the Challenger Deep, the deepest known hadal trench in the world, showing a three-layer circulation structure, modulated by deep-water intrusion, topography and turbulent mixing. [ABSTRACT FROM AUTHOR]

Southern Hemisphere (SH) storminess has increased in the satellite era and recent work suggests comprehensive climate models significantly underestimate the trend. Here, we revisit this reanalysis-model trend discrepancy to better understand the mechanisms underlie it. A comprehensive like-for-like analysis shows reanalysis trends exhibit large uncertainty, and coupled climate model simulations exhibit weaker trends than most but not all reanalyses. However, simulations with prescribed sea surface temperature (SST) exhibit significantly greater storminess trends, particularly in the South Pacific, implying SST trend discrepancies in coupled simulations impact storminess trends. Using pacemaker simulations that correct Southern Ocean and tropical east Pacific SST trend discrepancies, we show that storminess trends in coupled simulations are underestimated because they do not capture the enhanced storminess resulting from Southern Ocean cooling and La-Nina-like teleconnection trends. Our findings emphasize large reanalysis uncertainty in SH circulation trends and the impact of regional SST trend discrepancies on circulation trends. [ABSTRACT FROM AUTHOR]

Arctic sea-ice extent has strongly decreased since the beginning of satellite observations in the late 1970s. While several drivers are known to be implicated, their respective contribution is not fully understood. Here, we apply the Liang-Kleeman information flow method to five different large ensembles from the Coupled Model Intercomparison Project Phase 6 (CMIP6) over the 1970-2060 period to investigate the extent to which fluctuations in winter sea-ice volume, air temperature and ocean heat transport drive changes in subsequent summer Arctic sea-ice extent. This allows us to go beyond classical correlation analyses. Results show that air temperature is the most important controlling factor of summer sea-ice extent at interannual time scale, and that winter sea-ice volume and Atlantic Ocean heat transport play a secondary role. If we replace air temperature by net shortwave and downward longwave radiations, we find that the sum of influences from both radiations is almost similar to the air temperature influence, with the longwave radiation being dominant in driving changes in summer sea-ice extent. Finally, we find that the influence of air temperature is more prominent during periods of large sea-ice reduction and that this temperature influence has overall increased since 1970. [ABSTRACT FROM AUTHOR]

This study presents the water column temperature data collected during several cruises on board the Italica, Araon and Laura Bassi research vessels, in the framework of the Climatic Long-term Interaction for the Mass balance in Antarctica (CLIMA), Southern Ocean Chokepoints Italian Contribution (SOChIC), and Marine Observatory of the Ross Sea (MORSea) projects, funded by the Italian National Antarctic Research Program (PNRA). Data were collected between New Zealand and the Ross Sea during the austral summers from 1994/1995 to 2023/2024. Across this chokepoint of the Antarctic Circumpolar Current, XBT Sippican T7 probes were launched with a regular 20 km sampling, providing temperature profiles with a vertical resolution of 65 cm and a maximum nominal depth of 760 m. All temperature profiles underwent a rigorous quality control, including a general malfunctioning verification, the removal of spikes, the consistency check of adjacent profiles, the comparison to regional oceanographic features and satellite altimetry observations, and a final visual check by operator. Data quality checks led us to discard about 12 % of acquired XBT measurements. This dataset contributes to the improvement of our understanding of Southern Ocean features, being highly valuable for studies focusing on climate variability, especially across the Antarctic Circumpolar Current and its fronts. Furthermore, we expect that the collected XBT data will serve as a useful tool for the calibration and validation of recent satellite observations and for the improvement of Southern Ocean oceanographic simulations. [ABSTRACT FROM AUTHOR]

Palisada corallopsis has a widely reported distribution in the western and eastern Atlantic and some areas of the Indo-Pacific Ocean, whereas P. furcata has a more restricted distribution, reported only from Brazil and Cuba. Palisada corallopsis and P. furcata were collected from their type localities, Havana, Cuba and Ceará, Brazil, respectively, and compared by morphological and molecular analyses using rbcL and COI-5P genes. The molecular results placed the sequences from the type locality of both species in the same clade, showing low genetic divergence, 0.95 % for rbcL and 1.6 % for COI-5P. Morphologically, the species share similar habits, with branchlets bi-to trifurcated, cortical cells that may be arranged as a palisade and connected by secondary pit-connections. Our detailed morphological observations, including examination of the type specimens, and molecular analyses demonstrate that P. corallopsis and P. furcata are conspecific, P. furcata being a later taxonomic synonym of P. corallopsis. [ABSTRACT FROM AUTHOR]

On 15 January 2022, a massive underwater eruption occurred at the Hunga Tonga‐Hunga Ha'apai Volcano. The plume reached the mesosphere, and the eruption excited a significant atmospheric Lamb wave, which forced the tsunami. The complicated tsunami waveforms due to ocean‐atmosphere coupling prevented inferring the force history of the excitation. To address this, we analyze ocean surface gravity waves (OSWs) from 15 to 40 mHz, which are decoupled from the Lamb wave due to their slower phase velocities. Modeling these OSWs, we infer that the excitation started at 4:00 UTC with an amplitude of 1010 $1{0}^{10}$ N and lasted for 5 hr, followed by a sub‐event at 8:40 UTC. The observations suggest an initial blowout of seawater above the summit and a subsequent outflow that excited a tsunami below 5 mHz. The 2 hr delayed OSW excitation from 6 to 15 mHz may indicate seawater inflow into the crater. Plain Language Summary: On 15 January 2022, the Hunga Tonga‐Hunga Ha'apai volcano experienced a massive underwater eruption. This eruption sent a plume into the atmosphere and produced a powerful atmospheric wave that caused an early arrival of the tsunami. The complex tsunami propagation coupled with the atmospheric wave prevents us from understanding the excitation processes. To address this, we focussed on ocean surface gravity waves (OSWs) in an oscillatory period from 25 to 67 s, also interpreted as short‐period tsunamis. These OSWs are less affected by these atmospheric waves because of the slow propagation speed. Because the OSWs are less influenced by ocean depth, they are easier to model. The observed OSWs show that the eruption started at 4:00 UTC with a vertical force of approximately 1010 $1{0}^{10}$ N and continued for about 5 hr. Another significant sub‐event occurred around 8:40 UTC. Furthermore, the OSWs in an oscillatory period from 67 to 167 s arrived about 2 hr after the short‐period OSWs. These observations suggest that the eruption blew seawater above the volcano's summit and a subsequent outflow that excited a tsunami. The 2 hr delay in low‐frequency OSW could indicate that seawater flowed into the crater. Key Points: Ocean surface gravity waves at 15–40 mHz were excited at 4:00 UTC when an underwater eruption occurred at Hunga Tonga‐Hunga Ha'apai VolcanoA significant sub‐event at about 8:40 UTC followed the main event, and the ocean surface gravity waves lasted for half a dayThe observations of ocean surface gravity waves suggest a blowout of seawater above the summit and the inflow of seawater into the crater [ABSTRACT FROM AUTHOR]

Unlike prior researches focusing on interannual or interdecadal changes of the Northwest Pacific subtropical high (NWPSH), this paper emphasizes the interdecadal changes in the relationship between May‐June and July‐August NWPSH. The correlation coefficients between them are 0.66 (passing the 99.9% confidence level) and 0.12 during 1979–2002 and 2003–2023. Therefore, the May‐June NWPSH has a strong connection with July‐August East Asian precipitation during 1979–2002, but not during 2003–2023. The interdecadal variations in the relationship of NWPSH are due to interdecadal changes of ENSO. During 1979–2002, the eastern‐type ENSO in prior winter, having longer durations, can influence May‐June and July‐August NWPSH and the North Indian Ocean. However, the central‐type ENSO in prior winter only persists it's influence until May‐June, and changes into a Pacific Dipole pattern in July‐August during 2003–2023. Despite the North Indian Ocean continually warms during 2003–2023, the tropical Pacific Dipole offsets its impacts on the NWPSH. Plain Language Summary: The Northwest Pacific Subtropical High (NWPSH) has always been valued by meteorologists due to its important role in the East Asian climate. This paper found that the relationship between the NWPSH in May‐June and July‐August has weakened significantly since 2002. The eastern‐type ENSO, characterized by longer durations, can influence the NWPSH and the North Indian Ocean in May‐June and July‐August before 2002. However, from 2003 to 2023, the influence of the central‐type ENSO only persists until May‐June, transitioning to a Pacific Dipole pattern in July‐August. Therefore, both May‐June and July‐August NWPSH are affected by the North Indian Ocean before 2002. However, the NWPSH in May‐June is affected by the North Indian Ocean and prior winter ENSO after 2002, while the July‐August NWPSH is impacted by the tropical Pacific Dipole. And the tropical Pacific Dipole also offsets the influence of the North Indian Ocean on the NWPSH. This leads to a weakening of the relationship between the NWPSH in May‐June and July‐August. Key Points: The relationship between the Northwest Pacific subtropical high (NWPSH) in May‐June and July‐August has significantly weakened after 2002The reason for weakening relationship of NWPSH is that the persistent eastern ENSO has become a short‐period central ENSO after 2002Central ENSO will become Pacific Dipole mode in summer, which will weaken the influence of North Indian Ocean on NWPSH [ABSTRACT FROM AUTHOR]

The Indonesian Throughflow (ITF) thermocline, as exclusive water source for the "warm water route" of the Atlantic Meridional Overturning Circulation (AMOC), provides waters that exit the Indian Ocean and join the AMOC upper limb via the Agulhas Leakage (AL). Hence, investigating long‐term variations in the ITF thermocline and its implications on the AL is important for understanding dynamics of the AMOC. Here, the thermohaline history of the ITF thermocline was reconstructed for the last ∼410 kyr based on δ18O and Mg/Ca of planktonic foraminifera from International Ocean Discovery Program Site U1483. By integrating the new and published records, we found that precession drives variation of the ITF thermocline through modulating the intensity of the Australian‐Indonesian winter monsoon, El Niño‐Southern Oscillation‐like states and formation of the North Pacific Tropical Water, in turn exerting a transoceanic influence on the amount of the AL and seawater temperature and salinity of the South Atlantic thermocline. Plain Language Summary: It is widely acknowledged that the Indonesian Throughflow (ITF), a key component of the global thermohaline circulation, plays an important role in the global climate and ocean circulation. However, in contrast to concentrating on the factors that shaped the ITF in the geological history, few studies considered the ITF as a factor to influence climate and ocean circulation, especially on long timescales. In this study, we utilized shell δ18O and Mg/Ca of a planktonic foraminiferal thermocline‐dwelling species from the Timor Sea, the main outflow passage of the ITF, to reconstruct the temperature and salinity changes of the ITF thermocline during the past ∼410 kyr. By integrating the new and published paleo‐oceanographic and ‐climatological records, we found that the ∼20‐kyr wobbles of the Earth's axis (precession) induced variations in the flow strength and seawater temperature and salinity of the ITF thermocline, and in turn regulated the amount of the Agulhas Leakage and seawater temperature and salinity of the South Atlantic thermocline. Our results underscore the essential role of the ITF in the connectivity among the oceans. Key Points: Precession drove variations in the ITF thermocline by modulating the intensity of the Australian‐Indonesian winter monsoon, ENSO‐like states and formation of the North Pacific Tropical WaterVariations in the ITF thermocline regulated the amount of AL and seawater temperature and salinity of South Atlantic thermocline [ABSTRACT FROM AUTHOR]

The three‐dimensional structure of the Tropical Cyclone's baroclinic wake is synthesized as an averaged baroclinic‐dominant response of the upper ocean. The resulting persisting sea surface depression can easily be monitored using the present‐day altimeter constellation. Following a semi‐empirical framework, these baroclinic wake signatures are linked to the inner core TC dynamic and the ocean stratification. To collect these fine‐scale parameters, spaceborne SAR instruments and Argo fleet are used, to precisely capture the maximum wind region and the irregularities of the ocean vertical structure. This combination of high‐resolution information is found paramount to fully capture the modulation of sea surface height anomalies, and its mean trend, especially for major hurricanes. Baroclinic signatures mostly range around 10–20 cm and peak at 40 cm. Deeper anomalies correspond to barotropic response, removed from the present analysis. Plain Language Summary: In the wakes of Tropical Cyclones (TCs), sea surface depressions of about 10 cm appear. These TC signatures are persistent enough to be easily monitored by the current fleet of altimeter instruments. A measured sea surface height anomaly integrates and reduces the air/sea interactions during the TC passage into a single observable metric. It mostly encodes the cyclonic wind forcing and the interior ocean state. A broad constellation of remote sensing and in‐situ instruments has been gathered to compile 200 cyclonic episodes, collecting a wide range of TC sizes, intensities, and translation speeds together with oceanic conditions. A synthetic relationship is found to robustly predict most observed sea surface height anomalies. Moreover, when high‐resolution information is available to estimate the ocean interior state and the TC radius of maximum winds. Such a diagnostic thus explains the dominant baroclinic ocean response to a TC passage, and, inversely, can be used to infer ocean stratification or forcing parameters in the absence of high‐resolution observations. Key Points: Residual sea surface height anomalies from the cold wakes of Tropical Cyclones are analyzed using a multi‐modal approach at global scaleA scaling law provides a robust interpretation of the baroclinic response to given ocean stratification and forcing conditionsHigh resolution measurements are found critical to correctly anticipate the SSHA amplitudes with localized pre‐storm ocean stratification [ABSTRACT FROM AUTHOR]

The convergence analysis for least-squares finite element methods led to various adaptive mesh-refinement strategies: Collective marking algorithms driven by the built-in a posteriori error estimator or an alternative explicit residual-based error estimator as well as a separate marking strategy based on the alternative error estimator and an optimal data approximation algorithm. This paper reviews and discusses available convergence results. In addition, all three strategies are investigated empirically for a set of benchmarks examples of second-order elliptic partial differential equations in two spatial dimensions. Particular interest is on the choice of the marking and refinement parameters and the approximation of the given data. The numerical experiments are reproducible using the author's software package octAFEM available on the platform Code Ocean. [ABSTRACT FROM AUTHOR]

The Argo array of profiling floats has considerably increased the observing capability of the three-dimensional global ocean and the knowledge of the ocean response to climate change. In particular, the Argo sampling has allowed observing relevant ocean indicators over the whole Mediterranean Sea especially during the last decade. In this study, the Mediterranean Argo network is comprehensively described from its spatio-temporal coverage to its capability to observe ocean monitoring indicators at sub-regional scale. For this purpose, the Argo array, as a non-interpolated product of profiles, is used to estimate the ocean heat and salt contents integrated within the upper, intermediate and deep layers over the period 2013-2022 in the different sub-regions of the basin. The same computational method is also applied to a model reanalysis product to estimate the impact of sampling of the sole Argo array. The sampling error is defined at sub-regional scale by comparing estimations from the whole model grid (full-sampled model) and from the Argo-like sampled model grid (subsampled model). Warming and salinification trends are well captured by the Argo array over the period of study, warming trends being the highest in the subregions of the western Mediterranean Sea from surface to depth and salinification trends being higher in the eastern sub-basin for the upper layer and in the western sub-basin for the deeper layers. This study also demonstrates the capability of the Argo array to capture local ocean structures and dynamics (e.g. anticyclonic and cyclonic gyres, intermediate and deep convection events and Atlantic Water inflows) and to account for their impact in the sub-regional variability of ocean heat and salt contents in the upper, intermediate and deep layers from seasonal to interannual scales. Considering these structures is fundamental for the understanding of the thermohaline circulation and changes observed in the Mediterranean Sea, and thus for future climate studies. [ABSTRACT FROM AUTHOR]

An observation operator in data assimilation was formalized based on the signatures extracted from the integral quantities contained within observed vertical profiles in the ocean. A four-dimensional variational global ocean data assimilation system, founded on this observation operator, was developed and utilized to conduct preliminary data assimilation experiments over a ten-year assimilation window, comparing the proposed method, namely profile-by-profile matching, with the traditional method, namely point-by-point matching. The proposed method not only demonstrated a point-by-point skill comparable to the traditional method but also provided superior analysis fields in terms of profile shapes on the temperature-salinity plane. This is an indication of a well-balanced analysis field, in contrast to the traditional method, which can produce extremely poor relative errors for certain metrics. Additionally, signatures were shown to successfully represent properties of the water column, such as steric height, and serve as an effective new diagnostic tool. The top-down, or macro--micro, viewpoint in this method is fundamental to the extent that it can offer an alternative view of how we comprehend ocean observations, holding significant implications for the advancement of data assimilation. [ABSTRACT FROM AUTHOR]

Understanding the impacts of the Indonesian Throughflow (ITF) on the eastward propagation of the Madden-Julian Oscillation (MJO) is crucial for accurately simulating the MJO and achieving high-skill sub-seasonal predictions. Our analyses demonstrate a significant enhancement of MJO eastward propagation due to the strong ITF. Blocking the ITF decreases the eastward sea surface temperature (SST) gradient over the tropical Indian Ocean, hindering MJO propagation across the Maritime Continent (MC). Removing the MJO circulation-induced intraseasonal variability of the ITF transport also weakens the eastward propagation of the MJO, as the MJO easterly winds enhance the ITF transport and warm the eastern tropical Indian Ocean. These experiments reveal that mean and intraseasonal variability of the ITF transport contribute to 73% and 42% of the eastward propagation of the MJO over the MC, respectively. The findings presented in this study highlight the significant role of the ITF in shaping the propagation of the MJO. [ABSTRACT FROM AUTHOR]

Skin photoaging, caused by prolonged exposure to ultraviolet (UV) radiation, manifests as intricate biological transformations, encompassing oxidative damage and structural alterations. Despite a growing need for effective interventions, the existing therapeutic repertoire for treating skin photoaging remains constrained. Recent investigations have shifted focus towards the application of hydrogels as a novel avenue for addressing this concern. Various active substances can be combined with hydrogels for transdermal delivery, including compounds from the ocean, plants, cell active substances, which can promote skin UV damage repair mainly through antioxidant, antiinflammatory and promote collagen production. This review seeks to offer a thorough summary of recent progress in employing hydrogels for addressing skin photoaging. Topics covered include the mechanism of skin photoaging, and emerging trends in hydrogel-based therapies for skin rejuvenation. The discussion also explores challenges and outlines potential future directions in leveraging hydrogels as therapeutic agents to address skin photoaging. [ABSTRACT FROM AUTHOR]

Polar sea surface height observation by radar altimeters requires missions with high-latitude orbit and specific processing to observe the sea-ice-covered region within fractures in the ice. Here, we combine sea surface height estimates from different radar satellites over the ice-free and ice-covered polar oceans to create cross-calibrated along-tracks and gridded products over the Arctic Ocean (2011-2021) and the Southern Ocean (2013-2021). The sea surface height from our regional polar products is in great agreement with tide gauges and bottom pressure recorders at monthly timescales in seasonally to year-round icecovered regions. Thanks to the use of several missions and the mapping strategy, our multi-mission products have a greater resolution than monomission products. Part of the sea level variability of the Arctic Ocean product is related to the Arctic Oscillation atmospheric circulation. At long term, the Arctic altimetry sea level is coherent with in-situ steric height evolution in the Beaufort gyre, and negative sea level trends over the 10-year period are observed in the East Siberian slope region, which may be related to the local freshwater decrease observed by other studies. Our regional polar sea level products are limited by current understanding of the sea-ice lead measurements, and homogenization of these polar products with global sea level products needs to be tackled. [ABSTRACT FROM AUTHOR]

The East African March–April–May (MAM, "long rains") precipitation decline in recent decades remains a puzzle marked by various proposed large‐scale drivers. Here, the interannual variability of the long rains and their recent drying trend are examined using global model simulations and observations. Comparison of a control simulation and re‐initialized simulations in which land‐surface feedback is suppressed shows that much of the long rains deficit experienced between 1980 and 2014 is synchronized with the warming of the Northwestern Eurasian landmass. In agreement with the modeling results, multiple observational data sets reveal a strong negative correlation between MAM mean East African rainfall amount and the surface temperature over Northwestern Eurasia. Idealized simulations further indicate that warming in Northwestern Eurasia weakens the regional Hadley Cell and diverts the monsoonal transport of moisture away from Eastern Africa toward Europe and southern Africa, highlighting the role of remote land surface warming on the observed precipitation decline. Plain Language Summary: In this article the inter‐annual variability and the observed long‐term decline of Boreal spring rainfall over Eastern Africa are examined. Previous research on the causes of these droughts focused on sea surface temperature variability over tropical oceans. In this work through extensive analysis of observations and global modeling we show that land‐surface feedbacks over Northwestern Eurasia are the primary culprit. More broadly the work highlights the importance of teleconnections between regional climates through remote impacts of land surface feedbacks. Key Points: We demonstrate a co‐variability of East African March–April–May rainfall (long rains) and surface temperature over Northwestern EurasiaAnalysis of model simulations show warming Northwestern Eurasia weakens the local Hadley cell and introduces subsidence over East AfricaThe observed decline in East African March–April–May rainfall observed during 1980–2014 can be explained by this warming [ABSTRACT FROM AUTHOR]

Atmospheric rivers (ARs) are key agents in distributing extratropical precipitation and transporting moisture poleward. Climate models forced by historical anthropogenic forcing suggest an increase in AR activity in the extratropics over the past four decades. However, reanalyses indicate a ~6° to 10° poleward shift of ARs during boreal winter in both hemispheres, featuring a rise along 50°N and 50°S and a decrease along 30°N and 30°S. Our analysis demonstrates that low-frequency sea surface temperature variability in the tropical eastern Pacific exhibits a cooling tendency since 2000 that plays a key role in driving this global AR shift, mostly over extratropical oceans, through a tropical-driven eddy-mean flow feedback. This mechanism also operates on interannual timescales, controlled by the El Niño-Southern Oscillation, and is less pronounced over the Southern Ocean due to weaker eddy activity during austral summer. These highlight the sensitivity of ARs to large-scale circulation changes driven by both internal variability and external forcing in current and upcoming decades. [ABSTRACT FROM AUTHOR]

Starting in 1969, small groups of West Papuans have occasionally crossed the Torres Strait to Australia and sought its protection. In public discourse, these arrivals have figured as part of a narrative about Australia’s relationship with Indonesia. By contrast, in the public discourse about border control, which focuses on attempted travel across the Indian Ocean and distinct ‘waves’, they have been treated as a footnote, at most. In this article, we closely examine the Australian government’s response to West Papuan ‘boat people’ over time to demonstrate that, unlike in public discourse, border control considerations have loomed large in the government’s response. We argue that, in order to understand Australia’s approach to border control, we should see West Papuan asylum seekers in the context of border control policy and not only as a problem in Australia’s relationship with Indonesia. [ABSTRACT FROM AUTHOR]

AbstractThis paper shows how and why it is ‘im-possible’—i.e. simultaneously possible and impossible—for humans to travel and stay underwater by narrating the story of how Jules’ Undersea Lodge was designed and how its guests can remain there for relatively long periods of time. Drawing from interviews with its designer, Ian Koblick, reflexive ethnographic material collected at Key Largo’s (Florida) Jules’ Undersea Lodge in the early spring of 2024, and an interview with Joseph Dituri—who in 2023 set a world record for the longest time spent in an underwater habitat – we conceptualize im-possibility as a dialectical tension between possibility and impossibility. [ABSTRACT FROM AUTHOR]

Atlantic bluefin tuna (ABFT; Thunnus thynnus) is a highly migratory species. To investigate the migrations and vertical behaviours of ABFT migrating to Nordic waters, we deployed pop-up satellite archival transmitting tags on 25 ABFT off Norway (curved fork length: 228–292 cm). We obtained 16 full-year migrations, which differed between individuals, and physically recovered 13 tags, which provided 4699 days of archival depth and temperature data. ABFT occupied waters from the Arctic Circle to as far south as Cabo Verde, Africa, and occupied depths down to 1190 m and temperatures from 0.5 to 27.8°C. During their annual migrations, ABFT spent, on average, 68 days in Norwegian waters, 65 days in the Newfoundland Basin, 35 days around the Canary Islands and 33 days in the West European Basin. Most ABFT entered the Mediterranean Sea with a mean entry date of 13 May and visited known spawning grounds, staying, on average, 44 days. All ABFT with full-year deployments returned to Norwegian waters. ABFT displayed high site-fidelity and dynamic vertical diving behaviours that varied between hotspots and seasons. These spatiotemporal data provide important ecological knowledge for sustainable management and the conservation of the recently recovered eastern ABFT stock. [ABSTRACT FROM AUTHOR]

A new dedicated coastal sea level dataset called the International Altimetry Service 2024 (IAS2024, https://doi.org/10.5281/zenodo.13208305 , Peng et al., 2024c) has been presented to monitor sea level changes along the world's coastlines. One of the reasons for generating this dataset is the quality of coastal altimeter data has been greatly improved with advanced coastal reprocessing strategies. In this study, the Seamless Combination of Multiple Retrackers (SCMR) strategy is adopted to obtain the reprocessed Jason data for January 2002 and April 2022. The evaluation results show that the data availability of the IAS2024 dataset over global coastal oceans is much higher than that of the European Space Agency Climate Change Initiative version 2.3 (ESA CCI v2.3) dataset. The closure of trend differences (0.16 ± 3.98 mm yr−1) between IAS2024 and Permanent Service for Mean Sea Level (PSMSL) tide gauge data is observed at the global scale, which further demonstrates the good performance of the IAS2024 dataset in monitoring the coastal sea level changes. The altimeter-based virtual stations have been built with the IAS2024 dataset over 0−10 km, 5−15 km and 10−20 km coastal strips, which will contribute to the analysis of coastal sea levels for the ocean community and the risk management for the policy makers. Our study also points out that no obvious variations exist in linear sea level trends from offshore to the coast in most coastal zones. In addition, the vertical land motion (VLM) estimates from the combination of coastal altimeter data with tide gauge records agree well with the University of La Rochelle 7a (ULR7a) Global Navigation Satellite System (GNSS) solution (0.09 ± 2.22 mm yr−1), suggesting that altimeter-derived VLM estimates can be an independent data source to validate the GNSS solutions. [ABSTRACT FROM AUTHOR]

Based on extensive ethnographic research on Mayotte (Indian Ocean), this article presents a case study on how environmentalism manifests in one of the world's richest biodiversity sites. It illustrates how Mayotte, the last and poorest French overseas department, is shaped by ‘hyper-environmentalism’ – where residents are forced to be ‘hyper-aware’, ‘hyper-educated’, and ‘hyper-committed’ to environmental issues. The paper discusses how Mayotte is constructed by the Wazungu ("white people") as a tropical ‘otherness’ and describes the process of ‘eco-infantilisation’, where the Maorais people are paternalistically portrayed as ‘children’ who need to be taught to ‘see’, ‘read’, and protect their environment. Finally, it shows how this effort to ‘change mindsets’ fails because it doesn't integrate new scientific knowledge with local expertises, which are often not recognised. The aim of this paper is to provide insights into the diverse manifestations of environmentalism in a post-colonial, tropical, insular, and ‘southern’ territory like Mayotte. [ABSTRACT FROM AUTHOR]

Copper, a malleable and ductile transition metal, possesses two stable isotopes. These copper isotopic composition data have recently found diverse applications in various fields and disciplines. In geology, copper isotopes serve as tracers that aid in investigating ore formation processes and the mechanisms of copper deposits Likewise, it has emerged as a valuable tracer in polluted environments. In plant biology, copper acts as an essential micronutrient crucial for photosynthesis, respiration, and growth. Copper isotopes contribute to understanding how plants uptake and dispense copper from the soil within their tissues. Similarly, in animals, copper serves as an essential trace element, playing a vital role in growth, white blood cell function, and enzyme activity. In humans, copper acts as an antioxidant, neutralising harmful free radicals within the body. It also helps in maintaining the nervous and immune system. Furthermore, copper isotopes find medical applications, particularly in cancer diagnostics, neurodegenerative diseases, and targeted radiotherapy. However, excessive copper can have detrimental effects in humans such as it can cause liver damage, nausea, and abdominal pain, whilst in plants it can affect the growth of plants, photosynthesis, and membrane permeability. This review emphasises the significance of copper and its isotopes in geology, the environment, and human health. [ABSTRACT FROM AUTHOR]

Global measurements of ocean pCO2 are critical to monitor and understand changes in the global carbon cycle. However, pCO2 observations remain sparse as they are mostly collected on opportunistic ship tracks. Several approaches, especially based on direct learning, have been used to upscale and extrapolate sparse point data to dense estimates using globally available input features. However, these estimates tend to exhibit spatially heterogeneous performance. As a result, we propose a physics-informed transfer learning workflow to generate dense pCO2 estimates that are grounded in real-world measurements and remain physically consistent. The models are initially trained on dense input predictors against pCO2 estimates from Earth system model simulation, and then fine-tuned to sparse SOCAT observational data. Compared to the benchmark direct learning approach, our transfer learning framework shows major improvements of up to 56-92%. Furthermore, we demonstrate that using models that explicitly account for spatiotemporal structures in the data yield better validation performances by 50-68%. Our strategy thus presents a new monthly global pCO2 estimate that spans for 35 years between 1982-2017. [ABSTRACT FROM AUTHOR]

The ocean has a key, though often unremarked, role in shaping everyday life, from impacting weather patterns and food supplies to facilitating, and contesting, systems of capitalism, including contemporary logistics, empires, mobility, and migration. Beginning with early debates on maritime anthropology, this review traces the shift from maritime anthropology to an anthropology of and from the ocean. It notes the ways that the ocean appears and disappears as metaphor or material space of encounter and engagement within the past, present, and possible futures of anthropology. It shows how absence and presence as well as metaphor and materiality are the modes through which oceans are imagined and inhabited. While there is no distinct oceanic turn in anthropology in contrast with a number of other disciplines, the anthropology of and from the ocean holds the possibility to reenergize anthropology's interdisciplinary encounters, including with history and geography, as well as modes of engaging scale and specificity. [ABSTRACT FROM AUTHOR]

The Sr chemostratigraphic characteristics of marine sediments of the Lower Permian in the Omolon massif of Northeast Asia have been obtained for the first time based on a study of well-preserved brachiopod shells. The 87Sr/86Sr ratio in brachiopods from the Lower Permian regional horizons (regional stages) is within the following ranges: 0.70786–0.70794, Orochian; 0.70744–0.70786, Ogonerian; 0.70745–0.70748, Koargychanian; and 0.70742–0.70735, Khalalian. The obtained Sr-isotope data demonstrate good agreement with the standard variation curve of the 87Sr/86Sr ratio in the Permian Ocean. New Sr-isotope data can be used to correlate the units of the Regional Stratigraphic Scale of Northeast Russia directly with the stages of the International Permian Stratigraphic Scale. Based on recent data, the Asselian age of the Orochian regional stage of the lower part of the Permian section in the Omolon massif has been proved, and the regional correlation of the Upper Sakmarian interval established previously from biostratigraphic data has been refined. [ABSTRACT FROM AUTHOR]

Ocean mesoscale eddy is a special mesoscale phenomenon in the ocean, which widely exists in all oceans and marginal seas around the world. Compared with ordinary ocean circulation, mesoscale eddy has high rotating speed, strong current velocity, and average vertical depths of several kilometres, which play an important role in ocean circulation and material transport. The traditional mesoscale eddy identification and recognition have great subjectivity and usually depends on the parameters predefined or adjusted by experts, which cannot guarantee the accuracy. With the development of artificial intelligence, deep learning method has also been widely used in the detection and recognition of ocean eddies. Based on the sea-level anomaly (SLA) data provided by Copernicus Marine Environment Detection Service, this study compares the results of the 'you only look once level feature' (YOLOF) model and Detectron2 model in deep learning on marine mesoscale eddy detection. The mesoscale eddies in the South China Sea from 2011 to 2013 are detected and identified. The accuracy of Detectron2 model is about 57%, while the accuracy of YOLOF model can reach 90%. Comparing the performance of the two models on the same data set, it can be found that YOLOF model improves the accuracy and speed of recognition to a certain extent. The deep learning network model provides an effective technical method for the study of mesoscale eddy detection by sea surface height. [ABSTRACT FROM AUTHOR]

Local ensemble transform Kalman filter (LETKF)‐based Ocean Research Analysis (LORA) version 1.0 datasets for western North Pacific (WNP) and Maritime Continent (MC) regions (LORA‐WNP and ‐MC, respectively) are released through the JAXA‐RIKEN Ocean Analysis website. The LORA datasets are created using an eddy‐resolving LETKF‐based ocean data assimilation system with satellite sea‐surface temperature, salinity, and height data and with in‐situ temperature and salinity data assimilated daily. The LORA datasets include 128‐member ensemble analyses at the sea surface (2D), each term of mixed‐layer temperature and salinity budget equations, and the related variables (2D) such as mixed‐layer depth and heat and freshwater fluxes as well as system grid information and analysis ensemble mean and spread (3D), from August 2015 to January 2024 (as of June 2024). The LORA datasets are useful for geoscience research and practical applications, especially for particle tracking, boundary conditions of atmospheric models, and research on spatiotemporal variations in sea‐surface temperature and salinity. [ABSTRACT FROM AUTHOR]

For more than three decades, satellite altimetry has provided valuable measurement data for the monitoring and analysis of ocean and inland water surfaces. Since 1992, there have always been at least two simultaneous missions providing continuous measurement data, starting with TOPEX/Poseidon and ERS‐1 in the early 1990s and continuing with about 10 satellites active today, including ICESat‐2, Sentinel‐6A and SWOT. Most mission data are freely available, but in different formats, processing levels and with respect to different references (e.g. ellipsoid or time), making common multi‐mission applications difficult. In addition, the derivation of ready‐to‐use and high‐quality scientific products requires expertise that not every user is willing to acquire. Over the years, DGFI‐TUM has developed and maintained an Open Altimeter Database (OpenADB) that allows consistent data management and combination. It consists of the internal Multi‐Version Altimetry (MVA) data repository and the OpenADB web portal. OpenADB provides user‐friendly access to derived along‐track products, such as sea surface heights and ocean tides. It also provides general information about the satellite altimetry missions, their observing configurations and about the data provided in the database. All products are freely available on the OpenADB web portal (https://openadb.dgfi.tum.de) after registration. [ABSTRACT FROM AUTHOR]

The Qinling‐Dabie‐Sulu orogen is the eastern part of the Central China Orogenic Belt. Looking back on previous studies of the sedimentary record we systematically compiled the dataset of detrital zircon U–Pb ages and Hf isotopes for this orogenic belt. The dataset incorporates a comprehensive compilation of 32,449 detrital zircon U–Pb ages and 979 Hf isotopes. The findings demonstrate that distinct tectonic units within the orogenic belt exhibit unique tectonic evolution histories during various geological epochs. This dataset can be used to constrain the tectonic framework and orogenic evolution including ocean subduction, continental collision and orogen exhumation. It can be integrated with other geological datasets to improve our understanding of the Central Orogenic Belt in China, and possibly plate tectonics globally. [ABSTRACT FROM AUTHOR]

The Data Interpolation Empirical Orthogonal Function (DINEOF) algorithm is used to reconstruct datasets of geophysical and biological variables such as sea surface temperature (SST) and chlorophyll a (Chl a). In this study, we analyze the impact of both the quantity and distribution of missing data on the performance of DINEOF demonstrating how DINEOF plus a connectivity mask can be used for future data reconstruction tasks. We propose an enhanced version of DINEOF (DINEOF+) by adding two steps: 1) Using a 75% threshold of missing data for reconstructing incomplete datasets and 2) masking interpolated points that lack sufficient space–time observations in the original dataset. We successfully apply DINEOF+ to the Ocean Color Climate Change Initiative (OC-CCI) global daily Chl a dataset and validate the results using in situ datasets. We find that the recovery rate varies across ocean basins and years. In oligotrophic waters, the daily data coverage increased by 40%–50% during the period from 2003 to 2020. Using DINEOF+ allows us to obtain a significantly higher temporal resolution of global Chl a data, which will improve understanding of marine phytoplankton dynamics in response to changing environments. Significance Statement: We perform an error analysis on the application of DINEOF for reconstructing a global Chl a dataset. The results of this analysis illustrate the impact of missing data—both in terms of quantity and distribution—on the performance of DINEOF. We propose using DINEOF+, an enhanced version of DINEOF that adds an editing step to mask out interpolated points based on the number of surrounding observations in the original input. The performance of DINEOF+ was validated using both simulated and in situ datasets. The results indicate that employing this masking technique effectively reduces biased estimates of missing data. DINEOF+ can be applied to other biogeochemical variables. However, caution is advised when dealing with observations characterized by high variance. [ABSTRACT FROM AUTHOR]

Attacks by the Houthis, an Iran-backed armed group from northwest Yemen and now its de facto governing authority, pose a significant threat to commercial shipping in the Red Sea and the Gulf of Aden, and therefore to the global economy. Washington faces a range of unpalatable options to deal with this threat. The current approach of limited American and British airstrikes is flawed, but the alternatives – no airstrikes or more airstrikes – are arguably worse. Under a more ambitious strategy, the United States would through diplomacy help rebuild the internationally recognised government of Yemen, which nominally brings together anti-Houthi factions but is in fact fragmented and weak. Only this option has a realistic prospect of modifying the balance of power inside Yemen and containing the Houthis' regional threat. Otherwise, the Houthis are likely to consolidate power, which would be a tragedy for the Yemeni people given the brutality of Houthi rule, and present a perennial danger to regional security given their ambitions. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effectiveness of an ocean culture course using the TRIP learning model (Triggered situational interest-Reading-Inquiry-Presentation) in enhancing students' marine life concepts and learning interests. The participants consisted of 67 first-graders (six years old). A quasi-experimental design was employed, and the mixed methods analysis was used in this study. The results showed that the experimental group students' concepts of marine life were improved with a large effect size (d = 1.4), and they outperformed their counterparts with a large effect size (f =.40). The students' learning interest in marine ecological conservation concepts was improved with a medium effect size (d =.53), and they outperformed their counterparts with a large effect size (f =.54). The results revealed that using the TRIP learning model for ocean education improved the teaching of the teachers who taught the experiment group. Moreover, the model enhanced the effectiveness of students' learning interest in understanding marine life and marine ecological conservation concepts. Finally, some suggestions for further teaching and research were provided. [ABSTRACT FROM AUTHOR]

While decadal changes in Madden–Julian oscillation (MJO) have received considerable attention, the corresponding changes in Boreal Summer Intraseasonal Oscillation (BSISO) have yet to be well understood. In this study, we show the enhanced northward propagation of BSISO in the Western North Pacific (WNP) during the 2000s compared to the 1980s–1990s. Observational analyses and model experiments suggest this enhancement is partially attributed to the tropical Indian Ocean (TIO) warming. The TIO warming tends to increase the air-sea interaction, enhancing moisture anomalies in the free atmosphere. Consequently, this increase in moisture anomalies strengthens BSISO-scale convection through increased convective anomalies at the north of the BSISO center, thereby enhancing the northward propagation of BSISO. Additionally, vorticity changes resulting from mean-state zonal vertical shear also contribute to the BSISO decadal change. Our findings underscore the importance of considering the interaction between BSISO and changes in the ocean mean state in future assessments. [ABSTRACT FROM AUTHOR]

Observations of the seafloor Rayleigh ellipticity contribute to seismic imaging in the ocean. To extract such observables from the arbitrarily oriented ocean–bottom seismometer (OBS) data, we develop an orthogonal-regression-based approach to measure the waveform amplitude ratios of the unoriented horizontal and vertical components. The amplitude ratios are then used to calculate the Rayleigh ellipticity (and the sensor orientation angle). The robustness of our method is verified by applications to both the unoriented OBS data and the well oriented on-land seismic data. As we propose to calculate the Rayleigh ellipticity directly from the unoriented three-component data, the measurement process avoids the complexity arising from the surface wave non-great-circle effects and uncertainties of the OBS sensor orientation angles. Overall the Rayleigh ellipticity measurements from our method are systematically higher than those by conventional analysis and show less uncertainties. Our analyses suggest that the Rayleigh ellipticity curve (14–60 s), which could be retrieved from the raw broad-band OBS data, is effective to constrain the oceanic lithosphere structure, and the accurate measurement of Rayleigh ellipticity curve is important. The potential of seafloor Rayleigh ellipticity for seismic imaging in the ocean is evidenced by a case study of the Japan Basin, the Sea of Japan. Considering the insufficient station coverage in the ocean, the single-station measurement of seafloor Rayleigh ellipticity is of significance for OBS community. [ABSTRACT FROM AUTHOR]

The ocean is the largest active carbon reservoir on Earth. Organic carbon (OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study, sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea, Yellow Sea, and East China Sea (BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.12%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr−1. Among them, the burial flux of biospheric OC is 6.92 Mt C yr−1, equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO2, indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment, while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas. [ABSTRACT FROM AUTHOR]

A reduced-order model (ROM) of the global oceans is developed by projecting the hydrostatic Boussinesq equations of motion onto a proper orthogonal decomposition (POD) basis. Three-dimensional POD modes are calculated from the ocean fields of an ensemble climate reanalysis dataset. The coefficients in the POD ROM are calculated using a regression approach. The performance of various POD ROM configurations are assessed. Each configuration is derived from an alternate sea-water equation of state, linking the density and temperature fields. POD ROM variants incorporating an equation of state in which density is a quadratic function of temperature, are able to reproduce the statistics of the large-scale structures at a fraction of the computational cost required to numerically simulate this flow. Due to the speed and efficiency of calculation, such reduced-order models of the global geophysical system will enable researchers and policy makers to assess the physical risk for a broader range of potential future climate scenarios. [ABSTRACT FROM AUTHOR]

The article addresses a two-fold question: first, why does the French state invest so much time and resources in its Indian Ocean islands, Mayotte and Réunion? And why do these ultra-marine regions remain wedded to the French Republic? The high degree of insular buy-in both regions involves a two-level game, connecting state and island actors. Such turning to mainland France represents a form of African agency, however dependent on the mainland these islands appear to be. The causal mechanisms of the integration of the French Indian Ocean territories combine historical legacy (choosing France), institutional evolution (departmentalisation), common economic and military security challenges, the cost calculus of mainland France's readiness to govern ultramarine territories and a widely shared set of beliefs in the value of remaining French. The islands are acting like rational actors, whose insular and isolated status pushes in the direction of seeking protection in an unstable environment. [ABSTRACT FROM AUTHOR]

The article presents a comparative analysis of the Paleozoic and Cenozoic reef formation, mainly in terms of the position of reefs in the basins of continental and oceanic blocks. It is shown that the main formation of reefs took place in the Cenozoic directly in the oceans, including boundaries between oceans and continents, and, to an extremely limited scales, in the basins of the continental segment. In the Paleozoic, reefs were formed not only in oceans, but also in spacious basins of continental block. This is one of the manifestations of the general evolution of carbonate accumulation, when the Paleozoic carbonate sediments were formed in such shallow-water bodies that covered very significant surfaces of continents. [ABSTRACT FROM AUTHOR]

A surface layer (upper 20 m depth) heat budget analysis, derived from a hindcast regional-scale ocean modeling experiment, was employed to examine the underlying mechanisms behind the emergence of sea surface temperature anomalies (SSTA) in the Indonesian seas during El Niño events over the 1995–2019 course. Prior to the emergence of warm SSTA, which typically appeared following the mature phase of El Niño and lasted for almost a year, apparent anomalous heat accumulation occurred for at least 2–4 months and peaked in conjunction with the climatic event. Further examination revealed possible east–west distinct dynamics in the heat budget variations within the region during El Niño years. The anomalous heat accumulation in the western part of Indonesian seas (Java Sea) was predominantly caused by modulation in the surface net heat flux. Whereas in the eastern part (Banda Sea), the ocean circulation also exerted important influence in addition to the surface net heat flux. The ocean circulation in the eastern Indonesian seas notably contributed to moderate the effect of surface net heat flux during El Niño growth. Moreover, the same ocean circulation was responsible for prolonging the anomalous heat accumulation in the eastern Indonesian seas from mature to decay phase of the El Niño, ultimately resulted in warmer SSTA than that in the western part. The study conducted here provides additional insights on how the Indonesian seas responded to the El Niño and further reaffirms the idea that the climatic event results in anomalous warming across the Indonesian seas. [ABSTRACT FROM AUTHOR]

Recent studies show that stoichiometric elemental ratios of marine ecosystems are not static at Redfield proportions but vary systematically between biomes. However, the wider Atlantic Ocean is undersampled for particulate organic matter (POM) elemental composition, especially when it comes to phosphorus (i.e., POP). Thus, it is uncertain how environmental variation in this region translates into shifts in the C:N:P ratio. To address this, we analyzed hydrography, genomics, and POM concentrations from 877 stations on the meridional transects AMT28 and C13.5, spanning the Atlantic Ocean. We observed nutrient-replete, high-latitude ecosystem C:N:P to be significantly lower than that in the oligotrophic gyres. Latitudinal and zonal differences in elemental stoichiometry were linked to overall nutrient supply as well as N vs. P stress. C:P and N:P were generally higher in the P-stressed northern region compared to Southern Hemisphere regions. We also detected a zonal difference linked to a westward deepening nutricline and a shift from N to P stress. We also evaluated possible seasonal changes in C:N:P across the basin and predicted these to be limited. Overall, this study confirms latitudinal shifts in surface ocean POM ratios but reveals previously unrecognized hemisphere and zonal gradients. This work demonstrates the importance of understanding how regional shifts in hydrography and type of nutrient stress shape the coupling between Atlantic Ocean nutrient and carbon cycles. [ABSTRACT FROM AUTHOR]