Sea Surface Temperature Products Research Articles

Decadal intensified and slantwise Subpolar Front in the Japan/East Sea

The Subpolar Front in the Japan/East Sea (JES) could far-reaching influence the atmospheric processes over the downstream regions. However its variability on decadal timescale remains less understood. In this study, the decadal trends in the intensity and position of the SPF in the JES during the time period 1985−2020 are analyzed by using four categories of satellite observed high-resolution sea surface temperature products. The results show that there is a significant intensification trend of the SPF at a rate of 0.37°C/100km/decade. The SPF is further divided into three regions based on the meridional sea surface temperature gradient (MSSTG): the eastern (135−138°E), central (130−135°E) and western (128−130°E) regions, respectively. These three regions showed different meridional movements with the eastern SPF moving poleward by 0.08°/decade, the central SPF moving equatorward by −0.11°/decade and the western SPF showing no significant displacements. The reverse meridional movements between the central and eastern SPF increased its skewness. The frontogenesis rate equation is employed to identify the mechanisms of these decadal trends. Results show that the geostrophic advection term, especially its zonal component, had a crucial role in the decadal trends of the intensity and position of the central and eastern SPF. The decadal trend of the central SPF was mainly attributed to the zonal geostrophic advection of the MSSTG associated with the enhancement of the Subpolar Front Current (SFC) in the upstream region, whereas the decadal trend in the eastern SPF was mainly driven by the zonal geostrophic shear advection controlled by the shear of the SFC in the downstream region. Before 2002, the eastern SPF moved poleward at a rate of 0.27°/decade, whereas there was no obvious trend after 2002. Further decomposition showed that this shift was caused by meridional Ekman advection of the MSSTG.

Southern westerly winds and paleoceanography of the San Jorge Gulf (SW-Atlantic ocean, Argentina) during the last 14,000 years

We use pollen and dinocyst assemblages from three sedimentary sequences of the San Jorge Gulf (SJG) to document the vegetation history of the extra-Andean/eastern Patagonia (Argentina), and the latitudinal variations of the Southern Westerly Wind Belt (SWWB) in relation with ocean changes during the Late Pleistocene and Holocene. Our results suggest that prior to 14 cal ka BP, the vegetation of the SJG was dominated by halophytic taxa probably related to arid conditions in coastal environments. After 14 cal ka BP, pollen data suggest the development of shrub and herb vegetation in the Patagonian steppe then characterized by semi-arid conditions. The 14 cal ka BP transition is marked by increasing Nothofagus pollen abundances, suggesting strong westerlies at the onset of the Antarctic Cold Reversal (ACR). This transition is also marked by the occurrence of marine palynomorphs (dinocysts, organic linings of foraminifers), which relate to sea-level rise. The dinocyst assemblages allowed us to quantitatively estimates changes in summer sea-surface temperature (SST) and annual net primary productivity. Between 14 and 10.8 cal ka BP, which encompasses the glacial termination and the early Holocene, dinocyst assemblages are dominated by Operculodinium centrocarpum (∼82%) and Spiniferites mirabilis (∼8%) that suggest warmer conditions than at present. The transition from early to middle Holocene was marked by high SWWB intensity as suggested by pollen assemblages, and an increase of heterotrophic taxa such as Brigantedinium spp., Echinidinium sp., Dubridinium sp., and the cysts of Polykrikos kofoidii, suggesting increased primary productivity and gradual cooling of surface water. After 4 cal ka BP, pollen data suggest a decrease in the SWWB intensity that correlates with glacier advances in Patagonia and a further decrease in summer SST in the SJG.

Assessing the ability of satellite sea surface temperature analyses to resolve spatial variability – The northwest tropical Atlantic ATOMIC region

Direct measurements of the sea surface temperature (SST) from multiple platforms deployed during the Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) field campaign are used to evaluate the ability of satellite SST products to accurately represent spatial gradients within the region. The results further provide insight into the suitability of different satellite SST products for application to ATOMIC and other northwest tropical Atlantic scientific analyses. In situ SST measurements from the Research Vessel Ronald H. Brown, Saildrones, and Surface Velocity Program – Salinity (SVPS) drifters were collocated with five daily Level 4 satellite SST analyses and two Level 3 single-sensor satellite SST products during the period from January 1 to February 24, 2020. The absolute accuracy of the satellite products was generally good with random errors on the order of 0.2 K or less, though most exhibited a small cool bias of ∼0.1 K. The biases were not representative of a consistent offset, but rather larger cool biases of a subset of observations influenced the overall statistics. Sub-grid SST variability in the ATOMIC region was small (< 0.03 K) in relationship both to other regions and to uncertainties in the satellite products. Despite their absolute accuracy, the L4 analyses accurately reproduced the spatial SST variability within the ATOMIC domain only on scales of 0.5–1° or more. At the scale of their respective grid resolutions, correlations between satellite-derived and Saildrone-inferred grid-scale SST gradients were low, as the satellite–Saildrone SST differences dominated over small cell-to-cell variability in the region. One reason was the coarser feature resolution of the analyses compared to their grid resolution. Correlations increased with the distance over which the SST values were averaged. Simulations demonstrated that a satellite product precision near 0.05 K was needed to successfully reproduce the observed SST spatial variability at the grid cell level. Comparison with Saildrone observations from the Arctic showed sub-grid SST variability six-times larger and a relaxed satellite accuracy requirement of near 0.5 K in that region, but the satellite product accuracy was also degraded, again hindering the accurate sampling of SST gradients at the scale of the L4 analyses.

Marine Heatwaves in the South China Sea: Tempo-Spatial Pattern and Its Association with Large-Scale Circulation

A marine heatwave (MHW) can significantly harm marine ecosystems and fisheries. Based on a remotely sensed sea surface temperature (SST) product, this study investigated MHWs behaviors in the South China Sea (SCS) throughout the warm season (May to September) from 1982 to 2020. The distributions of the three MHW indices used in this study showed significant latitudinal variations: more frequent, longer, and more intense MHWs appear in the northern SCS, and less frequent, shorter, and weaker MHWs appear in the southern SCS. Using the empirical orthogonal function (EOF) method, we found that the first leading modes of the three MHW indices account for more than half of the total variance. The first leading modes reveal uniform anomalies throughout the SCS, with the maximum in the deep central portion and its surroundings. Their corresponding time series showed significant interdecadal variations, with a turning point around 2009. Since 2010, the SCS has seen an increase in the frequency, length, and severity of MHWs. The incidence of MHWs has been linked to the presence of stable near-surface anticyclonic anomalies, which reduced cloud cover and increased solar radiation. This abnormal pattern was usually accompanied by the intensification and westward shift of the western North Pacific subtropical high (WNPSH). The findings imply that MHWs in the SCS may be predictable on interannual and decadal scales.

Effects of oceanography on North Pacific armorhead recruitment in the Emperor Seamounts

AbstractThe North Pacific armorhead (NPA), Pentaceros wheeleri, is thought to exhibit an extended post‐spawning epipelagic phase in which larvae disperse to the northeast Pacific Ocean. Current understanding of juvenile distribution, development, and mechanisms that drive recruitment variation, however, remains largely incomplete. The objective of this study was to compare a time series of NPA recruitment to established climate indices and to environmental covariates to explore drivers of the NPA life cycle. Additionally, this work investigates potential larval NPA transport pathways and their positional relationships to the proposed northeastern nursery grounds. Using Lagrangian particle tracking, trajectories of passive larvae were simulated at depths of 0 and 15 m for 18 years (2001–2018) from the Southern Emperor‐Northern Hawaiian Ridge (SE‐NHR) natal habitat. Dispersal distances and particle end positions were examined for their potential relationships with recruitment. Sea surface temperature and net primary productivity were evaluated as predictor variables using generalized additive modeling. Neither regression of particle end‐point characteristics nor environmental covariates resulted in significant correlations with recruitment here, perhaps owing to data limitations surrounding the nursery zone. Particles were found to be advected largely within the North Pacific transition zone in the central north Pacific. Significant seasonal correlations were found between recruitment and the Arctic Oscillation, Pacific Decadal Oscillation and North Pacific Gyre Oscillation, suggesting that NPA recruitment mechanisms respond to interannual ocean‐atmospheric climate oscillations. Better knowledge of the connections between recruitment and the environment would be valuable for stock management, and improvements for advection predictions are discussed.

Alteration of alpha and beta diversity in nekton community by extreme marine heatwave events: An example from the East China Sea

In the year of 2016 to 2017, record-breaking marine heatwave (MHW) events occurred along the Chinese coast, exerting severe impacts on coastal fishes and fisheries. However, the response of the nekton community to MHW events still remains poorly understanding. Thus, to investigate the influences of the MHW events on species composition dynamics, this study conducted a survey on nekton communities in the northern East China Sea in the summers during 2014 to 2017. The recently-developed “heatwaveR” package was adopted to describe the variation characteristics of heatwaves within the study area, based on high-resolution remote-sensing sea surface temperature products. We also compared variations in the community structures of different biological groups before (2014–2015) and during the occurrence of the MHW events (2016–2017). During the MHW events, temperature increased by approximately 2.3°C in both 2016 and 2017. Compared with those before the MHW events, the biomass and dominance of several important crustaceans decreased, and the biomass of warm water affinity species increased significantly, while their richness and diversity decreased; the biomass of warm temperature affinity species declined significantly, while their diversity increased slightly. These results show the difference in the response rates of species with different thermal preferences and different species compositions to the extreme climate change. Beta diversity analysis revealed that the inter-group variation before and during the MHW event exceeded the intra-group variation, proving that MHWs changed the community structure to a certain extent. PERMANOVA test showed that the species compositions of planktivorous fish (FG1) and small-omnivorous fish (FG2) in the feeding-functional groups were significantly different before and during the MHW event, which may be attributed to the impact of MHWs on oligotrophic fishes through thermal preference and the trophic cascade effect. There was no significant change in the species compositions of other functional groups, indicating that medium-trophic and eutrophic fishes possessed certain adaptability to MHWs. Regarding fisheries management under extreme warming events, it would be advisable to diagnose temperature anomalies in the early stage, monitor changes in species abundance in the early life cycle, and then rapidly develop suitable fishing strategies.

The influence of increasing sea surface temperature on particulate organic carbon in Indonesian waters based on MODIS Aqua satellite

Both Sea Surface Temperature (SST) and Particulate Organic Carbon (POC) have important roles in the marine ecosystem and carbon cycle. Therefore, we analyze the influence of SST on POC in Indonesian water. We used SST and POC products from the moderate-resolution imaging spectroradiometer (MODIS) Aqua satellite from 2003 to 2021 (nineteen years). Regression and a temporal anomaly correlation approach were applied to assess the effect of SST on POC in Indonesian waters. Our results show that the southeast Indonesian waters, south of Java Island and around the Riau Islands, mostly have a high SST variation. On the other hand, the high variation of POC mostly appeared in Indonesian coastal. During the last nineteen years, the increasing SST anomalies (SSTA) in Indonesian waters have been followed by decreasing POC anomalies (POCA). These results indicate that rising SST reduces the ocean’s ability to absorb carbon in Indonesian waters. A strong negative relation between SSTA on POCA was found from April to August and October to January in a seasonal timescale. In the interannual timescale, our result reveals that the strong negative relationship between SSTA and POCA is likely linked to the El Niño Southern Oscillation, the Indian Ocean Dipole, and global warming.

Middle to Late Holocene Sea Surface Temperature and Productivity Changes in the Northeast Pacific

AbstractVariations of the sea surface temperature (SST) and primary productivity in the northeast Pacific have far‐reaching implications. In addition to influencing the regional and global temperature and hydroclimate, these conditions also control marine ecosystems and their services, which subsequently impact regional economies. Yet, our understanding of the variability and controls of northeast Pacific SST and productivity on timescales exceeding observational records remains limited. Here, we use marine sediment records from seven locations, spanning 25.2°N–59.6°N, in the northeast Pacific to characterize the millennial‐scale variability of SST and productivity from 9,000 to 1,000 years BP. We explore the dynamics of their spatiotemporal evolution and compare these data with transient climate model outputs to identify potential drivers. Through a heat budget analysis and optimal fingerprinting analysis, we characterize the spatial pattern of forcings. We find that SST varied spatially in the northeast Pacific, with higher latitudes exhibiting greater magnitude changes than lower latitudes, which differs from previous work suggesting regional synchronicity and coherence during the Holocene. Our analysis did not find evidence for coherent variability of primary producer community nor carbon export, highlighting the difficulty of identifying the complex interactions between environmental conditions, producers, and carbon export. Model‐proxy disagreement demonstrates the need for higher resolution model frameworks, but shows nonetheless that observed variability in the proxy records can be explained by a combination of greenhouse gas and orbital forcing. We suggest that the complex SST variations and marine ecosystem responses to forced changes are important factors that can drive disagreements in model projections.

Long-term variability of satellite derived total alkalinity in the southwest Bay of Bengal

The seasonal and inter-annual variability of Total Alkalinity (TA) concentration was studied in the Bay of Bengal from 2003 to 2019 by using MODIS-Aqua derived sea surface temperature (SST) and sea surface salinity (SSS) products. The satellite derived TA showed a positive relationship with in-situ TA with (R2 = 0.67, RMSE = ±27.53 μMol/kg, SEE = ±32.16 and uncertainty error = 2287μMol/kg). The seasonal SST, SSS and TA portray the clear seasonal pattern between the seasons without any rapid change increase or decrease in trend observed over the years. In contrast to other seasons, the spring inter-monsoon was observed to have a warm surface water temperature with high salinity and TA. Strong wind and excessive cloud cover during the summer monsoon result in the reduction of ocean surface heat, which favours sea surface cooling and shallow mixed layer depth, resulting in low SST, SSS, and TA compared to the spring inter-monsoon. During fall inter-monsoon, the reversal of East India coastal current directs warm water from north to south and the weak wind that prevails in this region enhances stratification. During winter, low-saline water compensates the static stability loss by thermal inversion from the sea surface resulting in surface cooling with coldest SST, low SSS and TA during this period.

Citizen scientists’ dive computers resolve seasonal and interannual temperature variations in the Red Sea

Dive computers have the potential to provide depth resolved temperature data that is often lacking especially in close to shore, but spatiotemporal assessment of the robustness of this citizen science approach has not been done. In this study, we provide this assessment for the Red Sea, one of the most dived areas in the world. A comparison was conducted between 17 years of minimum water temperatures collected from SCUBA dive computers in the northern Red Sea (23–30° N, 32–39.4° E), satellite-derived sea surface temperatures from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) optimal interpolation product, and depth-banded monthly mean in-situ temperature from the TEMPERSEA dataset, which incorporates data originating from several in-situ recording platforms (including Argo floats, ships and gliders). We show that dive computer temperature data clearly resolve seasonal patterns, which are in good agreement in both phase and amplitude with OSTIA and TEMPERSEA. On average, dive computer temperatures had an overall negative bias of (–0.5 ± 1.1) °C compared with OSTIA and (–0.2 ± 1.4) °C compared with TEMPERSEA. As may be expected, increased depth-related biases were found to be associated with stratified periods and shallower mixed layer depths, i.e., stronger vertical temperature gradients. A south-north temperature gradient consistent with values reported in the literature was also identifiable. Bias remains consistent even when subsampling just 1% of the total 9310 dive computer datapoints. We conclude that dive computers offer potential as an alternative source of depth-resolved temperatures to complement existing in situ and satellite SST data sources.

Very high Middle Miocene surface productivity on the U.S. mid-Atlantic shelf amid glacioeustatic sea level variability

The Miocene Climatic Optimum (MCO) provides important insights into how the climate system operates under elevated temperatures and atmospheric CO2 levels. Few western North Atlantic paleotemperature or paleoecological records exist from the MCO, despite their importance for understanding both regional and global climate dynamics. Here we present quantitative MCO paleoecological data from the western North Atlantic, specifically from the Baltimore Gas & Electric (BG&E) marine sediment core from southern Maryland, USA. We examine alkenones and planktic foraminifera and document the first sea surface temperature (SST) and productivity estimates for the MCO and the Middle Miocene Climate Transition (MMCT) from the continental shelf. Increased levels of planktic foraminifer species diversity and surface productivity accompany high sea level intervals of the MCO, indicating coastal upwelling. Cooling episodes correlate to unconformities in the BG&E core that reflect sea level lowstands; these and sedimentary cycles tie the record to eccentricity-paced Antarctic ice sheet growth and decay. This dynamic record not only captures the variability in SST, sea level and coastal productivity during the warm MCO and the transition to cooler global temperatures during the MMCT, but it also demonstrates the variability in local conditions within and between intervals of high sea level.

Generation and Assessment of ARGO Sea Surface Temperature Climatology for the Indian Ocean Region

ARGO program was conceived with an aim to generate near real-time ocean observations as the primary in-situ sources for use in operational oceanography studies. Two decades-long ARGO near-surface temperature data set was used for generating monthly gridded ARGO sea surface temperature (ASST) product on a climatological scale. Data interpolating variational analysis (DIVA) method was employed for generating the product with a spatial resolution of 0.25° x 0.25° for the Tropical Indian Ocean. This monthly ASST product was evaluated using five different climatological SST products derived from in-situ and satellite measurements. Various statistics such as BIAS, RMSE, coefficient of correlation, and skill scores were generated to evaluate the reliability of the ASST product. Further, the ASST product was validated with climatological in-situ SST obtained from RAMA and OMNI moorings deployed in the Indian Ocean. Statistical comparisons showed low BIAS and RMSE, and high correlation and skill scores with most of the buoys locations and the gridded SST products. Results concluded that the near-surface temperature data from ARGO can be used along with other SST data sets in the generation of high-resolution blended SST products.

A new operational Mediterranean diurnal optimally interpolated sea surface temperature product within the Copernicus Marine Service

Abstract. Within the Copernicus Marine Service, a new operational MEDiterranean diurnal optimally interpolated sea surface temperature (MED DOISST) product has been developed. This product provides hourly mean maps (level 4) of subskin SST at 1/16∘ horizontal resolution over the Mediterranean Sea from January 2019 to the present. Subskin is the temperature at ∼1 mm depth of the ocean surface and then potentially subjected to a large diurnal cycle. The product is built by combining hourly SST data from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board the Meteosat Second Generation and model analyses from the Mediterranean Forecasting System (MedFS) through optimal interpolation. SEVIRI and MedFS (first layer) SST data are respectively used as the observation source and first guess. The choice of using a model output as first guess represents an innovative alternative to the commonly adopted climatologies or previous day analyses, providing physically consistent estimates of hourly SSTs. The accuracy of the MED DOISST product is assessed here by comparison against surface drifting buoy measurements covering the years 2019 and 2020. The diurnal cycle reconstructed from DOISST is in good agreement with the one observed by independent drifter data, with a mean bias of 0.041±0.001 K and root mean square difference (RMSD) of 0.412±0.001 K. The new SST product is more accurate than the input MedFS SST during the central warming hours, when the model, on average, underestimates drifter SST by 1/10 of a degree. The capability of DOISST to reconstruct diurnal warming events, which may reach intense amplitudes larger than 5 K in the Mediterranean Sea, is also analyzed. Specifically, a comparison with the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) diurnal skin SST product, SEVIRI, MedFS, and drifter data shows that the DOISST product is able to reproduce more accurately diurnal warming events larger than 1 K. This product can contribute to improving the prediction capability of numerical models that assimilate or correct the heat fluxes starting from level 4 SST data and the monitoring of surface heat budget estimates and temperature extremes which can have significant impacts on the marine ecosystem. The full MED DOISST product (released on 4 May 2021) is available upon free registration at https://doi.org/10.48670/moi-00170 (CNR, 2021). The reduced subset used here for validation and review purposes is openly available at https://doi.org/10.5281/zenodo.5807729 (Pisano, 2021).

Argo Reveals the Scales and Provenance of Equatorial Island Upwelling Systems

AbstractEquatorial islands have distinct oceanographic signatures, including cool sea surface temperature and high productivity immediately to their west. It has long been hypothesized that topographic upwelling is responsible for such characteristics—upward deflection by the islands of the eastward‐flowing equatorial undercurrent (EUC). Using 22 years of in situ measurements by Argo, we provide the first direct observations of this process occurring with consistency at two prominent archipelagos in the equatorial Pacific. Argo measurements resolve a clear subsurface thermal fingerprint of vertical divergence at the depth of the EUC, confined to within 100 km of both the Gilbert (∼175°E) and Galápagos Islands (∼90°W). This signal at the Galápagos is well‐reproduced by a high‐resolution ocean reanalysis, enabling the estimation of vertical velocities balancing the zonal convergence of the EUC upon the islands. This sharpened view of the physics underpinning such important tropical ecosystems has implications for strategies to model and predict them.

Warm bias of cold sea surface temperatures in the East Sea (Japan Sea)

The East/Japan Sea (ES) is regarded as a natural laboratory for predicting future changes in the global Meridional Overturning Circulation (MOC) under warming climates, as the ES MOC (EMOC) changes rapidly in comparison with the global MOC. Specifically, intermediate and deep-water masses of the ES are formed in its northern reaches via wind-driven subduction of surface water, and convection from the surface to deep layers during the winter. Accordingly, it is important to investigate the variation of winter sea surface temperatures (SSTs) for characterizing and predicting the EMOC; however, global SST products must be corrected and optimized for the ES, as they fail to incorporate the local marginal sea conditions. Here, a warm bias in cold SST was identified for three SST products, such as optimally interpolated sea surface temperatures (OISSTs), microwave SSTs, and operational SST and sea ice analysis products, suggesting the potential usefulness of a correction method incorporating Argo float data. When comparing OISSTs with 5 m temperature estimates from Argo float data during 2000–2020, under the assumption that the mixed layer depth is deeper than 8 m, a nearly normalized histogram of biases was produced, and the robust warm bias (mean = 0.9°C) was detected in the range of relatively cold SSTs (-2°C to 10°C), yet no significant bias in warm SSTs (&amp;gt; 10°C) was found. To minimize the warm bias in cold SSTs, OISSTs were corrected with an inverse 4th-order polynomial fitting method. Subsequently, the mean bias between the corrected SSTs and top depth temperatures of Argo float data was significantly reduced to less than 0.1°C. Moreover, the warm bias of cold SSTs resulted in severe underestimations of the outcropping area colder than 1°C over the northern region, as well as the occurrence period of 1°C to 5°C SSTs in the north-western ES. These results highlight the importance of local bias correction for SST products, and it is expected that the newly suggested correction method will improve model predictions of EMOC change by enhancing SST data quality in the northern ES.

Multi-Sensor Sea Surface Temperature Products from the Australian Bureau of Meteorology

Sea surface temperature (SST) products that can resolve fine scale features, such as sub-mesoscale eddies, ocean fronts and coastal upwelling, are increasingly in demand. In response to user requirements for gap-free, highest spatial resolution, best quality and highest accuracy SST data, the Australian Bureau of Meteorology (BoM) produces operational, real-time Multi-sensor SST level 3 products by compositing SST from Advanced Very-High-Resolution Radiometer (AVHRR) sensors on Meteorological Operational satellite (MetOp)-B and National Oceanic and Atmospheric Administration (NOAA) 18, along with SST from Visible Infrared Imaging Radiometer Suite (VIIRS) sensors on the Suomi National Polar-orbiting Partnership (Suomi NPP) and NOAA 20 polar-orbiting satellites for the Australian Integrated Marine Observing System (IMOS) project. Here we discuss our method to combine data from different sensors and present validation of the satellite-derived SST against in situ SST data. The Multi-sensor Level 3 Super Collated (L3S) SSTs exhibit significantly greater spatial coverage and improved accuracy compared with the pre-existing IMOS AVHRR-only L3S SSTs. When compared to the Geo Polar Blended level 4 analysis SST data over the Great Barrier Reef, Multi-sensor L3S SST differs by less than 1 °C while exhibiting a wider range of SSTs over the region. It shows more variability and restores small-scale features better than the Geo Polar Blended level 4 analysis SST data. The operational Multi-sensor L3S SST products are used as input for applications such as IMOS OceanCurrent and the BoM ReefTemp Next-Generation Coral Bleaching Nowcasting service and provide useful insight into the study of marine heatwaves and ocean upwelling in near-coastal regions.

FOCI-MOPS v1 – integration of marine biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model

Abstract. The consideration of marine biogeochemistry is essential for simulating the carbon cycle in an Earth system model. Here we present the implementation and evaluation of a marine biogeochemical model, the Model of Oceanic Pelagic Stoichiometry (MOPS) in the Flexible Ocean and Climate Infrastructure (FOCI) climate model. FOCI-MOPS enables the simulation of marine biological processes, i.e. the marine carbon, nitrogen, and oxygen cycles with prescribed or prognostic atmospheric CO2 concentration. A series of experiments covering the historical period (1850–2014) were performed following the DECK (Diagnostic, Evaluation and Characterization of Klima) and CMIP6 (Coupled Model Intercomparison Project 6) protocols. Overall, modelled biogeochemical tracer distributions and fluxes, transient evolution in surface air temperature, air–sea CO2 fluxes, and changes in ocean carbon and heat contents are in good agreement with observations. Modelled inorganic and organic tracer distributions are quantitatively evaluated by statistically derived metrics. Results of the FOCI-MOPS model, including sea surface temperature, surface pH, oxygen (100–600 m), nitrate (0–100 m), and primary production, are within the range of other CMIP6 model results. Overall, the evaluation of FOCI-MOPS indicates its suitability for Earth climate system simulations.

S/SE Brazilian continental margin sea surface temperature and productivity changes over the last 50 kyr

Off the S/SE Brazilian continental margin, the Brazil Current (BC) drives important oceanographic processes. Over the Deglacial time interval, this shallow current was influenced by the Atlantic Meridional Overturning Circulation (AMOC) at different timescales resulting in changes in sea surface temperature (SST) and primary productivity. In this work, a 50-kyr record retrieved from the upper slope of Santos Basin (NAP63–1, 24°30′10“ S, 44°11’28” W, 842 m) was utilized to evaluate SST and productivity changes based on planktonic foraminifera abundances and Globigerinoides ruber (albus) Mg/Ca ratios. Our results highlight that during Marine Isotopic Stage 3 (MIS 3), the SW Atlantic was marked by increased variability in SST and productivity related to South Atlantic Central Water upwelling during BC strengthening driven by episodic AMOC interruption events. As the AMOC weakened during MIS 2, the BC strengthened, and surface water productivity increased in the Brazilian margin. Towards MIS 1, SST progressively increased while productivity decreased because of a weaker BC as AMOC resumed its interglacial state. Our findings suggest that the previously observed Holocene antiphase relationship between AMOC and BC has been present since MIS 3.

Seascape genomics of common dolphins (Delphinus delphis) reveals adaptive diversity linked to regional and local oceanography

BackgroundHigh levels of standing genomic variation in wide-ranging marine species may enhance prospects for their long-term persistence. Patterns of connectivity and adaptation in such species are often thought to be influenced by spatial factors, environmental heterogeneity, and oceanographic and geomorphological features. Population-level studies that analytically integrate genome-wide data with environmental information (i.e., seascape genomics) have the potential to inform the spatial distribution of adaptive diversity in wide-ranging marine species, such as many marine mammals. We assessed genotype-environment associations (GEAs) in 214 common dolphins (Delphinus delphis) along > 3000 km of the southern coast of Australia.ResultsWe identified 747 candidate adaptive SNPs out of a filtered panel of 17,327 SNPs, and five putatively locally-adapted populations with high levels of standing genomic variation were disclosed along environmentally heterogeneous coasts. Current velocity, sea surface temperature, salinity, and primary productivity were the key environmental variables associated with genomic variation. These environmental variables are in turn related to three main oceanographic phenomena that are likely affecting the dispersal of common dolphins: (1) regional oceanographic circulation, (2) localised and seasonal upwellings, and (3) seasonal on-shelf circulation in protected coastal habitats. Signals of selection at exonic gene regions suggest that adaptive divergence is related to important metabolic traits.ConclusionTo the best of our knowledge, this represents the first seascape genomics study for common dolphins (genus Delphinus). Information from the associations between populations and their environment can assist population management in forecasting the adaptive capacity of common dolphins to climate change and other anthropogenic impacts.

The impact of climate variables on marine fish production: an empirical evidence from Bangladesh based on autoregressive distributed lag (ARDL) approach.

Several studies have highlighted the significant impact of climate change on agriculture. However, there have been little empirical enquiries into the impact of climate change on marine fish production, particularly in Bangladesh. Hence, this study aims to investigate the impact of climate change on marine fish production in Bangladesh using data from 1961 to 2019. Data were obtained from the Food and Agriculture Organization, Bangladesh Meteorological Department, the World Development Indicators, and the National Oceanic and Atmospheric Administration. The autoregressive distributed lag (ARDL) model was used to describe the dynamic link between CO2 emissions, average temperature, Sea Surface Temperature (SST), rainfall, sunshine, wind and marine fish production. The ARDL approach to cointegration revealed that SST (β = 0.258), rainfall (β =0.297), and sunshine (β =0.663) significantly influence marine fish production at 1% and 10% levels in the short run and at 1% level in the long run. The results also found that average temperature has a significant negative impact on fish production in both short and long runs. On the other hand, CO2 emissions have a negative impact on marine fish production in the short run. Specifically, for every 1% rise in CO2 emissions, marine fish production will decline by 0.11%. The findings of this study suggest that policymakers formulate better policy frameworks for climate change adaptation and sustainable management of marine fisheries at the national level. Research and development in Bangladesh's fisheries sector should also focus on marine fish species that can resist high sea surface temperatures, CO2 emissions, and average temperatures.