Warm Currents Research Articles

Some genera and species of dissepimented solitary Rugosa (Anthozoa) from the Pennsylvanian (Carboniferous) and Cisuralian (Permian) of North America. Part 1. Yuanophylloides Fomichev, 1953

Several specimens derived from the Missourian (Pennsylvanian) deposits of the Glass Mountains (SW Texas, USA) are identified as Yuanophylloides Fomichev, 1953. Some species that earlier authors included in the genera Campophyllum Milne-Edwards and Haime, 1852, Bothrophyllum Trautschold, 1879, and Neokoninckophyllum Fomichev, 1939 are re-identified as belonging to Yuanophylloides. In addition to the type genus, a new subgenus Patulaxis of Yuanophylloides with the type species Y. (P.) molestus sp. nov. and the new species Y. (P.) parcus and Y. (P.) laxus are introduced. Re-identification of the upper Serpukhovian Campophyllum kansasense Miller and Gurley, 1893 as Yuanophylloides renders untenable the origin of that genus in the Donets Basin. The circum- Laurussia warm current is suggested as having carried Yuanophylloides larvae from the North American superprovince to the Paleotethyan superprovince. This genus supplements the group of genera suggested by Fedorowski (2023) as having originated in the North American superprovince and migrating to the Paleotethyan superprovince. Together, these genera demonstrate the importance of taxonomic investigation to establish paleobiogeography as a constrain on global (i.e., tectonic scale) environmental reconstructions.

The East China Sea Kuroshio Current Intensifies Deep Convective Precipitation: A Case Study

AbstractDeep atmospheric convection is often observed over the Kuroshio in the East China Sea (ECSK). However, the mechanisms by which warm oceanic currents fuel transient deep convection are not fully understood. This study investigates an atmospheric cold front that brought heavy precipitation as it traversed the ECSK in April 2004. The southwesterlies ahead of the cold front advected moist and warm air, creating a zone with high convective available potential energy (CAPE) values. As the cold front approached the ECSK, the pre‐frontal high CAPE values coalesced with those over the warm current that substantially strengthened the deep convection, with precipitation rate increasing from 3 mm hr−1 to 10 mm hr−1. A numerical model well simulated the marked increase in precipitation over the ECSK, permitting the isolation of the ECSK's influence by contrasting the control (CTRL) run with an experiment with smoothed sea surface temperatures (SMTH run). Results show the ECSK contributed to 46% of the precipitation over the warm current. The ECSK was found to amplify ascending motion and elevate neutral buoyancy levels, extending its effect up to the tropopause. Furthermore, the strengthened deep convection significantly lowered the sea level pressure (SLP) over the ECSK and impressed upon the time‐mean SLP field. An additional experiment with lowered SST underscored the high SST's critical role in deep convection. This case study suggests a novel pathway by which the effects of warm oceanic currents influence the upper troposphere under extreme conditions with strong baroclinic instability.

1500-Year Sedimentary Records of the East Asian Summer Monsoon and Yellow Sea Warm Current from the Muddy Area of the North Yellow Sea, China

Advances in reconstructing the East Asian monsoon have provided important insights into the natural climate variability in Asia during the pre-instrumental period. However, there are still unresolved paleoclimate issues that necessitate the use of geological proxy data to further our understanding of past climate changes. This study focused on core B13, located in the muddy area of the North Yellow Sea (NYS), to investigate the evolutionary history over the past 1500 years and reconstruct the records of the East Asian summer monsoon (EASM) and Yellow Sea warm current (YSWC). The mean grain size of sediment ranged from 4.2 Φ to 5.6 Φ, with the sorting coefficient ranging from 1.9 to 2.2, indicating poor sorting. The C–M pattern showed a limited range of values, with the M values being between 33 and 83 μm and the C values being between 165 and 287 μm, suggesting uniform-suspension transport. The L* index ranged from 40.41 to 44.12, while the a* and b* indexes ranged from 0.55 to 1.78 and 2.86 to 5.94, respectively. A stable and relatively strong sedimentary environment is indicated through a comprehensive analysis of the C–M plot, triangular plot, the relationship between the mean grain size and sorting, and the changes in grain-size and color parameters. The sedimentary evolution in the muddy area of the NYS over the past 1500 years can be categorized into three distinct stages. In this study, proxies for the EASM and YSWC were extracted using the VPCA method from the sediment grain size and diffuse spectral reflectance (DSR) data, respectively. The reliability of these proxies has been confirmed through comparison with other validated proxies. The results indicated that the strength of the EASM and YSWC also exhibited three stages, corresponding to the Dark Ages Cold Period (DACP), Medieval Warm Period (MWP), and Little Ice Age (LIA), respectively. On a centennial scale, the correlation between the EASM and YSWC was predominantly negative. This research validates the reliability of the VPCA method for paleoclimate reconstruction, contributes important climate records in a special muddy area, and provides a new perspective on how to eliminate temporal errors in verifying the correlation between the two climate systems.

Microplastic Distribution Characteristics Considering the Marine Environment Based on Surface Seawater Quality Parameters in Southern Sea of Korea, 2019

The present study determined the microplastic distributions in the surface water of the Southern Sea of Korea (SS01–SS09) in September 2019, depending on three groups (Groups A, B, and C) categorized via the principal component analysis and cluster analysis using the water quality parameters (water temperature, salinity, pH, dissolved oxygen, suspended particulate matter, and chlorophyll-a). The microplastic samples in the surface water were collected using a 300 μm-mesh neuston net. The microplastic abundance ranged from 0.10 to 5.08 (average 0.71 ± 1.64) particles/m3 in the entire sampling area. Median values in Groups A (SS01, SS02, and SS07), B (SS05, SS08, and SS09), and C (SS03, SS04, and SS06) were 0.14 ± 0.02, 0.12 ± 0.14, and 0.17 ± 2.85 particles/m3, respectively, and there were no statistically significant differences (p < 0.050). However, it was highlighted that the most considerably numerous microplastic abundance in SS04 (5.08 particles/m3) revealed relatively high water temperatures distinguished from other sampling areas. Polystyrene, consisting mainly of expanded polystyrene, was the predominant polymer type, accounting for 81.5% in Groups A, 84.4% in B, and 97.0% in C. The particle size in Group C (average 3.11 ± 1.08 mm) was statistically larger (p < 0.001) than those of Groups A (average 0.71 ± 1.06 mm) and B (average 0.98 ± 1.22 mm). Only fragment and sheet shapes were found in all the sampling points and the former, which consisted of the secondary microplastics regardless of the groups, was the dominant type. The fragment composition gradually increased from 77.3% in Group A, 96.7% in B, to 99.1% in C. However, the strategy studies should be investigated in the foreseeable future to supplement the current study limitations, such as verifying the effect of the Yangtze River and the Tsushima warm current, and seasonal fluctuation.

Seasonal Phytoplankton Characteristics Related with Region-Specific Coastal Environments in the Korean Peninsula

The seasonal dynamics of phytoplankton communities in Korean coastal waters (KCWs) are influenced by complex interactions between ocean currents and nearshore human activities. Despite these influences, the understanding of seasonal phytoplankton changes and their environmental relationships in KCWs remains limited. We investigate the influence of the distinct characteristics of the three seas surrounding the KCWs (the Yellow Sea, the South Sea, and the East Sea) on seasonal phytoplankton communities based on field surveys conducted at 23 stations between 2020 and 2021. The East Sea exhibited higher winter temperatures due to the Jeju and Tsushima warm currents, while summer temperatures were lower compared to the other regions, highlighting the role of currents and deeper oceanic waters. The Yellow Sea showed significant freshwater influence with low salinity levels from major rivers, contrasting with the higher salinity in the East Sea. These differences led to a disparity in the productivity of the two regions: the highest value of Chl. a was observed to be 6.05 µg L–1 in the Yellow Sea in summer. Diatoms dominated in nutrient-rich conditions, particularly in the Yellow Sea, where they comprised up to 80–100% of the phytoplankton community in summer, winter, and spring. PCA analysis revealed positive correlations between diatoms and Chl. a, while cryptophytes, which thrive in the absence of diatom proliferation, showed no such correlation, indicating their opportunistic growth in nutrient-limited conditions. This study highlights the significant impact of region-specific hydrographic factors on phytoplankton communities in KCWs, with diatoms dominating in summer and cryptophytes and dinoflagellates showing seasonal and regional variations. Understanding these dynamics is crucial for predicting phytoplankton bloom dynamics and their ecological implications in coastal ecosystems.

Sedimentary provenance and paleoenvironmental evolution since the Last Glacial Maximum off the Xisha Platform, northern South China Sea

The complexity of retrieving paleoenvironmental variability from hemipelagic sedimentary archives in the marginal seas has been exacerbated by intricate interactions between sedimentary sources and climatic fluctuations, modulated by sea-level shifts and oceanic currents. These challenges are particularly pronounced in the northern South China Sea (SCS). This study introduces new data, incorporating SrNd isotopic, clay minerals, grain-size, and calcareous nannofossil proxies, to assess the sedimentary provenance and paleoenvironmental changes in the northwestern SCS since the Last Glacial Maximum. The sedimentary provenance highlights the primary source from the northern SCS, particularly the Red River drainage system, with potential contributions from the Indochina drainage systems. The combined analysis of multiple proxies suggests that sedimentary processes and biotic activity in the examined core were mainly influenced by sea-level fluctuations, concerning global ice dynamics. Variations of grain sizes and kaolinite / (illite + chlorite) (K/(I + C)) ratio largely correspond to the terrestrial flux variation from northern SCS associated with sea-level changes during glacial-interglacial cycles. Furthermore, the smectite / (illite + chlorite) (S/(I + C)) ratio in this study appears to have been primarily influenced by the activity of the Kuroshio current in the northern SCS. The possible interference of intensified northeastward warm currents during relatively warm intervals caused the depletion of the S/(I +C) ratio and was responsible for the depletion of soluble calcareous nannofossils. Additionally, this study deduces that sedimentary processes and biotic activity in the northern SCS, in response to mainly sea-level changes and surface currents, were largely controlled by global ice dynamics and solar radiation. This study also underscores the need for further interdisciplinary research, combining various proxies, to enhance our understanding of paleoenvironmental assessments in hemipelagic sediments in marginal seas.

Research on the effects of ocean current on nuclear wastewater in Japan

According to reports, the Fukushima Daiichi Nuclear Power Station nuclear pollution water drainage project has been completed. Subsequently, Tokyo Electric Power will directly discharge nuclear wastewater into the ocean through a subsea tunnel connecting the land. These nuclear wastewater will be discharged to the waters near the Tropic of Cancer, which is greatly affected by the Japanese warm current, and nuclear wastewater will be taken around the world through ocean currents. German research institutions point out that within a month from the date of discharge of Fukushima nuclear wastewater, its radioactive material will spread to most of the Pacific Ocean, which will seriously affect global fish migration, ocean fisheries, human health and ecological security. Due to the impact of the global ocean current, China's East China Sea, the Yellow Sea and the Bohai Sea will also be affected by nuclear waste water pollution. Based on this, this text will start from the impact of the El Nino warm current on the flow of nuclear wastewater, and will soon explain the impact of Japan's dumping of nuclear wastewater on global security, and from a personal perspective on the current view of environmental protection and governance.

Early Transport Patterns and Influencing Factors of Different Stocks of Uroteuthis edulis in the East China Sea.

Uroteuthis edulis (U. edulis) is an important economic loliginid resource in the East China Sea (ECS). Its flexible life history traits enable the population to quickly adapt to changes in habitat. Understanding the early transport process helps us to grasp the habitat requirements of populations at key life history stages. In this study, particle tracing was used to simulate the early transport trajectories (within 120 days). The gradient forest method (GFM) and generalized additive mixed models (GAMMs) were used to analyze the key environmental variables that affect the early transport trajectories and the impact of environmental factors on the transport process, respectively. The results showed that spring stock tracers were transported to the northeast of the release area (Pengjiayu water) and the Pacific side of Japan. Summer stock tracers were transported to the north and northeast of the release area (Zhoushan island). Current velocity, salinity, and temperature were key environmental variables that affected the trace element ratios of spring stock at early life history stages. Mixed-layer depth (MLD), velocity, and chlorophyll a concentration (Chla) were key environmental variables for summer stock. Zonal velocity was positively correlated with the trace element ratio for spring and summer stock (0.14-0.16 m/s), while the meridional velocity showed an opposite correlation. The physical driving mechanisms of the Kuroshio warm current (or the Taiwan warm current) and the Yangtze River determine the paralarva retention location during early transportation. The differences in the dominant factors of the water environment in the retention area may affect the paralarva physiological functions and food availability. This study provides a scientific basis for a comprehensive understanding of the migration characteristics of U. edulis with different stocks.

Fish fauna and environmental factors in river estuaries of small and medium-sized rivers on islands significantly influenced by warm currents.

River estuaries are influenced by terrestrial and marine areas, and have a unique environment that is constantly fluctuating. They are also important habitats for biodiversity conservation. Tanegashima Island is significantly influenced by the Kuroshio Current. Although nearby Yakushima Island has been recognized as a World Natural Heritage site and information on many species has been collected, there is little information on species inhabiting the river estuaries of Tanegashima Island. In this study, the river estuarine ichthyofauna of 26 small and medium-sized rivers on Tanegashima Island was surveyed and a total of 2758 individuals of 29 species and one genus belonging to 15 families were collected. The fish fauna of the river estuaries of Tanegashima Island were classified into three groups, namely the river estuaries where coastal terraces are underdeveloped and drowned valleys are formed, the river group where the riverbed gradient at the mouth is high, and other river groups. Environmental factors selected as being important for ordination of fish fauna were the altitude of the headstreams at the watershed scale, the gradient of the river estuarine area, and the presence or absence of rapids in the estuary. The importance of the geohistorical factor of drowned valley formation, in addition to habitat and watershed scale environmental factors, as a factor on river estuarine fish fauna is an important finding for future conservation of local biota diversity.

A trawl collected dataset of Johnius (Actinopterygii, Sciaenidae) species in central-western Taiwanese waters.

Sciaenidae is one of the most important coastal fisheries in Taiwan, both in production and economic value. It is also significant as the main targetted diet of Chinese white dolphins, Sousachinensis, especially for the genus Johnius, such as J.taiwanensis, J.belangerii and J.distinctus, which is primarily found in central-western Taiwan coastal waters. Despite an abundance of Johnius species occurrences reported in the Global Biodiversity Information Facility (GBIF) and the Taiwan Biodiversity Information Facility (TaiBIF) data portals (Mozambique, Australia, Taiwan, Korea, India, Indonesia, South Africa, Pakistan, Vietnam and China), there are no specific datasets that properly document the regional distribution of this genus, especially in Taiwanese waters. Thus, this paper describes a dataset of genus Johnius occurrences in waters on the central-western coast of Taiwan. The data collection for the present study was conducted from 2009 until 2020 and comprised 62 sampling events and 133 occurrence records. All fish specimens were collected by trawling in Miaoli, Changhwa and Yunlin Counties, Taiwan and brought back to the lab for identification, individual number count and body weight measurement. These processing data have been integrated and established in the Taiwan Fish Database and published in GBIF. This dataset contains six Johnius species and 2,566 specimens, making it comprehensive Johnius fish fauna and spatial distributional data on the coastal habitat in central-western Taiwanese waters. This dataset contains 133 occurrence records of Johnius species (Sciaenidae) with 2,566 specimens, making it the most extensive public dataset of Johnius distribution records in Taiwan. The publication of this dataset through the TaiBIF and GBIF dataset platforms demonstrated that the number of Johnius spatial and temporal records in Taiwan waters is influenced by the topographical structure of the Changyun Rise (CYR) in combination with the cold current of the China Coastal currents and bound with the warm currents of the Kuroshio and the South China Sea on the central-western coast of Taiwan. The data serve as the foundation for understanding the biogeography and Johnius species ecology in Taiwan's coastal waters, which present a 2°C water temperature difference split at the CYR.

Talus and its cooling effects on the thermal regime of permafrost: A review

AbstractTalus, as the product of movement and accumulation along the slope after the cracking of cliffs or steep rock walls, is a common landform in the mountain periglacial environment. Significant thermal anomalies within talus have been widely reported to be a result of cooling effects. During the cold season, the increased temperature difference between talus and the ambient environment strengthens the intensity of convection (vertical flows) and transforms into upward advection (lateral flows) and exhausts the internal warm current. During the warm season, heat is concentrated on the surface of the talus, and the internal dominant cold current moves downward along the slope by advection. The principle of the proactive cooling effects of talus has been widely utilized in railway construction within permafrost regions as embankments to alleviate degradation of the underlying permafrost. However, limited model studies have examined the cooling effects of blocky debris in nature, and in situ observations are rare. Therefore, it will be important to increase observations and develop process‐based models that couple heat conduction, convection/advection, water transfer processes, and even the latent heat of phase change. This will help to better understand the extent of the cooling effects and its impact on the thermal regime of permafrost.

Spatial and Temporal Characteristics of Winter Diel Vertical Migration of Zooplankton and Nekton in the East China Shelf Seas Based on Multi‐Frequency Echosounder

AbstractThe diel vertical migration (DVM) of plankton and nekton plays an important role in the energy flow and material cycling of marine ecosystems. Especially in shelf seas, seasonal environmental variations may distinguish DVM characteristics in winter mixed water from summer pattern. Therefore, to investigate the patterns and influencing factors of winter DVM in East China Shelf Seas (ECSS), we carried out comprehensive research based on high‐resolution multi‐frequency acoustic data during the winter of 2019/2020. The results showed that: (a) acoustic and zooplankton sampling data can effectively capture the widely existence of winter DVM of different biological community in ECSS and their spatio‐temporal variabilities. (b) In East China Sea, the migration was mainly dominated by the Gas‐bearing class (GB), which had fast migration speed, compared to the Yellow Sea where the migration was dominated by the Fluid‐like class (FL). In addition, GB descends earlier than FL. (c) For large scale factors, during the full moon, the GB will aggregate deeper and the FL shallower, compared to the new moon, and regional temperature is an important factor affecting the distribution of organisms at meridional direction; for small scale processes, cold and warm currents and ocean fronts can also affect migration behavior. In the muddy area with full moon and spring tide, GB and FL show different inconsistent migration compared to normal relatively consistent pattern. These results will help us to better understand the physiological, ecological and environmental elements that control winter DVM, facilitating the management of ecosystem‐based fisheries resources.

Analysis of Spatiotemporal Variations and Influencing Factors of Sea Ice Extent in the Arctic and Antarctic

The 44 years (1979–2022) of satellite-derived sea ice extent in the Arctic and Antarctic reveals the details and new trends in the process of polar sea ice coverage changes. The speed of Arctic sea ice extent reduction and the interannual difference significantly increased after 2004. Trend analysis suggests that the Arctic Ocean may experience an ice-free period around 2060. The maximum anomaly of Arctic sea ice extent has gradually transitioned from September to October, indicating a trend of prolonged melting period. The center of gravity of sea ice in the Arctic Ocean is biased towards the Pacific side, and the spatial distribution pattern of sea ice is greatly influenced by the Atlantic warm current. The dynamism of the sea ice extent on the Atlantic side is significantly greater than in other regions. Since 2014, the Antarctic sea ice extent has shifted from slow growth to a rapid decreasing trend; the sea ice extent reached a historical minimum in 2022, decreasing by 2.02 × 106 km2 compared to 2014. The Antarctic experiences seven months of ice growth each year and five months of ice melting period, the annual change patterns of sea ice extent in the Arctic and Antarctic are slightly different.

Interannual sea-level variation around mainland Japan forced by subtropical North Pacific wind and its possible impact on the Tsugaru warm current

Interannual sea-level variation around mainland Japan forced by subtropical North Pacific wind and its possible impact on the Tsugaru warm current

Local-scale circulation associated with enhanced poleward moisture transport for Meiyu-Baiu heavy rainfall over western Japan

Heavy rainfall events in western Japan during early July have become more frequent, yet the underlying mechanism behind this trend during the late stage of the Meiyu-Baiu rainy season remains unclear. Our long-term analysis of short-duration events revealed that a quasi-stationary Rossby wave train enhances the poleward transport of moisture from the western Pacific, contributing to the frequent occurrence of heavy rainfall events over western Japan. The local-scale circulation over the East China Sea plays a substantial role in producing this quasi-stationary Rossby wave train, which is closely linked to enhanced deep convection over the Kuroshio warm current, characterized by a distinct sea surface temperature (SST) front. The coarse resolution of both the model and SST data may hinder the ability of climate simulations to capture the local-scale circulation, underscoring the importance of quasi-stationary atmospheric circulation for a better understanding of heavy rainfall events through poleward moisture transport.

Holocene sediment source analysis and paleoclimatic significance of core KZK01 from the eastern part of the Beibu Gulf

Identifying the sources of sediments is of great significance in reconstructing Holocene paleoclimate evolution in the Beibu Gulf and in understanding the characteristics of regional responses to changes in global climate. The Holocene paleoclimatic evolutionary history of the Beibu Gulf was investigated by chronological, geochemical, and mineralogical means using the sediments of Core KZK01 from the eastern part of the Beibu Gulf. The rare earth element (REE) distribution curves, (Gd/Yb)N and (La/Yb)N discriminant diagram, and (Gd/Lu)N and ∑LREE/∑HREE discriminant diagram indicated that the detrital materials in the eastern part of the Beibu Gulf primarily originated from Hainan Island and its proximal sources, with considerable contributions from Taiwan and Pearl River materials. Source analysis of clay minerals showed that Luzon Island was the main source of smectite, followed by Hainan Island. Rivers in Taiwan were the main sources of illite in the study area, followed by the Red River. The Red River was the main contributor of chlorite, followed by the Pearl River. Kaolinite mainly originated from Hainan Island and Guangxi. Coastal currents, surface currents, and warm currents were the main drivers of material transport. Paleoclimatic variations since the Holocene in the Beibu Gulf were divided into three stages: 12–9 cal kyr BP, 9–1.3 cal kyr BP, and 1.3 cal kyr BP to the present. During different stages of climatic evolution, drought was often accompanied by cold and humidity coexisted with warmth, and cold-dry-warm-humid alternation is characterized by significant phases. The illite crystallinity clearly recorded the extreme cold events, such as Bond Events (except Bond6) and the Younger Dryas, and the change trend was essentially consistent with the regional climate record, reflecting the control of global climate change on the process of land–sea interaction in the tropical region. Furthermore, it highlights the great potential of illite crystallinity as a proxy indicator for reconstructing the surface chemical weathering processes of the region.

Seasonal dynamics of dissolved organic matter bioavailability coupling with water mass circulation in the South Yellow Sea

As a typical shelf-marginal sea, the South Yellow Sea (SYS) is significantly influenced by various factors such as land-based inputs and water mass movements, leading the complex biogeochemical processes of dissolved organic matter (DOM) to become highly dynamic. However, the bioavailability of dissolved organic matter (DOM) coupled with water mass circulation has not been accurately assessed, despite being crucial for understanding the source-sink pattern of organic carbon in marginal sea. In this study, four cruises were conducted in the SYS to analyze the spatial and temporal distribution characteristics of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and total dissolved amino acids (TDAA). Combined with the bioassay experiments, TDAA carbon normalized yield [TDAA (%DOC)] and TDAA degradation index (DIAA) were used as indicators to explore the bioavailability of DOM across different water masses. Results show that the DOC of the SYS exhibits higher average value in late autumn and early winter, and lower value in spring and summer due to the seasonal alternation of water mass and biological activities. The collective results indicate that DOM bioavailability is higher in the Changjiang River diluted water (CDW) and lower in the Yellow Sea warm current (YSWC) and the Yellow Sea cold water mass (YSCWM). Approximately 20 % of DON can be degraded in the YSCWM during autumn. Notably, although the YSCWM constitutes merely constitutes 10 % of the SYS volume, it stores 18.1 % dissolved inorganic nitrogen (DIN) and 23.9 % PO43− of total nutrients, indicating that the YSCWM is a significant nutrient reservoir within the SYS.

Quantifying the contribution of temperature, salinity, and climate change to sea level rise in the Pacific Ocean: 2005-2019

In recent decades, Pacific Ocean’s steric sea level anomaly (SSLA) has shown prominent patterns among global sea level variations. With ongoing global warming, the frequency and intensity of climate and sea level changes have increased, particularly in the tropical Pacific region. Therefore, it is crucial to comprehend the overall trends and mechanisms governing volumetric sea level changes in the Pacific. To accurately quantify the spatiotemporal evolution characteristics of density-driven sea level change in the Pacific Ocean (PO) from 2005 to 2019, we decomposed temperature and salinity into linear trends, interannual variations, seasonal variations, and residual terms using the STL (seasonal-trend decomposition based on loess) method. To evaluate the influence of ocean temperature, salinity, and climate change on density-driven sea level change and its underlying mechanisms, we decompose temperature as well as salinity changes through into the Heaving (vertical displacements of isopycnal surfaces) and Spicing (density-compensated temperature and salinity change) modes. The findings reveal an average steric sea level rise rate of 0.34 ± 0.16 mm/yr in the PO from 2005 to 2019. Thermosteric sea-level accounts for 82% of this rise, primarily due to seawater temperature rise at depths of 0-700 m caused by Heaving mode changes. Accelerated SSLA increase via the thermosteric effect has been connected to interactions between greater Ekman downwelling from surface winds, radiation forcing linked to global greenhouse gases, and changes in the Pacific warm currents triggered by El Niño-Southern Oscillation (ENSO) episodes. Although salinity is affected by the Subantarctic Mode Water (SAMW) and the Antarctic Intermediate Water (AAIW) in the southern Indian Ocean, however the significance of salinity in sea level change is little compared to the role played by thermocline shift. This study offers a substantial contribution to the field, providing robust data and technical support, and facilitating a deeper understanding of the mechanisms underlying the effects of temperature and salinity on sea level changes during periods of rapid climate change, thus enhancing the accuracy of future predictions regarding sea level rise.

Effects of climate change-induced water temperature changes on the distribution of tidal river fish fauna in the Japanese archipelago

Intense anthropogenic impacts in tidal rivers can cause habitat loss and ecosystem degradation. In addition, changes in water temperature associated with climate change are significantly impacting the distribution area of fish fauna within tidal rivers. In the present study, we used long-term fish fauna data to determine the relationship between climate change-induced increases in water temperature and changes in the distribution of fish species in tidal rivers in the Japanese archipelago. The distribution ranges of many subtropical and tropical fish species were found to move northward in areas affected by warm currents, suggesting further possible distributional dispersal in future. This study is the first to examine the nationwide distributional changes and future projections of fish fauna in tidal rivers. The results suggest that many subtropical and tropical fishes are expanding their distribution areas in tidal rivers and in coastal and estuarine areas.

ТУРБУЛЕНТНЫЕ ПОТОКИ ТЕПЛА НАД БАРЕНЦЕВЫМ И КАРСКИМ МОРЯМИ, МНОГОЛЕТНЯЯ ИЗМЕНЧИВОСТЬ СВЯЗЬ С ОБЩЕЙ ЦИРКУЛЯЦИЕЙ АТМОСФЕРЫ

The paper considers the spatial and temporal variability of sensible and latent heat fluxes over the Barents and Kara seas during 1979-2018 based on the ERA-Interim reanalysis data with a 6-hour resolution. It is shown that the localization of extreme turbulent fluxes over the past decades has not changed as compared to the middle and second half of the 20th century. It is revealed that the greatest spatial and temporal variability of the fluxes is observed in the southern and southwestern sectors of the Barents Sea. It is demonstrated that the winter values of the spatial variability of heat fluxes exceed the summer ones by 2-5 times, and annual total heat flux values in the Barents Sea are 3-5 times higher than in the Kara Sea. The study of the influence of the pressure field anomalies during different phases of the North Atlantic, Arctic, and Scandinavian oscillations on the intensity of turbulent fluxes showed that the area of warm currents of the Barents Sea is most sensitive to changes in the atmospheric circulation.