The Distributional Characteristics of Heavy Metal in Jiangsu Province Shoal Sea

After the analysis of surface samples and core samples collected in Xinyanggang tidal land, the contents of Pb, Cu, Zn, and Cr were obtained and analyzed in this paper. The heavy metal accumulation rule and pollution status were studied by Index of geo-accumulation, latent ecological risk index method, and elements accumulation index method. The research suggests that (1) the contents of heavy metal Pb, Cu, Zn, and Cr in Xinyanggang tidal land have the same change trend, and such trend remains unchanged after the data were normalized, while the fluctuation range becomes smaller. (2) After analyzing the heavy metal content in the surface samples, it was revealed that the contents of heavy metals are getting lower from high tidal zone to low tidal zone, but the ranges of the change were different. Cu, Ni, and Zn emerge obvious decline from supratidal zone to subtidal zone, while the changes of Cr and Pb are not obvious. (3) Pb and Cr contents in Xinyanggang tidal land present accumulative character, as Pb in Xinyanggang is 3 times as much as the local background value, whose EF reaches 3.774. (4) RI value in Xinyanggang is 23.552, which indicates that though Xinyanggang tidal land has some heavy metal pollution and accumulation, there are no ecosystem risks, and the whole Xinyanggang core area environment quality is relatively good

Air-water exchange and distribution pattern of organochlorine pesticides in the atmosphere and surface water of the open Pacific ocean

Surface seawater and lower atmosphere gas samples were collected simultaneously between 18°N and 40°S in the open Pacific Ocean in 2006–2007. Samples were analyzed for organochlorine pesticides (OCPs) to assess their distribution patterns, the role of ocean in the long-range transport (LRT), and the air-water exchange directions in the open Pacific Ocean. Such open ocean studies can yield useful information such as establishing temporal and spatial trends and assessing primary vs secondary emissions of legacy OCPs. Target compounds included hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and its derivatives, and chlordane compounds. Concentrations for α-HCH, γ-HCH, trans-chlordane (TC), and cis-chlordane (CC) were higher in the Northern Hemisphere (NH) than the Southern Hemisphere (SH) in both gaseous and dissolved phases, while the distribution patterns of DDTs and heptachlor exo-epoxide (HEPX) showed a reversed pattern. In the N Pacific, concentrations of α-HCH and γ-HCH in the present work were lower by 63 and 16 times than those observed in 1989–1990. The distribution patterns of DDT suggested there was usage in the SH around 2006. Calculated fugacity ratios suggested that γ-HCH was volatilizing from surface water to the atmosphere, and the air-water exchange fluxes were 0.3–11.1 ng m−2 day−1. This is the first field study that reported the open Pacific Ocean has become the secondary source for γ-HCH and implied that ocean could affect LRT of OCPs by supplying these compounds via air-sea exchange

Rapid changes in heatwaves pose dual challenge in Eastern China and its adjacent seas

This paper performs a comparative analysis of the spatiotemporal variations of the statistical characteristics of both atmospheric heatwaves over the land (AHWs) in eastern China and marine heatwaves (MHWs) in adjacent seas using a unified heatwave definition. The multi-year average total days and frequency of MHWs during 1982-2019 were 5 and 2 times higher than those of AHWs, respectively, while the mean intensities of AHWs and MHWs were unchanged. The future frequency and duration of AHWs will continue to increase, leading to a superimposed increase in AHW total days. The decreasing frequency and increasing duration of MHWs will result in nearly year-round MHWs from 2060. Under the control of high-pressure systems, clear skies dominate the summer weather conditions in eastern China and its adjacent seas, which will trigger heatwaves. Heatwaves in turn can release substantial ocean latent heat. Enhanced convection and heating will further drive a stronger anticyclone over the western North Pacific, leading to a stronger and more westwardextending western North Pacific subtropical high (WNPSH). Moreover, super El Niño can promote an anomalous WNPSH in decaying summer, which may cause more serious heatwaves. The multi-year average persons affected by AHWs (PAHWs) during 1982-2019 were larger in the North China Plain, Yangtze River Delta, and Sichuan Basin with the regional sum exceeding 3 million. The future maximum PAHWs under SSP2-4.5 and SSP5-8.5 scenarios will be 3.9 billion in 2076 and 4.7 billion in 2085, respectively. Marine ecosystems like artificial ranches and coral reefs will be more threatened by longerlasting MHWs

Provenance Discrimination of Siliciclastic Sediments in the Western Sea of Japan over the Past 30 kyr: Evidence from Major, Trace Elements, and Pb Isotopes

AbstractThe Sea of Japan (JS), a unique marginal sea without any large river influxes in the western Pacific, provides ample information about the evolution of sea level, East Asian monsoons (EAM), sea ice activity, and ocean currents in geological time. However, insufficient investigation in the western JS limits our knowledge of East Asian climate change. This study utilizes major and trace elements and Pb isotopes of fine siliciclastic components (<63 μm) of core LV53-18-2 and determines the provenances using statistical methods and discrimination diagrams. The results show that the terrigenous debris of LV53-18-2 was mainly composed of aeolian dust from northeast China, ice-rafted debris (IRD), and volcanic materials from the Far East coast over the last 30 kyr. During the late last glacial period, sea ice activity carried weakly weathered IRD to the study area. Meanwhile, the strengthened East Asian winter monsoon (EAWM) brought dust from northeast China to the study site owing to the cold climate and enlarged sandy land. During the late last deglacial period to early Holocene (15-8 kyr), ascending boreal summer insolation drove the intense melting of sea ice. This led to the deposition of large amounts of weakly weathered IRD and remarkably influenced the chemical composition of the core. After 8 kyr, the global sea level rose to -15 m below the modern sea level and opened the Tatar Strait. Consequently, freshwater supplied by the Amur River entered the JS and gave birth to the Liman Cold Current (LCC), which transported more mafic materials from the Kema terrane upstream

Rapid changes in heatwaves pose dual challenge in Eastern China and its adjacent seas

This paper performs a comparative analysis of the spatiotemporal variations of the statistical characteristics of both atmospheric heatwaves over the land (AHWs) in eastern China and marine heatwaves (MHWs) in adjacent seas using a unified heatwave definition. The multi-year average total days and frequency of MHWs during 1982-2019 were 5 and 2 times higher than those of AHWs, respectively, while the mean intensities of AHWs and MHWs were unchanged. The future frequency and duration of AHWs will continue to increase, leading to a superimposed increase in AHW total days. The decreasing frequency and increasing duration of MHWs will result in nearly year-round MHWs from 2060. Under the control of high-pressure systems, clear skies dominate the summer weather conditions in eastern China and its adjacent seas, which will trigger heatwaves. Heatwaves in turn can release substantial ocean latent heat. Enhanced convection and heating will further drive a stronger anticyclone over the western North Pacific, leading to a stronger and more westwardextending western North Pacific subtropical high (WNPSH). Moreover, super El Niño can promote an anomalous WNPSH in decaying summer, which may cause more serious heatwaves. The multi-year average persons affected by AHWs (PAHWs) during 1982-2019 were larger in the North China Plain, Yangtze River Delta, and Sichuan Basin with the regional sum exceeding 3 million. The future maximum PAHWs under SSP2-4.5 and SSP5-8.5 scenarios will be 3.9 billion in 2076 and 4.7 billion in 2085, respectively. Marine ecosystems like artificial ranches and coral reefs will be more threatened by longerlasting MHWs

Rapid changes in heatwaves pose dual challenge in Eastern China and its adjacent seas

This paper performs a comparative analysis of the spatiotemporal variations of the statistical characteristics of both atmospheric heatwaves over the land (AHWs) in eastern China and marine heatwaves (MHWs) in adjacent seas using a unified heatwave definition. The multi-year average total days and frequency of MHWs during 1982-2019 were 5 and 2 times higher than those of AHWs, respectively, while the mean intensities of AHWs and MHWs were unchanged. The future frequency and duration of AHWs will continue to increase, leading to a superimposed increase in AHW total days. The decreasing frequency and increasing duration of MHWs will result in nearly year-round MHWs from 2060. Under the control of high-pressure systems, clear skies dominate the summer weather conditions in eastern China and its adjacent seas, which will trigger heatwaves. Heatwaves in turn can release substantial ocean latent heat. Enhanced convection and heating will further drive a stronger anticyclone over the western North Pacific, leading to a stronger and more westward-extending western North Pacific subtropical high (WNPSH). Moreover, super El Niño can promote an anomalous WNPSH in decaying summer, which may cause more serious heatwaves. The multi-year average persons affected by AHWs (PAHWs) during 1982-2019 were larger in the North China Plain, Yangtze River Delta, and Sichuan Basin with the regional sum exceeding 3 million. The future maximum PAHWs under SSP2-4.5 and SSP5-8.5 scenarios will be 3.9 billion in 2076 and 4.7 billion in 2085, respectively. Marine ecosystems like artificial ranches and coral reefs will be more threatened by longer-lasting MHWs

Marine Heatwaves in China's Marginal Seas and Adjacent Offshore Waters: Past, Present, and Future

Under the combined impacts of natural changes and human activities, the past, current, and future marine heatwaves (MHWs) in China's marginal seas and adjacent offshore waters (CMSOW) need a comprehensive understanding. This study provides a systematic analysis of the spatiotemporal variations using daily sea surface temperature data and simulates the future trend using 12 climate models. During 1982–2018, the mean annual total days, duration, frequency, and mean intensity of the MHWs in the CMSOW increased by 20–30 days/decade, 5–9 days/decade, 1–2 decade−1, and 0.1–0.3°C/decade, respectively (p <0.01). The maximum sea surface temperature anomalies in the Bohai Sea was over 6–8°C, and the MHW's frequency, duration, and mean intensity were higher than twice the global average, which could have impacted fishery resources and occurrence of harmful algal blooms. The variations of the MHWs in the CMSOW result from the robust ocean surface warming, which is caused by increased solar radiation due to reduced cloud cover, reduced ocean heat loss from weaker wind speed, weakening but warmer Kuroshio, and strong El Niño. In the future, the areas with longer total days and duration will increase; the spatial pattern of frequency has a negative relationship with that of duration while that of mean intensity is mostly unchanged. Year 2040 is a key node for the future changes of MHW under different Representative Concentration Pathways. The trend of total days increases from fast to slow, and frequency shows an opposite trend; the duration and mean intensity rise faster after 2040.National Natural Science Foundation of China-Yunnan Joint Fund6 month embargo; first published online 21 February 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Pollution status and trophic transfer of polycyclic aromatic hydrocarbons in coral reef ecosystems of the South China Sea

Coral reef ecosystems are important fishing grounds in tropical and subtropical areas and have been widely contaminated by chemicals. However, the current understanding of the pollution status and trophic transfer of exogenous chemicals in coral reef ecosystems is still limited. This study aims to characterize the occurrence of 16 priority polycyclic aromatic hydrocarbons (PAHs) in sediments, corals, and other biotas in the trophic-complex coral reef ecosystems in the Xisha and Nansha Islands of the South China Sea. PAH transfer characteristics in the highly diverse coral reef food webs were analyzed through stable isotope ratios and trophic magnification factors (TMFs). PAHs were observed in sediment and biota samples of both Xisha and Nansha coral reef ecosystems. The TMFs ranging from 0.46 to 2.18 for the Xisha food web indicate limited trophic transfer of PAHs, while those ranging from 1.07 to 5.25 for the Nansha food web indicate trophic magnification of PAHs. The octanol-water partition coefficient (Kow) of PAHs may positively influence the PAH biomagnification via accumulation along the trophic levels. This study provides new insights into PAH contamination patterns and their trophodynamic behaviour in highly diverse coral reef ecosystems, which can serve as a scientific basis for ecological risk assessment, biodiversity conservation, and coastal function management in global coral reef systems

DataSheet_1_Rapid changes in heatwaves pose dual challenge in Eastern China and its adjacent seas.pdf

This paper performs a comparative analysis of the spatiotemporal variations of the statistical characteristics of both atmospheric heatwaves over the land (AHWs) in eastern China and marine heatwaves (MHWs) in adjacent seas using a unified heatwave definition. The multi-year average total days and frequency of MHWs during 1982-2019 were 5 and 2 times higher than those of AHWs, respectively, while the mean intensities of AHWs and MHWs were unchanged. The future frequency and duration of AHWs will continue to increase, leading to a superimposed increase in AHW total days. The decreasing frequency and increasing duration of MHWs will result in nearly year-round MHWs from 2060. Under the control of high-pressure systems, clear skies dominate the summer weather conditions in eastern China and its adjacent seas, which will trigger heatwaves. Heatwaves in turn can release substantial ocean latent heat. Enhanced convection and heating will further drive a stronger anticyclone over the western North Pacific, leading to a stronger and more westward-extending western North Pacific subtropical high (WNPSH). Moreover, super El Niño can promote an anomalous WNPSH in decaying summer, which may cause more serious heatwaves. The multi-year average persons affected by AHWs (PAHWs) during 1982-2019 were larger in the North China Plain, Yangtze River Delta, and Sichuan Basin with the regional sum exceeding 3 million. The future maximum PAHWs under SSP2-4.5 and SSP5-8.5 scenarios will be 3.9 billion in 2076 and 4.7 billion in 2085, respectively. Marine ecosystems like artificial ranches and coral reefs will be more threatened by longer-lasting MHWs.</p