Drivers,Trends,and Patterns of Changing Vegetation-greenness in Nansha Islands,China from 2016 to 2022

Changes in vegetation status generally also represents changes in the ecological health of islands and reefs(IRs).However,studies are limited of drivers and trends of vegetation change of Nansha Islands,China and how they relate to climate change and human activities.To resolve this limitation,we studied changes to the Normalized Difference Vegetation Index(NDVI)vegetation-greenness index for 22 IRs of Nansha Islands during normal and extreme conditions.Trends of vegetation greenness were analyzed using Sen's slope and Mann-Kendall test at two spatial scales(pixel and island),and driving factor analyses were performed by time-lagged partial correlation analyses.These were related to impacts from human activities and climatic factors under normal(temperature,precipitation,radiation,and Normalized Difference Built-up Index(NDBI))and extreme conditions(wind speed and latitude of IRs)from 2016 to 2022.Results showed:1)among the 22 IRs,NDVI increased/decreased significantly in 15/4 IRs,respectively.Huayang Reef had the highest NDVI change-rate(0.48%/mon),and Zhongye Island had the lowest(–0.29%/mon).Local spatial patterns were in one of two forms:dotted-form,and degradation in banded-form.2)Under normal conditions,human activities(characterized by NDBI)had higher impacts on vegetation-greenness than other factors.3)Under extreme conditions,wind speed(R^(2)=0.2337,P<0.05)and latitude(R^(2)=0.2769,P<0.05)provided limited explanation for changes from typhoon events.Our results provide scientific support for the sustainable development of Nansha Islands and the United Nations‘Ocean Decade’initiative.

U-Pb zircon geochronology of basaltic pyroclastic rocks from the basement beneath the Xisha Islands in the northwestern South China Sea and its geological significance

As one of the micro-blocks dispersed in the South China Sea(SCS), the basement of the Xisha Islands has rarely been drilled because of the thick overlying Cenozoic sediments, which has led to a confused understanding of the pre-Cenozoic basement of the Xisha Islands. Well CK-1, a kilometer-scale major scientific drill in the Xisha Islands in the northwestern SCS, penetrated thick reefal limestone(0–888.4 m) and the underlying basement rocks(888.4–901.4 m). In this study, we present the zircon U-Pb ages of basement basaltic pyroclastic rocks from Well CK-1 in the Xisha Islands of the northwestern SCS to investigate the basement nature of the Xisha microblock. The basement of Well CK-1 consists of basaltic pyroclastic rocks on the seamount. The zircon grains yielded apparent ages ranging from ca. 2 138.9 Ma to ca. 36 Ma. The old group of zircon grains from Well CK-1 was considered to be inherited zircons. Two Cenozoic zircons gave a weighted mean 206Pb/238U age of(36.3 ± 1.1) Ma,Mean Squared Weighted Deviations(MSWD) = 1.2, which may represent the maximum age of the volcano eruption. The Yanshanian inherited zircons(116.9–105.7 Ma and 146.1–130.2 Ma) from Well CK-1 are consistent with the zircons from Well XK-1, indicating that the basement of Chenhang Island may be similar to that of Well XK-1. We propose that the Xisha micro-block may have developed on a uniform Late Jurassic metamorphic crystalline basement, intruded by Cretaceous granitic magma.

Using Circular Economics Strategies to Manage Tourism on Remote Islands:A SMART Approach

Circular economics theory offers destination managers of remote islands a solution-oriented approach to environmental sustainability. This paper examines the practical benefits of this theory that will support the development of a circular economy regarding sustainable island tourism (SIT). The aim of this paper is to inform discussions regarding the feasibility of applying a practice theory that emphasises changes in the behaviours across three segments, visitors, residents, and enterprises using SMART technologies. To achieve this objective, a SMART indicator system (SIS) was used to identify current practices that would support a circular economy (CE). The key innovation of this study is the creation of a proposed framework that may inform best practices for SIT in the future. The findings highlight the potential opportunity of evidenced-based planning to deliver a circular economy strategy (CES) for remote islands in the future. These insights can potentially impact the way that local authorities and destination managers approach the planning of tourism for six islands along the west coast of Ireland.

Fish Assemblage and Abundance Distribution in Nanji Islands Marine Nature Reserve in Relation to Season Change

The fishing survey station located in the warm waters of the East China Sea is one of the abundant fishery resources of waters;with a large number of economic fish breeding grounds and economic juvenile feeding grounds. Several fish species according to this bottom trawl survey results which appear in the annual survey from winter to autumn give us a total of 58 species, which have appeared throughout the year. But the vast majority of species appears only in certain seasons, according to the sea fish survey and based on seasonal migratory species or species mainly small endemic species. The survey of fish is tropical and subtropical warm water species and warm temperate species, and the history of the area has several types of 397 different species. There are many reasons, in addition to recent years, human disturbance and adverse consequences of environmental changes brought about, but also with the relevant sampling methods and sampler time, the survey sampled only trawl based, from Ping yang Ocean and Fisheries Bureau, the waters are still other jobs method net, gill nets, fishing industry, etc. Survey results show that the type of fish in the summer (58 species) > spring (55 species) > winter (51 species) > autumn (42 species). The type of season was among spring to summer rose, summer to autumn decline. The survey found that in the reef area of the Nanji Islands, no one species of fish is the dominant species throughout the year (according to the dominant species, each species is dominant only in one season). From the dominant species turnover accounting for the four seasons, in winter it has 53.72% of the total biomass or annual biomass, spring it has 41.53% of the overall biomass, summer it has 31.85% and autumn it has 38.56% of total biomass. Visible, seasonal succession of dominant species of fish phenomenon is very obvious, especially in the spring and winter, summer transfers dominate species at this stage show the greatest change, but winter, the transfer of this dominant species changes in minimal. Seasonal changes from biomass and the average annual marine fish survey biomass were 4832.25 g/h. From different seasons, the average biomass in winter (10779.88 g/h) > of the average biomass in spring (3624.1 g/hour) > of the mean biomass in autumn (3158 g/h) > the average Biomass in summer (1767 g/h). All of them show significant seasonal variation of the biomass, in winter and spring, the biomass is generally not high, but significantly higher than in the summer and autumn seasons. Each season, around the coast of southern Zhejiang, is less than the biomass and other catches off, which involves investigating sea location, size range, and the survey ship different network related tools. Another change from the area of biomass, some studies found that the survey of four-season fish of waters above the biological capacity of several kilograms only in some stations, namely stations and the highest biomass in summer appeared in stations 3, 7 and 11. In autumn the highest biomass appeared in stations 3, 6, 20 and 23.

Land-use change and windstorms legacies drove the recolonization dynamics of laurel forests in Tenerife, Canary islands

Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities.In the past,Canary laurel forests have been greatly altered by logging,livestock and agriculture.The remains of laurel forests are currently protected in the Canary Islands(Spain).However,we miss basic information needed for their restoration and adaptive management,such as tree longevity,growth potential and responsiveness to natural and anthropogenic disturbances.Using dendrochronological methods,we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island.Wood cores were collected from over 80 trees per stand at three stands per forest.We used ring-width series to estimate tree ages and calculate annual basal area increments(BAI),cumulative diameter increases,and changes indicative of released and suppressed growth.Twelve tree species were found in all stands,with Laurus novocanariensis,Ilex canariensis and Morella faya being the most common species.Although some individuals were over 100 years old,61.8%-88.9% of the trees per stand established between 1940 and 1970,coinciding with a post-war period of land abandonment,rural exodus and the onset of a tourism economy.Some trees have shown growth rates larger than 1 cm diameter per year and most species have had increasing BAI trends over the past decades.Strong growth releases occurred after windstorms at both sites,but the effects of windstorms were site-dependent,with the 1958 storm affecting mainly the eastern tip of the island(Anaga massif)and the 1991 storm the western tip(Teno massif).Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms,passive restoration may be sufficient to regenerate this habitat in currently degraded areas.

Effects of Different Spatial Resolutions on Prediction Accuracy of Thunnus alalunga Fishing Ground in Waters Near the Cook Islands Based on Long Short-Term Memory(LSTM)Neural Network Model

Albacore tuna(Thunnus alalunga)is one of the target species of tuna longline fishing,and waters near the Cook Islands are a vital albacore tuna fishing ground.Marine environmental data are usually presented with different spatial resolutions,which leads to different results in tuna fishery prediction.Study on the impact of different spatial resolutions on the prediction accuracy of albacore tuna fishery to select the best spatial resolution can contribute to better management of albacore tuna resources.The nominal catch per unit effort(CPUE)of albacore tuna is calculated according to vessel monitor system(VMS)data collected from Chinese distantwater fishery enterprises from January 1,2017 to May 31,2021.A total of 26 spatiotemporal and environmental factors,including temperature,salinity,dissolved oxygen of 0–300 m water layer,chlorophyll-a concentration in the sea surface,sea surface height,month,longitude,and latitude,were selected as variables.The temporal resolution of the variables was daily and the spatial resolutions were set to be 0.5°×0.5°,1°×1°,2°×2°,and 5°×5°.The relationship between the nominal CPUE and each individual factor was analyzed to remove the factors irrelavant to the nominal CPUE,together with a multicollinearity diagnosis on the factors to remove factors highly related to the other factors within the four spatial resolutions.The relationship models between CPUE and spatiotemporal and environmental factors by four spatial resolutions were established based on the long short-term memory(LSTM)neural network model.The mean absolute error(MAE)and root mean square error(RMSE)were used to analyze the fitness and accuracy of the models,and to determine the effects of different spatial resolutions on the prediction accuracy of the albacore tuna fishing ground.The results show the resolution of 1°×1°can lead to the best prediction accuracy,with the MAE and RMSE being 0.0268 and 0.0452 respectively,followed by 0.5°×0.5°,2°×2°and 5°×5°with declining prediction accuracy.The results suggested that 1)albacore tuna fishing ground can be predicted by LSTM;2)the VMS records the data in detail and can be used scientifically to calculate the CPUE;3)correlation analysis,and multicollinearity diagnosis are necessary to improve the prediction accuracy of the model;4)the spatial resolution should be 1°×1°in the forecast of albacore tuna fishing ground in waters near the Cook Islands.

Accelerator-mode islands and superdiffusion in double-kicked rotor

This paper presents a theoretical investigation of the presence of acceleration islands in the phase space of doublekicked rotor(DKR) systems, which can lead to superdiffusive behavior. We establish the conditions for the existence of period-1 acceleration centers and subsequently calculate the stability conditions for both period-1 and period-2 accelerate mode islands. A detailed analysis of local and global diffusion in the vicinity of the islands and the stickiness regions is provided. It is demonstrated that the mean stickiness time decays exponentially when the phase point is located in the interior of the island. Moreover, the phase point undergoes a power-law decay with a power equal to approximately 5when entering the sticky region. These findings offer a foundation for future exploration of quantum dynamics in the DKR system.

Study of coexisting upstream solitary wave packet and downstream wakes induced by Diaoyu Dao and its affiliated islands detected by satellite sun glitter

Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.

Seasonal stress on semen quality profiles, seminal biochemical and oxidative stress attributes in endangered Teressa goat of Andaman and Nicobar Islands

Objective:To measure seasonal effects on semen quality profiles,seminal biochemical and oxidative stress attributes in fresh and liquid stored semen in monsoon and dry seasons.Methods:A total of 10 Teressa bucks(3-4 years)were selected from breeding farm,ICAR-Central Island Agricultural Research Institute,Port Blair,Andaman and Nicobar Islands,India.Semen samples(n=25 per season)were collected through artificial vagina method and preserved at refrigerated temperature(5℃)for 48 h using Tris citrate glucose based extender.We detected semen quality parameters[volume,mass activity,pH,sperm concentration,total motility,viability,total sperm abnormality,and plasma membrane,acrosomal and nuclear integrities],biochemical profiles[aspartate amino transferase(AST),alanine amino transferase(ALT)and total cholesterol],and oxidative stress markers[total antioxidant capacity(TAC)and malondialdehyde(MDA)]during monsoon and dry seasons.Results:Semen quality parameters significantly differed between seasons(P<0.05)and among storage periods(P<0.05).Volume,pH,mass activity,motility,viability,acrosomal,plasma membrane and nuclear integrities,and TAC were significantly higher(P<0.05).Sperm concentration,sperm abnormalities,MDA,AST,ALT and total cholesterol were significantly lower in fresh semen of monsoon than dry season(P<0.05).Motility,viability,acrosomal,plasma membrane and nuclear integrities,and TAC were significantly decreased(P<0.05)while sperm abnormality,AST,ALT,total cholesterol and MDA were significantly increased as liquid semen storage period advanced(P<0.05).Conclusions:Monsoon season has higher beneficial effects on semen quality profiles and liquid stored semen remained usable for upto 48 h.Good quality ejaculates with higher TAC and lower MDA can be cryopreserved and will be used for artificial insemination.

An investigation of the morphodynamic change of reef islands under monochromatic waves

The persistence and habitability of coral reef islands in future extreme oceanographic conditions has received increasing attention in the recent decade,concerning that the sea level rise(SLR)and more frequent and intense storms in the context of global climate change are expected to destabilize those islands.Here,we conduct a set of wave-flume laboratory experiments focusing on the morphodynamic change of reef islands to varying ocean forcing conditions(wave height and SLR).Subsequently,a phase-resolving XBeach numerical model is adopted to simulate the monochromatic wave process and its associated sediment dynamics.The adopted model is also firstly validated by laboratory experimental results as reported in this study.It is then used to examine the impacts of island morphological factors(island width,island height,island location and island side slope)on the island migration.The combined laboratory/physical and numerical experiment outputs suggest that reef islands can accrete vertically in response to the sea level rise and the increased storminess.

Community Structure of Fish in Nanji Islands National Nature Reserve and Its Relationship with Environmental Variation

Community structure of fish in relation to environmental variation was investigated in Nanji Islands National Nature Reserve (NINNR). In order to test this relationship, we delineated 25 survey stations with bottom trawling and measured environmental variables. Samples were taken from November 2013 (autumn), February 2014 (winter), May 2014 (spring) and September 2014 (summer). We found a very strong correlation in space and time between temperature and salinity;abundance and biomass in winter;depth and DO in summer then a strong correlation was found respectively between temperature and biomass;salinity and biomass in winter too and finally a moderate correlation between depth and biomass in spring, (P-value < 0.01) with positive correlation (that the other variable or factor has a tendency to increase). We also found out a negative correlation (P-value < 0.05), respectively between salinity and DO;DO and chlorophyll in summer;temperature and salinity;salinity and DO in spring period (mean that the other variable or factor has a tendency to decrease). A negative correlation observed between temperature, salinity and chlorophyll in winter, spring and autumn period were due by a temperature and salinity window open for species blooms through the movement of the TWC and Jiangzhe coastal current close to shore. By comparing diversity of fish species with environmental factors, the community structure of fish varied significantly as physicochemical parameters changed between different stations for each season. As results and according to the species referencing of environmental factors;species diversity, abundance and evenness vary among different stations, corresponding to significant differences of environmental factors (e.g. physicochemical parameters and chlorophyll-a concentration in different sites). Species richness of microfauna was negatively correlated with salinity levels. Furthermore, they were related to the fish community according to the results. This may be due to the fish community’s adaptability in these different variations of environmental factors, but only tolerant members remaining.

Genetic evaluations of island populations of Rhesus Macaque (Macaca mulatta) in China: Implications for conservation management

DEAR EDITOR,The macaques belongs to the genus Macaca,consisting of at least 23 species(Roos et al.,2019).Among all congeners,rhesus macaque(M.mulatta)is regarded as the widest distributed non-human primate species in the world.Its native range spans in East Asia,northern part of Southeast Asia and Indian subcontinent(Liu et al.,2018).Listed as“Least Concern”on the IUCN Red List,this species is locally threatened due to habitat loss and degradation in China and Thailand(Lu et al.,2018).Nevertheless,pet release resulting in hybridization with other congeners(e.g.,rhesus macaque×crab-eating macaque(M.fascicularis))was documented in Hong Kong SAR,China(Wong&Ni,2000),threatening genetic integrity of wild populations.

Gyrokinetic simulation of magnetic-island-induced electric potential vortex mode

Ion temperature gradient(ITG)-driven turbulence with embedded static magnetic islands is simulated by utilizing a gyrokinetic theory-based global turbulence transport code(GKNET)in this work.Different from the traditional equilibrium circular magnetic-surface average(EMSA)method,an advanced algorithm that calculates the perturbed magnetic-surface average(PMSA)of the electric potential has been developed to precisely deal with the zonal flow component in a non-circular magnetic surface perturbed by magnetic islands.Simulations show that the electric potential vortex structure inside islands induced by the magnetic islands is usually of odd parity when using the EMSA method.It is found that the odd symmetry vortex can transfer into an even one after a steep zonal flow gradient,i.e.the flow shear has been built in the vicinity of the magnetic islands by adopting the PMSA algorithm.The phase of the potential vortex in the poloidal cross section is coupled with the zonal flow shear.Such an electric potential vortex mode may be of essential importance in wide topics,such as the turbulence spreading across magnetic islands,neoclassical tearing mode physics,and also the interaction dynamics between the micro-turbulence and MHD activities.

Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.

Effect of Moringa oleifera on semen quality profiles in endangered Teressa goat under tropical humid island ecosystem

Objective:To investigate the effect of Moringa oleifera leaf extract on semen quality parameters in Teressa goat buck.Methods:A total of 25 semen samples from six bucks were selected for the study.Spermatozoa of 150×10^(6) were incubated in 0,300,500 and 700μg of leaf extract as groupⅠ,Ⅱ,Ⅲ and Ⅳ,respectively.Liquid stored semen samples were analysed for motility,viability,total sperm abnormalities,plasma membrane,acrosomal and nuclear integrities,seminal plasma intracellular enzymes[aspartate aminotransferase(AST),alanine aminotransferase(ALT)and lactate dehydrogenase(LDH)]and total antioxidant capacity(TAC)and spermatozoa malondialdehyde(MDA)and cholesterol efflux in comparison with the control group(groupⅠ)for up to 72 h.Results:Moringa oleifera leaf extract(500μg/150×10^(6) spermatozoa)-treated semen had significantly higher motility,viability,plasma membrane,acrosomal and nuclear integrities,and TAC(P<0.05),and had significantly lower total sperm abnormalities,AST,ALT,LDH,MDA production and cholesterol efflux compared to those in other Moringa oleifera leaf extract treated(300 or 700μg/150×10^(6) spermatozoa)and control groups at different hours of liquid storage(P<0.05).Semen quality parameters and TAC showed an increasing trend and total sperm abnormalities,MDA production,leakage of intra-cellular enzymes and cholesterol efflux showed a decreasing trend from group Ⅰto group Ⅲand then an opposite trend from group Ⅲ to group Ⅳ at different hours of liquid storage.Conclusions:Moringa oleifera leaf extract 500μg/150×10^(6) spermatozoa can be used for liquid semen preservation in Teressa goat at Andaman and Nicobar Islands.

Factors Influencing the Spatial Variability of Air Temperature Urban Heat Island Intensity in Chinese Cities

Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.

Coulomb-assisted nonlocal electron transport between two pairs of Majorana bound states in a superconducting island

We investigate the nonlocal transport modulated by Coulomb interactions in devices comprising two interacting Majorana wires,where both nanowires are in proximity to a mesoscopic superconducting(SC)island.Each Majorana bound state(MBS)is coupled to one lead via a quantum dot with resonant levels.In this device,the nonlocal correlations can be induced in the absence of Majorana energy splitting.We find that the negative differential conductance and giant current noise cross correlation could be induced,due to the interplay between nonlocality of MBSs and dynamical Coulomb blockade effect.This feature may provide a signature for the existence of the MBSs.

Local Climate Change Induced by Urbanization on a South China Sea Island

The South China Sea is a hotspot for regional climate research.Over the past 40 years,considerable improvement has been made in the development and utilization of the islands in the South China Sea,leading to a substantial change in the land-use of the islands.However,research on the impact of human development on the local climate of these islands is lacking.This study analyzed the characteristics of local climate changes on the islands in the South China Sea based on data from the Yongxing Island Observation Station and ERA5 re-analysis.Furthermore,the influence of urbanization on the local climate of the South China Sea islands was explored in this study.The findings revealed that the 10-year average temperature in Yongxing Island increased by approximately 1.11℃from 1961 to 2020,and the contribution of island development and urbanization to the local warming rate over 60 years was approximately 36.2%.The linear increasing trend of the annual hot days from 1961–2020 was approximately 14.84 days per decade.The diurnal temperature range exhibited an increasing trend of 0.05℃per decade,whereas the number of cold days decreased by 1.06days per decade.The rapid increase in construction on Yongxing Island from 2005 to 2021 led to a decrease in observed surface wind speed by 0.32 m s^(-1)per decade.Consequently,the number of days with strong winds decreased,whereas the number of days with weak winds increased.Additionally,relative humidity exhibited a rapid decline from 2001 to 2016 and then rebounded.The study also found substantial differences between the ERA5 re-analysis and observation data,particularly in wind speed and relative humidity,indicating that the use of re-analysis data for climate resource assessment and climate change evaluation on island areas may not be feasible.

The variation in basal channels and basal melt rates of Pine Island Ice Shelf

In recent years,there has been a significant acceleration in the thinning,calving and retreat of the Pine Island Ice Shelf(PIIS).The basal channels,results of enhanced basal melting,have the potential to significantly impact the stability of the PIIS.In this study,we used a variety of remote sensing data,including Landsat,REMA DEM,ICESat-1 and ICESat-2 satellite altimetry observations,and Ice Bridge airborne measurements,to study the spatiotemporal changes in the basal channels from 2003 to 2020 and basal melt rate from 2010 to 2017 of the PIIS under the Eulerian framework.We found that the basal channels are highly developed in the PIIS,with a total length exceeding 450 km.Most of the basal channels are ocean-sourced or groundingline-sourced basal channels,caused by the rapid melting under the ice shelf or near the groundingline.A raised seabed prevented warm water intrusion into the eastern branch of the PIIS,resulting in a lower basal melt rate in that area.In contrast,a deepsea trough facilitates warm seawater into the mainstream and the western branch of the PIIS,resulting in a higher basal melt rate in the main-stream,and the surface elevation changes above the basal channels of the mainstream and western branch are more significant.The El Ni?o event in 2015–2016 possibly slowed down the basal melting of the PIIS by modulating wind field,surface sea temperature and depth seawater temperature.Ocean and atmospheric changes were driven by El Ni?o,which can further explain and confirm the changes in the basal melting of the PIIS.

Spatio-temporal Evolution Characteristics and Driving Forces of Winter Urban Heat Island:A Case Study of Rapid Urbanization Area of Fuzhou City,China

Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.