Coral records of Mid-Holocene sea-level highstands and climate responses in the northern South China Sea

High-resolution sea-level data and high-precision dating of corals in the northern South China Sea(SCS)during the Holocene provide a reference and historical background for current and future sea-level changes and a basis for scientific assessment of the evolutionary trend of coral reefs in the SCS.Although sporadic studies have been performed around Hainan Island in the northern SCS,the reconstructed sea level presents different values or is controversial because the indicative meaning of the sea-level indicators were neither quantified nor uniform criteria.Here,we determined the quantitative relationship between modern living coral and sea level by measuring the top surfaces of 27 live Porites corals from the inner reef flat along the east coast of Hainan Island and assessed the accuracy of results obtained using coral as sea-level indicators.Additionally,three in situ fossil Porites corals were analyzed based on elevation measurements,digital X-ray radiography,and U-Th dating.The survey results showed that the indicative meanings for the modern live Porites corals is(146.09±8.35)cm below the mean tide level(MTL).It suggested that their upward growth limit is constrained by the sea level,and the lowest low water is the highest level of survival for the modern live Porites corals.Based on the newly defined indicative meanings,6 new sea-level index points(SLIPs)were obtained and 19 published SLIPs were recalculated.Those SLIPs indicated a relative sea level fluctuation between(227.7±9.8)cm to(154.88±9.8)cm MTL between(5393±25)cal a BP and(3390±12)cal a BP,providing evidences of the Mid-Holocene sea-level highstand in the northern SCS.Besides that,our analysis demonstrated that different sea-level histories may be produced based on different indicative meanings or criteria.The dataset of 276 coral U-Th ages indicates that coral reef development in the northern SCS comprised the initial development,boom growth,decline,and flourishing development again.A comparison with regional records indicated that synergistic effects of climatic and environmental factors were involved in the development of coral reefs in the northern SCS.Thus,the cessation of coral reef development during the Holocene in the northern SCS was probably associated with the dry and cold climate in South China,as reflected in the synchronous weakening of the ENSO and East Asian summer monsoon induced by the reduction of the 65°N summer insolation,which forced the migration of the Intertropical Convergence Zone.

Spatiotemporal dynamics of vegetation response to permafrost degradation in Northeast China

Permafrost in Northeast China is undergoing extensive and rapid degradation,and it is of great importance to understand the dynamics of vegetation response to permafrost degradation during different periods in this region.Based on the meteorological station data and MODIS land surface temperature data,we mapped the distribution of permafrost using the surface frost number(SFN)model to analyze the permafrost degradation processes in Northeast China from 1981 to 2020.We investigated the spatiotemporal variation characteristics of vegetation and its response to permafrost degradation during different periods from 1982 to 2020 using the normalized difference vegetation index(NDVI).We further discussed the dominant factors influencing the vegetation dynamics in the permafrost degradation processes.Results indicated that the permafrost area in Northeast China decreased significantly by 1.01×10^(5) km^(2) in the past 40 a.The permafrost stability continued to weaken,with large areas of stable permafrost(SP)converted to semi-stable permafrost(SSP)and unstable permafrost(UP)after 2000.From 1982 to 2020,NDVI exhibited a significant decreasing trend in the seasonal frost(SF)region,while it exhibited an increasing trend in the permafrost region.NDVI in the UP and SSP regions changed from a significant increasing trend before 2000 to a nonsignificant decreasing trend after 2000.In 78.63%of the permafrost region,there was a negative correlation between the SFN and NDVI from 1982 to 2020.In the SP and SSP regions,the correlation between the SFN and NDVI was predominantly negative,while in the UP region,it was predominantly positive.Temperature was the dominant factor influencing the NDVI variations in the permafrost region from 1982 to 2020,and the impact of precipitation on NDVI variations increased after 2000.The findings elucidate the complex dynamics of vegetation in the permafrost region of Northeast China and provide deeper insights into the response mechanisms of vegetation in cold regions to permafrost degradation induced by climate change.

The Northward Shift of Climatic Belts in China During the Last 50 Years and the Corresponding Seasonal Responses

Along the meridian of 105°E, the Chinese region are divided into two parts, east and west. The results show that in the east part of China the temperate extratropical belt, the warm extratropical belt, and the northern subtropical belt shift northward significantly, whereas the middle subtropical belt and the southern subtropical belt have less or no change. As for the northern subtropical belt, the maximal northward shift can reach 3.7 degrees of latitude. As for the warm extratropical belt, along the meridian of 120°-125°E, the maximal northward shift can reach 3-4 degrees. In the west part of China, each climatic belt changes little. Only in the Xinjiang area are the significant northward shifts. Correspondingly, it is found that in the last 50 years the traditional seasons have changed. For Beijing, Hailar, and Lanzhou, in general, summer becomes longer and winter shorter over the last 50 years. Summer begins early and ends late with respect to early 1950s. Contrary to the summer, winter begins late and ends early with respect to early 1950s. Furthermore, spring and autumn have changed over the last 50 years: with respect to early 1950s spring begins early and autumn begins late.

Temporal and spatial response of vegetation NDVI to temperature and precipitation in eastern China

Temporal and spatial response characteristics of vegetation NDVI to the variation of temperature and precipitation in the whole year, spring, summer and autumn was analyzed from April 1998 to March 2008 based on the SPOT VGT-NDVI data and daily temperature and precipitation data from 205 meteorological stations in eastern China. The results indicate that as a whole, the response of vegetation NDVI to the variation of temperature is more pronounced than that of precipitation in eastern China. Vegetation NDVI maximally responds to the variation of temperature with a lag of about 10 days, and it maximally responds to the variation of precipitation with a lag of about 30 days. The response of vegetation NDVI to temperature and precipitation is most pronounced in autumn, and has the longest lag in summer. Spatially, the maximum response of vegetation NDVI to the variation of temperature is more pronounced in the northern and middle parts than in the southern part of eastern China. The maximum response of vegetation NDVI to the variation of precipitation is more pronounced in the northern part than in the middle and southern parts of eastern China. The response of vegetation NDVI to the variation of temperature has longer lag in the northern and southern parts than in the middle part of eastern China. The response of vegetation NDVl to the variation of precipitation has the longest lag in the southern part, and the shortest lag in the northern part of eastern China. The response of vegetation NDVI to the variation of temperature and precipitation in eastern China is mainly consistent with other results, but the lag time of vegetation NDVI to the variation of temperature and precipitation has some differences with those results of the monsoon region of eastern China.

Response of soil fauna to simulated nitrogen deposition: A nursery experiment in subtropical China

We studied the responses of soil fauna to a simulated nitrogen deposition in nursery experimental plots in Subtropical China. Dissolved NH4NO3 was applied to the soil by spraying twice per month for 16 months, starting January 2003 with treatments of 0, 5, 10, 15 and 30 gN/（m^2·a）. Soil fauna was sampled after 6, 9, 13 and 16 months of treatment in three soil depths （0-5 cm, 5-10 cm, 10-15 cm）. Soil available N increased in correspondence with the increasing N treatment, whereas soil pH decreased. Bacterial and fungal densities were elevated by the N treatment. Soil fauna increased in the lower nitrogen treatments but decreased in the higher N treatments, which might indicate that there was a threshold around 10 gN/（m^2·a） for the stimulating effects of N addition. The N effects were dependent on the soil depth and sampling time. The data also suggested that the effects of the different N treatments were related to the level of N saturation, especially the concentration of NO3^- in the soil.

Geographic Variation of Rice Yield Response to Past Climate Change in China

Previous studies demonstrated climate change had reduced rice yield in China, but the magnitude of the reduction and the spatial variations of the impact have remained in controversy to date. Based on a gridded daily weather dataset, we found there were obvious changes in temperatures, diurnal temperature range, and radiation during the rice-growing season from 1961 to 2010 in China. These changes resulted in a signiifcant decline of simulated national rice yield （simulated with CERES-Rice）, with a magnitude of 11.5%. However, changes in growing-season radiation and diurnal temperature range, not growing-season temperatures, contributed most to the simulated yield reduction, which conifrmed previous estimates by empirical studies. Yield responses to changes of the climatic variables varied across different rice production areas. In rice production areas with the mean growing-season temperature at 12-14＆#176;C and above 20＆#176;C, a 1＆#176;C growing-season warming decreased rice yield by roughly 4%. This decrease was partly attributed to increased heat stresses and shorter growth period under the warmer climate. In some rice areas of the southern China and the Yangtze River Basin where the rice growing-season temperature was greater than 20＆#176;C, decrease in the growing-season radiation partly interpreted the widespread yield decline of the simulation, suggesting the signiifcant negative contribution of recent global dimming on rice production in China＇s main rice areas. Whereas in the northern rice production areas with relatively low growing-season temperature, decrease of the diurnal temperature range was identiifed as the main climatic contributor for the decline of simulated rice yield, with larger decreasing magnitude under cooler areas.

Characteristics of Extreme Temperature Event and Its Response to Regional Warming in Northwest China in Past 45 Years

Using the daily maximum and minimum temperature dataset from 128 stations from 1960 to 2004 in Northwest China,daily extreme high temperature(EHT)and extreme low temperature(ELT)thresholds were deter-mined by centesimal method for different stations at first,then yearly EHT and ELT events were counted up in differ-ent stations,and the characteristics of their spatio-temporal distribution were diagnosed at last.The study drew follow-ing conclusions:1)The consistent anomaly distribution characteristic was the most important mode of the EHT and ELT events in Northwest China.2)The spatial distribution of the EHT and ELT events can be divided into five sub-regions,namely,the north of Qinghai and west of Gansu,the north of Xinjiang,the south of Xinjiang,the east of Northwest China and the south of Qinghai.3)The EHT events showed remarkable increasing trend in all of five sub-regions,but only in the north of Qinghai and west of Gansu area,sudden change phenomenon occurred;the ELT events showed decreasing trend in all of five sub-regions,and sudden change phenomenon occurred in Northwest China except for south of Qinghai.4)In all of five sub-regions the EHT events showed remarkable 12-14yr period os-cillation,and the ELT event showed significant 13-15yr and 7-8yr period oscillation.5)The EHT and ELT events displayed remarkable positive and negative responses to regional warming of Northwest China respectively.

A geomorphological response of beaches to Typhoon Meari in the eastern Shandong Peninsula in China

Eight representative beach profiles on the eastern coast of the Shandong Peninsula are observed and measured in 2011 and 2012 to determine the coastal processes under the lower tropical wind speed condition and the beach response to and recovery from the tropical storm Meari in a rare typhoon region. The results show that it is the enhancement and directional change of cross-shore and longshore sediment transports caused by Meari that leads to the beach morphological changes, and most of the sediment transports occur during the pre-Meari landing phase. The erosional scarp formation and the berm or beach face erosion are the main geomorphological responses of the beaches to the storm. The storm characteristics are more important than the beach shapes in the storm response process of the beaches on Shandong Peninsula. The typhoon is a fortuitous strong dynamic event, and the effect on the dissipative beach is more obvious than it is on the reflective beach in the study region. Furthermore, the beach trend is the main factor that controlls the storm effect intensity, and it is also closely related to the recovery of the beach profiles.

Estimating peak response frequencies in a tidal band in the seas adjacent to China with a numerical model

A numerical method is designed to examine the response properties of real sea areas to open ocean forcing. The application of this method to modeling the China＇s adjacent seas shows that the Bohai Sea has a highest peak response frequency （PRF） of 1.52 d^-1; the northern Yellow Sea has a PRF of 1.69 d^-1; the Gyeonggi Bay has a high amplitude gain plateau in the frequency band roughly from 1.7 to 2.7 d^-1; the Yellow Sea （includ- ing the Gyeonggi Bay）, the East China Sea shelf and the Taiwan Strait have a common high amplitude gain band with frequencies around 1.76 to 1.78 d^-1 and are shown to be a system that responds to the open ocean forcing in favor of amplifying the waves with frequencies in this band; the Beibu Gulf, the Gulf of Thailand and the South China Sea deep basin have PRFs of 0.91, 1.01 and 0.98 d^-1 respectively. In addition, the East China Sea has a Poincare mode PRF of 3.91 d^-1. The PRFs of the Bohal Sea, the northern Yellow Sea, the Bei- bu Gulf and the South China Sea can be explained by a classical quarter （half for the Bohai Sea） wavelength resonance theory. The results show that further investigations are needed for the response dynamics of the Yellow Sea-East China Sea-Taiwan Strait system, the East China Sea Poincare mode, the Talwan Strait, and the Gulf of Thailand.

Atmospheric Response to Mesoscale Ocean Eddies over the South China Sea

The South China Sea（SCS） is an eddy-active area. Composite analyses based on 438 mesoscale ocean eddies during 2000–2012 revealed the status of the atmospheric boundary layer is influenced remarkably by such eddies. The results showed cold-core cyclonic（warm-core anticyclonic） eddies tend to cool（warm） the overlying atmosphere and cause surface winds to decelerate（accelerate）. More than 5% of the total variance of turbulent heat fluxes, surface wind speed and evaporation rate are induced by mesoscale eddies. Furthermore, mesoscale eddies locally affect the columnar water vapor, cloud liquid water, and rain rate. Dynamical analyses indicated that both variations of atmospheric boundary layer stability and sea level pressure are responsible for atmospheric anomalies over mesoscale eddies. To reveal further details about the mechanisms of atmospheric responses to mesoscale eddies, atmospheric manifestations over a pair of cold and warm eddies in the southwestern SCS were simulated. Eddy-induced heat flux anomalies lead to changes in atmospheric stability. Thus, anomalous turbulence kinetic energy and friction velocity arise over the eddy dipole, which reduce（enhance） the vertical momentum transport over the cold（warm） eddy, resulting in the decrease（increase） of sea surface wind. Diagnoses of the model＇s momentum balance suggested that wind speed anomalies directly over the eddy dipole are dominated by vertical mixing terms within the atmospheric boundary layer, while wind anomalies on the edges of eddies are produced by atmospheric pressure gradient forces and atmospheric horizontal advection terms.

Factors Influencing the Emergency Medical Service Response Time for Cardiovascular Disease in Guangzhou, China

While emergency medical service (EMS) response time (ERT) is a major factor associated with the survival of patients with cardiovascular disease (CVD), relatively few studies have explored the factors associated with ERT. This study aimed to assess the current status of ERT and to identify the factors affecting ERT in patients with CVD in China. Between January 1, 2011 and December 31, 2015, EMS responses to CVD incidents in Guangzhou, China, were examined. The primary outcome was ERT, defined as the time from receipt of an emergency call to the arrival of paramedics on the scene. Factors associated with ERT were evaluated by multivariable logistic regression. A total of 44 383 CVD incidents were analysed. The median ERT was 12.58 min (interquartile range=9.98-15.67). Among the risk factors, distance (OR=13.73, 95% CI=11.76- 16.04), level of hospital (OR=1.57, 95% CI=1.40-1.75), and site of the incident (OR=1.53, 95% CI=1.38-1.69) were the top three significant factors affecting the ERT. Our results suggest that greater attention should be given to factors affecting the ERT. It is essential to make continuous efforts to promote the development of effective interventions to reduce the response time.

Drought Response to Air Temperature Change over China on the Centennial Scale

Climate data from the Climatic Research Unit （CRU） for the period 1901-2013 are used to investigate the drought response to air temperature change over China on the centennial scale. Drought is observed to have increased evidently across China, except for some regions in eastern China. This increase is much stronger in northern China compared to southern China, especially in Northwest and North China. These change characteris- tics of drought are closely associated with air temperature change, with the severe droughts in the major drought episodes of the last century generally coinciding with higher temperatures. The significantly increasing trend of drought in China based on observations only appears when considering the effects of air temperature change, which can explain -49% of droughts in observations and 30%-65% of droughts in Coupled Model Intereomparison Project Phase 5 （CMIP5） model simulations. Furthermore, the response of drought to air temperature change generally increases as the drought time scale increases. Furthermore, drought shows relatively high sensitivity in spring and early summer in China on the centennial scale.

Asymmetric Response of the South China Sea SST to El Nio and La Nia

The interannual variability of the sea surface temperature （SST） in the South China Sea （SCS） is investigated according to its relationship with E1 Nifio/La Nifia （EN/LN） using monthly products from ICOADS. The SCS SST bears two peaks associated with EN/LN and shows the asymmetric features. Coinciding with the mature phase of EN/LN, the first SST warming/cooling peaks in December（0）-February（1） （DJF（1）） and centers in the southern part. The major difference is in the amplitude associated with the strength of EN/LN. However, the SCS SST anomaly shows distinct difference after the mature phase of EN/LN. The EN SST warm- ing develops a mid-summer peak in June-August（1） （JJA（1）） and persists up to September-October（l）, with the same amplitude of the first warming peak. Whereas the LN SST cooling peaks in May（l）, it decays slowly until the end of the year, with amplitude much weaker. Comparing with SST and atmospheric circulations, the weak response and early termination of the second cooling is due to the failure of the cyclonic wind anomalies to develop in the northwest Pacific during JJA（1）.

‘Outbreak Gold Standard’Selection to Provide Optimized Threshold for Infectious Diseases Early-alert Based on China Infectious Disease Automated-alert and Response System

The China Infectious Disease Automated-alert and Response System（CIDARS） was successfully implemented and became operational nationwide in 2008. The CIDARS plays an important role in and has been integrated into the routine outbreak monitoring efforts of the Center for Disease Control（CDC） at all levels in China. In the CIDARS, thresholds are determined using the ？Mean＋2SD？ in the early stage which have limitations. This study compared the performance of optimized thresholds defined using the ？Mean ＋2SD？ method to the performance of 5 novel algorithms to select optimal ？Outbreak Gold Standard（OGS）？ and corresponding thresholds for outbreak detection. Data for infectious disease were organized by calendar week and year. The ？Mean＋2 SD？, C1, C2, moving average（MA）, seasonal model（SM）, and cumulative sum（CUSUM） algorithms were applied. Outbreak signals for the predicted value（Px） were calculated using a percentile-based moving window. When the outbreak signals generated by an algorithm were in line with a Px generated outbreak signal for each week, this Px was then defined as the optimized threshold for that algorithm. In this study, six infectious diseases were selected and classified into TYPE A（chickenpox and mumps）, TYPE B（influenza and rubella） and TYPE C [hand foot and mouth disease（HFMD） and scarlet fever]. Optimized thresholds for chickenpox（P_（55））, mumps（P_（50））, influenza（P_（40）, P_（55）, and P_（75））, rubella（P_（45） and P_（75））, HFMD（P_（65） and P_（70））, and scarlet fever（P_（75） and P_（80）） were identified. The C1, C2, CUSUM, SM, and MA algorithms were appropriate for TYPE A. All 6 algorithms were appropriate for TYPE B. C1 and CUSUM algorithms were appropriate for TYPE C. It is critical to incorporate more flexible algorithms as OGS into the CIDRAS and to identify the proper OGS and corresponding recommended optimized threshold by different infectious disease types.

Impact of Climatic Change on Agricultural Production and Response Strategies in China

A number of studies indicate that global climate warming has been increasing, especially in recent decades. Climate warming greatly affects global agro-production and food security-- becoming a hotspot of global environmental change. This paper proposes a structural and orientational framework for scientifically addressing climatic change impact on agroroduction. Through literature reviews and comparative studies, the paper systematically summarizes influencing mechanisms and impact of climate warming on such agro-production factors as light, temperature, soil quality and water environment. The impact of climate warm- ing on cultivation regions, cropping systems, crop pests, agro- production capacity, agro-economy and farm management is analyzed. Then, suitable climate-adapting agro-development strategies are put forward for different regions in China. The strategies are carefully selected from a repository of international tested climatic change countermeasures in agriculture at national or district level.

RESPONSE OF TRIASSIC SEQUENCE STRATIGRAPHY OF LOWER YANGTZE TO THE COLLISION BETWEEN THE YANGTZE PLATE AND THE NORTH CHINA PLATE

The characteristics of the Triassic sequences developed in the Lower Yangtze area display some great changes in both environment and climate. The change of environment was a transition from marine to continent via alternating environments. The change of climate was a transition from tropic （torrid） to warm and wet climate via subtropic dry climate. The type variations of the sequences were from the marine sequences to the continental sequences, corresponding to the changes of environments and climates. Sequence 1 is a type II of sequence of mixed elastic and carbonate sediments; sequence 2 is a type I of sequence of carbonate platform; sequence 3 is a type I of sequence of carbonate tidal flat-salt lagoon, sequence 4 is a type iI of sequence of lacustrine within marine layers, and sequence 5 is a sequence of lacustrine-swamp. The development, distribution and preservation of those sequences reveal the tectonic controls and their changes in the background. The collision between the Yangtze plate and the North China plate was a great geological event in the geological history, but the timing of the collision is still disputed. However, the characteristics of Triassic sequence stratigraphy and sea level changes in the Lower Yangtze area responded to this collision. The collision started at the beginning of middle Triassic and the great regression in the Lower Yangtze area started 22Ma earlier than those in the world. The tectonic conditions occurred before and during the collision controlled the development of sequences and type changes.

China＇s Military Build-up and India＇s Response

Since the 1990s, the rise of China has become realized. China has shown dramatic economic, and expanded its political influences at both regional and international levels. More importantly, it has accelerated its military build-up since the 1990s, and widened a gap between military capabilities of China and those of neighboring countries. In response to China＇s strengthening military power and capability, India, one of the most potential competitors for regional hegemony, is at a crossroads. How has India perceived China＇s remarkable military build-up？ And, based on India＇s perception, how has it responded？ This article argues that, relying on the logic of neorealism, India has seen China＇s military build-up as a significant threat to its national interest and security. After exploring India＇s strategies in response to China＇s strengthening military power, empirical analysis reveals that, facing a threat from China＇s growing military power, India＇s response could be characterized as internal and external balancing against China.

Research on Cultural Differences of China and the United States From the Perspective of Difference of Compliment Responses

In all the culture of the world, compliment is always one kind of communicative applications, which is quite frequently used, we see compliment both in China and the United States. By reason of the culture difference of different countries, Chinese and American often have diverse responses and attitudes toward the compliment, which directly cause their different responses when they make reactions to the compliment.[1]From study, we see the difference is mainly in the following, on one hand, the Chinese are often very implicative toward the compliment and they respect all other people while they are quite humble when in the communication, on the other hand, the American are much more public, although they also respect other people, they are not keeping humble at the same time.

Erosion response to anthropogenic activity and climatic changes during the Holocene: case studies in northwestern China and southern Norway

Soil erosion assessment and prediction play critical roles in addressing problems associated with erosion control or soil conservation. The past dynamics of soil erosion can provide valuable information for us to understand the relations of soil erosion to environmental change and anthropogenic activity. The present paper has compared Holocene climatic changes in northwestern China with those in southern Norway, and investigated the past dynamics of erosion activity during the Holocene. Modern soil erosion on the Loess Plateau is a combination of the intensive natural erosion and human-induced erosion, the latter being four times greater than the former. Because of global warming and increasing human activities, climate on the Loess Plateau is becoming dryer and more unstable, causing an enhanced erosion problem and water scarcity. In the arctic-alpine region of southern Norway, however, the global warming and regional wetting caused expansion of the largest European ice cap. This has accentuated the erosion in that region, with a higher frequency of avalanches and debris flows.

CHINA'S VEGETATION/ECOSYSTEM RESPONSE TO GLOBAL CHANGE: RESEARCH PROGRESS & PROSPECTS

This paper presents the latest developments in the re search progress on mechanisms by which natural plants and crops respond to the doubled concentration of CO2 in the atmosphere, resultant climatic change and the modeling of vegetation and eco-systems in China. In addition, it points out that the future study on global change and terrestrial ecosystems should stress m(?)iti-disciplinary teamwork and inter-discipline penetration. Finally, the paper emphasizes 10 research realms in the field to be enhanced in the future.