渤海湾西岸CZ01钻孔沉积物粒度端元分析及其气候—海平面变化响应

沧州地区位于海陆交互的渤海湾西岸,易受到海平面变化和极端气候事件的影响,对于全球气候变化的响应十分敏感。应用非参数化端元分析模型将沧州地区CZ01钻孔中更新世晚期以来的沉积物粒度划分出6个端元并分析其物源,结合已有地质记录,揭示不同时间尺度下各端元对气候—海平面变化的响应。结果表明:(1)EM1(5.01μm)主要为远源的风尘输入,EM2(13.18μm)和EM3(39.81μm)为古黄河所携带的沉积物,EM4(69.18μm)和EM5(138.04μm)为海相沉积物,EM6(275.42μm)可能指示古洪水等极端气候事件。(2)深海氧同位素(MIS)Ⅰ阶段,气候温暖湿润,EM4+5含量指示渤海海平面整体呈波动上升的趋势并逐渐接近现代海平面。该阶段内由于11.5 ka BP左右的新仙女木事件以及5.1 ka BP左右冷干事件的发生,渤海海平面在稳定上升状态后出现停滞或小幅下降的现象;而在9.5 ka BP、7.5 ka BP、5.8 ka BP和1.7 ka BP左右,东亚夏季风增强导致降水增加,渤海海平面升高。(3)MISⅥ阶段北半球气候冷干,150~132 ka BP左右因喜马拉雅运动减弱造成的区域沉降中心转移致使渤海海面升高。MISⅤ阶段气候波动剧烈:在间冰期暖期(5a、5c和5e)气候暖湿,渤海海平面上升;而MIS5b和5d时期渤海海面高度较低。MISⅣ阶段较MIS5a末期海平面突然下降后趋于稳定,期间出现若干次小规模海侵事件,可能与东亚夏季风频繁变化有关。MISⅢ阶段至末次冰盛期海平面大幅度下降且存在周期性升降变化,并在46 ka BP左右出现大规模海侵事件。MISⅡ阶段较MISⅢ阶段海平面出现小幅度下降,为低海平面时期;伴随15 ka BP左右冰盛期的结束,东亚夏季风增强,海平面开始上升。渤海海平面180 ka BP以来的变化记录与北半球乃至全球范围内的地质记录存在一致性,与太阳辐射波动引起的冰川消融及东亚夏季风变化密切相关。

Assessing the Impacts of Eurasian Snow Conditions on Climate Predictability with a Global Climate Model

On the basis of two ensemble experiments conducted by a general atmospheric circulation model(Institute of Atmospheric Physics nine-level atmospheric general circulation model coupled with land surface model,hereinafter referred to as IAP9L_CoLM),the impacts of realistic Eurasian snow conditions on summer climate predictability were investigated.The predictive skill of sea level pressures(SLP)and middle and upper tropospheric geopotential heights at mid-high latitudes of Eurasia was enhanced when improved Eurasian snow conditions were introduced into the model.Furthermore,the model skill in reproducing the interannual variation and spatial distribution of the surface air temperature(SAT)anomalies over China was improved by applying realistic(prescribed)Eurasian snow conditions.The predictive skill of the summer precipitation in China was low;however,when realistic snow conditions were employed,the predictability increased,illustrating the effectiveness of the application of realistic Eurasian snow conditions.Overall,the results of the present study suggested that Eurasian snow conditions have a significant effect on dynamical seasonal prediction in China.When Eurasian snow conditions in the global climate model(GCM)can be more realistically represented,the predictability of summer climate over China increases.

Primary Discussion of a Carbon Sink in the Oceans

As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people＇s living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula： C=A-B and G=E＋F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the calrying capacity of the oceans.

The Oscillation between Tropical Indian Ocean and North Pacific:Evidence and Possible Impact on Winter Climate in China

This paper provides evidence that the variation of boreal winter sea level pressure (SLP) over the North Pacific is out-of-phase with SLP fluctuation over the tropical Indian Ocean on both the interdecadal and interannual time scales.Subsequently,a SLP between tropical Indian Ocean and North Pacific (TIO-NP) oscillation index is defined to indicate the variation of such out-of-phase fluctuation.Moreover,the simultaneous surface air temperature and precipitation anomalies in China are closely related to TIO-NP oscillations.Below-normal surface air temperature anomalies in the northern and the eastern part of China,and less rainfall in southern China,correspond to positive TIO-NP oscillation phase with negative SLP anomalies in tropical Indian Ocean and positive anomalies in North Pacific.The TIO-NP oscillation affects China's winter climate anomalies,possibly through modulating the northeast East Asia winter monsoon.

Changes in key indicators of coastal marine climate in China

Based on the observation data from China coastal marine stations,the key indicators of marine climate along China coast were explored,including sea surface t emperature(SST),sea level and sea ice.Results show that:(a)The SST along China coast continues rising and increased by 0.25℃/decade during 1980-2019,the warming accelerated significantly after 2011 and it has been well above normal for five consecutive years since 2015.In 2019,the average SST along China coast was 1.1℃ higher than normal(with 1981-2010 taken as a reference period),ranking the highest since 1980.Besides,the SST extremes have been explored based on four long-term marine stations for the period 1960-2019.(b)Sea level along China coast continues to rise at an accelerated rate.The mean sea level rise rate along China Coast was about 2.4 mm/yr during 1960-2019,3.4 mm/yr during 1980-2019,and 3.9 mm/yr during 1993-2019,with significant regional differences.The relatively stronger sea level rise trends were observed along the coastal waters of the Bohai Bay,the Laizhou Bay,the Yangtze River Estuary,the Pearl River Estuary,and the Hainan Island,respectively.Besides,the extreme sea levels along China coast showed an obvious upward trend from 1980 to 2019.During this period,the annual rise rate of extreme high water level along China coast was 4.4 mm/yr,and had obvious regional characteristics,with the highest rate of 9.9 mm/yr observed at Yantai of Shandong Province,(c)The annual sea ice period and sea ice cover of the Bohai Sea(BS)decreased substantially during 1963-2019 by 0.7-1.3 days/yr and 45-59%/yr,respectively,and the decrease rate of ice cover is larger in the north than that in the south.2019 was the year of light icing.

Numerieal Prediction of Storm Surge in the Qingdao Area Under the Impact of Climate Change

A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for simulating the associated storm surge with a 200 m resolution along the Qingdao coastline. The system was validated by an extreme surge event Typhoon Mamie(8509) and the parameters of Typhoon Mamie were used to investigate the sensitivity of typhoon paths to Qingdao storm surges with four selected paths: the paths of Typhoons Mamie(8509), Opal, 3921 and 2413, the selection being made according to their relative position to Qingdao. Experiments based on the Typhoon Mamie(8509) storm surge were also conducted to study the possible influences of future climate changes, including the sea level rise and sea surface temperature(SST) rise, on storm surges along the Qingdao coast. Storm surge conditions under both present day and future(the end of the 21 st century) climate scenarios associated with the four selected paths were simulated. The results show that with the same intensity, when typhoons follow the paths of 3921 and 2413, they would lead to the most serious disasters in different areas of Qingdao. Sea level and SST affect storm surges in different ways: sea level rise affects storm surge mainly through its influence on the tide amplitude, while the increased SST has direct impact on the intensity of the surges. The possible maximum risk of storm surges in 2100 in the Qingdao area caused by typhoons like Mamie(8509) was also estimated in this study.

A Method for Improving Simulation of PNA Teleconnection Interannual Variation in a Climate Model

The climate modeling community has been challenged to develop a method for improving the simulation of the Pacific-North America （PNA） teleconnection pattern in climate models. The accuracy of PNA teleconnection simulation is significantly improved by considering mesoscale convection contributions to sea surface fluxes. The variation in the PNA over the past 22 years was simulated by the Grid Atmospheric Model of lAP LASG version 1.0 （GAMIL1.0）, which was guided by observational SST from January 1979 to December 2000. Results show that heating in the tropical central-eastern Pacific is simulated more realistically, and sea surface latent heat flux and precipitation anomalies are more similar to the reanalysis data when mesoscale enhancement is considered during the parameterization scheme of sea surface turbulent fluxes in GAMIL1.0. Realistic heating in the tropical central-eastern Pacific in turn significantly improves the simulation of interannual variation and spatial patterns of PNA.

Assessment of Salinity Intrusion in the Red River under the Effect of Climate Change

This paper focuses on analysis of salinity distribution along Red River and its main branches to determine and limit effects of salinity intrusion under variable scenarios for outlet discharge from upstream reservoirs and the tidal magnitude under global climate change effects. The effect of outlet discharge from upstream reservoirs, which generates flow in droughty months, is considered as upstream input condition for salinity intrusion. The sea level rising phenomenon is represented by scenarios according to prediction of the Intergovernmental Panel on Climate Change （IPCC）. The lateral flow and the rainfall in dry season are neglected in the process of simulation. MIKE 11, ID river model software by DHI （Danish Hydraulic Institute）, is used to simulate the processes of salt water intrusion from the river mouths to the upstream of the river in consideration the effect of the Sea Level Rise phenomenon and the operation of existing reservoirs and those under construction. The results indicate that salinity intrusion length from river mouth depends on the estuary characteristics, discharges from upper reservoirs and tidal phases （low and high tides）. With the safe salinity concentration for agriculture and livestock is 4 psu, the study shows that the length of intruded salt in Red River is about 40km from the river mouth, in otherwise, the effect of salinity intrusion in Thai Binh river is negligible. The Sea Level Rise phenomenon has inconsiderable affects on salinity intrusion processes in Red River System. The influence of outlet discharges from upstream reservoirs has also negligible affects on prevent salinity intrusion from the sea. According to the results of the study, reasonable water resources utilization and appropriate reservoir operation approaches in the drought will be studied to protect the crop and aquaculture from salinity intrusion.

Study on Establishing a Monitoring System for Groundwater in the Condition of Climate Change and Sea Level Rise： Case Study of Ma River Basin in Vietnam

The results presented in this paper are a part of the research results of the thesis ＂research on scientific basis and practice of develop a system of monitoring the impacts of climate change on surface water and groundwater＂. Case study： Ma river basin in Vietnam. The results were implemented： （i） data collection, fieldwork survey, synthesis and analysis of information and data; （ii） partitioning the influence degree of climate change and sea level rise to groundwater; （iii） determining criteria to select monitoring routes, location of monitoring groundwater in the condition of climate change and sea level rise and （iv） developing the monitoring system. The research＇s results have practical implications for the water resources management in the context of climate change and sea level rise in Ma river basin.

The Effects of Climate Change and Sea Level Rise on Dry Season Flows in Tien River and Hau River

Tien river and Hau river are two main branches of Cuu Long River which have hydrology regime directly effected by climate change and sea level rise. The flow of the dry season in the Tien and Hau rivers plays a key role in the socio-economic development of the Mekong Delta, especially in agricultural production. The study aims to provide useful information in socio-economic development planning and water use strategies for managers, planners and policymarkers of the provinces/cities in the Mekong Delta. This paper presents the study results in changing of dry season flows in Tien river and Hau river under the impacts of climate change in order to propose measures for protection, substainable development and water security.

The paleoclimate environment and recent sea level change on the seashores of Thailand Gulf in Southeast Asia

This paper analyzed and researched on several significant natural geological sections from the views of stratum-sequence stratigraphy,climate stratigraphy,event stratigraphy and regional stratigraphy by the investigation of Thailand,Malaysia and Singapore. In combination with the coupling relationship between the life-temperature of regional life zone and the evolution of geological environment,this paper exactly made out the geological sediment records of paleoclimate times in different time scales of 3 kaBP,1 kaBP and 0.5 kaBP since the past glacier age of Quaternary period,and it is consecutive and authentic for the material medium and time joint. These studies definitely reflected that the sea level of Thailand Gulf area is in tendency of continually dropping in recent years. They also provided important and new information for the global change analysis.

Evidence of Climate Variability in Imo State of Southeastern Nigeria

Climate variation generally occurs at local scale, regional scale, national scale and global scale. Having established that the global climate has varied slowly over the past millennia, centuries, and decades and it is expected to continue to vary in future. Like the climate change, variability may be due to, national internal processes within the climate （internal variability）, or variations in natural or anthropogenic external forces （external variability）. Evidence of climate variations is now well documented, and the implications are becoming increasingly clear as data accumulates and data and climate models become increasingly sophisticated. The fluctuations in rainfall and temperature regimes are the atmospheric driving forces that are responsible for the climate variations over the southeastern Nigeria including Imo State as the case in other parts of the world. It is on this premise that this study examined the evidence of climate variability in Imo State of the southeastern Nigeria. The study employed the holistic use of real meteorological data from Nigerian Meteorological Department on two weather parameters （temperature and rainfall）, for 30 years （1980-2009）. Results indicated fluctuations in temperature and rainfall regimes within the period under study, which were the reasons for the variations in climate of the region. Apparently, evidence of climate variability are indicated by increasing surface air temperature, increasing heat waves which enhances disease vectors, communicable diseases and epidemics, sea level rise and associated coastal erosion, flooding, increased evaporation that dry up streams and rivers etc..

Evaluation of farmland losses from sea level rise and storm surges in the Pearl River Delta region under global climate change

The Pearl River Delta on China's coast is a region that is seriously threatened by sea level rise and storm surges induced by global climate change, which causes flooding of large areas of farmland and huge agricultural losses. Based on relevant research and experience, a loss evaluation model of farmland yield caused by sea level rise and storm surges was established. In this model, the area of submerged farmland, area of crops, and per unit yield of every type of crop were considered, but the impact of wind, flooding time, changes in land use and plant structure were not considered for long-term prediction. Taking the Pearl River Delta region in Guangdong as the study area, we estimated and analyzed the spatial distribution and loss of farmlands for different scenarios in the years 2030, 2050, and 2100, using a digital elevation model, land-use data, local crop structure, rotation patterns, and yield loss ratios for different submerged heights obtained from field survey and questionnaires. The results show that the proportion of submerged farmlands and losses of agricultural production in the Pearl River Delta region will increase gradually from 2030 to 2100. Yangjiang, Foshan, and Dongguan show obvious increases in submerged farmlands, while Guangzhou and Zhuhai show slow increases. In agricultural losses, vegetables would sustain the largest loss of production, followed by rice and peanuts. The greatest loss of rice crops would occur in Jiangmen, and the loss of vegetable crops would be high in Shanwei and Jiangmen. Although losses of peanut crops are generally lower, Jiangmen, Guangzhou, and Shanwei would experience relatively high losses. Finally, some measures to defend against storm surges are suggested, such as building sea walls and gates in Jiangmen, Huizhou, and Shanwei, enforcing ecological protection to reduce destruction from storm surges, and strengthening disaster warning systems.