Sea level change and forecast in the future — climate of the past,today and the future

The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is ＋1.32 ＋ 0.22 mm/a, while the sea level change rate in China is only＋1.39 ＋ 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages （periods） are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise ＋7 - ＋11 ＋ 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently.

Atmospheric nitrogen deposition in Yangtze River Delta:insights gained from the nitrogen content and isotopic composition of the moss Haplocladium microphyllum

Simple and inexpensive estimation of the rates and sources of atmospheric nitrogen(N)deposition is critical for its effective mitigation in a region with different land-use types.In this study,the N content and N isotopic composition(δ15N)of moss(Haplocladium microphyllum)tissues and precipitation at six sites with three land-use types(urban,suburban,and rural)were measured in the Yangtze River Delta.A significant linear relationship between moss N content and wet N deposition,and a consistent decrease trend for moss N content and wet N deposition from urban to suburban to rural areas were observed.More negativeδ15N of suburban and rural mosses indicated N mainly released from agriculture and effluent,while the less negativeδ15N of urban mosses were mainly influenced by fossil fuel combustion and traffic emissions.Although the negative mossδ15N indicates that reduced N dominates wet N deposition,there was no significant correlation between mossδ15N and the ratio of ammonium to nitrate(NH4+/NO3−).These results reveal that the moss N content andδ15N can be used as a complementary tool for estimating the rates and sources of wet N deposition in a region with different land-use types.

Inter-decadal variations,causes and future projection of the Asian summer monsoon

The present paper presents a concise summary of our recent studies on the Asian summer monsoon,with highting decadal and inter- decadal scales. The studies on the long- term variations of the Asian summer monsoon and its impacts on the change in the summer precipitation in China are reviewed. Moreover,recent changes in the Asian summer monsoon and summer precipitation in East Asia(including Meiyu precipitation)are discussed. Finally,the future changes of the Asian summer monsoon are also pointed out in this paper.

Isotopic composition of precipitation over Arid Northwestern China and its implications for the water vapor origin

In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.

Stable Isotopes in Precipitation in Xilin River Basin,Northern China and Their Implications

Under the increasing pressure of water shortage and steppe degradation, information on the hydrological cycle in steppe region in Inner Mongolia, China is urgently needed. An intensive investigation of the temporal varia-tions of δD and δ^18O in precipitation was conducted in 2007-2008 in the Xilin River Basin, Inner Mongolia in the northern China. The 6D and δ^18O values for 54 precipitation samples range from ＋1.1%o to -34.7%0 and -3.0%0 to -269%0, respectively. This wide range indicates that stable isotopes in precipitation are primarily controlled by differ-ent condensation mechanisms as a function of air temperature and varying sources of vapor. The relationship between δD and δ^18O defined a well constrained line given by δD = 7.896180 ＋ 9.5, which is nearly identical to the Meteoric Water Line in the northern China. The temperature effect is clearly displayed in this area. The results of backward tra-jectory of each precipitation day show that the vapor of the precipitation in cold season （October to March） mainly originates from the west while the moisture source is more complicated in warm season （April to September）. A light precipitation amount effect existes at the precipitation event scale in this area. The vapor source of precipitation with higher d-excesses are mainly from the west wind or neighboring inland area and precipitation with lower d-excesses from a monsoon source from the southeastern China.

Decreasing of Grid-Tied PV Power Output due to Thick Haze Phenomena in Malaysia

Recently, thick haze and poisonous smoke have cloaked the surrounding air in Malaysia due to the uncontrollable and unethical burning of nearby country. This devastating episode of open burning started in the year 1997 in Indonesia which deeply affected most of the ASEAN （association of southeast asian nations） countries especially their neighbour Malaysia and Singapore. The PV （photovoltaic） technology as an alternative means of energy generation experiences such significant energy decrease based on this condition which is due to the shading of sunlight. The 6 h claims of good sunlight has become not more than 2 h and gets worst when the API （air pollution index） struck 200 levels which is at very unhealthy condition. This study embraces some findings from 1 kWp PV generator field data installed in Malaysia reflecting the daily energy decrease operated during this unhealthy weather condition. It is found that, such significant energy decrease with the value of 0.43 W power output per increment of one point API. This value shows such concrete proof of additional factors to be considered in PV modelling in line to support PV technology adaptation in the ASEAN region.

汉景帝时代的“和亲”与“不和亲”

汉初起始的对匈奴的“和亲”,是处理边疆与民族问题适合时宜的政策。汉景帝时代是“和亲史”演进的重要阶段。汉景帝自即位起,就继承了汉文帝以来合理的边政措施,为争取和平的经济发展条件做出了努力。执政期间,在维持和亲关系的同时,与匈奴双方还有“通关市,给遗匈奴”等以汉王朝为主动方的经济联系,又有“不和亲”及匈奴贵族“来降”封侯的政策调整,甚至在局部地区,也发动了对匈奴的反击。汉景帝时的国力积累,为汉武帝时对匈奴军事压迫的解除做了充分的前期准备。而“郅将军击匈奴”,也可以看作后来大规模反击战的预演。对于中国古代各民族交往交流交融历史的认识、理解和说明,是否“顺其时”是一个合理判断的基点。

Water vapor δD dynamics over China derived from SCIAMACHY satellite measurements

This study investigates water vapor isotopic patterns and controls over China using high-quality water vapor δD data retrieved from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography （SCIAMACHY） observations. The results show that water vapor δD values on both annual and seasonal time-scales broadly exhibit a continental effect, with values largely decreasing northwestward from coastal lowlands to high-elevation mountainous regions. However, region-specific analysis reveals spatially distinct patterns of water vapor dD between seasons. In the monsoon domain （e.g., China south of 35~N）, depletion in D in the summer and fall seasons is closely tied to monsoon moisture sources （the Indian and Pacific oceans） and subsequent amount effect, but higher 8D values in winter and spring are a result of isotopically-enriched conti- nental-sourced moisture proceeded by less rainout. In contrast, farther inland in China （non-monsoon domain）, moisture is de- rived overwhelmingly from the dry continental air masses and local evaporation, and 8D values are largely controlled by the temperature effect, exhibiting a seasonality with isotopically enriched summer and depleted winter/spring. The observation that the spatial pattern of water vapor δD is the opposite to that of precipitation δD in the summer season also suggests that partial evaporation of falling raindrops is a key driver of water vapor isotope in the non-monsoon domain. This study highlights the importance of non-Rayleigh factors in governing water vapor isotope, and provides constraints on precipitation isotope inter- pretation and modern isotope hydrological processes over China.

Projection of climate extremes in China,an incremental exercise from CMIP5 to CMIP6

This paper presents projections of climate extremes over China under global warming of 1.5,2,and 3℃ above pre-industrial(1861–1900),based on the latest Coupled Model Intercomparison Project phase 6(CMIP6)simulations.Results are compared with what produced by the precedent phase of the project,CMIP5.Model evaluation for the reference period(1985–2005)indicates that CMIP6 models outperform their predecessors in CMIP5,especially in simulating precipitation extremes.Areal averages for changes of most indices are found larger in CMIP6 than in CMIP5.The emblematic annual mean temperature,when averaged over the whole of China in CMIP6,increases by 1.49,2.21,and 3.53℃(relative to1985–2005)for 1.5,2,and 3℃ above-preindustrial global warming levels,while the counterpart in CMIP5 is 1.20,1.93 and 3.39℃ respectively.Similarly,total precipitation increases by 5.3%,8.6%,and16.3%in CMIP6 and by 4.4%,7.0%and 12.8%in CMIP5,respectively.The spatial distribution of changes for extreme indices is generally consistent in both CMIP5 and CMIP6,but with significantly higher increases in CMIP6 over Northeast and Northwest China for the hottest day temperature,and South China for the coldest night temperature.In the south bank of the Yangtze River,and most regions around40°N,CMIP6 shows higher increases for both total precipitation and heavy precipitation.The projected difference between CMIP6 and CMIP5 is mainly attributable to the physical upgrading of climate models and largely independent from their emission scenarios.