Spatiotemporal variations of aridity index over the Belt and Road region under the 1.5℃ and 2.0℃ warming scenarios

Aridity index reflects the exchanges of energy and water between the land surface and the atmosphere, and its variation can be used to forecast drought and flood patterns, which makes it of great significance for agricultural production. The ratio of potential evapotranspiration and precipitation is applied to analyse the spatial and temporal distributions of the aridity index in the Belt and Road region under the 1.5℃ and 2.0℃ global warming scenarios on the basis of outputs from four downscaled global climate models. The results show that:(1) Under the 1.5℃ warming scenario, the area-averaged aridity index will be similar to that in 1986–2005(around 1.58), but the changes vary spatially. The aridity index will increase by more than 5% in Central-Eastern Europe, north of West Asia, the monsoon region of East Asia and northwest of Southeast Asia, while it is projected to decrease obviously in the southeast of West Asia. Regarding the seasonal scale, spring and winter will be more arid in South Asia, and the monsoon region of East Asia will be slightly drier in summer compared with the reference period. While, West Asia will be wetter in all seasons, except winter.(2) Relative to 1986–2005, both areal averaged annual potential evapotranspiration and precipitation are projected to increase, and the spatial variation of aridity index will become more obvious as well at the 2.0℃ warming level. Although the aridity index over the entire region will be maintained at approximately 1.57 as that in 1.5℃, the index in Central-Eastern Europe, north of West Asia and Central Asia will grow rapidly at a rate of more than 20%, while that in West Siberia, northwest of China, the southern part of South Asia and West Asia will show a declining trend. At the seasonal scale, the increase of the aridity index in Central-Eastern Europe, Central Asia, West Asia, South Asia and the northern part of Siberia in winter will be obvious, and the monsoon region in East Asia will be drier in both summer and autumn.(3) Under the scenario of an additional 0.5℃ increase in global temperature from 1.5℃ to 2.0℃, the aridity index will increase significantly in Central Asia and north of West Asia but decrease in Southeast Asia and Central Siberia. Seasonally, the aridity index in the Belt and Road region will slightly increase in all other seasons except spring. Central Asia will become drier annually at a rate of more than 20%. The aridity index in South Asia will increase in spring and winter, and that in East Asia will increase in autumn and winter.(4) To changes of the aridity index, the attribution of precipitation and potential evapotranspiration will vary regionally. Precipitation will be the major influencing factor over southern West Asia, southern South Asia, Central-Eastern Siberia, the non-monsoon region of East Asia and the border between West Asia and Central Asia, while potential evapotranspiration will exert greater effects over Central-Eastern Europe, West Siberia, Central Asia and the monsoon region of East Asia.     

三江源地区1961-2010年降水时空变化(英文)

Based on a monthly dataset of precipitation time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region (THRHR) of Qinghai Province, China, the spatio-temporal variation and abrupt change analysis of precipitation were examined by using moving average, linear regression, spline interpolation, the Mann-Kendall test and so on. Major conclusions were as follows. (1) The long-term annual and seasonal precipitation in the study area indicated an increasing trend with some oscillations during 1961-2010; however, the summer precipitation in the Lantsang (Lancang) River Headwater Region (LARHR), and the autumn precipitation in the Yangtze River Headwater Region (YERHR) of the THRHR decreased in the same period. (2) The amount of annual precipitation in the THRHR and its three sub-headwater regions was greater in the 1980s and 2000s. The springs were fairly wet after the 1970s, while the summers were relatively wet in the 1960s, 1980s and 2000s. In addition, the amount of precipitation in the autumn was greater in the 1970s and 1980s, but it was relatively less for the winter precipitation, except in the 1990s. (3) The normal values of spring, summer, winter and annual precipitation in the THRHR and its three sub-headwater regions all increased, but the normal value of summer precipitation in the LARHR had a negative trend and the normal value of winter precipitation declined in general. (4) The spring and winter precipitation increased in most of the THRHR. The summer, autumn and annual precipitation increased mainly in the marginal area of the west and north and decreased in the regions of Yushu, Zaduo, Jiuzhi and Banma. (5) The spring and winter precipitation in the THRHR and its three sub-headwater regions showed an abrupt change, except for the spring precipitation in the YARHR. The abrupt changes of spring precipitation were mainly in the late 1980s and early 1990s, while the abrupt changes of winter precipitation were primary in the mid-to late 1970s. This research would be helpful for further understanding the trends and periodicity of precipitation and for watershed-based water resource management in the THRHR.     

Research for length change of four seasons over China in recent 47 years

Using daily temperature data from 599 Chinese weather stations during 1961–2007, the length change trends of four seasons during the past 47 years were analyzed. Results show that throughout the region, four seasons’ lengths are: spring becomes shorter (-0.8 d/10yrs), summer becomes longer (3.2 d/10yrs), autumn (-0.5 d/10yrs) and winter (-1.6 d/10yrs) becomes shorter. This trend is different in spatial distribution, namely it is very obvious in northern than southern China, and also remarkable in eastern than western China. Summer change is most obvious, but autumn has little change comparatively. This trend is highly obvious in North, East, Central and South China. In the Southwest starting in the 21st century, summer becomes longer and winter shortens. The trend in the Plateau region since the 1980s is that spring becomes longer and winter shortens. The average annual temperature increased during the past 47 years, and the change of the average annual temperature precedes seasons’ length. Thus, the average annual temperature has a certain influence on the length change of seasons.     

基于格点数据的1961-2012年祁连山山区面雨量特征分析（英文）

Based on a 0.5°×0.5° daily gridded precipitation dataset and observations in meteorological stations released by the National Meteorological Information Center,the interannual variation of areal precipitation in the Qilian Mountains during 1961–2012 is investigated using principal component analysis(PCA) and regression analysis,and the relationship between areal precipitation and drought accumulation intensity is also analyzed.The results indicate that the spatial distribution of precipitation in the Qilian Mountains can be well reflected by the gridded dataset.The gridded data-based precipitation in mountainous region is generally larger than that in plain region,and the eastern section of the mountain range usually has more precipitation than the western section.The annual mean areal precipitation in the Qilian Mountains is 724.9×108 m3,and the seasonal means in spring,summer,autumn and winter are 118.9×108 m3,469.4×108 m3,122.5×108 m3 and 14.1×108 m3,respectively.Summer is a season with the largest areal precipitation among the four seasons,and the proportion in summer is approximately 64.76%.The areal precipitation in summer,autumn and winter shows increasing trends,but a decreasing trend is seen in spring.Among the four seasons,summer have the largest trend magnitude of 1.7×108 m3?a–1.The correlation between areal precipitation in the mountainous region and dry-wet conditions in the mountains and the surroundings can be well exhibited.There is a negative correlation between drought accumulation intensity and the larger areal precipitation is consistent with the weaker drought intensity for this region.     

Snow water equivalent over Eurasia in the next 50 years projected by aggregated CMIP3 models

Based on remote sensing snow water equivalent (SWE) data, the simulated SWE in 20C3M experiments from 14 models attending the third phase of the Coupled Models for Inter-comparison Project (CMIP3) was first evaluated by computing the different percentage, spatial correlation coefficient, and standard deviation of biases during 1979–2000. Then, the diagnosed ten models that performed better simulation in Eurasian SWE were aggregated by arithmetic mean to project the changes of Eurasian SWE in 2002–2060. Results show that SWE will decrease significantly for Eurasia as a whole in the next 50 years. Spatially, significant decreasing trends dominate Eurasia except for significant increase in the northeastern part. Seasonally, decreasing proportion will be greatest in summer indicating that snow cover in warmer seasons is more sensitive to climate warming. However, absolute decreasing trends are not the greatest in winter, but in spring. This is caused by the greater magnitude of negative trends, but smaller positive trends in spring than in winter. The changing characteristics of increasing in eastern Eurasia and decreasing in western Eurasia and over the Qinghai-Tibetan Plateau favor the viewpoint that there will be more rainfall in North China and less in the middle and lower reaches of the Yangtze River in summer. Additionally, the decreasing rate and extent with significant decreasing trends under SRES A2 are greater than those under SRES B1, indicating that the emission of greenhouse gases (GHG) will speed up the decreasing rate of snow cover both temporally and spatially. It is crucial to control the discharge of GHG emissions for mitigating the disappearance of snow cover over Eurasia.     

1961-2010年三江源地区气温变化与突变分析(英文)

In this study, a monthly dataset of temperature time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region of Qinghai Province (THRHR) was used to analyze the climate change. The temperature variation and abrupt change analysis were examined by using moving average, linear regression, Spline interpo-lation, Mann-Kendall test and so on. Some important conclusions were obtained from this research, which mainly contained four aspects as follows. (1) There were several cold and warm fluctuations for the annual and seasonal average temperature in the THRHR and its three sub-headwater regions, but the temperature in these regions all had an obviously rising trend at the statistical significance level, especially after 2001. The spring, summer, autumn and annual average temperature increased evidently after the 1990s, and the winter average temperature exhibited an obvious upward trend after entering the 21st century. Except the standard value of spring temperature, the annual and seasonal temperature standard value in the THRHR and its three sub-headwater regions increased gradually, and the upward trend for the standard value of winter average temperature indicated significantly. (2) The tendency rate of annual average temperature in the THRHR was 0.36℃10a?1, while the tendency rates in the Yellow River Headwater Region (YERHR), Lancangjiang River Headwater Region (LARHR) and Yangtze River Headwater Region (YARHR) were 0.37℃10a?1, 0.37℃10a?1 and 0.34℃10a?1 respectively. The temperature increased significantly in the south of Yushu County and the north of Nangqian County. The rising trends of temperature in winter and autumn were higher than the upward trends in spring and summer. (3) The abrupt changes of annual, summer, autumn and winter average temperature were found in the THRHR, LARHR and YARHR, and were detected for the summer and autumn average temperature in the YERHR. The abrupt changes of annual and summer average temperatures were mainly in the late 1990s, while the abrupt changes of autumn and winter average temperatures ap-peared primarily in the early 1990s and the early 21st century respectively. (4) With the global warming, the diversities of altitude and underlying surface in different parts of the Tibetan Plateau were possibly the main reasons for the high increasing rate of temperature in the THRHR.     

河北平原冬小麦播种面积收缩对农业水资源消耗的影响(英文)

This study firstly analyzed the shrinkage of winter wheat and the changes of cropping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calculated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1) The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×104ha. The shrinkage was most serious in the Beijing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2) The precipitation fill rate of winter wheat was only 20%–30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 mm. 3) The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×108m3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.     

Distribution of winter-spring snow over the Tibetan Plateau and its relationship with summer precipitation in Yangtze River

The distribution of winter-spring snow cover over the Tibetan Plateau(TP) and its relationship with summer precipitation in the middle and lower reaches of Yangtze River Valley(MLYRV) during 2003–2013 have been investigated with the moderate-resolution imaging spectrometer(MODIS) Terra data(MOD10A2) and precipitation observations. Results show that snow cover percentage(SCP) remains approximately 20% in winter and spring then tails off to below 5% with warmer temperature and snow melt in summer. The lower and highest percentages present a declining tendency while the middle SCP exhibits an opposite variation. The maximum value appears from the middle of October to March and the minimum emerges from July to August. The annual and winter-spring SCPs present a decreasing tendency. Snow cover is mainly situated in the periphery of the plateau and mountainous regions, and less snow in the interior of the plateau, basin and valley areas in view of snow cover frequency(SCF) over the TP. Whatever annual or winter-spring snow cover, they all have remarkable declining tendency during 2003–2013, and annual snow cover presents a decreasing trend in the interior of the TP and increasing trend in the periphery of the TP. The multi-year averaged eight-day SCP is negatively related to mean precipitation in the MLYRV. Spring SCP is negatively related to summer precipitation while winter SCP is positively related to summer precipitation in most parts of the MLYRV. Hence, the influence of winter snow cover on precipitation is much more significant than that in spring on the basis of correlation analysis. The oscillation of SCF from southeast to northwest over the TP corresponds well to the beginning, development and cessation of the rain belt in eastern China.     

1910-2014年湖南省均一化气温序列构建及其变化特征（英文）

Based on the statistical method and the historical evolution of meteorological stations,the temperature time series for each station in Hunan Province during 1910–2014 are tested for their homogeneity and then corrected.The missing data caused by war and other reasons at the 8 meteorological stations which had records before 1950 is filled by interpolation using adjacent observations,and complete temperature time series since the establishment of stations are constructed.After that,according to the representative analysis of each station in different time periods,the temperature series of Hunan Province during 1910–2014 are built and their changes are analyzed.The results indicate that the annual mean temperature has a significant warming trend during 1910–2014 and the seasonal mean temperature has the largest rising amplitude in winter and spring,followed by autumn,but no significant change in summer.Temperature variation over Hunan Province has several significant warm-cold alternations and more frequent than that in whole China.Annual and seasonal mean temperatures except summer and autumn have abrupt warming changes in the recent 100 years.The wavelet analysis suggests that the annual and four seasonal mean temperatures in recent 100 years have experienced two climatic shifts from cold to warm.     

Impact of the shrinking winter wheat sown area on agricultural water consumption in the Hebei Plain简

This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calcu- lated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1） The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×10^4 ha. The shrinkage was most serious in the Bei- jing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2） The precipitation fill rate of winter wheat was only 20%-30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 ram. 3） The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×10^8 m^3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.     

Seasonal variation in dust events and the causes of the variation in the Tarim Basin, China

We analyzed dust event occurrence and its seasonal distribution at 16 sites in the Tarim Basin,China.Although the overall frequency of dust events was the highest in spring in this region,its variation in other seasons could be classified into three patterns:(1) frequency of dust events in autumn > that in summer > that in winter(at the Kashi and Kuche sites);(2) frequency in summer > that in winter > that in autumn(at the Ruoqiang site);and(3) frequency in summer > that in autumn > that in winter(at all other areas of the Tarim Basin).The frequency of dust events and their seasonal variations in the Tarim Basin were mainly controlled by wind speed and locally available dust sources;the former was the key control when dust sources did not differ significantly.The seasonal variation in evaporation had a smaller,but still significant effect on the frequency of dust events.     

Temporal variations in aerosol composition at Lanzhou City,Northwestern China

Although Lanzhou is one of the most heavily polluted cities in China, the composition of its air pollutants have not yet been studied in detail. The data of four months on the concentrations and compositions of ions from daily air-filter samples in the winter and spring during 2007–2008 were analyzed to investigate temporal trends and their possible causes. The results indicate that mean concentrations of almost all the aerosol components are greater in winter than in spring due to stronger emissions in winter and weaker localized dispersion. Spring dust storms are the major cause of the highest peak PM10 concentrations recorded during the study period; however, these elevated levels were transient. Ion concentrations related to coal combustion show the greatest reduction from winter to spring, while the concentrations of strong crustal components show a less-pronounced reduction. Strong cycles in the levels of particulate matter (PM) and all ions are also observed during the winter months due to meteorological conditions. Depending on the season, nine different ions accounted for 20%–50% of the PM concentration. The particle size of polluting ions was constant at times of increasing PM concentrations (particularly during winter), whereas the particle size of crustal ions increased dramatically during spring dust storms. Local meteorological conditions (especially wind speed) have a strong influence on the levels of pollutants. Four dust storms were noted, including one during winter. In summary, the regional transport of desert dust from the Gobi can significantly affect air quality and the chemical composition of aerosols in Lanzhou. The dust storms can strongly increase concentration of crustal ions, which are characteristics of deserts in northwestern China. This observation is in agreement with back-trajectories, which show reduced levels of pollutant ions during dust storms. Data on nitrate:sulfate ratios indicate that stationary point sources are the main source of ions rather than mobile sources.     

Hydrological effects of alpine permafrost in the headwaters of the Urumqi River, Tianshan Mountains

Against the background of climate change, alpine permafrost active layers have shown a gradual thickening trend and the hydrothermal conditions have undergone significant changes in the Tianshan Mountains and the Qinghai-Tibet Plateau, China. At the ice-free cirque basins in the headwaters of the Urumqi River(hereafter referred to as the Ice-Free Cirque) in eastern Tianshan, China, the hydrological effects of the alpine permafrost active layers appear to have also exhibited significant changes recently. The increasing trend of local precipitation is clear in May and June. The onset of winter and spring snowmelt runoff clearly lags behind increases of air temperature, and the runoff peak appears near the beginning of the melting season, which results in the spring runoff increasing. In summer, runoff decreases strongly and the maximum runoff occurs earlier. In our analysis of meteorological and hydrologic data from 1959 to 2010, the runoff and precipitation changes are significantly correlated. In the initial stage of runoff, the runoff-producing process is mainly under the control of the soil water content and soil temperature in the 0–30 cm active layers. Spring precipitation and snowmelt water are mainly involved in the processes of infiltration and evaporation while some melt water infiltrates into the seasonal thawed layer and stays above the frozen layers. During the strong ablation period in summer, the runoff-generating process is mainly controlled by soil water content in the active layers deeper than 60 cm. In the active layer, precipitation and seasonal snowmelt water infiltrates, migrates, collects, and then forms runoff.     

Responses to climate warming of hydrological processes in the upper Kelan River in the Altay Mountains, Xinjiang, China

Kelan River is a branch of the Ertix River, originating in the Altay Mountains in Xinjiang, northwestern China. The upper streams of the Kelan River are located on the southern slope of the Altay Mountains; they arise from small glacial lakes at an elevation of more than 2,500 m. The total water-collection area of the studied basin, from 988 to 3,480 m, is about 1,655 km2. Almost 95 percent of the basin area is covered with snow in winter. The westerly air masses deplete nearly all the moisture that comes in the form of snow during the winter months in the upper and middle reaches of the basin. That annual flow from the basin is about 382 mm, about 45 percent of which is contributed by snowmelt. The mean annual precipitation in the basin is about 620 mm, which is primarily concentrated in the upper and middle basin. The Kelan River system could be vulnerable to climate change because of substantial contribution from snowmelt runoff. The hydrological system could be altered significantly because of a warming of the climate. The impact of climate change on the hydrological cycle and events would pose an additional threat to the Altay region. The Kelan River, a typical snow-dominated watershed, has more area at higher elevations and accumulates snow during the winter. The peak flow occurs as a result of snow-melting during the late spring or early summer. Stream flow varies strongly throughout the year because of seasonal cycles of precipitation, snowpack, temperature, and groundwater. Changes in the temperature and precipitation affect the timing and volume of stream-flow. The stream-flow consists of contributions from meltwater of snow and ice and from runoff of rainfall. Therefore, it has low flow in winter, high flow during the spring and early summer as the snowpack melts, and less flows during the late summer. Because of the warming of the current climate change, hydrology processes of the Kelan River have undergone marked changes, as evidenced by the shift of the maximum flood peak discharge from May to June     

雅鲁藏布江流域1961-2005年气候变化趋势

The Yarlung Zangbo River (YR) is the highest great river in the world, and its basin is one of the centers of human economic activity in Tibet. Using 10 meteorological stations over the YR basin in 1961–2005, the spatial and temporal characteristics of temperature and precipitation as well as potential evapotranspiration are analyzed. The results are as follows. (1) The annual and four seasonal mean air temperature shows statistically significant increasing trend, the tendency is more significant in winter and fall. The warming in Lhasa river basin is most significant. (2) The precipitation is decreasing from the 1960s to the 1980s and increasing since the 1980s. From 1961 to 2005, the annual and four seasonal mean precipitation is increasing but not statistically significant, especially in fall and spring. The increasing precipitation rates are more pronounced in Niyangqu and Palong Zangbo river basins, the closer to the upper YR is, the less precipitation increasing rate would be. (3) The annual and four seasonal mean potential evapotranspiration has decreased, especially after the 1980s, and most of it happens in winter and spring. The decreasing trend is most significant in the middle YR and Nianchu river basin. (4) Compared with the Mt. Qomolangma region, Tibetan Plateau, China and global average, the magnitudes of warming trend over the YR basin since the 1970s exceed those areas in the same period, and compared with the Tibetan Plateau, the magnitudes of precipitation increasing and potential evapotranspiration decreasing are larger, suggesting that the YR basin is one of the most sensitive areas to global warming.     

Assessing changes in extreme precipitation over Xinjiang using regional climate model of PRECIS

In this paper, an analysis, with the simulation of PRECIS(Providing Regional Climate for Impact Studies), was made for future precipitation extremes, under SRES(Special Report on Emission Scenarios) A2 and B2 in IPCC(Intergovernmental Panel on Climate Change) AR4. The precipitation extremes were calculated and analyzed by ETCCDI(Climate Change Detection and Indices). The results show that:(1) In Present Scenario(1961–1900), PRECIS could capture the spatial pattern of precipitation in Xinjiang.(2) The simulated annual precipitation and seasonal precipitation in Xinjiang had a significantly positive trend and its variability had been deeply impacted by terrain. There was a strong association between increasing trend and the extreme precipitation's increase in frequency and intensity during 1961–2008. Under SRES A2 and B2, extreme precipitation indicated an increasing tendency at the end of the 21 st century. The extreme summer precipitation increased prominently in a year.(3) PRECIS's simulation under SRES A2 and B2 indicated increased frequency of heavy precipitation events and also enhancement in their intensity towards the end of the 21 st century. Both A2 and B2 scenarios show similar patterns of projected changes in precipitation extremes towards the end of the 21 st century. However, the magnitude of changes in B2 scenario was on the lower side. In case of extreme precipitation, variation between models can exceed both internal variability and variability of different SRES.     

1976–2010年波兰湖泊水位变化（英文）

The paper presents the analysis of tendencies in water level changes in 32 lakes in Poland during 1976–2010.Series of monthly,seasonal,and annual precipitation and air temperature for 9 meteorological stations were also studied.The trend analysis for all of the studied series of water levels in lakes showed high spatial and temporal variability.Series of annual water levels in the case of 6 lakes showed statistically significant increasing tendencies,and in 7 lakes,significant decreasing trends.Series of annual amplitudes in the majority of lakes(22) showed a decreasing trend,but they were statistically significant only in three cases.The tendencies for air temperature fluctuations are more statistically significant than precipitation.The key role in determining water level changes is played by local factors,particularly including human economic activity,obscuring the effect of natural factors on water level changes.The paper describes cases of changes in water levels in lakes under anthropopressure related to among others: agricultural irrigations,hydropower infrastructure,water transfers,navigation,or mining.     

西南地区冬季气温和降水的时空变化

In recent years,the socio-economic impacts of winter extreme climate events have underscored the importance of winter climate anomalies in Southwest China (SWC).The spatio-temporal variability of surface air temperature (SAT) and precipitation in SWC and their possible causes have been investigated in this paper based on observational data from 1961 to 2010.The results indicate that SAT anomalies in SWC have two dominate modes,one is homogenous,and the other a zonal dipole.The former is caused by the anomalies of East Asian winter monsoon;the latter arises from the anomalies of both subtropical west Pacific high and regional cold air in lower troposphere.The most dominant mode of precipitation anomalies in SWC is homogenous and it has a high correlation with northern hemisphere annular mode (NAM,AO).Neither NAM nor ENSO has significant impacts on SAT in SWC.The anomalies of NAM are associated with the anomalies of tropical circulations,and there-fore precipitation over the SWC.When NAM is in positive (negative) phase,the winter pre-cipitation is more (less) than normal in SWC.Winter precipitation increase over the whole SWC is associated with the El Nino.However,during La Nina winter,the pattern is not uni-form.There is an increase in precipitation over the central parts and a decrease in western and eastern parts of SWC.The severe drought in SWC in winter 2010 is more likely caused by anomalies of NAM,not El Nino.     

新疆气候时空变化特征及其趋势(英文)

Temperature and precipitation time series datasets from 1961 to 2005 at 65 meteorological stations were used to reveal the spatial and temporal trends of climate change in Xinjiang, China. Annual and seasonal mean air temperature and total precipitation were analyzed using Mann-Kendall (MK) test, inverse distance weighted (IDW) interpolation, and R/S methods. The results indicate that: (1) both temperature and precipitation increased in the past 45 years, but the increase in temperature is more obvious than that of precipitation; (2) for temperature increase, the higher the latitude and the higher the elevation the faster the increase, though the latitude has greater influence on the increase. Northern Xinjiang shows a faster warming than southern Xinjiang, especially in summer; (3) increase of precipitation occurs mainly in winter in northern Xinjiang and in summer in southern Xinjiang. Ili, which has the most precipitation in Xinjiang, shows a weak increase of precipitation; (4) although both temperature and precipitation increased in general, the increase is different inside Xinjiang; (5) Hurst index (H) analysis indicates that climate change will continue the current trends.     

内蒙古西部阿拉善沙漠地区末次冰盛期和全新世中期的水汽来源——依据现代气象过程、古气候模拟和地质记录的综合解译（英文）

Knowledge of moisture sources is of great significance for understanding climatic change and landscape evolution in desert environments. In this paper, we aim to clarify moisture origins for the Alashan(Alxa) Sand Seas(ALSS) in western Inner Mongolia and their transport pathways during the Last Glacial Maximum(LGM) and the mid-Holocene using modern analogues and paleoclimatic simulations. Precipitation data for the period 1959–2015 from meteorological stations in the study area and wind and specific humidity data from the European Center for Medium-Range Weather Forecasts(ECMWF) daily reanalysis were adopted to determine the moisture sources of summer precipitation in the ALSS. In addition paleoclimate simulations under PMIP3/CMIP5 protocols were used to detect the atmospheric circulation and precipitation at 21 ka BP and 6 ka BP over the ALSS. We also reviewed paleoclimate records from the ALSS to acquire a semi-quantitative reconstruction of the moisture history during the late Pleistocene and Holocene. Our results suggest that the summer monsoon transported water vapor from the Indian Ocean and the South China Sea to the ALSS during July and August, causing increased precipitation. The dominant moisture source was from the southwest monsoon, while the East Asian summer monsoon also partly contributed to precipitation in the ALSS. The increased humidity during the period 8.2–4.2 ka BP in the ALSS, as derived from both climate simulation outputs and sedimentary records, was caused by monsoons according to the outputs of simulations. At 21 ka BP, the moisture sources of the ALSS were greatly associated with the prevailing westerlies.