三个全球气候模式对中国气温季节变化模拟能力的空间差异特征分析

针对第五次国际耦合模式比较计划（CMIP5）中3个全球气候模式对中国气温季节变化模拟能力的空间差异特征进行具体分析。结果表明：BCC-CSM1.1（m）模式和GFDL-CM3模式能够再现中国气温的季节性变化,在中国东部地区模拟能力较强,平均绝对误差和均方根误差均较小,在中国西部地区模拟能力较弱,平均绝对误差和均方根误差较大。与BCC-CSM1.1（m）和GFDL-CM3模式相比,HADGEM2-ES模式再现中国地区气温季节变化的能力最弱,平均绝对误差和均方根误差在西部部分地区、内蒙古地区和东北地区较大,在华南地区南部较小。在相同模式下,日平均气温模拟效果最好,其次是日最低气温,日最高气温模拟效果最差。纬度、经度、海拔和坡度对气候模式模拟效果的影响存在模式间的差异,而坡向和地形遮蔽度对模式的模拟效果无明显影响。     

Temperature and precipitation changes in Extensive Hexi Region,China, 1960–2011

Global climate change has been evident in many places worldwide. This study provides a better understanding of the variability and changes in frequency, intensity, and duration of temperature, precipitation, and climate extremes in the Extensive Hexi Region, based on meteorological data from 26 stations. The analysis of average, maximum, and minimum temperatures revealed that statistically significant warming occurred from 1960 to 2011. All temperature extremes displayed trends consistent with warming, with the exception of coldest-night temperature(TNn) and coldest-day temperature(TXn), which were particularly evident in high-altitude areas and at night. Amount of precipitation and number of rainy days slowly increased with no significant regional trends, mainly occurring in the Qilian Mountains and Hexi Corridor. The significance of changes in precipitation extremes during 1960–2011 was high, but the regional trends of maximum 5-day precipitation(RX5day), the average precipitation on wet days(SDII), and consecutive wet days(CWD) were not significant. The variations in the studied parameters indicate an increase in both the extremity and strength of precipitation events, particularly in higher-altitude regions. Furthermore, the contribution from very wet precipitation(R95) and extremely wet precipitation(R99) to total precipitation also increased between 1960 and 2011. The assessment of these changes in temperature and precipitation may help in developing better management practices for water resources. Future studies in the region should focus on the impact of these changes on runoffs and glaciers.     

Changes in production potentials of rapeseed in the Yangtze River Basin of China under climate change: A multi-model ensemble approach

Rapeseed is one of the major oil crops in China and it is very sensitive to climate change. The Yangtze River Basin is the main rapeseed production area in China. Therefore, a better understanding of the impact of climate change on rapeseed production in the basin is of both scientific and practical importance to Chinese oil industry and food security. In this study, based on climate data from 5 General Circulation Models (GCMs) with 4 representative concentration pathways (RCPs) in 2011–2040 (2020s), 2041–2070 (2050s) and 2071–2100 (2080s), we assessed the changes in rapeseed production potential between the baseline climatology of 1981–2010 and the future climatology of the 2020s, 2050s, and 2080s, respectively. The key modelling tool – the AEZ model – was updated and validated based on the observation records of 10 representative sites in the basin. Our simulations revealed that: (1) the uncertainty of the impact of climate change on rapeseed production increases with time; (2) in the middle of this century (2050s), total rapeseed production would increase significantly; (3) the average production potential increase in the 2050s for the upper, middle and lower reaches of the Yangtze River Basin is 0.939, 1.639 and 0.339 million tons respectively; (4) areas showing most significant increases in production include southern Shaanxi, central and eastern Hubei, northern Hunan, central Anhui and eastern Jiangsu.     

Wavelet analysis of quasi-3-year temperature oscillations in China in last 50 years, and predicted changes in the next 20 years

The wavelet analysis method is used to analyze the annual and winter temperature data of 98 observation stations in China in eight climate zones during the last 50 years （1961-2009）. The periodicities of temperature changes are investigated, and the possible temperature change trends in China in the next 20 years （2012-2029） are also predicted. Our results show that in the inter-annual temperature variability there are pervasive quasi-3- to quasi-4-year cycles, and these cycle changes are relatively steady. The periodic characteristics of the annual temperature changes are clearly different between northern and southern China, and our period superimposition extrapolation shows that both annual and winter temperatures in China will continue to increase in the next 20 years, more so in northern China and in the Qinghai-Xizang Plateau （QXP） than in the southern region, except in the southwest. If temperatures follow historic increasing linear trends, the overall temper- ature is expected to increase by 1℃ between 2010 and 2029.     

Change analysis of rice area and production in China during the past three decades

Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.     

Characteristics of permafrost degradation in Northeast China and its ecological effects: A review

Latitudinal permafrost in Northern Northeast(NNE)China is located in the southern margin of the Eurasian continent,and is very sensitive to climatic and environmental change.Numerical simulations indicate that air temperature in the permafrost regions of Northeast China has been on the rise since the 1950s,and will keep rising in the 21st century,leading to extensive degradation of permafrost.Permafrost degradation in NNE China has its own characteristics,such as northward shifts in the shape of a"W"for the permafrost southern boundary(SLP),discontinuous permafrost degradation into islandlike frozen soil,and gradually disappearing island permafrost.Permafrost degradation leads to deterioration of the ecological environment in cold regions.As a result,the belt of larch forests dominated by Larix gmelinii has shifted northwards and wetland areas with symbiotic relationships with permafrost have decreased significantly.With rapid retreat and thinning of permafrost and vegetation change,the CO2 and CH4 flux increases with mean air temperature from continuous to sporadic permafrost areas as a result of activity of methanogen enhancement,positively feeding back to climate warming.This paper reviews the features of permafrost degradation,the effects of permafrost degradation on wetland and forest ecosystem structure and function,and greenhouse gas emissions on latitudinal permafrost in NNE China.We also put forward critical questions about the aforementioned effects,including:(1)establish long-term permafrost observation systems to evaluate the distribution of permafrost and SLP change,in order to study the feedback of permafrost to climate change;(2)carry out research about the effects of permafrost degradation on the wetland ecosystem and the response of Xing'an larch to global change,and predict ecosystem dynamics in permafrost degradation based on long-term field observation;(3)focus intensively on the dynamics of greenhouse gas flux in permafrost degradation of Northeast China and the feedback of greenhouse gas emissions to climate change;(4)quantitative studies on the permafrost carbon feedback and vegetation carbon feedback due to permafrost change to climate multi-impact and estimate the balance of C in permafrost regions in the future.     

A study on the possible impacts of climate warming on rice production in China

IntroductionBecauseoftherapidindustrialiZation,eSPeciallytheuseoffossilfijels,atmosphericconcentrahonofgreenhousegases,suchascabindioxide(CO2)andotherradiahvelyachvetracegases,haveincreasedconsiderablyinthepastcentury,thatwouldinducetoagradualw~ngoftheplanetthroughgreenhouseeffectS[l'2].TheincreaseofCOZconcenhationintheatmosphereanditSinducedclimatechangewouldimpactonagricultUlalproduchonbothdireehyandindirectly'"1.faceisoneofthemostimportantcropsforfoodproduchonintheworld.faceproduchoninC…     

中国西北干旱半干旱区年平均气温的时空变化规律分析

利用中国西北干旱区138个测站,近46年历年平均地面月气温资料,采用线性趋势分析、多项式拟合、EOF、REOF、Mann-Kendall、子波分析等方法,分析了干旱区年平均气温对气候变暖的响应.结果表明:(1)中国西北干旱半干旱区年平均气温近46年增温率为0.34℃/10 a.新疆西部、青海高原东部的部分地方受大地形背风坡影响有不显著的上升趋势,其余大部分区域增温显著,同步响应全球变暖.(2)年平均气温标准差分布不均匀.除南疆和海东-陇南-带相对较小,该区其余大部分区域年平均气温的年际变化稳定性差.(3)蒙陕甘宁-塔里木盆地是该区气温变化最敏感的区域.年平均气温的演变在干旱半干旱区一致性程度较高.从20世纪70年代初期开始发生降温-升温转型,1986年有一次显著突变,其后气温达到一个更显著的增暖时期;全区性的前10个偏热年,全部出现在20世纪90年代及以后,各分区的异常偏热年,大多数也出现在1990年以后;气温异常变化存在5年和10年左右的周期,从15年以上的变化层次来看,气温趋势还在偏高的位置.(4)年平均气温存在演变的地域差异,蒙新区和陕甘宁青区南北变化相反.(5)根据REOF分析将该区年平均气温异常细分为北部区、高原区、南疆区和东部区4个分区.西部干旱半干旱区年平均气温的转折存在区域差异,高原和南疆区单调增暖,无明显转折,北部区的转暖时间比较低纬度的东部大致要早5年左右.受高原"启动区"影响,其它区的突变比高原要晚3～10年,其它区的年代际变化比高原要晚1～2年.     

Spatiotemporal changes in frequency and intensity of high-temperature events in China during 1961–2014

In this study, we explored spatial patterns and the temporal trends in high-temperature events (HTEs) for the mainland of China during 1961–2014 based on a daily- maximum surface-air-temperature dataset of 494 stations and nonparametric trend detection methods. With three thresholds of 35°C (HTE35), 37°C (HTE37), and 40°C (HTE40), HTEs occurred in 82%, 71%, and 37% of the surveyed stations and showed an overall increasing trend in both frequency and intensity during 1961–2014. In northern and southeastern China, HTEs showed a significant increasing trend in both frequency and intensity, whilst a decreasing trend for both was observed in central China. Despite such regional heterogeneity, HTEs overwhelmingly presented three-phase characteristics in all three representative regions and throughout China; the phases are 1961–1980, 1980–1990, and 1990–2014. Both frequency and intensity of HTEs have strongly increased during 1990–2014 at 54.86%, 48.38%, and 23.28% of the investigated stations for HTE35, HTE37 and HTE40, respectively. These findings implied that HTEs adaptation should be paid further attention in the future over China because the wide spread distribution of HTEs and their increasing trends in both frequency and intensity during recent decades might pose challenges to the sustainability of human society and the ecosystem.     

Remote sensing detection of glacier changes in Tianshan Mountains for the past 40 years

Both marginal fluctuation and areal change were used to detect the accurate dynamics of glacier change in the study area using Landsat MSS, ETM, SPOT HRV and topographic maps based on GIS. From 1963 to 1977, four of eight glaciers advanced, two of them retreated and another two kept stable, the glacier advanced generally. From 1977 to 1986, four of eight glaciers retreated and the others kept stable, but the retreated glaciers were those which advanced from 1963 to 1977. From 1986 to 2000, seven of eight glaciers retreated and only one glacier kept stable, the retreating velocity was 10-15 m/a. Glacier recession in this period became very fast and universal. From 1963 to 2000, the area of glaciers decreased from 5479.0 ha to 4795.4 ha, up to 12.5%. It is alarming that most of glacier retreats happened from 1986 to 2000. This was very consistent with change process of summer mean temperature in this region and global warming beginning in the 1980s.     

中国不同气候区多源遥感降水融合与性能综合评估

遥感降水产品种类繁多,单一遥感降水产品难以满足所有气候区的降水估算。多源遥感降水融合方法可弥补这一缺陷,进而提高降水估算精度。本研究选择四种全球典型遥感降水产品（CHIRPS v2.0、CMORPH v1.0、PERSIANN-CDR、TRMM 3B42V7）,利用集成模型输出统计（EMOS）进行数据融合,并与均值（MME）对比分析,阐明遥感降水产品和EMOS,在不同气候区的基本统计性能（BIAS、RMSE、r和KGE）、等级性能（POD）和水文性能（NSE）。结果发现：① 四种遥感降水产品均能捕获多年降水的空间分布格局,但EMOS改进了遥感降水产品整体低估现象。相对于MME,EMOS显著地（P<0.05）减小了4个气候区的BIAS,减小全国降水BIAS和RMSE分别为36.9%和10.2%。全国尺度而言,EMOS提高r和KGE分别为18.2%和71.4%。② PERSIANN-CDR中寒旱区微量降雨的POD高于其他三种产品,但是对大雨的POD低于其他产品。EMOS对微量降雨POD的提高出现在干旱区和青藏高原,对中雨POD则在过渡区和湿润区,而对小雨则适用于全国各气候区。③ TRMM 3B42V7的径流模拟能力优于其他三种遥感降水产品,表现最差的为CHIRPS v2.0产品。相对MME而言,除过渡区外,EMOS均提高了其他气候区的水文模拟性能,且在青藏高原、干旱区和湿润区的NSE分别提高26.3%、8.5%和2.2%。研究结果不仅为遥感降水产品在不同气候区数据源的选择提供参考依据,而且为多源遥感降水数据的融合和应用开拓了新思路。     

Climate transformation to warm-humid and its effect on river runoff in the source region of the Yellow River

The change characteristics and trends of the regional climate in the source region of the Yellow River, and the response of runoff to climate change, are analyzed based on observational data of air temperature, precipitation, and runoff at 10 main hydrological and weather stations in the region. Our results show that a strong signal of climate shift from warm-dry to warm-humid in the western parts of northwestern China （Xinjiang） and the western Hexi Corridor of Gansu Province occurred in the late 1980s, and a same signal of climate change occurred in the mid-2000s in the source region of the Yellow River located in the eastern part of northwestern China. This climate changeover has led to a rapid increase in rainfall and stream runoff in the latter region. In most of the years since 2004 the average annual precipitation in the source region of the Yellow River has been greater than the long-term average annual value, and after 2007 the runoff measured at all of the hydrologic sections on the main channel of the Yellow River in the source region has also consistently exceeded the long-term average annual because of rainfall increase. It is difficult to determine the prospects of future climate change until additional observations and research are conducted on the rate and temporal and spatial extents of climate change in the region. Nevertheless, we predict that the climate shift from warm-dry to warm-humid in the source region of the Yellow River is very likely to be in the decadal time scale, which means a warming and rainy climate in the source region of the Yellow River will continue in the coming decades.     

近40年天山冰川变化的遥感监测

Both marginal fluctuation and areal change were used to detect the accurate dynamics of glacier change in the study area using Landsat MSS, ETM, SPOT HRV and topographic maps based on GIS. From 1963 to 1977, four of eight glaciers advanced, two of them retreated and another two kept stable, the glacier advanced generally. From 1977 to 1986, four of eight glaciers retreated and the others kept stable, but the retreated glaciers were those which advanced from 1963 to 1977. From 1986 to 2000, seven of eight glaciers retreated and only one glacier kept stable, the retreating velocity was 10-15 m/a. Glacier recession in this period became very fast and universal. From 1963 to 2000, the area of glaciers decreased from 5479.0 ha to 4795.4 ha, up to 12.5%. It is alarming that most of glacier retreats happened from 1986 to 2000. This was very consistent with change process of summer mean temperature in this region and global warming beginning in the 1980s.     

Contrasting vegetation changes in dry and humid regions of the Tibetan Plateau over recent decades

An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and associated drivers remain to be explored. This study used a satellite Leaf Area Index(LAI) dataset(the GLASS LAI dataset) and examined vegetation changes in humid and arid regions of the TP during 1982–2012. Based on distributions of the major vegetation types, the TP was divided roughly into a humid southeastern region dominated by meadow and a dry northwestern region covered mainly by steppe. It was found that the dividing line between the two regions corresponded well with the lines of mean annual precipitation of 400 mm and the mean LAI of 0.3. LAI=0.3 was subsequently used as a threshold for investigating vegetation type changes at the interanual and decadal time scales: if LAI increased from less than 0.3 to greater than0.3 from one time period to the next, it was regarded as a change from steppe to meadow, and vice versa. The analysis shows that changes in vegetation types occurred primarily around the dividing line of the two regions, with clear growth(reduction) of the area covered by meadow(steppe), in consistency with the findings from using another independent satellite product. Surface air temperature and precipitation(diurnal temperature range) appeared to contribute positively(negatively) to this change though climate variables displayed varying correlation with LAI for different time periods and different regions.     

1906-2015年武汉市温度变化序列重建与初步分析

本文利用1906-2015年武汉月平均最高与最低气温资料,重建了过去110年武汉市年平均气温距平序列,分析了其年代际尺度的变化特征。主要结论为：①过去110年武汉市经历了“暖—冷—暖”3个多年代际波动,其中1906-1946年与1994-2015年气候相对温暖,1947-1993年则气候相对寒冷;②在多年代尺度上,武汉市存在多次显著增温和降温过程,其中增温速率最快的30年和50年分别出现在1980-2009年和1960-2009年;最快降温速率则出现在1928-1957年和1925-1974年;③过去110年武汉市年均温发生了3次跃变,其中由冷转暖的跃变出现在20世纪20年代初和90年代中后期,而由暖转冷的跃变则出现在40年代;④武汉市年均温变化与全球/北半球和中国的变化趋势基本一致,但变幅偏大。此外,全球增暖停滞现象在武汉市最近十几年也有所体现。     

基于全球模式对中国极端气温指数模拟的评估

对IPCC 所提供的7 个全球海气耦合模式输出信息(年霜冻日数、生物生长季、温度 年较差、暖夜指数、热浪指数), 利用同期(1961-2000 年) 中国地区极端气温观测资料检测并 评价模式的预估效能。结果表明, 这些模式对中国地区的极端气温都具有一定的模拟能力, 但同时各个模式的模拟场都有各自的系统误差; 综合评价, 在7 个模式中GFDL-CM2.0 和 MIROC3.2 (hires) 两个模式对中国区域极端气温的模拟效果均为最佳。模拟所得的最优指数 为霜冻日数, 其后依次为: 暖夜指数、热浪指数、气温年较差和生物生长季; 而就空间分布 结构来看, 除暖夜指数的模拟效果较差之外, 其余指数均能较好地模拟出其空间分布特征。     

基于Biome-BGC模型的青藏高原五道梁地区NPP变化及情景模拟

以“气候变暖”为标志的全球气候变化对青藏高原生态系统产生强烈影响,利用参数本地化的生物地球化学模型（Biome-BGC）对五道梁地区草地生态系统进行模拟,研究了该区域1961~2015年净初级生产力（net primary productivity,NPP）的变化,并进行了情景模拟。结果表明:五道梁地区近55 a草地年均NPP为67.94 g/(m ²·a),呈显著上升趋势,主要是由生长季延长以及9月份生物量快速增长造成。在该地区,温度是草地NPP的主导因子,降水变化在40%以内对生产力影响不显著;温度和降水交互影响NPP,对单一影响有放大作用,暖湿条件下NPP对气候变化响应更加明显。     

背景气候和城市化对中国东南部增温的联合效应(英文)

Based on China homogenized land surface air temperature and the National Centers for Environmental Prediction/Department of Energy (NCEP/DOE) Atmospheric Model Intercomparison Project (AMIP)-Ⅱ Reanalysis data (R-2), the main contributors to surface air temperature increase in Southeast China were investigated by comparing trends of urban and rural temperature series, as well as observed and R-2 data, covering two periods of 1954-2005 and 1979-2005. Results from urban-rural comparison indicate that urban heat island (UHI) effects on regional annual and autumn minimum temperature increases account for 10.5% and 12.0% since 1954, but with smaller warming attribution of 6.2% and 10.6% since 1979. The results by comparing observations with R-2 surface temperature data suggest that land use change accounts for 32.9% and 28.8% in regional annual and autumn minimum temperature increases since 1979. Accordingly, the influence of land use change on regional temperature increase in Southeast China is much more noticeable during the last 30 years. However, it indicates that UHI effect, overwhelmed by the warming change of background climate, does not play a significant role in regional warming over Southeast China during the last 50 years.     

中国绿洲喜温作物气候生长期对全球变暖停滞响应的时空差异

基于中国绿洲喜温作物分布区67个地面气象站1960—2016年逐日平均气温数据,运用线性趋势法、反距离加权(IDW)、Morlet小波分析法、Mann-Kendall检验等方法,分析了中国绿洲喜温作物气候生长期生长初、终日及生长期的时空变化对全球变暖停滞(globe warming hiatus)的响应。结果表明:1998—2012年中国绿洲喜温作物气候生长期生长初、终日及生长期变化倾向率分别为:-2.15d·(10 a)-1、2.76 d·(10 a)-1、4.91 d·(10 a)-1,与1960—2016年和1960—1998年相比呈现出初日提前、终日推迟、生长期延长的态势,没有出现对全球变暖停滞的响应;空间变化方面,仅有超过22%的站点有对全球变暖停滞的响应,整体响应不显著;但各绿洲对全球变暖停滞的响应却不尽相同,柴达木绿洲喜温作物气候生长期对全球变暖停滞的响应最为显著,其余绿洲则反之,也反映了青藏高原是气候变化的驱动器与放大镜。突变分析显示,研究区喜温作物生长初日、终日及生长期分别在2008年、2001年、2006年发生突变,突变年份多集中于变暖停滞期,之后的变化趋势显示对全...     

Millennial-scale evolution of Hunshandake Desert and climate change during the Holocene in Inner Mongolia,northern China

The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate.