中国气温变化对全球变暖停滞的响应

1998-2012年出现的全球变暖停滞（global warming hiatus）现象,近年来受到各界的广泛关注。基于中国622个气象站的气温数据,研究了全国及三大自然区气温变化对全球变暖停滞的响应。结果表明：① 1998-2012年间,中国气温变化率为-0.221 ℃/10 a,较1960-1998年增温率下降0.427 ℃/10 a,存在同全球变暖停滞类似的增温减缓现象,且减缓程度更明显,其中冬季对中国增温减缓的贡献最大,贡献率为74.13%,夏季最小;② 中国气温变化对全球变暖停滞的响应存在显著的区域差异,从不同自然区看,1998-2012年东部季风区和西北干旱区降温显著,其中东部季风区为中国最强降温区,为全国增温减缓贡献了53.79%,并且具有显著的季节依赖性,减缓期冬季气温下降了0.896 ℃/10 a,而夏季上升了0.134 ℃/10 a。青藏高寒区1998-2012年增温率达0.204 ℃/10 a,对全球变暖停滞的响应并不显著;③ 中国增温减缓可能受太平洋年代际振荡（PDO）负相位、太阳黑子数与太阳总辐照减小等因素的影响;④ 1998-2012年中国虽出现增温减缓现象,但2012年之后气温快速升高,且从周期变化看,未来几年可能持续升温。     

1960-2015年中国绿洲胡杨生长季对全球变暖的时空响应及原因

基于中国绿洲胡杨（Populus euphratica Oliv.）分布区48个地面气象站1960-2015年逐日平均气温数据,采用线性趋势法、Mann-Kendall检验、ArcGIS反距离加权插值法（IDW）、Morlet小波功率谱和相关分析等方法,分析了中国绿洲胡杨年生长季的起止日及生长期长短对气候变暖的时空响应特征及原因。结果表明：近56年来,中国绿洲胡杨年生长季具有起始日提前、终止日推迟、生长期延长的变化趋势,变化倾向率分别为-1.34 d/10a、1.33 d/10a、2.66 d/10a（α ≥ 0.001）;空间差异十分显著,呈现出由西南向东北起始日越迟,终止日越早,生长期越短的变化规律。胡杨生长季起止日及生长期分别在2001年、1989年和1996年发生突变,且分别存在3.56~7.14 a不等的短周期,与厄尔尼诺2~7 a的周期一致,起始日3.56 a和4.28 a的周期与大气环流2~4 a的周期吻合。原因分析表明亚洲极涡面积指数、青藏高原指数、西风指数和年均二氧化碳排放量是影响胡杨生长季变化的主要因素;此外,纬度对胡杨生长季的影响要明显大于海拔高度,且起始日受纬度和海拔高度的影响比终止日更加显著;胡杨生长季起止日和生长期分别与对应月份的平均气温呈显著的高相关性,且3月均温每升高1 ℃,起始日提前2.21 d,10月均温每升高1 ℃,终止日推迟2.76 d,3-10月均温每升高1 ℃,生长期延长7.78 d,表明胡杨生长季的变化对全球增暖的区域响应十分敏感。     

近44年来中国西北降水量变化的区域差异以及对全球变暖的响应

利用中国西北地区(75~105°E、35~50°N)最近44年(1958~2001年)77个气象台站观测的降水量、气温资料以及NCAR/NCEP再分析资料,采用回归分析与合成分析等方法研究了西北干旱区降水量的时空变化特征及其与全球气温变化的关系。结果表明,西北干旱区的降水量偏多(偏少)与全球平均气温升高(降低)存在一定的对应关系,但降水量随气温的变化存在地域差异,主要表现为干旱区的西部(93°E以西)区域年降水量随全球气温升高呈现增加趋势,而东部(93°E以东)区域年降水量呈减少趋势。     

青藏高原积雪对全球变暖的响应

根据６０个地面基本气象台站１９５７－１９９２年逐日雪深观测记录，用统计模式检验了青藏高原积雪变化趋势，证明近３６年来高原积雪变化呈普遍增加趋势，并且与北球冬季气温呈正相关，高原积雪的增加与北半球温带低地春季积雪面积自８０年代后期的减少形成了鲜明的对比，与两个大陆冰盖雪积累率的增加相一致。     

中国活动积温对气候变暖的响应

活动积温是衡量一个地区农业热量资源的重要指标。未来大气中ＣＯ２等温室气体浓度增加一倍的情景下，全球气候将明显变暖，我国各地的活动积温及持续日数也将有所增加。由于气温增高后积温及其相应的持续日数将同步变化，使此类问题的计算具有一定的难度。本文从积温原理出发，提出一套依据气温变化平均值计算活动积温及其持续日数变化的新方法，并用此方法估算了未来我国各地≥０℃、≥１０℃活动积温及其持续日数的变化。     

中国东北近50年干旱发展及对全球气候变暖的响应

应用实测的降水、气温和土壤湿度资料,分析我国东北区(含黑龙江、吉林、辽宁三省和内蒙古自治区的东部)近50年干旱化的发展趋势.结果表明,用月平均气温和降水量的距平和均方差所构造的"大气干旱指数"以及土壤湿度都显示,近50年来整个东北区是向干旱发展的,1990年代中期以来这种干旱化趋势尤为明显;而东北西部亚干旱地区的干旱化相对更严重(特别是内蒙古东部的北半部).在亚干旱地区的气温和降水两个要素中,气温的升高对干旱化的作用可能更重要.在东北区的南部,近50年来的降水是略有增加,但仍有向干旱发展的趋势.这显然与全球气候变暖的大背景有关.为探讨东北区干旱的发展对全球气候变暖的响应,利用Jones等的1951～2000年全球平均气温资料和东北区25个站的大气干旱指数进行线性回归分析.结果表明,在全球平均温度上升1℃的情况下,中国东北区的干旱化程度要增加5～20%,最大的达到22%.这种形势应该引起我们的关注.     

呼伦贝尔草原对全球变暖的响应

近百年来,尤其近20年,全球气候显著变暖,已导致植物物候与生产力在过去20年中发生显著变化。遥感方法是研究植被对全球变暖的响应的一种非常有效的方式,利用NOAA／AVHRR数据,结合地面气象数据,研究近20年来中国东北地区呼伦贝尔草原NDVI与温度、降水变化的相互关系,认识呼伦贝尔草原对气候变化的响应特征。研究结果表明：(1)呼伦贝尔草原地区近20年温度变化明显,高于全球平均增温幅度。(2)生长季(4～10月)NDVI有较明显上升,线性拟合分析表明,所选4个区域近20年生长季NDVI平均值上升了2．2％。(3)NDVI的增加主要在1988年前后,在草原东部后一阶段(1988～1999)比前一阶段(1982～1987)NDVI平均值增加了7．8％。(4)呼伦贝尔草原对全球变暖响应显著。NDVI与气温,尤其与春季相关性显著。     

近40 a天山北坡气候与生态环境对全球变暖的响应

新疆天山北坡气候变化与生态环境的历史演变过程及未来可能变化趋势是天山北坡经济带可持续发展必须面对的问题,也是正确制定西部大开发战略方针的重要科学基础。通过利用天山北坡18个气象台站在近40a的气温、降水逐年月资料,采用相关分析及线性趋势分析等统计方法,分析了在全球变暖的大背景下,天山北坡生态环境演变特征及其与气候的关系,指出了未来的气候与生态环境变化对天山北坡地区的社会经济发展将产生重要影响。研究表明：天山北坡目前的生态环境正转向好的态势,天山北坡山区和平原普遍存在升温的变化趋势,尤其是平原绿洲升温比较明显。天山北坡在升温的同时,其降水量也呈现上升的趋势。     

全球气候变暖的影响问题辨析

气候变暖对全球各领域及地区可能造成什么样的影响是气候变化相关研究中受关注的一个主题.本研究对全球观测数据和大量过去气候变化研究成果进行分析,针对几个关键问题就全球变暖对人类及其他物种造成不良后果的观点进行了辨析,包括气候模型可能存在的缺陷,冰川、海冰和海平面以及降雨量和水资源变化的不确定性,极端天气事件增强的可能性以及生物的适应能力,指出不宜简单地将所有灾害事件都直接归因于全球变暖,应该在全面科学评估的基础上趋利避害,从而达到更持续发展.     

未来气候变化情景下中国气候生长期演变

利用1971—2010年中国气温数据和区域协同降尺度试验东亚地区项目组RCP 4. 5和RCP 8. 5情景下未来气候预估数据,分析了5℃为界限温度表征的气候生长期演变规律。结果表明:(1) 1971—2010年,全国大部分地区气候生长期略有增加,生长期开始日期提前为主要特征;(2)在RCP 4. 5情景下,气候生长期开始日期的提前主要表现在华东和华中地区以及青藏高原地区,结束日期的推迟表现在青藏高原地区中部、南部和东部以及新疆的“三山地区”,推迟日数均在30 d以上;(3)在RCP 8. 5情景下,气候生长期开始日期受影响范围在RCP 4. 5情景的基础上有所增加,变化日数大幅增加,结束日期则是长江流域以北及青藏高原地区变化日数均较大,长江流域以北和青藏高原地区的气候生长期     

Changes in air temperature over China in response to the recent global warming hiatus

The 1998-2012 global warming hiatus has aroused great public interest over the past several years. Based on the air temperature measurements from 622 meteorological stations in China, the temperature response to the global warming hiatus was analyzed at national and regional scales. We found that air temperature changed -0.221℃/10a during 1998-2012, which was lower than the long-term trend for 1960-1998 by 0.427℃/10a. Therefore, the warming hiatus in China was more pronounced than the global mean. Winter played a dominant role in the nationwide warming hiatus, contributing 74.13%, while summer contributed the least among the four seasons. Furthermore, the warming hiatus was spatial heterogeneous across different climate conditions in China. Comparing the three geographic zones, the monsoon region of eastern China, arid region of northwestern China, and high frigid region of the Tibetan Plateau, there was significant cooling in eastern and northwestern China. In eastern China, which contributed 53.79%, the trend magnitudes were 0.896℃/10a in winter and 0.134℃/10a in summer. In the Tibetan Plateau, air temperature increased by 0.204℃/10a, indicating a lack of a significant warming hiatus. More broadly, the warming hiatus in China may have been associated with the negative phase of PDO and reduction in sunspot numbers and total solar radiation. Finally, although a warming hiatus occurred in China from 1998 to 2012, air temperature rapidly increased after 2012 and will likely to continuously warm in the next few years.     

1960—2019年西北地区气候变化中的Hiatus现象及特征

1998—2012年全球地表平均温度发生变暖停滞（Hiatus）,然而Hiatus现象是否在全球各地均存在尚有争议,其在西北地区的表现及特征缺乏深入研究。本文基于1960—2019年气温地面观测数据,利用累积距平曲线、Mann-Kendall突变检验、滑动t检验及Yamamoto检验进行气候突变分析,结合线性倾向估计进行气候变化趋势分析,对西北地区气候变化中的Hiatus现象及其特征进行了探讨。结果表明：① 西北地区年均气温在1986年、1996年和2012年分别突变,1996年突变升温后在1998—2012年间保持高位震荡;② 1998—2012年间西北地区年均温变化率为-0.20 ℃/10a,呈现明显Hiatus现象,分季节看,冬季降温幅度最大,夏季仍保持升温,春季均温比秋、冬季提前1年开始和结束停滞期,从空间上看,西北地区东南部降温最显著,青藏高原不存在Hiatus;③ 2012年Hiatus结束后西北地区气温普遍快速升高,季节上以冬季升温最快,空间上以南疆升温最快。综合来看,1998—2012年的Hiatus现象在除青藏高原外的西北地区表现明显,停滞后的快速升温值得高度关注。     

1960-2014年中国绿洲严寒期的时空变化特征与成因分析

基于中国绿洲74个地面气象站的逐日平均气温观测资料,计算候平均温度≤ 0 ℃的严寒期起止候及候数,运用线性趋势法、M-K突变检验、Morlet小波分析法、相关分析等方法,分析中国绿洲严寒期的起止候及候数的时空变化特征与成因。结果表明：近55年来,中国绿洲严寒期起始候推后、终止候提前、候数缩短,变化倾向率分别为0.3 p/10a、-0.27 p/10a和-0.58 p/10a;且空间差异显著,其中,柴达木盆地绿洲严寒期来的最早、结束的最晚,严寒期变化趋势最显著。严寒期起止候及候数分别在1990年、1998年、1994年发生突变。严寒期起始候与候数表现出与大气环流和厄尔尼诺有关的显著周期,终止候表现出与太阳活动有关的显著周期,可以证实严寒期起始候和候数的变化与大气环流和厄尔尼诺密切相关,而终止候的变化则与太阳活动有关。青藏高原指数、亚洲区极涡面积指数和二氧化碳排放量是影响研究区严寒期的主要因子,而南亚夏季风指数则对柴达木盆地绿洲影响最显著。研究区严寒期随着经纬度和海拔高度的增加,起始候提前、终止候推后、候数延长,并以纬度的变化最显著。严寒期起止候及候数对区域增暖具有极好的响应,但区域增暖对起止候及候数的影响各不相同。     

Impact of global warming on drought in China

Spatial and temporal change patterns of air temperature (T), precipitation (P), relative humidity (RH), lower vapor pressure (VP), potential evapotranspiration (PET) and drought situation of 690 meteorological stations for all of China were evaluated in this study to understand the effects of warming on regional drought and hydrological processes. Here, the drought extent is expressed by aridity index (AI), which is the ratio of precipitation and reference crop evapotranspiration (ET₀) calculated by FAO Penman-Monteith equation, taking into account air temperature, atmospheric humidity, solar radiation, and wind. Our results indicate that there are different patterns of climate change from 1961 to 2008 and from 1981 to 2008. Little precipitation change occurred in China and ET₀ decreased from 1961 to 2008. But, the warming trend has intensified and the area with significant increasing precipitation has reduced since the early 1980’s and ET₀ has increased in most areas of China from 1981 to 2008 and decreased from 1961 to 2008. The areas affected by drought have shifted from North China and Northeast China to East China and South China since 1981. It is speculated that the increasing warming intensity after 1981 possibly strengthened the power of potential evapotranspiration and resulted in drought in most areas of Northeast China, North China, eastern Southwest China, and especially in East China and South China.     

Causes and effects of spatial and temporal variations of cold period in Chinese oases between 1960 and 2014

Based on daily average temperatures and observation data from 74 meteorological stations in Chinese oases, we calculate five-day (pentad) average temperature ≤0°C for the start and end pentad as well as pentads of cold period using linear regression analysis, nonparametric Mann-Kendall tests, the Morlet wavelet power spectrum, and correlation analysis. We also analyze spatial and temporal variations and their effects on the start and end pentad as well as pentads of cold period in Chinese oases. Results show that over the last 55 years, the start pentad of cold period has been postponed while the end pentad has been advanced. Overall, the pentads have gradually shortened over time at trend rates that are 0.3 p/10a,–0.27 p/10a, and–0.58 p/10a, respectively. Spatial differences are significant, especially for the Qaidam Basin oasis where the start pentad is the earliest, the end pentad is the latest, and the trend of change is most obvious. Mutation points for the start and end pentad as well as pentads of cold period were observed in 1990, 1998, and 1994, respectively. Of these, the start pentad and pentads of cold period show a periodic cycle, related to atmospheric circulation and El Nino events, while the end pentad exhibits a periodic cycle, related to solar activity. The Tibetan Plateau index (TPI), the Asian polar vortex area index (APVAI), and carbon dioxide emissions (CDE) are the main factors affecting cold period in the study area, whereas the South Asian summer monsoon (SASM) index exerts the greatest effect on the Qaidam Basin oasis. The start and end pentad as well as pentads of cold period increase in concert with latitude, longitude, and altitude; in response to these changes, the start pentad is advanced, the end pentad is postponed, and pentads of cold period are gradually extended. Results show that change in latitude is most significant. Overall, the start and end pentad as well as pentads of cold period show clear responses to regional warming, but there are different effects on each.     

The spatiotemporal responses of <Emphasis Type="Italic">Populus euphratica</Emphasis> to global warming in Chinese oases between 1960 and 2015

Daily average temperature data from 48 meteorological stations in Chinese oases that are within the distribution area of Populus euphratica were analyzed to determine the spatiotemporal responses of this tree to climate change. Specifically, the start and end date as well as the number of days that comprised the growing season were analyzed with a multi-year trend line and using the Mann-Kendall mutation test, inverse distance weighted interpolation (IDW) in the software ArcGIS, a Morlet wavelet power spectrum, and correlation analysis. The results of this study show that, over the last 56 years, the start date of the P. euphratica growing season has advanced, while the end date has been postponed, and the number of days that comprise the growing season have gradually increased. The changing trend rates recovered in this analysis for these three time slices are -1.34 d/10 a, 1.33 d/10a, and 2.66 d/10a (α ≥ 0.001), respectively. Data show that while spatial disparity is extremely significant, it is nevertheless the case that along a southwest-to-northeast transect of Chinese oases, the later the start date of the P. euphratica season, the sooner the end data and the shorter the growing season. Mutations points in start and end date, as well as for the growing season overall were observed in 2001, 1989, and 1996, respectively, and the data presented in this paper show that, in particular, the date of this end of this period is most sensitive to climate warming. Growing season cycles for P. euphratica are between 3.56 years and 7.14 years, consistent with the periodicity of El Ni?o events, while a start date cycle between 3.56 years and 4.28 years is consistent with atmospheric circulation cyclicity. The causal analysis presented in this paper shows that the Asian polar vortex area index (APVAI), the Qinghai-Tibet Plateau index (TPI), the westerly circulation index (WCI), and carbon dioxide emissions (CDE) are the main factors influencing spatiotemporal changes in the growth of P. euphratica, the effect of latitude during the growing season is more significant than altitude, and the start date of the growing season is more significantly influenced by these factors than end date. In addition, data show that the start date, end date, and length of the growing season are all significantly correlated with their average corresponding monthly temperature (correlation coefficients are -0.875, 0.770, and 0.897; α≥0.001). Thus, if the average temperature in March increases by 1℃, the start date of the growing season will advance by 2.21 days, while if the average temperature in October increases by the same margin then the seasonal end date will be delayed by 2.76 days. Similarly, if the average temperature between March and October increases by 1℃, the growing season will be extended by 7.78 days. The results of this study corroborate the fact that changes in the P. euphratica growing are sensitive to regional warming and are thus of considerable theoretical significance to our understanding of the responses of Chinese vegetation to climate change as well as to ecological restoration.     

全球升温下中国各地气温变化不同步性研究

利用中国气象中心160站点的实际观测资料,对中国半个世纪的气温变化进行了分析.通过Mann-Kendall突变分析方法和相关分析法,对各个站点的数据进行处理,发现中国各地在全球升温背景下响应时间以及温度变化幅度的不同步现象及其地理分布规律:各地的升温突变点同纬度变化存在一定的关系,大约33°N左右是中国气温突变时间最晚的地带,以此为界,往高纬度和低纬度方向上都趋于提前;但在四季变化上,通过相关分析发现,从东南往西北存在着敏感性增大的趋势.另外,中国各地多年气温变化同经纬度变化有着密切的关系,在气温变化幅度上,存在从西南向东北增大的趋势.     

华北地区气候暖干化的农业适应性对策研究

通过对华北地区1951-2000年的气温和降水的统计资料进行分析,并作出年平均气温距平变化图和平均降水变化图,得出华北地区50多年来气候呈现暖干化趋势,气温明显升高,冬季表现最为明显,降水明显减少,夏季表现最为明显。接着采用降水量减去同时期蒸发力的方法,从水分平衡的角度分析了气候暖干化对地表水资源的影响,得出近50年来,华北地区年及季的水分亏缺量总体呈增加趋势,春季亏缺尤为严重,加剧了对农业生产的不利影响。然后通过大量农业实验数据,分析了气候暖干化对农作物产量、品质、病虫害及化肥农药的使用的影响,得出气候暖干化对农业生产的影响害处远大于利处。在此基础上分析得出华北地区农业应对气候暖干化的主要问题是水问题,然后通过具体实例和对实验数据的分析,提出以下具体建议与适应性对策:积极推广和普及农业节水技术;推广集水保水技术;因水制宜调整农作物类型,发展优势作物;合理调整种植结构,优化作物布局;加强宣传教育,增强农民气候适应意识。