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构建描述两种ENSO类型的新指数 被引量:17
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作者 秦坚肇 王亚非 《气象学报》 CAS CSCD 北大核心 2014年第3期526-541,共16页
利用英国气象局哈得来中心的1950—2011年月平均海表温度资料,采用联合回归-经验正交函数分解方法得到东部太平洋型ENSO(东部型ENSO)和中部太平洋型ENSO0中部型ENSO)的热带太平洋海温分布特点,进而定义了计算相对简单的东部型ENSO指数(I... 利用英国气象局哈得来中心的1950—2011年月平均海表温度资料,采用联合回归-经验正交函数分解方法得到东部太平洋型ENSO(东部型ENSO)和中部太平洋型ENSO0中部型ENSO)的热带太平洋海温分布特点,进而定义了计算相对简单的东部型ENSO指数(I_(EP))和中部型ENSO指数(I_(CP))来分别描述两类ENSO。研究结果表明:首先,构建的I_(EP)和I_(CP)的相关性很小,接近正交,而且I_(EP)和I_(CP)能够反映两类ENSO不一致的偏度和周期,因此,这对指数能够清楚地区分两类ENSO。其次,I_(EP)和I_(CP)这两个指数可以描述厄尔尼诺和拉尼娜事件成熟期主要海表温度异常区的位置。再次,应用I_(EP)和I_(CP)从随机事件概率统计的角度给出两类厄尔尼诺和拉尼娜事件较为严格的定义,以便实时有效地监测两类ENSO。最后,利用新指数对两类ENSO的特征进行研究发现,强厄尔尼诺事件一般属于东部型,而强拉尼娜事件则为中部型,并且中部型拉尼娜事件发生的前期是东部型厄尔尼诺,此外,ENSO的发生演变机制在1976/1977年前后发生了改变。 展开更多
关键词 东部型ENSO 中部型ENSO 海表温度异常 气候态转变
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Recent greening of grasslands in northern China driven by increasing precipitation 被引量:2
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作者 Kai Di Zhongmin Hu +6 位作者 Mei Wang Ruochen Cao Minqi Liang Genan Wu Ruru Chen Guangcun Hao Yaolong Zhao 《Journal of Plant Ecology》 SCIE CSCD 2021年第5期843-853,共11页
Aims Recent warmer and wetter climate in northern China remains a hot topic in recent years,yet its effect on vegetation growth has not been fully understood.This study investigated the temporal change of vegetation c... Aims Recent warmer and wetter climate in northern China remains a hot topic in recent years,yet its effect on vegetation growth has not been fully understood.This study investigated the temporal change of vegetation cover and its correlations with climatic variables from 1982 to 2018 for grasslands in northern China.Our aim is to clarify whether the warmer and wetter climate in recent years drives the greening of the vegetation in this region.Methods We investigated the temporal dynamic of vegetation normalized difference vegetation index(NDVI)and its driving forces based on long time-series data.Piecewise regression was used to examine whether there was a turning point of the trend of NDVI and climatic variables.Pearson correlation analyses were conducted to quantify the relationship between NDVI and climatic factors.Stepwise multivariable regression was used to quantify the contributions of climate variables to the temporal variations in NDVI.Important Findings We found a turning point of NDVI trend in 2008,with GIMMS NDVI indicating a slight increase of 0.00022 yr?1 during 1982–2008 to an increase of 0.002 yr?1 for GIMMS NDVI during 2008–2015 and 0.0018 yr?1 for MODIS NDVI during 2008–2018.Precipitation was the predominant driver,and air temperature and vapor pressure deficit exerted a minor impact on the temporal dynamics of NDVI.Overall,our results suggest a turning point of NDVI trend,and that recent warmer and wetter climate has caused vegetation greening,which provides insights for better predicting the vegetation cover in this region under changing climate. 展开更多
关键词 plant growth temporal dynamics turning point trend change climate change
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The Ecosystem Condition of Basin of the Trans Border River Argun in Zabaikalsky Krai, Russia 被引量:3
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作者 Gazhit Ts. TSYBEKMITOVA 《Journal of Resources and Ecology》 CSCD 2015年第2期119-122,共4页
Cyclic climatic changes, as well as the press of anthropogenic impact, affect ecosystems of the river Argun basin. Specialization of basin management is industrial and agricultural. The main impact is connected with t... Cyclic climatic changes, as well as the press of anthropogenic impact, affect ecosystems of the river Argun basin. Specialization of basin management is industrial and agricultural. The main impact is connected with the development of mining companies (including the mining of ore and placer gold), energy facilities, and the formation of reservoirs in the basin of rivers: the Argun -- the Hailar. As a result of natural and anthropogenic pressure, the limiting factor for ecosystem exploitation in this basin is water resources (water deficiency and its quality). 展开更多
关键词 river basin legal and regulatory framework transformation of the ecosystems climate anthropogeniccontributions HYDROCHEMISTRY biodiversity
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