Some Annual Variation Characteristics for the Northern Hemispheric Monthly Mean Precipitation Fields

By the utilization of monthly precipitation data from all stations in the Northern Hemisphere annexed to the 'World Survey of climatology, Vol. 1-15', the distributions of the maximum precipitation months (MPM), the annual relative precipitation (ARP) and the monthly relative precipitation (percent of annual) in January and July are respectively mapped. Moreover the distributions of intermonthly relative precipitation variabilities from January to December are plotted as well. From these figures, the precipitation in the Northern Hemisphere may be classified into three types(continental, oceanic and transitional types) and 17 regions. The precipitation regime may also be divided into two patterns, the global and regional patterns. The global pattern consists of planetary front system and ITCZ and its inter-monthly variation shows the north-and-south shift of the rain belt; the regional pattern consists of the sea-land monsoon and plateau monsoon regime, in which the inter-monthly variation of rain belt shows a east-and-wcst shift.

Asymmetric Mean Annual Temperature Wavelets Surface Air Layer of Berlin for 1701-2021

The regularities of the dynamics of the average annual temperature of Ber­lin from 1701 to 2021 are revealed.A total of 65 wavelets were received.The temperature has a high quantum certainty,and the change in the aver­age annual temperature of Berlin was identified by a model that contains only two components for prediction.The basis of the forecast at 320 years makes it possible to look into the future until the year 2340.The forecast confirms the conclusions made in the CMIP5 report on global warming.With an increase in the number of components in the model up to five,the forecast is possible only until 2060.Therefore,the model with only two components is workable.The trend is characterized by a modified Man­delbrot equation showing exponential growth with a high growth rate of 1.47421.The wave equation also has an amplitude in the form of the Man­delbrot law(in mathematics,the Laplace law,in biology,the Zipf-Pearl law,in econometrics,the Pareto law),when the exponential growth activity is equal to 1.For 1701,the period of oscillation was 2×60.33333≈120.7 years.By 2021,the period decreased and became equal to 87.6 years.The trend is such that by 2340 the period of oscillation will decrease to 30.2 years.Such an increase in fluctuations indicates an imbalance in climate disturbances in temperature in Berlin.For Berlin,the last three years are characterized by sharp decreases in the average annual temperature from 11.8℃ to 10.5℃,i.e.by 12.4% in 2021.Therefore,the forecast is still unstable,as a further decrease in the average annual temperature of Berlin in the near future may change the picture of the forecast.

VARIATION OF MEAN ANNUAL PRECIPITATION IN THE RECENT HUNDRED YEARS IN EAST CHINA

Precipitation and temperature are the two most important indicators of the climatic variation. Many studies have been done on the variation of large scale mean temperature. However, it is difficult to build a long-term time series of global or hemispheric mean precipitation. In this note, we attempt to make the time series of the mean annual rainfall over east China in the recent hundred years to have a view of historical fluctuation of large scale drought and flood in quantities.

Temporal and spatial variation of annual mean air temperature in arid and semiarid region in northwest China over a recent 46 year period

We analyzed the 1961-2006 mean surface air temperature data of 138 stations in China’s northwest arid and semi-arid areas(CNASA),to measure climate change in terms of annual mean air temperature changes.We used methods of linear regression analysis,multinomial fitting,Empirical Or-thogonal Function(EOF),Rotated Empirical Orthogonal Function(REOF),Mann-Kendall,Glide T-examination,wavelet analysis and power spectrum analysis.The results show that(1) the warming rate of the annual mean air temperature in CNASA was 0.35oC/10a during the 1961-2006 study period.Some places in the west part of Xinjiang and east part of the Qinghai plateau,which is impacted by the terrain of leeward slope,exhibit smaller increasing trends.However,the majority of region has shown distinct warming in line with general global warming;(2) The standard deviation of the annual mean temperature distribution is non-uniform.The south Xinjiang and east Qinghai-south Gansu areas show relatively small standard deviations,but the inter-annual variation in annual mean air temperature in the greater part of the region is high;(3) Inner Mongolia,Shaanxi,Gansu,Ningxia and Tarim Basin are the areas where the temperature changes are most sensitive to the environment.The degree of uniformity in annual mean air temperature increase is higher in the arid and semi-arid area.From the early 1970s,the trend in tempera-ture changed from a decrease to an increase,and there was a marked increase in mean temperature in 1986.After that mean temperature went through a period of rapid increase.The entire area’s 10 hottest years all occurred in or since the 1990s,and 90% of various sub-districts’ hottest years also occurred after 1990.The process of temperature change appears to have a roughly 5-year and a 10-year cycle;(4) An-nual mean air temperature variation has regional differences.In Inner Mongolia-Xinjiang and Shaanxi-Gansu-Ningxia-Qinghai areas,the temperature variation in their northern areas was very different from that in their southern areas;(5) Using the REOF method we divided the region into 4 sub-regions:the Northern region,the Plateau region,the Southern Xinjiang region and the Eastern region.The region’s annual mean air temperature transition has regional differences.The Plateau and Southern Xinjiang re-gions got warmer steadily without any obvious acceleration in the rate of warming.The Northern region’s warming started about 5-years earlier than that of the low latitude Eastern region.The ’Startup region’ of the Qinghai-Tibet Plateau,appears to undergo temperature changes 3 to 10 years earlier than the other regions,and exhibits inter-decadal variations 1 to 2 years ahead of the other regions.

Global Annual Mean Surface Air Temperature Anomalies and Their Link with Indian Summer Monsoon Failures

Analysis of the global mean annual temperature anomalies based on land and marine data for the last 88 years (1901-1988) of this century has been carried out with a view to find any relationship with failures in Indian summer monsoon rainfall. On the climatological scale (i.e. 30 years) it has been noticed that there is an abnormal increase in the frequency of drought years during epochs of global warming and cooling, while it is considerably less when global temperatures are near normal. Results are unchanged even when the data are filtered out for ENSO (El-Nino Southern Oscillation) effect.It has also been noticed that during warm and cold epochs in global temperatures the amount of summer monsoon rainfall decreases as compared to the rainfall during a normal temperature epoch.

Spatial and temporal relationships between precipitation and ANPP of four types of grasslands in northern China

Precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 48 sites （including temperate meadow steppe, temperate steppe, temperate desert steppe and alpine meadow） were gathered from 31 published papers and monographs to analyze the relationship between above-ground net primary productivity （ANPP） and precipitation by the method of regression analysis. The results indicated that there was a great difference between spatial pattern and temporal pattern by which precipitation influenced grassland ANPP. Mean annual precipitation （MAP） was the main factor determining spatial distribution of grassland ANPP （r^2 = 0.61, P 〈 0.01）; while temporally, no significant relationship was found between the variance of AN PP and inter-annual precipitation for the four types of grassland. However, after dividing annual preeipitation into monthly value and taking time lag effect into account, the study found significant relationships between ANPP and precipitation. For the temperate meadow steppe, the key variable determining inter-annual change of ANPP was last August-May precipitation （r^2 = 0.47, P = 0.01）; for the temperate steppe, the key variable was July precipitation （r^2 = 0.36, P = 0.02）; for the temperate desert steppe, the key variable was April-June precipitation （r^2 = 0.51, P 〈 0.01）; for the alpine meadow, the key variable was last September-May precipitation （r^2 = 0.29, P 〈 0.05）. In comparison with analogous research, the study demonstrated that the key factor determining inter-annual changes of grassland ANPP was the cumulative precipitation in certain periods of that year or the previous year.

一种基于三维指标因子的流域多年径流丰枯k-means聚类法

径流丰枯聚类研究的传统方法多建立在年径流量的单一指标之上,容易导致分析的片面化。针对这个问题,提出了衡量流域多年径流丰枯状态的三维指标因子及权重,将其耦合到k-means聚类法的相似度计算与收敛分析中,在此基础上对对多年径流进行丰枯聚类,构建了一种基于三维指标因子的流域多年径流丰枯k-means聚类法。以该方法对广东省鉴江流域下游化州站1956—2006年的径流系列进行聚类分析,并与基于年径流量单一指标的k-means聚类方法进行对比,结果表明该方法是较全面且符合实际的。

Are There Differences in the Response of Natural Stand and Plantation Biomass to Changes in Temperature and Precipitation?A Case for Two-needled Pines in Eurasia

A comparative discussion of the advantages and disadvantages of natural stands and plantations,including in terms of their productivity and stability,began from the moment of the first forest plantings and continues to this day.In the context of the progressive replacement of natural forests by plantations due to deforestation,the question of how will change the carbon storage capacity of forest cover when replacing natural forests with artificial ones in a changing climate becomes extremely relevant.This article presents the first attempt to answer this question at the transcontinental level on a special case for two-needled pine trees(subgenus Pinus L.).The research was carried out using the database compiled by the authors on the single-tree biomass structure of forest-forming species of Eurasia,in particular,data of 1880 and 1967 of natural and plantation trees,respectively.Multi-factor regression models are calculated after combining the matrix of initial data on the structure of tree biomass with the mean January temperature and mean annual precipitation,and their adequacy indices allow us to consider them reproducible.It is found that the aboveground and stem biomass of equal-sized and equal-aged natural and plantation trees increases as the January temperature and precipitation rise.This pattern is only partially valid for the branches biomass,and it has a specific character for the foliage one.The biomass of all components of plantation trees is higher than that of natural trees,but the percent of this excess varies among different components and depends on the level of January temperatures,but does not depend at all on the level of annual precipitation.A number of uncertainties that arose during the modeling process,as well as the preliminary nature of the obtained regularities,are noted.

高温不稳定多年冻土区保温护道路基热状况监测分析

基于高温不稳定多年冻土区保温护道路段地温监测数据,分析了天然场地及左右路肩下地温、年平均地层温度、热收支及多年冻土上限变化等,探讨了气候变暖及阴阳坡效应下路基不同位置不同深度热状态变化特性及其与天然场地的差异。结果表明:左右路肩阴阳坡效应显著,左路肩下多年冻土最大融化深度为右路肩的2倍,最大融化深度降低速率为右路肩的5倍,且左路肩下多年冻土上限下降速率为右路肩的1.5倍;右路肩处在阴坡且保温护道可能对其多年冻土维持稳定起到了一定积极作用,抬升了其人为冻土上限并减缓了上限下降速率。不同位置年平均地层温度均呈上升趋势,且增长速率随深度逐渐降低,然而左路肩的路基与天然场地交界面附近温度增长速率大于2.5 m深度处,表明此特殊位置土层在多因素作用下可能受到更强的热扰动影响。一般情况下,冻土吸热放热量均随深度降低逐渐减少,但多年冻土上限处在0℃等温线的特殊位置,可能出现吸热量突然增大的现象;多年冻土上限处由于深度较深,热收支增长速率已不受阴阳坡效应影响,该断面左路肩多年冻土上限处年平均热收支为右路肩的2.92倍,但其热收支增长速率几乎相等。

ESTIMATES OF CLIMATE NOISES OF ANNUAL MEAN TEMPERATURES OVER CHINA

In this paper,a design to estimate climate noise of annual mean temperature has been made by means of the mini- mum interannual variance and effectively independent observations in time series.By using it the climate noises of annu- al mean surface air temperatures have been estimated based on the data from 1960 to 1991 in this country.The low val- ues of climate noises of annual mean temperatures are found in the southeastern Tibet Plateau,Yunnan,the Sichuan Ba- sin and south of the middle and lower reaches of the Changjiang River Valley.The high values are seen in the northwestern and northeastern China and the rest of the Tibet Plateau.A relatively low value region is in the southern Xinjiang.

阿勒泰林区不同草地群落特征对水热因子的响应

[目的]探讨阿勒泰林区不同草地群落植物物种丰富度(SR)对年平均温度(MAT)、降水(MAP)、海拔的响应,为该区退化草地恢复与管理提供科学依据。[方法]选取阿勒泰林区600~3914 m范围内的5种草地类型作为研究对象,采用样方法对165个样方的物种名录进行了调查,分析了各类草地植物科属种的变化特征。[结果](1)在新疆阿勒泰林区草地中,菊科、禾本科和豆科为优势科,其中碱茅属、蒲公英属、羽衣草属和发草属表现为优势属;(2)物种丰富度(SR)在不同草地变化有所不同,山地草甸草原物种丰富度最高(8.86),而高寒草甸(4.75)最低。(3)全部样地SR与MAP,MAT和海拔呈线性关系;在荒漠草原的SR与MAP和MAT的关系表现为先增加后降低的趋势,同时与海拔呈现先降低再增加的变化趋势。在山地草原中,其SR与MAP,MAT无明显相关性,与海拔的关系呈峰型分布。山地草甸草原的SR与MAP、海拔无明显相关性,与MAT的关系呈峰型分布。山地草甸的SR与MAP、海拔无相关性,与MAT呈峰型关系;高寒草甸的SR与MAP、海拔均呈先降低后增加的趋势,与MAT呈峰型关系。[结论]不同草地类型对温度、降水响应的差异是由于植被类型和温度、降水的空间分异性造成的;而不同海拔梯度水热条件不同,导致物种丰富度之间存在一定差异。

Surface Air Temperature Simulations over China with CMIP5 and CMIP3

Historical simulations of annual mean surface air temperature over China with 25 CMIP5 models were assessed.The observational data from CRUT3v and CN05 were used and further compared with historical simulations of CMIP3.The results show that CMIP5 models were able to simulate the observed warming over China from 1906 to 2005(0.84 C per 100 years)with a warming rate of 0.77 C per 100 years based on the multi-model ensemble(MME).The simulations of surface air temperature in the late 20th century were much better than those in the early 20th century,when only two models could reproduce the extreme warming in the 1940s.The simulations for the spatial distribution of the 20-yearmean(1986–2005)surface air temperature over China fit relatively well with the observations.However,underestimations in surface air temperature climatology were still found almost all over China,and the largest cold bias and simulation uncertainty were found in western China.On sub-regional scale,northern China experienced stronger warming than southern China during 1961–1999,for which the CMIP5 MME provided better simulations.With CMIP5 the diference of warming trends in northern and southern China was underestimated.In general,the CMIP5 simulations are obviously improved in comparison with the CMIP3 simulations in terms of the variation in regional mean surface air temperature,the spatial distribution of surface air temperature climatology and the linear trends in surface air temperature all over China.

Variability of Wintertime Surface Air Temperature over the Kingdom of Saudi Arabia

Variability of wintertime surface air temperature (SAT) in the Kingdom of Saudi Arabia (KSA) is studied. The study is based on time series over thirty one years in length (1978-2008). For the analysis, we use the coefficient of variability (COV) Mann-Kendal statistical test, running mean and cumulative annual mean (CAM). The coefficient of variability (COV) for wintertime SAT decreases gradually from the north to the south of KSA. The higher values for COV occur in northern and northeastern KSA;there are due to the effect of the traveling Mediterranean depressions and their interaction with the inverted-V shape trough of the Sudan low. The relationship between COV and latitude is highly significant, while with longitude it is not significant. The Mann-Kendal statistical test illustrates that positive trends (warming) in wintertime SAT series occurs over the all stations, and that the trends are significant at middle and southern regions of KSA. Recent warming has only occurred during the last two decades at most stations. While cooling in the wintertime SAT appears for the short period of about 5 years, 1978-1983 and 1988-1992. These trends are consistence with trends in the global mean SAT. The results obtained from CAW lead to the conclusion that the thermic regime is modifying in the KSA. This dramatic enhancement, occurred at the beginning of the year 1993, is reflected in net modification in the SAT time series. The analysis of the SAT also shows a significant warming trend after the year 1997 with a rate of 0.03?C/year.

青藏高原不同类型高寒草地物种多样性与生物量的关系及影响要素

本研究以青藏高原为研究区,基于实测的115个样点调查数据,包括群落结构、土壤因素以及气候指标,利用单因素方差和线性回归分析,结合结构方程模型探究了不同类型高寒草地(高寒草甸和高寒草原)地上生物量和物种多样性的差异及其关系,并试图厘清不同草地类型生物多样性与地上生物量的主要驱动要素。结果表明:1)地上生物量与物种多样性在高寒草甸与高寒草原之间均存在显著差异(P<0.05),且二者关系在两种草地类型均呈显著正相关关系(P<0.05)。2)驱动因子分析表明,年均降水量(AMP)与地上生物量(AGB)和物种多样性存在显著正相关关系(P<0.05);高寒草甸中土壤有机碳(SOC)、土壤速效氮(SAN)和土壤速效磷(SAP)含量与地上生物量呈显著正相关关系(P<0.01),而物种多样性(Shannon-Wiener指数)仅与土壤含水量(SWC)呈显著正相关关系(P<0.05);高寒草原的SOC、SAN含量与地上生物量和物种多样性呈显著正相关关系(P<0.01),且SWC、SAP含量与地上生物量和物种多样性之间的相互关系均不显著(P>0.05)。3)结构方程模型分析指示年均降水量分别解释了高寒草甸和高寒草原55.8%和60.3%的物种多样性变异,且物种多样性与地上生物量关系密切,对高寒草甸和高寒草原的地上生物量影响分别为51.3%和30.2%,同时土壤养分也进一步制约着高寒草地的生物量。综上可知,水分主导了高寒草地物种多样性和地上生物量的空间格局和关键生态过程,该研究结果可为未来高寒草地应对青藏高原暖湿化气候趋势提供基础数据和理论参考。

Influence of Climate on Soil Organic Carbon in Chinese Paddy Soils

Soil organic carbon(SOC) is a major component of the global carbon cycle and has a potentially large impact on the greenhouse effect. Paddy soils are important agricultural soils worldwide, especially in Asia. Thus, a better understanding of the relationship between SOC of paddy soils and climate variables is crucial to a robust understanding of the potential effect of climate change on the global carbon cycle. A soil profile data set(n = 1490) from the Second National Soil Survey of China conducted from 1979 to 1994 was used to explore the relationships of SOC density with mean annual temperature(MAT) and mean annual precipitation(MAP) in six soil regions and eight paddy soil subgroups. Results showed that SOC density of paddy soils was negatively correlated with MAT and positively correlated with MAP(P < 0.01). The relationships of SOC density with MAT and MAP were weak and varied among the six soil regions and eight paddy soil subgroups. A preliminary assessment of the response of SOC in Chinese paddy soils to climate indicated that climate could lead to a 13% SOC loss from paddy soils. Compared to other soil regions, paddy soils in Northern China will potentially more sensitive to climate change over the next several decades. Paddy soils in Middle and Lower Yangtze River Basin could be a potential carbon sink. Reducing the climate impact on paddy soil SOC will mitigate the positive feedback loop between SOC release and global climate change.

兴安落叶松(Larix gmelinii Rupr.)叶片养分的空间分布格局

对中国东北温带森林生态系统主要树种兴安落叶松(Larix gmelinii Rupr.)24个采样点72个叶片样品有机碳(C)、全氮(N)、全磷(P)和全钾(K)的化学组成、地理分布格局及其与气候因子的关系进行了研究。结果表明,叶片C、N、P和K含量的几何平均数分别为543.970、16.902、2.373mg/g和14.625mg/g,且叶片的C含量>N含量>K含量>P含量;叶片的C/N、C/P和N/P分别为32.183、229.226和7.123。随纬度的增加、年均温度和年均降雨量的降低,兴安落叶松叶片C、N含量和N/P显著降低,叶片C/N和K含量显著升高,叶片P含量和C/P的变化没有达到显著水平。叶片N含量随纬度与年均温度的变化与全球及其它大尺度的研究结果相反,而N/P与其一致,这与在该区域的其它物种的研究结果基本一致。这可能是由于在本研究区域北部寒温带越往高纬度地区年均温度和年均降雨量越低、生长季越短,因此成土作用弱导致植物可以吸收利用的养分越少,但是由于植物显著降低的N含量和变化不明显的P含量导致了叶片N/P随纬度的增加和年均温度和年均降雨量的降低而降低,这与全球尺度的研究结果一致。兴安落叶松叶片养分分布格局与全球尺度和中国区域研究结果的差异说明了加强区域叶片养分特征研究的重要性。叶片养分与气候因子的显著线性相关说明气候因子是影响叶片养分特征的一个主要因子。

新疆塔里木河流域近50a气候变化及其对径流的影响

根据塔里木河源流区1958-2004年的水文气象数据,利用Mann-Whitney和Mann-Kendall非参数技术检验,对塔里木河源流区近50 a来气候变化的长期趋势、变化特征及其空间分布进行检测,并分析了塔里木河流域气候变化背景下的径流变化趋势.结果表明:流域气温和降水均在20世纪80年代中期发生了跳跃式的突变,且自20世纪80年代中期以来气温和降水均保持较高的增长趋势,90年代成为近半个世纪以来最温暖的10 a.阿克苏河区和开孔河区增温幅度大于叶尔羌河区和和田河区,除和田河区外,各区的增湿幅度基本上都超过了10%.与气候变化相一致,塔里木河上游源流区的年径流量除和田河表现出轻微减少趋势外,叶尔羌河和阿克苏河的年径流量均呈增加趋势,其中,阿克苏河的年径流量增加了10.9%.流域气温、降水与厄尔尼诺的χ2独立性检验表明,El Nio与La Nia事件对流域年均气温和年降水不存在显著的影响.

中国杉木林生物量估算参数及其影响因素

收集整理杉木林的生物量文献数据,探讨3个常用的生物量估算参数(生物量换算系数BCEF、生物量扩展系数BEF和根茎比R)及其影响因素。结果表明:BCEF,BEF和R的平均值分别为0.616 Mg·m-3(n=245,SD=0.426)、1.489(n=334,SD=0.379)和0.247(n=268,SD=0.083);随着林龄、平均胸径、平均树高和立木蓄积量增加,BCEF,BEF和R值逐渐减小并趋于稳定(P<0.001),但随着林分密度增加,它们呈现显著增加的趋势(P<0.001);随着年均气温增加,BEF和R逐渐减小(P<0.05),但BCEF无明显的变化趋势;随着年均降水量增加,BEF逐渐减小,当降水量大于1 550 mm后,其又逐渐增加(P<0.001),而BCEF和R均无明显的变化趋势。因此,在应用BEF和R估算较大环境梯度的森林生物量时,应综合考虑林分特征指标和气候因素的影响,尤其是BEF。

河北省年均降水量插值方法比较

以河北省及临近区域120个气象观测站点1971～2000年均降水量数据为基础,选择其中的40个作为检验站点,其余站点分别取80、40、20个作为插值站点,采用局部插值、整体插值、多元线性回归、综合模拟等多种插值模型讨论了降水空间插值问题,主要结论如下:插值站点数、模型类型、模型参数都会影响插值精度。局部插值模型相对误差最小值出现在Spline、IDW模型中,其次为Kridging模型,而整体模型Trend、多元线性回归模型误差均较大,但综合了局部插值模型和统计模型的综合模型一定程度上能改善插值精度及误差分布。河北省80和40个站点的最优插值模型为综合模型,20个站点的最优插值模型为IDW2。

岷江上游黑水河流域不同景观结构小流域径流系数的比较

在GIS技术支持下,结合岷江上游黑水河流域1988—2002年多年平均降水量和蒸散量空间分布,对不同景观结构的小流域多年平均径流系数进行比较。结果表明:不同土地覆盖类型组合流域多年平均径流系数大小关系依次为林灌流域<林灌草复合流域<森林流域<林草流域,这与流域土地利用类型、流域海拔分布和迎风坡向分布特征有关;对于森林流域和灌木流域,其多年平均径流系数主要受多年平均降水量、多年平均蒸散量和平均坡度共同影响;对于林草流域和林灌草复合流域,其多年平均径流系数主要受流域的多年平均降水量、多年平均蒸散量和多林草面积比共同影响。