西北地区气候资源综合利用学术研讨会在银川召开

1991年9月11日至13日在宁夏回族自治区银川市召开了“西北地区气候资源综合利用学术研讨会”。参加会议的有西北五省区气象部门代表、兰州区域气象中心协调办公室的代表以及宁夏计委、农业厅、农业经济研究所等单位代表共22人。其中14人在大会上作报告,内容有光能资源、水资源分布及合理利用;光能资源、太阳辐射的气候学计算;西北地区旱涝演变规律及其预测;客观降水分析及农业气象和漆树生态气候研究。

西北气候"真的"正在变暖变湿吗

21世纪初,中国科学院寒区旱区环境与工程研究所施雅风院士等专家,提出了西北地区气候从“暖干”向“暖湿”转型的判断,认为这是一个将持续数十年的年代际变法.如今,西北地区的人感到,寒冷干旱的西北变得有点像南方了,不仅变暖,而且雨水变多,干涸多年的湖泊再漾碧波,荒山秃岭逐渐显现绿色。

青藏铁路灾害演变趋势的初步展望

近百年来,由于人类活动引起的温室效应,正在越来越大地、不可逆转地影响着全球的气候变化,并终将超过气候的自然变化,成为未来气候变化的主要趋势。因此,这一问题已经引起国际社会的普遍关注。研究表明,到2030年左右,全球的年平均气温将比现在升高1.5～4.5℃,冬季我国约增温4℃,夏季约增温2℃,亚热带的北界将由今天的秦岭淮河一线扩展到黄河以北。

新生犊牛成活率低的原因分析及应对措施

新生犊牛能否吃上初乳是新生犊牛能否成活的重要环节,也很大程度影响着养殖场户经济收益。为了提高犊牛吃乳能力从而提高成活率,本文分析原因、总结经验,以期为养殖场户提供养殖参考。随着秦川牛的改良以及纯种西门塔尔牛的引进,传统农户的散养向规模化养殖过渡,再加上西北地区气候多变的影响,新生犊牛吃乳困难成为迫切需要解决的重要问题。

《干旱气象》2010—2020年高被引文章前10

王劲松,李耀辉,王润元,冯建英,赵艳霞.我国气象干旱研究进展评述,2012(3),被引:233张强,张存杰,白虎志,李林,孙兰东,刘德祥,王劲松,赵红岩.西北地区气候变化新动态及对干旱环境的影响——总体暖干化,局部出现暖湿迹象,2010(1),被引:212.

Characteristics of Extreme Temperature Event and Its Response to Regional Warming in Northwest China in Past 45 Years

Using the daily maximum and minimum temperature dataset from 128 stations from 1960 to 2004 in Northwest China,daily extreme high temperature(EHT)and extreme low temperature(ELT)thresholds were deter-mined by centesimal method for different stations at first,then yearly EHT and ELT events were counted up in differ-ent stations,and the characteristics of their spatio-temporal distribution were diagnosed at last.The study drew follow-ing conclusions:1)The consistent anomaly distribution characteristic was the most important mode of the EHT and ELT events in Northwest China.2)The spatial distribution of the EHT and ELT events can be divided into five sub-regions,namely,the north of Qinghai and west of Gansu,the north of Xinjiang,the south of Xinjiang,the east of Northwest China and the south of Qinghai.3)The EHT events showed remarkable increasing trend in all of five sub-regions,but only in the north of Qinghai and west of Gansu area,sudden change phenomenon occurred;the ELT events showed decreasing trend in all of five sub-regions,and sudden change phenomenon occurred in Northwest China except for south of Qinghai.4)In all of five sub-regions the EHT events showed remarkable 12-14yr period os-cillation,and the ELT event showed significant 13-15yr and 7-8yr period oscillation.5)The EHT and ELT events displayed remarkable positive and negative responses to regional warming of Northwest China respectively.

Features of Climate Change in Northwest China during 1961-2010

In this study, observational data from 141 meteorological stations in Northwest China, including temperature, precipitation, dust storm, gale days and wind speed, were analyzed statistically to gain insight of the features of basic climate index and extreme climate events. The results showed that the annual mean temperature and seasonal mean temperature rose significantly, and the rising rate of the annual mean temperature is 0.27℃ per decade; the extreme high temperature days have increased; the interdecadal change of annual precipitation is marked, and the precipitation in winter and summer increased slightly, while decreased slightly in spring and autumn. The annual precipitation increased in the area west of the Yellow River, whereas decreased in the area east of the river. The drought had an increasing trend. There were 17 droughts during 1961-2010, and 10 droughts from 1991 to 2010. The number of droughts in spring and autumn increased, while decreased in summer.

Projected Climate Change in the Northwestern Arid Regions of China: An Ensemble of Regional Climate Model Simulations

The projected temperature and precipitation- change under different emissions scenarios using Coupled Model Intercomparison Project Phase 5 models over the northwestern arid regions of China （NWAC） were ana- lyzed using the ensemble of three high-resolution dy- namical downscaling simulations： the simulation of the Regional Climate Model version 4.0 （RegCM4） forced by the Beijing Climate Center Climate System Model version 1.1 （BCC_CSMI.1）; the Hadley Centre Global En- vironmental Model version 3 regional climate model （HadGEM3-RA） forced by the Atmosphere-Ocean cou- pled HadGEM version 2 （HadGEM2-AO）; and the Weather Research and Forecasting （WRF） model forced by the Norwegian community Earth System Model （NorESM1-M）. Model validation indicated that the mul- timodel simulations reproduce the spatial and temporal distribution of temperature and precipitation well. The temperature is projected to increase over NWAC under both the 4.5 and 8.5 Representative Concentration Path- ways scenarios （RCP4.5 and RCP8.5, respectively） in the middle of the 21 st century, but the warming trend is larger under the RCP8.5 scenario, Precipitation shows a signifi- cant increasing trend in spring and winter under both RCP4.5 and RCPS.5; but in summer, precipitation is pro- jected to decrease in the Tarim Basin and Junggar Basin. The regional averaged temperature and precipitation show increasing trends in the future over NWAC; meanwhile, the large variability of the winter mean temperature and precipitation may induce more extreme cold events and intense snowfall events in these regions in the future.

Individual Variations of Winter Surface Air Temperature over Northwest and Northeast China and Their Respective Preceding Factors

Based on monthly mean surface air temperature （SAT） from 71 stations in northern China and NCEP/ NCAR and NOAA-CIRES （Cooperative Institute for Research in Environmental Sciences） twentieth century reanalysis data, the dominant modes of winter SAT over northem China were explored. The results showed that there are two modes that account for a majority of the total variance over northern China. The first mode is unanimously colder （warmer） over the whole of northern China. The second mode is characterized by a dipole structure that is colder （warmer） over Northwest China （NWC） and warmer （colder） over Northeast China （NEC）, accounting for a fairly large proportion of the total variance. The two components constituting the second mode, the individual variations of winter SAT over NWC and NEC and their respective preceding factors, were further investigated. It was found that the autumn SAT anomalies are closely linked to persistent snow cover anomalies over Eurasia, showing the delayed effects on winter climate over northern China. Specifically, the previous autumn SAT anomalies over the Lake Baikal （LB; 50-60°N, 85-120°E） and Mongolian Plateau （MP; 42-52°N, 80-120°E） regions play an important role in adjusting the variations of winter SAT over NWC and NEC, respectively. The previous autumn SAT anomaly over the MP region may exert an influence on the winter SAT over NEC through modulating the strength and location of the East Asian major trough. The previous autumn SAT over the LB region may modulate winter westerlies at the middle and high latitudes of Asia and accordingly affects the invasion of cold air and associated winter SAT over NWC.

Abrupt Climate Changes of Holocene

This paper is a review of studies of abrupt climate changes(ACCs) during the Holocene published during the past ten years.North Atlantic cold events are indicators of ACCs.As indicated by North Atlantic ice-rafted debris(IRD),there were nine confirmed cold events during the Holocene,occurring at 11.1 kyr,10.3 kyr,9.4 kyr,8.1 kyr,5.9 kyr,4.2 kyr,2.8 kyr,1.4 kyr,and 0.4 kyr respectively according to most representative results from Bond et al.(1997).However,the identification of chronology has been made with some uncertainties.Considerable climatic proxy data have shown that,during the cold events,substantial climate abnormalities have occurred widely across the globe,particularly in the areas surrounding the North Atlantic.These abnormalities were in the form of high-latitude cold in the both hemispheres,expansion of the Westerlies to low latitudes,drought in the monsoon regions,recession of summer monsoons,and intensification of the winter monsoons.Studies have indicated that the four ACCs occurring in the early Holocene may be related to freshwater pulses from ice melting in the northern part of the North Atlantic,and the other five ACCs that occurred during the middle and late Holocene may be related to the decreased solar activity.

Index System and Influence of Drought in Northwest China

In this paper, the index systems of the agricultural drought and decrease percentage of grain crop are established. The trend and influence of drought in the region is analyzed based on the 50 years （1951-2000） statistical data of precipitation and 52 years （1951 2002） agricultural drought of the region, including tire provinces： Shaanxi, Gansu, Ningxia, Qinghai and Xinjiang. The result shows that the drought disaster is increasing and the most serious were in the 1970s and 1990s, and main agricultural drought is a great disaster incident. The regression prediction equation of drought and flood grades and agricultural drought areas grades are set up by the harmonic wave method, and forecasting the drought will lighten during the first ten years of the 21st century.

Holocene vegetational and climatic variation in westerly-dominated areas of Central Asia inferred from the Sayram Lake in northern Xinjiang,China

Changes in the vegetation and climate of the westerly-dominated areas in Central Asia during the Holocene were interpreted using pollen-assemblages and charcoal data from a 300-cm-long sediment core of the Sayram Lake,northern Xinjiang.Accele-rator Mass Spectrometry(AMS) radiocarbon dating methods were applied to bulk organic matter of the samples.Artemisia spp./Chenopodiaceae ratios and results from principal component analysis were used to infer that the lake basin was dominated by desert vegetation before ca.9.6 cal.ka BP,which suggests a warm and dry climate in the early Holocene.Desert steppe/steppe expanded during 9.6-5.5 cal.ka BP,indicating a remarkable increase both in the precipitation and temperature during the mid-Holocene.Desert vegetation dominated between 6.5 and 5.5 cal.ka BP,marking an extreme warmer and drier interval.The steppe/meadow steppe recovered,and temperatures decreased from 5.5 cal.ka BP in the late Holocene,as indicated by the increased abundance of Artemisia and the development of meadows.Holocene temperatures and moisture variations in the Sayram Lake areas were similar to those of adjacent areas.This consistency implies that solar radiation was the main driving factor for regional temperature changes,and that the effect of temperature variations was significant on regional changes in humidity.The evolution of climate and environment in the Sayram Lake areas,which were characterized as dry in the early Holocene and relatively humid in the middle-late Holocene,are clearly different from those in monsoonal areas.Dry conditions in the early Holocene in the Sayram Lake areas were closely related to decreased water vapor advection.These conditions were a result of reduced westerly wind speeds and less evaporation upstream,which in turn were caused by seasonal changes in solar radiation superimposed by strong evaporation following warming and drying local climate.

Climate change regionalization in China(1961–2010)

Since climatic condition is the important foundation for human subsistence and development and the key factor in sustainable development of economy and society, climate change has been a global issue attracting great attentions of politicians, scientists, governments, and the public alike throughout the world. Existing climate regionalization in China aims to characterize the re gional differences in climate based on years of the mean value of different climate indexes. However, with the accelerating climate change nowadays, existing climate regionalization cannot represent the regional difference of climate change, nor can it reflect the disasters and environmental risks incurred from climate changes. This paper utilizes the tendency value and fluc tuation value of temperature and precipitation from 1961 to 2010 to identify the climate change quantitatively, and completes the climate change regionalization in China （1961-2010） with county administrative regionalization as the unit in combination with China＇s terrain feature. Level-I regionalization divides China＇s climate change （1961-2010） into five tendency zones based on the tendency of temperature and precipitation, which are respectively Northeast China-North China warm-dry trend zone, East China-Central China wet-warm trend zone, Southwest China-South China dry-warm trend zone, Southeast Ti- bet-Southwest China wet-warm trend zone, and Northwest China-Qinghai-Tibet Plateau warm-wet trend zone; level-lI region- alization refers to fourteen fluctuation regions based on level-I regionalization according to the fluctuation of temperature and precipitation.