环青海湖地区天然牧草对水分条件的反应特性

本文利用铁卜加1987-1996年的气象、牧草资料，对环青海湖地区山地草原草场5种天然牧草在不同水分丰枯年份的生长、发育和产量形成状况进行对比分析，结果表明：环湖地区山地草原草场中紫花针茅、冷地早熟禾、干生苔草、猪毛蒿、天山赖草、杂草产量比例为8：15：15：16：18：28。5种天然牧草的发育期、生长高度和产量形成对水分条件表现出不同的反应，天山赖草最耐旱；干生苔草次之；猪毛蒿和紫花针茅的抗旱性相当；冷地早熟禾对水分条件的反应最为敏感。     

内蒙古典型草原水分条件与天然牧草产量的关系

水分是干旱、半干旱地区天然牧草生长的限制因子。分析水分条件与牧草产量的关系是确定旱灾指标、评价草原生态环境优劣的基础。利用内蒙古典型草原区3个站点近15年的天然牧草、土壤水分和气象观测资料，计算了降水量、土壤水分和耗水量与不同时期牧草产量的相关系数，分析了各水分因子相关性的时空分布规律。得出：土壤水分与产量的相关好于降水量；降水与产草量多呈二次曲线变化，土壤水分和耗水量与产草量多呈直线变化;相关程度随生长进程的推进，有逐渐增强的趋势     

气候变化对青海天然牧草影响研究

根据青海省4个牧业气象代表站点1988-2005年天然牧草数据和同期气候资料,分析了青海天然牧草生长发育与气象条件的关系,探讨了气候变化对青海省牧草发育期、高度及产量形成的影响。研究表明:青南东部地区影响牧草返青出现的主要因素是热量条件,而青南西部和环湖地区牧草返青期的早晚主要受制于水分条件;两地区牧草黄枯期出现的迟早与日平均气温稳定通过5℃的终日相接近;在干旱、半干旱地区,天然牧草产量形成的主要因素取决于水分条件,年降水越多,牧草产量越高;青南东部的半湿润地区,温度对产量的影响大于降水对产量的影响。在全球气候变暖的背景下,青海省半湿润牧业区,随气温升高,牧草产量有所增加,草场载畜量有所上升;但在干旱、半干旱牧业区,气候变暖加剧草地水分的散失,牧草的生长发育受阻,产草量下降,同时,优良牧草在草场中的比例下降,杂类草的数量和比例上升,草场朝不良方向演替,呈现退化趋势。     

青海气候条件对牧草再生性影响的研究

选取1994～2001年河南、甘德两站牧草再生草资料及同期气象资料，通过分析同一地区不同时期及同一时期不同地区气候条件对牧草再生性的影响，建立了牧草再生草产量气候模式，讨论了再生草增、减产的气候条件。研究得出：同一地区不同时期和同一时期不同地区因气候条件不同，割草不一定能增产。     

青海气候条件对牧草再生性影响的研究

本选取1994～2001年河南、甘德两站牧草再生草资料及同期气象资料，通过分析同一地区不同时期及同一时期不同地区气候条件对牧草再生性的影响，建立了牧草再生草产量气候模式，讨论了再生草增、减产的气候条件。经研究得出：同一地区不同时期和同一时期不同地区因气候条件不同，割草不一定能增产。     

呼伦贝尔市天然牧草生物量与气候条件的定量关系

利用30年气象资料和15年的天然牧草观测资料，采用相关分析法将牧草的整个生育期分为缓慢生长-积极生长-缓慢生长3个阶段；应用积分回归统计方法得出：牧草缓慢生长期为返青-展叶时期，光、温、水对牧草产量的影响基本呈正效应。牧草积极生长期为牧草拔节-开花时期，温度、日照基本满足牧草的生长发育需要，水分条件是主要矛盾。第三个阶段（牧草缓慢生长期）为牧草灌浆期-成熟时期，此时光、水对牧草产量的影响基本星负效应，气温对牧草产量的影响基本呈正效应。     

气候变化对环青海湖地区天然牧草影响研究

近47a来环青海湖地区的气候变化特征及其对环湖盆地草地生态环境的影响,分析表明：环青海湖地区年平均温度升高、年蒸发量减少比较显著,而降水量呈增加趋势,气候有向暖湿化过渡的趋势。随着气候变化,环湖盆地天然草地植被盖度,高度和产量变化明显。在全球气候变暖的背景下,环青海湖地区,随气温升高、降水增加牧草产量有所增加,     

青海湖环湖地区秋季人工增雨的综合效果分析

据2001年秋季人工增雨资料，结合历年秋季降水资料，从秋雨春用、影响地下水位涵养、青海湖水量盈亏等方面分析了秋季人工增雨的综合效益；并着重分析了秋季降水与环湖地区土壤水分贮量以及第二年春季环湖天然草场土壤墒情、牧草返青时间、生长状况及产量的关系。分析表明：秋季降水越多，环湖区土壤水分贮存量越多，翌年土壤墒情越好、牧草返青越早且牧草产量越高。     

乌审旗半荒漠区土壤水分变化对牧草生长发育的影响——以赖草为例

基于乌审召牧业气象试验站29a(1981—2009年)连续观测资料,分析了该地区土壤水分、主要牧草的发育期、产量的变化趋势,同时对土壤水分变化与牧草生长发育的影响进行相关分析。结果表明,对于10~50cm土层而言,其年平均土壤重量含水率均呈下降趋势,而且随着土层深度的增加下降趋势越来越明显(P0.05);赖草的返青期、黄枯期均呈推后趋势,开花期为提前趋势,生育期呈明显的延长趋势(P0.01)。赖草干鲜重均呈明显的下降趋势(P0.01)。土壤含水量与半荒漠牧草生育期、干鲜重的相关性不是很明显。     

荒漠草原造林气候生态效应研究

本项目利用荒漠草原地区现有林片网，采用平行对比观测法，应用实测资料计算分析了荒漠草原地区不同结构的片状防护林对造林区内草地小气候以及牧草的群落结构、生长发育状况，水分利用状况，载畜量和土壤肥力等方面的影响。结果表明，造林明显地改善了造林区域内的小气候条件，引起了群落优势种的更替，即由以小叶锦鸡儿、冷蒿、针茅、隐子草为主要优势种变为以羊草为主要优势种的群落，草群高度和盖度显增大。主要牧草种的出苗或返青期提早1－2天，生长速率增大53－250％。水分利用率提高100－150％，鲜草增产100－200％，载畜量增加100－200％。造林区域为0－10cm土壤有机质含量增加4－88．9％，0－30cm土壤全氮量降低1．1－36．3％。造林结构以密度为1．5×1．5m或2×3m郁闭度为0．3－0．65的片林，其气候生态效应最佳。     

加强业务管理提高测报质量

我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格.     

Addressing the necessity of the registration of the effects of causal mechanics in the example of a simple barotropic model of the atmosphere

Summary Considering the effects of causal mechanics on geophysical problems enables us to explain a number of phenomena, which cannot be explained from conventional positions. This paper shows that the introduction of the force of causality in a simple barotropic hydrodynamic model of weather forecasts results in the outcomes, which, on the one hand, can not be described from the positions of classical hydro-thermodynamics, whilst on the other hand, exist in nature.     

Modeling the evolution of the family of Mediterranean cyclones using the regional model of the atmosphere

Due to the complex orography and the presence of the moisture-saturated air, the Mediterranean region is characterized by the increased baroclinic and convective instability, that leads to the sudden cyclogenesis and the formation of dangerous weather phenomena. The results are given of the investigation of formation mechanisms of Mediterranean cyclones, peculiarities of stages of their evolution and dynamical processes, which occur throughout the atmosphere, using the regional numerical ETA model of the atmosphere by the example of individual cases of the cyclogenesis over the Mediterranean Sea. It is revealed that the cold Arctic air outbreak (the intrusion of the cold Arctic air) to the south of the Western Europe, leading to the formation of the areas of the baroclinic instability and the increased moisture content of the air in the area of the vortex origin, favors the cyclogenesis. The use of the vertical coordinate η in the model enabled to compute more precisely the vertical wind speed, therefore, the influence of the orography on the moisture content and precipitation increase became pronounced. The transformation of the structure of meteorological fields in the course of the development of vortexes is considered. The computation of the helicity is made, and it is shown that this characteristic can be one of the earliest predictors of cyclogenesis.     

Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230...     

流场配置及地形对西南低涡形成的动力作用

本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用.     

On the determination of the height of the Ekman boundary layer

The heighth of the Ekman turbulent boundary layer determined by the momentum flux profile is estimated with the aid of considerations of similarity and an analysis of the dynamic equations. Asymptotic formulae have been obtained showing that, with increasing instability,h increases as ¦¦^1/2 (where is the non-dimensional stratification parameter); with increasing stability, on the other hand,h decreases as ^–1/2. For comparison, a simple estimate of the boundary-layer heighth _u determined by the velocity profile is given. As is shown, in unstable stratification,h _u behaves asymptotically as ¦¦^–1, i.e., in a manner entirely different from that ofh .     

接地降阻剂的PH值的探讨

1引言我国执行接地降阻剂测试的技术标准是全国电力系统起草的:“接地降阻剂暂行技术条件修改稿”。在技术要求中要求接地降阻剂的酸碱值应在7￣12范围内。在实际使用中发现该技术要求对接地降阻剂的酸碱值要求范围并不合理,需要分析和讨论。2接地降阻剂的PH值接地降阻剂的酸碱性对地网的使用寿命至关重要,为了不让接地降阻剂腐蚀接地体或者减弱接地降阻剂对接地体的腐蚀,在接地降阻剂测试的技术要求中,对接地降阻剂的酸碱度有一定的限制。国内各厂家用于生产接地降阻剂的偏弱酸的盐类进行了对镀锌钢材腐蚀的试验,结果是这些镀锌钢材均受到…     

阴山山脉对内蒙古中部地区气象要素影响初探

文章选用阴山山脉山北乌拉特后旗、白云、达茂旗、苏尼特左旗、化德,山南杭后旗、包头、呼和浩特、察右前旗、兴和1971—2000年气温、降水量、天气现象等资料进行对比分析,得到阴山山脉对内蒙古自治区中部地区气象要素影响初步结论。     

2003年黑龙江省主要灾害性天气及其对作物生长发育和粮食产量的影响

利用40年气温、降水资料和历史上千旱、低温严重的年份与2003年进行对比分析．评估黑龙江省2003年发生的严重灾害的分布范同,灾害程度,及其对主要粮食作物生长发育和产量的影响。得出2003年的灾害是30年未遇的全省性严重灾害年,各种灾害对各种作物都产生了不同程度的影响,受害最重的作物是小麦。     

On the forecast of the onset and end of the convective season in the Amazon

Summary ?Some features of the climate system that can be considered predictors of the onset and end of the convective season over the Amazon were identified using one-month lag correlations and field composites. The fields analyzed were sea surface temperature (SST), outgoing long-wave radiation (OLR), vertical velocity and upper tropospheric winds. Warm (cold) anomalies in the SST in the tropical North Atlantic and the Caribbean Sea tend to be associated with delayed (early) onsets. Likewise, there is a tendency towards a delayed (early) end of the convective season with cold (warm) anomalies in these ocean regions. In addition, the SST in the cold tongue region of the equatorial Pacific is negatively, though weakly correlated with the onset date. The signal of this SST is more evident in the case of the end date, which is earlier with respect to its mean date in most of El Ni?o cases. The convective activity intensity itself conditions the onset and the end of the convective season, as it is evidenced by the behavior of the OLR and the vertical velocity fields. The more (less) intense the convective activity over South America during the preceding month, the earlier the onset and the later the end of the convective season on the Amazon region. The prediction of the onset and end dates of the convective season in the Amazon region was explored using a simple multiple regression technique based on the variables that have shown precursor signals with respect to these dates. The correlation coefficient between the predicted and the observed onset date is 0.81, and in the case of the end date, it is 0.76. The skill to predict early, delayed and normal categories was high, since in more than two thirds of the cases the category was successfully predicted, and there were no predictions of categories opposed to those observed. Received July 23, 2001; revised February 22, 2002; accepted April 26, 2002