Seasonal Variations of the East Asian Subtropical Westerly Jet and the Thermal Mechanism   总被引：3，自引：0，他引：3  

KUANG Xueyuan  ZHANG Yaocun  LIU Jian 《Acta Meteorologica Sinica》2007,21(2):192-203

The seasonal variations of the intensity and location of the East Asian subtropical westerly jet (EAWJ) and the thermal mechanism are analyzed by using NCEP/NCAR monthly reanalysis data from 1961 to 2000. It is found that the seasonal variation of the EAWJ center not only has significant meridional migration, but also shows the rapid zonal displacements during June-July. Moreover, there exists zonal inconsistency in the northward shift process of the EAWJ axis. Analysis on the thermal mechanism of the EAWJ seasonal variations indicates that the annual cycle of the EAWJ seasonal variation matches very well with the structure of the meridional difference of air temperature, suggesting that the EAWJ seasonal variation is closely related to the inhomogeneous heating due to the solar radiation and the land-sea thermal contrast. Through investigating the relation between the EAWJ and the heat transport, it is revealed that the EAWJ weakens and shifts northward during the warming period from wintertime to summertime, whereas the EAWJ intensifies and shifts southward during the cooling period from summertime to wintertime. The meridional difference of the horizontal heat advection transport is the main factor determining the meridional temperature difference. The meridional shift of the EAWJ follows the location of the maximum meridional gradient of the horizontal heat advection transport. During the period from April to October, the diabatic heating plays the leading role in the zonal displacement of the EAWJ center. The diabatic heating of the Tibetan Plateau to the mid-upper troposphere leads to the rapid zonal displacement of the EAWJ center during June-July.  相似文献   

福建省中亚热带农业气候系统功能评价的数学模型   总被引：7，自引：0，他引：7  

晏路明 《自然资源》1991,(1):41-47

  相似文献   

充分利用气候资源 合理调整农业结构   总被引：1，自引：0，他引：1  

张海峰 《河南气象》2005,(2):34-35

根据河南各地气候资源及不同作物生育关键期气象指标和气象灾害指标，将河南省分为北亚热带气候温热湿润多雨地区和暖温带气候温暖多早涝地区，并提出合理利用气候资源、因地制宜地调整农业生产结构等的建议。  相似文献   

亚热带富铁土的磁学性质及其磁性矿物学   总被引：7，自引：3，他引：4  

卢升高 《地球物理学报》2000,43(4):498-504

通过５５个亚热带富铁土的磁化率（χ）、频率磁化率(χ_ｆｄ)、非滞后剩磁（ＡＲＭ）和饱 和等温剩磁（ＳＩＲＭ）等磁性参数测定,结合氧化铁化学形态分析和矿物鉴定,初步明确了亚热 带富铁土的磁学特征及其磁性矿物．磁测数据表明富铁土中存在强磁性的矿物,其磁化率χ 与土壤游离氧化铁（Ｆｅ_ｄ）含量呈极显著指数正相关（Ｒ^２＝０．５９７１）,频率磁化率χ_ｆｄ与土壤游离氧 化铁含量呈极显著直线正相关（Ｒ^２＝０．４２８９）．富铁土的χ_ｆｄ和非滞后磁化率χ_ＡＲＭ。值表明土壤 中的磁性矿物以超顺磁性（ＳＰ）和稳定单畴（ＳＳＤ）颗粒为主,富铁上的χ和χ_ＡＲＭ呈极显著直线 正相关（Ｒ^＝ ０．９４２９）,证明富铁土的磁性是由风化成土过程产生的 ＳＰ和 ＳＳＤ磁性颗粒贡献 的．矿物磁测结合Ｘ－衍射证明富铁土中的氧化铁矿物由赤铁矿、磁赤铁矿和针铁矿组成。  相似文献   

神农架大九湖表层泥炭碳、氮、磷含量的空间分布特征及其控制因素     

阿木铁布  张一鸣  黄咸雨 《湿地科学与管理》2023,(2):20-25

为了解亚热带泥炭地碳氮磷含量的空间分布模式及其影响因素,在神农架大九湖泥炭地采集147份表层泥炭样品进行总有机碳含量(TOC)、总磷含量(TP)和总氮含量(TN)测试和理化参数分析,探究表层泥炭碳氮磷的空间分布特征及其控制因素。结果表明:大九湖表层泥炭TOC含量变化范围为3.51%~37.93%,TP含量变化范围为0.37~2.75 mg/g,TN含量变化范围为0.59~1.6mg/g。相关性分析表明:TOC含量与含水率(r=0.45,P<0.01)和TP含量(r=0.27,P<0.05)呈显著正相关,TP含量与干容重呈显著正相关(r=0.32,P<0.05),TN含量与各种理化参数的相关性均不显著。通过对比亚热带、热带、北方泥炭地的碳氮磷含量,发现相对于热带和北方泥炭地,亚热带泥炭地的TOC含量和TN含量更低,而TP含量更高。本研究为亚热带泥炭地的生态保护提供了关键的基础数据和参考。  相似文献   

巧用数学知识 智解地理问题     

徐成鹏  石肖韩 《地理教学》2014,(5)

正在给学生复习气候类型判读时,我举2013四川高考题(5~6题)为例。图1是北半球亚热带某地降水量逐月累计曲线图。读图回答1~2题。(2013年四川卷)  相似文献   

The Limiting Effect of Deep Soil Water on Evapotranspiration of a Subtropical Coniferous Plantation Subjected to Seasonal Drought简   总被引：4，自引：0，他引：4  

TANG Yakun  WEN Xuefa  SUN Xiaomin  ZHANG Xinyu  and WANG Huimin 《大气科学进展》2014,31(2):385-395

Seasonal drought is a common occurrence in humid climates.The year 2003 was the driest year during the period 1985-2011 in southeastern China.The objective of this study was to elucidate the impact of the exceptional drought in 2003,compared with eddy flux measurements during 2004-11,on the dynamics of evapotranspiration （ET） and related factors,as well as their underlying mechanisms,in a subtropical coniferous plantation in southeastern China.It was found that daily ET decreased from 5.34 to 1.84 mm during the intensive drought period and recovered to 4.80 mm during the subsquent recovering drought period.Path analysis indicated that ET was mainly determined by canopy conductance and deep soil water content （50 cm） during the intensive drought and recovering drought periods,respectively.The canopy conductance offset the positive effect of air vapor pressure deficit on ET when suffering drought stress,while the canopy conductance enhanced the positive effect of air temperature on ET during the late growing season.Because the fine roots of this plantation are mainly distributed in shallow soil,and the soil water in the upper 40 cm did not satisfy the demand for ET,stomatal closure and defoliation were evident as physiological responses to drought stress.  相似文献   

林海栾川     

崔世俊  张亚飞 《河南国土资源》2014,(10):60-60

不到栾川,不知道这里山有多高,沟有多深,林有多密。二亿四千万年前,气势恢宏的造山运动中,除馈赠给栾川得天独厚的地下宝藏外,大自然这个非凡的工匠还为这里矗立起了千姿百态的9251个山头,雕琢出蜿蜒曲折的8850条沟岔,开凿出604条奔腾跳跃的支流。造山运动推动伏牛山的抬升,造就了亚热带与温带两大气候区带的分界,使栾川处在夏无酷暑、冬无严寒的伏牛山腹地。  相似文献   

我们还剩多少红树林     

沙中土 《地图》2011,(1):8-15

红树林,是热带和亚热带沿海地区最常见的标志性生态部落,也是地球上最重要的生态系统之一,但是科学家从卫星遥感图中却看到了令人沮丧的迹象。由于被砍伐用来作为食物、燃料和药物,这种重要的滑海树林在很多地区已经日渐稀少。为了继续保护红树林这一重要的生态系统,科学家专门利用卫星遥感图编纂了这张范围最为广泛的全球红树林分布示意地图。  相似文献   

打洛：亚热带雨林掩映下的中缅边境     

伊瑜 《中国测绘》2011,(2):52-55

中缅边境云南南段的西双版纳、思茅、临沧3个地州,地处亚热带地区,以滇南勐腊县澜沧江畔中老边界处为起点．逐渐向西过南览河、南垒河,再向西北溯南卡江而上,直至镇康县怒江下游出境接萨尔温江处与潞西市中缅边界相交。  相似文献