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371.
用RINEX HO软件计算GPS载波相位观测值中的高阶(二阶和三阶)电离层延迟,在此基础上组成GPS双差观测值中的高阶电离层延迟(ΔIH)p,qi,g。讨论了(ΔIH)p,qi,g与地磁纬度、基线长度、基线方向及太阳活动水平间的关系。在其他条件均相同的情况下,用Bernese 5.0软件分别对进行了高阶电离层延迟改正的观测值和未进行高阶电离层延迟改正的观测值进行基线解算,求得高阶电离层延迟对基线向量解的影响ΔbH。结果表明,ΔbH的数值很小,在一般情况下可忽略不计。ΔbH与基线长度及太阳活动水平等因素间并无必然联系,但随着时段的减小,ΔbH会随之增大。 相似文献
372.
DIAGNOSTIC ANALYSIS OF A RAINSTORM IN SHANDONG PENINSULA INFLUENCED BY A DISTANT TROPICAL DEPRESSION
Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July 27, 2006 in Shandong Peninsula has been analyzed. The results show that there are three severe convective cloud clusters during the heavy rainfall. The uprightness of coupling pattern between upper-layer jet and low jet and a divergence area, which appeared in the right of upper-layer jet, provided favorable environmental conditions for convective cloud clusters. The strong convective weather happens over the prefrontal warm sector and the storm rainfall mainly distributes in the front of a high-energy area.Positive vorticity distribution and transportation of warm advection in low levels provide dynamic and thermal conditions for the rainstorm. The spatial-temporal evolvements of physical variable fields and MPV2 as the horizontal component of moist potential vorticity show that the rain intensity change is determined by upper and low level jets and the area of MPV2>0 occurs at the front of the low jet cores. 相似文献
373.
374.
古代与现代海底黑矿型块状硫化物矿床矿石地球化学比较研究 总被引:33,自引:1,他引:33
选择西南太平洋冲绳海槽现代海底烟囱硫化物矿床、日本小坂矿山上向黑矿(第三纪)和中国西南呷村黑矿型矿床(三叠纪)进行了矿石地球化学比较研究。黑矿型矿床矿石吨位-品位模式与其他火山成因块状硫化物(VMS)矿床类似,矿田(20-50km^2)矿石吨位与单个喷气-沉积型(Sedex)矿床相当,金属总量4-6Mt,为矿田范围内热液流体搬运的最大金属量。与洋脊环境VMS矿床相比,岛弧裂谷环境产出的黑矿型矿床相 相似文献
375.
钓鱼岛石是在我国台湾省钓鱼岛附近海域海底表层沉积物中发现的一种新矿物。钓鱼岛石为无色淡绿色到,薄板状,一轴晶负光性,晶体很小,一般在0.4×0.2×0.03mm~3以下,D=3.30,H_(v15)=1392.8kg/mm~2。电子探针定量分析(以相应氧化物为标样)结果(%):Na_2O4.54、Al_2O_3 93.00、Cr_2O_31.95、MgO0.10、CaO 0.10、SiO_2 0.23、K_2O 0.12,总量100.04。以氧为17计算的化学式为(Na_(0.87) K_(0.02) Mg_(0.02) Ca_(0.01);)_(0.92)(Al_(10.84)Cr_(0.15)Si_(0.02))_(11.01)O_(17)。经四圆单晶衍射证明,该矿物为六方晶系,空间群为P6_3/mmc,a=b=5.602(1)Ac=22.626(5)A,α=β=90°,γ=120°。 相似文献
376.
In this paper, we mainly summarize and review the progresses
in recent climatological studies (by CMSR, IAP/CAS and some associated
domestic and international institutions) on the interannual and
interdecadal variabilities of monsoon troughs and their impacts on
tropical cyclones and typhoons (TCs) geneses over the western North
Pacific Ocean. The climatological characteristics of monsoon troughs
and four types of circulation patterns favorable to TCs genesis over
the western North Pacific Ocean in summer and autumn are given in this
paper. It is also shown in this paper that the monsoon trough over the
western North Pacific Ocean has obvious interannual and interdecadal
variabilities. Especially, it is revealed in this paper that the
interannual and interdecadal variabilities of the monsoon trough over
the western North Pacific Ocean influence the TCs genesis not only
through the impact on distributions of the vorticity in the lower
troposphere and the divergence in the upper troposphere, the water
vapor in the mid- and lower troposphere and the vertical shear of wind
fields between the upper and lower troposphere over the western North
Pacific Ocean, but also through the dynamical effects of the transition
between convectively coupled tropical waves and providing disturbance
energy. Besides, some climatological problems associated with TCs
activity over the western North Pacific Ocean that need to be studied
further are also pointed out in this paper. 相似文献
377.
A Study on a Heavy Rainfall Event Triggered by an Inverted Typhoon Trough in Shandong Province 总被引:2,自引:0,他引:2 下载免费PDF全文
A heavy rainfall event that occurred in Shandong Province in 26 28 August 2004 was caused mainly by Typhoon Acre and cold air activities related to a westerly trough. The event was triggered by an inverted typhoon trough, which was closely associated with the intensification of the low-level southeasterly flow and the northward transport of heat and momentum in the periphery of the typhoon low. A numerical simulation of this event is performed using the nonhydrostatic mesoscale model MM5 with two-way interactive and triply-nested grids, and the structure of the inverted typhoon trough is studied. Furthermore, the formation and development mechanism of the inverted typhoon trough and a mesoscale vortex are discussed through a vorticity budget analysis. The results show that the heavy rainfall was induced by the strong convergence between the strong and weak winds within the inverted typhoon trough. Dynamic effects of the low-level jet and the diabatic heating of precipitation played an important role in the development of the inverted typhoon trough and the formation of the mesoscale vortex. The vorticity budget analysis suggests that the divergence term in the low troposphere, the horizontal advection term, and the convection term in the middle troposphere were main contributors to positive vorticity. Nonetheless, at the same pressure level, the effect of the divergence term and that of the adveetion term were opposite to each other. In the middle troposphere, the vertical transport term made a positive contribution while the tilting term made a negative contribution, and the total vorticity tendency was the net result of their counteractions. It is found that the change tendency of the relative vorticity was not uniform horizontally. A strong positive vorticity tendency occurred in the southeast of the mesoscale vortex, which is why the heavy rainfall was concentrated there. The increase of positive vorticity in the low (upper) troposphere was caused by horizontal convergence (upward transport of vorticity from the lower troposphere). Therefore, the development of the inverted typhoon trough and the formation of the mesoscale vortex were mainly attributed to the vorticity generated in the low troposphere, and also the vertical transport of vorticity from the low and middle troposphere. 相似文献
378.
379.
380.
早前寒武纪古地热状态的构造环境意义 总被引:2,自引:0,他引:2
区域变质作用是在造山运动中地热流和动力联合作用的体现。在早前寒武纪的造山带中,随着地壳的缩短,古地热流向构造边界聚敛,形成由高温到低温的区域变质相带序列,它既指示古地热流运移的方向,又是构造边界的指向。古地热流值的高低同构造环境的性质有关,如陆内裂陷带的区域变质仅达绿片岩相,而陆缘活动带的则可高达角闪岩相。古地热流从活动带的边界向中心运移,具有向心性,随着构造层的深埋,构成地热槽,它的片段则表现为地热斜。识别这些古地热状态,可为构造环境属性的鉴定提供有力的依据 相似文献