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根据IGY/IGC期间全球地磁台网以及中国地磁台站的资料,计算出每-UT小时的Sq外源和内源电流体系.对Sq电流体系UT变化和经度效应的分析研究表明,Sq外源电流体系的空间图案没有显著的UT变化,电流涡焦点的地理纬度与磁赤道有密切关系,其变化范围,北半球为25°-35°N,南半球为30°-42.5°S.外源电流总强度的平均值为229kA(北半球)和173kA(南半球),其变化范围为±50kA(北半球)和±40kA(南半球).Sq内源电流体系的图案和强度有显著的UT变化,电流体系焦点纬度有类似于外源电流系的变化.在大西洋、印度洋、北太平洋地区,内源电流体系的总强度明显小于大陆地区的内源电流强度,表明这些大洋地区上地幔电导率低于大陆地区. 相似文献
13.
用中国地磁台站的资料,研究了S_q逐日变化的形态学特征,用理论模型计算了磁层环电流、部分环电流、场向电流、磁尾电流、Chapman-Ferraro电流的地磁效应.在消除了这些磁层电流体系的影响之后,得到了电离层潮汐风发电机电流产生的磁场S_q变化.对1973年的资料研究表明,S_q发电机电流的逐日变化主要表现在强度上,即使在磁扰期间,也可以分离出形态稳定的S_q变化.由此提出了一种新的地磁指数——S_q指数,用来描述S_q发电机电流强度的逐日变化. 相似文献
14.
Regional studies of Sq variations measured at five permanent observatories in Argentina were performed to estimate the distribution of the electrical conductivity of the upper and mid-mantle, reaching a depth of approximately 800 km. After separating the total field into its parts of external and internal origin, the in duced field was modeled, applying two-dimensional techniques. Additionally, induction arrows and an equivalent apparent resistivity curve were calculated A north-south heterogeneity was detected, showing an increase of the conductivity of the shallower layers north of the profile, which may be related to the presence of high volcanic activity in the area.Also at CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas). 相似文献
15.
本文用不同经度的7对中低纬台站水平磁场分量H,求得1965年随世界时(UT)变化的Sq指数(一种描述Sq电离层发电机电流强度的地磁指数).结果表明,Sq发电机电流不仅有显著的逐日变化,而且有很大的UT变化.UT变化主要表现在电流总强度的强弱和电流涡焦点纬度移动两方面,这意味着决定发电机过程的太阳潮汐风场和电离层电导率随UT而变.用求得的Sq指数重新构造出的Sq变化与观测值符合得较好,它不仅显示出Sq幅度逐日变化的特点,而且还能复现出Sq形态的某些逐日变异性. 相似文献
16.
?????????????????????????1997??11??8?????????????o????Ч?????????????????????????λ?????????Ч????????仯??????????????????????Ч?????????仯????????λ?????????????????????????Ч????????仯??????????λ???????????????????? 相似文献
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????????????????й??????????????????????LSQR??WLSQR??MLS?????????????????????????????????????????????沨?????????в??????????????????????????????????????????????? 相似文献
19.
????????????????????????????????????BP???????????????????人???????????????????????????????????BP??????????????????г????????????????????????о??????????BP???????????????????????????????????????????????? 相似文献
20.
E. Gontikaki D.J. MayorB.E. Narayanaswamy U. Witte 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(2):160-172
The response of a sub-arctic, deep-sea macrofaunal community to a simulated food sedimentation event was studied by means of a stable isotope “pulse-chase” experiment. A food pulse was simulated by adding 500 mg C m−2 of 13C-labelled diatoms, Chaetoceros radicans, to sediment cores retrieved from 1080 m in the Faroe-Shetland Channel. Carbon uptake by specific macrofaunal groups was quantified after 3 and 6 days of incubation. The carbon uptake of the dominant taxon (Polychaeta) was quantified at the genus-, and where possible, species-level, representing a data resolution that is rare in deep-sea tracer studies. The macrofaunal community reacted rapidly to the diatom addition, with 47% and 70% of the animals illustrating 13C-enrichment after 3 and 6 days, respectively. Approximately 95% of C uptake was located in the upper 2 cm due to the particularly shallow vertical distribution of the macrofaunal community and the nonexistent tracer subduction by burrowing species. Polychaetes of the families Ampharetidae and Cirratulidae were among the most heavily labelled with above background enrichment reaching 1300‰. Approximately 0.8 and 2.0 mg C m−2 were processed by the macrofauna after 3 and 6 days, representing 0.2% and 0.4% of the added carbon, respectively. It was not possible to differentiate sub-surface deposit-feeding polychaetes from predator/scavenger- and omnivorous polychaetes using their natural ??15N signatures. However, the combination of natural abundance ??15N data and 13C-labelling experiments proved to be useful for elucidating trophic relations in deep-sea food webs. This study confirms that macrofauna play an active role in the short-term carbon cycling at bathyal depths even at sub-zero temperatures and highlights the need for detailed knowledge of the community structure in understanding carbon processing patterns and early diagenesis of organic matter in marine sediments. 相似文献