排序方式： 共有55条查询结果，搜索用时 15 毫秒
41.
42.
The internal stability of the fractal structure of interstellar clouds in the Galaxy is considered. The conditions under which
gravitational interactions between components lead to disruption of the fractal structure are clarified. Model numerical calculations
and analytical estimates of the characteristic time of decay of structures are made. It is found that this time is on the
same order as the lifetime of interstellar molecular clouds determined from observations.
Translated from Astrofizika, Vol. 41, No. 1, pp. 81–90, January-March, 1998. 相似文献
43.
Morozov E. G. Frey D. I. Neiman V. G. Makarenko N. I. Tarakanov R. Yu. 《Doklady Earth Sciences》2019,486(2):659-662
Doklady Earth Sciences - In April 2017 and October 2018, a Russian expedition on the R/V Akademik Sergei Vavilov in the Southwest Atlantic carried out measurements of the temperature, salinity, and... 相似文献
44.
45.
R. Yu. Tarakanov 《Oceanology》2012,52(2):157-170
It is shown on the basis of the data of the Russian Academy of Sciences expeditions in 2003–2010, the historical CTD database,
the WOCE climatology, and the satellite altimetry that the area of the Scotia Sea and the Drake Passage is even a greater
significant orographic barrier for the eastward Antarctic Circumpolar Current (ACC) than was previously thought. It is the
current concept that this barrier is the most important for the ACC; it consists of three obstacles: the Hero Ridge with the
Phoenix Rift, the Shackleton Ridge, and the North Scotia Ridge with the relatively shallow eastern part of the Scotia Sea.
Despite the fact that all three obstacles are permeable for the layer of the Circumpolar Bottom Water (CBW; 28.16 < γ
n
< 28.26) being considered the lower part of the circumpolar water, the circulation in this layer throughout the Scotia Sea
and the Drake Passage quite substantially differs from the transfer by the surface-intensified ACC jets. Herewith, the upper
CBW boundary is the lower limit of the circumpolar coverage of the ACC jets. This result is confirmed by the near zero estimate
of the total CBW transport according to the three series of the LADCP measurements on the sections across the Drake Passage.
It is shown that the transformation (cooling and freshening) of the CBW layer, which occurs owing to the flow of the ACC over
the Shackleton Ridge, is associated with the shape and location of the ridge in the Drake Passage. The high southern part
of this ridge is a partially permeable screen for the eastward CBW transport behind which the colder and fresher waters of
the Weddell Sea and the Bransfield Strait of the same density range as the CBW penetrate into the ACC zone. The partial permeability
of the Shackleton Ridge for the CBW layer leads to the salinization of this layer on the eastern side of the ridge and to
the CBW’s freshening on the western side of this ridge, which is observed across the entire Drake Passage. 相似文献
46.
The currents in the central part of the Drake Passage are investigated by analyzing the CTD and SADCP data over the section
across the Drake Passage occupied in November 2010 and satellite altimetry data. All eight of the jets of the Antarctic Circumpolar
Current, which are currently identidifed, were resolved by the section. The velocities and water transports of these jets
are estimated. Three synoptic scale eddies with different vertical structures were revealed; hypotheses on the physical nature
of these eddies are discussed. 相似文献
47.
Koshlyakov M. N. Repina I. A. Savchenko D. S. Tarakanov R. Y. Taroyan V. K. 《Oceanology》2019,59(2):171-181
Oceanology - Satellite altimeter observation data collected over 22 years are used to analyze the structure and variability of mesoscale fluctuations of ocean currents in the Drake Passage and... 相似文献
48.
R. Yu. Tarakanov 《Oceanology》2010,50(1):1-17
The quantitative properties and circulation of the lower layer of circumpolar water in the Scotia Sea with density 28.16 <
γ
n
< 28.26 (potential temperature 0.9° > θ > 0.2°C) are investigated using the original procedure for determination of boundaries
between water masses. The primary objective of this work is data analyses of four Russian sections, which were occupied in
the vicinity of the Shackleton Fracture Zone in 2003, 2005, and 2007. It is shown that the ridges in the Hero and Shackleton
fracture zones essentially constrain overflow of the lower layer of circumpolar water, and thereby, they produce the conditions
to the east of the Shackleton Ridge for transformation (freshening and warming) of this layer reaching the northern side of
the Antarctic Circumpolar Current. These ridges also promote formation of several quasi-permanent and semi-enclosed abyssal
and deep-water eddies adjacent to these ridges. The estimation of overflow of the lower part of the investigated layer with
density 28.23 < γ
n
< 28.26 (0.9° > θ > 0.2°C) through the Shackleton Ridge based on LADCP measurements in 2007 is 0.5 Sv (0.1 Sv) to the east
(west). The upper part of the overflow is estimated as 8.0 (7.9) Sv. Thus, the total transport of the lower layer of circumpolar
water through the ridge is practically zero. It is confirmed by LADCP measurements carried out on the section across the Drake
Passage in 2003. 相似文献
49.
Eugene G. Morozov Roman Yu. Tarakanov Dmitry I. Frey Tatiana A. Demidova Nikolay I. Makarenko 《Journal of Oceanography》2018,74(2):147-167
The goal of this paper is to study the flows of Antarctic Bottom Water through the fracture zones in the northern part of the Mid-Atlantic Ridge based on the Conductivity-Temperature-Depth and Lowered Acoustic Doppler Current Profiler observations in 2014, 2015, and 2016. We measured the thermohaline properties and velocities and analyzed the flows of bottom water in the Strakhov, Bogdanov, nameless (07°28′N), Vernadsky, Doldrums, Arkhangelsky, Ten Degree, Vema, Marathon, Fifteen Twenty, and Kane fracture zones. These abyssal channels connect the deep basins of the East and West Atlantic. In addition to the known fact that the main portion of water propagates through the Vema Fracture Zone (11°N), we estimated that additionally a half of this volume propagates through the other fractures. Nevertheless, the pathway for the coldest water is located in the Vema Fracture Zone. Velocities of bottom currents in this fracture reach 45 cm/s. We found strong difference in the structure and transport through the Vema Fracture Zone based on four sections across the fracture occupied in 3 years from 2014 to 2016. The transport varies from 0.7 to 1.2 Sv. The core of maximum velocity in the main channel of this fracture changes its depth between 4000 m and the bottom at 4650 m. The total transport through the other fracture zones is as high as 0.48 ± 0.05 Sv. 相似文献
50.
Izvestiya, Atmospheric and Oceanic Physics - An algorithm for distinguishing closed multicore circulations from digital maps of dynamic topography (DT) is described. The algorithm is based on the... 相似文献