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971.
We describe one of possible mechanisms of the formation of anomalies of the cloud field over the North Atlantic and Europe
by using, as an example, the processes developed in the Atlantic-European sector during the natural synoptic season in the
spring of 1996. It is shown that the anomalies of the cloud field can be classified with the use of the index of the North
Atlantic oscillation and the latitude of the center of the Azorean maximum.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
972.
973.
Abstract. Boonea (= Odostomia) impressa is a common ectoparasite of oysters. In the laboratory, small oysters (Crassostrea virginica) parasitized by natural densities of B. impressa produced 75 % less new shell than unparasitized oysters. Shell deposition rates of previously parasitized oysters increased significantly after all B. impressa were removed. Thus, the decrease in growth rate, although significant, apparently was not permanent. B. impressa preferentially parasitized small, living oysters (≤2.5cm) in the field, even though a higher percentage of large, living oysters (>2.5cm) was available. The snails maintained an aggregated distribution on the oyster reef. The number of B. impressa per oyster clump was positively correlated with the number of living oysters per clump, however some clumps with few or no living oysters had many B. impressa. Thus, food availability only partially explained the pattern of distribution. B. impressa was very mobile. About 50 % of the population moved in one week. Reproduction occurred throughout the year with a peak period in May. Recruitment was greatest in July, however new recruits were observed throughout the year. The reduction in growth rate of parasitized oysters, the snaiľs propensity towards parasitizing small oysters and the snail's tendency to be contagiously distributed suggests that B. impressa potentially exerts a significant influence on the population structure and health of oyster populations. 相似文献
974.
M. Arockiasamy H. El-Tahan A.S.J. Swamidas W.E. Russell D.V. Reddy 《Ocean Engineering》1984,11(5):463-490
The paper presents an analytical and experimental study on the transient response of semisubmersibles to bergybit impact and the strength of bergybit ice to high strain-rate loadings. Two approaches have been proposed for the solution of the semisubmersible-bergybit interaction problem, one using the energy approach and the other using the conventional structural dynamics approach with initial velocity conditions. In addition the local behaviour of the impacted regions have been analysed for deformation and failure. Numerical results have been given for local behaviour of an impacted column and global behaviour of semisubmersible-bergybit system. Experimental study has been reported on the impact strength of iceberg ice at strain rates of 10−3, 10−2 and 10−1; the indentation impact strength of ice is found to be 3–4 times the unaixial compressive strength, at the same strain rate. 相似文献
975.
G. G. Matishov M. V. Nabozhenko I. V. Shokhin A. E. Zolotareva N. I. Bulysheva V. L. Semin V. V. Polshin V. V. Povazhnyi R. E. Verbitskyi E. V. Verbitskyi F. V. Sapozhnikov V. A. Spiridonov A. K. Zalota 《Oceanology》2013,53(3):374-376
The shelf zones of the Black Sea, Taman Bay, and the Sea of Azov are currently subjected to gross load related to the impact of invasive species, large-scale construction activities near the coast, intensive recreation activity, water pollution in large cities and ports, active navigation, unreasonable coastal arrangement, and dam construction. Another factor substantially affecting the composition of bottom sediments and, thus, the benthos environment is the terrigenous material carried by rivers in the course of catastrophic overflows. An example is the Kubansk flood in 2012, which significantly affected the sea coast near Novorossiysk, Gelendzhik, and Divnomorsk. The intensive onshore dumping results in the delivery of abundant allochthonous material, bottom silting causing changes in the dominants in the benthos associations, a decrease in the photic layer and the death of the phytobenthos, and also debris formation at the bottom. Debris can play the role of artificial reefs contributory for the formation of periphytic biocoenoses. 相似文献
976.
Appropriate conditions have been achieved for the accurate, rapid, and highly precise shipboard simultaneous determination of dissolved organic carbon and total dissolved nitrogen in seawater by high temperature catalytic oxidation. A nitrogen-specific Antek 705D chemiluminescence detector and a CO2-specific LiCor Li6252 IRGA have been coupled in-series with a Shimadzu TOC-5000 organic carbon analyser. Precision of both simultaneous measurements is ≤1.5%, i.e. ±1 μmol C l−1 and ±0.3 μmol N l−1, respectively. Quality of analysis is not compromised by vibrations associated with ocean going research vessels. 相似文献
977.
The most important feature of the distribution of the alkalinity and calcium in the Sea of Japan—the increase in the potential
alkalinity with depth under the conditions when the waters are supersaturated in relation to calcium carbonate—is considered.
It is demonstrated that this fact cannot be accounted for by the reaction of the formation-dissolution of calcium carbonate.
A new concept explaining the alkalinity distribution in the sea is proposed. According to it, the biological pump is the basic
process responsible for the alkalinity transport from the euphotic layer into the interior of the sea. Photosynthesis is the
driving force for this process. The role of the active element transporting the alkalinity is not calcium carbonate, as has
been claimed elsewhere, but extracellular polysaccharides (EPSs) produced by phytoplankton. EPSs bind to calcium and other
cations to form transparent exopolymer particles (TEPs). The proposed conception makes it possible to explain the following:
(a) the vertical flux of calcium carbonate that is independent of the super-saturation—undersaturation state of the ambient
water regarding calcium carbonate; (b) the existence of the calcium carbonate flux regardless of the nature of the plankton
skeletons; (c) the nonstoichiometric ratio between the alkalinity and calcium fluxes. 相似文献
978.
The underwater vocalizations of the beluga whale summering in Onega Bay (64°24′N, 35°49′E) were recorded in June–July of 2008.
The vocalizations were classified into five major whistle types, four types of pulsed tones, click series, and noise vocalizations.
To determine the relationship between the behavioral activity and the underwater vocalizations, a total of fifty-one 2 minute-long
samples of the audio records were analyzed in the next six behavioral contexts: directional movements, quiet swimming, resting,
social interactions, individual hunting behavior, and the exploration of hydrophones by beluga whales. The overall vocalization
rate and the percentage of the main types of signals depend on the behavior of the belugas. We suggest that one of the whistle
types (the “stereotype whistle”) is used by belugas for long-distance communications, while other whistle types (with the
exception of “squeaks”) and three types of pulsed tones (with the exception of “vowels”) are used for short distance communication.
The percentage of “squeaks” and “vowels” was equally high in all the behavioral situations. Thus, we assume that “squeaks”
are contact signals. “Vowels” have a specific physical structure and probably play a role in identification signals. A high
rate of the click series was observed in the process of social interactions. 相似文献
979.
A. I. Ryabinin S. A. Bobrova L. V. Saltykova E. A. Danilova 《Physical Oceanography》2012,21(5):320-328
We study the space-and-time variations of the delivery of fluxes of 26 elements (Na, K, Rb, Cs, Cu, Ag, Au, Ca, Sr, Ba, Zn,
Cd, Hg, Hf, Ta, As, Sb, Cr, Se, Mo, W, Mn, Br, Fe, Co and Ni) with atmospheric precipitations to the sea surface in the regions
of Sevastopol and the South Coast of Crimea. It is established A series of general regularities of the delivery of the sum
of these elements and their soluble and insoluble forms. We also give the characteristics of their space-time variability. 相似文献
980.
The diverse geodynamic conditions of the parental magma??s melting are responsible for the compositional diversity of the alkaline volcanics near the southwestern margin of Iberia. The petrological-geochemical data show that the volcanics of the Gorringe Bank originated within the continental plate. The parental melilitite melts depleted in silica and anomalously enriched with trace elements could have been generated only in deep settings with a low degree of metasomatically enriched mantle matter melting. The volcanic melilitite-nephelinite-phonolite series is widespread in alkaline provinces of the Eurasian, African, and other continental plates. The Ampere, Josephine, and other seamounts and islands of the region are largely composed of volcanic rocks belonging to the picrobasalt-hawaiite-mugearite association. Their parental magmas were generated within the oceanic plate at shallower depths under a higher degree of moderately enriched oceanic lithospheric mantle melting. Both series of volcanics were formed under the influence of mantle plumes. 相似文献