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1.
The shedding of mesoscale anticyclonic eddies from the Alaskan Stream and westward transport of warm water 总被引：1，自引：0，他引：1
Konstantin Rogachev Natalya Shlyk Eddy Carmack 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2643
The south-flowing waters of the Kamchatka and Oyashio Currents and west-flowing waters of the Alaskan Stream are key components of the western sub-Arctic Pacific circulation. We use CTD data, Argo buoys, WOCE surface drifters, and satellite-derived sea-level observations to investigate the structure and interannual changes in this system that arise from interactions among anticyclonic eddies and the mean flow. Variability in the temperature of the upstream Oyashio and Kamchatka Currents is evident by warming in mesothermal layer in 1994–2005 compared to 1990–1991. A major fraction of the water in these currents is derived directly from the Alaskan Stream. The stream also sheds large anticyclonic (Aleutian) eddies, averaging approximately 300 km in diameter with a volume transport significant in comparison with that of the Kamchatka Current itself. These eddies enclose pools of relatively warm and saline water whose temperature is typically 4 °C warmer and salinity is 0.4 greater than that of cold-core Kamchatka eddies in the same density range. Aleutian eddies drift at approximately 1.2 km d−1 and retain their distinctive warm and salty characteristics for at least 2 years. Selected westward pathways during 1990–2004 are identified. If the shorter northern route is followed, Aleutian eddies remain close to the stream and persist sufficiently long to carry warm and saline water directly to the Kamchatka Current. This was observed during 1994–1997 with substantial warming of the waters in the Kamchatka Current and upstream Oyashio. If the eddies take a more southern route they detach from the stream but can still contribute significant quantities of warm and saline water to the upstream Oyashio, as in 2004–2005. However, the eddies following this southern route may dissipate before reaching the western boundary current region. 相似文献
2.
Considerable variations in intermediate water characteristics were found in the upper Oyashio based on the oceanographic data from 1953 to 2007. The long-term temperature trend at the 26.75σ? isopycnal is 0.03°C/year. This temperature trend is considerably higher than that determined earlier for the Sea of Okhotsk intermediate water and much higher than the World Ocean temperature trend. The westward transport of warm and salty water of the Alaskan Stream is most likely to cause the changes in the Kamchatka Current and upper Oyashio. It is established that Aleutian mesoscale eddies move westward from the location of their formation south of the Blizhniy Strait and transport warm water (3.8–4.2°C) in their core (100–600 m, ～26.75σ?)). As the trajectory of eddies is quite stable, the westward flow of warm and salty intermediate waters considerably influences the upper Oyashio characteristics. 相似文献
3.
New oceanographic observations are used for studying the Kamchatka Current and the Alaskan Stream and its Aleutian eddies in 1990–2017. The Aleutian eddies are mesoscale anticyclonic eddies that are formed within the Alaskan Stream southward of the Aleutian Islands be tween 170° and 180° E and are moving to the southwest. The rapid freshening of the upper layer and the increase in tem-perature and salinity in the Kamchatka Current halocline are detected. In the upper layer of the Kamchatka Current, salinity decreased by 0.2 psu per 27 years. The most rapid variations in salinity and temperature have been observed in recent years. In the halocline (at the isopycnic of 26.75σθ) temperature rose by 1.4°C and salinity in creased by 0.15 psu. The maximum temperature of the warm intermediate layer in the Kamchatka Current exceeded 4°C for the first time. The most likely reason for the temperature and salinity increase in the halocline is the transport of warm and salt water by the Aleu-tian eddies. 相似文献
4.
D. S. Rodionov G. Klingelhoefer E. N. Evlanov M. Blumers B. Bernhardt J. Gironés J. Maul I. Fleischer O. F. Prilutskii A. F. Shlyk V. M. Linkin C. d’Uston 《Solar System Research》2010,44(5):362-370
Möessbauer spectroscopy is a powerful tool for the mineralogical analysis of Fe-bearing materials. The miniaturized Möessbauer spectrometer MIMOS II has already been working on the surface of Mars for 6 years as part of the NASA Mars Exploration Rovers mission. The improved version of the instrument is a component of the scientific payload of the Phobos-Grunt mission. The scientific objectives of the instrument are the following: to identify the iron-bearing phases, to determine the quantitative distribution of iron among these phases, and to determine the distribution of iron among its oxidation states. 相似文献
5.
The upper Oyashio intermediate water, one of the source waters for the Sea of Okhotsk intermediate water, is exhibiting a
warming trend. The historical data show that the upper Oyashio temperature increased by 2.4°C during 1953 to 2007 at the potential
density of 26.75 at depths of approximately 170 m. This rate of warming is much faster than that of the global ocean and the
Sea of Okhotsk. The upper Oyashio warming is likely linked to the penetration of warm water of the Alaskan Stream westward.
One mechanism of this warm Alaskan Stream water penetration is associated with large Aleutian eddies. 相似文献
6.
Melkumyan A. A. Belov A. V. Abunina M. A. Shlyk N. C. Abunin A. A. Oleneva V. A. Yanke V. G. 《Geomagnetism and Aeronomy》2022,62(3):159-177
Geomagnetism and Aeronomy - The Forbush decreases for the period from 1997 to 2020 were studied based on data from the database on Forbush effects and interplanetary disturbances created and... 相似文献
7.
Abunina M. A. Belov A. V. Shlyk N. S. Eroshenko E. A. Abunin A. A. Oleneva V. A. Pryamushkina I. I. Yanke V. G. 《Geomagnetism and Aeronomy》2021,61(5):678-687
Geomagnetism and Aeronomy - In this paper, we study the effect of magnetic clouds on variations in the cosmic ray density recorded by neutron monitors. The statistical patterns and characteristic... 相似文献
8.
The south-flowing waters of the Kamchatka and Oyashio currents are key components of the western subarctic Pacific gyre. The dissipation of tidal energy in shallow and coastal regions of these currents and the attendant mixing are the important processes that affect the upper layer temperature and salinity. Examples of the impact of tidal currents on water temperature and salinity are the persistent tide-driven mixing around the Kashevarov and Kruzenshtern banks. The Kruzenshtern Bank is a shallow submarine bank stretching along the eastern continental slope of the Kuril Islands with the minimum depth of 86 m. Surface drifters observations are used to determine the characteristics of tidal currents and the circulation over these banks. New software that allows more versatility in the harmonic analysis is used for drifter’s data. The two banks have similar features. The variations in current velocities are dominated by the diurnal signals. The K1 and O1 tidal ellipses over the banks are the largest and clockwise. The enhanced tidal currents suggest that the formation of cold and saline water in summer is due to mixing of water column over the banks with intermediate waters. Variations of tidal ellipses over the bank may explain the formation of polynya at the western end of the Kashevarov Bank. We found that the 18.6-year lunar nodal cycle is a significant characteristic of salinity variation at the temperature minimum in the eddies eastward of the Boussole Strait over the period 1990–2015. 相似文献
9.
The Alaskan Stream south of the Blizhnii Strait disintegrates into mesoscale Aleutian eddies, which provide a westward transport
of warm water to the Kamchatka Current and upper Oyashio Current areas. Oceanographic observations from 1949 to 2009 are indicative
of a substantial rise of temperature and salinity in the intermediate waters of the Aleutian and Kamchatka currents. A long-term
temperature trend in the Aleutian Current in the intermediate layer (at isopicnal of 26.75σθ) amounted to ΔT = 0.013°C/year. A positive salinity trend was about 0.0014 psu/year. The ocean upperlayer salinity decreased with a rate
of −0.0021 psu/year simultaneously with the increase in salinity of the intermediate layer. The decreased salinity of the
upper layer and its increase in the intermediate layer result in the intensified halocline. The radius of the Aleutian eddies
significantly increased (by 50–100%), which is equivalent, at least, to twofold increase in the volume of the water transported. 相似文献
10.
The problems of measuring the variations in the gravitational and inertial fields on Phobos related to librational oscillations,
tidal effects, and seismic impacts have been considered in the paper. It has been indicated that thermal equilibrium noise
in a mechanical oscillator, which forms the basis for a sensor, is responsible for the oscillator’s maximal sensitivity at
a level of 8 × 10−9 m/s2. The actual sensitivity of the designed three-dimensional seismogravimeter, which was estimated based on the calibration
results, is ∼2 × 10−8 m/s2. This makes it possible to measure the anticipated variations in the gravitational field and to obtain information about
the seismic noise level with a surface oscillation amplitude resolution at a level of 2.5 × 10−7 m at frequencies of 0.1 Hz to ∼10−10 m at frequencies higher than 5 Hz. 相似文献