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1.
Primary production of phytoplankton and ice and under-ice flora of the Kara Sea and regions thereof has been assessed using region-specific models and MODIS-Aqua satellite data for 2002–2015. Average annual primary production of phytoplankton calculated for the growing season (April–October) amounted to 165 mg С m–2 day–1. Annual primary production of phytoplankton was 35 g C/m2. Annual primary production of phytoplankton in the entire Kara Sea was 13 × 1012 g C. Annual primary production of ice and underice flora calculated using an integrated biophysical model was 1.7 × 1012 g C, or 12% of total primary production of the Kara Sea; the ice cover dynamics and published data were taken into account for the calculations. The results have been compared to earlier primary production estimates for the Kara Sea. The extent of the increase in sea productivity during warming of the Arctic and the decrease in ice cover area are discussed. 相似文献
2.
Seasonal variation of the integrated primary production (IPP) and surface chlorophyll (Chl0) in different regions of the Kara Sea was studied from satellite data obtained by the MODIS-Aqua colour scanner and averaged for 2003–2015. The minimum variation of Chl0 concentration during the growing season (from April to October) was 1.5 times in southwestern region and 2 times in the northern region of the sea. It was found that the Chl0 concentration increased slightly in all regions by the end of the growing season. The maximum IPP value recorded in June coincided with the peak level of photosynthetically active radiation (PAR) and maximum river discharge. The IPP value varied in a wider range compared with the Chl0 concentration. The ratio of the maximum and minimum monthly average IPP values varied from 8.9 times in Southwestern region to 11.7 times in the Northern region of the sea. The average increase in the Chl0 concentration was 1.7 times (from 0.78 mg/m3 in April to 1.29 mg/m3 in October). The IPP value varied by a factor of 10.7 (from 26 mg C/m2 per day in October to 279 mg C/m2 per day in June). The article also discusses the influence of water column stratification, the concentration of nutrients, the PAR level, and river discharge on the seasonal IPP dynamics in the Kara Sea. 相似文献
3.
A. B. Demidov S. A. Mosharov V. A. Artemyev A. N. Stupnikova U. V. Simakova S. V. Vazyulya 《Oceanology》2016,56(4):515-526
Primary production (PP) models of the Kara Sea are developed based on data collected on fall expeditions (September–October 1993, 2007, and 2011) and their precision assessment utilizes the dataset collected in September 2013. The algorithms for different model types (depth-integrated and depth-resolved) are compared. The depth-resolved model performs slightly better than the depth-integrated one (the rootmean- square-difference (RMSD) are 0.29 and 0.31, respectively). These algorithms utilize the daily assimilation number (DAN) and photosynthetic efficiency (ψ) as the model coefficients, and surface chlorophyll a (chl a) and photosynthetically active radiation (PAR) as input variables. These algorithms perform better than the models that use chl a alone. Our results suggest that an increase in the performance of the Kara Sea PP models depends on the input of the photophysiological characteristics of phytoplankton (DAN and ψ) and PAR. To a lesser extent, this concerns the advantages of the depth-resolved model over the depth-integrated one. The constructed region-specific Kara Sea PP models combined with satellite-derived chl a and PAR can be used to estimate annual values and long-term variation of PP in hydrologically and hydrochemically similar waters of the Arctic Ocean. 相似文献
4.
Oceanology - Studies of seasonal variability of the East Siberian Sea (ESS) water column primary production (IPP) and evaluation of its total annual value (PPtot) were performed using MODIS-Aqua... 相似文献
5.
A. A. Vetrov 《Oceanology》2008,48(1):33-42
New maps of the mean monthly distribution of chlorophyll and the primary production in the Kara Sea were compiled using joint processing of CZCS (1978–1986), SeaWiFS (1998–2005), and MODIS (2002–2006) satellite data and field measurements. The annual primary production of phytoplankton is estimated at 22.3 × 106 t of C per year or 70 mg of C/m2 per day. The results of the calculations of the organic carbon budget in the Kara Sea are presented. 相似文献
6.
We observed strong internal tidal waves in the Kara Gates Strait. Internal tides are superimposed over a system of mean currents from the Barents to the Kara Sea. Field studies of internal tides in the Kara Gates were performed in 1997, 2007, and 2015. In 2015, we analyzed data from towed CTD measurements, numerical model calculations, and satellite images in the region. An internal tidal wave with a period of 12.4 h is generated due to the interaction between the currents of the barotropic tide and the bottom relief on the slopes of a ridge that crosses the strait from Novaya Zemlya to the continent. The depths of the ridge crest are 30–40 m. A constant current of relatively warm water flows from the Barents to the Kara Sea. An internal wave propagates in both directions from the ridge. In the Barents Sea, internal waves are intensified by the current from the Barents to the Kara Sea. Internal bores followed by a packet of short-period internal waves are found in both directions from the strait. Satellite images show that short-period internal waves are generated after the internal bore. A hydraulic jump was found on the eastern side of the strait. Numerical modeling agrees with the experimental results. 相似文献
7.
Characteristics of short-period internal waves in the Kara Sea inferred from satellite SAR data 总被引：1，自引：0，他引：1
I. E. Kozlov V. N. Kudryavtsev E. V. Zubkova A. V. Zimin B. Chapron 《Izvestiya Atmospheric and Oceanic Physics》2015,51(9):1073-1087
In this paper we present the results of short-period internal wave (SIW) observations in the Kara Sea on the basis of satellite ENVISAT ASAR data between July and October 2007. Altogether, 248 internal wave (IW) packets and solitons are identified in 89 SAR images. Detailed spatial statistics of IW signatures and their properties in the Kara Sea is presented. The primary regions of IW activity are the areas near the Kara Gates Strait, the southeastern part of the Novaya Zemlya Trough, and in the vicinity of Cape Zhelaniya. We identify the regions where large IW packets are observed with wavelengths up to 2–3 km and the front length exceeding 200 km. The mean interpacket distance for observed IWs is about 20 km, but it may reach 50–60 km. Consequent IW packets are observed to travel up to 500 km from the presumed generation points. The results of satellite observations are compared with results of previous studies. 相似文献
8.
Results of optical studies of the Kara Sea waters are considered. The data of ship borne measurements are compared with satellite
observations. The maximum values of the beam attenuation coefficient, the chlorophyll, and the yellow substance fluorescence
were observed in the Ob gulf and in the coastal waters west of the Yamal Peninsula. The minimum values were observed in the
central and western parts of the Kara Sea. Frontal zones with sharp changes of the parameters involved were observed. The
distribution of the seawater’s optical characteristics was closely related to the hydrological structure of the Kara Sea’s
waters. The data of the shipborne measurements were consistent with the satellite observations. 相似文献
9.
Research was implemented from September 15 through October 4, 2011 in the Kara Sea along transects located southeastwards Novaya Zemlya, in the St. Anna Trough, the Yenisei River estuary, and the adjacent shelf. The concentration of chlorophyll a was the highest in the photic zone (0.05–2.30 mg/m3, on average, 0.80 ± 0.37 mg/m3). The maximal concentration of Chl a at most of the stations located in the water layer of 7–30 m. Integral primary production in the water column varied from 3.0 to 151.0 mg C/m2 per day, on average, 37.2 ± 36.6 mg C/m2 per day. The maximal rate of primary production at most of the stations has been observed for the surface layer of the water column. Within the upper mixed water layer, relative primary production was from 31 to 100% (on average, 77 ± 20%). The most productive zone was the waters along Yenisei transect. In the estuary and at the adjacent shelf, primary production was 50 mg C/m2 per day, exceeding the range observed for other areas by 1.5–2.0 times. The concentrations of silica and nitrogen together with light regime and water temperature were the major limiting factors affecting the primary production rate in the Kara Sea in autumn. 相似文献
10.
To estimate the response of the primary production to the climate warning, the trends of the production changes within 1998–2006 were considered in tests areas in the Barents, Kara, and Chukchi seas using satellite and field data. Both positive and negative trends were revealed with a general tendency to an increase in the primary production and in the extent of the organic carbon burial in the bottom sediments. 相似文献
11.
热带太平洋海温异常对北极海冰的可能影响 总被引：1，自引：1，他引：0
本文利用1950-2015年间Hadley环流中心海冰和海温资料及NCEP/NCAR再分析资料,研究了热带太平洋海温异常对北极海冰的可能影响,并从大气环流和净表面热通量两个角度探讨了可能的物理机制。结果表明,在ENSO事件发展年的夏、秋季节,EP型与CP型El Niño事件与北极海冰异常的联系无明显信号。而La Niña事件期间北极海冰出现显著异常,并且EP型与CP型La Niña之间存在明显差异。EP型La Niña发生时,北极地区巴伦支海、喀拉海关键区海冰异常减少,CP型La Niña事件则对应着东西伯利亚海、楚科奇海地区海冰异常增加。在EP型La Niña发展年的夏、秋季节,热带太平洋海温异常通过遥相关波列,使得巴伦支海、喀拉海海平面气压为负异常并与中纬度气压正异常共同构成类似AO正位相的结构,形成的风场异常有利于北大西洋暖水的输入,同时造成暖平流,偏高的水汽含量进一步加强了净表面热通量收入,使得巴伦支海、喀拉海海冰异常减少。而在CP型La Niña发展年的夏季,东西伯利亚海、楚科奇海关键区受其东侧气旋式环流的影响,以异常北风分量占主导,将海冰从极点附近由北向南输送到关键区,海冰异常增加,而净表面热通量的作用较小。 相似文献
12.
Oceanology - The benthic fauna of Oga Bay (Kara Sea, Novaya Zemlya archipelago) was studied in 2015–2016 during the R/V Akademik Mstislav Keldysh expeditions. Five grab stations at depths of... 相似文献
13.
A. A. Kucheiko A. Yu. Ivanov A. A. Davydov A. Yu. Antonyuk 《Izvestiya Atmospheric and Oceanic Physics》2016,52(9):1031-1040
This paper is devoted to the detection and identification of icebergs in the Russian Arctic Seas from the use of high- and medium-resolution radar and optical images from EROS-B, Radarsat-1, Radarsat-2, SPOT-4 and SPOT-5 Earth observation satellites. In July–September of 2011–2013, the SCANEX Research and Development Center, the Federal State Unitary Enterprise Atomflot, and other partner organizations provided operational satellite monitoring of icebergs in the Kara Sea and the Laptev Sea. More than 130 highly detailed optical and radar images were received and processed. The Vilkitsky Strait—one of the narrowest and most dangerous places within the Northern Sea Route—was chosen as an experimental polygon. As a result, iceberg location in the strait during the 2011–2013 navigation periods was analyzed, as were the iceberg size, area, drift direction, and height. 相似文献
14.
The primary production and fluxes of organic matter to the seabed and their variations were estimated in the Norwegian, Greenland,
Barents, Kara, Laptev, East Siberian, and Chukchi seas in 2003–2008 on the basis of satellite and field data. When counting
the open water area with the assumptions made for the assessment of the primary production in the regions hidden under clouds,
the reliable trends of its variability (increasing) were revealed only in the Greenland, Barents, and Kara seas. 相似文献
15.
Oceanology - The benthic fauna of Sedova Bay (Kara Sea, Novaya Zemlya Archipelago) was studied during two cruises of the R/V Academik Mstislav Keldysh in 2015–2016. Three macrobenthic... 相似文献
16.
E. G. Arashkevich M. V. Flint A. B. Nikishina A. F. Pasternak A. G. Timonin J. V. Vasilieva S. A. Mosharov K. A. Soloviev 《Oceanology》2010,50(5):780-792
The data for the present study were collected at 20 sampling stations in the Kara Sea along the transect from the Ob estuary
to the deep sea St. Anna Trough in September 2007. Based on the hydrophysical features, the distribution of the Chl a, and the primary production, we distinguished six habitats: the river, estuary, inner and outer shelf, continental slope,
and trough. The impact of the small-size (<0.5 mm) and large-size (>0.5 mm) fractions of the zooplankton on the phytoplankton’s
organic carbon in the different regions of the Kara Sea was estimated. The ingestion rate was assessed using the analysis
of the gut fluorescence content and the gut evacuation rate. The zooplankton grazed 1–2% of the phytoplankton biomass in the
river and estuary; 3.5% over the shelf; and 6 and 10% in the regions of the trough and slope, respectively. The grazing impact
of the small-sized zooplankton increased from the river zone to the deep regions (from 1 to 90%) along with their share in
the total zooplankton abundance (from 18 to 95%). From 72 to 86% of the primary production was grazed over the shelf and slope.
The primary production did not cover the feeding requirements of the zooplankton in the estuarine regions and St. Anna Trough
in the autumn. In the estuarine regions, the major portion of the organic matter settles on the bottom due to the strong inflow
of the allochthonous matter and the relatively low zooplankton grazing. 相似文献
17.
H.J. Hirche K.N. Kosobokova B. Gaye-Haake I. Harms B. Meon E.-M. Nthig 《Progress in Oceanography》2006,71(2-4):288
After a short introduction to the physical setting and the history of biological research the pelagic ecosystem of the Kara Sea is described. Main emphasis is on regional aspects of the plankton communities and their seasonal dynamics using mostly data collected between 1996 and 2001. In the zooplankton, for which most data were available, four regional aggregations were separated: (1) the rivers and estuaries of the Southern Kara Sea, (2) the south-western and (3) the central Kara Sea, and (4) the northern troughs and slope. The phytoplankton communities had a similar distribution. To provide components for detailed carbon budgets the regional dynamics of bacterial, phytoplankton and zooplankton biomass and production are described and carbon requirements of bacteria and zooplankton are estimated. For completeness a short literature review on higher trophic levels is included. Finally, recent observations of the pelago-benthic coupling are considered. Estimates of the carbon requirements from the plankton and benthos reveal a large underestimation of primary production, which to date, together with seasonal aspects, shows the largest gap in our knowledge. 相似文献
18.
The distribution of the suspended particulate matter concentration in the Kara Sea is analyzed based on ship and satellite
data. The statistical relationships between the suspended matter concentration and the optical characteristics were revealed.
Charts of the distribution of the suspended matter concentration in the Kara Sea were plotted, which confirmed that the application
of optical methods for analyzing the spatial distribution of the suspended matter is effective. The most turbid waters were
observed in the Ob Gulf, Yenisei Bay, the Baidaratskaya Gulf, and the adjacent regions. The smallest concentrations of suspended
matter were observed in the central and western parts of the Kara Sea. 相似文献
19.
Oceanology - Benthic fauna in Stepovoi Bay (Kara Sea, Novaya Zemlya) was studied during expeditions of the R/V Professor Shtokman in 2013–2014. Sampling was carried out at ten grab stations... 相似文献
20.
Nonlinear internal waves(NIWs) are ubiquitous around the Kara Sea, a part of the Arctic Ocean that is north of Siberia. Three hot spot sources for internal waves, one of which is the Kara Strait, have been identified based on Envisat ASAR. The generation and evolution of the NIWs through the interactions of the tide and topography across the strait is studied based on a nonhydrostatic numerical model. The model captures most wave characteristics shown by satellite data. A typical inter-packets distance on the Barents Sea side is about 25 km in summer, with a phase speed about 0.65 m/s. A northward background current may intensify the accumulation of energy during generation, but it has little influence on the other properties of the generated waves. The single internal solitary wave(ISW) structure is a special phenomenon that follows major wave trains, with a distance about 5–8 km. This wave is generated with the leading wave packets during the same tidal period. When a steady current toward the Kara Sea is included, the basic generation process is similar, but the waves toward the Kara Sea weaken and display an internal bore-like structure with smaller amplitude than in the control experiment. In winter, due to the growth of sea ice, stratification across the Kara Strait is mainly determined by the salinity, with an almost uniform temperature close to freezing. A pycnocline deepens near the middle of the water depth(Barents Sea side), and the NIWs process is not as important as the NIWs process in summer. There is no fission process during the simulation. 相似文献