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Considered are the peculiarities of fast ice formation in the Antarctic coastal waters. It is noted that the fine-crystalline ice with the chaotic orientation of crystals is mainly developed in the surface layers of the ice cover as well as the ice formed due to the infiltration of the sea water and its subsequent freezing in the lower layers of the snow cover. It is demonstrated that under the conditions of coastal Antarctic, the lamination of the structure during the period of ice cover formation and its subsequent development is the result of heavy precipitation in the form of snow and the formation of the large amount of snow sludge and crystals of intrawater ice (frazil ice) on the open water. The main distinctive feature of the Antarctic sea ice is its seasonal stratification with the formation of the surface layer of recrystallized ice and underlying destructive layers including the water interlayer in the ice column. The provision of the safety of overice movement of machinery requires the development of methods of continuous remote control of the snow-ice stratum of the fast ice. 相似文献
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K. I. Kusatov A. P. Ammosov Z. G. Kornilova R. N. Shpakova 《Russian Meteorology and Hydrology》2012,37(6):392-396
The analysis of ice jam formation processes of anthropogenic nature in the middle reach of the Lena River in 2001 and 2010 is carried out. Peculiarities of ice jam formation, springflood and inundation of villages in the Republic of Sakha (Yakut Republic) related to preventive actions are demonstrated. Intensity of variation of stages of spring ice jam flooding at the Lena River streamgage sites is considered. The degree of anthropogenic factor effect on ice jams through hydrological and hydromorphological processes is demonstrated. 相似文献
4.
L. S. Banshchikova 《Russian Meteorology and Hydrology》2008,33(9):600-604
A methodology of plotting of the water levels along a river and its using for (1) finding places where ice jamming is possible, (2) estimation of the maximum levels caused by jams, and (3) estimation of risks of flooding in ungauged river sections is presented. For the Northern Dvina River case study, isolines of the 2003 river flood levels are plotted for the entire river length and places of possible jams are defined by using the proposed approach. 相似文献
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V. G. Kalinin 《Russian Meteorology and Hydrology》2008,33(12):819-822
In this paper, ice jams were studied and systemized for the first time for the Votkinsk reservoir catchment. For this purpose, observational and pooling data were used. The cartographic and attributive databases of sites where the jams occur were created by using GIS-technologies what allows obtaining their exact georeferences. Performed analysis of the studied river sections allowed revealing the main reasons of jamming. 相似文献
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L. R. Lukin 《Russian Meteorology and Hydrology》2013,38(7):480-485
Considered is the theoretical mechanism of the formation of immovable ice cover along the coast (the fast ice) from the seasonal ice and the mechanism of its destruction. It is demonstrated that the process of formation and spread of the winter stable fast ice is determined by simultaneous impact of several factors: the morphometry of the coast and bottom, the width of the close ice, dynamic effects that shear stress forces of the flow and wind make on the ice, the duration of maintaining the condition of immobility and freezing (adhesion) of the ice, the thickness of adhered ice, and the intensity of thermal growth of ice from below. It is revealed that the permanent factor is the morphometry of coasts and the bottom while the other factors have temporal variability of various scales. 相似文献
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A. N. Chetyrbotskii 《Russian Meteorology and Hydrology》2010,35(3):211-217
The model is constructed based on the concepts of the character of thermal evolution of the sea ice cover thickness. The dynamics
of the ice thickness and that of the melt water forming in the ice cover are considered at the stage of melting. The space
limitation of the marine environment for the ice is taken into account both for the stage of the ice cover formation and for
the stage of its melting. The model is investigated analytically. The parametric identification of the model and the estimation
of its adequacy are performed based on sampling distributions of the ice cover thickness in the Sea of Japan. 相似文献
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Abstract A major surface feature of the Greenland Sea during winter is the frequent eastward extension of sea ice south of 75°N and an associated embayment to the north. These features are nominally connected with the East Greenland Current, and both the promontory and the embayment are readily apparent on climatic ice charts. However, there are significant changes in these features on time‐scales as short as a few days. Using a combination of satellite microwave images (SSM/I) of ice cover, meteorological data and in situ velocity, temperature and salinity records, we relate the ice distribution and its changes to the developing structure and circulation of the upper ocean during winter 1988–1989. Our measurements illustrate the preconditioning that leads to convective overturn, which in turn brings warmer water to the surface and results in the rapid disappearance of ice. In particular, the surface was cooled to the freezing point by early December and the salinity then increased through ice formation (about 0.016 m d‐1) and brine rejection. Once the vertical density gradient was sufficiently eroded, a period of high heat flux (>300 W m‐2) in late January provided enough buoyancy loss to convectively mix the upper water column to at least 200 m. We estimate vertical velocities at about 3 cm s‐1 downward during the initial sinking. The deepening of the thermocline raised surface temperatures by over 1°C resulting in nearly 1.5 × 105 km2 of ice‐melt within two days. Average rates of ice retreat are about 11 km d‐1 southwestward, generally consistent with a wind‐driven flow. Comparison of hydrographic surveys from before and after the overturning indicate the fresh water was advected out of the area, possibly to the south and east of our moorings. 相似文献
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A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity. 相似文献
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A. N. Chetyrbotskii 《Russian Meteorology and Hydrology》2007,32(1):43-49
A model of space-time dynamics of the sea ice cover in which individual ice floes undergo a successive change in size is considered. The formation and melting of ice floes, their aggregation, and the formation of hummocks are taken into account. A parametric model identification is done based on a sample of ice cover area and thickness distribution in the Japan Sea. 相似文献
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It is demonstrated that during the whole annual cycle of ice cover evolution in 2006–2007 in the eastern seas of the Russian
Arctic and in the Arctic basin, the factors whose effect led to the formation of an extremely large anomaly of ice conditions
in summer 2007 were revealed. By the end of summer, the ice melted on the huge water area of 3500000 km2. In September, the ice edge between the meridians of 150° E-170° W reached the parallel of 85° N. The estimates of the open
water area being formed due to the ice melting and its drifting edge shift are given. 相似文献
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针对冰盖的定向地球工程研究旨在增强冰盖稳定性和减缓冰盖物质流失,从源头上减少冰盖对海平面上升的贡献,有望为应对气候变化和保护海岸线争取几百年的时间。冰盖地球工程主要作用在冰底和冰架-海洋界面上,主要途径如下：(1)排干或冻结冰盖底部水来干燥冰床,增强冰盖底部摩擦力;(2)在海洋中建造人造岛来支撑漂浮的冰架;(3)在冰架前端建造水下隔离墙,阻止温暖的海水到达冰川底部以减缓其融化。冰盖地球工程包括数值模拟、方案设计、工程试验和政治法律等诸多方面的研究。国际上的研究团队正在开展数值模拟和方案设计方面的研究,工程试验和政治法律等方面的研究尚未起步。预计工程试验的难度阶梯很可能是从实验室试验开始,到小尺度的野外试验,接着到格陵兰冰盖的入海冰川,最后到南极冰盖的入海冰川。针对冰盖的定向地球工程研究很有可能成为21世纪全球变化领域新兴的研究方向。 相似文献
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Abstract The steady, coupled ice‐ocean circulation model of Willmott and Mysak (1989) for a meridional channel is applied to the Labrador Sea for the winter season. The model consists of a thermodynamic reduced‐gravity ocean combined with a variable thickness ice cover that is in thermal equilibrium. Upon specifying the forcing fields of surface air temperature, wind stress and water temperature along the open southern boundary, the winter climatological ice‐edge position, ice thickness, ocean circulation and temperature fields are determined in the channel domain. The sensitivity of the results to the various model parameters is examined. In particular, the optimum heat exchange coefficients for the interfaces of air‐water, ice‐water and air‐ice are found. The model ice‐edge position compares favourably with the 50% winter climatological ice concentration isoline obtained from an analysis of 32 years (1953–84) of sea‐ice concentration data. The simulations of the ocean temperature and ice thickness are also quite realistic according to the observed records available. The model is also applied to two specific winters (1981 and 1983) during which anomalous sea‐ice and weather conditions prevailed in the Labrador Sea. 相似文献
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A. P. Zhichkin 《Russian Meteorology and Hydrology》2012,37(9):624-630
Presented are the results of studying the regional peculiarities of climatic variations of spatiotemporal distribution of ice in the Barents Sea water area in 1977?C2010. Demonstrated is the dynamics of the interannual and seasonal variability of main elements of the ice regime (ice cover area, ice edge position, and ice period duration). Revealed are the common features and differences in the ice conditions in the water areas under study. It has been found that there is a significant feedback between the specific ice coverage in different areas of the sea. The climatic variations of the total ice coverage of the Barents Sea for the period of 1960?C2010 are analyzed using the electronic database on the Barents Sea ice coverage. It can be supposed that the current warm phase of climatic variations in the Barents Sea is coming to the end. 相似文献
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全球变暖的背景下,北极航线的常规通航甚至商业运营有望实现,而海雾会严重影响航道上船只的航行安全。海冰的存在使海气之间相互作用变得更为复杂,是研究北极海雾不可忽略的因素。船载观测发现,与中纬度常见平流冷却雾形成时气温下降速度往往超过海水降温速度不同,北极海雾发生时海冰的存在还会使海水降温速度超过空气降温速度。然而目前海冰分布是否会影响模式模拟海雾的准确性还不得而知,因此本文利用Polar WRF（Polar Weather Research and Forecasting）模式模拟了中国第七次北极考察中观测到的一次海雾过程,并进行海冰密集度敏感性试验。通过与船载观测和欧洲中期天气预报中心再分析数据比对发现,在低浮冰区内（海冰密集度小于50%）考虑海冰分布时可以更加准确地刻画潜热通量与水汽通量,模拟出与观测事实相符的表层空气降温与增湿过程以及相对湿度的变化,因此能够更好地刻画海雾的三维结构及其生消演变。 相似文献
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The effect of snow on Antarctic sea ice simulations in a coupled atmosphere-sea ice model 总被引：1，自引：0，他引：1
The effect of a snow cover on sea ice accretion and ablation is estimated based on the ‘zero-layer’ version sea ice model
of Semtner, and is examined using a coupled atmosphere-sea ice model including feedbacks and ice dynamics effects. When snow
is disregarded in the coupled model the averaged Antarctic sea ice becomes thicker. When only half of the snowfall predicted
by the atmospheric model is allowed to land on the ice surface sea ice gets thicker in most of the Weddell and Ross Seas but
thinner in East Antarctic in winter, with the average slightly thicker. When twice as much snowfall as predicted by the atmospheric
model is assumed to land on the ice surface sea ice also gets much thicker due to the large increase of snow-ice formation.
These results indicate the importance of the correct simulation of the snow cover over sea ice and snow-ice formation in the
Antarctic. Our results also illustrate the complex feedback effects of the snow cover in global climate models. In this study
we have also tested the use of a mean value of 0.16 Wm-1 K-1 instead of 0.31 for the thermal conductivity of snow in the coupled model, based on the most recent observations in the eastern
Antarctic and Bellingshausen and Amundsen Seas, and have found that the sea ice distribution changes greatly, with the ice
becoming much thinner by about 0.2 m in the Antarctic and about 0.4 m in the Arctic on average. This implies that the magnitude
of the thermal conductivity of snow is of considerable importance for the simulation of the sea ice distribution. An appropriate
value of the thermal conductivity of snow is as crucial as the depth of the snow layer and the snowfall rate in a sea ice
model. The coupled climate models require accurate values of the effective thermal conductivity of snow from observations
for validating the simulated sea ice distribution under the present climate conditions.
Received: 20 November 1997/Accepted: 27 July 1998 相似文献
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V. A. Buzin 《Russian Meteorology and Hydrology》2010,35(4):272-280
Regional peculiarities of ice dams’ formation process on large rivers of the north of the European territory of Russia are
considered. Methodology and methods of ice-clogging floods’ forecasting at stretches with the risk of ice dams of the Northern
Dvina, Sukhona, Vaga, Pechora, and Mezen’ rivers are described. Method of forecasting of the flood characteristic, which has
not been forecasted before at ice dams, the duration of high water levels’ stand, is proposed. The possibility to plan ice-dam
prevention activities on the base of hydrological forecasting is shown. 相似文献
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The analysis of the long-term variability and spatiotemporal conjugacy of formation processes of ice conditions in the water areas of the Laptev, East Siberian, and Chukchi seas is carried out on the basis of the available data on the ice cover conditions in the above seas. On the whole, the type of relationships between the ice processes in the system of East Arctic seas indicates the existence of certain mechanisms generating the wave processes in the climatic system of the Arctic Basin manifested in the phase opposition in the development of ice conditions on the western and eastern peripheries of the basin under consideration. The statistical analysis of series of the ice coverage of water areas under consideration demonstrated that the existence of the long-term trend of this characteristic in some seas has its spatiotemporal features: the probability of the trend existence increases from west to east (from the Laptev Sea to the Chukchi Sea) and the trends are of opposite signs. 相似文献
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K. P. Tyshko 《Russian Meteorology and Hydrology》2010,35(12):823-831
Main differences are considered in the formation of physical and mechanical ice properties in hummocky formations as compared
with level areas of the ice cover. The results of laboratory and field investigations demonstrate that these differences are
caused both by dynamometamorphic transformations of crystal ice structure as a result of the compression of ice fields before
the beginning of hummocky ice formation and in the process of consolidation of ice blocks within the ice hummocks formed during
the winter-spring period. 相似文献