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1.
I. N. Mordvintsev N. G. Platonov I. V. Alpatsky 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1127-1134
The main results of processing the long-term satellite data in different spectral ranges and with different spatial resolutions
used to map Arctic sea ice parameters are presented. The advantages of the methods developed in order to estimate these parameters
on the basis of microwave sensor measurements are indicated. The specific features of the long-term dynamics of the main sea
ice geophysical parameters (the sea ice area and distribution during the summer minimum, ice age structure and thickness,
multiyear ice concentration, times of ice melt and freeze onset, etc.) are presented. The effect of changes in sheet ice on
the status of large Arctic mammals is estimated. 相似文献
2.
A classification of sea ice in the Arctic by age (multiyear; first-year; and first-year deformed ice, nilas, etc.) is developed based on the Bayesian approach using satellite radar data and taking into account regional peculiarities of these types of ice for different sectors of the Arctic. Estimations of a priori probabilities for each ice type, which are required for the use of the Bayesian classification, are obtained by the analysis of ice charts in the Arctic seas developed at the AARI in 2008–2013 using satellite data. A posterior probabilities are estimated visually by an expert. Types of sea ice distinguished by the expert on satellite images make it possible to create sample values of the radar-scattering cross section (RSCS). Examples of the proposed Bayesian classification of ice in the Laptev Sea according to Envisat satellite data are given. 相似文献
3.
北极海冰输出研究综述 总被引：1，自引：1，他引：0
北极海冰对全球气候变化起重要的指示作用。除了海水冻结和融化过程以外,通过弗拉姆海峡(Fram Strait)的海冰输出也是影响北极海冰质量变化的重要动力机制。观测数据中的多源卫星遥感数据(尤其是辐射计观测数据)在获取大尺度连续观测方面具有独特的优势,在研究北极海冰输出面积通量变化方面有着广泛应用。本文总结了北极弗拉姆海峡、其他通道(S-FJL、FJL-SZ、加拿大群岛、Nares海峡通道)海冰输出面积或体积通量,着重介绍了弗拉姆海峡不同年龄海冰输出情况,并总结和分析了影响北极海冰输运的大尺度大气活动模态。最后,本文阐明北极海冰输出方面现有研究的不足之处以及未来的突破方向。 相似文献
4.
本文系统地评估了国家海洋环境预报中心于我国第七次北极科学考察期间开展的北极海冰密集度数值预报结果。该预报系统基于麻省理工大学通用环流模式,并采用牛顿松弛逼近（Nudging）资料同化方法,计算输出未来1~5 d的北极海冰密集度预报产品。本文将数值预报结果同卫星观测的海冰密集度、再分析资料和"雪龙"号第七次北极考察期间观测的海冰密集度数据进行了对比分析。结果表明,预报的北极海冰密集度小于卫星观测值,24 h、72 h和120 h预报结果的偏差分别为-2.7%、-3.1%和-3.2%;数值产品的预报技巧好于气候态结果和惯性预报,但是在海冰出现快速融化或冻结时,基于Nudging同化的数值预报技巧仍有不足。另外,相比船测数据,数值预报结果在海冰边缘区的偏差相对较大,24 h、72 h和120 h预报结果的偏差分别为8.8%、12.0%和14.5%。 相似文献
5.
地球系统模式FIO-ESM对北极海冰的模拟和预估 总被引：5，自引：3，他引：2
评估了地球系统模式FIO-ESM(First Institute of Oceanography-Earth System Model)基于CMIP5(Coupled Model Intercomparison Project Phase 5)的历史实验对北极海冰的模拟能力,分析了该模式基于CMIP5未来情景实验在不同典型浓度路径(RCPs,Representative Concentration Pathways)下对北极海冰的预估情况。通过与卫星观测的海冰覆盖范围资料相比,该模式能够很好地模拟出多年平均海冰覆盖范围的季节变化特征,模拟的气候态月平均海冰覆盖范围均在卫星观测值±15%范围以内。FIO-ESM能够较好地模拟1979-2005年期间北极海冰的衰减趋势,模拟衰减速度为每年减少2.24×104 km2,但仍小于观测衰减速度(每年减少4.72×104 km2)。特别值得注意的是:不同于其他模式所预估的海冰一直衰减,FIO-ESM对21世纪北极海冰预估在不同情景下呈现不同的变化趋势,在RCP2.6和RCP4.5情景下,北极海冰总体呈增加趋势,在RCP6情景下,北极海冰基本维持不变,而在RCP8.5情景下,北极海冰呈现继续衰减趋势。 相似文献
6.
N. G. Platonov I. N. Mordvintsev V. V. Rozhnov I. V. Alpatsky 《Izvestiya Atmospheric and Oceanic Physics》2012,48(9):1027-1038
The summer minimum of the Arctic sea ice area and extent have been estimated for 2011 using satellite passive microwave data. Compared with sea ice conditions during the satellite era (1979 to the present), the Arctic ice cap is close in size to the absolute minimum recorded in 2007. However, the spatial distribution of sea ice at the end of summer differed in 2007 and 2011 due to the atmospheric circulation effect on the position of the ice edge. It is shown that the decreasing rate of the ice cover has increased fourfold since 2003. A linear model has been developed for the global short-term prediction of Arctic ice conditions and historical reconstruction (until the middle of the 20th century, including the pre-satellite era) of summer ice conditions from the air temperature fields using the dimensionality reduction technique (principal component analysis) and canonical correlation analysis. The simulation results confirm the drastic change in the sea ice area at the end of summer after 2002. 相似文献
7.
对地球系统模式FIO-ESM同化实验中北极海冰模拟的评估 总被引：3，自引：0，他引：3
本文评估了地球系统模式FIO-ESM(First Institute of Oceanography-Earth System Model)基于集合调整Kalman滤波同化实验对1992-2013年北极海冰的模拟能力。结果显示:尽管同化资料只包括了全球海表温度和全球海面高度异常两类数据,而并没有对海冰进行同化,但实验结果能很好地模拟出与观测相符的北极海冰基本态和长期变化趋势,卫星观测和FIO-ESM同化实验所得的北极海冰覆盖范围在1992-2013年间的线性变化趋势分别为-7.06×105和-6.44×105 km2/(10a),同化所得的逐月海冰覆盖范围异常和卫星观测之间的相关系数为0.78。与FIO-ESM参加CMIP5(Coupled Model Intercomparison Project Phase 5)实验结果相比,该同化结果所模拟的北极海冰覆盖范围的长期变化趋势和海冰密集度的空间变化趋势均与卫星观测更加吻合,这说明该同化可为利用FIO-ESM开展北极短期气候预测提供较好的预测初始场。 相似文献
8.
9.
The effects of resolving the Canadian Arctic Archipelago in a finite element sea ice model 总被引：1，自引：0，他引：1
Though narrow straits may have a strong influence on the large-scale sea ice mass balance, they are often crudely represented in coarse resolution sea ice models. Unstructured meshes, with their natural ability to fit boundaries and locally increase the mesh resolution, propose an alternative framework to capture the complex oceanic areas formed by coasts and islands. In this paper, we develop a finite element sea ice model to investigate the sensitivity of the Arctic sea ice cover features to the resolution of the narrow straits constituting the Canadian Arctic Archipelago. The model is a two-level dynamic-thermodynamic sea ice model, including a viscous-plastic rheology. It is run over 1979–2005, forced by daily NCEP/NCAR reanalysis data. Confronting qualitatively numerical experiments with observations shows a good agreement with satellite and buoys measurements. Due to its simple representation of the oceanic interactions, the model overestimates the sea ice extent during winter in the southernmost parts of the Arctic, while the Baffin Bay and Kara Sea remain ice-covered during summer. In order to isolate the benefits from resolving the Canadian Arctic Archipelago, a numerical experiment is performed where we artificially close the archipelago. Focusing on the large-scale sea ice thickness pattern, no significant change is found in our model, except in the close surroundings of the archipelago. However, the local and short-term influences of the ice exchanges are nonnegligible. In particular, we show that the ice volume associated to the Canadian Arctic Archipelago represents 10% of the Northern Hemisphere sea ice volume and that the annual mean ice export towards Baffin Bay amounts to 125 km3 yr−1, which may play an important role on the convective overturning in the Labrador Sea. 相似文献
10.
AbstractSea ice type is one of the most sensitive variables in Arctic sea ice monitoring, and it is important for the retrieval of ice thickness. In this study, we analyzed various waveform features that characterize the echo waveform shape and Sigma0 (i.e., backscatter coefficient) of CryoSat-2 synthetic aperture radar altimeter data over different sea ice types. Arctic and Antarctic Research Institute operational ice charts were input as reference. An object-based random forest (ORF) classification method is proposed with overall classification accuracy of 90.1%. Accuracy of 92.7% was achieved for first-year ice (FYI), which is the domain ice type in the Arctic. Accuracy of 76.7% was achieved at the border of FYI and multiyear ice (MYI), which is better than current state-of-the-art methods. Accuracy of 83.8% was achieved for MYI. Results showed the overall accuracy of the ORF method was increased by ～8% in comparison with other methods, and the classification accuracy at the border of FYI and MYI was increased by ～10.5%. Nevertheless, ORF classification performance might be influenced by the selected waveform features, snow loading, and the ability to distinguish sea ice from leads. 相似文献
11.
北极海冰正处于快速减退时期,北极海冰体积变化是全球气候变化的重要指示因子。本文利用两种卫星高度计数据（ICESat和CryoSat-2）反演得到的海冰厚度数据,结合星载辐射计提取的海冰密集度数据以及海冰年龄数据,估算了近期的北极海冰体积以及一年冰和多年冰体积变化。CryoSat-2观测时段（2011-2013年）与ICESat观测时段（2003-2008年）相比,北极海冰体积在秋季（10-11月）和冬季（2-3月）分别减少了1 426 km3和412 km3。其中,秋季和冬季的一年冰的体积增加了702 km3和2 975 km3。相反,多年冰分别减少了2 108 km3和3 206 km3。多年冰的大量流失是造成北极海冰净储量下降的主要原因。 相似文献
12.
基于海冰密集度的消退起始时间判别方法改进研究与应用 总被引：1，自引：1，他引：0
海冰融化过程以正反馈的形式影响着海洋的热量吸收,对北极生态环境的变化和经济活动的开展起着重要作用。基于1979–2018年北冰洋逐日海冰密集度数据,本文综合考虑不同海域海冰冰况等因素,对北冰洋边缘海海冰消退起始时间的判别方法进行了改进。通过不同的方案对比分析表明,改进后的方法能够反映不同海域、不同年份冰情的变化;并且可消除一些天气扰动现象的干扰,避免过早地判别消退起始时间。应用本方法分析发现北冰洋各边缘海消退起始时间存在提前的趋势,与融化起始时间的提前趋势较为一致。但是不同海域提前程度存在明显差异,喀拉海和楚科奇海提前消退的趋势最强,达到了9 d/(10 a),而东西伯利亚海消退提前趋势最弱,只有4 d/(10 a),区域间的差异逐渐增大。海冰消退起始时间存在显著的年际差异,各边缘海的标准差均在15 d左右,近10年中消退最早与最晚之间的差值最大可达50 d,出现在波弗特海。 相似文献
13.
本文通过对2001—2017年秋季北极低云的多源数据的分析,展示了本世纪以来北极秋季低云的变化,并为其变化提供了一个新的可能的解释。卫星和再分析数据表明,秋季北极有冰海面低云存在减少的趋势,且在北极边缘海区表现为950 hPa(约500 m)以下近地面云显著减少。本文研究表明,在有冰海面上,低云减少的趋势与背景大气增暖导致的大气相对湿度降低有关,这一关系在80°N以北的北极中央区更明显。而在北极边缘海区,气旋活动对云的影响更重要。在有冰海面,气旋与低云的长期变化趋势相反,两者的年际变化呈负相关关系。利用自组织映射(SOM,Self-Organizing Map)对所有气旋日垂直运动和云分布进行了初步分析,结果表明:在无冰海面和有冰海面由于气旋垂直运动及背景(无气旋日)云分布的差异,气旋对云的影响存在差异。气旋在有冰海面导致低云减少为主,而在无冰海面导致低云增加为主。 相似文献
14.
北冰洋航路是未来全球航运的重点开拓领域,海冰运动对北冰洋航路开发有重要影响。本文利用风云三号卫星中分辨率光谱成像仪(FY-3/MERSI)数据的特点和优势,研究北冰洋流冰自动提取和运动跟踪的方法。首先在分析流冰灰度分布特征的基础上,提出分区域阈值分割与梯度差分相结合的方法实现块状流冰提取,然后根据块状流冰的多种几何特征匹配同名流冰并计算其运动速度。应用这种方法跟踪2011年6月弗雷姆海峡流冰运动,跟踪结果与美国国家冰雪数据中心提供的极地网格化日均海冰运动矢量整体趋势一致,验证了方法的有效性。这种方法获取各块流冰实际运动速度,可以有效弥补网格化海冰运动平均速度场分布和细节的不足,为北冰洋航路开发提供更详细的流冰运动信息。 相似文献
15.
16.
本文利用1951?2021年哈德莱中心提供的海冰和海温最新资料以及美国国家海洋和大气管理局气候预报中心提供的NCEP/NCAR再分析资料,分析探讨了北极海冰70余年的长期变化特征,进而研究了其快速减少与热带海温场异常变化之间的联系,揭示了在全球热带海洋海温场变化与北极海冰之间存在密切联系的事实。结果表明,北极海冰异常变化最显著区域出现在格陵兰海、卡拉海和巴伦支海。热带不同海区对北极海冰的影响存在明显时滞时间和强度差异,热带大西洋的影响相比偏早,印度洋次之,太平洋偏晚。热带大西洋、印度洋和中东太平洋海温异常影响北极海冰的最佳时间分别是后者滞后26个月、30个月和34个月,全球热带海洋影响北极海冰的时滞时间为33个月。印度洋SST对北极海冰的影响程度最强,其次是太平洋,最弱是大西洋。全球热带海洋对北极海冰的影响过程中,热带东太平洋和印度洋起主导作用。当全球热带海洋SST出现正（负）距平时,北极海冰会出现偏少（多）的趋势,而AO、PNA、NAO对北极海冰变化起重要作用,是热带海洋与北极海冰相系数的重要“纽带”。而AO、PNA和NAO不仅受热带海洋SST的影响,同时也受太平洋年代际振荡PDO和大西洋多年代际AMO的影响,这一研究为未来北极海冰快速减少和全球气候变暖机理的深入研究提供理论支撑。 相似文献
17.
太平洋夏季水对加拿大海盆海冰的影响 总被引：1，自引：0，他引：1
近年来,北极海冰发生了大面积减少,减少的原因仍存在着争议。基于2003-2011年的水文和遥感卫星数据,对北冰洋加拿大海盆的太平洋水和海冰进行研究。通过对比2006年和2007年太平洋水位温与海冰密集度的空间分布,发现太平洋水暖异常于2007年1-3月进入加拿大海盆的中部,并可能导致了2007年夏季海冰大面积的融化。2003-2011年,在加拿大海盆的中部,太平洋水位温与海冰密集度存在着时间上的负相关。选取2007年8月,发现两者在空间上也存在着负相关。这很可能说明太平洋水暖异常在流动的过程中,向上输送了热量,在一定程度上,融化了海冰,从而触发海冰-反照率正反馈,导致海冰的减少。因此,通过白令海峡进入北冰洋的太平洋夏季水,对北极海冰面积的减少有着重要影响。 相似文献
18.
V. G. Bondur 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1007-1018
The urgency and specific features of the application of the up-to-date aerospace methods and technologies in order to monitor
different oil and gas facilities; study subsurface geology of oil and gas areas; search for oil and gas deposits (particularly
in Arctic regions); control oil, gas, and product pipelines; and estimate the environmental conditions in the areas of hydrocarbon
production and transportation on land and on the sea are justified and analyzed. The problems in the oil and gas industry
which can be solved using aerospace data are systematized. The principles of organization of aerospace monitoring and the
physical bases of remote sensing methods for solving different problems in the oil and gas industry are considered. The application
of aerospace methods and technologies in order to monitor the environmental conditions in the oil and gas production areas,
monitor pipelines, detect pollution of the marine environment with oil products (particularly, after the accident on the oil
platform in the Gulf of Mexico in 2010), and control the ice conditions in the Arctic oil and gas areas is illustrated. 相似文献
19.
Quantifying the contribution of natural variability to September Arctic sea ice decline 总被引：1，自引：0，他引：1
Arctic sea ice extent has been declining in recent decades. There is ongoing debate on the contribution of natural internal variability to recent and future Arctic sea ice changes. In this study, we contrast the trends in the forced and unforced simulations of carefully selected global climate models with the extended observed Arctic sea ice records. The results suggest that the natural variability explains no more than 42.3% of the observed September sea ice extent trend during 35 a(1979–2013) satellite observations, which is comparable to the results of the observed sea ice record extended back to 1953(61 a, less than 48.5% natural variability). This reinforces the evidence that anthropogenic forcing plays a substantial role in the observed decline of September Arctic sea ice in recent decades. The magnitude of both positive and negative trends induced by the natural variability in the unforced simulations is slightly enlarged in the context of increasing greenhouse gases in the 21st century.However, the ratio between the realizations of positive and negative trends change has remained steady, which enforces the standpoint that external forcing will remain the principal determiner of the decreasing Arctic sea ice extent trend in the future. 相似文献
20.
Land, marine, and satellite observations have been used to study changes in methane concentrations in the lower atmosphere during the warm months of the year (July through October) in Arctic regions having different potentials for methane production. The Atmospheric Infrared Sounder (AIRS) data for 2002–2013 are used to explore the interplay between local methane sources in the terrestrial region of the Eurasian Arctic and on the Arctic shelf over the warm period of the year. Linear trends in atmospheric methane concentrations over different Arctic regions are calculated, and a hypothesis of the relation of concentration variations to climatic parameters is tested. The combination of land, marine, and satellite observation is used to develop a conceptual model of the atmospheric methane field in the terrestrial part of the Russian Arctic and on the Arctic shelf. It is shown that the modern methane growth rate in the Arctic does not exceed the Northern Hemisphere mean. It is concluded that the methane emission in the Arctic has little effect on global climate compared to other factors. 相似文献