共查询到20条相似文献，搜索用时 156 毫秒
1.
V. V. Tikhonov I. A. Repina M. D. Raev E. A. Sharkov D. A. Boyarskii N. Yu. Komarova 《Izvestiya Atmospheric and Oceanic Physics》2015,51(9):914-928
In this paper, a new algorithm for determining the concentration of the ice cover in Polar Regions by data of satellite microwave radiometry is considered. The technique of its construction is described in detail; it cardinally differs from the technique of creating present-day algorithms. The new algorithm demonstrates good results in determining the concentration of the ice cover in Polar Regions. The algorithm permits one not only to obtain maps of ice concentration, but also to determine areas of puddles covering the ice-cover surface in summer months. The algorithm is easy-to-use and requires no additional or fitting parameters. At the end of the work, advantages and disadvantages of the new algorithm are discussed. 相似文献
2.
A review of contemporary methods for determining integrated parameters of the water content in the atmosphere―atmospheric water-vapor content and cloud liquid-water content―is presented. Fields of these parameters can only be mapped spatially on the basis of using data of satellite measurements. The least errors of the retrieval of atmospheric water-vapor content and cloud liquid-water content is provided by methods based on using measurements of the satellite-borne scanning multichannel microwave radiometers over the ice-free ocean areas in the absence of precipitation. Most methods for retrieving the atmospheric water-vapor content and cloud liquid-water content from the data of microwave radiometers are based on results of numerical simulation of brightness temperatures of the upwelling microwave radiation of the ocean–atmosphere system. The evolution of satellite-borne microwave radiometers and methods for the retrieval of integrated parameters of water content is presented. 相似文献
3.
Kuzmin A. V. Ermakov D. M. Sadovskii I. N. Sterlyadkin V. V. Sharkov E. A. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(9):1222-1230
Izvestiya, Atmospheric and Oceanic Physics - The current state of microwave radiometry for remote sensing of the Earth is considered. There are currently some 30 satellite microwave radiometers... 相似文献
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A discussion of the influence of sea roughness and spatial atmospheric inhomogeneities on the precision of satellite microwave radiometric measurements of the atmospheric parameters is presented. The two-scale model for microwave radiation of the ruffled sea surface without foam and spray is confirmed by experimental measurements. Investigations of the brightness temperature fluctuations of the clear and cloudy atmosphere are made using aircraft experimental measurements at the wavelengths 0.8 and 1.35 cm. Calculations of the radiation averaged over a satellite antenna footprint are carried out on the basis of these results and of well-known results of optical and infrared measurements. It is shown that sea roughness and the nonuniformity of clouds may result in errors in the integrated atmosphere water vapor and cloud liquid water content determination by satellite two-wavelength (0.8 and 1.35 cm) radiometric measurements up to 30 and 70 percent, respectively. 相似文献
6.
Alekseeva T. A. Sokolova J. V. Tikhonov V. V. Smolyanitsky V. M. Afanasyeva E. V. Raev M. D. Sharkov E. A. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(12):1690-1704
Izvestiya, Atmospheric and Oceanic Physics - In the period of intense ice melting, algorithms retrieving sea-ice concentration from satellite microwave radiometry (SMR) data may fail to detect vast... 相似文献
7.
E. A. Sharkov G. A. Kim I. V. Pokrovskaya 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1084-1091
Energy features of the succession of interrelated tropical cyclones (plural cyclogenesis) in the oceans of the Southern Hemisphere
(the southern part of the Indian Ocean and the southwestern part of the Pacific Ocean) over February 2008 are comprehensively
analyzed on the basis of the method of combining different-scale data of the infrared and radio thermal satellite sounding.
The data of infrared thermal channels of the geostationary Meteosat-7 satellite and the results of reconstruction of integral
water vapor from data of the AMSR-E microwave complex of the Aqua satellite were used. The analysis showed that the region
where water vapor has an increased integral concentration is the most effective channel for pumping the latent heat energy
from the tropics into midlatitudes. Each cyclone captures this region from the tropical zone and retains it throughout the
entire stage of its own evolution with the aid of the jet spiral bridge. The quantitative estimates of the latent energy of
the central equatorial region of water vapor in the intratropical convergence zone (ITCZ) of the Indian and Pacific oceans
were a basically new result, as well as the detection of considerable time variations in the latent heat associated with the
ejection of coherent water-vapor regions into high latitudes by plural cyclogenesis. 相似文献
8.
The advent of precision microwave radiometry has placed a stringent requirement on the accuracy with which the dielectric constant of sea water must be known. To this end, measurements of the dielectric constant have been conducted atS -band andL -band with a quoted uncertainty of tenths of a percent. These and earlier results are critically examined, and expressions are developed which will yield computations of brightness temperature having an error of no more than 0.3 K for an undisturbed sea at frequencies lower thanX -band. At the higher microwave and millimeter wave frequencies, the accuracy is in question because of uncertainties in the relaxation time and the dielectric constant at infinite frequency. 相似文献
9.
This paper considers different types of the continental runoff distribution over the Kara Sea depending on hydrological and meteorological processes based on 1993–2014 expedition data of the Shirshov Institute of Oceanology. The results of calculating the relative contribution of fresh water from several sources (the Ob and Yenisei rivers and melted ice) using hydrochemical parameters are also given. 相似文献
10.
Microwave remote sensing has become the primary means for sea-ice research, and has been supported by a great deal of field experiments and theoretical studies regarding sea-ice microwave scattering. However, these studies have been barely carried in the Bohai Sea. The sea-ice microwave scattering mechanism was first developed for the thin sea ice with slight roughness in the Bohai Sea in the winter of 2012, and included the backscattering coefficients which were measured on the different conditions of three bands(L, C and X), two polarizations(HH and VV), and incident angles of 20° to 60°, using a ground-based scatterometer and the synchronous physical parameters of the sea-ice temperature, density, thickness, salinity, and so on. The theoretical model of the sea-ice electromagnetic scattering is obtained based on these physical parameters. The research regarding the sea-ice microwave scattering mechanism is carried out through two means, which includes the comparison between the field microwave scattering data and the simulation results of the theoretical model, as well as the feature analysis of the four components of the sea-ice electromagnetic scattering. It is revealed that the sea-ice microwave scattering data and the theoretical simulation results vary in the same trend with the incident angles. Also, there is a visible variant in the sensitivity of every component to the different bands.For example, the C and X bands are sensitive to the top surface, the X band is sensitive to the scatterers, and the L and C bands are sensitive to the bottom surface, and so on. It is suggested that the features of the sea-ice surfaces and scatterers can be retrieved by the further research in the future. This experiment can provide an experimental and theoretical foundation for research regarding the sea-ice microwave scattering characteristics in the Bohai Sea. 相似文献
11.
基于全球海洋及其上空大气中关于有机磷酸酯（OPEs）的数据,分析了目前OPEs在全球海洋及其上空大气的分布特征、影响因素以及当前研究存在的不足。总结发现,海水中的OPEs主要来自河流输送,且浓度分布特征表现为由近及远、由浅及深逐渐递减。磷酸三（2-氯乙基）酯（TCEP）、磷酸三（1-氯-2-丙基）酯（TCPP）和磷酸三（1,3-二氯异丙基）酯（TDCPP）三种卤化OPEs是海水中主要污染物;输入到海水中的OPEs经过颗粒沉降等作用沉积到海洋沉积物中,随之,沉积物中的OPEs可能反析出或直接累积,在海洋沉积物中形成一个大的OPEs储存库。分析北太平洋到北冰洋表层沉积物中OPEs的浓度发现,从白令海峡到北冰洋,随着纬度的增加OPEs的浓度也普遍增加,且相对于非卤化OPEs,卤化OPEs更易被运输到偏远海域。总有机碳（TOC）与大洋沉积物中OPEs的浓度无相关性,但与近海海洋沉积物中OPEs的浓度呈正相关,TCEP和磷酸三异丁酯（TiBP）为海洋沉积物中主要污染物;海洋上空大气与水体中的OPEs是不可分割的,海洋上空大气中的OPEs一部分通过大气沉降进入海水,一部分继续迁移到更偏远区域,气团来源是影响其分布的主要因素。对比OPEs在全球海洋上空大气中的浓度分布发现,南北半球并无明显差异,TCEP和TCPP是海洋上空大气中主要污染物。 相似文献
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为研究不同波浪环境下,水底浮泥层产生泥沙悬扬后其浓度的分布特性,使用浊度计测定浊度的方法确定水体中泥沙的浓度,并在水槽实验中改变水深、浮泥厚度及造波机的频率和振幅,观察水槽中悬浮泥沙浓度的变化情况,获得水深、波浪频率、波幅以及浮泥厚度对底床泥沙悬扬的影响,分析泥沙浓度的垂向分布特征等。实验结果显示,水深对底床泥沙悬扬的影响最为显著,其他实验参数的影响均不十分显著。同时,通过垂向输沙平衡的分析,得到一个可描述泥沙垂向浓度分布的理论公式,并利用水槽实验结果进行验证。对比结果显示,理论公式所得曲线与实验结果曲线变化趋势一致,部分工况下,理论值稍稍偏大。 相似文献
13.
Kadygrov E. N. Knyazev A. K. Shaposhnikov A. N. 《Izvestiya Atmospheric and Oceanic Physics》2022,58(3):284-294
Izvestiya, Atmospheric and Oceanic Physics - In this paper, we consider the peculiarities of using the microwave radiometry method for remote sensing of the thermal stratification of the high... 相似文献
14.
本文将TMI（Tropical Rainfall Measuring Mission （TRMM）Microwave Imager）和AMSR-E（Advanced Microwave Scanning Radiometer for the Earth Observing System）卫星观测的全球海表温度与Argo浮标观测的近海表温度进行了比较。并检验了影响海温变化的因素,包括风速、水汽含量、液态云和地理位置。结果显示,TMI、AMSR-E海表温度与Argo近海表温度均明显相关。在低风速时,TMI、AMSR-E海表温度整体比Argo近海表温度高。在低风速时,TMI比AMSR-E海表温度更接近Argo近海表温度,但TMI海表温度在高纬可能没有经过良好校正。温度差异显示,在低水汽含量时,TMI和AMSR-E海表温度显示出暖的差异,代表TMI和AMSR-E海表温度在高纬均没有经过良好校正。黑潮延伸区的海表温度变化要比海潮区明显。春季在黑潮延伸区,卫星观测的海表温度与Argo近海表温度差异较小。在低风速时,TMI和AMSR-E海表温度均经过了良好校正,而TMI比AMSR-E效果更好。 相似文献
15.
SARAL carried onboard a radar altimeter that provides very precise measurements of the sea surface height (SSH). Like other altimetric missions, SARAL carries a passive microwave radiometer (PMR) for wet tropospheric correction to SSH. In the present study, new algorithms are developed for the retrieval of cloud liquid water (CLW) and total precipitable water vapor (TPW) over the global oceans from PMR measurements of the brightness temperatures. A radiative transfer and genetic algorithm based retrieval scheme is proposed for the estimation of CLW and TPW from SARAL PMR. The comparisons of CLW from PMR with independent measurements from GPM-GMI and SSMIS within and outside ±40° latitudes show correlation (R) of 0.86 and 0.83, bias of 0.7 and ?3.61?mg/cm2, and root mean square error (RMSE) of 8.42 and 8.07?mg/cm2, respectively. Similarly, TPW from PMR with GPM-GMI and SSMIS show R of 0.99 and 0.98, bias of ?0.04 and ?0.03?g/cm2 and RMSE of 0.17 and 0.17?g/cm2, respectively. The retrieval accuracy of CLW and TPW from the new algorithms is compared with these parameters provided in the SARAL geophysical data records as finished products, which showed substantial improvement in the quality of the parameters from the new algorithm. 相似文献
16.
Chemical fluxes of Asian rivers into oceans bear different regional variations. Three zones are characteristic of distinct dissolved sediment loads and yields and ionic concentration.Rivers into oceans in China play an important role in Asia because of their different chemical fluxes, among which those draining the Loess Plateau have high ionic concentration, low water discharges and dissolved sediment loads and yields.Climate, vegetation, soil and strata lithology, chemical weathering intensity and tectonic activity dominate chemical fluxes of Asian rivers into oceans, and different factors have different effects on the chemical fluxes of separate regional rivers. Rising of the Tibet Plateau also exerts an important influence on chemical compositions of rivers originating from it. 相似文献
17.
《Marine Policy》2016
This paper evaluates the international agreements in place for the protection of the environment and the regulation of human activities taking place in world's oceans and seas. 500 multilateral agreements were reviewed against a framework of reference, grounded on the theoretical approaches of Adaptive Management and Transition Management. According to this framework, oceans complex systems management should: (1) consider the global oceans as a Social-Ecological System (SES); (2) aim to achieve or maintain their ecological resilience; and (3) implement iterative, learning-based management strategies, supported by science-based advice to policy and management. The results show that the present international legal framework for the global oceans does not require countries to adopt an adaptive, complex systems approach for global oceans ecological resilience. Instead, this study supports the perspective of a double fragmentation among international agreements. First, global agreements focus on issue-based objectives for determined human activities, ecological components or anthropogenic pressures. Second, regional agreements have a wider scope, but also a varying level of inclusion of ecological resilience considerations. There is the need to foster the inclusion of such an approach into existing and future international agreements and their implementation, including through soft-law, project-based initiatives at global and regional scales. 相似文献
18.
海面风场与3.2厘米微波散射特性的研究 总被引：1，自引：0，他引：1
海面风场遥感的基础工作之一是微波散射特性的研究。美国于一九七八年发射了一颗海洋卫星Seasat-A[3],卫星上载有微波散射计,它被用来遥感全球风场,其测量风速范围为3—25m/s,测风速的精度为±2m/s或±10%,海面上分辨率达50公里。在海洋卫星发射以前,他们对海面风速与海面微波散射特性之间的关系已作了充分的研究,这样才能判读星载或机载上所得到的遥感数据。国外在这方面做了大量的工作,积累了大量的数据。例如,美国学者格兰特和易普利将雷达散射计架在桥上俯视河水,找出了3.2厘米、1.25厘米、8.6毫米海面回波与风速的函数关系[1]。 相似文献
19.
南海礼乐盆地海底麻坑地貌及成因分析 总被引：1，自引：0，他引：1
本文基于高分辨率多波束测深和浅地层剖面数据,首次对南海礼乐盆地南部坳陷海底麻坑进行了系统的识别研究。共识别出各类麻坑81个,其中麻坑直径最大约2.4 km,坑深最大约157 m。麻坑种类多样:按平面形态主要分为圆形、椭圆形、拉长形和新月形麻坑;按组合方式分为孤立麻坑、链状麻坑和复合麻坑;按直径分为正常麻坑和大型麻坑。区域内发育多条大型海底峡谷,峡谷侵蚀引起两侧地层稳定性降低,气体储层遭受破坏,泄露的气体沿断层或气烟囱等喷发出海底形成麻坑。而因麻坑生成时剥蚀的沉积物质与周围水体混合并逐渐发展成浊流,在一定程度上促进海底峡谷向下延伸。研究区内单个麻坑的平面形态最初为圆形或椭圆形,之后由于重力流和峡谷侵蚀的影响,逐渐发展成拉长形或新月形,麻坑之间也会发生组合形成复合麻坑。链状麻坑与冲沟的形成联系密切,沿垂直于等深线方向展布的链状麻坑在重力流的冲刷下,发育成底部平坦的麻坑冲沟。对比分析全球其他海域麻坑,发现海底麻坑尺寸与水深关系密切,在深水区域更容易发育大型麻坑。 相似文献
20.
A nonlinear numerical model based on depth averaged equations and a relevant physical model have been investigated for the deformation of the water wave propagating over a submerged parabolic obstacle in the presence of uniform current. Physical and numerical modeling for wave with both following and opposing currents are done to explore the wave evolutions during passage over the submerged obstacle. A third-order Stokes dispersion relation is utilized in some cases in the computation. Separated flow zone is taken into consideration by two empirical equations obtained from the physical model testing done by the authors. Verification and validation of the numerical model by other published theoretical and experimental data are presented. 相似文献