共查询到20条相似文献，搜索用时 250 毫秒
1.
M. B. Gokhberg V. M. Lapshin G. M. Steblov S. L. Shalimov 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1019-1027
The effects that the two Kuril undersea earthquakes of November 15, 2006, and January 13, 2007, had on the ionosphere are
considered on the basis of the results of measurements of variations in the ionosphere’s total electron content obtained from
the network of Russian GPS stations. Owing to a favorable location of the stations, the ionosphere’s response to these earthquakes
is studied in the vicinity of and far (up to distances on the order of 1000 km) from their epicenters. It is found that the
apparent velocity of propagation of ionospheric disturbances (1–3 km/s) significantly exceeds the velocity of propagation
of tsunami waves caused by earthquakes; this fact can be used in forecasting tsunamis. It is shown that, in parallel with
the known type of ionospheric response to earthquakes in the form of an N-wave, there is also its response in the form of an inverted N-wave in the vicinity of and far from their epicenters. The causes of occurrence of the response in the form of an inverted
N-wave are interpreted. 相似文献
2.
应用1985—2002年夏季欧洲中期天气预报中心(ECMWF)的40a再分析资料,初步分析了副热带西北太平洋区域温带气旋、热带气旋和高空冷涡三种涡旋的三维结构及其时空分布特征。结果指出:(1)不同种类的涡旋具有不同的三维结构特征;(2)温带气旋和热带气旋主要分布在400hPa以下,涡旋分布的高值区位于近海海区,向内陆方向或向远海方向分布减少。副热带高空冷涡分布在太平洋上空的400~100hPa,呈东西向带状分布;(3)三种涡旋的个体强度有不同的年际变化特征。 相似文献
3.
Izvestiya, Atmospheric and Oceanic Physics - International investigations into the correlation between tropical cyclones (TCs) and the ionosphere are associated with great difficulties in proving... 相似文献
4.
G. D. Aburjania 《Izvestiya Atmospheric and Oceanic Physics》2011,47(4):491-502
The generation and further linear and nonlinear dynamics of planetary magnetized Rossby waves (MRWs) in the rotating dissipative ionosphere are studied in the presence of a zonal wind (shear flow). MRWs are caused by interaction with the spatially nonuniform geomagnetic field and are ionospheric manifestations of ordinary tropospheric Rossby waves. A simplified self-consistent set of model equations describing MRW-shear flow interaction is derived on the basis of complete equations of ionospheric magnetohydrodynamics. Based on an analysis of an exact analytical solution to the derived dynamic equations, an effective linear mechanism of MRW amplification in the interaction with nonuniform zonal wind is ascertained. It is shown that operators of linear problems are non-self-adjoint in the case of shear flows, and the corresponding eigenfunctions are nonorthogonal; therefore, the canonically modal approach is of little use when studying such flows; a so-called nonmodal mathematical analysis is required. It is ascertained that MRWs effectively get shear flow energy during the linear stage of evolution and significantly increase (by several orders of magnitude) their energy and amplitude. The necessary and sufficient condition of shear flow instability in an ionospheric medium is derived. Nonlinear self-localization begins with the development of shear instability and an increase in the amplitude, and the process ends with the self-organization of strongly localized isolated large-scale nonlinear vortex structures. Thus, a new degree of freedom and a way for perturbation evolution to occur appear in medium with shear flow. The nonlinear systems can be a pure monopole vortex, a vortex streets, or vortex chains depending of the shape of the sheared flow velocity profile. The accumulation of such vortices in the ionospheric medium can produce a strongly turbulent state. 相似文献
5.
Effect of mesoscale atmospheric vortex processes on the upper atmosphere and ionosphere of the Earth
The mechanisms of incipience and intensification of dangerous atmospheric vortex processes such as tropical cyclones (TCs) and their interaction with the Earth’s ionosphere are considered. Different models of TCs are analyzed, including models taking into account the ionization processes. The mechanisms taking into account the spiral field of velocities during TC formation are analyzed, as are the physical mechanism that explains the statistical correlation between short-term variations in galactic cosmic rays (Forbush decreases) and the frequency of incipience and the intensification of TCs. It is shown that such an effect is conditioned by a decrease in the ion-production rate during Forbush decreases against the tropopause and, hence, a decrease in the temperature upon the top of the ionosphere altitude because of a decrease in the latent heat release due to water-vapor condensation on the newly formed ions. This process leads to an increase in the temperature difference between the ocean surface and the top level of TCs and, respectively, to the intensification of vertical convection, which results in cyclone intensification. It is concluded that the study of these mesoscale vortex processes requires taking into account not only the hydrodynamical features of these formations, but also their thermodynamical and electrodynamical properties. The results are important for the organization of studying and monitoring TCs with the use of spaceborne techniques. 相似文献
6.
近58a来影响和登陆浙江的热带气旋统计特征分析 总被引：3，自引：0，他引：3
本文利用1949-2006年热带气旋资料,对58a来影响和登陆浙江热带气旋的登陆位置、登陆时间的年际、月际和日变化、登陆后的移速及路径变化与降水中心分布的关系、登陆后维持和衰减情况等进行了统计分析.统计结果表明：影响和登陆浙江的热带气旋有较明显的年际、月际和日变化特征;登陆浙江的热带气旋陆上维持时间与登陆时的强度正相关,登陆后12h内热带气旋衰减较快;登陆后移向偏北分量大的或移速加快的热带气旋,主要降水区出现在路径右侧的可能性大. 相似文献
7.
8.
香港经常受到西北太平洋热带气旋的影响,对该地区热带气旋持续时间的研究有助于经济社会的稳定发展。按照气象和天文台警告信号,热带气旋分为不同的强度等级。建立热带气旋持续时间的Poisson-Weibull复合分布模型,相应获得持续时间重现值的求解公式,分别用于不同热带气旋分类下持续时间多年一遇重现值的计算中。基于1987-2016年袭港热带气旋数据的分析结果表明,Poisson-Weibull分布适用于不同的持续时间分类样本;强的热带气旋经常会伴随较长的持续时间,这将会对该地区造成更为严重的破坏,这可为防灾减灾提供参考。 相似文献
9.
Physical causes controlling the influence of the main cosmic factors on the state of the ionosphere and, further, on weather
and climatic phenomena, including the global warming, are investigated. These investigations are based on the Rydberg excitation
of the experimentally observed microwave radiation of the Earth’s ionosphere by energetic ionospheric electrons. This microwave
radiation virtually freely penetrates into the lower atmosphere, providing channels for the influence of solar variability
on terrestrial phenomena. The factors causing an anomalous wear of Russian pipeline systems are also analyzed, and the methods
for reducing their rapid corrosion through taking into account the influence of heliogeomagnetic and ionospheric disturbances
are described. Such investigations are supported by the space experiment on permanent monitoring of the factors controlling
heliogeomagnetic activity, i.e., fluxes of ionizing radiation of the Sun and fluxes of electrons precipitating from the radiation
belts. 相似文献
10.
采用1979—2019年热带气旋最佳路径资料,分析影响中国沿海的热带气旋的时空演变特征,并结合Ni?o3.4指数、海表温度和海洋上层热容量资料,对热带气旋与ENSO变化关系进行初步探讨。结果表明,近40年来影响中国沿海的热带气旋经历了1990年代减弱,2000年代增强的变化过程,且在2000年以后呈现显著向岸迁移趋势。影响中国沿海的热带气旋与表征ENSO的Ni?o3.4指数的相关关系在2000年发生突变,具体表现为ACE与Ni?o3.4指数在2000年前呈显著正相关,2000年后二者相关性明显下降。通过将ACE分解成平均强度ACE1、持续时间ACE2和频数ACE3这三个分量,发现2000年前Ni?o3.4指数与平均强度ACE1呈显著正相关,但2000年后Ni?o3.4指数与ACE1相关关系减弱,这可能是导致ACE与Ni?o3.4指数的相关关系在2000年左右发生突变的主要原因。持续时间ACE2与Ni?o3.4指数一直保持显著正相关,频数ACE3<... 相似文献
11.
Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming 总被引：1，自引：1，他引：1
1 IntroductionAs is well known, the increasing greenhousegas and SO2extricated into the atmosphere due to hu-man activities have alreadyresulted in the global sur-face air temperature (SAT) and sea surface temper-ature (SST) rising. The globally mean surf… 相似文献
12.
We statistically study diurnal variations in the maximum wind velocity in tropical cyclones on the basis of vast experimental material. We have found notable oscillations in the acceleration of rotation velocity (rate of variations in the maximum wind velocity), which are most pronounced in the periods of intensification and decay of the cyclones. The diurnal variations can differ notably in phase in different geographical conditions. 相似文献
13.
利用印度气象局（India Meteorological Department,IMD）、国际气候管理最佳路径档案库（International Best Track Archive for Climate Stewardship,IBTrACS）提供的1982—2020年阿拉伯海热带气旋路径资料,美国国家环境预报中心（National Centers for Environmental Prediction,NCEP）再分析资料,对近39 a阿拉伯海热带气旋源地和路径特征、活跃区域、频数及气旋累积能量（accumulated cyclone energy,ACE）指数的季节特征和年际变化特征进行分析,并结合环境因素,说明其物理成因。结果表明：阿拉伯海热带气旋多发于10°~25°N,65°~75°E海域,5—6月、9—12月发生频数较高且强度较强,1—4月、7—8月发生频数较低且气旋近中心最大风速均小于35 kn;频数的季节变化主要受控于垂直风切变要素;阿拉伯海热带气旋发生频数和ACE近年有上升趋势,年际变化主要受控于海面温度（sea surface temperature,SST）和850 hPa相对湿度要素。 相似文献
14.
伪距单点定位的精度分析及改进 总被引：1，自引：0，他引：1
GPS伪距单点定位速度快、不存在整周模糊度,因此具有很大的应用价值。分析了电离层延迟、对流层延迟、相对论效应、地球自转改正对伪距单点定位结果的影响,介绍了两种多历元求解时处理接收机钟差的方法,最后讨论了如何以大地坐标和高斯坐标为参数进行定位求解。 相似文献
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16.
利用日本气象厅"best track data"热带气旋数据、QuikSCAT(Quick Scatterometer)卫星风场数据和SCUD(Surface Currents from a Diagnostic model)表层流场数据,估算了热带气旋对南海表层流和波浪的能量输入。结果显示,由于热带气旋基本都位于南海中北部,热带气旋对表层流和波浪的能量输入也集中在南海中北部;能量输入最大的月份均在8月和11月,而在9月对总能量输入贡献最大。5～12月,热带气旋对南海表层流的能量输入为1.26GW,占风对表层流总能量输入的9.87%;热带气旋对表层波浪的能量输入为11.60GW,占风对表层波浪总能量输入的5.42%。如果只考虑10°N以北区域,则热带气旋对表层流和波浪能量输入的贡献分别达到11.29%和6.87%。 相似文献
17.
源自南海东北部海区热带气旋的若干统计特征 总被引：4，自引：0，他引：4
1949－1998年50a中，源自南海东北部海区的热带气旋共67个，其中有17a无热带气旋产生，45a无台风。该海区产生的热带气旋及其有关的统计特征与南海南部和热带西太平洋的热带气旋不同：平均个数是厄尔尼诺年较反厄尔尼诺年少；春季型的厄尔尼诺过程中热带气旋生成较多；1970－1990的的强厄尔尼诺过程中热带气旋个数当年较次年多，1990年后则相反，与历次厄尔尼诺过程比较，1997－1998年特强厄尔尼诺过程中的热带气旋生成较多、发展较快、其异常的气候特征为有史以来所罕见。 相似文献
18.
M. B. Gokhberg G. M. Steblov S. L. Shalimov V. A. Veis E. A. Grekhova 《Izvestiya Atmospheric and Oceanic Physics》2011,47(8):929-940
Using available Russian and international Global Positioning System (GPS) network data, we studied the ionospheric response
to the M = 8.9 submarine earthquake of March 11, 2011, on the northeastern coast of Honshu Island, Japan, both near and far (about
2000 km away) from the epicenter. In the region over the epicenter, 8.7 min after the event, we detected a characteristic
signal of the total electron content (TEC) variations consisting of compression and rarefaction phases and a linear transition
zone in between, i.e., in the form of an N-type wave with a steep leading front indicating a rapid uplift of the water surface and, correspondingly, the bottom of the
ocean. The shape of the signal can be used for early tsunami warning; i.e., it may indicate the tsunamigenic character of
a submarine earthquake. We monitored the subsequent evolution of the ionospheric response as far as 2000 km from the epicenter.
It was shown that, besides the wellknown ionospheric N-type wave response to the earthquake, there is also a response in the form of an inverted N-wave, both nearby and far from the epicenter. We detected two more types of ionospheric responses far from the epicenter:
a solitary-like wave and an internal gravity wave (IGW). The detected signals have been interpreted. 相似文献
19.
Three methods for identification cyclones in extratropical latitudes of the Northern Hemisphere (NH) (20°–80° L) are compared
based on reanalysis data (1948–2007) for the fields of the sea level pressure (SLP). Different characteristics of extratropical
cyclones, namely, their number, intensity, size, and lifetime, are analyzed. The effect of orographic effects for the identification
of cyclones and their trajectories is evaluated. The characteristics of extratropical cyclones are compared based on different
reanalysis data (National Center for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR), ERA-40,
and ERA-INTERIM) with different spatial resolutions. 相似文献
20.
1949-2017年南海海域热带气旋强度和路径快速变化统计特征 总被引：1，自引：1，他引：0
为进一步认识南海地区热带气旋强度和路径快速变化的统计特征，利用中国气象局上海台风研究所整编的1949–2017年的热带气旋最佳路径数据集，统计分析了不同强度等级热带气旋发生强度和路径快速变化的特征。结果表明:(1)由强热带风暴快速加强为台风、以及由台风快速加强为强台风是热带气旋强度快速加强发生频率最多的事件；强度快速加强次数以1次居多，一般不会超过2次；但大部分途经南海的热带气旋出现快速加强时都在南海以外的地区，在南海出现快速加强的概率仅为9.8%。(2)不同强度的热带气旋，其强度的维持时间长短对其强度快速加强有重要影响，一般在该强度的前24 h是快速加强的最佳阶段，当其中心气压下降速度超过?12.0 hPa/(6 h)时容易出现台风级别或以上的强度快速加强，且热带气旋快速加强容易出现在海温偏高地区。(3)南海地区热带气旋路径的偏转主要出现在西行路径中，其中以5°～30°的偏转为最常见，占到全部热带气旋总数的48.65%，不过，按照定义的路径快速转向标准，路径快速转向的概率仅有15.13%。随着热带气旋强度的增强，南海地区发生路径快速转向的频次迅速减少，路径快速转向主要出现在近海岸地区和南海中北部偏东区域。这些结果进一步细化和丰富了对南海地区热带气旋强度和路径快速变化的认识。 相似文献