International Journal of Geomagnetism and Aeronomy最新文献

{"title":"Correction to “Observations of neutral winds and electric fields using backscatter from field-aligned irregularities”","authors":"A. Mikhailov","doi":"10.1029/2004GI000086","DOIUrl":"https://doi.org/10.1029/2004GI000086","url":null,"abstract":"Ionospheric F2-layer disturbances not related to geomagnetic activity (Q disturbances) were analyzed using all available N m F2 observations over 26 Northern Hemisphere high-to-lower latitude ionosonde stations. Both positive and negative Q disturbances were revealed, their amplitude being comparable to moderate F2-layer storm effects. The occurrence of Q disturbances exhibits a systematic dependence on solar activity, season, and local time. Spatial variation pattern is different for positive and negative Q disturbances with the amplitude of the former increasing with latitude while the amplitude of the latter being practically latitudinal-independent. Longitudinal variations of the amplitude for both types of disturbances look like a planetary wave with minimal deviations in the American sector and maximal deviations in the European sector. Large longitudinal gradients in N m F2 can appear on the front of such waves.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131235413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: Introducing “Discussion Papers”","authors":"O. Raspopov, R. W. Smith","doi":"10.1029/2004GI000075","DOIUrl":"https://doi.org/10.1029/2004GI000075","url":null,"abstract":"[1] With this issue IJGA is introducing a new type of article to facilitate continuing discussion of topics of interest to readers of the journal. These “Discussion Papers” provide authors and readers an opportunity to exchange ideas on topics outside of the traditional scientific peer review process. Topics such as the relationship between different geophysical events – earthquakes and variations ionospheric or upper atmospheric parameters, or the impact of space weather on various phenomena in the atmosphere and on the surface – are appropriate for this type of contribution. [2] “Discussion Papers” are selected at the discretion of the IJGA Editors and are not formally peer reviewed. These","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"219 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116231637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies of the structure and dynamics of the D region of the polar ionosphere during solar flares in April 2004","authors":"V. Tereshchenko, E. Vasilev, O. Ogloblina, V. Tereshchenko, S. Chernyakov","doi":"10.1029/2005GI000107","DOIUrl":"https://doi.org/10.1029/2005GI000107","url":null,"abstract":"[1] The results of observations of the polar lower ionosphere by the partial reflection method during moderate solar flares in April 2004 are presented. The structure of the electron concentration profile in the ionospheric D region and the effects of the impact on it of X-ray radiation of the flares both in quiet and disturbed conditions are considered. It is shown that at altitudes below 75 km the electron concentration is proportional to the intensity of X-ray radiation from a solar flare. This manifests the existence of a linear recombination law at these heights.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129345506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron collision frequency and HF waves attenuation in the ionosphere","authors":"N. Danilkin","doi":"10.1029/2004GI000081","DOIUrl":"https://doi.org/10.1029/2004GI000081","url":null,"abstract":"[1] The results of the studies of the effective electron collision frequency and HF wave attenuation in the midlatitude ionosphere carried out in the Rostov-on-Don University during the past 35 years are presented. It is found that (besides the collision absorption) the attenuation is determined also by additional dissipative and nondissipative mechanisms. The absorption is reliably determined using the gas-kinetic model of the effective electron collision frequency. The additional dissipation mechanism (anomalous absorption of ordinary waves) may occur because of their statistical transformation into slow extraordinary waves at the scattering at small-scale fluctuations of the electron concentration. The only cause of the nondissipative attenuation is the small-angle multiple forward scattering at largescale irregularities of the ionospheric plasma. At signal propagation in the vicinity of the maximum usable frequency (MUF) the scattering provides an input into the attenuation comparable to the collision absorption. At the illumination of the ionosphere by a point source from the Earth surface, the multiple scattering leads to such distribution of the field at which the emission reflected under small angles to the vertical has an energy deficit. Presence of addition (to the collision) absorption mechanisms of HF waves attenuation leads to overestimated (as compared to the gas-kinetic ones) estimates of the electron collision frequency. The determination of the physical nature of the attenuation made it possible to develop correct methods of modeling of HF radio waves propagation in the three-dimensional inhomogeneous magnetically active ionospheric plasma and test these methods in a vast series of experiments.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123380228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Main phases of the solar cycle in the galactic cosmic ray intensity","authors":"M. Krainev","doi":"10.1029/2004GI000070","DOIUrl":"https://doi.org/10.1029/2004GI000070","url":null,"abstract":"[1] The separation of the solar cycle in the modulation of the galactic cosmic ray intensity into the four main phases (the minimum, ascending, maximum, and descending) is considered. We substantiate advantages of such classification, choose as its initial point one of the known classifications, and discuss the special features of the main phases of the solar cycle in the heliospheric and cosmic ray characteristics. The initial assumption on the physical meaning of the sought for classification is proposed. The role of the very local interstellar medium in forming the solar cycle in the heliosphere is briefly discussed. INDEX TERMS: 7536 Solar Physics, Astrophysics, and Astronomy: Solar activity cycle; 2104 Interplanetary Physics: Cosmic rays; 2134 Interplanetary Physics: Interplanetary magnetic fields; KEYWORDS: Galactic cosmic ray; Very local interstellar medium; Phases of cosmic ray modulation.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121748855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic field and turbulent velocities in the solar corona","authors":"A. B. Delone","doi":"10.1029/2004GI000088","DOIUrl":"https://doi.org/10.1029/2004GI000088","url":null,"abstract":"[1] Observations conducted by the authors during total solar eclipses in 1968, 1981, and 1999 and the results of noneclipse observations in the visual, IR, and far UV regions of the solar spectrum obtained both on the ground and in the space (according to publications of other authors) are considered. The relation of nonthermal velocities to characteristics of the magnetic field is studied. The nonthermal velocities in coronal holes are found higher than in quiet corona. In quiet corona they are higher than in the coronal cavity around a quiet prominence. A conclusion is drawn that the difference in the turbulence in various structural formations in the corona is related to the magnetic field variability.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"134 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131044427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forecasting of the critical frequency of the ionosphereF2 layer by the method of artificial neural networks","authors":"N. Barkhatov","doi":"10.1029/2004GI000065","DOIUrl":"https://doi.org/10.1029/2004GI000065","url":null,"abstract":"[1] An algorithm of forecasting of the ionosphere F2 layer critical frequency for time intervals: 1, 2, 3, 12, and 24 hours was developed on the basis of the technology of artificial neural networks (ANN). The experimental search for a valid training array and architecture of ANN was performed. The solar wind parameters, interplanetary magnetic field, and geomagnetic disturbance indexes were additionally used in the forecasting. This made it possible to improve its effectiveness. The practical importance of the performed work is in the application of its results for efficient correction of the ionosphere model for an improvement of the ionosphere shortwave radio communication.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132927604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quiet timeF2–layer disturbances at geomagnetic equator","authors":"A. Depueva","doi":"10.1029/2004GI000071","DOIUrl":"https://doi.org/10.1029/2004GI000071","url":null,"abstract":"[1] Ionospheric F2-layer disturbances not related to geomagnetic activity (Q disturbances) were analyzed using all available NmF2 observations over Huancayo (American sector) and Kodaikanal (Indian sector) stations located at the proximity of geomagnetic equator. Both positive and negative Q disturbances were revealed, their amplitude being comparable to usual F2 layer storm effects. The occurrence of Q disturbances exhibit a systematic dependence on solar activity, season, and local time. The revealed morphology of Q disturbances at Huancayo can be explained by the observed at Jicamarca E×B vertical drifts. There are some differences between Huancayo and Kodaikanal Q disturbance morphological patterns that cannot be attributed to small differences in E×B vertical drifts in the two longitudinal sectors.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116039035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discussion paper: Radial profiles of the galactic cosmic ray intensity in the extreme phases of the solar cycle","authors":"W. Webber","doi":"10.1029/2004GI000066","DOIUrl":"https://doi.org/10.1029/2004GI000066","url":null,"abstract":"[1] The data on the galactic cosmic ray intensity near the Earth and in the distant heliosphere allow determination of the radial profiles of the intensity corresponding to the minima and maxima of the solar cycles 22 and 23. These profiles and the new definitions of the residual and 11-year intensity modulations to make them independent of the phase of the 22-year variation are briefly discussed. Special attention is paid to the conditions when it could be useful using these new definitions.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133462753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In memoriam Mikhail Ivanovich Pudovkin (22 May 1933 to 18 February 2004)","authors":"O. Raspopov","doi":"10.1029/2004GI000076","DOIUrl":"https://doi.org/10.1029/2004GI000076","url":null,"abstract":"Copyright 2004 by the American Geophysical Union. 1524–4423/04/2004GI000076$18.00 M. I. Pudovkin was born on 22 May 1933 in the small town of Pargolovo in the St. Petersburg region in a large family. He graduated from the physical faculty of the Leningrad University and began postgraduate studies. A year later he was included into the second Soviet Antarctic Expedition and participated in the foundation of a new Soviet station Pionerskaya deep within the Antarctic continent. The results of the observations in the Antarctic led M. I. Pudovkin to a series of important discoveries in space physics. Together with other scientists he contributed to the formation of a new branch of space science: physics of space plasma. Soon M. I. Pudovkin made a series of important contributions to this field of science including development of the physical model of the solar wind interaction with the terrestrial magnetosphere, studies of magnetospheric substorms, development of methods of forecasting the magnetosphere state on the basis of observations of the solar magnetic fields, and study of mechanisms of the impact of solar activity on the state of the lower atmosphere and climate. M. I. Pudovkin was a distinguished specialist in all these fields and was widely known among the specialists in space physics and aeronomy. M. I. Pudovkin founded a well-known scientific school. His former students and postgraduates became well-known specialists in various branches of atmospheric and magnetospheric physics. Among their achievements are modern sophisticated models of the magnetosphere, methods of geomagnetic activity forecast, and mechanisms of solar activity impact on weather and climate. M. I. Pudovkin was a brilliant lecturer and had a rare talent as a real teacher. He was supervisor of about 50 postgraduate students. Seven of his former students received doctorate of science degrees. M. I. Pudovkin was actively involved in scientific organizational work. He was a member of the Editorial office of several national and international scientific journals, actively participated in various scientific bodies like COSPAR, IUGG, SCOSTEP, and others. M. I. Pudovkin actively participated in the work of our journal, being an Associated Editor of IJGA. All his colleagues will remember Mikhail Pudovkin and greatly miss him as a brilliant scientist and a good man.","PeriodicalId":135868,"journal":{"name":"International Journal of Geomagnetism and Aeronomy","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116804006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}