{"title":"群卫星在不同太阳活动期间的电子密度及其衍生参数的半球间变化","authors":"D. Kotova, Yaqi Jin, W. Miloch","doi":"10.1051/swsc/2022007","DOIUrl":null,"url":null,"abstract":"With the data from the Swarm satellite mission, we study the variability of ionospheric plasma parameters for low and high solar activities. We focus on the electron density measured by Swarm and derived parameters, and analyze the variability of these parameters in the contexts of the northern and southern hemispheres, specific latitudinal regions, and the solar activity level. We consider two time-intervals with high solar activity (HSA) from August 2014 to July 2015 and low solar activity (LSA) from January to December 2018. We show that electron density is described mainly by three probability density functions (PDF): exponentiated Weibull, lognormal, and chi distributions. These results with PDF can be applied to modeling or prediction of ionospheric parameters in different regions. The best fit of PDFs was obtained for low and mid latitudes, while at high latitudes and in the polar caps the double-peaked features of the distribution require the fit of multiple PDFs. The electron density distribution at low latitudes follows more a lognormal distribution, while in the high latitude region the chi distribution prevails. Different results were obtained for the Rate of change of Density Index (RODI) with two fitting PDF’s: lognormal or exponentiated Weibull, where the best fits are for high latitudes and polar caps. We demonstrate high variability in the electron density and derived parameters at low latitudes and in the polar caps. Comparing both hemispheres, we obtained higher values of these parameters during the solar minimum in the southern hemisphere at high latitudes and polar caps, while for the northern hemisphere higher values were obtained at low latitudes. The dependence on the satellite’s height was also considered. The main patterns in the diurnal variation of parameters in different regions do not depend on the level of solar activity (which affects only the maximum values). The largest asymmetry between both hemispheres in Ne diurnal distribution was obtained for the polar cap regions. Here a 50% decrease in Ne was observed in the northern hemisphere during HSA in the early morning sector (04-07 Magnetic Local Time) which has not yet been observed in the southern hemisphere. For the first time, such a global statistical characterization of the ionospheric plasma density based on the in situ data is presented.","PeriodicalId":17034,"journal":{"name":"Journal of Space Weather and Space Climate","volume":" ","pages":""},"PeriodicalIF":3.4000,"publicationDate":"2022-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Interhemispheric variability of the electron density and derived parameters by the Swarm satellites during different solar activity\",\"authors\":\"D. Kotova, Yaqi Jin, W. Miloch\",\"doi\":\"10.1051/swsc/2022007\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"With the data from the Swarm satellite mission, we study the variability of ionospheric plasma parameters for low and high solar activities. We focus on the electron density measured by Swarm and derived parameters, and analyze the variability of these parameters in the contexts of the northern and southern hemispheres, specific latitudinal regions, and the solar activity level. We consider two time-intervals with high solar activity (HSA) from August 2014 to July 2015 and low solar activity (LSA) from January to December 2018. We show that electron density is described mainly by three probability density functions (PDF): exponentiated Weibull, lognormal, and chi distributions. These results with PDF can be applied to modeling or prediction of ionospheric parameters in different regions. The best fit of PDFs was obtained for low and mid latitudes, while at high latitudes and in the polar caps the double-peaked features of the distribution require the fit of multiple PDFs. The electron density distribution at low latitudes follows more a lognormal distribution, while in the high latitude region the chi distribution prevails. Different results were obtained for the Rate of change of Density Index (RODI) with two fitting PDF’s: lognormal or exponentiated Weibull, where the best fits are for high latitudes and polar caps. We demonstrate high variability in the electron density and derived parameters at low latitudes and in the polar caps. Comparing both hemispheres, we obtained higher values of these parameters during the solar minimum in the southern hemisphere at high latitudes and polar caps, while for the northern hemisphere higher values were obtained at low latitudes. The dependence on the satellite’s height was also considered. The main patterns in the diurnal variation of parameters in different regions do not depend on the level of solar activity (which affects only the maximum values). The largest asymmetry between both hemispheres in Ne diurnal distribution was obtained for the polar cap regions. Here a 50% decrease in Ne was observed in the northern hemisphere during HSA in the early morning sector (04-07 Magnetic Local Time) which has not yet been observed in the southern hemisphere. For the first time, such a global statistical characterization of the ionospheric plasma density based on the in situ data is presented.\",\"PeriodicalId\":17034,\"journal\":{\"name\":\"Journal of Space Weather and Space Climate\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":3.4000,\"publicationDate\":\"2022-03-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Space Weather and Space Climate\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1051/swsc/2022007\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Space Weather and Space Climate","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1051/swsc/2022007","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Interhemispheric variability of the electron density and derived parameters by the Swarm satellites during different solar activity
With the data from the Swarm satellite mission, we study the variability of ionospheric plasma parameters for low and high solar activities. We focus on the electron density measured by Swarm and derived parameters, and analyze the variability of these parameters in the contexts of the northern and southern hemispheres, specific latitudinal regions, and the solar activity level. We consider two time-intervals with high solar activity (HSA) from August 2014 to July 2015 and low solar activity (LSA) from January to December 2018. We show that electron density is described mainly by three probability density functions (PDF): exponentiated Weibull, lognormal, and chi distributions. These results with PDF can be applied to modeling or prediction of ionospheric parameters in different regions. The best fit of PDFs was obtained for low and mid latitudes, while at high latitudes and in the polar caps the double-peaked features of the distribution require the fit of multiple PDFs. The electron density distribution at low latitudes follows more a lognormal distribution, while in the high latitude region the chi distribution prevails. Different results were obtained for the Rate of change of Density Index (RODI) with two fitting PDF’s: lognormal or exponentiated Weibull, where the best fits are for high latitudes and polar caps. We demonstrate high variability in the electron density and derived parameters at low latitudes and in the polar caps. Comparing both hemispheres, we obtained higher values of these parameters during the solar minimum in the southern hemisphere at high latitudes and polar caps, while for the northern hemisphere higher values were obtained at low latitudes. The dependence on the satellite’s height was also considered. The main patterns in the diurnal variation of parameters in different regions do not depend on the level of solar activity (which affects only the maximum values). The largest asymmetry between both hemispheres in Ne diurnal distribution was obtained for the polar cap regions. Here a 50% decrease in Ne was observed in the northern hemisphere during HSA in the early morning sector (04-07 Magnetic Local Time) which has not yet been observed in the southern hemisphere. For the first time, such a global statistical characterization of the ionospheric plasma density based on the in situ data is presented.
期刊介绍:
The Journal of Space Weather and Space Climate (SWSC) is an international multi-disciplinary and interdisciplinary peer-reviewed open access journal which publishes papers on all aspects of space weather and space climate from a broad range of scientific and technical fields including solar physics, space plasma physics, aeronomy, planetology, radio science, geophysics, biology, medicine, astronautics, aeronautics, electrical engineering, meteorology, climatology, mathematics, economy, informatics.