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Found 171 entries in the Bibliography.

Showing entries from 51 through 100

2018

Chinese ionospheric investigations in 2016—2017

After the release of the previous report to the Committee on Space Research (COSPAR) on progress achieved by Chinese scientists in ionospheric researches (Liu LB and Wan WX

Liu, Libo; Wan, Weixing;

Published by: Earth and Planetary Physics Published on:

YEAR: 2018 DOI: 10.26464/epp2018011

Whole Atmosphere Community Climate Model—eXtended Version 2.0 Scientific Description

Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Among them the most

Liu, Han-Li; Bardeen, Charles; Foster, Benjamin; Lauritzen, Peter; Liu, Jing; Lu, Gang; Marsh, Daniel; Maute, Astrid; McInerney, Joseph; Pedatella, Nicholas; , others;

Published by: Published on:

YEAR: 2018 DOI:

Whole Atmosphere Community Climate Model—eXtended Version 2.0 Scientific Description

Key developments have been made to the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Among them the most

Liu, Han-Li; Bardeen, Charles; Foster, Benjamin; Lauritzen, Peter; Liu, Jing; Lu, Gang; Marsh, Daniel; Maute, Astrid; McInerney, Joseph; Pedatella, Nicholas; , others;

Published by: Published on:

YEAR: 2018 DOI:

The statistic characteristics of HF Oblique Sounding Channel at mid and low latitude during ionospheric disturbance time

In this study, historical data MOFF from two HF propagation paths: Qingdao-Lanzhou and Guangzhou-Haikou at mid and low latitude, the midpoint referenced data are from two

Wang, Fei-Fei; Liu, Yu-Mei; Sun, Shu-Ji;

Published by: Published on:

YEAR: 2018 DOI: 10.1109/ISAPE.2018.8634091

Interplanetary Magnetic Field By Effects on the Polar Neutral Composition

Liu, Jing; Wang, Wenbin; Burns, Alan;

Published by: Published on:

YEAR: 2018 DOI:

Physical processes driving the thermospheric variations during the March 2015 St. Patrick's day major geomagnetic storm

Wang, Wenbin; Qian, Liying; Burns, Alan; Liu, Jing;

Published by: 42nd COSPAR Scientific Assembly Published on:

YEAR: 2018 DOI:

2017

The Storm Time Evolution of the Ionospheric Disturbance Plasma Drifts

In this paper, we use the C/NOFS and ROCSAT-1 satellites observations to analyze the storm time evolution of the disturbance plasma drifts in a 24\ h local time scale during three magnetic storms driven by long-lasting southward IMF B_z. The disturbance plasma drifts during the three storms present some common features in the periods dominated by the disturbance dynamo. The newly formed disturbance plasma drifts are upward and westward at night, and downward and eastward during daytime. Further, the disturbance plasma drifts are gradually evolved to present significant local time shifts. The westward disturbance plasma drifts gradually migrate from nightside to dayside. Meanwhile, the dayside downward disturbance plasma drifts become enhanced and shift to later local time. The local time shifts in disturbance plasma drifts are suggested to be mainly attributed to the evolution of the disturbance winds. The strong disturbance winds arisen around midnight can constantly corotate to later local time. At dayside the westward and equatorward disturbance winds can drive the F region dynamo to produce the poleward and westward polarization electric fields (or the westward and downward disturbance drifts). The present results indicate that the disturbance winds corotated to later local time can affect the local time features of the disturbance dynamo electric field.

Zhang, Ruilong; Liu, Libo; Le, Huijun; Chen, Yiding; Kuai, Jiawei;

Published by: Journal of Geophysical Research: Space Physics Published on: 10/2017

YEAR: 2017 DOI: 10.1002/2017JA024637

The non--storm time corrugated upper thermosphere: What is beyond MSIS?

Observations in the recent decade have revealed many thermospheric density corrugations/perturbations under nonstorm conditions (Kp \< 2). They are generally not captured by empirical models like Mass Spectrometer Incoherent Scatter (MSIS) but are operationally important for long-term orbital evolution of Low Earth Orbiting satellites and theoretically for coupling processes in the atmosphere-ionosphere system. We review these density corrugations by classifying them into three types which are driven respectively by the lower atmosphere, ionosphere, and solar wind/magnetosphere. Model capabilities in capturing these features are discussed. A summary table of these corrugations is included to provide a quick guide on their magnitudes, occurring latitude, local time, and season.

Liu, Huixin; Thayer, Jeff; Zhang, Yongliang; Lee, Woo;

Published by: Space Weather Published on: 06/2017

YEAR: 2017 DOI: 10.1002/swe.v15.610.1002/2017SW001618

A severe negative response of the ionosphere to the intense geomagnetic storm on March 17, 2015 observed at mid- and low-latitude stations in the China zone

In this paper, the critical frequency of F2 layer of the ionosphere (foF₂₎ and the total electron content (TEC) recorded at mid- and low-latitude observation sites near 120\textdegreeE in the China zone were used to investigate the response to a severe geomagnetic storm on March 17, 2015 (the minimum Dst -223 nT at 23 UT). The results showed that the strong geomagnetic storm caused a massive effect on the ionosphere. The characteristics of foF₂ and TEC did not show obvious perturbation during the main phase. Severe depletion of foF₂ and TEC was observed at all stations during the storm recovery period. The maximum absolute discrepancy in TEC compared with the past 27-day average value was 78 TECU, and the minimum percentage deviations reached -71\% at Fuzhou (26.1\textdegreeN,\ 119.3\textdegreeE). The minimum percentage deviations of decrease in foF₂ reached -65\% at Sanya (18.1\textdegreeN,\ 109.3\textdegreeE) and Mohe (53.5\textdegreeN,\ 122.3\textdegreeE). This was an infrequent negative effect that foF₂ and TEC sustained throughout the day with extremely low level on March 18. The O/N₂ rate showed a distinct reduction on March 18 in the China zone, which may be mainly responsible for the severe depletion of foF₂ and TEC. The spread-F seemed to be developed at first but was then suppressed to some extent during the main phase. During the recovery phase, the spread-F was suppressed at Sanya, while it developed at Wuhan and Mohe. The disturbance electric fields and thermospheric circulation may contribute to this phenomenon.

Liu, Guoqi; Shen, Hua;

Published by: Advances in Space Research Published on: 05/2017

YEAR: 2017 DOI: 10.1016/j.asr.2017.02.021

Regional differences of the ionospheric response to the July 2012 geomagnetic storm

The July 2012 geomagnetic storm is an extreme space weather event in solar cycle 24, which is characterized by a southward interplanetary geomagnetic field lasting for about 30\ h below -10\ nT. In this work, multiple instrumental observations, including electron density from ionosondes, total electron content (TEC) from Global Positioning System, Jason-2, and Gravity Recovery and Climate Experiment, and the topside ion concentration observed by the Defense Meteorological Satellite Program spacecraft are used to comprehensively present the regional differences of the ionospheric response to this event. In the Asian-Australian sector, an intensive negative storm is detected near longitude ~120\textdegreeE on 16 July, and in the topside ionosphere the negative phase is mainly existed in the equatorial region. The topside and bottomside TEC contribute equally to the depletion in TEC, and the disturbed electric fields make a reasonable contribution. On 15 July, the positive storm effects are stronger in the Eastside than in the Westside. The topside TEC make a major contribution to the enhancement in TEC for the positive phases, showing the important role of the equatorward neutral winds. For the American sector, the equatorial ionization anomaly intensification is stronger in the Westside than in the Eastside and shows the strongest feature in the longitude ~110\textdegreeW. The combined effects of the disturbed electric fields, composition disturbances, and neutral winds cause the complex storm time features. Both the topside ion concentrations and TEC reveal the remarkable hemispheric asymmetry, which is mainly resulted from the asymmetry in neutral winds and composition disturbances.

Kuai, Jiawei; Liu, Libo; Lei, Jiuhou; Liu, Jing; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Wang, Yungang; Hu, Lianhuan;

Published by: Journal of Geophysical Research: Space Physics Published on: 04/2017

YEAR: 2017 DOI: 10.1002/2016JA023844

Regional differences of the ionospheric response to the July 2012 geomagnetic storm

Kuai, Jiawei; Liu, Libo; Lei, Jiuhou; Liu, Jing; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Wang, Yungang; Hu, Lianhuan;

Published by: Journal of Geophysical Research: Space Physics Published on: 04/2017

YEAR: 2017 DOI: 10.1002/2016JA023844

The causes of thermospheric composition variations during and after major geomagnetic storms

Wang, Wenbin; Burns, Alan; Zhang, Yongliang; Liu, Jing;

Published by: Published on:

YEAR: 2017 DOI:

A severe negative response of the ionosphere to the intense geomagnetic storm on March 17, 2015 observed at mid-and low-latitude stations in the China zone

Liu, Guoqi; Shen, Hua;

Published by: Advances in Space Research Published on:

YEAR: 2017 DOI:

Analysis and design of the ultraviolet warning optical system based on interference imaging

Ultraviolet warning technology is one of the important methods for missile warning. It provides a very effective way to detect the target for missile approaching alarm. With the development of modern technology, especially the development of information technology at high speed, the ultraviolet early warning system plays an increasingly important role. Compared to infrared warning, the ultraviolet warning has high efficiency and low false alarm rate. In the modern warfare, how to detect the threats earlier, prevent and reduce the attack of precision-guided missile has become a new challenge of missile warning technology. Because the ultraviolet warning technology has high environmental adaptability, the low false alarm rate, small volume and other advantages, in the military field applications it has been developed rapidly. For the ultraviolet warning system, the optimal working waveband is 250 nm ~280 nm (Solar Blind UV) due to the strong absorption of ozone layer. According to current application demands for solar blind ultraviolet detection and warning, this paper proposes ultraviolet warning optical system based on interference imaging, which covers solar blind ultraviolet (250nm-280nm) and dual field. This structure includes a primary optical system, an ultraviolet reflector array, an ultraviolet imaging system and an ultraviolet interference imaging system. It makes use of an ultraviolet beam-splitter to achieve the separation of two optical systems. According to the detector and the corresponding application needs of two visual field of the optical system, the calculation and optical system design were completed. After the design, the MTF of the two optical system is more than 0.8@39lp/mm.A single pixel energy concentration is greater than 80\%.

Wencong, Wang; Jin, Dong-dong; Chu, Xin-bo; Shi, Yu-feng; Song, Juan; Liu, Jin-sheng; Shao, Si-pei; Hu, Hui-jun; Xiao, Ting;

Published by: Published on:

YEAR: 2017 DOI: 10.1117/12.2285832

2016

Long-lasting negative ionospheric storm effects in low and middle latitudes during the recovery phase of the 17 March 2013 geomagnetic storm

In this paper, an ionospheric electron density reanalysis algorithm was used to generate global optimized electron density during the 17\textendash18 March 2013 geomagnetic storm by assimilating ~10 low Earth orbit satellites based and ~450 ground global navigation satellite system receiver-based total electron content into a background ionospheric model. The reanalyzed electron density could identify the large-scale ionospheric features quite well during storm time, including the storm-enhanced density, the positive ionospheric storm effect during the initial and main phases, and the negative ionospheric storm effect during the recovery phase. The simulations from the Thermosphere Ionosphere Electrodynamics General Circulation Model can reproduce similar large-scale ionospheric disturbances as seen in the reanalysis results. Both the reanalysis and simulations show long-lasting (\>17 h) daytime negative storm effect over the Asia sector as well as hemispheric asymmetry during the recovery phase. Detailed analysis of the Global Ultraviolet Imager-derived O/N₂ ratio and model simulations indicate that the polar ward meridional wind disturbance, the downward E \texttimes B drift disturbance and O/N₂ depletion might be responsible for the negative storm effect. The hemispheric asymmetry is mainly caused by the geomagnetic field line configuration, which could cause hemispheric asymmetry in the O/N₂ depletion.

Yue, Xinan; Wang, Wenbin; Lei, Jiuhou; Burns, Alan; Zhang, Yongliang; Wan, Weixing; Liu, Libo; Hu, Lianhuan; Zhao, Biqiang; Schreiner, William;

Published by: Journal of Geophysical Research: Space Physics Published on: 11/2016

YEAR: 2016 DOI: 10.1002/jgra.v121.910.1002/2016JA022984

Analysis of the global ionospheric disturbances of the March 2015 great storm

The global ionospheric storm in March 2015 was investigated by using data from over 3000 GPS stations worldwide. In this study, total electron content (TEC), rate of TEC (ROT), and ROT\textquoterights standard deviation rate of the TEC index, as well as the second-order difference operator TECT, were considered as main characteristic methods to distinguish ionosphereic disturbances. The results show that (1) based on the multiple methods above, we all observed that for the first time, there were three equatorward traveling ionospheric disturbances (TIDs) in the main phase of this storm. In North America, the disturbance zone expanded to ~40\textdegreeN; the disturbance periods and AE peak stages were roughly synchronous. We suggest that these three TIDs were induced by the propagation of atmospheric gravity waves to low latitudes under the action of AE. (2) The most intense positive storm occurred over South America and the South Atlantic (over 300\% enhancement; 00:00\textendash05:00 UT on 18 March), whereas a negative storm was observed in the corresponding region of the Northern Hemisphere. Such inverse hemispheric asymmetry in intensity and structure can be explained by the variations of the thermospheric composition, the IMF B_y component, and the geomagnetic intensity. (3) On 18 March, a negative storm dominated globally (except at certain low latitudes), and tended to propagate equatorward and decay with time, which could be largely attributed to the storm circulation theory. And the evolution of the negative storm was further characterized by the f_oF₂ variations of ionosondes.

Yao, Yibin; Liu, Lei; Kong, Jian; Zhai, Changzhi;

Published by: Journal of Geophysical Research: Space Physics Published on: 11/2016

YEAR: 2016 DOI: 10.1002/2016JA023352

Variability and predictability of the space environment as related to lower atmosphere forcing

The Earth\textquoterights thermosphere and ionosphere (TI) are characterized by perpetual variability as integral parts of the atmosphere system, with intermittent disturbances from solar and geomagnetic forcing. This review examines how the TI variability is affected by processes originating from the lower atmosphere and implications for quantifying and forecasting the TI. This aspect of the TI variability has been increasingly appreciated in recent years from both observational and numerical studies, especially during the last extended solar minimum. This review focuses on the role of atmospheric waves, including tides, planetary waves, gravity waves, and acoustic waves, which become increasingly significant as they propagate from their source region to the upper atmosphere. Recent studies have led to better understanding of how these waves directly or indirectly affect TI wind, temperature, and compositional structures; the circulation pattern; neutral and ion species transport; and ionospheric wind dynamo. The variability of these waves on daily to interannual scales has been found to significantly impact the TI variability. Several outstanding questions and challenges have been highlighted: (i) large, seemingly stochastic, day-to-day variability of tides in the TI; (ii) control of model error in the TI region by the lower atmosphere; and (iii) the increasing importance of processes with shorter spatial and temporal scales at higher altitudes. Addressing these challenges requires model capabilities to assimilate observations of both lower and upper atmosphere and higher model resolution to capture complex interactions among processes over a broad range of scales and extended altitudes.

Liu, H.-L.;

Published by: Space Weather Published on: 09/2016

YEAR: 2016 DOI: 10.1002/2016SW001450

The observation and simulation of ionospheric response to CIR/high-speed streams-induced geomagnetic activity on 4 April 2005

The ionospheric response to corotating interaction region (CIR)-induced geomagnetic activity on 4 April 2005 has been studied using in situ electron density measurements, ground GPS-total electron content (TEC) observations, and numerical simulations of the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). The case study resulted that the ionospheric positive response occurred from high to low latitudes. The positive effect at low latitudes could continue for 4 days, whereas at middle to high latitudes the disturbance mainly lasted only for 1 day. The modeled Ne and TEC from TIE-GCM had a good agreement with those from observations. The simulation results showed that penetration electric fields were responsible for the daytime positive response during the initial and main phases of the geomagnetic storm, while neutral winds were responsible for the presunset positive effects. The long-lasting positive storm effect during the storm recovery time at low latitudes was related to the thermospheric composition (O/N 2 ) changes during the storm event.

Chen, Yanhong; Wang, Wenbin; Qiu, Na; Liu, Siqing; Gong, Jiancun; Huang, Wengeng;

Published by: Radio Science Published on: 08/2016

YEAR: 2016 DOI: 10.1002/rds.v51.810.1002/2015RS005937

Equatorial ionospheric plasma drifts and O ⁺ concentration enhancements associated with disturbance dynamo during the 2015 St. Patrick\textquoterights Day magnetic storm

Disturbance dynamo is an important dynamic process during magnetic storms. However, very few direct observations of dynamo-induced plasma drifts and ion composition changes in the equatorial ionosphere are available. In this study, we use measurements of the Defense Meteorological Satellite Program (DMSP) satellites to identify the characteristics of the disturbance dynamo process in the topside equatorial ionosphere near dawn during the magnetic storm with a minimum Dst of -223 nT on 17 March 2015. Data from four DMSP satellites with equatorial crossings at 0245, 0430, 0630, and 0730 LT are available for this case. The dynamo process was first observed in the postmidnight sector 3\textendash4.7 h after the beginning of the storm main phase and lasted for 31 h, covering the second storm intensification and the initial 20 h of the recovery phase. The dynamo vertical ion drift was upward (up to 150\textendash200 m s^-1) in the postmidnight sector and downward (up to ~80 m s^-1) in the early morning sector. The dynamo zonal ion drift was westward at these locations and reached ~100 m s^-1. The dynamo process caused large enhancements of the O⁺ concentration (the ratio of the oxygen ion density to the total ion density) at the altitude of 840 km near dawn. The O⁺ concentration increased from below 60\% during the prestorm period to 80\textendash90\% during the storm time. More specifically, the O⁺ density was increased, and the H⁺ density was decreased. The variations of the O⁺ concentration were well correlated with the vertical ion drift.

Huang, Chao-Song; Wilson, Gordon; Hairston, Marc; Zhang, Yongliang; Wang, Wenbin; Liu, Jing;

Published by: Journal of Geophysical Research: Space Physics Published on: 06/2016

YEAR: 2016 DOI: 10.1002/2016JA023072

Ionospheric data assimilation with thermosphere-ionosphere-electrodynamics general circulation model and GPS-TEC during geomagnetic storm conditions

The main purpose of this paper is to investigate the effects of rapid assimilation-forecast cycling on the performance of ionospheric data assimilation during geomagnetic storm conditions. An ensemble Kalman filter software developed by the National Center for Atmospheric Research (NCAR), called Data Assimilation Research Testbed, is applied to assimilate ground-based GPS total electron content (TEC) observations into a theoretical numerical model of the thermosphere and ionosphere (NCAR thermosphere-ionosphere-electrodynamics general circulation model) during the 26 September 2011 geomagnetic storm period. Effects of various assimilation-forecast cycle lengths: 60, 30, and 10 min on the ionospheric forecast are examined by using the global root-mean-squared observation-minus-forecast (OmF) TEC residuals. Substantial reduction in the global OmF for the 10 min assimilation-forecast cycling suggests that a rapid cycling ionospheric data assimilation system can greatly improve the quality of the model forecast during geomagnetic storm conditions. Furthermore, updating the thermospheric state variables in the coupled thermosphere-ionosphere forecast model in the assimilation step is an important factor in improving the trajectory of model forecasting. The shorter assimilation-forecast cycling (10 min in this paper) helps to restrain unrealistic model error growth during the forecast step due to the imbalance among model state variables resulting from an inadequate state update, which in turn leads to a greater forecast accuracy.

Chen, C.; Lin, C.; Matsuo, T.; Chen, W.; Lee, I.; Liu, J; Lin, J.; Hsu, C.;

Published by: Journal of Geophysical Research: Space Physics Published on: 05/2016

YEAR: 2016 DOI: 10.1002/2015JA021787

New understanding achieved from 2 years of Chinese ionospheric investigations

In the mainland of China, the number of ionospheric research groups is more than 10. Around 110 articles related to ionospheric physics have been published during 2014–2015. In this annual national report of the Committee on Space Research (COSPAR), we will outline some recent progresses in ionospheric studies conducted by the Chinese mainland scientists in the past 2 years.

Liu, Libo; Wan, Weixing;

Published by: Science Bulletin Published on:

YEAR: 2016 DOI: 10.1007/s11434-016-1035-9

Ionospheric responses to geomagnetic storms during 2015-2016 at longitude 120° E in China

Chen, Yanhong; Tianjiao, Yuan; Hua, Shen; Liu, Siqing; Wengeng, Huang; Gong, Jiancun;

Published by: Published on:

YEAR: 2016 DOI:

Equatorial ionospheric plasma drifts and O+ concentration enhancements associated with disturbance dynamo during the 2015 St. Patrick's Day magnetic storm

Huang, Chao-Song; Wilson, Gordon; Hairston, Marc; Zhang, Yongliang; Wang, Wenbin; Liu, Jing;

Published by: Journal of Geophysical Research: Space Physics Published on:

YEAR: 2016 DOI:

Profiles of ionospheric storm-enhanced density during the 17 March 2015 great storm

Liu, Jing; Wang, Wenbin; Burns, Alan; Yue, Xinan; Zhang, Shunrong; Zhang, Yongliang; Huang, Chaosong;

Published by: Journal of Geophysical Research: Space Physics Published on:

YEAR: 2016 DOI:

2015

The August 2011 URSI World Day campaign: Initial results

During a 10-day URSI World Day observational campaign beginning on August 1, 2011, an isolated, major geomagnetic storm occurred. On August 5,\ Kp\ reached values of 8^-and\ Dst\ dropped to -113\ nT. The occurrence of this isolated storm in the middle of a 10-day URSI World Day campaign provides and unprecedented opportunity to observe the coupling of solar wind energy into the magnetosphere and to evaluate the varied effects that occur in the coupled magnetosphere\textendashionosphere\textendashthermosphere system. Dramatic changes in the ionosphere are seen at every one of the active radar stations, extending from Greenland down to equatorial Peru in the American sector and at middle latitudes in Ukraine. Data from TIMED and THEMIS are shown to support initial interpretations of the observations, where we focus on processes in the middle latitude afternoon sector during main phase, and the formation of a dense equatorial ionosphere during storm recovery. The combined measurements strongly suggest that the changes in ionospheric conditions observed after the main storm phase can be attributed in large part to changes in the stormtime thermosphere. This is through the generation of disturbance dynamo winds and also global neutral composition changes that either reduce or enhance plasma densities in a manner that depends mainly upon latitude. Unlike larger storms with possibly more sustained forcing, this storm exhibits minimal effects of persistent meridional stormtime wind drag, and little penetration of solar wind electric potentials to low latitudes. It is, therefore, an outstanding example of an impulsive event that exhibits longer-term effects through modification of the background atmosphere.

Immel, Thomas; Liu, Guiping; England, Scott; Goncharenko, Larisa; Erickson, Philip; Lyashenko, Mykhaylo; Milla, Marco; Chau, Jorge; Frey, Harald; Mende, Stephen; Zhou, Qihou; Stromme, Anja; Paxton, Larry;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 11/2015

YEAR: 2015 DOI: 10.1016/j.jastp.2015.09.005

Aeronomy; Ionosphere; Radar; thermosphere

Explaining solar cycle effects on composition as it relates to the winter anomaly

The solar cycle variation of\ F₂\ region winter anomaly is related to solar cycle changes in the latitudinal winter-to-summer difference of O/N₂. Here we use the National Center for Atmospheric Research\textendashGlobal Mean Model to develop a concept of why the latitudinal winter-to-summer difference of O/N₂\ varies with solar cycle. The main driver for these seasonal changes in composition is vertical advection, which is expressed most simply in pressure coordinates. Meridional winds do not change over the solar cycle, so the vertical winds should also not change. The other component of vertical advection is the vertical gradient of composition. Is there any reason that this should change? At solar maximum vertical temperature gradients between 100 and 200 km altitude are strong, whereas they are weak at solar minimum. To maintain the same pressure, the weak vertical temperature gradients at solar minimum must be balanced by weak density gradients and the strong temperature gradients at solar maximum must be balanced by strong density gradients to obtain the same pressure profile. Changes in the vertical density gradients are species dependent: heavy species change more and light species change less than the average density change. Hence, vertical winds act on stronger O/N₂\ gradients at solar maximum than they do at solar minimum, and a stronger winter-to-summer difference of O/N₂\ occurs at solar maximum compared with solar minimum.

Burns, A.; Solomon, S.; Wang, W.; Qian, L.; Zhang, Y.; Paxton, L.; Yue, X.; Thayer, J.; Liu, H.;

Published by: Journal of Geophysical Research: Space Physics Published on: 07/2015

YEAR: 2015 DOI: 10.1002/2015JA021220

composition; solar cycle; upper atmosphere

Multiday thermospheric density oscillations associated with variations in solar radiation and geomagnetic activity

Thermospheric densities observed by Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites during 2002\textendash2010 and the globally averaged thermospheric densities from 1967 to 2007 have been used to investigate latitudinal, longitudinal, and height dependences of the multiday oscillations of thermospheric densities. The data show that the main multiday oscillations in thermospheric densities are 27, 13.5, 9, and 7 day oscillations. The high-correlation coefficients between the density oscillations and theF_10.7\ or\ Ap\ index indicate that these oscillations are externally driven. The 27 day density oscillation, being the strongest, is induced by variations in solar radiation, as well as recurrent geomagnetic activity that is the result of corotating interaction regions (CIRs) and high-speed solar wind streams of coronal hole origin. Density oscillations at periods of 13.5, 9, and 7 days at solar minimum and during the declining phase are stronger than those at solar maximum. These oscillations are mainly associated with recurrent geomagnetic activity due to coronal hole high-speed streams and CIRs. The multiday, periodic oscillations of thermospheric density exhibit strong latitudinal and longitudinal variations in the geomagnetic coordinate and oscillate synchronously at different heights. Oscillations with zonal wave number 0 oscillate globally, whereas those with nonzero wave numbers are strong at high geomagnetic latitudes, and hemispherically asymmetric. They are stronger in the Southern Hemisphere. The spectral distributions of thermospheric densities at different heights have almost the same latitude and longitude structures, but the spectral magnitudes increase with height.

Xu, JiYao; Wang, Wenbin; Zhang, Shunrong; Liu, Xiao; Yuan, Wei;

Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015

YEAR: 2015 DOI: 10.1002/2014JA020830

oscillation; thermospheric density

Ionospheric response to CIR-induced recurrent geomagnetic activity during the declining phase of solar cycle 23

This paper presents an epoch analysis of global ionosphere responses to recurrent geomagnetic activity during 79 corotating interaction region (CIR) events from 2004 to 2009. The data used were GPS total electron content (TEC) data from the Madrigal Database at the Massachusetts Institute of Technology Haystack Observatory and the electron density (Ne) data obtained from CHAllenging Minisatellite Payload (CHAMP) observations. The results show that global ionosphere responses to CIR events have some common features. In high and middle latitudes, the total electron content (TEC) showed a significant positive response (increased electron densities) in the first epoch day. A negative TEC response occurred at high latitudes of the American sector following the positive response. The CHAMP Ne showed a daytime positive response in all latitudes and a nighttime negative response in the subauroral region. These negative TEC and Ne responses were found to be related to thermospheric composition (O/N₂) changes during the storms. At all latitudes, the maximum of the TEC positive effect always occurred at 2\textendash6 h after the CIR starting during local daytime and 10\textendash18 h later for the CIR onset during local nighttime. Case studies indicate that the TEC and Ne positive response had a strong dependence on the southward component (Bz) of the interplanetary magnetic field and solar wind speed. This suggests that penetration electric fields that were associated with changes in solar winds might play a significant role in the positive ionospheric response to storms. During the recovery time of the CIR-produced geomagnetic activity, the TEC positive disturbance at low latitudes sometimes could last for 2\textendash4 days, whereas at middle to high latitudes the disturbance lasted only for 1 day in most cases. A comparison of the ionospheric responses between the American, European and Asian sectors shows that the ionosphere response in the North American sector was stronger than that in the other two regions. The response of f_oF₂ to the CIR events in middle to high latitudes showed a negative response for 2\textendash3 days after the first epoch day. This is different from the response of TEC, which was mostly positive during the same period of time.

Chen, Yanhong; Wang, Wenbin; Burns, Alan; Liu, Siqing; Gong, Jiancun; Yue, Xinan; Jiang, Guoying; Coster, Anthea;

Published by: Journal of Geophysical Research: Space Physics Published on: 02/2015

YEAR: 2015 DOI: 10.1002/2014JA020657

CIR events; epoch study; Ionospheric response; recurrent geomagnetic activity

The long-duration positive storm effects in the equatorial ionosphere over Jicamarca

The long-duration positive storm (LPS) in the equatorial regions is relatively poorly understood. In this report, we conducted a statistical analysis of the LPS effects in the equatorial ionosphere over Jicamarca (12.0\textdegreeS, 283.2\textdegreeE) in 1998\textendash2010. There are 250 geomagnetic storms (minimum Dst \< -50 nT) in 1998\textendash2010, but the ionosonde observations at Jicamarca are available only for 204 storms. A total of 46 LPSs are identified in terms of the criterion that the storm time relative deviation of peak density of F₂ layer (N_mF₂) exceeds 25\% for more than 6 h. A salient feature is that the occurrence of LPSs tends to decay approximately exponentially on the following days after the main phase of geomagnetic storms. The ratios of the number of equatorial LPSs to that of geomagnetic storms have no obvious dependence on season and solar activity. During the daytime LPSs, the disturbed zonal electric field is mostly westward, as indicated from the geomagnetic field changes in the equatorial American region. For the nighttime LPSs, the significant uplifting of F₂ layer caused by an eastward electric field is the most important feature. Therefore, the disturbed electric field should play an essential role in forming the equatorial LPSs.

Kuai, Jiawei; Liu, Libo; Liu, Jing; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Wan, Weixing;

Published by: Journal of Geophysical Research: Space Physics Published on: 02/2015

YEAR: 2015 DOI: 10.1002/2014JA020552

ionospheric long-duration positive storms

The long-duration positive storm effects in the equatorial ionosphere over Jicamarca

Kuai, Jiawei; Liu, Libo; Liu, Jing; Zhao, Biqiang; Chen, Yiding; Le, Huijun; Wan, Weixing;

Published by: Journal of Geophysical Research: Space Physics Published on: 02/2015

YEAR: 2015 DOI: 10.1002/2014JA020552

ionospheric long-duration positive storms

Impacts of Stratospheric Dynamics on Atmospheric Behavior from the Ground to Space Solar Minimum and Solar Maximum

In this work, we have achieved the project goal by 1 enhancing, testing, and delivering WACCM-X model to the overall project PI, Dr. F. Sassi and the NRL team 2 enabling coupling of

Liu, Han-Li;

Published by: Published on:

YEAR: 2015 DOI:

Observations and modeling of UHF-band scintillation occurrence probability over the low-latitude region of China during the maximum activity of solar cycle 24

The climatological characteristics of UHF-band scintillations over the low-latitude region of China were investigated by analyzing the observations recorded at three stations of our

Zhang, Hongbo; Liu, Yumei; Wu, Jian; Xu, T; Sheng, D;

Published by: Published on:

YEAR: 2015 DOI: 10.5194/angeo-33-93-2015

Auroral Oval Boundary Modeling Based on Deep Learning Method

Research on the location of the auroral oval is important to understand the coupling processes of the Sun-Earth system. The equatorward boundary and poleward boundary of the auroral oval are significant parameters of the auroral oval location. Thus auroral oval boundary modeling is an efficient way to study the location of auroral oval. As the location of the auroral oval boundary is subject to a variety of geomagnetic factors, there are some limitations on traditional methods, which express the auroral oval boundary as a function of only one or several geomagnetic activity index. Deep learning method is used in this paper to learn the essential features of the inputs, which are a large number of geomagnetic parameters and the former locations of aurora boundary. Furthermore, a model is established to forecast the location of the auroral oval boundary. The experiment results show that our method can model and forecast the boundary of aurora oval efficiently on the data set obtained from Ultraviolet Imager (UVI) on Polar satellite and OMNI database on NASA.

Han, Bing; Gao, Xinbo; Liu, Hui; Wang, Ping;

Published by: Published on:

YEAR: 2015 DOI: 10.1007/978-3-319-23862-310.1007/978-3-319-23862-3_10

2014

A case study of ionospheric storm effects during long-lasting southward IMF B _z -driven geomagnetic storm

Multiple instrumental observations including GPS total electron content (TEC), f_oF₂ and h_mF₂ from ionosondes, vertical ion drift measurements from Communication/Navigation Outage Forecasting System, magnetometer data, and far ultraviolet airglow measured by Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) are used to investigate the profound ionospheric disturbances at midlatitude and low latitude during the 14\textendash17 July 2012 geomagnetic storm event, which was featured by prolonged southward interplanetary geomagnetic field component for about 30 h below -10 nT. In the East Asian/Australian sector, latitudinal profile of TEC variations in the main phase were characterized by three bands of increments and separated by weak depressions in the equatorial ionospheric anomaly (EIA) crest regions, which were caused by the combined effects of disturbance dynamo electric fields (DDEF) and equatorward neutral winds. In the recovery phase, strong inhibition of EIA occurred and the summer crest of EIA disappeared on 16 July due to the combined effects of intrusion of neutral composition disturbance zone as shown by the TIMED/GUVI O/N₂ measurements and long-lasting daytime westward DDEF inferred from the equatorial electrojet observations. The transit time of DDEF over the dip equator from westward to eastward is around 2200 LT. In the American longitude, the salient ionospheric disturbances in the summer hemisphere were characterized by daytime periodical intrusion of negative phase for three consecutive days in the recovery phase, preceded by storm-enhanced density plume in the initial phase. In addition, multiple short-lived prompt penetration electric fields appeared during stable southward interplanetary magnetic field (IMF) B_z in the recovery phase and were responsible for enhanced the EIA and equatorial ionospheric uplift around sunset.

Liu, Jing; Liu, Libo; Nakamura, Takuji; Zhao, Biqiang; Ning, Baiqi; Yoshikawa, A.;

Published by: Journal of Geophysical Research: Space Physics Published on: 09/2014

YEAR: 2014 DOI: 10.1002/jgra.v119.910.1002/2014JA020273

GUVI; Ionospheric storm; prompt penetration electric fields; TIMED

A case study of ionospheric storm effects during long-lasting southward IMF B _z -driven geomagnetic storm

Liu, Jing; Liu, Libo; Nakamura, Takuji; Zhao, Biqiang; Ning, Baiqi; Yoshikawa, A.;

Published by: Journal of Geophysical Research: Space Physics Published on: 09/2014

YEAR: 2014 DOI: 10.1002/jgra.v119.910.1002/2014JA020273

GUVI; Ionospheric storm; prompt penetration electric fields; TIMED

Spherical cap harmonic analysis of the Arctic ionospheric TEC for one solar cycle

Precise knowledge of the Arctic ionosphere total electron content (TEC) and its variations has scientific relevance due to the unique characteristics of the polar ionosphere. Understanding the Arctic TEC is also important for precise positioning and navigation in the Arctic. This study utilized the spherical cap harmonic analysis (SCHA) method to map the Arctic TEC for the most recent solar cycle from 2000 to 2013 and analyzed the distributions and variations of the Arctic TEC at different temporal and spatial scales. Even with different ionosphere conditions during the solar cycle, the results showed that the existing International Global Navigation Satellite Systems Service stations are sufficient for mapping the Arctic TEC. The SCHA method provides adequate accuracy and resolution to analyze the spatiotemporal distributions and variations of the Arctic TEC under different ionosphere conditions and to track ionization patches in this polar region (e.g., the ionization event of 26 September 2011). The results derived from the SCHA model were compared to direct observations using the Super Dual Auroral Radar Network radar. The SCHA method is able to predict the TEC in the long and short terms. This paper presented a long-term prediction with a relative uncertainty of 75\% for a latency of one solar cycle and a short-term prediction with errors of \textpm2.2 total electron content units (TECUs, 1 TECU = 10¹⁶ el m^-2), \textpm3.8 TECU, and \textpm4.8 TECU for a latency of 1, 2, and 3 days, respectively. The SCHA is an effective method for mapping, predicting, and analyzing the Arctic TEC.

Liu, Jingbin; Chen, Ruizhi; An, Jiachun; Wang, Zemin; Hyyppa, Juha;

Published by: Journal of Geophysical Research: Space Physics Published on: 01/2014

YEAR: 2014 DOI: 10.1002/2013JA019501

Arctic navigation; ionosphere mapping and prediction; polar ionosphere; regional ionosphere model; spherical cap harmonic analysis

A case study of ionospheric storm effects during long-lasting southward IMF Bz-driven geomagnetic storm

Liu, Jing; Liu, Libo; Nakamura, Takuji; Zhao, Biqiang; Ning, Baiqi; Yoshikawa, A;

Published by: Journal of Geophysical Research: Space Physics Published on:

YEAR: 2014 DOI:

A case study of ionospheric storm effects during long-lasting southward IMF Bz-driven geomagnetic storm

Liu, Jing; Liu, Libo; Nakamura, Takuji; Zhao, Biqiang; Ning, Baiqi; Yoshikawa, A;

Published by: Journal of Geophysical Research: Space Physics Published on:

YEAR: 2014 DOI:

2013

On the fast zonal transport of the STS-121 space shuttle exhaust plume in the lower thermosphere

Meier et al. (2011) reported rapid eastward transport of the STS-121 space shuttle (launch: July 4, 2006) main engine plume in the lower thermosphere, observed in hydrogen Lyman α images by the GUVI instrument onboard the TIMED satellite. In order to study the mechanism of the rapid zonal transport, diagnostic tracer calculations are performed using winds from the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM) simulation of July, 2006. It is found that the strong eastward jet at heights of 100\textendash110\ km, where the exhaust plume was deposited, results in a persistent eastward tracer motion with an average velocity of 45\ m/s. This is generally consistent with, though faster than, the prevailing eastward shuttle plume movement with daily mean velocity of 30\ m/s deduced from the STS-121 GUVI observation. The quasi-two-day wave (QTDW) was not included in the numerical simulation because it was found not to be large. Its absence, however, might be partially responsible for insufficient meridional transport to move the tracers away from the fast jet in the simulation. The current study and our model results from Yue and Liu (2010) explain two very different shuttle plume transport scenarios (STS-121 and STS-107 (launch: January 16, 2003), respectively): we conclude that lower thermospheric dynamics is sufficient to account for both very fast zonal motion (zonal jet in the case of STS-121) and very fast meridional motion to polar regions (large QTDW in the case of STS-107).

Yue, Jia; Liu, Han-Li; Meier, R.R.; Chang, Loren; Gu, Sheng-Yang; , Russell;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: Jan-03-2013

YEAR: 2013 DOI: 10.1016/j.jastp.2012.12.017

Modeling; thermosphere; Transport; Wind jet

Thermospheric tidal effects on the ionospheric midlatitude summer nighttime anomaly using SAMI3 and TIEGCM

This paper is the first study to employ a three-dimensional physics-based ionosphere model, SAMI3, coupled with the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) and Global Scale Wave Model to simulate the mesospheric and lower thermospheric tidal effects on the development of midlatitude summer nighttime anomaly (MSNA). Using this coupled model, the diurnal variation of MSNA electron densities at 300 km altitude is simulated on both June solstice (day of year (DOY) 167) and December solstice (DOY 350) in 2007. Results show successful reproduction of the southern hemisphere MSNA structure including the eastward drift feature of the southern MSNA, which is not reproduced by the default SAMI3 runs using the neutral winds provided by the empirical Horizontal Wind Model 93 neutral wind model. A linear least squares algorithm for extracting tidal components is utilized to examine the major tidal component affecting the variation of southern MSNA. Results show that the standing diurnal oscillation component dominates the vertical neutral wind manifesting as a diurnal eastward wave-1 drift of the southern MSNA in the local time frame. We also find that the stationary planetary wave-1 component of vertical neutral wind can cause diurnal variation of the summer nighttime electron density enhancement around the midlatitude ionosphere.

Chen, C.; Lin, C.; Chang, L.; Huba, J.; Lin, J.; Saito, A.; Liu, J;

Published by: Journal of Geophysical Research: Space Physics Published on: 06/2013

YEAR: 2013 DOI: 10.1002/jgra.50340

MSNA; SAMI3; tidal effect; TIEGCM

Ground-based GPS observation of SED-associated irregularities over CONUS

\ It has been known that steep total electron content (TEC) gradients observed at the boundary between the storm-enhanced plasma density (SED) and the low TEC region at subauroral and midlatitude regions are associated with ionospheric irregularities that impact communication and navigation systems. However, the relationship between the SED-associated irregularities and TEC gradients is still not well understood, partly because of the difficulties of resolving small-scale TEC gradients from sparsely distributed TEC observations. In this study, we examine the relationship between the SED-associated irregularities and TEC gradients during the intense geomagnetic storms of 31 March 2001 and 30 October 2003. To explore this relationship, TEC maps over the continental United States (CONUS) were constructed from ground-based GPS TEC observations, using Kalman filter update formulae with a recently developed nonstationary wavelet-based covariance model that enables resolution of TEC structures on both large and finer scales. Our results show that intense TEC gradients and ion drifts are thought to be required conditions for the formation of irregularities on the northeast side of the SED. Additionally, our methodology identified the narrow east-west stretch of TEC enhancement within the midlatitude low TEC region on 30 October 2003, and this TEC enhancement is most likely to be caused by auroral precipitation.

Sun, Yang-Yi; Matsuo, Tomoko; Araujo-Pradere, Eduardo; Liu, Jann-Yenq;

Published by: Journal of Geophysical Research: Space Physics Published on: 05/2013

YEAR: 2013 DOI: 10.1029/2012JA018103

data assimilation; irregularity; nonstationary covariance; SED; TEC gradient

Large-scale ionospheric disturbances due to the dissipation of convectively-generated gravity waves over Brazil

In a companion paper, we show that large-scale secondary gravity waves and circulation cells are created by the body forces generated by the dissipation of convectively generated gravity waves over Brazil on 01 October 2005. In this paper, we show that these fluid perturbations cause large-scale perturbations of the plasma drift and plasma density in the ionosphere by changing the wind dynamo and transport. These fluid perturbations modify both the amplitude and direction of the plasma drifts. Near the geomagnetic equator, the magnitude of the pre-reversal enhancement can be increased or weakened, depending on the location and local time. Because the circulation cells persist from late afternoon through midnight, the modulation of the vertical drift near the geomagnetic equator persists until midnight. The largest changes of the wind-driven currents can occur either in the E or F region and are determined by the magnitudes of the wind perturbations, conductivities, and conductivity perturbations. The contributions to the plasma transport changes are from advection by the neutral winds along field lines, plasma drifts, and ambipolar diffusion, in the order of their relative significance in the numerical results.

Liu, H.-L.; Vadas, S.;

Published by: Journal of Geophysical Research: Space Physics Published on: 05/2013

YEAR: 2013 DOI: 10.1002/jgra.50244

atmosphere coupling; atmosphere gravity wave; ionospheric variability; tropospheric convection

Physical mechanisms of the ionospheric storms at equatorial and higher latitudes during the recovery phase of geomagnetic storms

The paper studies the physical mechanisms of the ionospheric storms at equatorial and higher latitudes, which are generally opposite both during the main phase (MP) and recovery phase (RP) of geomagnetic storms. The mechanisms are based on the natural tendency of physical systems to occupy minimum energy state which is most stable. The paper first illustrates the recent developments in the understanding of the mechanisms during daytime MPs when generally negative ionospheric storms (in Nmax and TEC) develop at equatorial latitudes and positive storms occur at higher latitudes, including why the storms are severe only in some cases. The paper then investigates the relative importance of the physical mechanisms of the positive ionospheric storms observed at equatorial latitudes (within \textpm15\textdegree) during daytime RPs when negative storms occur at higher latitudes using CHAMP Ne and GPS-TEC data and Sheffield University Plasmasphere Ionosphere Model. The results indicate that the mechanical effect of the storm-time equatorward neutral winds that causes plasma convergence at equatorial F region could be a major source for the positive storms, with the downwelling effect of the winds and zero or westward electric field, if present, acting as minor sources.

Balan, N.; Otsuka, Y.; Nishioka, M.; Liu, J; Bailey, G.;

Published by: Journal of Geophysical Research: Space Physics Published on: 05/2013

YEAR: 2013 DOI: 10.1002/jgra.50275

Geomagnetic storms; Ionospheric storms; physical mechanisms

Impacts of atmospheric ultrafast Kelvin waves on radio scintillations in the equatorial ionosphere

We present a statistical analysis of the amplitudes of GPS scintillations (S4 index) observed throughout 2008\textendash2010 using the satellite radio occultation measurements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Here, for the first time, periodic variability in the occurrence of S4 is investigated using these data. Significant variations of S4 with periods of 2.5\textendash4 days (quasi-3 days) are identified from the observations during postsunset hours (1900\textendash2400 local time) between 15\textdegreeS\textendash 15\textdegreeN magnetic latitude during this 3 year interval. Coherence analyses of these variations with the geomagnetic Ap index, solar EUV irradiance, and atmospheric wind measurements from an equatorial mesosphere meteor radar at Thumba, India ( 8.5\textdegreeN, 77\textdegreeE) are performed, providing a measure of the relationship between variations in the scintillations and potential drivers. The quasi-3 day variations in S4 are found to covary with the variations of the three drivers examined. In particular, the S4 signatures are found to be coherent with the atmospheric ultrafast Kelvin (UFK) planetary waves characterized by the zonal wind measurements of the radar. This study shows that these UFK waves are as important as the solar and geomagnetic drivers in forcing the day-to-day variations of the occurrence of equatorial spread F.

Liu, Guiping; Immel, Thomas; England, Scott; Frey, Harald; Mende, Stephen; Kumar, Karanam; Ramkumar, Geetha;

Published by: Journal of Geophysical Research: Space Physics Published on: 02/2013

YEAR: 2013 DOI: 10.1002/jgra.50139

day-to-day variability; Equatorial ionosphere; scintillation; Ultra Fast Kelvin planetary wave

East-west differences in F -region electron density at midlatitude: Evidence from the Far East region

The global configuration of the geomagnetic field shows that the maximum east-west difference in geomagnetic declination of northern middle latitude lies in the US region (~32\textdegree), which produces the significant ionospheric east-west coast difference in terms of total electron content first revealed by Zhang et al. (2011). For verification, it is valuable to investigate this feature over the Far East area, which also shows significant geomagnetic declination east-west gradient but smaller (~15\textdegree) than that of the US. The current study provides evidence of the longitudinal change supporting the thermospheric zonal wind mechanism by examining the climatology of peak electron density (NmF2), electron density (Ne) of different altitudes in the Far East regions with a longitude separation of up to 40\textendash60\textdegree based on ground ionosonde and space-based measurements. Although the east-west difference (R_ew) over the Far East area displays a clear diurnal variation similar to the US feature, that is negative R_ew (West Ne \> East Ne) in the noon and positive at evening-night, the observational results reveal more differences including: (1) The noontime negative R_ew is most pronounced in April\textendashJune while in the US during February\textendashMarch. Thus, for the late spring and summer period negative R_ew over the Far East region is more significant than that of the US. (2) The positive R_ew at night is much less evident than in the US, especially without winter enhancement. (3) The magnitude of negative R_ew tends to enhance toward solar maximum while in the US showing anticorrelation with the solar activity. The altitude distribution of pronounced negative difference (300\textendash400 km) moves upward as the solar flux increases and hence produces the different solar activity dependence at different altitude. The result in the paper is not simply a comparison corresponding to the US results but raises some new features that are worth further studying and improve our current understanding of ionospheric longitude difference at midlatitude.

Zhao, Biqiang; Wang, Min; Wang, Yungang; Ren, Zhipeng; Yue, Xinan; Zhu, Jie; Wan, Weixing; Ning, Baiqi; Liu, Jing; Xiong, Bo;

Published by: Journal of Geophysical Research: Space Physics Published on: 01/2013

YEAR: 2013 DOI: 10.1029/2012JA018235

geomagnetic declination; longitudinal variation; midlatitude ionosphere

The effects of composition on thermosphere mass density response to geomagnetic activity

The ability to determine the thermosphere mass density response to geomagnetic disturbances is of critical importance in understanding how energy deposited in the thermosphere

Liu, Xianjing;

Published by: Published on:

YEAR: 2013 DOI:

Plasma Depletion Bay in the Summer Nighttime Equatorial Ionosphere

Chang, F; Liu, JG;

Published by: Published on:

YEAR: 2013 DOI:

2012

A simulation study for the couplings between DE3 tide and longitudinal WN4 structure in the thermosphere and ionosphere

Wan, W.; Ren, Z.; Ding, F.; Xiong, J.; Liu, L.; Ning, B.; Zhao, B.; Li, G.; Zhang, M.-L.;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: Jan-12-2012

YEAR: 2012 DOI: 10.1016/j.jastp.2012.04.011