{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:18:51Z","timestamp":1760145531843,"version":"build-2065373602"},"reference-count":57,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T00:00:00Z","timestamp":1723420800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["41831073"],"award-info":[{"award-number":["41831073"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This study investigates the latitudinal characteristics of the nighttime electron temperature, as observed by the Defense Meteorological Satellite Program F16 satellite, and its dependence on solar and geomagnetic activities between 2013 and 2022 in the topside ionosphere, only for the winter hemispheres. The electron temperature in both hemispheres exhibited a low-temperature zone at the equator and a double high-temperature zone at the sub-auroral and auroral latitudes along the magnetic latitude. In addition, we further studied the temperature crest\/trough positions in the temperature zone at different latitudes. As the solar activity intensity decreased (increased), the temperature trough position at the equator shifted from the Southern (Northern) to the Northern (Southern) Hemisphere, and the temperature double-crest positions at the sub-auroral and auroral latitudes gradually approached (moved away from) each other. Furthermore, during the geomagnetic disturbance time, the temperature double-crest positions both moved toward lower latitudes, but the temperature trough position was not sensitive to geomagnetic activity. Our analysis demonstrates that the values and correlations of the electron temperature and density varied in different temperature characteristic zones (the temperature crest\/trough positions \u00b12\u00b0), possibly due to the different energy control factors of the electrons at different latitudes. This may also indirectly indicate the energy coupling process between the topside ionosphere and different regions at different latitudes.<\/jats:p>","DOI":"10.3390\/rs16162946","type":"journal-article","created":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T08:54:08Z","timestamp":1723452848000},"page":"2946","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Latitudinal Characteristics of Nighttime Electron Temperature in the Topside Ionosphere and Its Dependence on Solar and Geomagnetic Activities"],"prefix":"10.3390","volume":"16","author":[{"given":"Jianyun","family":"Liang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100090, China"},{"name":"College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiyao","family":"Xu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100090, China"},{"name":"College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kun","family":"Wu","sequence":"additional","affiliation":[{"name":"High Altitude Observatory, NSF National Center for Atmospheric Research, Boulder, CO 80301, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ji","family":"Luo","sequence":"additional","affiliation":[{"name":"College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Schunk, R.W., and Nagy, A.F. (2009). Ionospheres: Physics, Plasma Physics, and Chemistry, Cambridge University Press. [2nd ed.].","DOI":"10.1017\/CBO9780511635342"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"11203","DOI":"10.1029\/JA091iA10p11203","article-title":"Dual-spacecraft measurements of plasmasphere-ionosphere coupling","volume":"91","author":"Horwitz","year":"1986","journal-title":"J. Geophys. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/0273-1177(95)00904-3","article-title":"Spatial and temporal variations of the electron temperature at equatorial anomaly latitudes","volume":"18","author":"Su","year":"1996","journal-title":"Adv. Space Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"A01304","DOI":"10.1029\/2009JA014334","article-title":"Predawn ionospheric heating observed by Hinotori satellite","volume":"115","author":"Kakinami","year":"2010","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1187","DOI":"10.1029\/2002GL016268","article-title":"Presunrise ion temperature enhancement observed at 600 km low- and mid-latitude ionosphere","volume":"30","author":"Chao","year":"2003","journal-title":"Geophys. Res. Lett."},{"key":"ref_6","first-page":"A09304","article-title":"Modeling the presunrise plasma heating in the low-to midlatitude topside ionospheres","volume":"115","author":"Chao","year":"2010","journal-title":"J. Geophys. Res."},{"key":"ref_7","first-page":"A11301","article-title":"A numerical study of the response of ionospheric electron temperature to geomagnetic activity","volume":"111","author":"Wang","year":"2006","journal-title":"J. Geophys. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e2021JA030121","DOI":"10.1029\/2021JA030121","article-title":"Simultaneous detection of signatures of conjugate photoelectrons in the ionosphere and thermosphere","volume":"127","author":"Kil","year":"2022","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"L05108","DOI":"10.1029\/2007GL032998","article-title":"Longitudinal variations of electron temperature and total ion density in the sunset equatorial topside ionosphere","volume":"35","author":"Ren","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"959","DOI":"10.5636\/jgg.48.959","article-title":"Morning overshoot of Te enhanced by downward plasma drift in the equatorial topside ionosphere","volume":"48","author":"Oyama","year":"1996","journal-title":"J. Geomagn. Geoelectr."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"20705","DOI":"10.1029\/98JA01748","article-title":"Plasma temperature variations in the ionosphere over the middle and upper atmosphere radar","volume":"103","author":"Otsuka","year":"1998","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_12","first-page":"A04308","article-title":"Solar flux variation of the electron temperature morning overshoot in the equatorial F region","volume":"116","author":"Stolle","year":"2011","journal-title":"J. Geophys. Res."},{"key":"ref_13","first-page":"163","article-title":"Diurnal variation of electron and ion temperatures with altitude","volume":"4","author":"Alexander","year":"2014","journal-title":"Int. J. Appl. Sci. Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e2019JA027299","DOI":"10.1029\/2019JA027299","article-title":"Morning overshoot of electron temperature as observed by the Swarm constellation and the International Space Station","volume":"125","author":"Yang","year":"2020","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1029\/JA078i004p00751","article-title":"Ogo-6 measurements of super cooled plasma in the equatorial exosphere","volume":"78","author":"Hanson","year":"1973","journal-title":"J. Geophys. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1029\/96JA02705","article-title":"High electron temperature associated with the prereversal enhancement in the equatorial ionosphere","volume":"102","author":"Oyama","year":"1997","journal-title":"J. Geophys. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2747","DOI":"10.5194\/angeo-22-2747-2004","article-title":"Comparison of the measured and modelled electron densities, and electron and ion temperatures in the low-latitude ionosphere during 12\u201321 March 1988","volume":"22","author":"Pavlov","year":"2004","journal-title":"Ann. Geophys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7269","DOI":"10.1002\/2015JA022317","article-title":"Variation of the topside ionosphere during the last solar minimum period studied with multi satellite measurements of electron density and temperature","volume":"121","author":"Ryu","year":"2016","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"7485","DOI":"10.1029\/97JA00039","article-title":"A plasma temperature anomaly in the equatorial topside ionosphere","volume":"102","author":"Balan","year":"1997","journal-title":"J. Geophys. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e2023JA031513","DOI":"10.1029\/2023JA031513","article-title":"Global distribution of electron temperature enhancement at mid-low latitudes observed by DMSP F16 satellite","volume":"128","author":"Liang","year":"2023","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e2019GL086383","DOI":"10.1029\/2019GL086383","article-title":"The far ultraviolet signatures of conjugate photoelectrons seen by the Special Sensor Ultraviolet Spectrographic Imager","volume":"47","author":"Kil","year":"2020","journal-title":"Geophys. Res. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1861","DOI":"10.1029\/90JA02377","article-title":"Solar cycle variation in the subauroral electron temperature enhancement: Comparison of AE-C and DE 2 satellite observations","volume":"96","author":"Fok","year":"1991","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1871","DOI":"10.5194\/angeo-24-1871-2006","article-title":"Subauroral electron temperature enhancement in the nighttime ionosphere","volume":"24","author":"Prolss","year":"2006","journal-title":"Ann. Geophys."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"807","DOI":"10.5194\/angeo-20-807-2002","article-title":"Diurnal, seasonal and latitudinal variations of electron temperature measured by the SROSS C2 satellite at 500 km altitude and comparison with the IRI","volume":"20","author":"Bhuyan","year":"2002","journal-title":"Ann. Geophys."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1995","DOI":"10.5194\/angeo-25-1995-2007","article-title":"Diurnal, seasonal, latitudinal and solar cycle variation of electron temperature in the topside f-region of the indian zone ionosphere","volume":"25","author":"Chamua","year":"2007","journal-title":"Ann. Geophys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/j.jastp.2004.09.004","article-title":"Diurnal, seasonal and latitudinal variations of ionospheric temperatures of the topside f region over the indian region during solar minimum (1995\u20131996)","volume":"67","author":"Sharma","year":"2005","journal-title":"J. Atmos. Solar-Terr. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"14581","DOI":"10.1029\/95JA01356","article-title":"Computer simulations of electron and ion densities and temperatures in the equatorial F region and comparison with Hinotori results","volume":"100","author":"Watanabe","year":"1996","journal-title":"J. Geophys. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1016\/j.asr.2003.07.012","article-title":"Ionospheric plasma temperatures during 1976\u20132001 over Millstone Hill","volume":"33","author":"Zhang","year":"2004","journal-title":"Adv. Space Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"A02302","DOI":"10.1029\/2006JA012041","article-title":"Electron temperature climatology at Millstone Hill and Arecibo","volume":"112","author":"Lei","year":"2007","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1016\/j.asr.2006.11.022","article-title":"Solar cycle variations of mid-latitude electron density and temperature: Satellite measurements and model calculations","volume":"39","author":"Bilitza","year":"2007","journal-title":"Adv. Space Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1016\/j.asr.2009.04.029","article-title":"Latitudinal variation of the topside electron temperature at different levels of solar activity","volume":"44","author":"Truhlik","year":"2009","journal-title":"Adv. Space Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2055","DOI":"10.1016\/j.jastp.2009.09.013","article-title":"Variations of daytime and nighttime electron temperature and heat flux in the upper ionosphere, topside ionosphere and lower plasmasphere for low and high solar activity","volume":"71","author":"Truhlik","year":"2009","journal-title":"J. Atmos. Solar-Terr. Phys."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Pignalberi, A., Truhlik, V., Giannattasio, F., Coco, I., and Pezzopane, M. (2024). Mid- and High-Latitude Electron Temperature Dependence on Solar Activity in the Topside Ionosphere through the Swarm B Satellite Observations and the International Reference Ionosphere Model. Atmosphere, 15.","DOI":"10.3390\/atmos15040490"},{"key":"ref_34","unstructured":"Delorey, D.E., Pruneau, P.N., and Parsons, C.M. (1989). Database Development for the DMSP SSIES Experiment, Air Force Geophysics Laboratory, Hanscom Air Force Base. Technical Report GL-TR-89-0066."},{"key":"ref_35","first-page":"284","article-title":"Ionospheric Techniques and Phenomena","volume":"13","author":"Giraud","year":"1978","journal-title":"Geophys. Astrophys. Monogr."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e2022RG000792","DOI":"10.1029\/2022RG000792","article-title":"The International Reference Ionosphere model: A review and description of an ionospheric benchmark","volume":"60","author":"Bilitza","year":"2022","journal-title":"Rev. Geophys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/0273-1177(85)90193-0","article-title":"Implementation of the new electron temperature model in IRI","volume":"5","author":"Bilitza","year":"1985","journal-title":"Adv. Space Res."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1317","DOI":"10.1016\/0021-9169(81)90157-4","article-title":"Global empirical models of ionospheric electron temperature in the upper F-region and plasmasphere based on in situ measurements from atmosphere explorer C, ISIS 1 and ISIS 2 satellites","volume":"43","author":"Brace","year":"1981","journal-title":"J. Atmos. Terr. Phys."},{"key":"ref_39","first-page":"43","article-title":"Empirical model of global electron temperature distribution between 300 and 700 km based on data from AEROS-A","volume":"46","author":"Spenner","year":"1979","journal-title":"J. Geophys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"531","DOI":"10.5047\/eps.2011.10.016","article-title":"A new global empirical model of the electron temperature with inclusion of the solar activity variations for IRI","volume":"64","author":"Truhlik","year":"2012","journal-title":"Earth Planets Space"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2124","DOI":"10.1016\/j.asr.2020.11.012","article-title":"A solar activity correction term for the IRI topside electron density model","volume":"68","author":"Bilitza","year":"2021","journal-title":"Adv. Space Res."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Pignalberi, A., Giannattasio, F., Truhlik, V., Coco, I., Pezzopane, M., Consolini, G., De Michelis, P., and Tozzi, R. (2021). On the Electron Temperature in the Topside Ionosphere as Seen by Swarm Satellites, Incoherent Scatter Radars, and the International Reference Ionosphere Model. Remote Sens., 13.","DOI":"10.3390\/rs13204077"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1016\/j.asr.2006.06.013","article-title":"Topside sounder model of scale height and transition height characteristics of the ionosphere","volume":"39","author":"Kutiev","year":"2007","journal-title":"Adv. Space Res."},{"key":"ref_44","first-page":"A11306","article-title":"Solar activity variations of nighttime ionospheric peak electron density","volume":"113","author":"Chen","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1029\/RG016i003p00355","article-title":"Electron temperatures in the F region ionosphere: Theory and observations","volume":"16","author":"Schunk","year":"1978","journal-title":"Rev. Geophys. Space Phys."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1007\/s00585-996-0290-5","article-title":"Effects of neutral wind on the electron temperature at a height of 600 km in the low latitude region","volume":"14","author":"Watanabe","year":"1996","journal-title":"Ann. Geophys."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"10737","DOI":"10.1029\/95JA03516","article-title":"Morphology of nightside precipitation","volume":"101","author":"Newell","year":"1996","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1453","DOI":"10.1016\/0032-0633(89)90115-3","article-title":"Electron temperature structure around mid-latitude ionospheric trough","volume":"37","author":"Watanabe","year":"1989","journal-title":"Planet. Space Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"10724","DOI":"10.1002\/2015JA021303","article-title":"The correlation between electron temperature and density in the topside ionosphere during 2006\u20132009","volume":"120","author":"Su","year":"2015","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"e2023JA032201","DOI":"10.1029\/2023JA032201","article-title":"Investigating the main features of the correlation between electron density and temperature in the topside ionosphere through Swarm satellites data","volume":"129","author":"Pignalberi","year":"2024","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2893","DOI":"10.5194\/angeo-27-2893-2009","article-title":"WN4 effect on longitudinal distribution of different ion species in the topside ionosphere at low latitudes by means of DEMETER, DMSP-F13 and DMSP-F15 data","volume":"27","author":"Bankov","year":"2009","journal-title":"Ann. Geophys."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"5917","DOI":"10.1029\/2017JA024840","article-title":"The midlatitude trough and the plasmapause in the nighttime ionosphere simultaneously observed by DEMETER during 2006\u20132009","volume":"123","author":"Chen","year":"2018","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1186\/s40623-015-0365-1","article-title":"Statistical analysis of ionospheric mid-latitude trough over the northern hemisphere derived from GPS total electron content data","volume":"67","author":"Yang","year":"2015","journal-title":"Earth Planets Space"},{"key":"ref_54","first-page":"31","article-title":"Statistical study on the occurrence of the ionospheric mid-latitude trough and the variation of trough minimum location over northern hemisphere","volume":"63","author":"He","year":"2020","journal-title":"Chin. J. Geophys."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"8039","DOI":"10.1029\/2019JA026631","article-title":"Variations in the winter troughs\u2019 position with local time, longitude, and solar activity in the Northern and Southern Hemispheres","volume":"124","author":"Karpachev","year":"2019","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"7949","DOI":"10.1029\/JA095iA06p07949","article-title":"Plasmasphere-ionosphere coupling: 2. ion composition measurements at plasmaspheric and ionospheric altitudes and comparison with modeling results","volume":"95","author":"Horwitz","year":"1990","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1007\/BF00879813","article-title":"A mathematical model of the middle and high latitude ionosphere","volume":"127","author":"Schunk","year":"1988","journal-title":"Pure Appl. Geophys."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/16\/2946\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:35:02Z","timestamp":1760110502000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/16\/2946"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,12]]},"references-count":57,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["rs16162946"],"URL":"https:\/\/doi.org\/10.3390\/rs16162946","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2024,8,12]]}}}