Annales Geophysicae
Annales Geophysicae
ANGEO
The following lists only preprints without a corresponding final revised paper.
25 Apr 2025
Toolkit for incoherent scatter radar experiment design and applications to EISCAT_3D
Spencer Mark Hatch, Ilkka Virtanen, Karl Magnus Laundal, Habtamu Wubie Tesfaw, Juha Vierinen, Devin Ray Huyghebaert, Andres Spicher, and Jens Christian Hessen
EGUsphere, https://doi.org/10.5194/egusphere-2025-1768,https://doi.org/10.5194/egusphere-2025-1768, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
17 Apr 2025
Electron-Driven Variability of the Upper Atmospheric Nitric Oxide Column Density Over the Syowa Station in Antarctica
Pekka T. Verronen, Akira Mizuno, Yoshizumi Miyoshi, Sandeep Kumar, Taku Nakajima, Shin-Ichiro Oyama, Tomoo Nagahama, Satonori Nozawa, Monika E. Szelag, Tuomas Häkkilä, Niilo Kalakoski, Antti Kero, Esa Turunen, Satoshi Kasahara, Shoichiro Yokota, Kunihiro Keika, Tomoaki Hori, Takefumi Mitani, Takeshi Takashima, and Iku Shinohara
EGUsphere, https://doi.org/10.5194/egusphere-2025-1691,https://doi.org/10.5194/egusphere-2025-1691, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
16 Apr 2025
Radiative impact of increased middle atmospheric water vapour in the aftermath of the Hunga 2022 volcanic eruption at two locations in the Northern Hemisphere
Alistair Bell, Axel Murk, and Gunter Stober
EGUsphere, https://doi.org/10.5194/egusphere-2025-1396,https://doi.org/10.5194/egusphere-2025-1396, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
31 Mar 2025
Pre-earthquake Electric Field Disturbances and Interference Analysis Based on CSES-01 Satellite Observations
Jianping Huang, Junjie Song, Zhong Li, Wenjing Li, Hengxin Lu, Xingsu Li, Yumeng Huo, and Ruiqi Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-1013,https://doi.org/10.5194/egusphere-2025-1013, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
28 Mar 2025
Subauroral Crosstalk in POES/Metop TED Channels
Jan Maik Wissing, Olesya Yakovchuk, Stefan Bender, and Christina Arras
EGUsphere, https://doi.org/10.5194/egusphere-2025-1256,https://doi.org/10.5194/egusphere-2025-1256, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
28 Mar 2025
Effects of geomagnetic mirror force and pitch angles of precipitating electrons on ionization of the polar upper atmosphere
Tomotaka Tanaka, Yasunobu Ogawa, Yuto Katoh, Mizuki Fukizawa, Anton Artemyev, Vassilis Angelopoulos, Xiao-Jia Zhang, Yoshimasa Tanaka, and Akira Kadokura
EGUsphere, https://doi.org/10.5194/egusphere-2025-768,https://doi.org/10.5194/egusphere-2025-768, 2025
Preprint under review for ANGEO (discussion: open, 1 comment)
Short summary
26 Mar 2025
Satellite impact of Carrington-level geomagnetic storm particle fluxes and fluences
Anton Fetzer, Mikko Savola, Adnane Osmane, Vili-Arttu Ketola, Philipp Oleynik, and Minna Palmroth
EGUsphere, https://doi.org/10.5194/egusphere-2025-1279,https://doi.org/10.5194/egusphere-2025-1279, 2025
Preprint under review for ANGEO (discussion: open, 0 comments)
Short summary
21 Mar 2025
Data reduction of incoherent scatter plasma line parameters
Mini Gupta and Patrick Guio
EGUsphere, https://doi.org/10.5194/egusphere-2025-993,https://doi.org/10.5194/egusphere-2025-993, 2025
Preprint under review for ANGEO (discussion: open, 1 comment)
Short summary
25 Feb 2025
Solar wind driving of auroral outflow during a CME storm
Kai Zhao, Lynn M. Kistler, Eric J. Lund, Niloufar Nowrouzi, Christopher G. Mouikis, and Naritoshi Kitamura
EGUsphere, https://doi.org/10.5194/egusphere-2025-728,https://doi.org/10.5194/egusphere-2025-728, 2025
Preprint under review for ANGEO (discussion: final response, 2 comments)
Short summary
21 Feb 2025
Are drivers of northern lights in the ionosphere?
Osuke Saka
EGUsphere, https://doi.org/10.5194/egusphere-2025-716,https://doi.org/10.5194/egusphere-2025-716, 2025
Preprint under review for ANGEO (discussion: open, 2 comments)
Short summary
21 Feb 2025
Variations of the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
Fridrich Valach, Magdaléna Váczyová, and Eduard Koči
EGUsphere, https://doi.org/10.5194/egusphere-2025-686,https://doi.org/10.5194/egusphere-2025-686, 2025
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary
31 Jan 2025
Distinct ionospheric long-term trends in Antarctica due to the Weddell Sea Anomaly
Marayén Canales, Trinidad Duran, Manuel Bravo, Andriy Zalizovski, and Alberto Foppiano
EGUsphere, https://doi.org/10.5194/egusphere-2025-114,https://doi.org/10.5194/egusphere-2025-114, 2025
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary
31 Jan 2025
Ion beam instability model for the Mercury upstream waves
Yasuhito Narita, Daniel Schmid, and Uwe Motschmann
EGUsphere, https://doi.org/10.5194/egusphere-2025-60,https://doi.org/10.5194/egusphere-2025-60, 2025
Preprint under review for ANGEO (discussion: open, 4 comments)
Short summary
30 Jan 2025
Ionospheric Plasma Irregularities During Intense geomagnetic storms of Solar Cycle 25
Nadia Imtiaz, Andres Calabia, Chukwuma Anoruo, Aqsa Zahid, Christine Amory, and Binod Adhikari
EGUsphere, https://doi.org/10.5194/egusphere-2025-86,https://doi.org/10.5194/egusphere-2025-86, 2025
Preprint under review for ANGEO (discussion: open, 1 comment)
Short summary
28 Jan 2025
A Nonlinear Generalized Boussinesq Equation ((2+1)-D) for Rossby-Khantadze Waves
Laila Zafar Kahlon, Tamaz David Kaladze, Hassan Amir Shah, Taimoor Zaka, and Syed Assad Ul Azeem Bukhari
EGUsphere, https://doi.org/10.5194/egusphere-2025-123,https://doi.org/10.5194/egusphere-2025-123, 2025
Preprint under review for ANGEO (discussion: final response, 2 comments)
Short summary
16 Jan 2025
Modeling magnetopause location for 4D drift-resolved radiation belt codes: Salammbô model implementation
Rabia Kiraz, Nour Dahmen, Vincent Maget, and Benoit Lavraud
EGUsphere, https://doi.org/10.5194/egusphere-2024-4121,https://doi.org/10.5194/egusphere-2024-4121, 2025
Revised manuscript accepted for ANGEO (discussion: final response, 5 comments)
Short summary
14 Jan 2025
Effect of interplanetary shock waves on turbulence parameters
Emilia Kilpua, Simon Good, Juska Soljento, Domenico Trotta, Tia Bäcker, Julia Ruohotie, Jens Pomoell, Chaitanya Sishtla, and Rami Vainio
EGUsphere, https://doi.org/10.5194/egusphere-2024-3564,https://doi.org/10.5194/egusphere-2024-3564, 2025
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary
08 Jan 2025
Ozone decrease observed in the upper atmosphere following the May 11th 2024 Mother’s day solar storm
Alexandre Winant, Viviane Pierrard, and Edith Botek
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-29,https://doi.org/10.5194/angeo-2024-29, 2025
Preprint under review for ANGEO (discussion: final response, 5 comments)
Short summary
06 Jan 2025
Research on 16-day Planetary Waves in the Mid-latitude Troposphere, Stratosphere, Mesosphere, and Lower Thermosphere with Langfang Dual-frequency ST-M Radar Data
Zengmao Zhang, Xiong Hu, Qingchen Xu, Bing Cai, and Junfeng Yang
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-27,https://doi.org/10.5194/angeo-2024-27, 2025
Revised manuscript under review for ANGEO (discussion: final response, 4 comments)
Short summary
20 Dec 2024
Small- and meso-scale field-aligned auroral current structures, their spatial and temporal characteristics deduced by Swarm constellation
Hermann Lühr and Yun-Liang Zhou
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-28,https://doi.org/10.5194/angeo-2024-28, 2024
Preprint under review for ANGEO (discussion: final response, 4 comments)
Short summary
02 Dec 2024
Global evolution of flux transfer events along the magnetopause from the dayside to the far tail
Yann Pfau-Kempf, Konstantinos Papadakis, Markku Alho, Markus Battarbee, Giulia Cozzani, Lauri Pänkäläinen, Urs Ganse, Fasil Kebede, Jonas Suni, Konstantinos Horaites, Maxime Grandin, and Minna Palmroth
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-26,https://doi.org/10.5194/angeo-2024-26, 2024
Preprint under review for ANGEO (discussion: final response, 4 comments)
Short summary
02 Dec 2024
The Magnetic Vortex during a Solar Eclipse
Atef Zoughlami
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-19,https://doi.org/10.5194/angeo-2024-19, 2024
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
29 Nov 2024
First observations of continuum emission in dayside aurora
Noora Partamies, Rowan Dayton-Oxland, Katie Herlingshaw, Ilkka Virtanen, Bea Gallardo-Lacourt, Mikko Syrjäsuo, Fred Sigernes, Takanori Nishiyama, Toshi Nishimura, Mathieu Barthelemy, Anasuya Aruliah, Daniel Whiter, Lena Mielke, Maxime Grandin, Eero Karvinen, Marjan Spijkers, and Vincent Ledvina
EGUsphere, https://doi.org/10.5194/egusphere-2024-3669,https://doi.org/10.5194/egusphere-2024-3669, 2024
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary Editor-in-chief
20 Nov 2024
Study of Temperature Anisotropy and Kappa Distribution Impacts on EMIC Waves in Multi-Species Magnetized Plasma
Rahul Bhaisaniya and Ganpat Ahirwar
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-25,https://doi.org/10.5194/angeo-2024-25, 2024
Revised manuscript under review for ANGEO (discussion: final response, 12 comments)
Short summary
14 Nov 2024
Comparing Monte Carlo simulations, mean particle theory estimates, and observations of H+ and O+ outflows at high altitudes and latitudes
Imad Ahmad Barghouthi and May Rajab Halaika
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-24,https://doi.org/10.5194/angeo-2024-24, 2024
Preprint under review for ANGEO (discussion: final response, 6 comments)
Short summary
12 Nov 2024
Leaping and vortex motion of the shock aurora toward the late evening sector observed on 26 February 2023
Sota Nanjo, Masatoshi Yamauchi, Magnar Gullikstad Johnsen, Yoshihiro Yokoyama, Urban Brändström, Yasunobu Ogawa, Anna Naemi Willer, and Keisuke Hosokawa
EGUsphere, https://doi.org/10.5194/egusphere-2024-3277,https://doi.org/10.5194/egusphere-2024-3277, 2024
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary Editor-in-chief
29 Oct 2024
Deterministic chaos in modulated multi-cell drifts of localized lower hybrid oscillations excited by high frequency waves in the ionosphere
Thomas B. Leyser
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-21,https://doi.org/10.5194/angeo-2024-21, 2024
Revised manuscript accepted for ANGEO (discussion: closed, 4 comments)
Short summary
24 Oct 2024
A critical review and presentation of the complete, historic series of K-indices as determined at Norwegian Magnetic Observatories since 1939
Ingeborg Frøystein and Magnar Gullikstad Johnsen
EGUsphere, https://doi.org/10.5194/egusphere-2024-3254,https://doi.org/10.5194/egusphere-2024-3254, 2024
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary
11 Oct 2024
Predicting Geomagnetic Indices for Space Weather Applications in Solar Cycle 25
Mu He and Hongbing Zhu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-20,https://doi.org/10.5194/angeo-2024-20, 2024
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
10 Oct 2024
Estimation of the 3-D geoelectric field at the Earth's surface using Spherical Elementary Current Systems
Liisa Juusola, Heikki Vanhamäki, Elena Marshalko, Mikhail Kruglyakov, and Ari Viljanen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2831,https://doi.org/10.5194/egusphere-2024-2831, 2024
Revised manuscript accepted for ANGEO (discussion: final response, 4 comments)
Short summary
01 Oct 2024
June 21 and 25, 2015 CMEs interaction's results on Earth's ionosphere and magnetosphere
Somaiyeh Sabri and Stefaan Poedts
EGUsphere, https://doi.org/10.5194/egusphere-2024-2834,https://doi.org/10.5194/egusphere-2024-2834, 2024
Preprint under review for ANGEO (discussion: open, 1 comment)
Short summary
19 Sep 2024
First Report on Coseismic Ionospheric Disturbances Following the Deep-Focus Earthquake (Mw 6.6) in Tarauacá, Acre, Brazil: Ground Uplift and TEC Analysis
Oluwasegun M. Adebayo, Esfhan A. Kherani, and Alexandre A. Pimenta
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-16,https://doi.org/10.5194/angeo-2024-16, 2024
Revised manuscript under review for ANGEO (discussion: final response, 6 comments)
Short summary
10 Sep 2024
The impact of particle precipitation on the ion-neutral collision frequency analyzed with EISCAT measurements
Florian Günzkofer, Gunter Stober, Johan Kero, David R. Themens, Njål Gulbrandsen, Masaki Tsutsumi, and Claudia Borries
EGUsphere, https://doi.org/10.5194/egusphere-2024-2708,https://doi.org/10.5194/egusphere-2024-2708, 2024
Revised manuscript accepted for ANGEO (discussion: final response, 10 comments)
Short summary
30 Aug 2024
TIMED Doppler Interferometer Measurements of Neutral Winds at the Mesosphere and Lower Thermosphere and Comparison to Meteor Radar Winds
Arthur Gauthier, Claudia Borries, Alexander Kozlovsky, Diego Janches, Peter Brown, Denis Vida, Christoph Jacobi, Damian Murphy, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Johan Kero, Nicholas Mitchell, Tracy Moffat-Griffin, and Gunter Stober
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-13,https://doi.org/10.5194/angeo-2024-13, 2024
Preprint under review for ANGEO (discussion: final response, 4 comments)
Short summary
12 Jul 2024
Cloudiness retrieved from All-Sky camera and MSG satellite over Reunion Island and Antananarivo Madagascar
Jean-Marcel Rivonirina, Thierry Portafaix, Solofoarisoa Rakotoniaina, Béatrice Morel, Chao Tang, Kévin Lamy, Marie Lothon, Tom Toulouse, Olivier Liandrat, Solofo Rakotondraompiana, and Hassan Bencherif
EGUsphere, https://doi.org/10.5194/egusphere-2024-1827,https://doi.org/10.5194/egusphere-2024-1827, 2024
Revised manuscript under review for ANGEO (discussion: final response, 4 comments)
Short summary
17 Jun 2024
Observations of traveling ionospheric disturbances driven by gravity waves from sources in the upper and lower atmosphere
Paul Prikryl, David R. Themens, Jaroslav Chum, Shibaji Chakraborty, Robert G. Gillies, and James M. Weygand
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-6,https://doi.org/10.5194/angeo-2024-6, 2024
Preprint under review for ANGEO (discussion: final response, 10 comments)
Short summary
23 Apr 2024
Impact of solar cycle on the non-linearity of the relationship between the solar wind parameters and geomagnetic conditions
Sanni Hoilijoki, Emilia Kilpua, Adnane Osmane, Lucile Turc, Mikko Savola, Veera Lipsanen, Harriet George, and Milla Kalliokoski
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-3,https://doi.org/10.5194/angeo-2024-3, 2024
Preprint under review for ANGEO (discussion: final response, 4 comments)
Short summary
08 Mar 2024
Analysis of diurnal, seasonal and annual variations of fair weather atmospheric potential gradient at reduced number concentration of condensation nuclei from long-term measurements at Świder, Poland
Izabela Pawlak, Anna Odzimek, Daniel Kępski, and Jose Tacza
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2024-1,https://doi.org/10.5194/angeo-2024-1, 2024
Revised manuscript accepted for ANGEO (discussion: closed, 4 comments)
Short summary
13 Nov 2023
Are drivers of northern lights in the ionosphere?
Osuke Saka
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-32,https://doi.org/10.5194/angeo-2023-32, 2023
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
09 Nov 2023
Subauroral Crosstalk in POES/Metop TED proton channels
Jan Maik Wissing and Olesya Yakovchuk
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-33,https://doi.org/10.5194/angeo-2023-33, 2023
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
16 Aug 2023
A statistical study of the magnetic signatures of the unique Tonga volcanic explosion of 15 January 2022
Leonid Chernogor
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-27,https://doi.org/10.5194/angeo-2023-27, 2023
Revised manuscript not accepted (discussion: closed, 13 comments)
Short summary
28 Mar 2023
Ion’s ring current: regularities of the energy density distributions on the main phase of geomagnetic storms
Alexander Kovtyukh
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-10,https://doi.org/10.5194/angeo-2023-10, 2023
Manuscript not accepted for further review (discussion: closed, 10 comments)
Short summary
14 Mar 2023
On the set of deterministic phenomena preceding the earthquake June 25, 2021 with a magnitude of 5.4 near the city of Yayladere (Turkey)
Alexandr Volvach, Lev P. Kogan, Konstantin H. Kanonidi, Igor Bubukin, Valeria B. Shtenberg, and Larisa N. Volvach
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2023-7,https://doi.org/10.5194/angeo-2023-7, 2023
Preprint withdrawn (discussion: closed, 7 comments)
Short summary
13 Jan 2023
Bow shock characteristics from magnetic field observations
Daniel Schmid and Yasuhito Narita
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2022-30,https://doi.org/10.5194/angeo-2022-30, 2023
Revised manuscript not accepted (discussion: closed, 2 comments)
Short summary
21 Nov 2022
Asymmetric changes of maximum and minimum temperatures in the Dabie Mountains, China
Yongmei Zhao, Liyan Tang, Changming Zhu, Yuan Luo, and Fang Zhou
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2022-19,https://doi.org/10.5194/angeo-2022-19, 2022
Publication in ANGEO not foreseen (discussion: closed, 2 comments)
Short summary
05 Sep 2022
Latitudinal variations of ionospheric-thermospheric responses to Geomagnetic Storms from Multi-Instruments
Rasim Shahzad, Munawar Shah, Ayesha Abbas, Amna Hafeez, Andres Calabia, Angela Melgarejo-Morales, and Najam Abbas Naqvi
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2022-18,https://doi.org/10.5194/angeo-2022-18, 2022
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
31 Aug 2022
The solar induced 27-day modulation on polar mesospheric cloud (PMC), based on the combined observations from SOFIE and MLS
Shican Qiu, Mengzhen Yuan, Willie Soon, Victor Manuel Velasco Herrera, Zhanming Zhang, and Xiankang Dou
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2022-22,https://doi.org/10.5194/angeo-2022-22, 2022
Revised manuscript not accepted (discussion: closed, 5 comments)
Short summary
12 Nov 2021
Are drivers of northern lights in the ionosphere?
Osuke Saka
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-66,https://doi.org/10.5194/angeo-2021-66, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
01 Sep 2021
Estimation of date and magnitude of four major earthquakes using integration of precursors obtained from remote sensing data
Mohammad Mahdi Khoshgoftar and Mohammad Reza Saradjian
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-41,https://doi.org/10.5194/angeo-2021-41, 2021
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
17 Aug 2021
Automatic calculation of the magnetometer zero offset using the interplanetary magnetic field based on the Wang-Pan method
Xiaowen Hu, Guoqiang Wang, Zonghao Pan, and Tielong Zhang
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-46,https://doi.org/10.5194/angeo-2021-46, 2021
Preprint withdrawn (discussion: closed, 0 comments)
Short summary
23 Jun 2021
Latitude Oscillations of Zonal Mean Total Electron Content and Super-Fountain Effects Provided from Global GNSS Stations
Mohammad Joghataei, Niloofar Jooyandeh, and Mohammad Hossein Memarian
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-34,https://doi.org/10.5194/angeo-2021-34, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
10 Jun 2021
What caused the frequent and widespread occurrences of noctilucent clouds at middle latitudes in 2020?
Peter Dalin, Hidehiko Suzuki, Nikolay Pertsev, Vladimir Perminov, Nikita Shevchuk, Egor Tsimerinov, Mark Zalcik, Jay Brausch, Tom McEwan, Iain McEachran, Martin Connors, Ian Schofield, Audrius Dubietis, Kazimieras Černis, Alexander Zadorozhny, Andrey Solodovnik, Daria Lifatova, Jesper Grønne, Ole Hansen, Holger Andersen, Dmitry Melnikov, Alexander Manevich, Nikolay Gusev, and Vitaly Romejko
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-28,https://doi.org/10.5194/angeo-2021-28, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
19 Feb 2021
Characteristics of Ionospheric Scintillation in Chengdu, China
Song Zhang, Hailong Li, Jinghua Li, and Lin Meng
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-13,https://doi.org/10.5194/angeo-2021-13, 2021
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
17 Feb 2021
Simulation of Gravity Wave D-region disturbance and its effect on the LWPC simulated VLF signal
Abdellatif Benchafaa, Samir Nait Amor, and Ghazali Mebarki
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-68,https://doi.org/10.5194/angeo-2020-68, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
12 Feb 2021
Io's auroral emissions via global hybrid plasma simulations
Štěpán Štverák, Pavel Trávníček, Ondřej Šebek, and David Herčík
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-10,https://doi.org/10.5194/angeo-2021-10, 2021
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
25 Jan 2021
Performance of BDS B1 frequency standard point positioning during the main phase of different classes of geomagnetic storms in China and its surrounding area
Junchen Xue, Sreeja Vadakke Veettil, Marcio Aquino, Xiaogong Hu, Lin Quan, and Dun Liu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-5,https://doi.org/10.5194/angeo-2021-5, 2021
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
15 Jan 2021
A Survey on High-energy Protons Response to Geomagnetic Storm in the Inner Radiation Belt
Zhaohai He, Jiyao Xu, Ilan Roth, Chi Wang, and Lei Dai
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2021-4,https://doi.org/10.5194/angeo-2021-4, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
13 Jan 2021
Detection of Kelvin-Helmholtz billows over the National Capital Region of India using SODAR
Nishant Kumar, Kirti Soni, and Ravinder Agarwal
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-91,https://doi.org/10.5194/angeo-2020-91, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
16 Dec 2020
Dynamics of He++ ions at interplanetary shocks
Olga V. Sapunova, Natalia L. Borodkova, Georgii N. Zastenker, and Yuri I. Yermolaev
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-72,https://doi.org/10.5194/angeo-2020-72, 2020
Preprint withdrawn (discussion: closed, 6 comments)
Short summary
08 Dec 2020
Requirement of HE-PIXE at High Z Elements in Charnockite Matrix Composition
Avupati Venkata Surya Satyanarayana, Mokka Jagannadha Rao, and Byreddy Seetharami Reddy
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-77,https://doi.org/10.5194/angeo-2020-77, 2020
Preprint withdrawn (discussion: closed, 0 comments)
Short summary
08 Dec 2020
Neutral air turbulence in the mesosphere and associated polar mesospheric summer echoes (PMSEs)
Alireza Mahmoudian, Mike J. Kosch, Wayne A. Scales, Michael T. Rietveld, and Henry Pinedo
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-81,https://doi.org/10.5194/angeo-2020-81, 2020
Preprint withdrawn (discussion: closed, 7 comments)
Short summary
04 Dec 2020
Comment on Invariability of relationship between the polar cap magnetic activity and geoeffective interplanetary electric field by Troshichev et al. (2011)
Peter Stauning
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-52,https://doi.org/10.5194/angeo-2020-52, 2020
Preprint withdrawn (discussion: closed, 5 comments)
Short summary
27 Nov 2020
Thermal electron anisotropy driven by kinetic Alfven waves in the Earth's magnetotail
Alexander Lukin, Anton Artemyev, Evgeny Panov, Rumi Nakamura, Anatoly Petrukovich, Robert Ergun, Barbara Giles, Yuri Khotyaintsev, Per Arne Lindqvist, Christopher Russell, and Robert Strangeway
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-76,https://doi.org/10.5194/angeo-2020-76, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
21 Sep 2020
Dynamic Spectra of Small-Mass Meteors
Emma R. Mirizio, Robert G. Michell, and Marilia Samara
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-61,https://doi.org/10.5194/angeo-2020-61, 2020
Revised manuscript not accepted (discussion: closed, 5 comments)
Short summary
01 Jul 2020
Validation of CAMS AOD using AERONET Data and Trend Analysis at Four Locations in the Indo-Gangetic Basin
Amit Misra, Sachchida Tripathi, Harjinder Sembhi, and Hartmut Boesch
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-40,https://doi.org/10.5194/angeo-2020-40, 2020
Publication in ANGEO not foreseen (discussion: closed, 2 comments)
Short summary
25 May 2020
Variability of Relativistic Electron Flux (E > 2 MeV) during Geo-Magnetically Quiet and Disturbed days: A Case Study
Tulsi Thapa, Binod Adhikari, Prashrit Baruwal, and Kiran Pudasainee
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-35,https://doi.org/10.5194/angeo-2020-35, 2020
Preprint withdrawn (discussion: closed, 4 comments)
20 Apr 2020
Earth-like planetary magnetotails as non-linear oscillators
Robert J. Burston
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-12,https://doi.org/10.5194/angeo-2020-12, 2020
Publication in ANGEO not foreseen (discussion: closed, 6 comments)
02 Mar 2020
Ionospheric total electron content anomaly possibly associated with the April 4, 2010 Mw7.2 Mexico earthquake
Jing Liu, Wenbin Wang, and Xuemin Zhang
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2020-5,https://doi.org/10.5194/angeo-2020-5, 2020
Manuscript not accepted for further review (discussion: closed, 5 comments)
Short summary
02 Jan 2020
Inferring the source regions of pulsating auroras
Eric Grono and Eric Donovan
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-162,https://doi.org/10.5194/angeo-2019-162, 2020
Preprint withdrawn (discussion: closed, 3 comments)
Short summary
03 Dec 2019
Geomagnetic pulsations in the Pc5/Pi3 frequency range and fluctuations of foF2 frequency
Nadezda Yagova, Alexander Kozlovsky, Evgeny Fedorov, and Olga Kozyreva
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-155,https://doi.org/10.5194/angeo-2019-155, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
29 Nov 2019
On the correlation between ROTI and S4
Yang Liu and Sandro Radicella
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-147,https://doi.org/10.5194/angeo-2019-147, 2019
Publication in ANGEO not foreseen (discussion: closed, 2 comments)
Short summary
25 Nov 2019
Nighttime O(1D) distributions in the mesopause region derived from SABER data
Mikhail Yu. Kulikov and Mikhail V. Belikovich
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-154,https://doi.org/10.5194/angeo-2019-154, 2019
Manuscript not accepted for further review (discussion: closed, 2 comments)
05 Nov 2019
Automatic detection of the Earth Bow Shock and Magnetopause from in-situ data with machine learning
Gautier Nguyen, Nicolas Aunai, Bayane Michotte de Welle, Alexis Jeandet, and Dominique Fontaine
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-149,https://doi.org/10.5194/angeo-2019-149, 2019
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
18 Sep 2019
Ionospheric Plasma Density Measurements by Swarm Langmuir Probes: Limitations and possible Corrections
Piero Diego, Igino Coco, Igor Bertello, Maurizio Candidi, and Pietro Ubertini
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-136,https://doi.org/10.5194/angeo-2019-136, 2019
Manuscript not accepted for further review (discussion: closed, 10 comments)
Short summary
18 Sep 2019
Intercomparison of FY-3 and AIRS Gravity Wave Parameter Extraction Based on Three Methods
Shujie Chang, Zheng Sheng, Wei Ge, Wei Zhang, Yang He, and Zhixian Luo
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-130,https://doi.org/10.5194/angeo-2019-130, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
09 Sep 2019
A case study of the day-to-day occurrence of plasma irregularities in low-latitude ionosphere from multi-satellite observations
Weihua Luo, Chao Xiong, Zhengping Zhu, Shanshan Chang, and Xiao Yu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-128,https://doi.org/10.5194/angeo-2019-128, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
26 Aug 2019
Using the Galilean Relativity Principle to Understand the Physical Basis for Magnetosphere-Ionosphere Coupling Processes
Anthony J. Mannucci, Ryan McGranaghan, Xing Meng, Bruce T. Tsurutani, and Olga P. Verkhoglyadova
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-108,https://doi.org/10.5194/angeo-2019-108, 2019
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
02 Jul 2019
Air Density Induced Error on Wind Energy Estimation
Aurore Dupré, Philippe Drobinski, Jordi Badosa, Christian Briard, and Riwal Plougonven
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-88,https://doi.org/10.5194/angeo-2019-88, 2019
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
01 Jul 2019
Density correction of NRLMSISE-00 in the middle atmosphere (20–100 km) based on TIMED/SABER density data
Xuan Cheng, Junfeng Yang, Cunying Xiao, and Xiong Hu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-93,https://doi.org/10.5194/angeo-2019-93, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
13 Jun 2019
Invariants of the Spatial-Energy Structure and Modeling of the Earth's Ion Radiation Belts
Alexander S. Kovtyukh
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-82,https://doi.org/10.5194/angeo-2019-82, 2019
Revised manuscript not accepted (discussion: closed, 12 comments)
Short summary
12 Jun 2019
Combinatorial observation ionospheric characteristics during tropical cyclone Debbie passing eastern Australia in 2017 using GPS and ion sounder
Fuyang Ke, Jinling Wang, Kehe Wang, Jiujing Xu, Yong Wang, Xinzhi Wang, and Jian Deng
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-72,https://doi.org/10.5194/angeo-2019-72, 2019
Preprint withdrawn (discussion: closed, 9 comments)
Short summary
23 May 2019
The Present & Future of the Brazilian INPE-UFSM NANOSATC-BR, CubeSats Development Program
Nelson J. Schuch, Rodrigo P. Marques, Otávio S. C. Durão, Marlos R. da Silva, Odim Mendes, Fátima Mattiello-Francisco, Andrei P. Legg, André L. da Silva, Fernando S. Pedroso, and Eduardo E. Bürger
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-58,https://doi.org/10.5194/angeo-2019-58, 2019
Preprint withdrawn (discussion: closed, 2 comments)
Short summary
09 May 2019
Long Range Plasma Momentum Coupling by High Voltage Static Electric field and Deep Space Exploration
Kokwei Chew, Xinyu Zhou, and Yian Lei
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-41,https://doi.org/10.5194/angeo-2019-41, 2019
Manuscript not accepted for further review (discussion: closed, 5 comments)
Short summary
26 Apr 2019
Characteristics of ionospheric irregularities near the northern equatorial anomaly crest
Jinghua Li, Guanyi Ma, Klemens Hocke, Qingtao Wan, Jiangtao Fan, and Xiaolan Wang
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-64,https://doi.org/10.5194/angeo-2019-64, 2019
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
15 Apr 2019
Investigation of Effects of Coronal Mass Ejections on Ionospheric Total Electron Content over Nsukka, South Eastern Nigeria
Esther A. Hanson, F. Nneka Okeke, and Kingsley Okpala
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-39,https://doi.org/10.5194/angeo-2019-39, 2019
Publication in ANGEO not foreseen (discussion: closed, 4 comments)
14 Mar 2019
Variation in altitude of high-frequency enhanced plasma line by the pump near the 5th electron gyro-harmonic
Jun Wu, Jian Wu, Michael T. Rietveld, Ingemar Haggstrom, Haisheng Zhao, Tong Xu, and Zhengwen Xu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-23,https://doi.org/10.5194/angeo-2019-23, 2019
Manuscript not accepted for further review (discussion: closed, 6 comments)
06 Mar 2019
The linear growth rate of Rayleigh–Taylor instability in ionospheric F layer
Kangkang Liu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-28,https://doi.org/10.5194/angeo-2019-28, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
27 Feb 2019
Effects of Earth's magnetic field variation on high frequency wave propagation in the ionosphere
Mariano Fagre, Bruno S. Zossi, Erdal Yiğit, Hagay Amit, and Ana G. Elias
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-27,https://doi.org/10.5194/angeo-2019-27, 2019
Preprint retracted (discussion: closed, 4 comments)
Short summary
25 Jan 2019
Analysis of geomagnetic measurements prior the Maule (2010), Iquique (2014) and Illapel (2015) earthquakes, in the Pacific Ocean sector of the Southern Hemisphere
Enrique G. Cordaro, Patricio Venegas-Aravena, and David Laroze
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-9,https://doi.org/10.5194/angeo-2019-9, 2019
Manuscript not accepted for further review (discussion: closed, 7 comments)
Short summary
24 Jan 2019
Decrease of total electron content during the 9 March 2016 total solar eclipse observed at low latitude stations, Indonesia
Wahyu Srigutomo, Alamta Singarimbun, Winda Meutia, I Gede Putu Fadjar Soerya Djaja, Buldan Muslim, and Prayitno Abadi
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2019-11,https://doi.org/10.5194/angeo-2019-11, 2019
Publication in ANGEO not foreseen (discussion: closed, 4 comments)
Short summary
12 Dec 2018
Regional Ionosphere Mapping Using Zero Difference GPS Carrier Phase
Heba Tawfeek, Ahmed Sedeek, Mostafa Rabah, and Gamal El-Fiky
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-121,https://doi.org/10.5194/angeo-2018-121, 2018
Publication in ANGEO not foreseen (discussion: closed, 2 comments)
06 Dec 2018
The current sheet flapping motions induced by non-adiabatic ions: case study
Xinhua Wei, Chunlin Cai, Henri Rème, Iannis Dandouras, and George Parks
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-124,https://doi.org/10.5194/angeo-2018-124, 2018
Revised manuscript not accepted (discussion: closed, 10 comments)
Short summary
15 Nov 2018
Non-linear Effects in Electromagnetic Wave Activity Observed in the RELEC Experiment on-board Vernov Mission
Mikhail I. Panasyuk, Sergey I. Svertilov, Stanislav I. Klimov, Valery A. Grushin, Denis I. Novikov, Yuri Y. Ruzhin, Yuri M. Mikhailov, Csaba Ferencz, Peter Szegedi, Valery E. Korepanov, Vitaly V. Bogomolov, Gali K. Garipov, Serhiy V. Belyayev, and Olexander N. Demidov
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-119,https://doi.org/10.5194/angeo-2018-119, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
14 Nov 2018
Statistical variations of lower atmospheric turbulence and roles of inertial gravity waves at a middle latitude radiosonde site
Jian Zhang, Shao Dong Zhang, Chun Ming Huang, Kai Ming Huang, Ye Hui Zhang, Yun Gong, and Quan Gan
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-114,https://doi.org/10.5194/angeo-2018-114, 2018
Publication in ANGEO not foreseen (discussion: closed, 2 comments)
Short summary
30 Oct 2018
A combined analysis of geomagnetic data and cosmic ray secondaries in the September 2017 space weather phenomena studies
Roman Sidorov, Anatoly Soloviev, Alexei Gvishiani, Viktor Getmanov, Mioara Mandea, Anatoly Petrukhin, and Igor Yashin
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-111,https://doi.org/10.5194/angeo-2018-111, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
25 Oct 2018
Vertical Ionosphere Delay Estimation using Zero Difference GPS Phase Observation
Ahmed Elsayed, Ahmed Sedeek, Mohamed Doma, and Mostafa Rabah
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-113,https://doi.org/10.5194/angeo-2018-113, 2018
Preprint withdrawn (discussion: closed, 3 comments)
Short summary
18 Oct 2018
Characteristic study of double substorm onsets in response to IMF variations
Ching-Chang Cheng, Christopher T. Russell, Ian R. Mann, Eric Donovan, and Wolfgang Baumjohann
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-116,https://doi.org/10.5194/angeo-2018-116, 2018
Preprint withdrawn (discussion: closed, 3 comments)
Short summary
28 Sep 2018
Wave activity in front of high-β Earth bow shocks
Anatoli A. Petrukovich, Olga M. Chugunova, and Pavel I. Shustov
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-110,https://doi.org/10.5194/angeo-2018-110, 2018
Manuscript not accepted for further review (discussion: closed, 5 comments)
Short summary
06 Sep 2018
Semiannual Variation in radiation belts particle fluxes: Van Allen probes observations
Facundo L. Poblet and Francisco Azpilicueta
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-98,https://doi.org/10.5194/angeo-2018-98, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
30 Aug 2018
Evaluation of the IGS–Global Ionospheric Mapping model over Egypt
Mostafa Rabah and Ahmed Sedeek
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-92,https://doi.org/10.5194/angeo-2018-92, 2018
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
29 Aug 2018
Improvements to Predictions of the Ionospheric Annual Anomaly by the International Reference Ionosphere Model
Steven Brown, Dieter Bilitza, and Erdal Yiğit
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-97,https://doi.org/10.5194/angeo-2018-97, 2018
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
24 Aug 2018
Variation in total electron content with sunspot number during the ascending and maximum phases of solar cycle 24 at Birnin Kebbi
Aghogho Ogwala, Emmanuel Olufemi Somoye, Olugbenga Ogunmodimu, Rasaq Adewemimo Adeniji-Adele, Eugene Oghenakpobo Onori, Oluwole Oyedokun, and Ernest Iheonu
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-95,https://doi.org/10.5194/angeo-2018-95, 2018
Manuscript not accepted for further review (discussion: closed, 9 comments)
Short summary
23 Jul 2018
Capturing the signature of heavy rainfall events using the 2-d-/4-d water vapour information derived from GNSS measurement in Hong Kong
Qingzhi Zhao, Yibin Yao, and Wanqiang Yao
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-76,https://doi.org/10.5194/angeo-2018-76, 2018
Manuscript not accepted for further review (discussion: closed, 8 comments)
Short summary
17 Jul 2018
Dependence of the critical Richardson number on the temperature gradient in the mesosphere
Michael N. Vlasov and Michael C. Kelley
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-71,https://doi.org/10.5194/angeo-2018-71, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
19 Jun 2018
Singular variations in geomagnetic disturbance content at auroral latitudes
Abraham Abraham, Gangadharan Renuka, Cherian Ligi, Joseph Mathew Tiju, Anie Varghese Asha, S. B. Chandran Rakesh, and Varghese Blessy
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-62,https://doi.org/10.5194/angeo-2018-62, 2018
Preprint withdrawn (discussion: closed, 2 comments)
Short summary
07 Jun 2018
On the directions and structure of the short-term magnetic variations
Andrey Khokhlov, Roman Krasnoperov, Bogdan Nikolov, Julia Nikolova, Mikhail Dobrovolsky, Dmitry Kudin, Valery Petrov, and Ivan Belov
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-46,https://doi.org/10.5194/angeo-2018-46, 2018
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
05 Jun 2018
Variability of TEC and improvement of performance of the IRI model over Ethiopia during the high solar activity phase
Yekoye Asmare Tariku
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-48,https://doi.org/10.5194/angeo-2018-48, 2018
Preprint retracted (discussion: closed, 5 comments)
30 May 2018
Contribution of patchy reconnection to the ion to electron temperature ratio in the Earth's magnetotail
Chuxin Chen and Chih-Ping Wang
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-47,https://doi.org/10.5194/angeo-2018-47, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
16 Feb 2018
Monitoring potential ionosphere changes caused by Van earthquake (Mw 7.2) using GNSS measurements
Selcuk Peker, Samed Inyurt, and Cetin Mekik
Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-11,https://doi.org/10.5194/angeo-2018-11, 2018
Preprint retracted (discussion: closed, 4 comments)
CC BY 4.0