Journal of Geophysical Research: Space Physics最新文献

{"title":"The Role of the Polar Vortex Jet for Secondary and Higher-Order Gravity Waves in the Northern Mesosphere and Thermosphere During 11–14 January 2016","authors":"Sharon L. Vadas,&nbsp;Erich Becker,&nbsp;Katrina Bossert,&nbsp;Yuta Hozumi,&nbsp;Gunter Stober,&nbsp;V. Lynn Harvey,&nbsp;Gerd Baumgarten,&nbsp;Lars Hoffmann","doi":"10.1029/2024JA032521","DOIUrl":"https://doi.org/10.1029/2024JA032521","url":null,"abstract":"<p>We analyze the gravity waves (GWs) from the ground to the thermosphere during 11–14 January 2016 using the nudged HI Altitude Mechanistic general Circulation Model. We find that the entrance, core and exit regions of the polar vortex jet are important for generating primary GWs and amplifying GWs from below. These primary GWs dissipate in the upper stratosphere/lower mesosphere and deposit momentum there; the atmosphere responds by generating secondary GWs. This process is repeated, resulting in medium to large-scale higher-order, thermospheric GWs. We find that the amplitudes of the secondary/higher-order GWs from sources below the polar vortex jet are exponentially magnified. The higher-order, thermospheric GWs have concentric ring, arc-like and planar structures, and spread out latitudinally to 10 − 90°N. Those GWs with the largest amplitudes propagate against the background wind. Some of the higher-order GWs generated over Europe propagate over the Arctic region then southward over the US to ∼15–20°N daily at ∼14 − 24 UT (∼9 − 16 LT) due to the favorable background wind. These GWs have horizontal wavelengths <i>λ</i>_<i>H</i> ∼ 200 − 2,200 km, horizontal phase speeds <i>c</i>_<i>H</i> ∼ 165 − 260 m/s, and periods <i>τ</i>_<i>r</i> ∼ 0.3 − 2.4 hr. Such GWs could be misidentified as being generated by auroral activity. The large-scale, higher-order GWs are generated in the lower thermosphere and propagate southwestward daily across the northern mid-thermosphere at ∼8–16 LT with <i>λ</i>_<i>H</i> ∼ 3,000 km and <i>c</i>_<i>H</i> ∼ 650 m/s. We compare the simulated GWs with those observed by AIRS, VIIRS/DNB, lidar and meteor radars and find reasonable to good agreement. Thus the polar vortex jet is important for facilitating the global generation of medium to large-scale, higher-order thermospheric GWs via multi-step vertical coupling.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization and \u0000 \u0000 \u0000 m\u0000 \u0000 $m$\u0000 -Number Characteristics of Mid-Latitude Pc5 ULF Waves Observed by SuperDARN Radars","authors":"K. Morita,&nbsp;P. Ponomarenko,&nbsp;N. Nishitani,&nbsp;T. Hori,&nbsp;S. G. Shepherd","doi":"10.1029/2024JA032592","DOIUrl":"https://doi.org/10.1029/2024JA032592","url":null,"abstract":"<p>Polarization and propagation characteristics of ultra-low frequency (ULF, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≃</mo>\u0000 <mn>1</mn>\u0000 <mo>−</mo>\u0000 <mn>1000</mn>\u0000 </mrow>\u0000 <annotation> $simeq 1-1000$</annotation>\u0000 </semantics></math> mHz) waves are conventionally studied using arrays of ground-based magnetometers. However, the ground magnetometer observations are subject to distortions due to polarization rotation and spatial integration effects caused by the transition of the magnetohydrodynamic wave into an electromagnetic wave at the lower ionospheric boundary. In contrast, high-frequency (3–30 MHz) radars, like those comprising the Super Dual Auroral Radar Network (SuperDARN), are capable of direct observations of the ULF wave characteristics at ionospheric altitudes via measuring plasma drift velocity variations caused by the wave's electric field. In this work, we use multi-beam data from SuperDARN Hokkaido East, Hokkaido West, and Christmas Valley West radars to identify the dominant polarization modes as well as azimuthal wave numbers of evening-night-side-morning ULF waves in the Pc5 frequency band (1.67–6.67 mHz) propagating over sub-auroral and mid-latitude regions. The observed statistical characteristics of these waves point at the solar wind dynamic pressure variations and Kelvin-Helmholtz instability at the magnetopause as their potential principal sources, although the drift-bounce resonance with trapped energetic ions may contribute to the small-scale part of the observed Pc5 wave population.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whistler-Mode Waves Observed by the DEMETER Spacecraft and the Kannuslehto Station: Spatial Extent and Propagation to the Ground","authors":"K. Drastichová,&nbsp;F. Němec,&nbsp;J. Manninen","doi":"10.1029/2024JA032802","DOIUrl":"https://doi.org/10.1029/2024JA032802","url":null,"abstract":"<p>We use conjugate observations of magnetospheric whistler-mode waves at frequencies up to 16 kHz by the DEMETER spacecraft (at an altitude of approximately 660 km) and the ground-based Kannuslehto station in Finland <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 <mo>≈</mo>\u0000 <mn>5.38</mn>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $(Lapprox 5.38)$</annotation>\u0000 </semantics></math> to investigate the wave propagation to the ground and their characteristic spatial scales. For this purpose, we evaluate correlations between the wave intensities measured by the spacecraft and the ground-based station at various frequencies as a function of their longitudinal and L-shell separations. Two different approaches are used: (a) direct correlation of wave intensities measured at the same times and (b) correlation of wave intensities within corresponding frequency-time windows, focusing on the identification of the same frequency-time wave signatures. We show that the characteristic longitudinal scales of the investigated waves are between about <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>60</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $60{}^{circ}$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>90</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $90{}^{circ}$</annotation>\u0000 </semantics></math>. We further demonstrate that, while the wave intensities measured by DEMETER are generally larger during periods of enhanced geomagnetic activity, wave intensities measured on the ground during increased activity are only slightly larger during the daytime and decrease during the nighttime.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA032802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precipitation of Auroral Electrons Accelerated at Very High Altitudes: Impact on the Ionosphere and a Possible Acceleration Mechanism","authors":"S. Imajo,&nbsp;Y. Miyoshi,&nbsp;Y. Kazama,&nbsp;K. Asamura,&nbsp;I. Shinohara,&nbsp;K. Shiokawa,&nbsp;Y. Kasahara,&nbsp;Y. Kasaba,&nbsp;A. Matsuoka,&nbsp;S.-Y. Wang,&nbsp;S. W. Y. Tam,&nbsp;T.-F. Chang,&nbsp;B.-J. Wang,&nbsp;C.-W. Jun,&nbsp;M. Teramoto,&nbsp;S. Kurita,&nbsp;F. Tsuchiya,&nbsp;A. Kumamoto,&nbsp;K. Saito,&nbsp;T. Hori","doi":"10.1029/2024JA032696","DOIUrl":"https://doi.org/10.1029/2024JA032696","url":null,"abstract":"<p>The Arase satellite observed the precipitation of monoenergetic electrons accelerated from a very high altitude above 32,000 km altitude on 16 September 2017. The event was selected in the period when the high-angular resolution channel of the electron detector looked at pitch angles within ∼5° from the ambient magnetic field direction, and thereby was the first to examine the detailed distribution of electron flux near the energy-dependent loss cone at such high altitudes. The potential energy below the satellite estimated from the observed energy-dependence of the loss cone was consistent with the energy of the upgoing ion beams, indicating that ionospheric ions were accelerated by a lower-altitude acceleration region. The accelerated electrons inside the loss cone carried a significant net field-aligned current (FAC) density corresponding to ionospheric-altitude FAC of up to ∼3μA/m². Based on the anisotropy of the accelerated electrons, we estimated the height of the upper boundary of the acceleration region to be &gt;∼2 <i>R</i>_<i>E</i> above the satellite. The height distribution of the acceleration region below the satellite, estimated from the frequency of auroral kilometric radiation, was ∼4,000–13,000 km altitude, suggesting that the very-high-altitude acceleration region was separated from the lower acceleration region. Additionally, we observed time domain structure (TDS) electric fields on a subsecond time scale with a thin FAC indicated by magnetic deflections. Such a TDS may be generated by the formation of double layers in the magnetotail, and its potential drop could significantly contribute (∼40%–60%) to the parallel energization of precipitating auroral electrons.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142231065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Radiation Belt Dynamics Using a Positivity-Preserving Finite Volume Method on General Meshes","authors":"Peng Peng,&nbsp;Xin Tao,&nbsp;Zong Peng,&nbsp;Yan Jiang,&nbsp;Zhiming Gao,&nbsp;Di Yang,&nbsp;Jay M. Albert,&nbsp;Anthony A. Chan","doi":"10.1029/2024JA032919","DOIUrl":"https://doi.org/10.1029/2024JA032919","url":null,"abstract":"<p>Standard finite volume or finite difference methods may produce unphysical negative solutions of phase space density when applied to radiation belt diffusion equation with cross diffusion terms. In this work, we apply a recently proposed positivity-preserving finite volume (PPFV) method to a 2D diffusion problem of radiation belt electrons with both structured and unstructured meshes. Our test using a model problem shows that the new method does not produce unphysical negative solutions with both types of meshes even with strong cross-diffusion terms. By applying the method to the 2D pitch angle and energy diffusion problem, we demonstrate that the method achieves positivity of solutions without requiring excessive number of grid points and shows good agreement with previous results obtained using a layer method. The ability of preserving positivity of the solution with unstructured meshes allows the method to handle complex boundary configurations. Our results suggest that the new PPFV method could be useful in modeling radiation belt diffusion processes or in building a physics-based forecast model.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142174224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Maps of Plasmaspheric Erosion and Refilling for Varying Geomagnetic Conditions","authors":"Tyler B. Bishop,&nbsp;Lauren W. Blum","doi":"10.1029/2024JA032587","DOIUrl":"https://doi.org/10.1029/2024JA032587","url":null,"abstract":"<p>The plasmasphere accounts for the majority of the mass of Earth's magnetosphere and contains most of the cold ion (1 eV) population. The plasmasphere is extremely dynamic, undergoing a constant cycle of erosion and refilling. In this paper we perform a statistical study of erosion and refilling rates using 6 years of data from the Van Allen Probes from the beginning of 2013 through the end of 2018. Using in-situ density measurements derived from the upper hybrid resonance line, we create global maps of the erosion and refilling rates over a wide range of L shells and local times. Sorting the data by L shell, magnetic local time, and distance to the plasmapause, we characterize the absolute and relative rates of erosion and refilling during a variety of geomagnetic conditions. We also examine three case studies of geomagnetic storms and compare their density evolutions during the recovery period. Our results are in agreement with refilling rates found by previous statistical studies using different methods, but somewhat lower than many of the case studies reported. We find median erosion rates of 164, 83, and 43 cm⁻³/day and refilling rates of 87, 42, and 27 cm⁻³/day at L = 3, 4 and 5, respectively when Kp <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≤</mo>\u0000 </mrow>\u0000 <annotation> ${le} $</annotation>\u0000 </semantics></math> 3. We also find little local time dependence for both erosion and refilling rates.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA032587","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Compression of the Plasma Sheet and Magnetotail During Intense Storms From THEMIS Observations","authors":"S. W. Alqeeq,&nbsp;D. Fontaine,&nbsp;O. Le Contel,&nbsp;M. Akhavan Tafti,&nbsp;E. Cazzola,&nbsp;T. Atilaw,&nbsp;V. Angelopoulos,&nbsp;H. U. Auster","doi":"10.1029/2024JA032888","DOIUrl":"https://doi.org/10.1029/2024JA032888","url":null,"abstract":"<p>We estimate the global impact of storms on the global structure and dynamics of the night side plasma sheet from observations by the NASA mission Time History of Events and Macroscale Interactions during Substorms (THEMIS). We focus on an intense storm occurring in December 2015 triggered by interplanetary coronal mass ejections (ICMEs). It starts with a storm sudden commencement (SSC) phase (SYM-H <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math> +50 nT) followed by a growth phase (SYM-H <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math> −188 nT at the minimum) and then a long recovery phase lasting several days. We investigate THEMIS observations when the spacecraft were located in the midnight sector of the plasma sheet at distances typically between 8 and 13 Earth's radii. It is found that the plasma sheet has been globally compressed up to a value of about <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mo>&gt;</mo>\u0000 </mrow>\u0000 <annotation> ${sim} &gt; $</annotation>\u0000 </semantics></math>4 nPa during the SSC and main phases, that is, 8 times larger than its value during the quiet phase before the event. This compression occurs during periods of high dynamic pressure in the ICME (20 nPa) about one order of magnitude larger than its value in the pristine solar wind. We infer a global increase of the lobe magnetic field from 30 to 100 nT, confirmed by THEMIS data just outside the plasma sheet. During the SSC and main phases, the plasma sheet is found thinner by a factor of 2 relative to its thickness at quiet times, while the Tsyganenko T96 magnetic field model shows very stretched magnetic field lines from inner magnetospheric regions toward the night side. During the recovery phase, whereas the interplanetary pressure has dropped off, the plasma sheet tends to gradually recover its quiet phase characteristics (pressure, thickness, magnetic configuration, etc.) during a long recovery phase of several days.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Merging Mesoscale Magnetotail Features and Ground B-Field Perturbation Network Connectivity During Substorm Activity","authors":"M. Adewuyi,&nbsp;A. Keesee,&nbsp;B. Ferdousi","doi":"10.1029/2024JA032598","DOIUrl":"https://doi.org/10.1029/2024JA032598","url":null,"abstract":"<p>The connection between the magnetosphere and ionosphere is particularly dynamic during substorms. Mesoscale features in the magnetotail are consistent with substorm activity, including magnetic reconnection in the tail, flow channels, and particle injections. Observations of substorm related phenomena can be made using energetic neutral atom (ENA) imagers, in situ satellite measurements, and ground based magnetic field perturbation measurements. Analysis of the 10 October 2014 isolated substorm event is presented. Comparison of the spatial and temporal dynamics of the features seen in equatorial maps generated from ENA data are made with inner magnetosphere in situ measurements and ionospheric features with network analysis of the SuperMAG data. An MHD simulation of the event using OpenGGCM is also compared with the data.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142158566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Auroral Bead Propagation: Explanation Based on the Conservation of Vorticity","authors":"Shinichi Ohtani,&nbsp;Tetsuo Motoba","doi":"10.1029/2024JA032904","DOIUrl":"https://doi.org/10.1029/2024JA032904","url":null,"abstract":"<p>The beading of auroral arcs often takes place at substorm onset. It is known that auroral beads propagate more often eastward than westward at several km/s, which is difficult to explain by existing models. We investigate this issue observationally and theoretically. First, based on previous research and additional statistical analysis, we suggest that (a) auroral beads often propagate eastward in the presence of westward background convection, and (b) background ionospheric convection may be better represented by large-scale convection for westward propagation, and by meso-scale convection for eastward propagation. Then we model auroral beads as vortices of ionospheric flow, and consider the longitudinal propagation of their meridional displacement based on the conservation of vorticity. Here it is crucial that the background zonal flow has vorticity (i.e., flow shear) changing with latitude. It is found that the wave propagates either parallel or anti-parallel to the background flow depending on whether the background vorticity increases or decreases in latitude, and if its latitudinal scale is significantly smaller than the longitudinal wavelength, the phase velocity exceeds the background flow speed. The result suggests that the latitudinal structure of the background flow is crucial for the bead propagation. More specifically, the aforementioned feature (a) implies that the zonal flow associated with eastward propagation is confined in latitude, which may correspond to the preonset approach of mesoscale flows. In contrast, the large-scale ionospheric flow suggested for westward propagation as described in (b) may correspond to the global convection of the conventional growth phase.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA032904","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142158665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local Empirical Modeling of NmF2 Using Ionosonde Observations and the FISM2 Solar EUV Model","authors":"D. Singh,&nbsp;L. P. Goncharenko,&nbsp;I. A. Galkin,&nbsp;P. C. Chamberlin,&nbsp;F. Redondo","doi":"10.1029/2024JA032697","DOIUrl":"https://doi.org/10.1029/2024JA032697","url":null,"abstract":"<p>Local empirical models of the F2 layer peak electron density (NmF2) are developed for 43 low- middle latitude ionosonde stations using auto-scaled data from Lowell GIRO data center and manually scaled data from World Data Center for Ionosphere and Space Weather. Data coverage at these stations ranges from a few years to up to 6 decades. Flare Irradiance Spectral Model index version 2 (FISM2) and ap3 index are used to parametrize the solar extreme ultraviolet (EUV) flux and geomagnetic activity dependence of NmF2. Learning curves suggest that approximately 8 years of data coverage is required to constrain the solar activity dependence of NmF2. Output of local models altogether captures well known anomalies of the F2 ionospheric layer. Performance metrics demonstrate that the model parametrized using FISM2 has better accuracy than a similarly parametrized model with F10.7, as well as than the IRI-2020 model. Skill score metrics indicate that the FISM2 based model outperforms F10.7 model at all solar activity levels. The improved accuracy of model with FISM2 over F10.7 is due to better representation of solar rotation by FISM2, and due to its performance at solar extremum. Application of singular spectrum analysis to model output reveals that solar rotation contributes to about 2%–3% of the variance in NmF2 data and FISM2 based model, while F10.7 based models overestimate the strength of solar rotation to be at 4%–7%. At solar extremum, both F10.7-based model and IRI-2020 tend to overestimate the NmF2 while FISM2 provides the most accurate prediction out of three.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA032697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}