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Thermospheric Wind Response to March 2023 Storm: Largest Wind Ever Observed With a Fabry-Perot Interferometer in Tromsø, Norway Since 2009 2023 年 3 月风暴的热层风响应：自 2009 年以来在挪威特罗姆瑟使用法布里-珀罗干涉仪观测到的最大风力

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-27 DOI: 10.1029/2023sw003728

S. Oyama, H. Vanhamäki, L. Cai, A. Shinbori, K. Hosokawa, T. Sakanoi, K. Shiokawa, A. Aikio, I. I. Virtanen, Y. Ogawa, Y. Miyoshi, S. Kurita, N. Nishitani

{"title":"Thermospheric Wind Response to March 2023 Storm: Largest Wind Ever Observed With a Fabry-Perot Interferometer in Tromsø, Norway Since 2009","authors":"S. Oyama, H. Vanhamäki, L. Cai, A. Shinbori, K. Hosokawa, T. Sakanoi, K. Shiokawa, A. Aikio, I. I. Virtanen, Y. Ogawa, Y. Miyoshi, S. Kurita, N. Nishitani","doi":"10.1029/2023sw003728","DOIUrl":"https://doi.org/10.1029/2023sw003728","url":null,"abstract":"Solar cycles 24–25 were quiet until a geomagnetic storm with a Sym-H index of −170 nT occurred in late March 2023. On March 23–24, a Fabry-Perot interferometer (FPI; 630 nm) in Tromsø, Norway, recorded the highest thermospheric wind speed of over 500 m/s since 2009. Comparisons with magnetometer readings in Scandinavia showed that a large amount of electromagnetic energy was transferred to the ionosphere-thermosphere system. Total electron content maps suggested an enlarged auroral oval and revealed that the FPI observed winds near the polar cap instead of inside the oval for a long period during the storm main phase. The FPI wind had a strong equatorward component during the storm, likely because of the powerful anti-sunward ionospheric plasma flow in the polar cap. The positive Y-component of the IMF for 6 days before the storm caused a successive westward component of the FPI-measured wind during the storm main phase. On March 24, the first day of the storm recovery phase, thermospheric wind disturbed and the ionospheric density decreased significantly at high latitudes. This density depression lasted for several days, and a large amount of electromagnetic energy during the storm modified the thermospheric dynamics and ionospheric plasma density.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"45 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140003557","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}

引用次数: 0

Observations of Geomagnetic Crochet at High-Latitudes Due To X1.5 Class Solar Flare on 3 July 2021 2021 年 7 月 3 日 X1.5 级太阳耀斑引起的高纬度地磁钩编观测数据

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-23 DOI: 10.1029/2023sw003719

S. S. Rao, Nandita Srivastava, Monti Chakraborty, Sandeep Kumar, D. Chakrabarty

{"title":"Observations of Geomagnetic Crochet at High-Latitudes Due To X1.5 Class Solar Flare on 3 July 2021","authors":"S. S. Rao, Nandita Srivastava, Monti Chakraborty, Sandeep Kumar, D. Chakrabarty","doi":"10.1029/2023sw003719","DOIUrl":"https://doi.org/10.1029/2023sw003719","url":null,"abstract":"On 3 July 2021, an X1.5 solar flare from the National Oceanic and Atmospheric Administration solar Active Region AR12838 (24°N, 88°W) occurred at 14:18 UT, peaked at 14:29 UT, and decayed at 14:34 UT. The study of this X1.5 solar flare is significant due to its unique geomagnetic crochet feature at high latitudes and its effective signature on Earth. The study examined X-rays, the extreme ultraviolet spectrum, ionospheric equivalent current (IEC), and geomagnetic field components. The study reveals a sudden increase in IEC during the X1.5 flare episode, forming a zonal current region and producing a geomagnetic crochet signature in geomagnetic field components at high latitudes (50°–80°N) along the 11°–26°E longitude sector during the flare peak time. All three geomagnetic field components show different sensitivity to the solar flare effect (sfe), and the amplitude and phase of the geomagnetic crochet across latitudes (for a given longitude) are consistent with the variations in the IEC. The present study is the first to appraise geomagnetic crochets of low magnitude (8–40 nT) and short duration (10–15 min) at high latitudes, particularly in the polar cusp region, during the X-class limb flare.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"2015 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139967961","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}

引用次数: 0

Validating a UK Geomagnetically Induced Current Model Using Differential Magnetometer Measurements 利用差分磁强计测量验证英国地磁诱导电流模型

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-23 DOI: 10.1029/2023sw003769

J. Hübert, C. D. Beggan, G. S. Richardson, N. Gomez-Perez, A. Collins, A. W. P. Thomson

{"title":"Validating a UK Geomagnetically Induced Current Model Using Differential Magnetometer Measurements","authors":"J. Hübert, C. D. Beggan, G. S. Richardson, N. Gomez-Perez, A. Collins, A. W. P. Thomson","doi":"10.1029/2023sw003769","DOIUrl":"https://doi.org/10.1029/2023sw003769","url":null,"abstract":"Extreme space weather can damage ground-based infrastructure such as power lines, railways and gas pipelines through geomagnetically induced currents (GICs). Modeling GICs requires knowledge about the source magnetic field and the electrical conductivity structure of the Earth to calculate ground electric fields during enhanced geomagnetic activity. The electric field, in combination with detailed information about the power grid topology, enable the modeling of GICs in high-voltage (HV) power lines. Directly monitoring GICs in substations is possible with a Hall probe, but scarcely realized in the UK. Therefore we deployed the differential magnetometer method (DMM) to measure GICs at 12 sites in the UK power grid. The DMM includes the installation of two fluxgate magnetometers, one directly under a power line affected by GICs, and one as a remote site. The difference in recordings of the magnetic field at each instrument yields an estimate of the GICs in the respective power line segment via the Biot-Savart law. We collected data across the UK in 2018–2022, monitoring HV line segments where previous research indicated high GIC risk. We recorded magnetometer data during several smaller storms that allow detailed analysis of our GIC model. For the ground electric field computations we used recent magnetotelluric (MT) measurements recorded close to the DMM sites. Our results show that there is strong agreement in both amplitude and signal shape between measured and modeled line and substation GICs when using our HV model and the realistic electric field estimates derived from MT data.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"176 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139946966","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}

引用次数: 0

Unsupervised Anomaly Detection With Variational Autoencoders Applied to Full-Disk Solar Images 将变异自动编码器应用于全磁盘太阳图像的无监督异常检测

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-22 DOI: 10.1029/2023sw003516

Marius Giger, André Csillaghy

{"title":"Unsupervised Anomaly Detection With Variational Autoencoders Applied to Full-Disk Solar Images","authors":"Marius Giger, André Csillaghy","doi":"10.1029/2023sw003516","DOIUrl":"https://doi.org/10.1029/2023sw003516","url":null,"abstract":"Deep learning is successful in many fields due to its ability to learn strong feature representations without the need for hand-crafted features, resulting in models with high representational power. However, many of these models are based on supervised learning and therefore depend on the availability of large annotated data sets. These are often difficult to obtain because they require human input. A common challenge for researchers in space weather is the sparsity of annotations in many of the available data sets, which are either unlabeled or have ambiguous labels. To alleviate the data bottleneck of loosely annotated data sets, unsupervised deep learning has become an important strategy, with anomaly detection being one of the most prominent applications. Unsupervised models have been successfully applied in various domains, such as medical imaging or video surveillance, to distinguish normal from abnormal data. In this work, we investigate how a purely unsupervised approach can be used to detect and extract solar phenomena in extreme ultraviolet images from the NASA SDO spacecraft. We show how a model based on variational autoencoders can be used to detect out-of-distribution samples and to localize regions of interest for solar activity. By using an unsupervised approach, we hope to contribute to space weather monitoring tools and further improve the understanding of space weather drivers.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"21 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139946845","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}

引用次数: 0

Climatology of Dayside E-Region Zonal Neutral Wind Shears From ICON-MIGHTI Observations 根据 ICON-MIGHTI 观测数据绘制的东区日侧地带性中性风切变气候图

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-21 DOI: 10.1029/2023sw003670

Minjing Li, Yue Deng, Brian J. Harding, Scott England

{"title":"Climatology of Dayside E-Region Zonal Neutral Wind Shears From ICON-MIGHTI Observations","authors":"Minjing Li, Yue Deng, Brian J. Harding, Scott England","doi":"10.1029/2023sw003670","DOIUrl":"https://doi.org/10.1029/2023sw003670","url":null,"abstract":"Large vertical shears in the E-region neutral zonal winds can lead to ion convergences and contribute to plasma irregularities, but climatological studies of vertical shears of horizontal winds in a global scale are lacking due to the limitations of data coverage. The Ionospheric Connection Explorer (ICON) Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) has provided neutral wind observations with an unprecedented spatial coverage. In this study, the climatology of dayside E-region neutral wind shears has been examined using 2-years’ data (2020–2021). Specifically, the study focuses on large wind shears with a magnitude larger than 20 m/s/km, since large wind shears are more likely to cause significant perturbation in the ionosphere-thermosphere (I-T) system. The results show that the probability of occurrence of large shears is strongly dependent on the altitude, with the vertical profile varying with shear direction, latitude, season, and local time. In general, below 110 km altitude, large negative shears of the eastward wind are most likely to happen during summer at 8–10 LT in 25°N–40°N latitudes, showing a high probability across nearly all longitudes. Meanwhile, large positive shears tend to occur in 10°S–10°N latitudes, with peak probabilities exhibiting roughly consistent longitudinal structures across 8–10 LT in all seasons. The discrepancies between positive and negative large shear distributions underlie different global tidal influences. The large-shear occurrence probabilities above 110 km are generally small, except in latitudes above 25°N during the winter for positive shears.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"23 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925617","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}

引用次数: 0

Using Solar Orbiter as an Upstream Solar Wind Monitor for Real Time Space Weather Predictions 利用太阳轨道器作为上游太阳风监测器进行实时空间天气预测

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-20 DOI: 10.1029/2023sw003628

R. Laker, T. S. Horbury, H. O’Brien, E. J. Fauchon-Jones, V. Angelini, N. Fargette, T. Amerstorfer, M. Bauer, C. Möstl, E. E. Davies, J. A. Davies, R. Harrison, D. Barnes, M. Dumbović

{"title":"Using Solar Orbiter as an Upstream Solar Wind Monitor for Real Time Space Weather Predictions","authors":"R. Laker, T. S. Horbury, H. O’Brien, E. J. Fauchon-Jones, V. Angelini, N. Fargette, T. Amerstorfer, M. Bauer, C. Möstl, E. E. Davies, J. A. Davies, R. Harrison, D. Barnes, M. Dumbović","doi":"10.1029/2023sw003628","DOIUrl":"https://doi.org/10.1029/2023sw003628","url":null,"abstract":"Coronal mass ejections (CMEs) can create significant disruption to human activities and systems on Earth, much of which can be mitigated with prior warning of the upstream solar wind conditions. However, it is currently extremely challenging to accurately predict the arrival time and internal structure of a CME from coronagraph images alone. In this study, we take advantage of a rare opportunity to use Solar Orbiter, at 0.5 au upstream of Earth, as an upstream solar wind monitor. In combination with low-latency images from STEREO-A, we successfully predicted the arrival time of two CME events before they reached Earth. Measurements at Solar Orbiter were used to constrain an ensemble of simulation runs from the ELEvoHI model, reducing the uncertainty in arrival time from 10.4 to 2.5 hr in the first case study. There was also an excellent agreement in the Bz profile between Solar Orbiter and Wind spacecraft for the second case study, despite being separated by 0.5 au and 10° longitude. The opportunity to use Solar Orbiter as an upstream solar wind monitor will repeat once a year, which should further help assess the efficacy upstream in-situ measurements in real time space weather forecasting.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"62 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925691","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}

引用次数: 0

The Impact of Non-Equilibrium Plasma Distributions on Solar Wind Measurements by Vigil's Plasma Analyser 非平衡等离子体分布对 Vigil 等离子体分析仪太阳风测量的影响

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-20 DOI: 10.1029/2023sw003671

H. Zhang, D. Verscharen, G. Nicolaou

{"title":"The Impact of Non-Equilibrium Plasma Distributions on Solar Wind Measurements by Vigil's Plasma Analyser","authors":"H. Zhang, D. Verscharen, G. Nicolaou","doi":"10.1029/2023sw003671","DOIUrl":"https://doi.org/10.1029/2023sw003671","url":null,"abstract":"In order to protect society from space weather impacts, we must monitor space weather and obtain early warnings for extreme events if possible. For this purpose, the European Space Agency is currently preparing to launch the Vigil mission toward the end of this decade as a space-weather monitor at the fifth Lagrange point of the Sun–Earth system. Vigil will carry, amongst other instruments, the Plasma Analyser (PLA) to provide quasi-continuous measurements of solar wind ions. We model the performance of the PLA instrument, considering typical solar wind plasma conditions, to compare the expected observations of PLA with the assumed input conditions of the solar wind. We evaluate the instrument performance under realistic, non-equilibrium plasma conditions, accounting for temperature anisotropies, proton beams, and the contributions from α-particles. We examine the accuracy of the instrument's performance over a range of input solar wind moments. We identify sources of potential errors due to non-equilibrium plasma conditions and link these to instrument characteristics such as its angular and energy resolution and its field of view. We demonstrate the limitations of the instrument and potential improvements such as applying ground-based fitting techniques to obtain more accurate measurements of the solar wind even under non-equilibrium plasma conditions. The use of ground processing of plasma moments instead of on-board processing is crucial for the extraction of reliable measurements.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"16 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925685","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}

引用次数: 0

Correcting Projection Effects in CMEs Using GCS-Based Large Statistics of Multi-Viewpoint Observations 利用基于 GCS 的多视点观测大统计校正 CME 的投影效应

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-19 DOI: 10.1029/2023sw003805

Harshita Gandhi, Ritesh Patel, Vaibhav Pant, Satabdwa Majumdar, Sanchita Pal, Dipankar Banerjee, Huw Morgan

{"title":"Correcting Projection Effects in CMEs Using GCS-Based Large Statistics of Multi-Viewpoint Observations","authors":"Harshita Gandhi, Ritesh Patel, Vaibhav Pant, Satabdwa Majumdar, Sanchita Pal, Dipankar Banerjee, Huw Morgan","doi":"10.1029/2023sw003805","DOIUrl":"https://doi.org/10.1029/2023sw003805","url":null,"abstract":"This study addresses the limitations of single-viewpoint observations of Coronal Mass Ejections (CMEs) by presenting results from a 3D catalog of 360 CMEs during solar cycle 24, fitted using the Graduated Cylindrical Shell (GCS) model. The data set combines 326 previously analyzed CMEs and 34 newly examined events, categorized by their source regions into active region (AR) eruptions, active prominence (AP) eruptions, and prominence eruptions (PE). Estimates of errors are made using a bootstrapping approach. The findings highlight that the average 3D speed of CMEs is ∼1.3 times greater than the 2D speed. PE CMEs tend to be slow, with an average speed of 432 km s−1. AR and AP speeds are higher, at 723 and 813 km s−1, respectively, with the latter having fewer slow CMEs. The distinctive behavior of AP CMEs is attributed to factors like overlying magnetic field distribution or geometric complexities leading to less accurate GCS fits. A linear fit of projected speed to width gives a gradient of ∼2 km s−1 deg−1, which increases to 5 km s−1 deg−1 when the GCS-fitted ‘true’ parameters are used. Notably, AR CMEs exhibit a high gradient of 7 km s−1 deg−1, while AP CMEs show a gradient of 4 km s−1 deg−1. PE CMEs, however, lack a significant speed-width relationship. We show that fitting multi-viewpoint CME images to a geometrical model such as GCS is important to study the statistical properties of CMEs, and can lead to a deeper insight into CME behavior that is essential for improving future space weather forecasting.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"1 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925608","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}

引用次数: 0

An Improved Stochastic Model for the Geodetic GNSS Receivers Under Ionospheric Scintillation at Low Latitudes 低纬度电离层闪烁条件下大地测量全球导航卫星系统接收器的改进随机模型

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-18 DOI: 10.1029/2023sw003632

Xiaomin Luo, Yingzong Lin, Xiaolei Dai, Shaofeng Bian, Dezhong Chen

{"title":"An Improved Stochastic Model for the Geodetic GNSS Receivers Under Ionospheric Scintillation at Low Latitudes","authors":"Xiaomin Luo, Yingzong Lin, Xiaolei Dai, Shaofeng Bian, Dezhong Chen","doi":"10.1029/2023sw003632","DOIUrl":"https://doi.org/10.1029/2023sw003632","url":null,"abstract":"The receiver tracking error stochastic (RTES) model can improve GNSS precise point positioning (PPP) performance under ionospheric scintillation. However, it relies on scintillation products derived from ionospheric scintillation monitoring receivers (ISMRs), which means the RTES model cannot be used for abundant geodetic GNSS receivers. In this study, we propose an improved RTES, referred to as Impr_RTES model, to mitigate scintillation effects on geodetic GNSS receivers at low latitudes, where severe scintillation frequently occurs. In the Impr_RTES model, the tracking error variances at the output of code delay locked loop are calculated by using the index S4c, and these of phase locked loop are modeled by using the rate of total electron content index (ROTI) and S4c. Both S4c and ROTI can be derived from geodetic GNSS receivers. The performance of the Impr_RTES model is validated by using the data sets from ISMR and geodetic receivers, respectively. Using one month of GPS data collected at HNLW station installed with ISMR in Hainan of China from 1 to 28 February in 2023, statistical results indicate that the PPP solution based on Impr_RTES model can improve the positioning accuracy by approximately 22.6%, 23.8%, and 30.2% in the east, north, and up directions, respectively, over the elevation angle stochastic (EAS) model. Meanwhile, the positioning performance of Impr_RTES PPP is comparable to that of RTES PPP. For the GPS data from geodetic receivers, experimental results suggest that compared with EAS, the Impr_RTES model can obviously mitigate scintillation effects on PPP.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"9 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925611","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}

引用次数: 0

Ionospheric Disturbances Generated by the 2015 Calbuco Eruption: Comparison of GITM-R Simulations and GNSS Observations 2015 年卡尔布科火山爆发产生的电离层扰动：GITM-R 模拟与全球导航卫星系统观测结果的比较

IF 3.7 2区地球科学

Space Weather Pub Date : 2024-02-17 DOI: 10.1029/2023sw003502

J. Tyska, Y. Deng, S. Zhang, C. Y. Lin

{"title":"Ionospheric Disturbances Generated by the 2015 Calbuco Eruption: Comparison of GITM-R Simulations and GNSS Observations","authors":"J. Tyska, Y. Deng, S. Zhang, C. Y. Lin","doi":"10.1029/2023sw003502","DOIUrl":"https://doi.org/10.1029/2023sw003502","url":null,"abstract":"Volcanic eruptions provide broad spectral forcing to the atmosphere and understanding the primary mechanisms that are relevant to explain the variety in waveform characteristics in the Ionosphere-Thermosphere (IT) is still an important open question for the community. In this study, Global Navigation Satellite System (GNSS) Total Electron Content (TEC) data are analyzed and compared to simulations performed by the Global Ionosphere-Thermosphere Model with Local Mesh Refinement (GITM-R) for the first phase of the 2015 Calbuco eruption that occurred on 22 April. A simplified source representation and spectral acoustic-gravity wave (AGW) propagation model are used to specify the perturbation at the lower boundary of GITM-R at 100 km altitude. Two assumptions on the propagation structure, Direct Spherical (DS) and Ground Coupled (GC), are compared to the GNSS data and these modeling specifications show good agreement with different aspects of the observations for some waveform characteristics. Most notably, GITM-R is able to reproduce the relative wave amplitude of AGWs as a function of radial distance from the vent, showing acoustic dominant forcing in the near field (<500 km) and gravity dominant forcing in the far-field (>500 km). The estimated apparent phase speeds from GITM-R simulations are consistent with observations with ∼10% difference from observation for both acoustic wave packets and a trailing gravity mode. The relevance of the simplifications made in the lower atmosphere to the simulated IT response is then discussed.","PeriodicalId":22181,"journal":{"name":"Space Weather","volume":"78 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925687","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}

引用次数: 0