Northeast Radio Observatory Corporation

<strong class="journal-contentHeaderColor">Abstract.</strong> We present dynamic mid-latitude ionospheric changes associated with the Apr 8, 2024 solar eclipse, as observed in the eastern to central United States using wide-field scans from the Millstone Hill incoherent scatter radar. The radar&rsquo;s field of view covers a large portion of the continental US (25&ndash;55&deg; N, 75&ndash;95&deg; W), and is capable of observing altitude profiles from the E-region up to the topside ionosphere. We find that extensive ionospheric changes triggered by the eclipse along the US east coast were detected before the totality shadow entered the continent, and in particular when the eclipse obscuration percentage became greater than 0 %. During the time interval where the obscuration percentage is significant (&gt;75 %) over the radar scanning region, we find maximum electron density (<em>N_e</em>) drops of up to 50 % (2 &times;10¹¹ m^&minus;3) in the F1 region (200&ndash;250 km) to the north of the totality path, with a large <em>N_e</em> decrease lasting for 1 hour, from 19&ndash;20 UT. In the topside ionosphere, a delayed drop in <em>N_e</em> values occurred beginning 30 min&ndash;1 hour later, with electron density decreasing by 40&ndash;50 % (2.5&ndash;3 &times;10¹¹ m^&minus;3) below background levels, followed by a recovery to typical background values only after 22 UT. The electron temperature (<em>T_e</em>) showed a faster response and recovery rate which closely mirrored the eclipse obscuration level, with a visible decrease in <em>T_e</em> when the obscuration rate exceeded 0&ndash;30 % depending on altitude, with a faster response time at higher altitudes. A decrease in <em>T_e</em> of the order of 40 % (850 K) was observed at altitudes from 325&ndash;400 km between 18.75&ndash;19.25 UT. The ion temperature (<em>T_i</em>), similar to <em>T_e</em>, responded rapidly to the obscuration level as it exceeded 30 %, with up to 20 % or 225 K reduction in a narrow geographic area and at two distinct altitude regions: 200&ndash;225 km and 300&ndash;325 km between 19&ndash;20 UT.

<strong class="journal-contentHeaderColor">Abstract.</strong> We present dynamic mid-latitude ionospheric changes associated with the Apr 8, 2024 solar eclipse, as observed in the eastern to central United States using wide-field scans from the Millstone Hill incoherent scatter radar. The radar&rsquo;s field of view covers a large portion of the continental US (25&ndash;55&deg; N, 75&ndash;95&deg; W), and is capable of observing altitude profiles from the E-region up to the topside ionosphere. We find that extensive ionospheric changes triggered by the eclipse along the US east coast were detected before the totality shadow entered the continent, and in particular when the eclipse obscuration percentage became greater than 0 %. During the time interval where the obscuration percentage is significant (&gt;75 %) over the radar scanning region, we find maximum electron density (<em>N_e</em>) drops of up to 50 % (2 &times;10¹¹ m^&minus;3) in the F1 region (200&ndash;250 km) to the north of the totality path, with a large <em>N_e</em> decrease lasting for 1 hour, from 19&ndash;20 UT. In the topside ionosphere, a delayed drop in <em>N_e</em> values occurred beginning 30 min&ndash;1 hour later, with electron density decreasing by 40&ndash;50 % (2.5&ndash;3 &times;10¹¹ m^&minus;3) below background levels, followed by a recovery to typical background values only after 22 UT. The electron temperature (<em>T_e</em>) showed a faster response and recovery rate which closely mirrored the eclipse obscuration level, with a visible decrease in <em>T_e</em> when the obscuration rate exceeded 0&ndash;30 % depending on altitude, with a faster response time at higher altitudes. A decrease in <em>T_e</em> of the order of 40 % (850 K) was observed at altitudes from 325&ndash;400 km between 18.75&ndash;19.25 UT. The ion temperature (<em>T_i</em>), similar to <em>T_e</em>, responded rapidly to the obscuration level as it exceeded 30 %, with up to 20 % or 225 K reduction in a narrow geographic area and at two distinct altitude regions: 200&ndash;225 km and 300&ndash;325 km between 19&ndash;20 UT.

Abstract The Ross Ice Shelf (RIS) in West Antarctica experienced extensive surface melting in January 2016, driven by warm humid air transported from over the Southern Ocean. Few studies have reported increased atmospheric water vapor and turbulent mixing during this event in this region, where the availability of surface measurements is challenging due to its remoteness and extreme conditions. Here, we used atmospheric estimates from a network of 13 GNSS receivers deployed on the RIS during the austral summer of 2015–2016. We estimated a spatiotemporally varying structure function across the network to quantify the relative strength of atmospheric turbulence, which exceeded values during non‐melting periods in the RIS by a factor of about 4. This result further supports the atmospheric connection of the ice‐shelf melting event. The result also demonstrates a new application of GNSS not previously studied, namely, ice‐shelf melting through turbulence sensitivity in the polar troposphere.

IntroductionIn Italy, elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) in combination with ivacaftor was reimbursed starting July 2021 for use in people with cystic fibrosis (CF) aged ≥ 12 years homozygous for F508del mutation or heterozygous with at least one F508del allele and with a minimal function mutation. This study assessed the impact of ELX/TEZ/IVA on real-world outcomes among this population in Italy.MethodsThis observational study used data from Verona CF Center from October 2018 to December 2022 to describe the impact of ELX/TEZ/IVA on individuals aged ≥ 12 years with ≥ 1 F508del allele on lung function and healthcare resource utilization (HCRU). Lung function (percent predicted forced expiratory volume in 1 s [ppFEV1]), hospitalizations, outpatient visits, pulmonary exacerbations (PEx), and prescribed medications were analyzed during baseline and follow-up periods (12 months pre- and post-ELX/TEZ/IVA initiation, respectively) and reported as change from baseline.ResultsA total of 149 individuals were included (mean [standard deviation, SD] age: 32.6 [12.25] years). A mean improvement in ppFEV1 of +14.38 percentage points (95% confidence interval [CI] 12.65; 16.10) was observed during the follow-up period. An 87.2% reduction in the annualized PEx rate (rate ratio: 0.128 [95% CI 0.085; 0.187]) and an 85.4% reduction in the annualized hospitalization rate (rate ratio: 0.146 [95% CI 0.096; 0.213]) were observed during follow-up compared to baseline. Reductions in the proportion of individuals requiring prescription medications, including intravenous antibiotics, mucolytic agents, and bronchodilators, were observed.ConclusionSubstantial improvements in lung function and reductions in HCRU were observed after treatment with ELX/TEZ/IVA in the Verona CF Center. Results contribute to the growing evidence of country-specific real-world data on the positive impact of ELX/TEZ/IVA.Supplementary InformationThe online version contains supplementary material available at 10.1007/s41030-025-00334-x.

Abstract This study investigates the four‐peak electron density structure in the Equatorial Ionization Anomaly (EIA) during the intense geomagnetic storms of 10–20 May 2024, utilizing dayside data at ∼500 km from the China Seismo‐Electromagnetic Satellite (CSES‐01). Observations revealed distinct four peaks in latitudinal profiles of electron density, symmetrically distributed across both hemispheres. Particularly, the poleward crests can expand beyond ±30° quasi‐dipole latitude during the 10 May superstorm. To reveal the potential driver of such unique EIA structure, statistical analysis is conducted on 35 CSES‐01 orbits which identified the four‐peak phenomenon. The enhanced equatorial electrojet activity, inferred from the scalar magnetic field residuals, indicates that the four‐peak morphology is likely related to the prompt penetration electric field (PPEF). Superposed epoch analysis also highlighted that intensification of the mean SuperMAG |SML| index preceded the onset of four‐peak structures by ∼20 min, whereas the mean eastward equatorial electric field, derived from an empirical model of the interplanetary electric field driven penetration, exhibits no statistically significant enhancement, implying that substorm‐associated PPEF may be the primary driver of this type of EIA structure. This study advances understanding of EIA variability under extreme space weather conditions and the findings underscore the critical role of magnetosphere‐ionosphere coupling via substorm‐driven electric fields in reshaping storm‐time ionospheric plasma distribution.

Abstract. We present dynamic mid-latitude ionospheric changes associated with the Apr 8, 2024 solar eclipse, as observed in the eastern to central United States using wide-field scans from the Millstone Hill incoherent scatter radar. The radar’s field of view covers a large portion of the continental US (25–55° N, 75–95° W), and is capable of observing altitude profiles from the E-region up to the topside ionosphere. We find that extensive ionospheric changes triggered by the eclipse along the US east coast were detected before the totality shadow entered the continent, and in particular when the eclipse obscuration percentage became greater than 0 %. During the time interval where the obscuration percentage is significant (&gt;75 %) over the radar scanning region, we find maximum electron density (Ne) drops of up to 50 % (2 ×1011 m−3) in the F1 region (200–250 km) to the north of the totality path, with a large Ne decrease lasting for 1 hour, from 19–20 UT. In the topside ionosphere, a delayed drop in Ne values occurred beginning 30 min–1 hour later, with electron density decreasing by 40–50 % (2.5–3 ×1011 m−3) below background levels, followed by a recovery to typical background values only after 22 UT. The electron temperature (Te) showed a faster response and recovery rate which closely mirrored the eclipse obscuration level, with a visible decrease in Te when the obscuration rate exceeded 0–30 % depending on altitude, with a faster response time at higher altitudes. A decrease in Te of the order of 40 % (850 K) was observed at altitudes from 325–400 km between 18.75–19.25 UT. The ion temperature (Ti), similar to Te, responded rapidly to the obscuration level as it exceeded 30 %, with up to 20 % or 225 K reduction in a narrow geographic area and at two distinct altitude regions: 200–225 km and 300–325 km between 19–20 UT.

Abstract We expand the assessment study of modeling capabilities in the prediction of foF2 and hmF2 for the ionospheric climatology (Tsagouri et al., 2018, https://doi.org/10.1029/2018sw002035) by using updated empirical (IRI and MIT Empirical model) and physics‐based models (CTIPe, WACCM‐X, and TIE‐GCM) as well as the additional observations in the southern hemisphere. Monthly medians of foF2 and hmF2 are considered to evaluate the model performance for the entire year of 2012. For quantitative evaluation, we employ several metrics including the correlation coefficient (R), coefficient of determination (R2), root‐mean square error (RMSE), mean error (ME), and mean relative error (MRE). The linear regression analysis shows that the empirical models perform much better than physics‐based models for foF2 but to a lesser degree for hmF2. There are negligible hemispheric differences in the predictions from empirical models. All the physics‐based models show relatively good correlations with the observations for foF2 in the northern hemisphere compared to the southern hemisphere, but the hemispheric differences are small for hmF2. The results of the study indicate that recent versions of empirical models tend to perform better than old versions of the models, but this is not always true for physics‐based models.

Abstract Prior observational uncertainties have hindered the clear understanding of the link between tropospheric Lamb waves and ionospheric disturbances. In this study, we precisely extracted ionospheric Lamb waves originating from the epicenter of the 15 January 2022 Tonga eruption, propagating upward in a conical structure. This was achieved by using line‐of‐sight observations from the BeiDou geostationary satellites, which eliminated the spatiotemporal ambiguity introduced by the relative motion of Global Positioning System satellites, enabling the clear extraction of the Lamb signal in the ionosphere. The observed L0 mode speed (∼323 m/s) and period (∼30 min) were consistent with those of the tropospheric Lamb wave. It suggested that the ionospheric Lamb wave is likely driven by the surface Lamb wave, leading to a conical wave‐front that extends in altitude. This study highlights the significant role of Lamb waves in transmitting energy from epicenters through Earth's atmosphere and plasma systems.