Phase Of Storm Research Articles

Ionospheric behaviors and characteristics in Asian sector during the April 2023 geomagnetic storm with multi-instruments observations

Geomagnetic storms frequently affect satellite navigation, communication and satellite orbits. Monitoring and understanding the ionospheric disturbances and responses to geomagnetic storms are crucial. The detailed ionospheric responses and physical mechanisms to various geomagnetic storms, however, have not yet been extensively studied. In this paper, the ionospheric variation behaviors and features following the April 2023 magnetic storm along the Asian sector are thoroughly studied using multi-instrument observation data, including the Global Navigation Satellite System (GNSS), ionosonde, and other satellites. Large-scale Traveling Ionospheric disturbances (LSTIDs) are observed from BeiDou Geostationary Earth Orbit (GEO) satellites, GPS and GLONASS. LSTIDs traveled with a speed of 760–1300 m/s from high latitude region to low latitude region with a period of about 40 min. The equatorial propagating LSTIDs were generated by coronal mass ejections (CMEs), which occurred in April 2023 with periodic energy input from the auroral area. The poleward LSTIDs are also observed with a velocity of approximately 600–750 m/s and the period is similar. Neutral wind also influenced the characteristics of the ionospheric response. The [O]/[N2] ratio declined during the storm, which led to the formation of the negative storm phases. The largest vertical total electron content (VTEC) is found, and the strengthened region of TEC is mainly centered between ± 20° within geographical latitude. Equatorial Ionospheric Anomaly (EIA) is also observed, which is probably influenced by the electric field. As the time goes on, the peak on the south side of the EIA is disappearing. Meanwhile, the height of the ionospheric maximum electron density rises, and the electron density falls.

Distribution and recovery phase of geomagnetic storms during solar cycles 23 and 24

Abstract Coronal mass ejections (CMEs) and Stream Interaction Regions (SIRs) are the main drivers of intense geomagnetic storms. We study the distribution of geomagnetic storms associated with different drivers during solar cycles 23 and 24 (1996-2019). Although the annual occurrence rate of geomagnetic storms in both cycles tracks the sunspot cycle, the second peak in storm activity lags the second sunspot peak. SIRs contribute significantly to the second peak in storm numbers in both cycles, particularly for moderate to stronger-than-moderate storms. We note semiannual peaks in storm numbers much closer to equinoxes for moderate storms, and slightly shifted from equinoxes for intense and stronger-than-intense storms. We note a significant fraction of multiple-peak storms in both cycles due to isolated ICMEs/SIRs, while single-peak storms from multiple interacting drivers, suggesting a complex relationship between storm steps and their drivers. Our study focuses on investigating the recovery phases of geomagnetic storms and examining their dependencies on various storm parameters. Multiple-peak storms in both cycles have recovery phase duration strongly influenced by slow and fast decay phases with no correlation with the main phase buildup rate and Dst peak. However, the recovery phase in single-peak storms for both cycles depends to some extent on the main phase buildup rate and Dst peak, in addition to slow and fast decay phases. Future research should explore recovery phases of single and multiple-peak storms incorporating in-situ solar wind observations for a deeper understanding of storm evolution and decay processes.

Inter-Correlation Analysis of Magnetic Activity Indices during Varying Geomagnetic Conditions and Phases

The linear interrelationship between the Dst, AE, ap, and the IMF-Bz were presently investigated in pairs and multiples during magnetic quiet (), disturbed (), and combined activities, as well as for different storm phases using data obtained from 1996-2006. The results from the study indicate the highest correlation percentage (%corr) between pairs of indices was for the AE/ap (73%) occurring during the storm onset phase. The %corr was 21-57%, (50-73%), (23-52%), (5-40%), Bz/ap (24-60%), and (7-37%) across various levels of activities. The results for the multiple correlation relationships of the and showed that the magnitudes of the coefficients of best fit are smallest during quiet magnetic activity in comparison to other activities, suggesting that ap and Bz are well explained by the independent variables carrying the coefficient during the quiet condition and can be better inferred during the same period of magnetic activity. The present results suggest that the ap index is well correlated with the Dst as an intermediate index regarding the ap index and can describe the general state of planetary geomagnetic activity. It contains at least two or more major sources, the auroral electrojet () and the ring current; also, by means of a multiple correlation program, a linear fit can be performed for ap in terms of AE and Dst. Furthermore, only the pair has a %corr of above 50% for any activity class. For the entire data span, the AE/ap pair performed best at 67%, followed by the pair with 59%, and the least was the pair with 37%. Additionally, the results r.evealed that the AE/ap relationship presents the highest values of 73.25%, 62.16% and 68.56% during the storm onset, main, and recovery phases, respectively.

Response to geomagnetic storm on 23–24 March 2023 long-lasting longitudinal variations of the global ionospheric TEC

This study examines the global behavior of the ionospheric TEC anomalies, i.e. their structures and temporal variability, during the initial, main and recovery phase of the geomagnetic storm occurring on 23–24 March 2023. For this purpose the global vertical TEC maps, generated by the NASA JPL IGS Ionosphere center, have been used and the geomagnetically forced anomalies have been presented in 2D (longitude-modip latitude) and polar maps. The main peculiar features of the TEC response could be summarized as: (i) the TOI-like event observed at the SH midnight hours during the main storm phase, and (ii) a clear longitude asymmetry between the TEC response at low and middle latitudes of the western and eastern hemispheres was seen; while the long-lasting positive response was evident for a full day in the western hemisphere the negative response or almost the lack of response was a characteristic of the eastern part. The study presented possible explanations of the above mentioned basic type of TEC anomalies by using the GUVY [O/N2] ratio maps and geomagnetic data from eight magnetometric stations situated at low latitudes for the separation of the effect generated by the DDEF. An attempt was made the observed TEC response during different storm phases to be reproduced. The presented reconstructions described in almost perfect way the real TEC responses and the RMSE assessments provided clear evidence for this evaluation.

Localized Magnetopause Erosion at Geosynchronous Orbit by Reconnection

AbstractThis study presents observations of magnetopause reconnection and erosion at geosynchronous orbit, utilizing in situ satellite measurements and remote sensing ground‐based instruments. During the main phase of a geomagnetic storm, Geostationary Operational Environmental Satellites (GOES) 15 was on the dawnside of the dayside magnetopause (10.6 MLT) and observed significant magnetopause erosion, while GOES 13, observing duskside (14.6 MLT), remained within the magnetosphere. Combined observations from the THEMIS satellites and Super Dual Auroral Radar Network radars verified that magnetopause erosion was primarily caused by reconnection. While various factors may contribute to asymmetric erosion, the observations suggest that the weak reconnection rate on the duskside can play a role in the formation of asymmetric magnetopause shape. This discrepancy in reconnection rate is associated with the presence of cold dense plasma on the duskside of the magnetosphere, which limits the reconnection rate by mass loading, resulting in more efficient magnetopause erosion on the dawnside.

ED‐AttConvLSTM: An Ionospheric TEC Map Prediction Model Using Adaptive Weighted Spatiotemporal Features

AbstractIn this paper, we propose a novel Total Electron Content (TEC) map prediction model, named ED‐AttConvLSTM, using a Convolutional Long Short‐Term Memory (ConvLSTM) network and attention mechanism based on encoder‐decoder structure. The inclusion of the attention mechanism enhances the efficient utilization of spatiotemporal features extracted by the ConvLSTM, emphasizing the significance of crucial spatiotemporal features in the prediction process and, as a result, leading to an enhancement in predictive performance. We conducted experiments in East Asia (10°N–45°N, 90°E−130°E). The ED‐AttConvLSTM was trained and evaluated using the International GNSS Service TEC maps over a period of six years from 2013 to 2015 (high solar activity years) and 2017 to 2019 (low solar activity years). We compared our ED‐AttConvLSTM with IRI‐2016, COPG, LSTM, GRU, ED‐ConvLSTM and ED‐ConvGRU. The results indicate that our model surpasses the comparison models in forecasting both high and low solar activity years, across most months and UT moments in a day. Moreover, our model exhibits notably superior prediction performance during the most severe phases of a magnetic storm when compared to the comparison models. Subsequently, we then also discuss how the prediction performance of our model is affected by latitude. Finally, we discuss the diminishing performance of our model in multi‐day predictions, demonstrating that its reliability for forecasts ranging from one to 4 days in advance. Beyond the fifth day, there is a pronounced decline in the model's performance.

How Solar Wind Controls the Recovery Phase Morphology of Intense Magnetic Storms

AbstractGeomagnetic storms are critical space weather phenomena resulting from the interaction between the solar wind and the Earth's magnetosphere. However, most studies focus on the main phase of magnetic storms, leaving the morphology of the recovery phase an open question. In this study, we analyze 82 intense magnetic storms with the minimum Dst index ≤ −100 nT between 1995 and 2018, finding that these storms can be classified into two distinct types: one‐stage recovery storms that exhibit a single rapid exponential recovery and two‐stage recovery storms that are characterized by a rapid exponential recovery in the early recovery phase and a slow linear recovery in the later recovery phase. We find that the two‐stage recovery storms are dominant, accounting for approximately 60% of the events. Interestingly, the proportion of two‐stage recovery storms peaks during solar minimum. The two‐stage recovery storms tend to be accompanied by more Alfvén waves with long‐duration and intense southward interplanetary magnetic fields. In addition, we find that the decay rate of the Dst index in the later recovery phase is correlated with the average BZ of the interplanetary magnetic field when the solar wind has a high degree of Alfvénicity. Overall, our results shed new light on the recovery phase morphology of intense magnetic storms and highlight the role of Alfvén waves in this process.

Ionospheric longitudinal variability in the Northern Hemisphere during magnetic storms in March 2012 from ionosonde and GPS/GLONASS data

A comprehensive study of spatio-temporal variations of geomagnetic, ionospheric, and atmospheric parameters in the middle and high latitudes of the Northern Hemisphere during a series of magnetic storms in March 2012 has been expanded by including vertical total electronic content (TEC) data from measurements at the chains of dual-frequency phase receivers GPS/GLONASS in the analysis. The features of longitudinal variations in ionosphere ionization over mid-latitude Eurasia, found earlier from vertical sounding data, are confirmed by vertical TEC data. We emphasize the complex physics of the long magnetically disturbed period in March 2012 with switching between positive and negative effects of an ionospheric storm during the same magnetic storm phases for spaced mid-latitude regions of the Eastern Hemisphere. Such changes in the ionospheric storm effects might have been caused by the superposition of competing processes in the mid-latitude region of the Eastern Hemisphere due to variations in the thermospheric composition, thermospheric winds, and large-scale electric fields affecting ionospheric ionization. We have observed significant differences in the nature of the ionospheric ionization reaction between the Eastern and Western hemispheres to the prolonged geomagnetic disturbance in March 2012. According to TEC data, there was an effect of reduced ionization of the ionosphere at longitudes of the Western Hemisphere, unlike the Eastern one. The effect of a negative ionospheric storm was caused by the formation of vast areas of atmospheric gas with a reduced density ratio [O]/[N2] over the mid-latitude region of the Western Hemisphere in the zone of maximum penetration of geomagnetic disturbances from high latitudes to middle latitudes. According to the INTERMAGNET magnetometer chain data for the analyzed period of magnetic storms on March 7–20, 2012, at midlatitudes of the Northern Hemisphere the maximum geomagnetic field variations were observed in the Western Hemisphere.

Longitudinal variations of ionospheric responses to the February and April 2023 geomagnetic storms over American and Asian sectors

This paper investigates the ionospheric responses to the February and April 2023 geomagnetic storms using Total Electron Content (TEC) derived from the 10 Global Navigation Satellite System (GNSS) stations at the transition of low to mid-latitudes (Approx. 20 ∼ 30°N) across different longitudes in the American and Asian sectors. Significant variations in both sectors were recorded during the recovery phase and were mainly attributed to the Prompt Penetration Electric Field (PPEF), Disturbance Dynamo Electric Field (DDEF) and the thermospheric neutral composition changes as O/N2 depletion. Similarly, the American and Asian sectors showed TEC enhancements, primarily attributed to the PPEF, during the main phase of the April storm. The negative TEC variations during the recovery phase were observed due to the DDEF and changes in O/N2. In the Asian sector, positive and negative variations were recorded over Pakistan and China, respectively, during the main phase of the April storm. These variations resulted in high and low concentrations of the O/N2 ratio due to Magnetosphere-Ionosphere-Thermosphere coupling.

Долготная изменчивость ионосферы северного полушария во время магнитных бурь в марте 2012 года по данным ионозондов и GPS/ГЛОНАСС

A comprehensive study of spatio-temporal variations of geomagnetic, ionospheric, and atmospheric parameters in the middle and high latitudes of the Northern Hemisphere during a series of magnetic storms in March 2012 has been expanded by including vertical total electronic content (TEC) data from measurements at the chains of dual-frequency phase receivers GPS/GLONASS in the analysis. The features of longitudinal variations in ionosphere ionization over mid-latitude Eurasia, found earlier from vertical sounding data, are confirmed by vertical TEC data. We emphasize the complex physics of the long magnetically disturbed period in March 2012 with switching between positive and negative effects of an ionospheric storm during the same magnetic storm phases for spaced mid-latitude regions of the Eastern Hemisphere. Such changes in the ionospheric storm effects might have been caused by the superposition of competing processes in the mid-latitude region of the Eastern Hemisphere due to variations in the thermospheric composition, thermospheric winds, and large-scale electric fields affecting ionospheric ionization. We have observed significant differences in the nature of the ionospheric ionization reaction between the Eastern and Western hemispheres to the prolonged geomagnetic disturbance in March 2012. According to TEC data, there was an effect of reduced ionization of the ionosphere at longitudes of the Western Hemisphere, unlike the Eastern one. The effect of a negative ionospheric storm was caused by the formation of vast areas of atmospheric gas with a reduced density ratio [O]/[N2] over the mid-latitude region of the Western Hemisphere in the zone of maximum penetration of geomagnetic disturbances from high latitudes to middle latitudes. According to the INTERMAGNET magnetometer chain data for the analyzed period of magnetic storms on March 7–20, 2012, at midlatitudes of the Northern Hemisphere the maximum geomagnetic field variations were observed in the Western Hemisphere.

Parametrization of Spatial-Energy Distributions of H+ and O+ Ions of the Ring Current on the Main Phase of Magnetic Storms

Parametrization of Spatial-Energy Distributions of H+ and O+ Ions of the Ring Current on the Main Phase of Magnetic Storms

Multi‐Instruments Observation of Ionospheric‐Thermospheric Dynamic Coupling Over Mohe (53.5°N, 122.3°E) During the April 2023 Geomagnetic Storm

AbstractThe state and variations of the Ionosphere‐Thermosphere (I‐T) system are strongly influenced by dynamical processes, with these effects being amplified during intense space environment disturbances such as geomagnetic storms, producing multi‐scale disturbance features in the I‐T system. The redistribution of energy and momentum through the dynamical processes is currently not well understood. Unfortunately, the dearth of thermospheric observations has yielded limited studies capable of monitoring and analyzing the I‐T dynamical coupling during storms using co‐located measurements. This work examines the responses of the I‐T system during the April 2023 geomagnetic storm based on high‐resolution continuous I‐T system observations at Mohe observatory, a middle latitude station. Both large‐scale features and short‐period oscillations were identified in multiple key parameters of the I‐T system. Similar disturbed patterns in thermospheric winds occurred during the main and recovery phases of the geomagnetic storm. However, the oscillation features in many parameters of the I‐T system are only observed during the main phase. The results of concurrent I‐T system observations unveil the oscillation features of thermospheric winds, temperatures, the ionospheric F2 peak height, electron density, and total electron content. These findings reveal the important influence of wind divergence on thermospheric temperature disturbances and its modulatory effect on ionospheric disturbances.

Myocardial injury in COVID-19: A case series

The COVID-19 pandemic has affected nearly millions of populations worldwide. The range of symptomatology is vast, though predominantly respiratory, and ranges from mild flu-like symptoms to severe respiratory illness with acute respiratory distress syndrome. COVID-19 is associated with many non-respiratory complications affecting the heart, kidneys, gastrointestinal system, central nervous system, and blood vessels. Myocardial injury in COVID-19 patients has varied presentations ranging from arrhythmias, myocardial infarction, myocarditis, and cardiomyopathy to cardiogenic shock. It is usually associated with elevated levels of cardiac biomarkers, with or without any changes in electrocardiography or cardiac imaging. Diagnosis may be difficult based on clinical symptoms or electrocardiogram changes alone, and it can be made using 2D echocardiography, coronary angiogram, CT coronary angiogram, or cardiac magnetic resonance imaging, depending on clinical suspicion. COVID-19-associated cardiac injury increases overall morbidity and mortality. In this case series, five COVID-19 cases with different cardiac manifestations were reported with the intention of presenting the various manifestations of cardiac complications, the course of the disease, and the challenges associated with the complications. This case series showed that cardiac complications are common in the 2nd week during the cytokine storm phase, and timely case-specific specialized diagnostic and therapeutic cardiac interventions might improve the chances of patient survival.

High Heart Rate Variability Causes Better Adaptation to the Impact of Geomagnetic Storms

Our study aimed to test whether specific sensitive reactions in healthy males to the changes in geomagnetic activity (GMA) are different depending on the baseline self-regulation of the autonomic nervous system (ANS). In this study, the ANS response in the different phases of geomagnetic storms (GMSs) has been measured via the heart rate variability (HRV) using one-way ANOVA and the Bonferroni-adjusted t-test. In the case of high HRV, changes were found to indicate a significant intensification of both parts of the ANS: the sympathetic part (SP) showed increased stress levels and the parasympathetic part (PP) marked a self-regulation effort in the main and restoration phases of GMSs. In the case of low HRV, changes indicate a significant enhancement in the SP after the main phase of GMSs, with a day’s delay. GMA is a sufficient environmental factor for healthy males, causing stress reactions of the ANS in the main and restoration phases of GMSs. However, the different self-regulation of the ANS results in different dynamics in its variation depending on the individual’s character of the baseline ANS state; the optimal adaptation reactions of healthy males with baseline high HRV are achieved with decreased heart rate and increased HRV in the main phase of GMSs.

Large Scale Traveling Ionospheric Disturbances During Geomagnetic Storms of 17 March and 23 June 2015 in the Australian Region

AbstractLarge scale traveling ionospheric disturbances (LSTIDs) can be detected using the critical frequency of F2 layer (foF2) of the ionosphere. The HF interferometry (HF‐int) technique is applied to the ionosonde data from low and mid latitude stations over Australia. For the first time, we present a comparison of TIDs detected during the geomagnetic storms of 17 March and 23 June 2015. The TID response for these two comparable superstorms is significantly different owing to the differing storm evolution patterns. The storm associated TIDs are more intense and longer compared to the solar terminator. Results demonstrate that the morphology of parameters continually varies over time due to highly dynamic ionospheric response to geomagnetic storms. For the March storms, TIDs velocities were 400–700 m/s at the onset phase, ∼500 m/s during the main phase and ∼600 m/s during the recovery phase. Their propagation directions were equatorward with east/west deviations. Lower period (∼60 min) TIDs were determined during storm onset whereas higher periods (∼140 min) were detected during the recovery phase. The June storm produced a different response. The TID velocity at the onset phase was ∼500 m/s but during the main and recovery phases the velocities were greater than 1,000 m/s. There were large deviations in velocity vectors at the different stations suggesting multiple sources of TID generation and possible resonating effects at middle and low latitude stations. Our findings indicate that while TID detection and storm phases co‐occur, the propagation characteristics of TIDs change dramatically throughout the storm.

Variability of Ionosphere Over Indian Longitudes to a Variety of Space Weather Events During December 2006

AbstractThis paper highlights the impact of intense solar events over India during 3–20 December 2006. Ionospheric effects of a major solar flare (X9) on December 5 (10:35 UT) have been investigated by using dayside and nightside magnetometer data, dayside ionosondes, and dayside GPS vTEC observations. On the next day, a stream of fast solar wind hits the magnetosphere, causing a HILDCAA (High Intensity Long Duration Continuous Auroral Activity) preceded by moderate geomagnetic storm. The origin and characteristics of a positive ionospheric storm which occurred over Tirunelveli (TIR, geomagnetic latitude: −0.18°N) in the recovery phase of storm due to simultaneous presence of enhanced O/N2 and WEJ or weakened EEJ during the HILDCAA (7th and 8th of December) is investigated. Subsequently, on December 14, the most powerful CME since the Halloween event impacts the Earth, and three SSCs are recorded on December 14, 16, and 18. The variability of the ionosphere over the Indian longitude sector due to these intense space weather fluctuations is presented by utilizing the magnetometers, ionosonde, GPS vTEC, and satellite‐based observations in the same region. This study reports the influence of prompt penetration of the magnetospheric convection electric field and the disturbance dynamo on several key ionospheric and magnetic parameters within the Indian longitude sector.

The Variation of Ionospheric O+ and H+ Outflow on Storm Timescales

AbstractGeomagnetic storms are primarily driven by stream interaction regions (SIRs) and coronal mass ejections (CMEs). Since SIR and CME storms have different solar wind and magnetic field characteristics, the magnetospheric response may vary accordingly. Using FAST/TEAMS data, we investigate the variation of ionospheric O+ and H+ outflow as a function of geomagnetic storm phase during SIR and CME magnetic storms. The effects of storm size and solar EUV flux, including solar cycle and seasonal effects, on storm time ionospheric outflow, are also investigated. The results show that for both CME and SIR storms, the O+ and H+ fluences peak during the main phase, and then declines in the recovery phase. However, for CME storms, there is also significant increase during the initial phase. Because the outflow starts during the initial phase in CME storms, there is time for the O+ to reach the plasma sheet before the start of the main phase. Since plasma is convected into the ring current from the plasma sheet during the main phase, this may explain why more O+ is observed in the ring current during CME storms than during SIR storms. We also find that outflow fluence is higher for intense storms than moderate storms and is higher during solar maximum than solar minimum.

Multiscale Magnetosphere‐Ionosphere Coupling During Stormtime: A Case Study of the Dawnside Current Wedge

AbstractA characteristic feature of the main phase of geomagnetic storms is the dawn‐dusk asymmetric depression of low‐ and mid‐latitude ground magnetic fields, with largest depression in the dusk sector. Recent work has shown, using data taken from hundreds of storms, that this dawn‐dusk asymmetry is strongly correlated with enhancements of the dawnside westward electrojet and this has been interpreted as a “dawnside current wedge” (DCW). Its ubiquity suggests it is an important aspect of stormtime magnetosphere‐ionosphere (MI) coupling. In this work we simulate a moderate geomagnetic storm to investigate the mechanisms that give rise to the formation of the DCW. Using synthetic SuperMAG indices we show that the model reproduces the observed phenomenology of the DCW, namely the correlation between asymmetry in the low‐latitude ground perturbation and the dawnside high‐latitude ground perturbation. We further show that these periods are characterized by the penetration of mesoscale bursty bulk flows (BBFs) into the dawnside inner magnetosphere. In the context of this event we find that the development of the asymmetric ring current, which inflates the dusk‐side magnetotail, leads to asymmetric reconnection and dawnward‐biased flow bursts. This results in an eastward expansion and multiscale enhancement of the dawnside electrojet. The electrojet enhancement extends across the dawn quadrant with localized enhancements associated with the wedgelet current systems of the penetrating BBFs. Finally, we connect this work with recent studies that have shown rapid, localized ground variability on the dawnside which can lead to hazardous geomagnetically induced currents.

Ionospheric response over the Middle Asian region to the May 1967 geomagnetic storm

Ionospheric effects over the five Middle Asian ionospheric stations to the major space weather event of the May 25–26, 1967 geomagnetic storm with the Dst-index of −387 nT are studied based on ionosonde measurements that were not previously considered: Alma-Ata (43.25N, 76.92E), Karaganda (49.82N, 73.08E), Novokazalinsk (45.76N, 62.12E), Tashkent (41.33N, 69.62E), Ashkhabad (37.90N, 58.30E). The study presents a description of the geomagnetic storm effects on the ionosphere electron concentration from F-region down to the lower ionosphere, points out the storm effects in different ionospheric layers for the time period 22–31 May 1967. The observations indicate a major (≥50%) and long lasting (>28 h) negative ionospheric disturbance appeared during night- and daytime simultaneously at all five stations. The daytime foF2 values on 26 May were practically at the nighttime foF2 level on this day and well below the background daytime foF2 level. A rapid increase in h’F associated with reductions in foF2 occurred over all stations during the development of the main phase of the magnetic storm. Large changes in the critical frequencies foE, foEs, and fmin that is possible linked to the enhanced X-ray flux, increased intensity in solar cosmic rays, and precipitation of energetic neutral atoms at the respective latitudes were observed during 23–26 May 1967.

Nitric oxide cooling emission during geomagnetic storm: Case studies

The Nitric Oxide (NO) emission at 5.3 µm is the dominating thermospheric coolant in the altitude above ∼ 100 km. It effectively regulates the thermospheric temperature during space weather events. We studied the diurnal response of the Nitric Oxide at 5.3 µm emission to the geomagnetic storms of different intensities by using the NO emission data from the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard NASA’s Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. We selected eight CME-driven geomagnetic storms with |SYM-H| index ranging from 0 to 500 nT. One of the storms that occurred during 19–22 November 2003 is investigated in details. Other events are used for comparison. The NO flux and the NO power during different phases of the geomagnetic storms are calculated with 24 h-time bins from the storm’s onset. The NO cooling and the cooling power are always higher during the daytime. Although the NO cooling flux and the cooling power increase with the storm intensity, they are not always higher during the stronger storms.