Effects Of Geomagnetic Storms Research Articles

Response of the Antarctic Ionosphere to Some Intense Geomagnetic Storms

Background:The effect of geomagnetic storms on the mid-high latitude F2 region is studied.Method:For this purpose, foF2 data from four Antarctic stations were analyzed during three intense magnetic storms occurred in high solar activity (years 2002 and 2003). In general, negative storm effects irrespective of the local time were observed during the first part of the storms (main phase). Negative effects were also observed more often than positive effects during the first part of the recovery phase, which seems to indicate almost no longitudinal dependence in this stage of the storm.Conclusion:The negative effects frequently changed to positive during the last stage of the recovery. Several physical mechanisms were operative during the different stages of the storms.

The effect of ring current electron scattering rates on magnetosphere‐ionosphere coupling

AbstractThis simulation study investigated the electrodynamic impact of varying descriptions of the diffuse aurora on the magnetosphere‐ionosphere (M‐I) system. Pitch angle diffusion caused by waves in the inner magnetosphere is the primary source term for the diffuse aurora, especially during storm time. The magnetic local time (MLT) and storm‐dependent electrodynamic impacts of the diffuse aurora were analyzed using a comparison between a new self‐consistent version of the Hot Electron Ion Drift Integrator with varying electron scattering rates and real geomagnetic storm events. The results were compared with Dst and hemispheric power indices, as well as auroral electron flux and cross‐track plasma velocity observations. It was found that changing the maximum lifetime of electrons in the ring current by 2–6 h can alter electric fields in the nightside ionosphere by up to 26%. The lifetime also strongly influenced the location of the aurora, but the model generally produced aurora equatorward of observations.

Ionospheric irregularities over Bahir Dar, Ethiopia during selected geomagnetic storms

We have analyzed the effect of geomagnetic storms on the occurrence of ionospheric irregularities by considering seven case studies in the period of 2013–2014 over Bahir Dar, Ethiopia (11°N, 38°E). We inferred the irregularity indices from GPS phase fluctuation by computing the median of 1-min rate of change of total electron content (fp) along the ray paths from all satellites observed. The Fp-index was calculated as an hourly average fp-index values along the ray paths from all satellites observed during each hour. Our results revealed that the irregularity level was inhibited during post sunset hours of the main phase of the storms we considered. On average, the irregularity index has dropped from 400 (0.4TECU/min) during quiet time to 50 (0.05TECU/min) on disturbed time with an amount of 350 (0.35TECU/min). However, in some of the cases, immediately after the onset of the storm, we observed the enhancement of irregularities. We found that only the observations on 01 June 2013 and 19 February 2014 exhibited a correspondence of the time of occurrence of the minimum of the Dst-index with inhibition of irregularities noted by other researchers. Our observations of the enhancement of irregularities on 17 March 2013 and 19 February 2014 can partly be explained by the orientation of the IMF BZ. Other measurements such as neutral wind, electric field are required to explain the observations on 29 June 2013, 06 July 2013, 09 November 2013 and 27 February 2014.

Total Electron Content Anomalies Before Mw 6.0+ Earthquakes in the Seismic Zone of Southwest China Between 2001 and 2013

Abstract To investigate the coupling relationship between ionospheric variations and great earthquakes in the seismic zone of southwest China, the total electron content (TEC) anomalies before Mw 6.0+ earthquakes in that area between 2001 and 2013 were analyzed to study the precursors of great earthquakes. To analyze the lithosphere-atmosphere-ionosphere effect, TEC estimated by the Center for Orbit Determination in Europe was used to determine anomalies prior to 18 moderate-to-great earthquakes with magnitudes of ≥ 6.0. Spatial and temporal TEC variations in the seismic zone were calculated and examined to study the relationship between the identified TEC anomalies and subsequent earthquakes. The results showed that ionospheric anomalies were observed before 72 % of earthquakes and among those anomalies, positive and negative anomalies accounted for approximately 58 % and 42 % of anomalies, respectively. Most of the ionospheric anomalies could be observed within 1 to 6 days prior to the earthquakes and approximately 82 % of ionospheric anomalies usually occurred between 13:00 and 18:00 in the region's local time. Furthermore, the anomaly amplitudes and occurrence time were proportional to the magnitude of the earthquake but the relationship was not linear. After eliminating the effect of solar activities and geomagnetic storms, some obvious and regular anomalous behavior in TEC could be detected on the 19th day before several earthquakes and the peak of anomaly enhancement coincided with the vertical projection of the epicenter. Our results indicate that these TEC anomalies may be the ionospheric precursors of forthcoming earthquakes in the seismic belt of southwest China.

Detection of ionospheric anomalies during intense space weather over a low-latitude GNSS station

The operational availability of Global Navigation Satellite System is affected by large-scale irregularities of the ionosphere. The space weather events induce several intense irregularities and cause the non-linear distribution of ionospheric electron density. Monitoring of ionospheric responses due to extreme space weather events plays a key role in trans-ionospheric radio wave propagation. In the present analysis, a novel technique based on wavelet transform has been implemented for the analysis and detection of ionospheric anomalies during two intense space weather events that occurred in 2013. The investigations have been carried out using the ionospheric observable, Total Electron Content (TEC), derived from the Global Positioning System (GPS) receiver located at an Equatorial Ionisation Anomaly region, KL University, Guntur, India (Geographic Lat.16.37°N, Geographic Long. 80.37°E). The effects of geomagnetic storms (Sym-H ≤ −100 nT) on the perturbations of ionospheric TEC have been investigated. The algorithm of Continuous wavelet transform has been used to study and characterise the presence of ionospheric anomalies in the local time-scale plane. It can detect spatial and temporal details of ionospheric anomaly intensity during strong solar-terrestrial and geophysical events. It is observed that during the main phase of the geomagnetic storm that occurred during 17 March 2013, TEC enhanced by 7 TECU, while a suppression of 10 TECU in the GPS-TEC can be noticed during the main phase of the 29 June 2013 storm. The variation in the intensity of ionospheric TEC anomalies during storm time has been detected and compared to the intensity of the space weather events measured through solar and geomagnetic indices (F10.7, Sym-H, IMF Bz and IEF Ey).

Relative importance of horizontal and vertical transports to the formation of ionospheric storm‐enhanced density and polar tongue of ionization

AbstractThere are still uncertainties regarding the formation mechanisms for storm‐enhanced density (SED) in the high and subauroral latitude ionosphere. In this work, we deploy the Thermosphere Ionosphere Electrodynamic General Circulation Model (TIEGCM) and GPS total electron content (TEC) observations to identify the principle mechanisms for SED and the tongue of ionization (TOI) through term‐by‐term analysis of the ion continuity equation and also identify the advantages and deficiencies of the TIEGCM in capturing high‐latitude and subauroral latitude ionospheric fine structures for the two geomagnetic storm events occurring on 17 March 2013 and 2015. Our results show that in the topside ionosphere, upward E × B ion drifts are most important in SED formation and are offset by antisunward neutral winds and downward ambipolar diffusion effects. In the bottomside F region ionosphere, neutral winds play a major role in generating SEDs. SED signature in TEC is mainly caused by upward E × B ion drifts that lift the ionosphere to higher altitudes where chemical recombination is slower. Horizontal E × B ion drifts play an essential role in transporting plasma from the dayside convection throat region to the polar cap to form TOIs. Inconsistencies between model results and GPS TEC data were found: (1) GPS relative TEC difference between storm time and quiet time has “holes” in the dayside ion convection entrance region, which do not appear in the model results. (2) The model tends to overestimate electron density enhancements in the polar region. Possible causes for these inconsistencies are discussed in this article.

Investigating the effect of geomagnetic storm and equatorial electrojet on equatorial ionospheric irregularity over East African sector

The variability of the equatorial ionosphere is still a big challenge for ionospheric dependent radio wave technology users. To mitigate the effect of equatorial ionospheric irregularity on trans-ionospheric radio waves considerable efforts are being done to understand and model the equatorial electrodynamics and its connection to the creation of ionospheric irregularity. However, the effect of the East-African ionospheric electrodynamics on ionospheric irregularity is not yet well studied due to lack of multiple ground based instruments. But, as a result of International Heliophysical Year (IHY) initiative, which was launched in 2007, some facilities are being deployed in Africa since then. Therefore, recently deployed instruments, in the Ethiopian sector, such as SCINDA-GPS receiver (2.64°N dip angle) for TEC and amplitude scintillation index (S4) data and two magnetometers, which are deployed on and off the magnetic equator, data collected in the March equinoctial months of the years 2011, 2012, and 2015 have been used for this study in conjunction with geomagnetic storm data obtained from high resolution OMNI WEB data center. We have investigated the triggering and inhibition mechanisms for ionospheric irregularities using, scintillation index (S4), equatorial electrojet (EEJ), interplanetary electric field (IEFy), symH index, AE index and interplanetary magnetic field (IMF) Bz on five selected storm and two storm free days. We have found that when the eastward EEJ fluctuates in magnitude due to storm time induced electric fields at around noontime, the post-sunset scintillation is inhibited. All observed post-sunset scintillations in equinox season are resulted when the daytime EEJ is non fluctuating. The strength of noontime EEJ magnitude has shown direct relation with the strength of the post-sunset scintillations. This indicates that non-fluctuating EEJ stronger than 20nT, can be precursor for the occurrence of the evening time ionospheric irregularities. It is also found that prolonged eastward undershielding electric field during the daytime intensified the daytime EEJ magnitude and resulted in strong post-sunset scintillations. We have also observed that the rate of change of BZ (i.e. electric field produced by Faraday’s Induction law) and eastward IEFy around the PRE hour is nicely correlated with strong post-sunset scintillations. Moreover, discussions about the causes for the appearance and disappearance of ionospheric scintillation are presented in this paper.

SuperDARN backscatter during intense geomagnetic storms

AbstractIt is often stated that high‐frequency radars experience a loss of backscatter during geomagnetic storm events. The occurrence of backscatter during 25 intense geomagnetic storms was examined using data from the Bruny Island and Kodiak radars and a superposed epoch analysis. It was found that while a reduction of backscatter occurred in the middle to far ranges, there was an increase in the amount of backscatter from close range following storm onset. Ray tracing showed that an enhanced charge density in the E region can reduce the chance of F region and increase the chance of E region backscatter. It was also shown that reduction in backscatter cannot be explained by D region absorption. Using a normalized SYM‐H value, percentage time through recovery phase can be estimated during storm progression which allows a prediction of backscatter return in real time that accounts for varying storm recovery phase duration.

Study on geomagnetic storms driving motion of 0.1–2 MeV radiation belt electrons

Using more than five years’ worth of data observed by the Instrument for the Detection of Particles (IDP) spectrometer onboard the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite, we studied the motion characteristics of energetic electrons in different regions, i.e., the inner radiation belt, the outer radiation belt, and the slot region in geomagnetic storms. We investigated the flux change of 0.1–2.4MeV electrons and the energy change of 0.1–1.0MeV electrons in these different regions. By cross correlation analysis, we came to the following conclusions. First, when Dst<−50, the correlation coefficient (c.c.) of the electron flux and Dst index ranges from −0.63 to −0.86, and the enhancement of the electron flux generally occurs during the storm’s main and recovery phases. Second, the storms greatly influence the lower energy region of the electron energy spectrum in the inner radiation belt, while the enhancement in the higher energy region is more significant in the outer radiation belt and the slot region. Third, the effects of geomagnetic storms on electrons are not distinguished significantly between in the day and night, and independent of the timing of the events. For storms with −50<Dst<−30, there is a negative correlation of −0.51 to −0.57 between the Dst index and the electron flux in the outer radiation belt. Our analysis suggests that strong storms cause energetic electron ejections across a wide range, and the ejection level is affected by the storm intensity. Furthermore, the electron energy region influenced by the strong geomagnetic storms is opposite in the inner and outer radiation belts. The proportion of electrons accelerated to relativistic energies is greater in the outer radiation and slot regions, while the ejection energetic electrons are more concentrated in the low energy region of the inner radiation belt. This phenomenon reflects the different electron injection mechanisms and accelerating processes responsible for spectral index variations in different L regions during geomagnetic storms.

Optimal interpolation analysis of high‐latitude ionospheric Hall and Pedersen conductivities: Application to assimilative ionospheric electrodynamics reconstruction

AbstractWe have developed a new optimal interpolation (OI) technique to estimate complete high‐latitude ionospheric conductance distributions from Defense Meteorological Satellite Program particle data. The technique combines particle precipitation‐based calculations of ionospheric conductances and their errors with a background model and its error covariance (modeled with empirical orthogonal functions) to infer complete distributions of the high‐latitude ionospheric conductances. We demonstrate this technique for the 26 November through 2 December 2011 period and analyze a moderate geomagnetic storm event on 30 November 2011. Quantitatively and qualitatively, this new technique provides better ionospheric conductance specification than past statistical models, especially during heightened geomagnetic activity. We provide initial evidence that auroral images from the Defense Meteorological Satellite Program Special Sensor Ultraviolet Spectrographic Imager instrument can be used to further improve the OI conductance maps. Our OI conductance patterns allow assimilative mapping of ionospheric electrodynamics reconstructions driven separately by radar and satellite magnetometer observations to be in closer agreement than when other, commonly used, conductance models are applied. This work (1) supports better use of the diverse observations available for high‐latitude ionospheric electrodynamics specification and (2) supports the Cousins et al. (2015b) assertion that more accurate models of the ionospheric conductance are needed to robustly assimilate ground‐ and space‐based observations of ionospheric electrodynamics. We find that the OI conductance distributions better capture the dynamics and locations of discrete electron precipitation that modulate the coupling of the magnetosphere‐ionosphere‐thermosphere system.

Simulation of a rapid dropout event for highly relativistic electrons with the RBE model

AbstractA flux dropout is a sudden and sizable decrease in the energetic electron population of the outer radiation belt on the time scale of a few hours. We simulated a flux dropout of highly relativistic &gt;2.5 MeV electrons using the Radiation Belt Environment model, incorporating the pitch angle diffusion coefficients caused by electromagnetic ion cyclotron (EMIC) waves for the geomagnetic storm event of 23–26 October 2002. This simulation showed a remarkable decrease in the &gt;2.5 MeV electron flux during main phase of the storm, compared to those without EMIC waves. This decrease was independent of magnetopause shadowing or drift loss to the magnetopause. We suggest that the flux decrease was likely to be primarily due to pitch angle scattering to the loss cone by EMIC waves. Furthermore, the &gt;2.5 MeV electron flux calculated with EMIC waves correspond very well with that observed from Solar Anomalous and Magnetospheric Particle EXplorer spacecraft. EMIC wave scattering is therefore likely one of the key mechanisms to understand flux dropouts. We modeled EMIC wave intensities by the Kp index. However, the calculated dropout is a several hours earlier than the observed one. We propose that Kp is not the best parameter to predict EMIC waves.

Latitudinal and Seasonal Investigations of Storm-Time TEC Variation

The ionosphere responds markedly and unpredictably to varying magnetospheric energy inputs caused by solar disturbances on the geospace. Knowledge of the impact of the space weather events on the ionosphere is important to assess the environmental effect on the operations of ground- and space-based technologies. Thus, global positioning system (GPS) measurements from the international GNSS service (IGS) database were used to investigate the ionospheric response to 56 geomagnetic storm events at six different latitudes comprising the northern and southern hemispheres in the Afro-European sector. Statistical distributions of total electron content (TEC) response show that during the main phase of the storms, enhancement of TEC is more pronounced in most of the seasons, regardless of the latitude and hemisphere. However, a strong seasonal dependence appears in the TEC response during the recovery phase. Depletion of TEC is majorly observed at the high latitude stations, and its appearance at lower latitudes is seasonally dependent. In summer hemisphere, the depletion of TEC is more pronounced in nearly all the latitudinal bands. In winter hemisphere, enhancement as well as depletion of TEC is observed over the high latitude, while enhancement is majorly observed over the mid and low latitudes. In equinoxes, the storm-time TEC distribution shows a fairly consistent characteristic with the summer distribution, particularly in the northern hemisphere.

Equatorial electrojet in the Indian region during the geomagnetic storm of 13–14 November 1998

The geomagnetic storm of November 1998 is a unique event where IMF-Bz remained southward with values exceeding –15 nT for more than a day. The SYM/H index decreased from about 07 hr on 13 November 1998 reaching a minimum of about –120 nT around midnight of 13–14 November 1998. Features of the equatorial electrojet in the Indian region are studied during the geomagnetic storm event of 13–14 November 1998, based on the geomagnetic data from the chain of observatories in India. Sudden northward turning of IMF-Bz for a very short duration around 08 hr on 13 November 1998 resulted in a small and very short duration counter electrojet. A strong (–50 nT) and a long duration counter electrojet, right from 08 to 13 hr on 14 November 1998 was observed resulting in the absence of equatorial Es at Thumba. Absence of the equatorial ionization anomaly was also observed as seen from the ionograms over Thumba and ionspheric data from Ahmedabad. The delayed effect on 14 November 1998 is due to the disturbance dynamo effect.

F2 region response to geomagnetic disturbances across Indian latitudes: O(1S) dayglow emission

AbstractThe morphology of ionospheric storms has been investigated across equatorial and low latitudes of Indian region. The deviation in F2 region characteristic parameters (foF2 and h′F) along with modeled green line dayglow emission intensities is examined at equatorial station Thiruvananthapuram (8.5°N, 76.8°E, 0.63°S geomagnetic latitude) and low‐latitude station Delhi (28.6°N, 77.2°E,19.2°N geomagnetic latitude) during five geomagnetic storm events. Both positive and negative phases have been noticed in this study. The positive storm phase over equatorial station is found to be more frequent, while the drop in ionization in most of the cases was observed at low‐latitude station. It is concluded that the reaction as seen at different ionospheric stations may be quite different during the same storm depending on both the geographic and geomagnetic coordinates of the station, storm intensity, and the storm onset time. Modulation in the F2 layer critical frequency at low and equatorial stations during geomagnetic disturbance of 20–23 November 2003 was caused by the storm‐induced changes in O/N2. It is also found that International Reference Ionosphere 2012 model predicts the F2 layer characteristic (foF2 and h′F) parameters at both the low and equatorial stations during disturbed days quite reasonably. A simulative approach in GLOW model developed by Solomon is further used to estimate the changes in the volume emission rate of green line dayglow emission under quiet and strong geomagnetic conditions. It is found that the O(1S) dayglow thermospheric emission peak responds to varying geomagnetic conditions.

Effects of mid-latitude geomagnetic storms on ionospheric Total Electron Content over South Africa

The development of regional ionospheric Total Electron Content (TEC) models has contributed to understanding the behaviour of the ionosphere and the coupling of the ionosphere to space weather activities on both local and global scales. In the past several decades, the International Global Navigation Satellite Systems (IGS) Service networks of dual frequency receiver data have been applied to construct global and regional models of ionospheric TEC. These models were mainly developed in the Northern Hemisphere where there is a dense network of ground based GNSS receivers for regional data coverage. Such efforts have been historically rare over the African region, and have only recently been initiated. This study reports on the investigation of the effect of mid-latitude geomagnetic storms on TEC over South Africa for selected epochs of Solar Cycles 23 and 24. The MAGIC package was used to estimate TEC over South Africa during Post Solar Maximum, Solar Minimum, and Post Solar Minimum epochs. It is found that TEC is largely determined by the diurnal cycle of solar forcing and subsequent relaxation, but effects due to storms can be determined.

Using citizen science reports to define the equatorial extent of auroral visibility

AbstractAn aurora may often be viewed hundreds of kilometers equatorward of the auroral oval owing to its altitude. As such, the NOAA Space Weather Prediction Center (SWPC) Aurora Forecast product provides a “view line” to demonstrate the equatorial extent of auroral visibility, assuming that it is sufficiently bright and high in altitude. The view line in the SWPC product is based upon the latitude of the brightest aurora, for each hemisphere, as specified by the real‐time oval variation, assessment, tracking, intensity, and online nowcasting (OVATION) Prime (2010) aurora precipitation model. In this study, we utilize nearly 500 citizen science auroral reports to compare with the view line provided by an updated SWPC aurora forecast product using auroral precipitation data from OVATION Prime (2013). The citizen science observations were recorded during March and April 2015 using the Aurorasaurus platform and cover one large geomagnetic storm and several smaller events. We find that this updated SWPC view line is conservative in its estimate and that the aurora is often viewable further equatorward than is indicated by the forecast. By using the citizen reports to modify the scaling parameters used to link the OVATION Prime (2013) model to the view line, we produce a new view line estimate that more accurately represents the equatorial extent of visible aurora. An OVATION Prime (2013) energy flux‐based equatorial boundary view line is also developed and is found to provide the best overall agreement with the citizen science reports, with an accuracy of 91%.

An Empirical Model for the Ionospheric Global Electron Content Storm-Time Response

By analyzing the variations of global electron content (GEC) during geomagnetic storm events, the ratio “GEC/GECQT” is found to be closely correlated with geomagnetic Kp index and time weighted Dst index, where GECQT is the quiet time reference value. Moreover, the GEC/GECQT will decrease with the increase of the solar flux F10.7 index. Furthermore, we construct a linear model for storm-time response of GEC. Eighty-two storm events during 1999–2011 were utilized to calculate the model coefficients, and the performance of the model was tested using data of 8 storm events in 2012 by comparing the outputs of the model with the observed GEC values. Results suggest that the model can capture the characteristics of the GEC variation in response to magnetic storms. The component describing the solar activity influence shows a counteracting effect with the geomagnetic activity component; and the influence of Kp index causes an increase of GEC, while the time weighted Dst index causes a decrease of GEC.

GEM‐CEDAR challenge: Poynting flux at DMSP and modeled Joule heat

AbstractPoynting flux into the ionosphere measures the electromagnetic energy coming from the magnetosphere. This energy flux can vary greatly between quiet times and geomagnetic active times. As part of the Geospace Environment Modeling‐coupling energetics and dynamics of atmospheric regions modeling challenge, physics‐based models of the 3‐D ionosphere and ionospheric electrodynamics solvers of magnetosphere models that specify Joule heat and empirical models specifying Poynting flux were run for six geomagnetic storm events of varying intensity. We compared model results with Poynting flux values along the DMSP‐15 satellite track computed from ion drift meter and magnetic field observations. Although being a different quantity, Joule heat can in practice be correlated to incoming Poynting flux because the energy is dissipated primarily in high latitudes where Poynting flux is being deposited. Within the physics‐based model group, we find mixed results with some models overestimating Joule heat and some models agreeing better with observed Poynting flux rates as integrated over auroral passes. In contrast, empirical models tend to underestimate integrated Poynting flux values. Modeled Joule heat or Poynting flux patterns often resemble the observed Poynting flux patterns on a large scale, but amplitudes can differ by a factor of 2 or larger due to the highly localized nature of observed Poynting flux deposition that is not captured by the models. In addition, the positioning of modeled patterns appear to be randomly shifted against the observed Poynting flux energy input. This study is the first to compare Poynting flux and Joule heat in a large variety of models of the ionosphere.

The effects of the big storm events in the first half of 2015 on the radiation belts observed by EPT/PROBA-V

Abstract. With the energetic particle telescope (EPT) performing with direct electron and proton discrimination on board the ESA satellite PROBA-V, we analyze the high-resolution measurements of the charged particle radiation environment at an altitude of 820 km for the year 2015. On 17 March 2015, a big geomagnetic storm event injected unusual fluxes up to low radial distances in the radiation belts. EPT electron measurements show a deep dropout at L &gt; 4 starting during the main phase of the storm, associated to the penetration of high energy fluxes at L &lt; 2 completely filling the slot region. After 10 days, the formation of a new slot around L = 2.8 for electrons of 500–600 keV separates the outer belt from the belt extending at other longitudes than the South Atlantic Anomaly. Two other major events appeared in January and June 2015, again with injections of electrons in the inner belt, contrary to what was observed in 2013 and 2014. These observations open many perspectives to better understand the source and loss mechanisms, and particularly concerning the formation of three belts.

Relationship between X-class Flares and Geomagnetic Effects

A statistical study has been performed on all the geomagnetic storm events caused by Coronal Mass Ejections (CMEs) which are associated with flares from January 2010 to December 2012. The following results are obtained. The sources of the CMEs mentioned above are distributed mainly from 45°E to 45°W on the solar surface, accounting 78.95% of the total events, and most of them are distributed in the western hemisphere, thus the sources of CMEs located in the western hemisphere are more likely to cause geomagnetic effects. The X-class flares are more likely to be associated with geomagnetic effects, and geomagnetic storms will be observed in two or three days after the eruption of 60% of X-class flares, while the flares of other classes have a much lower probability to associate with geomagnetic effects, less than 10% for all of them. By analyzing all the X-class flares erupted during this period on the solar disk, it is found that for the X-class flares located from 45°E to 45°W in heliographic longitude, if there are no large-scale disturbances on the solar surface nor the accompanied CMEs during the eruptions, the probability of occurrence of geomagnetic storms after the flares will be very small. Therefore, a new method to forecast the geomagnetic storms by analyzing the observed solar image data has been proposed.