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Nandita Srivastava

Publications and source records attributed to Nandita Srivastava.

At least 19 recordsLinked to original sources
arXiv2026

Source Surface Height Optimisation for Improved Solar Wind Velocity Forecasting Across Solar Cycles 23, 24 and 25

The potential field source surface (PFSS) model is a cornerstone of many state-of-the-art space weather forecasting frameworks. It includes a single physical free parameter, the source surface (SS) height. Traditionally, a fixed SS height of 2.5 solar radii has been adopted in most studies. However, several studies have investigated the SS height in the PFSS model using various datasets and temporal intervals. Earlier efforts primarily aimed to improve estimates of the heliospheric open magnetic flux. Our recent study Kumar et al. (2025), showed that optimising the SS height substantially improves the performance of the Wang Sheeley Arge (WSA) solar wind speed prediction model at L1. That analysis employed two types of GONG synoptic magnetic field maps, namely standard (STD) and zero-point-corrected (ZPC) maps, over selected periods of solar cycles (SCs) 24 and 25. In this study, we perform a comprehensive investigation of SCs 23 to 25 using synoptic magnetic field maps derived from ground-based (GONG) and space-based (SDO/HMI) observatories. Our results demonstrate that optimising the SS height in the PFSS model significantly improves the WSA model performance compared to the commonly adopted fixed SS height. We find that during solar minimum, higher SS heights (less than or equal to 2.5 solar radii) yield better solar wind speed predictions at L1, whereas during active phases the opposite trend is observed. Although the absolute optimised SS height varies across SCs, the overall distribution pattern remains similar. These finding suggests a relationship between SS height and SC phase over long time scales. Overall, the SS height optimisation enhances the background solar wind speed prediction models in the heliosphere.

astro-ph.SR↗
arXiv2026

Three-Phase Evolution of Aspect Ratio in Fast and Slow CMEs from the Sun to 1 AU

Coronal mass ejections (CMEs) undergo significant geometric evolution as they propagate from the Sun to 1 AU, influencing their radial size, expansion, and space weather impact. We investigate the evolution of CME aspect ratio and expansion dynamics for four fast and four slow Earth-directed CMEs. Using multipoint coronagraphic observations with the Graduated Cylindrical Shell (GCS) model and corrected in situ measurements of associated magnetic clouds (MCs) at 1 AU, we track the evolution of aspect ratio from the low-middle corona to interplanetary space. We find that aspect ratio does not remain constant but exhibits a systematic three-phase evolution: a rise phase in the low-middle corona ($\lesssim10$-$15\,R_{\odot}$), a saturation phase at intermediate heights, and then a decline phase in the interplanetary space. The ratio of radial expansion speed to leading-edge speed ($V_{\rm exp}/V_{\rm LE}$) decreases substantially from the corona to 1 AU, indicating a reduction in radial expansion efficiency during interplanetary propagation. The consistent evolution of aspect ratio and $V_{\rm exp}/V_{\rm LE}$ suggests a transition from magnetically dominated expansion in the corona to a regime increasingly controlled by the heliospheric environment. We note that fast CMEs show stronger early expansion and evolve into larger, more radially extended structures, whereas slow CMEs exhibit a more gradual rise and a steeper decline. These results demonstrate that CME geometry evolves significantly during propagation and highlight the need to incorporate aspect ratio evolution in models to improve predictions of CME size, arrival time, and geoeffectiveness.

astro-ph.SR↗
arXiv2026

Propagation Characteristics of the April 21, 2023 CME

Accurate estimation of propagation characteristics of coronal mass ejections (CMEs) is crucial for predicting their geoeffectiveness. Stereoscopic techniques to study the kinematics of CMEs generally have been carried out using remote sensing observations from three viewpoints, i.e. STEREO-A, STEREO-B, and SOHO. Since the loss of STEREO-B in 2014, stereoscopic reconstruction of CMEs has been restricted to the observations from only two viewpoints, i.e., STEREO-A and SOHO. When the angle of separation between STEREO-A and SOHO is small, it leads to larger uncertainties in the CME kinematics derived using stereoscopic techniques. In this paper, we demonstrate how this limitation can be addressed and how uncertainties in the estimation of CME kinematics and propagation direction can be reduced. For this purpose, we selected the CME of April 21, 2023, which was observed by two spacecraft, i.e. STEREO-A and SOHO, separated by a small 10 degree angle. Using the Graduated Cylindrical Shell (GCS) model on the remote-sensing observations near the Sun and the Advanced Drag-Based Model (ADBM) in the heliosphere, we estimated the arrival time of the CME at different locations in the heliosphere and compared it with the actual arrival time obtained from the in-situ measurements taken by three spacecraft, BepiColombo, STEREO-A and Wind. Our analysis reveals a directional uncertainty of approx 20 degree from observations from two viewpoints. These uncertainties significantly affect the arrival-time prediction of the CME. We consider the actual chronology of CME arrival times at STEREO-A and Wind as critical parameters to constrain the direction of propagation, which serves as a key input in the ADBM. The chronology of arrival of the CME ejecta at STEREO-A, which is 4.5 hrs earlier than at Wind, proved essential for resolving directional ambiguities in the GCS reconstruction model

astro-ph.SR↗
arXiv2025

Multi-directional investigations on quiet time suprathermal ions measured by ASPEX-STEPS on-board Aditya L1

The origin, acceleration and anisotropy of suprathermal ions in the interplanetary medium during quiet periods have remained poorly understood issues in solar wind physics. To address these aspects, we derive the spectral indices for the quiet time suprathermal ions based on the measurements by the four directionally separated sensors that are part of the Supra-Thermal and Energetic Particle Spectrometer (STEPS) of Aditya Solar Wind Particle EXperiment (ASPEX) on-board Aditya L1 spacecraft. Three out of four STEPS sensors Parker Spiral (PS), Inter-Mediate (IM), Earth Pointing (EP) are in one plane (nearly aligned with the ecliptic plane) while the fourth sensor North Pointing (NP) is in a mutually orthogonal plane. The energy ranges covered by the PS, IM, EP and NP sensors are 0.36-1.32 MeV, 0.14-1.22 MeV, 0.39-1.33 MeV and 0.12-1.23 MeV respectively. The quiet intervals are identified during January November, 2024 and the derived spectral indices (differential directional flux versus energy) are found to be in the range of 2.0 for all directions in the time scale of a few days revealing isotropic nature of their distribution. Further analysis of elemental abundance ratios (3He/4He, Fe/O, and C/O) during the same quiet intervals obtained from the Ultra-Low Energy Isotope Spectrometer (ULEIS) on board the Advanced Composition Explorer (ACE) spacecraft suggests possible contributions from the leftover ions from the previous impulsive (Solar flares) and gradual events (CMEs) in the quiet time suprathermal ion pool.

physics.space-ph↗
arXiv2025

Energetic ($<$ 2 MeV) ion fluxes measured by ASPEX-STEPS on board Aditya-L1 during its earth-bound phase

During its earth-bound phase of the Aditya-L1 spacecraft of India, the Supra-Thermal and Energetic Particle Spectrometer (STEPS) of the Aditya Solar wind Particle EXperiment (ASPEX) was operated whenever the orbit was above 52000 km during 11 - 19 September 2023. This phase of operation provided measurements of energetic ions (with energies 0.1--2 MeV) in the magnetosphere, magnetosheath, and interplanetary medium. Three interplanetary coronal mass ejections (ICME) hit the magnetosphere during this period. This provided opportunity to examine the relative roles of ICME-generated solar energetic particles (SEPs) and substorm generated energetic ions on the magnetosphere. We approach this objective by detailed spectral analyses of energetic ion fluxes measured by two units of ASPEX-STEPS. We identify three distinctly different conditions of the north-south component of the interplanetary magnetic field (IMF $B_z$ = 0, $>$ 0, and $<$ 0) and use the derived spectral indices to understand this relative role. By combining these with the simultaneous energetic ion flux variations from the Advanced Composition Explorer (ACE) around the Sun-Earth first Lagrangian (L1) point and the Geostationary Operational Environmental Satellite (GOES) in the Earth's magnetosphere, we show that the polarity of IMF $B_z$ influences the energetic ion spectra in the magnetosphere by modulating the interplay of the ICME-generated SEP with the energetic particles generated inside the magnetosphere by substorms. Interestingly, ASPEX-STEPS observations also indicate towards directional anisotropy based on spectral indices. This suggests spatially inhomogeneous mixing of energetic ions coming from different source processes.

physics.space-ph↗
arXiv2024

On The Influence Of The Solar Wind On The Propagation Of Earth-impacting Coronal Mass Ejections

Coronal Mass Ejections (CMEs) are subject to changes in their direction of propagation, tilt, and other properties as they interact with the variable solar wind. We investigated the heliospheric propagation of 15 Earth-impacting CMEs observed during April 2010 to August 2018 in the field of view (FOV) of the Heliospheric Imager (HI) onboard the STEREO. About half of the 15 events followed self-similar expansion up to 40 $R_\odot$. The remaining events showed deflection either in latitude, longitude, or a tilt change. Only two events showed significant rotation in the HI1 FOV. We also use toroidal and cylindrical flux rope fitting on the in situ observations of interplanetary magnetic field (IMF) and solar wind parameters to estimate the tilt at L1 for these two events. Although the sample size is small, this study suggests that CME rotation is not very common in the heliosphere. We attributed the observed deflections and rotations of CMEs to a combination of factors, including their interaction with the ambient solar wind and the influence of the ambient magnetic field. These findings contribute to our understanding of the complex dynamics involved in CME propagation and highlight the need for comprehensive modeling and observational studies to improve space weather prediction. In particular, HI observations help us to connect observations near the Sun and near Earth, improving our understanding of how CMEs move through the heliosphere.

astro-ph.SR↗
arXiv2024

Investigation on upstream ion events from L1 point observation: New Insights

Origin of energetic upstream ions propagating towards the Sun from the Earth's bow shock is not understood clearly. In this letter, relationship between solar wind suprathermal and upstream ions has been investigated by analyzing fluxes of H, 4He, and CNO obtained from multidirectional in-situ measurements at the first Lagrange point of the Sun-Earth system during 2012-2014. 49 upstream events have been selected based on flux enhancements of the upstream ions in comparison with the solar wind suprathermal ions. An energy cut-off at less than 300 keV is observed for the upstream events. This is attributed to the efficacy of the particle acceleration process near the bow shock. Interestingly, spectra of upstream ions soften systematically as compared to the spectra of their solar wind counterpart with decreasing mass of elements. The degree of spectral softening increases with decreasing mass-to-charge ratio of the species. Since during most of the events the interplanetary magnetic field was radial, we argue that cross-field diffusion of upstream ions gives rise to the modulation (spectral softening) of upstream ions, which is dependent on the mass-to-charge ratio of species. Our work indicates towards a systematic change in solar wind suprathermal ions after interaction with the bow shock.

astro-ph.SR↗
arXiv2024

Origins of Very Low Helium Abundance Streams Detected in the Solar Wind Plasma

The abundance of helium ($A_{He}$) in the solar wind exhibits variations typically in the range from 2-5% with respect to solar cycle activity and solar wind velocity. However, there are instances where the observed $A_{He}$ is exceptionally low ($<$ 1%). These low-$A_{He}$ occurrences are detected both near the Sun and at 1 AU. The low $A_{He}$ events are generally observed near the heliospheric current sheet. We analyzed 28 low-$A_{He}$ events observed by the Wind spacecraft and 4 by Parker Solar Probe (PSP) to understand their origin. In this work, we make use of the ADAPT-WSA model to derive the sources of our events at the base of the solar corona. The modeling suggests that the low-$A_{He}$ events originated from the boundaries of coronal holes, primarily from large quiescent helmet streamers. We argue that the cusp above the core of the streamer can produce such very low helium abundance events. The streamer core serves as an ideal location for gravitational settling to occur as demonstrated by previous models, leading to the release of this plasma through reconnection near the cusp, resulting in low $A_{He}$ events. Furthermore, observations from Ulysses provide direct evidence that these events originated from coronal streamers.

astro-ph.SR↗
arXiv2024

Modelling the magnetic vectors of ICMEs at different heliocentric distances with INFROS

The INterplanetary Flux ROpe Simulator (INFROS) is an observationally constrained analytical model dedicated for forecasting the strength of the southward component (Bz) of the magnetic field embedded in interplanetary coronal mass ejections (ICMEs). In this work, we validate the model for six ICMEs sequentially observed by two radially-aligned spacecraft positioned at different heliocentric distances. The six selected ICMEs in this study comprise of cases associated with isolated CME evolution as well as those interacting with high-speed streams (HSS) and high-density streams (HDS). For the isolated CMEs, our results show that the model outputs at both the spacecraft are in good agreement with in-situ observations. However, for most of the interacting events, the model correctly captures the CME evolution only at the inner spacecraft. Due to the interaction with HSS and HDS, which in most cases occurred at heliocentric distances beyond the inner spacecraft, the ICME evolution no longer remains self-similar. Consequently, the model underestimates the field strength at the outer spacecraft. Our findings indicate that constraining the INFROS model with inner spacecraft observations significantly enhances the prediction accuracy at the outer spacecraft for the three events undergoing self-similar expansion, achieving a 90 % correlation between observed and predicted Bz profiles. This work also presents a quantitative estimation of the ICME magnetic field enhancement due to interaction which may lead to severe space weather. We conclude that the assumption of self-similar expansion provides a lower limit to the magnetic field strength estimated at any heliocentric distance, based on the remote sensing observations.

astro-ph.SR↗
arXiv2023

Photospheric Lorentz force changes in eruptive and confined solar flares

Solar flares are known to leave imprints on the magnetic field at the photosphere, often manifested as an abrupt and permanent change in the downward-directed Lorentz force in localized areas inside the active region. Our study aims to differentiate eruptive and confined solar flares based on the vertical Lorentz force variations. We select 26 eruptive and 11 confined major solar flares (stronger than the GOES M5 class) observed during 2011-2017. We analyze these flaring regions using SHARP vector-magnetograms obtained from the NASA's Helioseismic and Magnetic Imager (HMI). We also compare data corresponding to 2 synthetic flares from a $δ$--sunspot simulation reported in Chatterjee et al. [Phys. Rev. Lett. 116, 101101 (2016)]. We estimate the change in the horizontal magnetic field and the total Lorentz force integrated over an area around the polarity inversion line (PIL) that encompasses the location of the flare. Our results indicate a rapid increase of the horizontal magnetic field along the flaring PIL, accompanied by a significant change in the downward-directed Lorentz force in the same vicinity. Notably, we find that all the confined events under study exhibit a total change in Lorentz force of < $1.8 \times 10^{22}$ dyne. This threshold plays an important factor in effectively distinguishing eruptive and confined flares. Further, our analysis suggests that the change in total Lorentz force also depends on the reconnection height in the solar corona during the associated flare onset. The results provide significant implications for understanding the flare-related upward impulse transmission for the associated coronal mass ejection.

astro-ph.SR↗
arXiv2023

Rotation of a Stealth CME on 2012 October 5 Observed in the Inner Heliosphere

Coronal Mass Ejections (CMEs) are subject to changes in their direction of propagation, tilt, and other properties. This is because CMEs interact with the ambient solar wind and other large-scale magnetic field structures. In this work, we report on the observations of the 2012 October 5 stealth CME using coronagraphic and heliospheric images. We find clear evidence of a continuous rotation of the CME, i.e., an increase in the tilt angle, estimated using the Graduated Cylindrical Shell (GCS) reconstruction at different heliocentric distances, up to 58 solar radii. We find a further increase in the tilt at L1 estimated from the toroidal and cylindrical flux rope fitting on the in situ observations of IMF and solar wind parameters. This study highlights the importance of observations of Heliospheric Imager (HI), onboard the Solar TErrestrial RElations Observatory (STEREO). In particular, the GCS reconstruction of CMEs in HI field-of-view promises to bridge the gap between the near-Sun and in-situ observations at the L1. The changes in the CME tilt has significant implications for the space weather impact of stealth CMEs.

astro-ph.SR↗
arXiv2023

Suprathermal population associated with stream interaction regions observed by STEREO-A: New insights

Stream interaction regions (SIRs) are often thought to be responsible for the generation of suprathermal population in the interplanetary medium. Despite the source being same, wide variations in spectral indices of suprathermal populations are observed at 1 au during SIRs. This poses significant uncertainty in understanding the generation of suprathermal ion populations by SIRs and indicates interplay of multiple source mechanisms. In the present work, by analyzing variations in suprathermal 4He, O, and Fe for 20 SIR events recorded by STEREO-A during 2007 - 2014, we find that the spectral indices of these elements vary in the range of 2.06-4.08, 1.85-4.56, and 2.11-4.04 respectively for 19 events. However, in one special case, all the three suprathermal elements show nearly identical (1.5) spectral indices. We offer possible mechanisms, which can cause significant variations in the spectral indices of suprathermal particles. More importantly, we show the possible role of merging and/or contraction of small-scale magnetic islands near 1 au in producing nearly identical spectral indices for three different elements with different first ionization potential and mass-to-charge ratio. The occurrence of these magnetic islands near 1 au also supports the minimal modulation in spectral indices of these particles. The role of a possible solar flare in generating these magnetic islands near the heliospheric current sheet is also suggested.

astro-ph.SR↗
arXiv2023

New insights on the behaviour of solar wind protons and alphas in the Stream Interaction Region in solar cycle 23 and 24

Although the enhancements in the alpha-proton ratio in the solar wind (expressed as $A_{He} = N_a/N_p*100$) in the Interplanetary Coronal Mass Ejections (ICMEs) have been studied in the past, $A_{He}$ enhancements at the stream interface region received very little attention so far. In this letter, by extensively analyzing the stream interaction region (SIR) events observed in solar cycle 23 and 24, we show that the stream interface of alphas starts separating out from that of protons from the minimum of solar cycle 23. The population of alpha particles are enhanced compared to protons at higher angles between bulk velocity and local magnetic field (henceforth, bulk velocity angle) in the fast wind region of SIRs if the background solar wind is taken as reference. The analysis of differential velocities between alphas and protons also reveals that the faster alpha particles accumulate near the fast wind side of the stream interface region leading to enhancement of $A_{He}$. The investigation brings out, for the first time, the salient changes in $A_{He}$ in SIRs for the two solar cycles and highlight the importances of bulk velocity angle and differential velocity in the fast wind region for the changes in $A_{He}$ in SIRs.

astro-ph.SR↗
arXiv2022

A Comparative Analysis of Machine-learning Models for Solar Flare Forecasting: Identifying High-performing Active Region Flare Indicators

Solar flares create adverse space weather impacting space and Earth-based technologies. However, the difficulty of forecasting flares, and by extension severe space weather, is accentuated by the lack of any unique flare trigger or a single physical pathway. Studies indicate that multiple physical properties contribute to active region flare potential, compounding the challenge. Recent developments in machine learning (ML) have enabled analysis of higher-dimensional data leading to increasingly better flare forecasting techniques. However, consensus on high-performing flare predictors remains elusive. In the most comprehensive study to date, we conduct a comparative analysis of four popular ML techniques (k-nearest neighbor, logistic regression, random forest classifier, and support vector machine) by training these on magnetic parameters obtained from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) for the entirety of solar cycle 24. We demonstrate that the logistic regression and support vector machine algorithms perform extremely well in forecasting active region flaring potential. The logistic regression algorithm returns the highest true skill score of $0.967 \pm 0.018$, possibly the highest classification performance achieved with any strictly parametric study. From a comparative assessment, we establish that the magnetic properties like total current helicity, total vertical current density, total unsigned flux, R_VALUE, and total absolute twist are the top-performing flare indicators. We also introduce and analyze two new performance metrics, namely, severe and clear space weather indicators. Our analysis constrains the most successful ML algorithms and identifies physical parameters that contribute most to active region flare productivity.

astro-ph.SR↗
arXiv2022

Differential behaviors of suprathermal $^4$He and Fe populations in the interplanetary medium during solar cycle 24

Investigations on the solar cycle variation of the properties of suprathermal populations (H and other heavy ions like $^4$He, $^3$He, C, O and Fe) in the solar wind are sparse and hence, poorly understood. In the present investigation, solar cycle variations of "quiet" time suprathermal elements are investigated using $<$ $\sim$ 1 MeV/n particle flux data obtained from Ultra-Low Energy Isotope Spectrometer on board Advanced Composition Explorer satellite during the solar cycle 23 and 24. The analysis reveals that helium ($^4$He) shows zero or positive lags with respect to sunspot numbers in solar cycle 23 while it shows zero or negative lag in solar cycle 24. On the contrary, although iron (Fe) shows zero or positive lag in cycle 23 similar to $^4$He, it shows only zero lag in cycle 24 and no negative lag is seen. Further, significant differences in the spectral indices are seen between $^4$He and Fe in cycle 24 compared to the cycle 23. These results suggest that generation mechanisms responsible for suprathermal $^4$He and Fe underwent changes in cycle 24 and these mechanisms are probably dependent on the first ionization potential and mass to charge ratio. This proposition gets credence from the fact that changes in the lag and spectral slopes for C and O are not significantly different in cycle 23 and 24.

astro-ph.SR↗
arXiv2021

Understanding the Origins of Problem Geomagnetic Storms Associated With "Stealth" Coronal Mass Ejections

Geomagnetic storms are an important aspect of space weather and can result in significant impacts on space- and ground-based assets. The majority of strong storms are associated with the passage of interplanetary coronal mass ejections (ICMEs) in the near-Earth environment. In many cases, these ICMEs can be traced back unambiguously to a specific coronal mass ejection (CME) and solar activity on the frontside of the Sun. Hence, predicting the arrival of ICMEs at Earth from routine observations of CMEs and solar activity currently makes a major contribution to the forecasting of geomagnetic storms. However, it is clear that some ICMEs, which may also cause enhanced geomagnetic activity, cannot be traced back to an observed CME, or, if the CME is identified, its origin may be elusive or ambiguous in coronal images. Such CMEs have been termed "stealth CMEs." In this review, we focus on these "problem" geomagnetic storms in the sense that the solar/CME precursors are enigmatic and stealthy. We start by reviewing evidence for stealth CMEs discussed in past studies. We then identify several moderate to strong geomagnetic storms (minimum Dst < -50 nT) in solar cycle 24 for which the related solar sources and/or CMEs are unclear and apparently stealthy. We discuss the solar and in situ circumstances of these events and identify several scenarios that may account for their elusive solar signatures. These range from observational limitations (e.g., a coronagraph near Earth may not detect an incoming CME if it is diffuse and not wide enough) to the possibility that there is a class of mass ejections from the Sun that have only weak or hard-to-observe coronal signatures. In particular, some of these sources are only clearly revealed by considering the evolution of coronal structures over longer time intervals than is usually considered. We also review a variety of numerical modelling approaches...

astro-ph.SR↗
arXiv2021

Investigating Remote-sensing Techniques to Reveal Stealth Coronal Mass Ejections

Eruptions of coronal mass ejections (CMEs) from the Sun are usually associated with a number of signatures that can be identified in solar disc imagery. However, there are cases in which a CME that is well observed in coronagraph data is missing a clear low-coronal counterpart. These events have received attention during recent years, mainly as a result of the increased availability of multi-point observations, and are now known as 'stealth CMEs'. In this work, we analyse examples of stealth CMEs featuring various levels of ambiguity. All the selected case studies produced a large-scale CME detected by coronagraphs and were observed from at least one secondary viewpoint, enabling a priori knowledge of their approximate source region. To each event, we apply several image processing and geometric techniques with the aim to evaluate whether such methods can provide additional information compared to the study of "normal" intensity images. We are able to identify at least weak eruptive signatures for all events upon careful investigation of remote-sensing data, noting that differently processed images may be needed to properly interpret and analyse elusive observations. We also find that the effectiveness of geometric techniques strongly depends on the CME propagation direction with respect to the observers and the relative spacecraft separation. Being able to observe and therefore forecast stealth CMEs is of great importance in the context of space weather, since such events are occasionally the solar counterparts of so-called 'problem geomagnetic storms'.

astro-ph.SR↗
arXiv2019

An Observationally Constrained Analytical Model for Predicting the Magnetic Field Vectors of ICMEs at 1 AU

We report on an observationally constrained analytical model, the INterplanetary Flux ROpe Simulator (INFROS), for predicting the magnetic-field vectors of coronal mass ejections (CMEs) in the interplanetary medium. The main architecture of INFROS involves using the near-Sun flux rope properties obtained from the observational parameters that are evolved through the model in order to estimate the magnetic field vectors of interplanetary CMEs (ICMEs) at any heliocentric distance. We have formulated a new approach in INFROS to incorporate the expanding nature and the time-varying axial magnetic field-strength of the flux rope during its passage over the spacecraft. As a proof of concept, we present the case study of an Earth-impacting CME which occurred on 2013 April 11. Using the near-Sun properties of the CME flux rope, we have estimated the magnetic vectors of the ICME as intersected by the spacecraft at 1 AU. The predicted magnetic field profiles of the ICME show good agreement with those observed by the in-situ spacecraft. Importantly, the maximum strength (10.5 $\pm$ 2.5 nT) of the southward component of the magnetic field (Bz) obtained from the model prediction, is in agreement with the observed value (11 nT). Although our model does not include the prediction of the ICME plasma parameters, as a first order approximation it shows promising results in forecasting of Bz in near real time which is critical for predicting the severity of the associated geomagnetic storms. This could prove to be a simple space-weather forecasting tool compared to the time-consuming and computationally expensive MHD models.

astro-ph.SR↗