A5083696994- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Spacecraft and Cryogenic Technologies
- Atmospheric Ozone and Climate
- Astro and Planetary Science
- Magnetic confinement fusion research
University of Mumbai
2023-2024
Interplanetary coronal mass ejections (ICME) are large-scale eruptions from the Sun and prominent drivers of space weather disturbances, especially intense/extreme geomagnetic storms. Recent studies by our group showed that ICME sheaths and/or magnetic clouds (MC) could be transformed into a planar structure (PMS) speculate these structures might more geo-effective. Thus, we statistically investigated geo-effectiveness non-planar MC regions. We analyzed 420 events observed 1998 to 2017,...
Alfv\'en waves (AWs) are inevitable in space and astrophysical plasma. Their crucial role various physical processes, occurring plasma, has triggered intense research solar-terrestrial physics. Simulation studies have proposed the generation of AWs along surface a cylindrical flux rope, referred to as Surface (SAWs); however observational verification this distinct wave been elusive date. We report first \textit{in-situ} observation SAWs an interplanetary coronal mass ejection rope. apply...
Abstract Waves in plasma play an essential role the energy transfer and plasma-heating processes. This article discusses situ observation of Alfvén ion cyclotron (AIC) waves their characteristics within interplanetary coronal mass ejection (ICME) flux ropes. We analyzed 401 ICME ropes, observed by WIND spacecraft from 1995 to 2021 at 1 au. found only five ropes that show explicit presence AIC waves; two have normalized magnetic helicity σ m ≤ −0.5, remaining three ≥ 0.5 polarization. The...
Interplanetary Coronal Mass Ejections (ICMEs) are prominent drivers of space weather disturbances and mainly lead to intense or extreme geomagnetic storms. The reported studies suggested that the planar ICME sheath magnetic clouds (MCs) cause Here, we investigated severe two-step storm ($Dst \sim -187$ nT) 25$^{th}$ solar cycle. Our analysis demonstrates flattened (pancaked) structures, i.e., quasi-planar structures (PMS). study corroborates our earlier finding less adiabatic expansion in...
The dynamic evolution of coronal mass ejection (CME) in interplanetary space generates highly turbulent, compressed, and heated shock-sheath. This region furnishes a unique environment to study the turbulent fluctuations at small scales serve an opportunity for unfolding physical mechanisms by which turbulence is dissipated plasma heated. How does magnetized control energy transport process astrophysical plasmas attractive challenging open problem 21st century. For this, literature discusses...
The Alfvén wave (AW) is the most common fluctuation present within emitted solar wind from Sun. Moreover, interaction between interplanetary coronal mass ejection (ICME) and high-speed stream (HSS) has been observed on several occasions. However, can such generate an AW? What will be nature of AW in a scenario remains open question. To answer it, we have investigated ICME-HSS event 21st October 1999 at 1 AU by Wind spacecraft. We used Walén test to identify estimated Elsasser variables find...
Alfvén waves (AWs) are inevitable in space and astrophysical plasma. Their crucial role various physical processes, occurring plasma, has triggered intense research solar-terrestrial physics. Simulation studies have proposed the generation of AWs along surface a cylindrical flux rope, referred to as Surface (SAWs); however observational verification this distinct wave been elusive date. We report first \textit{in-situ} observation SAWs an interplanetary coronal mass ejection rope. apply...
The Forbush decrease (FD) and Geomagnetic storm (GS) are the two distinct space weather events having common causing agents like interplanetary coronal mass ejection (ICME) or corotating interacting region (CIR). Generally, an ICME causes high amplitude FDs extreme GSs. However, interlinks between GS strong poorly studied. Here, we demonstrate five induced storms their effects on respective FD profiles. We observed sudden commencement of coincides with onset. Interestingly, also noted a...