Sujan Prasad Gautam

Sujan Prasad Gautam
University of Alabama in Huntsville | UAH · Department of Space Scence & CSPAR

Ph.D. Student

About

38
Publications
70,556
Reads
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144
Citations
Introduction
I am a PhD candidate in Space Science at the University of Alabama in Huntsville. My research focuses on solar wind turbulence, particularly the nature of small-scale turbulence fluctuations in the vicinity of interplanetary shocks. I have contributed to several peer-reviewed publications and regularly present my findings at international conferences.
Additional affiliations
June 2019 - August 2019
Leiden Observatory
Position
  • Summer Research Student
Education
January 2022 - May 2024
University of Alabama in Huntsville
Field of study
  • Space Science
May 2017 - February 2021
Tribhuvan University
Field of study
  • Physics and Astrophysics
October 2012 - June 2016
Tribhuvan University
Field of study
  • Physics and Statistics

Publications

Publications (38)
Article
Full-text available
We analyzed the behavior of Cosmic-Ray (CR) intensity during five geomagnetic events over 9-day periods of varying disturbance, using ground-based CR measurements from the Bartol Research Institute neutron-monitor program that occurred on 25th October – 2nd November 2003, 23rd – 31st July 2004, 13th – 21st May 2005, 13th – 21st Mar 2015, and 19th –...
Article
Full-text available
In this paper, we investigate the performance of the NeQuick 2 (NeQ-2) model with respect to Ciraolo’s and Gopi’s derived ionospheric vertical Total Electron Content (vTEC) during the years 2014 and 2015. GPS observables derived from dual-frequency receivers over western Nepal (Simikot, Bhimchula, and Nepalganj) are processed to obtain the experime...
Article
This study explores temporal variations in seismic data, interplanetary parameters, and geomagnetic indices during the 2015 Coquimbo earthquake. We employ wavelet transform techniques to investigate potential coupling mechanisms between the lithosphere, atmosphere, and ionosphere (LAI), even during geomagnetically disturbed periods. Our analysis is...
Article
Full-text available
We study the solar cycle dependence of various turbulence cascade rates based on the methodology developed by Adhikari et al. that utilizes Kolmogorov phenomenology. This approach is extended to derive the heating rates for an Iroshnikov–Kriachnan (IK) phenomenology. The observed turbulence cascade rates corresponding to the total turbulence energy...
Article
Full-text available
A multispecies energetic particle intensity enhancement event at 1 au is analyzed. We identify this event as a corotating interaction region (CIR) structure that includes a stream interface (SI), a forward-reverse shock pair, and an embedded heliospheric current sheet (HCS). The distinct feature of this CIR event is that (1) the high-energy (>1 MeV...
Article
Full-text available
A total solar eclipse occurred on April 8, 2024, across the United States, with obscuration rates ranging from 20–100% at different locations. We study the ionospheric Total Electron Content (TEC) response to the eclipse using data from 51 ground-based GPS stations. We find a significant depletion in TEC of up to 65%, with larger depletion rates oc...
Article
Full-text available
This study investigated the relationship between the cosmic ray intensity (CRI) and the horizontal component of Earth's magnetic field (dH) during two intense geomagnetic storms that occurred on September 8, 2017, and August 26, 2018, and a moderate storm on February 18, 2020 over three stations: IRKT, YKTK, and HRMS. The findings of this study ind...
Article
Full-text available
This study investigates the ionospheric response to a geomagnetic storm triggered by a Coronal Mass Ejection (CME) during 6–9 September 2017, across GPS stations located in diverse geographical regions. We analyze the changes in the magnetic field component (Δ𝐻), the Prompt Penetration Electric Fields (PPEF), and the Total Electron Content (TEC). W...
Article
Full-text available
This work studies variations of ionospheric total electron content (TEC) during four distinct solar eclipse events over the Ethiopia region. Dual‐frequency global positioning system (GPS) data obtained from UNAVCO over Addis Ababa (9.036°N, 38.76°E) and Bahir Dar (11.6°N, 37.34°E) stations are used to examine the ionospheric variability during two...
Article
Full-text available
This work investigates the relationship between cosmic ray intensity (CRI) and key interplanetary and geomagnetic parameters during both disturbed (November 1-6, 2021) and quiet (November 7-12, 2021) periods. Four neutron monitor stations, namely BKSN, DOMC, JUNG, and MXCO, are employed to analyze the behavior of CRI in response to variations in so...
Article
Full-text available
This work investigates the effects of two intense geomagnetic storms on Total Electron Content (TEC) in the ionosphere at high latitude stations situated in different hemispheres. Using ground-based GNSS receivers and the IRI-2016 model, the study analyzes TEC data collected from Kerguelen station (55.78°S, 133.44°E) in the southern hemisphere and...
Article
Full-text available
Geomagnetic storms have very profound effects on the Total Electron Content (TEC) of the ionosphere. In order to investigate the equatorial and low-latitude ionospheric response to the geomagnetic storms of varying intensities, a detailed study of vertical TEC (VTEC) variations resulting from Global Positioning System (GPS) data acquired at four GP...
Article
Full-text available
In this study, wavelet analysis and traditional cross-correlation analysis (TCA) have been employed to explore the temporal characteristics of the Air Quality Index (AQI) (PM2.5) and its relationships with meteorological factors, air temperature, and rainfall in the capital city of Nepal, Kathmandu, during 2017 - 2020. The temporal variation of mon...
Article
Full-text available
Total electron content and electron density are the fundamental parameters that determine the main properties of the ionosphere. We have observed variation of Global Positioning System (GPS) derived Vertical Total Electron Content (VTEC) on three different geomagnetic events. The observed VTEC data is recorded from four GPS stations at different lo...
Article
Full-text available
We analyzed the relativistic electron fluxes (E > 2 MeV) during five different geomagnetic storms: moderate, intense, super-intense, ICME HILDCAA (High-Intensity Long Duration Continuous Aurora Activity), non-storm HILDCAA and a geo-magnetically quiet period. We have opted for continuous wavelet (CWT) analysis techniques to comprehend the periodici...
Article
Full-text available
As the study of ionospheric behavior during various solar activities is an important task, various studies of ionospheric changes during eclipse events have been widely performed in the different regions of the globe. This paper investigates the ionospheric responses to the solar eclipse on 22 July 2009 over Nepal using the total electron content (...
Article
Full-text available
The Parker Solar Probe (PSP) satellite was launched by NASA in 2018 to study the Sun's environment from a closer distance than any spacecraft has ever reached before, revealing new insights about our star. Based on past few encounters data, numerous crucial findings have been already discovered; the data collected by the probe during each encounter...
Article
Full-text available
We studied the dust properties of two cavity structures (namely FIC21+54 and FIC16-56) nearby Asymptotic Giant Branch (AGB) stars using Infrared Astronomical Satellite (IRAS) maps. Dust color temperature, Planck function, dust mass, and visual extinction with their distribution within the region of interest were examined. The temperature of dust wa...
Preprint
Researchers have studied the interplanetary magnetic field (IMF) and solar-wind (SW) parameters that influence the development of geomagnetic storms for more than a decade. This study utilised newly developed tools for investigating the association between solar and interplanetary plasma parameters along with geomagnetic (GM) indices during two dif...
Article
Full-text available
This work presents the study of the quietest time variation in relativistic electrons, auroral precipitation, ring current, and joule heating during 1999, 2000, and 2004. Geostationary Operational Environmental Satellite (GOES) data on relativistic electrons with energies above 0.6 MeV, 2 MeV, and 4 MeV were analyzed. The time-series analysis of th...
Preprint
Full-text available
The outbreak of the COVID-19 pandemic and the subsequent global economic shutdown provided an opportunity to conduct a real-time experiment assessing the influence of global emission reductions in the Aerosol Optical Depth (AOD) level, an indicator of air pollution over Nepal. Nepal's government imposed a lockdown on the country for approximately t...
Article
Full-text available
In this paper, we have studied solar wind parameters, interplanetary magnetic field (B), solar wind speed (Vsw), solar wind density (Nsw), solar wind temperature (Tsw), and the south-north components of magnetic field Bz, By and Bx and geomagnetic index, SYM-H during the geomagnetic event of 27th-29th September 2017 and 25th-27th August 2018 using...
Article
Full-text available
In this study, we reviewed the maximum and minimum temperature trends of the Kathmandu valley over the period of 2011-2017. In addition, the average monthly temperature trends were studied annually for the same period, with the data made available from the Department of Hydrology and Meteorology (DHM) of Nepal. The annual temperature trended in the...
Article
Full-text available
In this paper, we have presented an analysis of emission lines from two dwarf galaxies. We analyzed the strongest emission lines of wavelength ranging from 4100 Å to 6700 Å. Among these emission lines, Hα and OIII have the highest intensities with 113.09×10-17 erg/s/cm 2 /Å and 142.12×10-17 erg/s/cm 2 /Å in the galaxies SDSSJ222726.64+120539.8 and...
Preprint
Full-text available
We analyzed the behavior of Cosmic Ray (CR) intensity during five geomagnetic events over 9-day periods of varying disturbance, using ground-based CR measurements from the Bartol Research Institute neutron monitor program that occurred on A nine-day time frame choice gives us a reasonable time interval for data analysis before, during, and after th...
Article
Full-text available
We performed a spectroscopic analysis of two low redshift dwarf galaxies, SDSSJ080947.50+213717.2, and SDSSJ151839.94+220514.4 selected from a catalogue of Paudel et al. 2018. The strong emission lines of the SDSS spectra of both galaxies were studied and the elements responsible were identified for those characteristic lines. The line ratio betwee...
Article
Full-text available
On 26th December 2019, during morning hours, an annular solar eclipse having a magnitude of 0.96 with a 118 km wide antumbra occurred and lasted for 3 minutes and 40 seconds at the point of maximum eclipse. The partial eclipse was visible in most of Asia, parts of North/East Africa, and North/West Australia. In the context of Nepal, only the partia...
Article
Full-text available
The dual‐frequency global positioning system (GPS) data acquired from the UNAVCO over different places of Nepal were processed to examine the eclipse‐triggered consequences on total electron content (TEC) in response to the annular solar eclipse of 15th January 2010 and 21st June 2020. These occasions were exceptional since they occurred during sol...
Article
Full-text available
The Geostationary Operational Environmental Satellites (GOES) have been monitoring the Earth's radiation environment and is providing the electron flux data (of energy >0.8 MeV, >2 MeV, and >4 MeV) by means of a connected sensor subsystem. Relativistic electron flux is one of the components of the radiation belt which not only affects the electrica...
Article
Full-text available
The physical properties such as dust color temperature, dust mass, visual extinction, and Planck function with their distribution in the core region of two far-infrared cavities, namely FIC16-37 (size ~ 4.79 pc x 3.06 pc) located at R.A. (J2000): 16h 33m 57.25s & Dec. (J2000): -37d 47m 04.3s, and FIC12-58 (size ~ 22.54 pc x 14.84 pc) located at R.A...
Article
Full-text available
Measurement of outdoor natural background radiation doses at different locations of Pokhara city, Nepal was carried out using GCA-07W, Nuclear Regulatory Commission (NRC) certified Geiger Muller (GM) detector. From the measurements, the least value of background radiation dose rate was found to be 0.26 ± 0.08 μSv/hr for Mahendra Cave area, and the...
Article
We performed a study of dust color temperature and Planck function distribution of a far-infrared (FIR) planetary nebula structure (90 μm and 140 μm) under the AKARI (infrared astronomy satellite developed by Japan Aerospace Exploration Agency) survey. An interesting nebular structure (major diameter ~ 1.57 pc and minor diameter ~ 1.38 pc) is found...
Article
Full-text available
Air pollution is a challenging problem globally and the entire globe is dealing with the lhazard caused by it. It harms different environmental factors that directly or indirectly cause health problems. Due to rapid urbanization and various infrastructure development projects, the level of air pollution of Kathmandu city is increasing day by day. W...
Poster
Full-text available
The ionosphere is a dynamic layer of the upper part of the atmosphere, which generally changes according to radiation emitted by the sun, the movement of the earth around the sun, and sunspot activity. Variations can generally be categorized as regular or irregular variations. Both types of variation have a huge effect on radio wave propagation. In...

Questions

Questions (52)
Question
Dear researchers,
I am working on a project related to solar wind. I want to download a 1-minute resolution data from a BepiColombo spacecraft. However, I am struggling with that. Do you know any websites to download the data? OR, If you could help me to provide a BepiColombo data just for few days, it would be very helpful. I am expecting a valuable comments from a wonderful personalities.
Many thanks.
Question
For the magnetic reconnection, frozen-in condition should be broken down. I was wondering If this condition can not be satisfied, what would happen when the anti-parallel magnetic field are pushed to each other?
Question
If the magnetic mirror is asymmetric, is the minimum injection angle in symmetric mirror to be able to reflect particles in the mirror? Why?
Question
I was wondering about the terms "homogeneous" and "unmagnetized" plasma. Thank you.
Question
From the correlation analysis, in the past, it is estimated that Vsw has quite a good correlation with IMF-Bz during the geomagnetic storm events; however, for some intense events, quite less correlation between Vsw and IMF-Bz was also observed, what could be the possible factors behind this?
Question
We performed a correlation analysis of solar wind speed (Vsw) with z-component of interplanetary magnetic field (Bz) during geomagnetic storm events with different strengths. We found varying results: a bit larger correlation coefficient for some events, but also a moderate association during some events. What sort of results can we expect?
Question
For the physics graduate program in the USA, I used to access brief information about the universities from the website: https://gradschoolshopper.com/?rec=241. However, they have limited their services and request us for the premium now. Please let me know if there are some useful websites that contain detailed information about all the universities for graduate programs in the USA.
Question
We have looked AOD data from aeronet site. However, we found a large amount of data is missing for different stations of Nepal. Do you aware of some satellite data for AOD over the regions of Kathmandu? If yes, please let us know the website for data download. Thank you.
Question
We have prepared a short article related to space weather. We think it is suitable for Q3-Q4 ranked Scopus indexed journal. Although there are numerous journals related to the field of space science, we found a very long article processing duration (about 8 months to 12,14 months). Thus, we couldn't select the appropriate one. We would be happy to know some fast processing, free, SCOPUS ranked journals (it is okay if they are lower ranked). Thank you.
Question
SOP is one of the important document to enhance our chances for admission in the universities. What is a actual length of a SOP? How the best SOP can be prepared? Please kindly suggest some samples for SOP prepration.

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