PhD in IAGA #6

IAGA has a lot of different scientists working on various topics. In this series of blogs, we introduce some topics that were or are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Dr. Anita Devi completed her postgrad from the Department of Geophysics, Kurukshetra University, India after which she worked for two years as a Geophysicist in TVIPL. She did her Ph.D. from Indian Institute of Technology, Roorkee in 2019. For a brief period of 3 months, she also worked as a Post-Doctoral fellow (SERB-NPDF) at Wadia Institute of Himalayan Geology, India. During her doctoral research, she worked on various electrical and electromagnetic prospecting methods to deciphered resistivity structures. She is currently working as a Scientist at CSIR-NGRI, in magnetotelluric group. 

Her Ph.D. research was focused on 3D (3-Dimensional) individual and joint inversion of magnetotelluric (MT), Radio magnetotelluric and Electrical resistivity tomography (ERT) data. She presented the first 3D resistivity model for Garhwal Himalayan region around Roorkee-Gangotri and Chamoli region. She has worked on all the aspects of Magnetotelluric (acquisition, processing, 3D modelling and inversion). She is interested in delineating the 3D resistivity subsurface structures for exploration and tectonic studies. Her earlier work focuses on the geodynamic studies of Himalayan region. Currently she is working on 3D MT studies of both the Central Indian Tectonic Zone and the Himalaya region. She has published research papers in reputed national and international journals like Journal of Applied Geophysics and Near Surface Geophysics and participated in several International workshops (EMIW, IAGA-IASPEI).

Depth slices of the inverted 3D electrical model of Roorkee-Gangotri profile from Devi et al. 2019 with the letters marking the major resistivity features.

PhD in IAGA #5

IAGA has a lot of different scientists working on various topics. In this series of blogs, we will introduce some topics that are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Sarasija Sanaka, is a PhD student working at the Institute of Geophysics Polish Academy of Science, Poland. Her supervisor is Dr. hab. Anne Neska. Sarasija says:

My research is about source effects in Magnetotellurics. Source effects are the inappropriate source signals which lead to distortion in the results, which further leads to misinterpretation of the subsurface electrical structure. My task is to identify and understand the origin of such problematic signals. Such signals are dominant in the high to mid-latitude regions. To recognize source effects, we have considered long-term magnetotelluric data, because they reveal temporal changes which cannot be explained by subsurface conductivity changes.

The above figures represent time-dependent transfer functions at 4000s for Grabnik (GRB) and Suwałki (SUV) stations in Poland.

PhD in IAGA #4

IAGA has a lot of different scientists working on various topics. In this series of blogs, we will introduce some topics that are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Hannah Rogers, a PhD candidate at the University of Edinburgh, says:

In my research, I'm interested in separating the Earth's magnetic field into local regions to better comprehend the core-mantle interactions. Most core flow and magnetic field models are described by spherical harmonics. However, they are not suitable for separation into different regions due to leakage. I instead use spherical Slepian functions to spatially and spectrally separate bandlimited potential fields. Long-lived features of the magnetic field have been guessed to be linked to Large Low Velocity Provinces (LLVPs). They are low seismic velocity regions in the lowermost mantle. My aim is to use the Slepian functions to investigate how LLVPs affect core surface flows over time.

The outer core and lower mantle interactions. The arrows represent the magnetic field lines. Credits : Kay Lancaster

PhD in IAGA #3

IAGA has a lot of different scientists working on various topics. In this series of blogs, we will introduce some topics that are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Samuel Fielding, a PhD candidate at the University of Edinburgh, says:

My research topic is looking at the current forecasting capabilities within the field of space weather, and trying to improve them and find new avenues of research within the field using machine learning. With the large amounts of data being collected on space weather from the many satellites currently in orbit around the Earth or at the L1 Lagrange point, there is a lot of data to train machine learning algorithms on, and the Earth-Sun system is currently not well modelled by current physical models because of the complexity of interactions within the system. This means that the field is a perfect place to explore machine learning models, and it is a very active field with a lot of research on optimising current prediction models. Can these models be optimised further, and looking forwards, is machine learning the right way for us to predict space weather events?

 

False-colour image of a solar eclipse from 21 August 2017. Copyright Miroslay Druckmuller. As published in SciTechDaily, 21 June 2021 and Habbal et al. 2021.

PhD in IAGA #2

IAGA has a lot of different scientists working on various topics. In this series of blogs, we will introduce some topics that are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Shivangi Sharan is a PhD candidate working in the Laboratory of Planetology and Geosciences at Nantes University, France. She says:

My research entails studying the magnetic field of planets, typically Mars and Jupiter, and deciphering information about its interior structure from them. There are internal and external sources of magnetic fields around a planet which can be modeled using Spherical Harmonics. These models then go on to provide us some details about the static and transient fields as well as about the change in field over time.

Radial component of the internal magnetic fields at the surface of the planets. Credit : From a study report for the Keck Institute for Space Studies (KISS) (https://kiss.caltech.edu/final_reports/Magnetic_final_report.pdf) 

PhD in IAGA #1

IAGA has a lot of different scientists working on various topics. In this series of blogs, we will introduce some topics that are being worked on by PhD students. Hopefully this will give a better picture of the work being done in the field and encourage more early career researchers.

Paweł Jujeczko is a PhD candidate working in the Space Research Centre at the Polish Academy of Sciences. He says:

My research topic concerns the physics of Transient Luminous Events (TLEs). For those not familiar with that abbreviation, TLEs are some various phenomena that occur over very powerful thunderclouds (~10 to 100 km above the ground). In my research I model the behaviour of a TLE called "sprite" with a multi-processor code which works within the kinetic plasma theory. I try to model an instability that is possibly present in a plasma of TLE conditions or in simpler words, I try to tell why sprites look like these on the picture here.

Credit : https://apod.nasa.gov/apod/ap191008.html