Education:
Aug 2013: PhD, Department of Physics, Indian Institute of Science (IISc), Bangalore, India. 
Thesis title: Theoretical study of the solar magnetic cycle and its irregularities. Advisor: Prof. Arnab Rai Choudhuri

Jul 2009: M.S. (Physics), IISc, Bangalore, India.

Aug 2006: B.Sc. (with Physics Honours and Mathematics and Chemistry as subsidiary subject), Bankura Christian College, Burdwan University, Bankura, India.

Employment:
May 2018 – Present: Assistant Professor, Indian Institute of Technology, Varanasi (IIT-BHU), India.
Jan – Apr 2018: Chandrasekhar Postdoctoral fellow, Indian Institute of Astrophysics, Bangalore, India.
Jan 2016 – Jan 2018: Jack Eddy Postdoctoral fellow, High Altitude Observatory, National Center for Atmospheric Research (NCAR), Boulder, CO, USA.
Sep 2015 – Dec 2015​: Guest Scientist, Max Planck Institute for Solar System Research (MPS), Göttingen, Germany.
Sep 2013 – Aug 2015​: NORDITA Postdoctoral fellow, NORDITA Nordic Institute for Theoretical Physics, Stockholm,
Sweden.

Please find my full CV here.

Areas of research interest:
Astrophysics, specifically, magnetohydrodynamics (MHD) and its applications to the Sun and other stars; Dynamo theory and origin of magnetic fields in stars, planets and galaxies; Astrophysical fluids, turbulence, and convection; Large-scale flows such as differential rotation and meridional circulation in the solar convection zone, sunspot and solar cycle; Effect of solar cycle on the Earth’s global climate; and Nonlinear and chaotic behaviors of astrophysical objects.

Major research experience:
In my PhD thesis, I explored the origin and the evolution of Sun’s large-scale magnetic field, the solar cycle and particularly their irregular features such as the Waldmeier effect and grand minima using two-dimensional Babcock-Leighton/flux transport dynamo models. Later I worked on simulations of MHD turbulence and small- and large-scale dynamos in Cartesian geometry as well as the global spherical geometry of solar convection zone with the Pencil Code. Currently, I am working on a state-of-the-art 3D Surface Transport and Babcock-LEighton (STABLE) dynamo model for the solar cycle and planning to extend it to other stars, and the solar convection.

My publications can be found on

the Google Scholar page
and 
SAO/NASA Astrophysics Data System (ADS)

Manuscript Submitted/Accepted:

52. S. Wavhal, P. Kumar, D. Mishra, & B. B. Karak: Analyses of features of magnetic cycles at different amounts of dynamo supercriticality: Solar dynamo is about two times critical, Sol. Phys., Submitted (2024).

Manuscript Published:
International Journals

51. V. Vashishth & B. B. Karak: The role of meridional flow in the generation of solar/stellar magnetic fields and cycles, ApJ, 974, 6 (2024)  (Impact Factor: 4.9).

50. A. Sreedevi, B. K. Jha, B. B. Karak & D. Banerjee: Analysis of BMR tilt from AutoTAB catalog: Hinting towards the thin flux tube model?, ApJ, 966, 112 (2024)  (Impact Factor: 4.9).

49. A. Ghosh, P. Kumar, A. Prasad, & B. B. Karak: Characterizing the solar cycle variability using nonlinear time series analysis at different amounts of dynamo supercriticality: Solar dynamo is not highly supercritical,  Astronomical Journal, 167, 209 (2024)  (Impact Factor: 5.3).

48. P. Kumar, B. B. Karak & A. Sreedevi: Variabilities in the polar field and solar cycle due to irregular properties of Bipolar Magnetic Regions, Under review in MNRAS, 530, 2895-2905 (2024)  (Impact Factor: 5.36).

47. A. Biswas, B.B. Karak, & P. Kumar, Exploring the reliability of polar field rise rate as a precursor for an early prediction of solar cycle, MNRAS, 526, 3, 3994–4003 (2023). https://ui.adsabs.harvard.edu/abs/2023MNRAS.tmp.2836B/abstract (Impact Factor: 5.36)

46. A. Sreedevi, B. Jha, B.B. Karak, & D. Banerjee, AutoTAB: Automatic Tracking Algorithm for Bipolar Magnetic Regions, APJS 268, 2, 58 (2023). https://ui.adsabs.harvard.edu/abs/2023ApJS..268...58S/abstract (Impact Factor: 8.7)

45. E.M. Golubeva, A. Biswas, A.I. Khlystova, P. Kumar & B.B. Karak, Probing the variations in the timing of the Sun's polar magnetic field reversals through observations and surface flux transport simulations MNRAS, 525, 2, 1758-1768 (2023) (Impact Factor: 5.36).

44. B.B. Karak, Models for the long-term variations of solar activity;  Living Reviews in Solar Physics (invited review; Impact Factor: 20.9) 21, 3 (2023).

43. V. Vashishth, B. B. Karak, & L. Kitchatinov:
      Dynamo modelling for cycle variability and occurrence of grand minima in Sun-like stars: rotation rate dependence, MNRAS, 522, 2, 2601-2610 (2023) (Impact Factor 5.36): https://ui.adsabs.harvard.edu/abs/2023arXiv230405819V/abstract

42. A. Biswas, A., B. B. Karak, Ilya Usoskin & Eckhard Weisshaa:
      Long-Term Modulation of Solar Cycles, Space Science Review (SSR), 219, 19 (2023) (Impact Factor 8.017): https://ui.adsabs.harvard.edu/abs/2023SSRv..219...19B/abstract

41. A. Biswas, A., B. B. Karak R., & Cameron:
      Toroidal flux loss due to flux emergence explains why solar cycles rise differently but decay in a similar way, Physical Review Letters (PRL), 129, 241102 (2022) (Impact Factor 9.185).

40. P. Kumar, A. Biswas, A. & B. B. Karak:
      Physical link of the polar field build-up with the Waldmeier effect broadens the scope of early solar cycle prediction: Cycle 25 is likely to be stronger than Cycle 24, MNRAS Letters 513, L 112-116 (2022) (Impact Factor 5.29).

39. A. V. Mordvinov, B. B. Karak, D. Banerjee, E. M. Golubeva, A. L. Khlystova, A. V. Zhukova, & P. Kumar: 
      Evolution of the Sun’s magnetic fields and their reversals in Cycles 21–24: A closer look, MNRAS, 510, 1331 (2022); arxiv.org/abs/2111.15585​ (Impact Factor: 5.36)

38. R. Das, Ghosh, A. & B. B. Karak:
      Is the hemispheric asymmetry of sunspot cycle caused by an irregular process with long-term memory?, MNRAS, 551, 472  (2022)​ ; arxiv.org/abs/2111.06332(Impact Factor: 5.36)

37. P. Kumar, B. B. Karak & V. Vashishth:
      Super-criticality of dynamo limits the memory of polar field to one cycle, The Astrophysical Journal, 913, 65 (2021) ; arxiv:2103.11754 (Impact Factor: 5.75).

36. V. Vashishth, B. B. Karak, & L. Kitchatinov:
      Subcritical dynamo and hysteresis in a Babcock-Leighton type kinematic dynamo model, Research in Astronomy and Astrophysics 21, 266 (2021) (Impact Factor: 1.25).

35. P. Kumar, Nagy, M., L. Alexandre, B. B. Karak & K. Petrovay:
      The polar precursor method for solar cycle prediction: comparison of predictors and their temporal range, The Astrophysical Journal 909, 87; arXiv:2101.05013 (2021) (Impact Factor: 5.75).

34. Oliveira, D., Rempel, E., Chertovskih, R., Karak, B. B.: 
      Chaotic transients and hysteresis in an $\alpha^2$ dynamo model, Journal of Physics: Complexity (2021), arixv:2012.02064

33. A. V. Mordvinov, B. B. Karak, D. Banerjee, S. Chatterjee, E. M. Golubeva, A. L. Khlystova:
      Long-term evolution of the sun's magnetic field during cycles 15-19 based on the proxies from Kodaikanal Solar Observatory, Astrophysical Journal Letters, 902, L15 (2020) (Impact Factor: 8.2).

32. B. B. Karak: 
      Dynamo saturation through the latitudinal variation of bipolar magnetic regions in the sun, accepted in Astrophysical Journal Letters 901, L35 (2020): arxiv: 2009.06969 (Impact Factor: 8.2)

31. Z. Yang, C. Bethge, H. Tian, S. Tomczyk, R. Morton, G. Zanna, SW. McIntosh, B. B. Karak, S. Gibson, T. Samanta, J. He, Y. Chen, L. Wang:
      Global maps of the magnetic field in the solar corona​, Science 369, 6504 (2020). (Impact Factor: 63.71)

30. Jha, B. Karak, B. B., Mandal, S., & Banerjee, D.:
     Magnetic field dependence of bipolar magnetic region tilts on the Sun: Indication of tilt quenching​, ApJL  889, p7 (2020); arxiv.org/abs/1912.13223 (Impact Factor: 8.2)

29. Karak, B. B., Tomar, A.,& Vashishth, V.:
      Stellar Dynamos with Solar and Anti-solar Differential Rotations: Implications to Magnetic Cycles of Slowly Rotating Stars, (2019), MNRAS, 491, 3155, arXiv:1910.11893​ (Impact Factor: 5.36)

28. Garg, S., Karak, B. B., Ricky Egeland, Soon, W.  & Baliunas, S:
      Waldmeier Effect in Stellar Cycles, The Astrophysical Journal, 886, 132; arXiv: 1909.12148, (2019) (Impact Factor: 5.75)

27. Hazra, G., Jiang, J. Karak, B. B., & Kitchatinov, L. L.:
      Exploring cycle period and parity of stellar magnetic activity with dynamo modeling, (2019), The Astrophysical Journal 884, 35, arxiv.org/abs/1909.01286 (Impact Factor: 5.75)

26. Karak, B. B., Mandal, S., & Banerjee, D.:
      Double-peaks of the solar cycle: An explanation from a dynamo model, arXiv:1808.03922 (2018), The Astrophysical Journal, 866, 17. (Impact Factor: 5.75)

25. Srivastava, A. K.; McIntosh, S. W.; Arge, N.; Banerjee, D.; Cliver, E.; Dikpati, M.; Dwivedi, B. N.; Guhathakurta, M.; Karak, B. B. et al. 
      The Extended Solar Cycle: Muddying the Waters of Solar/Stellar Dynamo Modeling Or Providing Crucial Observational Constraints? Frontiers in Astronomy and Space Sciences 5, 38, arXiv:1807.07601 (2018).

24. Karak, B. B. & Miesch, M.:
      Recovery from Maunder-like Grand Minima in a Babcock--Leighton Solar Dynamo Model, Astrophysical Journal Letters, 860, L26 (2018). (Impact Factor: 8.19)

23. Karak, B. B., Miesch, M. & Bekki, Y.:
      Effects of Prandtl number on the stellar convection and differential rotation, Physics of Fluids, 30, 046602, arXiv:1801.00560 (2018) (Impact Factor: 4.98).

22. Mandal, S., Karak, B. B. & Banerjee, D.: Latitude distribution of sunspots: analysis using sunspot data and a dynamo model, The Astrophysical Journal, 851, 70, arXiv:1711.00222 (2017) (Impact Factor: 5.75).

21. Karak, B. B. & Miesch, M.: Solar cycle variability induced by tilt angle scatter in a Babcock–Leighton solar dynamo model, The Astrophysical Journal, 847, 69, arXiv:1706.08933 (2017) (Impact Factor: 5.75).

20. Karak, B. B. & Cameron, R.: Babcock-Leighton solar dynamo: the role of downward pumping and the equatorward propagation of activity, The Astrophysical Journal, 832, 94, arXiv:1605.06224 (2016) (Impact Factor: 5.75).

19. Karak, B. B. & Brandenburg, A.: Is the small-scale magnetic field correlated with the dynamo cycle? The Astrophysical Journal, 816, 28, arXiv:1505.06632 (2016) (Impact Factor: 5.75).

18. Käpylä, M. J., Käpylä, P., Olspert, N., Brandenburg, A. Warnecke, J., Karak, B. B. & Pelt, J.: Multiple dynamo modes as a mechanism for long-term solar activity variations, Astronomy and Astrophysics, 589, 56, arXiv:1507.05417 (2016) (Impact Factor: 5.64).

17. Karak, B. B., Kitchatinov, L. L. & Brandenburg, A.: Hysteresis between distinct modes of turbulent dynamos, The Astrophysical Journal, 803, 95, arXiv:1411.0485 (2015) (Impact Factor: 5.75).

16. Hazra, G., Karak, B. B., Banerjee, D. & Choudhuri, A. R.: Correlation between Decay Rate and Amplitude of Solar Cycles as Revealed from Observations and Dynamo Theory, Solar Physics, 290, 1851, arXiv:1410.8641 (2015) (Impact Factor: 2.58).

15. Karak, B. B., Käpylä, P., Käpylä, M. J. Brandenburg, A., Olspert, N. & Pelt, J.: Magnetically controlled stellar differential rotation near the transition from solar to anti-solar profiles, Astronomy and Astrophysics, 576, 26, arXiv:1407.0984 (2015) (Impact Factor: 5.64).

14. Karak, B. B., Rheinhardt, M., Brandenburg, A., Käpylä, P. J. & Käpylä, M. J.: Quenching and anisotropy of hydromagnetic turbulent transport. The Astrophysical Journal, 795, 16, arXiv:1406.4521 (2014) (Impact Factor: 5.75).

13. Priyal, M., Banerjee, D., Karak, B. B., Munoz-Jaramillo, A., Ravindra, B., Choudhuri, A. R. & Singh, J.: Polar Network Index as a magnetic proxy for the solar cycle studies. The Astrophysical Journal Letters, 793, L4, arXiv:1407.4944 (2014). (Impact Factor: 8.19)

12. Karak, B. B., Kitchatinov, L. L. & Choudhuri, A. R.: A Dynamo Model of Magnetic Activity in Solar-like Stars with Different Rotational Velocities. The Astrophysical Journal, 791, 59, arXiv:1402.1874 (2014) (Impact Factor: 5.75).

11. Hazra, G., Karak, B. B. & Choudhuri, A. R.: Is a Deep One-cell Meridional Circulation Essential for the Flux Transport Solar Dynamo? The Astrophysical Journal, 782, 93, arXiv:1309.2838 (2014) (Impact Factor: 5.75).

10. Karak, B. B. & Choudhuri, A. R.: Studies of grand minima in sunspot cycles by using a flux transport solar dynamo model. Research in Astronomy and Astrophysics, 13, 1339, arXiv:1306.5438 (2013) (Impact Factor: 1.25).

9. Karak, B. B. & Petrovay, K.: On the compatibility of a flux transport dynamo with a fast tachocline scenario. Solar Physics, 282, 321, arXiv:1209.0319 (2013) (Impact Factor: 2.58).

8. Karak, B. B. & Nandy, D.: Turbulent Pumping of Magnetic Flux Reduces Solar Cycle Memory and thus Impacts Predictability of the Sun’s Activity. The Astrophysical Journal Letters, 761,
L13, arXiv:1206.2106 (Impact Factor: 8.19).

7. Choudhuri A. R. & Karak, B. B.: The origin of grand minima in the sunspot cycle. Physical Review Letters, 109, 171103, arXiv:1208.3947 (2012) (Impact Factor: 8.39).

6. Karak, B. B. & Choudhuri, A. R.: Quenching of Meridional Circulation in Flux Transport Dynamo Models. Solar Physics, 278, 137, arXiv:1111.1540 (2012) (Impact Factor: 2.58).

5. Karak, B. B. & Choudhuri, A. R.: The Waldmeier effect and the flux transport solar dynamo. Monthly Notices of the Royal Astronomical Society, 410, 1503, arXiv:1008.0824 (2010) (Impact Factor: 5.36).

4. Karak, B. B.: Importance of Meridional Circulation in Flux Transport Dynamo: Possibility of Maunder-like Grand Minimum. The Astrophysical Journal, 724, 1021, arXiv:1009.2479 (2010) (Impact Factor: 5.75). 

3. Karak, B. B., Dutta, J. & Mukhopadhyay, B.: Search for Chaos in Neutron Star Systems: Is Cyg X-3 a Black Hole?. The Astrophysical Journal, 708, 862, arXiv:0911.1701 (2010) (Impact Factor: 5.75).

2. Choudhuri, A. R. & Karak, B. B.: A possible explanation of the Maunder minimum from a flux transport dynamo model. Research in Astronomy and Astrophysics (Letters), 9, 953, arXiv:0907.3106 (2009) (Impact Factor: 1.25).

Review:
1. Karak, B. B., Jiang, J., Miesch, M., Charbonneau, P. & Choudhuri, A. R.: Flux transport dynamos: from kinematics to dynamics. Space Science Review, 186, 561, [download]. [This is basically a proceedings review produced by combining the presentations of above authors at the ISSI Bern workshop.] (Impact Factor: 9.33)

National
1. Verma, M., Karak, B. B. & Kumar, R.: Dynamo in protostars. Pramana, 81, 1037, arXiv:1304.6808 (2013) (Impact Factor: 1.69).

Some of the selected awards I have received are listed here:
2024: AAPPS-DPP Young Researcher (U40) Award for 2024 from the Association of Asia-Pacific Physical Societies (AAPPS) Division of Plasma Physics (AAPPS-DPP).
2021: Humboldt Research Fellowship from the Alexander von Humboldt Foundation, Germany.
2019: INSA Young Scientist Medal (2019) from Indian National Science Academy.
2018: Chandrasekhar Postdoctoral Fellowship (equivalent to a reader position) from Indian Institute of Astrophysics, Bangalore.
2015: Asia-Pacific Solar Physics Meeting (APSPM) Best Paper Award, South Korea.
2015: Thomas Metcalf Lecturer and SPD Travel Award - American Astronomical Society (AAS) Solar Physics Division (SPD), USA.
2015 – 2017: Jack Eddy Postdoctoral Fellowship award from UCAR and NASA Living With a Star program, USA.​
2015 – 2017: Research Fellowship from Max Planck Institute for Solar System Research, Germany (declined).
2014 – 2015: Kumari L A Meera Memorial Medal for the best thesis in Theoretical Physics, IISc, Bangalore.
2013: Justice Oak best thesis award from Astronomical Society of India (ASI).
2013 – 2015: NORDITA Fellowship from NORDITA, Nordic Institute for Theoretical Physics, Sweden.
2013 – 2016: Postdoctoral fellowship in Kiepenheuer Institute for Solar Physics, Germany (declined).
2008 – 2013: Research Fellowship awarded (twice) by the Council of Scientific and Industrial Research, Govt. of India.
2003: National Merit Scholarship based on West Bengal Higher Secondary exams.

Sponsored Project:
Jan 2024 – Jan 2027: “Development of a 3D non-kinematic dynamo model for the solar and stellar cycles", under MATRICS/SERB, grant amount: 6.60 lakhs.
Feb 2020 – Feb 2023: “On understanding the solar activity and preparing for space weather prediction using a state-of-art dynamo model", under RESPOND program of ISRO, grant amount: 30.99 lakhs.
Nov 2019 – Nov 2021: “Multiple reversals of the Sun’s polar-fields and their physical causes", under DST-RFBR program of DST, grant amount: 10.45 lacks.
Nov 2018 – Nov 2023: “Exploring the origin and dynamics of magnetic cycles of low main sequence stars" under Ramanujan Fellowship from SERB, DST, grant amount: 38 lakhs.
Nov 2019 - Jul 2023: "What Determines The Dynamo Effectivity Of Solar Active Regions?" led by Prof. K. Petrovay, sponsor: by International Space Science Institute, Bern, Switzerland, grant amount: travel expense.  

PhD students:
Ongoing:
Rohan Mandrai (Jul 2024 -- present), IIT (BHU) JRF NET, institute TA-ship; Thesis title: TBD.
Rambahadur Gupta (Jan 2024 -- present), IIT (BHU) JRF NET, institute TA-ship; Thesis title: TBD.
Anu B Sreedevi (2021 Jan -- present), IIT (BHU) JRF through institute TA-ship. Project: Long-term study of different proxies of solar activity and their implications in dynamo modelling.
Vindya Vashishth (Aug 2019 -- present), IIT (BHU) JRF through DST-INSPIRE: Project: Stellar dynamos of sun-like stars.

Completed:
Akash Biswas (Aug 2020 -- Dec 2023, submitted thesis), IIT (BHU) JRF through ISRO/RESPOND project. Thesis title: Understanding the solar activity and exploring the scope of space weather prediction.
Pawan Kumar (Jan 2019 -- Jan 2024), IIT (BHU) JRF NET, institute TA-ship; Thesis title: Understanding and forecasting the solar cycle variability using the polar magnetic field.

Project students:
Exploratory Project: One BTech student in Engineering Physics
UG+MTech project: Wavhal Sanket Sanjay 5-Year IDD Physics (5-year in Engineering Physics)
MSc Project: Dipanwita Misra (2024)

External project students:
Jun 2021 -- present:  Ankit Kumar (through Indian Academy of Science IASc-INSA-NASI Summer Research Fellowship in 2021).
May 2021 -- present: Jayesh Pandey (through Indian Academy of Science IASc-INSA-NASI Summer Research Fellowship in 2021).
Jun 2021 -- present: Kishan Deka (Integrated BS-MS student from NISER, Bhubaneswar).

Previous students (incomplete list):
Feb 2021 -- 2023: Aparup Ghosh (KVPY fellow and from 5-year BS-MS program at IISER Kolkata).
Jun 2020 -- 2022: Ratul Das, an Integrated MS student from NISER, Bhubaneswar, worked on time series analysis of sunspot data. 
Aug 2022 -- May 2023: Om Shiv Tripathi (MSc Project at Dept. of Physics,  IIT BHU)
Aug 2021 -- May 2022: Lupamudra Sarmah & Payal Yadav (MSc Project at Dept. of Physics,  IIT BHU).
Jan 2020 -- May 2022: Gandhi Aarsh Amulkumar (5-year in Engineering Physics; UG + MTech projects)
Aug 2020 -- May 2021: Sandeep Dubey (MSc Project at Dept. of Physics,  IIT BHU).
Aug 2020 -- May 2021: Deepanshi Lath (MSc Project at Dept. of Physics,  IIT BHU).
MTech Project: Kalva Aravind (5-year in Engineering Physics, Dept of Physics, IIT (BHU)).
UG Project: Gandhi Aarsh Amulkumar (5-year in Engineering Physics)
Jan 2021 - May 2021: VRS Sharan: Exploratory project (IDD IIT (BHU))
Govindswaroop Vishad Rahangdale (5-Yr IDD Materials Sci., & Tech., IIT (BHU))
Feb 2018 – Dec 2019: Bibhuti Kumar Jha, PhD student from Indian Institute of Astrophysics; worked on magnetic field dependence of BMR tilt. The paper got published in ApJL.
Jan 2020 - May 2020: Ankit Kumar Raj: Exploratory project (IDD IIT (BHU))
Jan 2020 -- Apr 2020: External Student: Arun Sharma (BTech from IIT-BHU; currently at University of California, Riverside)
Jul 2019 -- Dec 2019: Satyam Kr. Upadhyay (MSc student from Central Univ of Jharkhand) 
Mar 2019 – May 2019: Aparna Tomar, MSc, Uni. Delhi, worked with me on Stellar dynamos with solar and anti-solar differential rotations; the paper has been published in MNRAS.
Dec 2018 – Jul 2019: Suyog Garg, BTech student from IIIT-DM, worked on Waldmeier Effect in Stellar Cycles. the paper has been published in ApJ. Currently at The University of Tokyo.
Sep 2016 – Dec 2017: Partially mentored a PhD student, Sudip Mandal at Indian Institute of Astrophysics, Bangalore on a project: Latitudinal Distribution of Sunspots: Lesson from Dynamo Theory.
Sep 2017 – Oct 2018: Partially mentored a MS student, Yuto Bekki, The University of Tokyo, on a project: Understanding the solar convection in global MHD simulations.
2016 – August 2016: Kirsten McMichael, a student under Research Experience for Undergraduates (REU) Program in Solar and Space Physics at the University of Colorado, USA; project: Calibrating Your Cosmic Compass: What Determines the Magnetic Field Strength at the Sun’s North and South Poles?
Jun – Jul 2016: Anna Parker, REU Program in Solar and Space Physics at the University of Colorado, USA; project: Seeing Spots: Using supercomputer models to ask why all solar cycles are not created equal.
Jul 2015: Alexandra Berg and Alfred Isaac, students from Rays for excellence, Research Academy for Young Scientists, Sweden; projects: Effect of diffusivity quenching in kinematic mean-field dynamo model and Determination of the equatorward propagation speed of sunspots.
Jun 2014 Partially guided Jakob Broman, Ottilia Andersson and Toomas Liiv, students from Rays for excellence, Research Academy for Young Scientists, Sweden; projects: Chaotic oscillator, and Energy budgets of charged particles moving in a time-varying magnetic field.
Mar – Aug 2013 Partially mentored a beginner PhD student, Gopal Hazra at IISc, Bangalore; projects: (i) Multi-cell meridional circulation and its effect on kinematic mean-field dynamo models, and (ii) Correlation between decay rate and amplitude of solar cycles as revealed from observations and dynamo theory.

2021: Even Semester:
PYM 412: Advanced Mathematical Methods (MSc)
PHY 307, Advanced Mathematical Methods (IDD)
PHY-211:  Solar and Space Plasma Physics (BTech)
PHY-412:  Physics of Sun and its Atmosphere (IDD)

2021: Odd Semester:
PHY-302: Relativistic Electrodynamics (BTech)
PHY-404: Classical Electrodynamics (MSc)
PHY-102: Introduction to Engineering Electromagnetics (BTech)

2021: Even Semester:
PHY-102: Introduction to Engineering Electromagnetics (BTech)
2020: Even Semester:
PHY-311: Introduction to Astronomy and Astrophysics (IDD)
PYM-412:  Advanced Mathematical Physics (MSc)

2020: Odd Semester:
PYM-521: Space and Solar Physics (MSc)
PHY-302: Relativistic Electrodynamics (BTech)
PHY-404: Classical Electrodynamics (MSc)
PHY-102: Introduction to Engineering Electromagnetics (BTech)

2019: Even Semester:
PHY-504: Advanced Mathematical and Computational Physics (MSc)
PHY-412:  Physics of Sun and its Atmosphere (BTech)
PHY-211:  Solar and Space Plasma Physics (BTech)

2019: Odd Semester:
PHY-102: Introduction to Engineering Electromagnetics (BTech)
PHY-302: Relativistic Electrodynamics (BTech)
PHY-404: Classical Electrodynamics (MSc)

2018: Odd Semester:
PHY-102: Introduction to Engineering Electromagnetics (BTech)
PHY-302:  Relativistic Electrodynamics (BTech)
EP-511:  Space Weather (MTech)

Recent News

• I have been awarded AAPPS-DPP Young Researcher (U40) Award for 2024 from Association of Asia-Pacific Physical Societies (AAPPS) Division of Plasma Physics (AAPPS-DPP) for the fundamental studies of the flux transport dynamo mechanism in the Sun and other stars to provide theoretical explanations for different aspects of the solar and stellar cycles.
   
• My student Vindya Vashishth received International Travel Support (ITS) for presenting her research paper at IAU General Assembly, Cape Town during 6-15 Aug 2024.
   
• We have got some hints of the popular theory behind the sunspot formation, the thin flux tube model (https://ui.adsabs.harvard.edu/.../2024ApJ...966.../abstract). Here is a science nugget of our work: http://hmi.stanford.edu/hminuggets/?p=4253
   
• My student Pawan Kumar received prestigious full support for presenting his research work at 4th Eddy Cross-Disciplinary Symposium. Sun, Earth, Planet, Space, Atmosphere in The Golden, Colorado, USA.
   
• My student Akash Biswas received prestigious travel award through SCOSTEP to work with Prof. Nat Gopalswamy at  NASA’s Goddard Space Flight Center.
   
• My all four students: Vindya Vashishth, Anu Sreedevi, Pawan Kumar and Akash Biswas received travel grants to resent their research work in IAU (International Astronomical Union) 365 workshop at Yerevan, Armenia.
   
• Paper published in Physical Review Letters (PRL) on "Toroidal flux loss due to flux emergence explains why solar cycles rise differently but decay in a similar way";    See the science nugget based on this work: http://hmi.stanford.edu/hminuggets/?p=4107
   
• Published review on Long-Term Modulation of Solar Cycles by Biswas, A., Karak, B. B., Usoskin, I., & Weisshaar, E.:, Space Science Reviews, 219, 3 arxiv.org/abs/2302.14845
   
• Invited review published in prestigious journal: Living Reviews in Solar Physics on Models for the long-term variations of solar activity
   
• Prediction of the solar cycle is challenging, however, essential as solar activity drives space weather, which sometimes has hazardous effects on our space-based society. Several predictions for the amplitude of the ongoing Solar Cycle 25 have been made but it was still not clear how strong the cycle is going to be. We have recently shown that the ongoing Solar Cycle 25 is going to be a little stronger than the previous cycle. Here is the research paper: Physical link of the polar field buildup with the Waldmeier effect broadens the scope of early solar cycle prediction: Cycle 25 is likely to be slightly stronger than Cycle 24
   
• We have also shown that the amplitude of the solar cycle can be predicted after about three years of the previous cycle's polar field reversal (or a few years before the solar cycle minimum which is the usual time of the solar cycle prediction. This we have also shown in our previous publication: The Polar Precursor Method for Solar Cycle Prediction: Comparison of Predictors and Their Temporal Range 

• Reconstructed the solar surface magnetic field for the first time between 1915--1965 using Kodaikanal Solar Observatory data. This work is an outcome of the Indo-Russian bilateral collaboration. The research paper has been published in ApJL. The work has been highlighted on different platforms: DST, The Hindu, Anandabajar

• Mapped the magnetic field in the solar corona for the first time globally with an international team; the research has been published in a prestigious journal Science, The work has been highlighted in the Bengali newspaper: Anandabajar 

• Science Nugget based on our paper:  Magnetic Field Dependence of Bipolar Magnetic Region Tilts on the Sun: Indication of Tilt Quenching

• Received a prestigious INSA Young Scientist Medal (2019) from Indian National Science Academy. 

• Became the Active Members of the International Astronomical Union (IAU) and Astronomical Society of India (ASI).

• Science nuggets on the explanation of the double-peaks in the solar cycles; Also, see the published paper. 

• A science nugget published based on our recent work: Solar magnetic cycle and its variability in a 3D Babcock-Leighton dynamo model.

• Received prestigious:  ​​ ​​

                                          (i) Humboldt Research Fellowship from the Alexander von Humboldt Foundation, Germany (2021-2022).
                                          (ii) Ramanujan Fellowship from SERB/DST, India (2018-2023).

Recent Invited Talks:
 

• The origin of solar and stellar magnetic fields and cycles, 38th National Symposium on Plasma Science & Technology (PLASMA 2023), UPES Dehradun, India; Dec 4-8, 2023.
• Developments in the Babcock–Leighton Solar Dynamo Theory, IAU 365, Armenia, Yerevan, Aug 21-25, 2023.
• Solar and Stellar Magnetic Fields, Sikkim University, June 16, 2023.
• Understanding and Modelling the Magnetic Cycles of Sun and Sun-like stars , Dept. of Physics, Univ. of Hyderabad, Sept 26, 2022.
• Recent Developments in the Babcock-Leighton Dynamo Theory for the Solar Cycle, FM5, IAU General Assembly, Busan South Korea, Aug 2–11, 2022.
• Models for long-term cycle variabilities, Solar & stellar dynamos: a new era, International Space Science Institute, Bern, Switzerland, June 2022.
• Understanding the nonlinearity and predictability of the solar dynamo, ARIES Colloquium (online). April 2022
• "Some Recent Developments in the Babcock–Leighton Solar Dynamo Theory", in dynamo & solar cycle RSWG meeting, Max Plank Institute of Solar System Research, Germany, Feb 2022
• "Nonlinearities for the saturation of magnetic field in the Sun, International conference: IIA-50 “Advances in Observation and Modelling of Solar Magnetism and Variability", March 2021
• "Recent Developments in the Babcock–Leighton Solar Dynamo Theory, The 39th Annual Meeting of the Astronomical Society of India (ASI), 28-23 Feb 2021, Feb 2021.
• Understanding and Modeling the Magnetic Cycles of Sun and Sun-like Stars, Colloquium at NCRA, Pune, India, Jan 2020.
• Understanding the stellar magnetic cycles using dynamo modellings, Conference on Plasma Simulation (CPS-2020) at Institute for Plasma Research Gandhinagar, Jan 2020.
• Quenching and scatter in BMR tilts, Team Meeting at International Institute for Space Science, Bern, Switzerland, Nov 2019.
• Solar Magnetic Fields and Cycles: Understanding the Solar Dynamo and Differential Rotation, IIT-Delhi, New Delhi, India, May 2019.
• Why do the magnetic fields in sun and other stars vary irregularly?, Presentation for INSA Medal for Young Scientists, Apr 2019.

Currently, I am interested in taking a PhD student. Interested students qualified for the institute exam/interview (i.e., TA) or have an external fellowship like NET JRF can contact me. Students can email me (or call me at 8953043071 after 6 PM).