Varun Sheel Senior Professor, Head, Planetary Science Division E-mail: varun@prl.res.in Telephone: +91-79-26314412

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Research Interests

• Study the effect of Space Weather on Venus Atmosphere
• Study of impact of dust on the Martian lower atmosphere
• Physics of the Martian boundary layer layer
• Study of convective vortices (Dust Devils) on Mars
• Modeling neutral and ion chemistry in the lower atmosphere of Mars
• Modeling the climate of Mars and Venus with respect to dust, photochemistry and dynamics
• Radio Science Experiment for Venus and Mars

For the above studies, I use data from planetary missions and a hierarchy of models ranging from simple models to complex three dimensional models (PRL ion-dust model, PRL dust devil model, LMD Mars GCM), all of which I run on the 100 Tf HPC Linux cluster at PRL. The model to study the impact of dust on the Martian ionosphere has been developed in-house at PRL.

Selected Publications

1. Varun Sheel, S. Uttam and S.K. Mishra
   Electric fields due to charged dust within a vortex
   Physics of Plasmas, 32, 033704, https://doi.org/10.1063/5.0240977, 2025.


2. Varun Sheel
   The Lower Ionosphere of Mars: Modeling and Effect of Dust
   Oxford Research Encyclopedia of Planetary Science, https://doi.org/10.1093/acrefore/9780190647926.013.57, 2022


3. S. Uttam, Varun Sheel, D. Singh, C. E. Newman, M. T. Lemmon
   Characteristics of convective vortices and dust devils at Gale crater on Mars during MY33
   Planetary and Space Science, vol. 213, art. 105430, 2022


4. Varun Sheel, Shefali Uttam, S.K. Mishra
   Numerical simulation of dust lifting within a steady state dust devil
   Journal of Geophysical Research: Planets, vol. 126, article e2021JE006835, 2021.


5. Ashimananda Modak, Varun Sheel and Franck Lefèvre
   Competing pathways in odd oxygen photochemistry of the Martian atmosphere
   Planetary and Space Science, Volume 181, Article 104783, 2020


6. Tangential winds of a vortex system in a planetary surface layer
   Shefali Uttam, Deepak Singh and Varun Sheel
   Journal of Earth System Science, vol. 129, issue 2, 2020


7. Retrieval of Martian ozone and dust from SPICAM spectrometer for MY27-MY28
   A. Modak, Varun Sheel and Franck Montmessin
   Journal of Earth System Science, vol. 128, issue 6, article 0144, 2019.


8. Global and regional evaluation of a global model simulated AODs with AERONET and MODIS observations
   Varun Sheel, R.P. Guleria and S. Ramachandran
   Int. J. Climatol.. doi: 10.1002/joc.5367, 2018


9. Impact of tropical convection & ENSO variability in vertical distributions of CO and O3 over an urban site of India
   L.K. Sahu, Varun Sheel, M. Kajino et al.
   Clim Dyn, Vol. 49, pp 449–469, 2017


10. Long-term variability of dust optical depths on Mars during MY24–MY32 and their impact on subtropical lower ionosphere: Climatology, modeling, and observations
    Varun Sheel and S. A. Haider
    Journal of Geophysical Research, 121, 9123-9141, 2016.


11. Spatio-temporal variability of CO and O3 in Hyderabad (17°N, 78°E), central India, based on MOZAIC and TES observations and WRF-Chem and MOZART-4 models
    Varun Sheel, Jagat Bisht, Lokesh Sahu, and V. Thouret
    Tellus B, 68. doi:http://dx.doi.org/10.3402/tellusb.v68.30545, 2016


12. Temporal variations of atmospheric CO2 and CO at Ahmedabad in western India
    Chandra, N., Lal, S., Venkataramani, S., Patra, P. K., and Sheel, V.,
    Atmos. Chem. Phys., 16, 6153-6173, doi:10.5194/acp-16-6153-2016, 2016


13. Effects of convection and long-range transport on the distribution of carbon monoxide in the troposphere over India
    Chandra, N., S. Venkataramani, S. Lal, V. Sheel and A. Pozzer
    Atmospheric Pollution Research, 2016


14. Transport of tropospheric and stratospheric ozone over India: Balloon-borne observations and modeling analysis
    P.R. Sinha, L.K. Sahu, R.K. Manchanda, V. Sheel, M. Deushi, M. Kajino, M.G. Schultz, N. Nagendra, P. Kumar, D.B. Trivedi, S.K. Koli, S.K. Peshin, Y.V. Swamy, C.G. Tzanis, S. Sreenivasan
    Atmospheric Environment, 131, 228–242, 2016


15. Regional biomass burning trends in India: Analysis of satellite fire data
    L K Sahu , Varun Sheel, Kumud Pandey, Ravi Yadav, P Saxena, Sachin Gunthe
    Journal of Earth System Science, vol. 124, pp 1377-1387, 2015


16. Spatiotemporal characteristics of aerosols in India: Observations and model simulations
    S. Ramachandran,Sumita Kedia, Varun Sheel
    Atmospheric Environment, vol. 116, , Pages 225–244, doi:10.1016/j.atmosenv.2015.06.015, 2015


17. Secondary organic aerosol over an urban environment in a semi–arid region of western India
    A. K. Sudheer, R. Rengarajan, Varun Sheel
    Atmospheric Pollution Research, 6, 11-20, 2015


18. SO2 measurements at a high altitude site in the central Himalayas: Role of regional transport
    Naja, M., C. Mallik, T. Sarangi, Varun Sheel, Shyam Lal.
    Atmospheric Environment, 99, 392-402, doi:10.1016/j.atmosenv.2014.08.031, 2014


19. Seasonal and inter-annual variability of CO based on MOZAIC obesravtions, MACC reanalysis and model simulations over an urban site in India
    Varun sheel, L.K. Sahu, M. Kajino, M. Deushi, O. Stein, P. Nedelec.
    Journal of Geophysical Research, 119, 9123-9141, 2014.


20. Seasonal and inter-annual variability of tropospheric ozone over an urban site in India: A study based on MOZAIC and CCM vertical profiles over Hyderabad
    L.K Sahu, Varun Sheel , Mizuo Kajino , Makoto Deushi , Sachin Gunthe , P. R. Sinha , Bastien Sauvage , Valérie Thouret and Herman Smit.
    Journal of Geophysical Research, 119, 3615-3641, doi:10.1002/2013JD021215, 2014.


21. Spatio-temporal variation of biomass burning sources over South and Southeast Asia
    L.K Sahu and Varun Sheel
    Journal of Atmospheric Chemistry, 2013 (http://link.springer.com/article/10.1007/s10874-013-9275-4)


22. Characteristics of tropospheric ozone variability over an urban site in Southeast Asia: a study based on MOZAIC and MOZART vertical profiles
    Lokesh Sahu, Varun Sheel , Mizuo Kajino , Sachin Gunthe , Valée Thouret , Philippe Nedelec , Herman Smit
    Journal of Geophysical Research, 118, pages 8729–8747, doi:10.1002/jgrd.50662, 2013.


23. Variability in tropospheric carbon monoxide over an urban site in Southeast Asia
    L.K. Sahu, Varun Sheel, M. Kajino, P. Nedelec
    Atmospheric Environment, 68, Pages 243-255, 2013


24. Study of tropospheric CO and O3 enhancement episode over Indonesia during Autumn 2006 using the Model of Ozone and Related chemical Tracers (MOZART-4)
    S. Srivastava and Varun Sheel
    Atmospheric Environment, 67, Pages 53-62, 2013


25. Numerical simulation of the effects of a solar energetic particle event on the ionosphere of Mars
    Varun Sheel, S. A. Haider, P. Withers, K. Kozarev, I. Jun, S. Kang, G. Gronoff, and C. Simon Wedlund
    Journal of Geophysical Research, 117, A05312, doi:10.1029/2011JA017455, 2012


26. Calculated production and loss rates of ions due to impact of galactic cosmic rays in the lower atmosphere of Mars
    Varun Sheel and S.A. Haider
    Planetary and Space Science, 63-64, Pages 94-104, 2012


27. Surface distributions of O3, CO and hydrocarbons over the Bay of Bengal and the Arabian Sea during pre-monsoon season
    S. Srivastava, S. Lal, S. Venkataramani, S. Gupta and Varun Sheel
    Atmospheric Environment, 47, Pages 459-467, 2012


28. Effect of dust storms on the D region of the Martian ionosphere: Atmospheric electricity
    Haider, S. A., Varun Sheel, M. D. Smith, W.C. Maguire, and G. J. Molina-Cuberos
    Journal of Geophysical Research, 115, A12336, doi:10.1029/2010JA016125, 2010


29. Comparison of satellite observed tropospheric NO2 over India with model simulations
    Varun Sheel, Shyam Lal, Andreas Richter and John P. Burrows
    Atmospheric Environment, vol. 44, 3314-3321, 2010


30. Zonal Variability of Neutral Density, Temperature and Ion Production Rates in the Martian troposphere
    Varun Sheel, S.A. Haider, V.Singh, W.C.Maguire and G.J.Molina-Cuberos
    in Advances in Geosciences, Eds. Anil Bhardwaj et al., Vol. 19, pp. 225-235, World Scientific, Singapore, 2010


31. Zonal wave structures in the nighttime tropospheric density, temperature and in the D region ionosphere over Mars: Modeling and observations
    S.A. Haider, M. A. Abdu, I. S. Batista, J. H. A. Sobral, Varun Sheel, G. J. Molina-Cuberos, W.C. Maguire, and M.I. Verigin
    Journal of Geophysical Research, 114,A12315, doi:10.1029/2009JA014231, 2009


32. Longitudinal Distribution of the Dayside Ionosphere of Mars at High Latitude
    S.A. Haider, Varun Sheel, V. Singh, W.C. Maguire, G.J. Molina-Cuberos
    in Advances in Geosciences, Eds. Anil Bhardwaj et al., Vol. 15, pp. 25-52, World Scientific, Singapore, 2009


33. Model calculation of production rates, ion and electron densities in the evening troposphere of Mars at latitudes 67°N and 62°S: Seasonal variabilityty
    S.A. Haider, Varun Sheel, V. Singh, W. C. Maguire, and G. J. Molina-Cuberos
    Journal of Geophysical Research, 113, A08320, 2008