Photo

Varun Sheel

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

Research Interests

  • Study of impact of dust on the Martian lower atmosphere
  • Modeling neutral and ion chemistry in the lower atmosphere of Mars
  • Modeling atmospheric dynamics & chemistry in context with variabilty of trace gases
  • The tropical tropopause layer
  • Study of non-linear processes in tropospheric chemistry
For the above studies, I use data from planetary missions and a hierarchy of models ranging from simple models to complex three dimensional models (LMD Mars GCM,MOZART, WRF), 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. 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, doi:10.1007/s00382-016-3353-7, 2016

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  21. 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

  22. 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

  23. 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

  24. 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

  25. 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