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Dr. Sanjay Kumar Mehta

Ph.D.

Assistant Professor (Research)


Dr. Sanjay Kumar Mehta joined SRM Research Institute in November 2014 as an Atmospheric Science expert. After finishing his PhD from National Atmospheric Research Laboratory (NARL), Dept. of Space, Govt. of India, He moved to Kyoto University, Japan as a mission research fellow and later awarded as a JSPS postdoctoral fellow in the year 2012. The research contributions of Dr. Mehta are mainly devoted to understand the tropical tropopause over the Indian monsoon region which play an important role in the stratosphere-troposphere exchange processes and hence climate change. He has developed a few new methods to quantify the tropical tropopause  layer, multiple tropopause structure and the role of minor volcanoes to the upper troposphere and lower stratospheric thermal structure. Recently, He has established the diurnal structure of the Atmospheric Boundary Layer over a tropical station in the Indian Monsoon region. He is experienced in utilizing both space borne and ground based techniques especially Global Positing System (GPS) Radio occulation (RO) techniques, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), Radiosonde and Micro Pulse Lidar to study boundary layer and the tropical tropopause structures. He is also monitoring the upper troposphere and lower stratospheric temperature due to natural variability and anthropogenic climate change. 

Education

  • Ph.D. Atmospheric Sciences, National Atmospheric Research Laboratory (NARL) /Cochin University of Science and Technology, Kochi, India (February 2011)
  • M.Sc. Meteorology, Cochin University of Science and Technology, Kochi, Kerala, India (November 2004)
  • B.Sc. Mathematics (Physics and Chemistry), St. Columba’s college, VinobaBhave University, Hazaribag, Jharkhand, India (July 2001)

Employment History

  • Assistant Professor (Research), Research Institute, SRM University, Chennai (November 2014-present)
  • Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellow, Research Institute for Sustainable Humanosphere (RISH), Kyoto University (September 2012-August 2014) Advisor: Prof. Toshitaka Tsuda
  • Mission Research Fellow, Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan (June 2011-August 2012) Advisor: Prof. Toshitaka Tsuda
  • Postdoctoral Fellow, National Atmospheric Research Laboratory (NARL), Gadanki, A.P. India (May 2010-May 2011) Advisor: Dr. M. Venkat Ratnam
  • JSPS Young Researcher, Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan (June 2010-August 2010) Advisor: Prof. Toshitaka Tsuda
  • Senior Research Fellow, National Atmospheric Research Laboratory (NARL), Gadanki, A.P. India (April 2007-April 2010)Advisors: Dr. M. Venkat Ratnam and Dr. B. V. Krishna Murthy
  • Junior Research Fellow, National Atmospheric Research Laboratory (NARL), Gadanki, A.P. India, (April 2005-April 2007) Advisors: Prof. D. Narayana Rao and Dr. B. V. Krishna Murthy

Awards/Scholarship/Official Appreciation

  • Certificate of Appreciation for delivering a lecture to high School Students under JSPS’s dialogue program, Japan (2014)    
  • Japan Society for the Promotion of Science (JSPS) Award, Kyoto University, Kyoto, Japan (2012)   
  • Mission Oriented ResearchPostdoctoralAward,Research Institute for Sustainable Humanosphere (RISH) (2011)
  • Exchange Program for East Asian Young Researchers sponsored by JSPS, Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan (2010)     
  • 2ndprize in Earth System, Space and Engineering for poster presentation, 1st AP Science Congress, Osmania University, Hyderabad, India (2008)
  • Certificate for participation in International School on Atmospheric Radars (ISAR), National Central University, Chungli, Taiwan (2006)
  • National Atmospheric Research Laboratory (NARL)research fellow award, Department of Space, Govt. of India (2005)
  • GATE (Graduate Aptitude Test in Engineering) Qualification in Engineering Sciences, Ministry of Human Resources Development (MHRD), Govt. of India (2004)

Travel Grants

  • Partial travel support to attend 39thCOSPAR Scientific Assembly Mysore, India, July 2012 (Japan to India)
  • Full funding support to attend SPARC 4th General Assembly 2008, Bologna, Italy, September 2008.
  • Full funding support to attend the Reunion Island International Symposium, Saint-Gilles, Reunion Island, FRANCE, November 2007
  • Full funding support to attend the International School on Atmospheric Radars,NCU, Chungli, Taiwan, October 2006

Membership and Affiliation with the professional societies

  • Life member of Indian Science Congress Association (ISCA) (ID L30361)
  • Member of American Geophysical Union (AGU) and Reviewer for Journal of Geophysical Research-Atmospheres(ID 11520606).
  • Member of Japan Geophyical Union (JpGU) (ID 024322 )
  • Associate of COSPAR for Scientific Commission A on Space Studies of the Earth's Surface, Meteorology and Climate
  • Reviewer of Journal of Atmospheric and Solar- Terrestrial Physics
  • Reviewer of ActaMeteorologicaSinica, the Chinese Meteorological Society.
  • Reviewer of Atmospheric Chemistry and Physics.

  • GPS RO technique and its applications to atmospheric sciences
  • Atmospheric Boundary Layer (ABL) characteristics
  • Tropical Tropopause Layer (TTL) processes
  • StratosphereTroposphere Exchange Process
  • Stratospheric Aerosol
  • Climate Change

Research Project Grants

“Investigation of physical and chemical characteristics of the Tropical Tropopause Layer(TTL) in climate change perspective” funded by Department of Science and Technology(DST)–SERB, with total outlay: Rs. 21, 03,200 /- Period: 2016-2019 (3 years)

Lab Facility

Ground Based Observations

  • Micro Pulse Lidar

Satelliteobservations

  • GPS Radio Occultations (GPS RO)
  • Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)

Reanalysis datasets

  • NCEP, ERA Interim, MERRA

 


Research Fellow (Ph.D. Candidates)

  • Ms. A. Vanmathi (2015-2018)

Thesis Title: Investigation of the Physical and Chemical characteristics of the Tropical Tropopause Layer (TTL)

  • Mr. Saleem Ali C.K.(2016-2019)

Thesis Title:“Investigation on Effect of Cirrus Cloud on TropicalTropopause Layer”

  • Mr. A. Aravindhavel (2015-2019)

Thesis Title:“Role of stratospheric aerosol on the Upper troposphere lower stratospheric thermal structure”

Project Fellow (M.Sc.)

  • Ms. K.S. Lakshmi (2015-2017)

Title of Project: Algorithm development for retrieval of the atmospheric parameters from GPS RO signal

  • Mr. Saleem Ali C.K.(2014-2016)

Title of Project: “Investigation on Effect of Cirrus Cloud on TropicalTropopause Layer”

Alumni

  • Ms. M. Sarvani

 


Journal 

  • Mehta, S. K.,Ratnam, M. V., Sunilkumar, S. V., Narayana Rao, D., and Krishna Murthy, B. V.,Diurnal variability of the Atmospheric Boundary Layer height over a tropical station in the Indian Monsoon Region, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-542,  2016.IF 5.114 
  • Mehta,S. K., M. Fujiwara, T. Tsuda, J-P. Vernier, J. Atmospheric and Solar-Terrestrial Physics, 2015;Effect of recent minor volcanic Eruptions on Temperatures in the upper troposphere and lower stratosphere, 129:99-110. IF:1.474. 
  • Mehta, S. K., M. VenkatRatnam, and B. V. Krishna Murthy, 2013: Characteristics of the Multiple Tropopauses in the Tropics, JASTP, http://dx.doi.org/10.1016/j.jastp.2013.01.009, Volumes 95–96, April 2013, Pages 78–86
  • Mehta, S. K., M. VenkatRatnam, and B. V. Krishna Murthy, 2011: Multiple tropopauses in the tropics: A cold point approach, J. Geophys. Res., 116, D20105, doi:10.1029/2011JD016637.
  • Mehta, S. K., M. VenkatRatnam, and B. V. Krishna Murthy, 2011: Characteristics of the tropical tropopause over different longitudes, JASTP, doi:10.1016/j.jastp.2011.09.006, Volume 73, Issues 17–18, November 2011, Pages 2462–2473
  • Mehta, S. K.,M.VenkatRatnam, B.V. Krishna Murthy, 2010: Variability of the Tropical Tropopause over Indian Monsoon Region,J. Geophys. Res.,115, D14120, doi:10.1029/2009JD012655
  • Mehta, S. K.,B.V. Krishna Murthy,D.Narayana Rao, M.VenkatRatnam, K. Parameswaran, K. Rajeev, C. Suresh Raju, and Kusuma G Rao, 2008: Identification of tropical convective tropopause and its association with cold point tropopause, J. Geophys. Res.,113,D00B04,doi:10.1029/2007JD009625. 
  • M. Fujiwara, T. Hibino, S. K. Mehta, L. Gray, D. Mitchell, J. Anstey, Global temperature response to the major volcanic eruptions in multiple reanalysis datasets, 2015, Atmos. Chem. Phys., 15, 13507–13518, 2015 doi:10.5194/acp-15-13507-2015. IF: 5.053. 
  • Ratnam, M. V., G. Basha, M. R. Raman, S. K. Mehta, B. V. Krishna Murthy, and A. Jayaraman, 2011: Unusual enhancement in temperature and ozone vertical distribution in the lower stratosphere observed over Gadanki, India, following the 15 January 2010 annular eclipse, Geophys. Res. Lett., 38, L02803, doi:10.1029/2010GL045903.
  • Ratnam, M. V., G. Basha, M. R. Raman,S. K. Mehta, D. Nath, B. V. Krishna Murthy, M. Rajeevan,  S.VijayaBhaskara Rao and D.NarayanaRao, 2011: Sub-daily variations observed in Tropical Easterly Jet (TEJ) streams, JASTP, 73(2011)731–740
  • Ramkumar, T. K, K. Niranjankumar and S. K. Mehta, 2010: MST radar observations of characteristics of lower atmospheric high frequency gravity waves passing through the tropical easterly jet, J. Geophys. Res.,115, D24109, doi: 10.1029/2009JD013733.
  • Sunilkumar S.V., K. Parmeshwaran, K. Rajeev, B.V. Krishna Murthy, S.Meenu, S. K. Mehta,AshaBabu, 2010: Semitransparent cirrus clouds in the tropical tropopause layer during two contrasting seasons, JASTP, 72, 745-762. Narayana Rao ,D, M. VenkatRatnam, S. K. Mehta, DebashisNath , GhouseBasha, V. V. M. JagannadhaRao,,B. V. Krishna Murthy, T. Tsuda and Kenji Nakamura, 2009: Validation of the COSMIC data over Gadanki (13.48N, 79.2E): A tropical region, Terr. Atmos. Ocean. Sci., 20, 1, 59-70, doi: 10.3319/TAO.2008.01.23.01(F3C).
  • K. Rajeev, K.Parameswaran, S. Meenu, S.V. Sunilkumar,  Bijoy V. Thampi, C. Suresh Raju, B. V. Krishna Murthy, K. S. Jagannath, S. K. Mehta, D. Narayana Rao, Kusuma G. Rao, 2008: Observational assessment of the potential of satellite-based water vapour and thermal IR brightness temperatures in detecting semitransparent cirrus, Geophys. Res. Lett.,35,L08808,doi:10.1029/2008GL033393.
  • Narayana Rao. D., M. V .Ratnam, B. V. Krishna Murthy, V. V. M.  Jagannadha Rao, ­­S. K. Mehta, DebashisNath and GhouseBasha, 2007: Identification of Tropopause using Bending Angle profile from GPS Radio Occultation (RO): A Radio Tropopause Geophys. Res. Lett.,34, L15809,doi:10.1029/2007GL029709.

Proceedings

  • Mehta, S.K., T. Tsuda and M. Fujiwara, 2012: A Study on the variations of the tropical tropopause by using high-precision satellite data, RISH Mission Symposium, Kyoto University, Japan,2012,197, pp.163-167
  • Mehta, S. K.,B.V. Krishna Murthy, D. Narayana Rao, M. VenkatRatnam, K. Parameswaran, K. Rajeev, C. Suresh Raju, Kusuma G. Rao, 2009:  Studies on Diurnal Variation of the tropical Tropopause using MST Radar, CAWSES-India- Scientific Results (Phase-1), pp. 207-212.
  • Mehta, S. K.,DebashisNath, D.Narayana Rao and B.V.Krishna, Murthy, Day-to-day variations of the tropical tropopause characteristics, 2007. Proceedings of eleventh international conference on technical and scientific aspects of MST Radar (MST 11) , Macmillan ,pp. 759-762.
  • Mehta, S. K.,  D. Narayana Rao, B. V. Krishna Murthy,  K.Parameshwaran, K.Rajeev, C.Suresh Raju, Kusuma G. Rao, S.C.Chakravarty, and K. S. Jagannath, 2007: Characteristics of cold and convective tropical tropopause using MST radar, Proceedings of eleventh international conference on technical and scientific aspects of  MST Radar (MST 11), Macmillan ,pp. 621-624.
  • Ratnam, M. V., G. Basha, M. R. Raman, S. K. Mehta, B. V. Krishna Murthy, and A. Jayaraman, 2011: Unusual enhancement in temperature and ozone vertical distribution in the lower stratosphere observed over Gadanki, India, following the 15 January 2010 annular eclipse, Proceedings of National Workshop on Recent Observation of Solar Eclipses, pp 129-130.
  • Parameswaran, K., S.V. Sunilkumar ,Bijoy V Thampi , K. Rajeev , C. Suresh Raju , B.V. Krishna Murthy, S. K. Mehta, D. Narayana Rao and Kusuma G Rao, 2009:  Properties of cirrus clouds in the Tropical Tropopause Layer, CAWSES-India- Scientific Results (Phase-1), 187-196.
  • Rajeev, K., K.Parameswaran, S. Meenu, S.V. Sunilkumar, Bijoy V. Thampi, C. Suresh Raju, B. V. Krishna Murthy, K. S. Jagannath, S. K. Mehta, D Narayana Rao, and Kusuma G. Rao, 2009: Thin semitransparent cirrus clouds observed using KALPANA-1 VHRR and its inter-comparison with the Lidar-derived cirrus optical depth, CAWSES-India- Scientific Results (Phase-1), pp. 197-206.
  • Parameswaran, K., S.V. Sunilkumar, K. Rajeev, C. Suresh Raju, D. Narayana Rao, S. K. Mehta, B.V. Krishna Murthy, S.C. Chakravarthy, Kusuma G Rao, and K.S. Jagnath, 2007: Cirrus clouds in the Tropical Tropopause Layer, Proceedings of eleventh international conference on technical and scientific aspects of MST Radar (MST 11), Macmillan, pp. 552-558.

Thesis

  • Mehta S.K. (2010) Studies on Characteristics of tropical tropopause. Ph.D. Dissertation, Atmospheric Science, Department of Atmospheric Sciences, School of Marine Sciences, Cochin University of Science And Technology, Cohin-682016, Kerala, India
  • Mehta S.K. (2004) Active and weak Monsoon Situations. MSc Dissertation, Department of Atmospheric Sciences, School of Marine Sciences, Cochin University of Science And Technology, Cohin-682016, Kerala, India

 


M.Sc.Physics

  • PPY15101: Mathematical Physics (Theory)
  • PPY14208:Computational Methods and Programming (Theory and Lab)
  • PPY15206: Seminar-Research Initiative

Opportunities:

Candidates with good educational background in Physics /Atmospheric Science /Meteorology motivated towards research work in atmospheric science are welcome to the group. Please feel free to contact me. 

Specific Positions available:

  • To be updated.

Contact Details:
SRM Research Institute,
R-10, 13th floor, Central library building,
SRM University, Kattankulathur,
Chennai – 603 203.
Tel: +91-44-2741-7910
Email: sanjaykumar.r@res.srmuniv.ac.in
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