Janardhan Padmanabhan, FNA                                                                              
INSA Senior Scientist
Physical Research Laboratory
Ahmedabad - 380 009
INDIA

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<Thaltej-Dipole-Array>

A view of the 20,000 m2 dipole array at Thaltej, Ahmedabad, that was operated by PRL and used for IPS observations of the solar wind at 103 MHz.

Click on the picture for a full size image of the array.

 
 

<elec-button>  Papers Presented at Conferences & Symposia:


  1. Estimation of Solar Wind Velocity From the Three-Station IPS Observatory - India. 
    Janardhan, P.
    (
    Published in the Proc. of the Indo-U.S. Workshop on IPS and Solar Activity - Feb. 1988, pp. 83, Ahmedabad). 

  2. Enhanced Scintillation of Radio Source 2204+29 by Comet Austin (1989 c1) at 103 MHz. 
    Janardhan, P., Alurkar, S.K.,Bobra, A.D. and Slee, O.B. 
    (
    Presented at the 14th Meeting of the Astronomical Society of India - Jan. 29 to Feb. 1, 1991, PRL, Ahmedabad, India). 

  3. A Summary of Radio Observations of Enhanced Scintillations Due to Cometary Ion Tails at 103 MHz. 
    Janardhan, P
    (
    Presented at the Indo-U.S. Workshop on Interplanetary Scintillation and Propagating Disturbances, Ahmedabad, India, Sept. 1991). 

  4. Possible Contribution of a Solar Transient to Enhanced Scintillation Due to a Quasar. 
    Janardhan, P. and Alurkar, S.K. 
    (
    Presented at the Symposium on Solar Connection with Transient Interplanetary Processes (SOLTIP). Sept. 30 to Oct. 5, 1991, Liblice, Czechoslovakia). 

  5. Interplanetary Scintillations - Recent Results. 
    Janardhan, P
    (
    Invited Talk - Presented at the National Space Science Symposium (NSSS), March 11−14 1992 at the Physical Research Laboratory, Ahmedabad, India). 

  6. A 327 MHz Interplanetary Scintillation Survey of Radio Sources Over 6 steradian. 
    V. Balasubramanian, 
    P. Janardhan and S. Ananthakrishnan. 
    (
    Presented at the 6th Asia Pacific Regional Meeting on Astronomy, 16−18 August, 1993, Pune).

  7. Unique Observations of PSR 0950+08 and Possible Terrestrial Effects.
    M.R. Deshpande, H.O. Vats, P. Janardhan, A.D. Bobra, Harish Chandra, and G.D.Vyas.
    (
    Presented at the 6th Asia Pacific Regional Meeting on Astronomy, 16-18 August, 1993, Pune). 

  8. Latitudinal Variation of Solar Wind Velocity. 
    Ananthakrishnan, S., Balasubramanian, V., and Janardhan, P.
    (
    Presented at the 28th ESLAB Symposium " The High Latitude Heliosphere", April, 19−21 1994, Friedrichshafen, Germany). 

  9. IPS Observations of the Solar Wind at 327 MHz - A Comparison With Ulysses Observations.
    Janardhan, P., Balasubramanian, V., Ananthakrishnan, S., and Srivatsan, R.
    (
    Presented at the XVII Annual Meeting of the Astronomical Society of India, January, 17−20, 1996). 

  10. On the Nature of Compact Components of Radio Sources at 327 MHz.
    Balasubramanian, V., 
    Janardhan, P., Ananthakrishnan, S. and Srivatsan, R.
    (
    Presented at the XVII Annual Meeting of the Astronomical Society of India, January, 17−20, 1996). 

  11. Radio Observations of Transient Solar Wind Flows.
    Balasubramanian, V., 
    Janardhan, P., Srivatsan, R. and Ananthakrishnan, S.
    (
    Presented at the third SOLTIP meeting 14−18 October, 1996, Beijing, China). 

  12. Measurements of Solar Wind Velocities Close to the Sun Using Ulysses Radio Sounding Data.
    Janardhan, P., Bird, M. K., Edenhofer, P, Plettemeier, D., Wohlmuth, R., Asmar, S W., Patzö lt, M. and Karl, J. 
    (
    Presented at the XXII General Assembly of the European Geophysical Society, Vienna 21−25 April 1997). 

  13. Coronal Velocity Measurements with Ulysses: Multi-link Correlation Studies During two Superior Conjunctions. 
    Janardhan, P., Bird, M. K., Edenhofer, P, Plettemeier, D., Wohlmuth, R., Asmar, S W., Patzö lt, M. and Karl, J. 
    (
    Presented at the 8th Scientific Assembly of IAGA, Uppsala, Sweden August 4−15, 1997). 

  14. K-Band Radio Observations of Comet Hale-Bopp: Detections of Ammonia and (Possibly) Water 
    Bird, M. K., 
    Janardhan, P., Wilson, T. L., Huchtmeier, W.K., Gensheimer, P., and Lemme, C. 
    (
    Presented at the First International Conference on Hale-Bopp, Puerto de la Cruz, Tenerife, Spain, 2-6 February 1998). 

  15. Probing the Interplanetary Medium from the Ground.
    Janardhan, P.
    (
    Colloquium presented at the Australia Telescope National Facility (ATNF), Sydney, Australia, February, 11 1998). 

  16. Cross Correlation Measurements of Coronal Outflow Velocities During Two Solar Conjunctions of the Ulysses Spacecraft. 
    Janardhan, P., Bird, M. K., Edenhofer, P, Plettemeier, D., Wohlmuth, R., Asmar, S W., Patzö lt, M. and Karl, J. 
    (
    Presented at the 32nd COSPAR Scientific Assembly, Nagoya, Japan, July, 12−19 1998).

  17. Anisotropic Structure of the Solar Wind in its Region of Acceleration. 
    Efimov, A.I., Rudash, V.K., Bird, M.K., 
    Janardhan, P. , Patzö lt, M., Karl, J., Edenhofer, P. and Wohlmuth, R. 
    (Presented at the 32nd COSPAR Scientific Assembly, Nagoya, Japan, July, 12−19 1998). 

  18. Studying ``Space Weather'' from the Ground
    Janardhan, P.
    (
    Presented at the IV SERC school on Electromagnetic Probing of the Upper Atmosphere, Physical Research Laboratory, Ahmedabad, India, April, 6−29 1998). 

  19. The Ulysses Solar Corona Experiment: Coronal Radio Sounding Observations During the Solar Conjunctions in 1992 and 1995. 
    Bird, M.K., Asmar, S W., Edenhofer, P., 
    Janardhan, P ., Karl, J., Patzö lt, M., Plettemeier, D., Volland, H., and Wohlmuth, R. 
    (
    Presented at the Solar Wind 9, Nantucket Island, Massachusetts, USA, October 5−9, 1998). 

  20. Study of Solar Wind Transients Using IPS. 
    Ananthakrishnan, S., Kojima, M., Tokumaru, M., Balasubramanian, S., 
    Janardhan, P., Manoharan, P.K., and Dryer, M.
    (
    Presented at the Solar Wind 9, Nantucket Island, Massachusetts, USA, October 5−9, 1998). 

  21. Studying Solar Generated Heliospheric Disturbances using Interplanetary Scintillation Observations.
    Janardhan, P
    (
    Invited Talk - Presented at the XIX Meeting of the Astronomical Society of India, February 1-4, 1999, RRI, Bangalore, India). 

  22. 327 MHz Interplanetary Scintillation Observations during the Whole Sun Month - II Campaign. 
    P. Janardhan., V. Balasubramanian, S. Ananthakrishnan, M. Tokumaru and M. Dryer
    (
    Presented at the Solar Heliospheric and Interplanetary Environment (SHINE99) Workshop, Boulder, Colorado, USA, June 14−17, 1999). 

  23. Observations of Interplanetary Scintillation during the 1998 Whole Sun Month: a comparison between EISCAT, ORT and Nagoya data.
    Moran, P.J., A.R. Breen, A. Canals, R.A. Fallows, P.J.S. Williams, P. Janardhan., M. Tokumaru, J. Markkanen 
    (
    Presented at the 9th EISCAT International Workshop, Wernigerode/Harz, Germany, September 6−10 1999). 

  24. Observations of Interplanetary Scintillation during the 1998 Whole Sun Month: a comparison between EISCAT, ORT and Nagoya data.
    Moran, P.J., Ananthakrishnan, S., Balasubramanian, V., Breen, A.R., Canals, A., R.A. Fallows, P. Janardhan., Tokumaru, M., and Williams, P.J.S. 
    (Presented at the XXV General Assembly of the European Geophysical Society, Nice, France, April 2000). 

  25. Radio Detection of a Rapid Disturbance Launched by a Solar Flare.
    Janardhan P., White, S.M., and Kundu, M.R. 
    (
    Presented at the International Conference on Solar Eruptive Events, March 6−9, 2000, Catholic University of America, Washington, DC, USA). 

  26. The Role of IPS Technique in Detection and Tracking of Interplanetary Transients and its Application to Short Term Forecasts of Space Weather 
    Balasubramanian, V., Ananthakrishnan, S., 
    Janardhan, P . and Dryer, M. 
    (
    Presented at the Chapman Conference on Space Weather: Progress and Challenges in Research and Applications. March 20-24, 2000). 

  27. Subsidence of Solar Wind Over a Large Part of the Inner Heliosphere Monitored by IPS During 3 - 16 May 1999. 
    Balasubramanian, V., Ananthakrishnan, S., 
    Janardhan, P . and Srinivasan, S. 
    (
    Presented at the ISTP Science Workshop - Goddard Space Flight Centre, Maryland, USA, March 27-30, 2000 at the special session on "The Day the Solar Wind Went Away"). 

  28. A Comparitive Study of Scintillation Data from EISCAT, ORT and Nagoya during the 1998 and 1999 Whole Sun Months. 
    P.J. Moran, S. Ananthakrishnan, S. Balasubramanium, A.R. Breen, A. Canals, R.A. Fallows, 
    P. Janardhan, M. Tokumaru and P.J.S. Williams. 
    (
    Presented at the European Geophysical Society XXV General Assembly, Nice, April 25-29 200). 

  29. An Extremely Rapid Solar Flare Associated Disturbance Observed at 333 MHz.
    Janardhan, P., White, S.M., and Kundu, M.R. 
    (
    Presented at the Solar Physics Division (SP Annual Meeting, Lake Tahoe, USA, June 19-22, 2000). 

  30. Living With a Star - The Sun.
    Janardhan, P.
    (
    Invited Talk - Presented at the Workshop on Meteors, Astroids and Planets, PRL, Ahmedabad, India, February 26-March 2, 2001). 

  31. Subsidence of Solar Wind Over a Large Part of the Inner Heliosphere Monitored by IPS During 3− 16 May 1999.
    Janardhan, P. 
    (
    Presented at the Conference on "Probing the Sun with High Resolution" Udaipur Solar Observatory, PRL, Udaipur, India, October 16−12, 2001). 

  32. Understanding the Sun-Earth Connection.
    Janardhan, P.
    (
    Invited Talk - Presented at the XII National Space Science Symposium, Barkatulla University, Bhopal, India, February 25-28, 2002). 

  33. Interplanetary Scintillation Observations of the Large-Scale Solar Wind Subsidence Event of May 1999
    Janardhan, P., Balasubramanian, V., and Ananthakrishnan, S.
    (
    Presented at the First STEREO Workshop "The 3-D Sun and Inner Heliosphere: The STEREO View" Paris, March 18−20, 2002). 

  34. Fine Structure of the Solar Wind Turbulence Inferred from Simultaneous Radio Occultation Observations at Widely-Spaced Ground Stations. 
    Bird, M.K., 
    Janardhan, P., Efimov, A.I., Samoznaev, L.N., Andreev, V.E., Chashei, I.V., Edenhofer, P., Plettemeier, D., and Wohlmuth, R. 
    (
    Presented at the Solar Wind 10 Conference, Pisa, Italy, 17−21 June 2002). 

  35. Remote Sensing Interplanetary Disturbances. 
    Janardhan, P.
    (
    Invited Talk - Presented at the Workshop on "Radio and Optical probing of the Upper Atmosphere", PRL, Ahmedabad, India, February 6−8, 2003). 

  36. IPS Observations with the Ooty Radio Telescope
    Janardhan, P.
    (
    Invited Talk - Presented at the Symposium Entitled "ORT: Past Present and Future", Radio Astronomy Centre, Ooty, April 17−19 2003). 

  37. Magnetic Solar Cycle Related Heliospheric Density Anomalies 
    Ananthakrishnan, S., 
    Janardhan, P and Balasubramanian, V.
    (
    Presented at the IAU General Assembly, Sydney, Australia, July 2003). 

  38. Radio Observations of Rapid Acceleration in a Slow Filament Eruption/Fast CME Event.
    Kundu, M.R., White, S.M., Garaimov, V.I., Manoharan, P.K., Prasad Subramanian, Ananthakrishnan, S., and Janardhan, P.
    (Presented at the fall meeting of the AGU, 2003). 

  39. Enigmatic Solar Wind Disappearance Events: Insights from IPS Observations
    Janardhan, P. .
    (
    Invited Talk -Presented at the Conference on "Sun Earth Connections: Multiscale Coupling of Sun-Earth Processes", Hawaii, USA, Feb. 9−13 2004). 

  40. Resolving the Enigmatic Solar Wind Disappearance Event of 11 May 1999.
    Janardhan, P.
    (
    Invited Talk - Presented at the First Asia Oceanic Geophysical Society (AOGS Meeting, Singapore, July 5−9 2004).

  41. Meterwave Observations of the Solar Corona with the Giant Meterwave Radio Telescope (GMR and the Nancay Radio Heliograph (NRH).
    Prasad Subramanian, Claude Mercier, Alain Kerdraon, Monique Pick, S. Ananthakrishnan and Janardhan, P.
    (
    Presented at the XXVIII General Assembly of the International Union of Radio Science (URS, New Delhi, India, Oct. 23−29, 2005). 

  42. Locating the solar source of the extremely low-density, low-velocity solar wind flows of 11 May 1999
    Janardhan, P., Fujiki,K., Kojima, M. and Tokumaru, M.
    (
    Invited Talk Presented at the ''ILWS Workshop - The Solar Influence on the Heliosphere and Earth's Environment: Recent Progress and Prospects" Goa, India, Feb. 19−24, 2006). 
  43. Low Density Solar Wind Anomalies. 
    Janardhan, P. 
    (
    Invited Talk Presented at the International Colloquium "Scattering and Scintillation in Radio Astronomy", 19−23 June 2006, Pushchino, Moscow, Russia). 

  44. Electron acceleration in solar noise storms 
    Prasad Subramanian, Peter A. Becker, Claude Mercier, Steve White, Alain Kerdraon, Monique Pick, S. Ananthakrishnan, P. Janardhan
    (
    Presented at the second UN/NASA workshop on the International Heliophysical Year and basic Space Science , IIAP, Bngalore Nov. 27−Dec. 1 2006). 

  45. Solar observations during solar minima with Brazilian Decimetric Array. 
    J.F. Valle, R. Ramesh,
     P. Janardhan , J. R. Cecatto and H. S. Sawant.
    (
    Presented at the Eighth Latin American Conference on Space Geophysics (VIII -COLAG Mexico, July 17−21, 2007). 

  46. Studies of Long Lasting Low Density Solar Wind Anomalies at 1 AU. 
    P. Janardhan, J. F. Valle and H. S. Sawant
    (
    Presented at the Eighth Latin American Conference on Space Geophysics (VIII -COLAG Mexico, July 17−21, 2007 ). 

  47. The Solar Wind Disappearance Event of 11 May 1999: Source Region Evolution. 
    Mason, H.E., Janardhan, P., and Tripathi, D.
    (
     Presented at the National Astronomy meeting of the Royal Astronomical Society, 31 March−04 April 2008, Queens University Belfast, UK). 

  48. Source Region Evolution of the Solar Wind Disappearance Event of 11 May 1999 
    Janardhan, P., Tripathi, D. & Mason, H.E.
    (
     Presented at the European Solar Physics Meeting (ESPM12), 8−12 September 2008, Freiburg, Germany). 

  49. The Global Electromagnetic Moon Surveyor. 
    S. Ananthakrishnan, J. E. S. Bergman, L. Blomberg, F. Bruhn, T. D. Carozzi, L. K. S. Daldorff, A. I. Eriksson, S. Gurubaran, N. Ivchenko, 
    P. Janardhan, P. Kale, V. Korepanov, J. Lazio, H. Lundstedt, A. Marusenkov, S. M. Mohammadi, H. Rothkaehl, B. Thidé, J.-E. Wahlund, K. Weiler, and L. Åhlén.
    (
     Presented at the DGLR International Symposium “To Moon and beyond", 15−17 September, 2008, Bremen, Germany). 

  50. When the Solar Wind Vanishes: Causes on the Sun, Effects at the Earth. 
    Janardhan, P. .
    (
    Invited Talk -Presented at the 27th ASI Meeting, February 18 − 20, 2009, Bangalore, India. ). 

  51. The Deepest Solar Minimum in 100 Years: Earliest Inner Heliospheric Signatures 
    Janardhan, P. .
    (
    Invited Talk -Presented IUCAA, Pune, Sept. 4−7 2011 ). 

  52. Declining solar activity in solar cycles 22 and 23 and their inner heliospheric signatures 
    Janardhan,P., (2012). 
    (
     Presented at the 39th COSPAR meeting, July 14-22, 2012, Mysore, India ). 

  53. Quasi-periodic variations in solar photospheric fields in the build-up to the deep minimum between solar cycles 23 and 24. 
    Janardhan,P., (2012). 
    (
     Presented at the International Symposium on Solar Terrestrial Physics, November 6-9, 2012, IUCAA, Pune, India). 

  54. Earliest Solar and Heliospheric Signatures of the Build-up to the Deepest Solar Minimum in 100 years 
    Janardhan,P., (2012). 
    (
     Presented at Workshop on Coronal Magnetism - Connecting Models to Data and the Corona to the Earth", May 2012, Boulder, CO, USA.

  55. Extremely low density solar wind events observed at 1 AU and their space weather consequences. 
    Janardhan, P. .
    (
    Invited Talk -Presented at the High Altitude Observatory, Boulder, Colorado, USA, 31 May 2012 ). 

  56. Peculiar behavior of solar polar fields during solar cycles 21-23: Correlation with meridional flow speed 
    Susanta Kumar Bisoi, Janardhan,P., (2013).  Proc. IAU Symp. 294,   8, 81−82  (DOI) 10.1017/S1743921313002287.
    (
     Presented at the IAU Symposium 294“Solar and Astrophysical Dynamos and Magnetic Activity", August, 2012, Beijing, China). 

  57. Asymmetry in the periodicities of solar photospheric fields: A probe to the unusual solar minimum prior to cycle 24
    Susanta Kumar Bisoi, Janardhan,P., (2013).  Proc. IAU Symp. 294,   8, 85−86  (DOI) 10.1017/S1743921313002305.
    (
     Presented at the IAU Symposium 294“Solar and Astrophysical Dynamos and Magnetic Activity", August, 2012, Beijing, China). 

  58. Interplanetary scintillation signatures in the inner heliosphere of the deepest solar minimum in the past 100 years
    Susanta Kumar Bisoi, Janardhan,P., (2013).  Proc. IAU Symp. 294,   8, 83−84  (DOI) 10.1017/S1743921313002299.
    (
     Presented at the IAU Symposium 294“Solar and Astrophysical Dynamos and Magnetic Activity", August, 2012, Beijing, China). 

  59. Observations of a geomagnetic SI+−SI- pair and associated solar wind fluctuations
    Susanta Kumar Bisoi, 
    Janardhan,P., (2013).  Proc. IAU Symp. 294,    8, 543−544 (DOI)  10.1017/S1743921313003141.
    (
     Presented at the IAU Symposium 294“Solar and Astrophysical Dynamos and Magnetic Activity", August, 2012, Beijing, China). 

  60. The deepest solar minima in 100 years : Heliospheric micro-turbulence levels from 327 MHz IPS observations and periodicities in solar photospheric fields 
    Janardhan,P.,Susanta Kumar Bisoi, Chakrabarti, D.and Ananthakrishnan, S. (2013). 
    (
     Presented at the Asia-Pacific regional URSI conference, Taipei, Taiwan, September 3−7, 2013 ). 

  61. Steady decline in solar polar magnetic fields and heliospheric microturbulence levels: Are we headed towards a Maunder minimum?
    Susanta Kumar Bisoi  Janardhan, P.  and S. Ananthakrishnan, (2014).
    (Presented at the 40th General Assembly, Beijing, China, August 16−23, 2014 
  1. Declining Solar Polar Fields and Heliospheric Micro-turbulence: Are we Heading Towards Another Maunder Minimum?
    Janardhan, P.
    (Invited talk Presented at the conference on Plasma Processes in Solar and Space Plasmas at Diverse Spatio-Temporal Scales: Upcoming Challenges in Science and Instrumentation, 26-28 Mar. 2014)
  1. Are we on the verge of a Maunder –Like Grand Solar Minimum
    Janardhan, P.
    (Invited talk - Presented at the CSPM 2015 – “Ground Based Solar Observations in the Space Instrumentation Era” - Coimbra, Portugal, 5-9, October 2015.”
  1. A 20 year decline in solar magnetic fields – heliospheric response and possible consequences?
    Janardhan, P.
    (Invited Talk – Presented at the conference on “New Paradigms for the Heliosphere'', Physikzentrum Bad Honnef, Germany, 29 June - 03 July 2015.
  1. Are we on the verge of a Maunder –Like Grand Solar Minimum
    Janardhan, P.
    (Invited Colloquium - - MPIFR – Bonn, Germany, 26 June 2015)
  1. Declining Solar Polar Fields and their Signatures in the Solar Wind: Implications to near Earth Space
    Janardhan, P.
    (Invited talk - 1st URSI Atlantic Radio Science Conference (URSI AT-RASC), Gran Canaria, May 18 - 22, 2015)
  1. Declining  Solar Photospheric Magnetic fields and Solar wind Micro-turbulence
    Janardhan, P.
    (Invited talk - Presented at the Dynamic Sun: II. Solar Magnetism from Interior to the Corona, Cambodia, Feb 12-16, 2018).
  1. Solar Activity - Past, Present and Near Future
    Janardhan P
    ( Invited Talk -Presented at the ISRO Structured Training Program (STP) in Space Sciences – PRL, March 5--9, 2018).
  1. The Sun-Earth Connection
    Janardhan P
    ( Plenary Talk - Presented at the National Symposium on "Advancements in Geospatial Technology for Societal Benifits", Space Application Centre, Ahmedabad, 5--7 December 2018).
  1. Beyond the Mini Solar Maximum of Cycle 24: The Amplitude of Solar Cycle 25 and the Evolution of the Terrestrial Magnetosphere
    Janardhan P
    ( Invited Talk -Presented at the National Space Science Symposium, Savitri Bhai Phule University, Pune, 29-31, January 2019).
  1. Solar Polar Fields During Cycle 24: An Unusual Polar Field Reversal.
    Janardhan P  and Susanta Kumar Bisoi
    ( Presented at the URSI Asia Pacific Radio Science Conference 2019, (APRASC 2019) New Delhi, 9-15, March 2019).
  1. High Resolution Imaging of Coronal Type III Bursts: First MUSER Solar Radio Observations.
     Susanta Kumar Bisoi, and Janardhan P
    ( Presented at the URSI Asia Pacific Radio Science Conference 2019, (APRASC 2019) New Delhi, 9-15, March 2019).
  1. A Decimetric Emission Source 500'' away from a Flaring Site.
     Susanta Kumar Bisoi, and Janardhan P
    ( Presented at the URSI Asia Pacific Radio Science Conference 2019, (APRASC 2019) New Delhi, 9-15, March 2019).
  1. Declining solar polar fields, the terrestrial magnetosphere and the forthcoming solar cycle
    Janardhan P
    ( Invited talk - Presented at the workshop on International Space Weather Initiative (ISWI) in collaboration with the United Nations Office of Outer Space Affairs during May 20-24, 2019).

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