Group Members

Prof. T. R. Ariyaratne
Prof. D. U. J. Sonnadara
Dr. K. P. S. C. Jayaratne
Dr. I. M. K. Fernando
Dr. R. Lelwala
Dr. C. M. Edirisinghe

Past Ph. D. Postgraduate Students

Ms. W. Perera
Dr. P. Liyanage
Dr. C.M. Edirisinghe
Dr.S.R. Sharma
Mr. J.A.P. Bodhika

Research Activities

Atmospheric Electricity Research

Studies on air-earth conduction current density under fair-weather conditions
Measurement of atmospheric electricity parameters
Development of a mesoscale dispersion model for Sri Lanka

Thunderstorm Electricity and Lightning

Research Propagation effect on lightning generated electromagnetic fields
Studies on lightning generated EM field characteristics of tropical thunderstorms: With a view of providing a complete source of
information to serve engineering needs
Measurement of lightning generated electromagnetic fields over the sea
Correlation between lightning and rainfall
Experimental and numerical study of protective components in a modern environment
Characteristics of electrical discharges with special attention to optical radiation

Implementation of a Lighting Location System for Sri Lanka

Lightning density maps
Characteristicsof cloud-to-ground lightning discharges

Financial Support

International Science Programs (ISP), Uppsala University, Sweden
National Science Foundation (NSF), Sri Lanka
University of Colombo, Sri Lanka

Research Links and Collaborations

International

Meteorology, Department of Earth Sciences, Uppsala University, Sweden
Division of Lightning and Electric Research, Uppsala University, Sweden

Local

Department of Meteorology, Sri Lanka
Tea Research Institute, Sri Lanka
Sri Lanka Standards Institution, Sri Lanka
Industrial Technology Institute (ITI)

Research Publications

Conference Proceeding

  1. The effect of distorted atmospheric electric fields on the measurements of small ion densities, K. P. S. C. Jayaratne et al., J. Inst. Phys., Sri Lanka; 4, 18-24, Colombo 1988.
  2. Polar conductivity profiles of the lower atmosphere under fair-weather conditions, K. P. S. C. Jayaratne et al. J. Inst. Phys., Sri Lanka; 4, 25-31, Colombo, 1988.
  3. Design and construction considerations of an EMI hardened lighting instrumentation, V. Suka et al. Proc. 19th Int. Conf. Lightning Protection, Austria, 1.1 pp. 1-9, 25-29 April 1988.
  4. Correlation between temperature and space charge density fluctuation, K. P. S. C. Jyaratne et al. Proc. Sri Lanka Assoc. Advmt. Sci., E1-01, 94, Colombo, Dec. 1989.
  5. Effect of propagation across a cost line on the electromagnetic fields from lightning return strokes. K. P. S. C. Jyaratne and Vernon, Cooray, Proc. 20th Int. Conf. Lightning Protection, Interlaken, Switzerland, pp. 6.1/1-6, 1990.
  6. The effect of distorted atmospheric electric field lines on the measurements of small ion number densities and related electrical parameters, K. P. S. C. Jayaratne et al. 8th Int. Conf. Electrostatic, Oxford, U. K., 1991.
  7. Electrical aspects of several local storms in the tropics, K. P. S. C. Jayaratne, SAARC Regional Seminar on Severe Local Storms, Colombo, Sri Lanka, 7-11 October, 1991.
  8. On the nature of tropical lighting observed in Sri Lanka-I, K. P. S. C. Jayaratne, Proc. Sri Lanka Assoc. Advmt. Sci., E1-10, 132, Colombo, Dec. 1991.
  9. HF radiation at 3MHz from negative lighting discharges to the ground, K. P. S. C. Jayaratne, Proc. Sri Lanka Assoc. Advmt. Sci., E1-12,134, Colombo, Dec. 1991.
  10. Effect of nearby grounded objects on the measurements of atmospheric small ions, K. P. S. C. Jayaratne et al. Pro. 9th Int. Conf. Atmos. Electricity, Leningrad, USSR, pp. 611-614, June 1992.
  11. Preliminary studies on the measurements of air-earth conduction current density in Sri Lanka, K. P. S. C. jayaratne, R. Lelwala, J. Inst. Phys., Sri Lanka, 9, 1-5, Colombo, 1993.
  12. Ground-station measurements of size and charge of raindrops from tropical rain clouds, K. P. S. C. Jayaratne and J. P. Gamalath, J. Inst. Phys., Sri Lanka, 9, 6-12, Colombo, 1993.
  13. On the theory of electrification of atmospheric due to ground water evaporation, K. P. S. C. Jayaratne J. Inst. Phys., Sri Lanka, 10, 6, Colombo, March, 1993.
  14. Behavior of Sri Lankan honeybees in simulated fair-weather and thunderstorm electric field conditions, K. P. S. C. Jayaratne and H. M. U. P. H. Denuwara, Proc. Sri Lanka Assoc. Advmt. Sci., E1-15,195, Peradeniya, Dec. 1993.
  15. A novel technique to measure the body charge of honeybees, K. P. S. C. Jayaratne and H. M. U. P. H. Denuwara, Proc. Sri Lanka Assoc. Advmt. Sci., E1-16, 196, Peradeniya, Dec. 1993.
  16. Electronic speech recognition system, N. A. D. S. M. Dharmathileke et al. J. Inst. Phys., Sri Lanka, 10, 1, Colombo, March, 1994.
  17. The peak, risetime and half-width of lightning generated electric field derivatives over finitely conducting ground, M. Fernando and V Cooray, 10th International Conference on Electromagnetic Compatibility, 1997
  18. The fine structure of positive return stroke radiation fields – a collaborative study between researches from Sweden and Denmark, V. Cooray et al.,24th International Conference on Lightning Protection, UK (1998)
  19. Analysis of Swedish Lightning using LLP data, M. Fernando et. al., 24th International Conference on Lightning Protection, UK (1998).
  20. Submicrosecond structure of electric field pulses generated by cloud flashes, M. Fernando and V. Cooray, 24th International Conference on Lightning Protection, UK (1998).
  21. Chaotic pulse trains that mainly associated with subsequent strokes, C. Gomes et. al., 24th International Conference on Lightning Protection, UK (1998)
  22. Space Charge Layers Created by Corona and Electrode Effects at Ground Level Below Thunderclouds, S. Israelsson and R. Lelwala, 3rd International Workshop on physics of lightning, 15-20, France, 1997
  23. Effect of Wind on Horizontal wire antenna collecting atmospheric air-earth current, R. Lelwala, T.J. Tuomi, S. Israelsson and K.P.S.C. Jayaratne, 11th International Conference on Atmospheric Electricity, June 1997.
  24. Preliminary results of implementing an automated system in Sri Lanka to locate lighting ground flashes, I.M.K. Fernando, D.U.J. Sonnadara, K.P.S.C. Jayaratne, S. Namasivayam and T.R. Ariyaratne, SLAAS, Proc. 54th Annual Session, Sri Lanka (December 1998) 247.
  25. The role of site selection on localising ground flashes in an automated lighting detection network, D.U.J. Sonnadara, I.M.K. Fernando, S. Namasivayam, T.R. Ariyaratne, K.P.S.C. Jayaratne and K.R.A. Bandara, IPSL, Proc. 15th Technical Session, Sri Lanka (March 1999).
  26. Some features of lightning ground flash activities observed in tropical thunderstorms, A.B. Weerasekera, I.M.K. Fernando, D.U.J. Sonnadara, R. Lelwala, K.P.S.C. Jayaratne, S. Namasivayam, K.R.A. Bandara, C. Gomes, T.R. Ariyaratna, SLAAS, Proc. 55th Annual Session, Sri Lanka (December 1999).
  27. On the accuracy of locating lightning ground flashes using two or more direction finding stations, D.U.J. Sonnadara, I.M.K. Fernando, S. Namasivayam, K.P.S.C. Jayaratne, K.R.A. Bandara, R. Lelwala, A.B. Weerasekera, C. Gomes, T.R. Ariyaratne, SLAAS, Proc. 55th Annual Session, Sri Lanka (December 1999).
  28. A study of LLP systems and their performance in locating ground flashes in Sri Lanka (1998-1999), D.U.J. Sonnadara for LLP group, IPSL, Proc. 16th Technical Session, Sri Lanka (2000)
  29. Measurements of lightning peak currents in the first return stroke of negative cloud to ground flashes, A.B. Weerasekera, J.P. Liyanage, D.U.J. Sonnadara and I.M.K. Fernando, SLAAS, Proc. 56th Annual Session, Sri Lanka (2000).
  30. A comparison between some characteristics between positive and negative cloud to ground flashes observed in Sri Lanka and their seasonal variations, J.P. Liyanage, A.B. Weerasekera, D.U.J. Sonnadara and I.M.K. Fernando, SLAAS, Proc. 56th Annual Session, Sri Lanka (2000).
  31. Preliminary results of Markov model approach in forecasting wet/dry condition over short periods, H.K.W.I. Perera, D.U.J. Sonnadara and D.R. Jayewardene, SLAAS, Proc. 56th Annual Session, Sri Lanka (2000).
  32. Lightning ground flash activities in monsoon thunderstorms over Sri Lanka, A.B. Weerasekera, J.P. Liyanage, I.M.K. Fernando, D.U.J. Sonnadara and T.R. Ariyaratne, Proc. Annual Sessions – 2000, Faculty of Science, University of Colombo, (2000).
  33. Simulation study of the effect of random and systematic errors in magnetic direction finding stations, J.P. Liyanage, A.B. Weerasekera, D.U.J. Sonnadara and I.M.K. Fernando, Proc. Annual Sessions – 2000, Faculty of Science, University of Colombo, (2000).
  34. Measurements of lightning peak currents in the first return stroke of negative cloud-to-ground flashes, A.B. Weerasekera, D.U.J. Sonnadara, I.M.K. Fernando, J.P. Liyanage, R. Lelwala and T.R. Ariyaratne, Singapore J. of Physics, submitted (2001)
  35. Performance comparison between the magnetic direction finding technique and time-of-arrival technique, D.U.J. Sonnadara, C.M. Edirisinghe and I.M.K. Fernando, IPSL, Proc. 17th Technical Session, Sri Lanka (2001).
  36. Construction of a high speed buffer amplifier to measure lightning generated vertical electric fields, C.M. Edirisinghe, I.M.K. Fernando and D.U.J. Sonnadara, IPSL, Proc. 17th Technical Session, Sri Lanka (2001).
  37. Some characteristics of cloud to ground lightning obtained with lightning direction finding systems in Sri Lanka, I.M.K. Fernando, A.B. Weerasekera, J.P. Liyanage and D.U.J. Sonnadara, SLAAS, Proc. 57th Annual Session, Sri Lanka (2001).
  38. A simulation study on the correction of the systematic errors in a network of magnetic direction finding network, J.P. Liyanage, D.U.J. Sonnadara and I.M.K. Fernando, SLAAS, Proc. 57th Annual Session, Sri Lanka (2001).
  39. C. Gomes, R. Thottappillil, and V. Scuka, Bipolar electric field pulses in lightning flashes over Sweden, 12th International Symposium on EMC, Zurich, Switzerland, 31FA, 1997
  40. C. Gomes and V. Cooray The dependence of the total leader return stroke field changes on the orientation of a segment of the leader channel, 13th International Symposium on EMC, Zurich, Switzerland, 106P2, 1999
  41. C. Gomes and V. Cooray Return stroke models: The concept, 2nd International Symposium on Lightning and Mountains, Chamonix, France, A2.2, 1997
  42. C. Gomes, V. Cooray, M. Fernando and C. Jayaratne, Chaotic pulse activities mainly associated with negative subsequent return strokes, 24th International Conference on Lightning Protection, Birmingham, UK, 3b.2, 1998
  43. C. Gomes and V. Cooray, On theoretical approaches to estimate lightning return stroke currents, 11th International Symposium on High Voltage Engineering, London, UK, 1999
  44. C. Gomes, L. Gao, V. Cooray, and F. Roman, Breakdown characteristics of 250mm and 500mm sparks along insulating surfaces, 11th International Symposium on High Voltage Engineering, London, UK, 1999
  45. C. Gomes, L. Gao and V. Cooray, Breakdown characteristics of long sparks over insulating surfaces, Nordic Insulation Symposium, Copenhagen, Denmark, 1999
  46. C. Gomes, and V. Cooray, Characteristics of cloud flashes, 14th International Symposium on EMC, Zurich, Switzerland, 2001
  47. G. A. C. Gomes and K. P. S. C. Jayaratne, Multiplicity of negative return strokes of lightning flashes observed in Colombo, Proceedings of Sri Lanka Association for the Advancement of Science, 54th Annual Session, E1- 37, 1997
  48. K. P. S. C. Jayaratne and G. A. C. Gomes, Number of thunder days per year and other lightning occurrence characteristics in Colombo thunderstorms, Proceedings of Sri Lanka Association for the Advancement of Science, 52nd Annual Sessions E1-05, 340, Colombo, Nov. 1995
  49. A. B. Weerasekara, I.M.K. Fernando, D.U.J. Sonnadara, R. Lelwala, S. Namasivayam, K.P.S.C. Jayaratne, T.R. Ariyaratne, K.R.A. Bandara, C. Gomes, Some features of lightning ground flash activities observed in tropical thunderstorms, Proceedings of Sri Lanka Association for the Advancement of Science, 56th Annual Sessions E1, Colombo, Dec. 1999
  50. C. Gomes and V. Cooray, Temporal characteristics and absolute amplitudes of cloud flashes, Proceedings of Technical Sessions, Institute of Physics, Sri Lanka, March, 2000
  51. C. Gomes, Lightning electromagnetic environment, Proceedings of Technical Sessions, Institute of Physics, Sri Lanka, March, 2000
  52. C. Gomes and Cooray, Leader fields due to a lightning channel with an inclined upper section, Journal of Physics, Sri Lanka (IPSL), 2001 (accepted)
  53. C. Gomes, Optimisation of computer-aided interactive physics teaching in Sri Lanka, Sri Lanka Journal of Physics (Eastern University), 2001 (submitted)
  54. C. Gomes, Knowledge of Lightning and Lightning Protection of the Colombo Public, Colombo University Technical Sessions, 2000
  55. G.A.C. Gomes and K.P.S.C. Jayaratne, A review of microsecond scale field pulses of lightning flashes, Proceedings of Technical Sessions, Institute of Physics, Sri Lanka, March, 1996
  56. Effect of distance on the measurement of multiplicity and peak currents of lightning direction finding systems, J.P. Liyanage, C.M. Edirisinghe, D.U.J. Sonnadara and I.M.K. Fernando, SLAAS, Proc. 58th Annual Session, Sri Lanka (December 2002).
  57. Development of microcontroller based high capacity standalone data acquisition systems, B.W.S.P. Fernando, P.C.C.P.W. Goonetilleke, I.M.K. Fernando and D.U.J. Sonnadara, SLAAS, Proc. 58th Annual Session, Sri Lanka (December 2002).
  58. Microcontroller embedded web server with flash support, P.C.C.P.W. Goonetilleke, B.W. S.P. Fernando, I.M.K. Fernando and D.U.J. Sonnadara, SLAAS, Proc. 58th Annual Session, Sri Lanka (December 2002).
  • Journal Publications
  1. An investigation of sources of errors by space charge measurements using the Obolensky filter method, E. Knudsen et al. J. Atmos. Terr. Phys., 51(6), 529-531, 1989.
  2. The lighting HF radiation at 3MHz during leader and return stroke processes, K. P. S. C. Jayaratne and V. Cooray, J. Atmos. Terr. Phys., 56(4), 493-501, 1994.
  3. Measurements of space charge density over flat ground in nealy neutral stratified atmospheric surface layer, R. Lelwala S. Israelsson and K.P.S.C. Jayaratne, Journal of Atmospheric and Electricity, Vol 17, No. 2, pp. 59-68, 1997
  4. Space charge density measurements downwind from a traffic route, S. Israelsson and R. Lelwala, Journal of Atmospheric Research, 51, pp 301-307,1999.
  5. Study of the performance of direction finding stations prior to the implementation of a Lightning Location System in Sri Lanka, I.M.K. Fernando, D.U.J. Sonnadara, K.P.S.C. Jayaratne, T.R. Ariyaratne, S. Namasivayam and K.R.A. Bandara, Ceylon Journal of Science, 4 (1998) 77.
  6. Propagation of lightning generated transient electromagnetic fields over finitely conducting ground, V. Cooray, M. Fernando, T. Sotensen, T Gotschl and Aa Pedersen, Journal of Atmospheric and Solar-Terrestrial Physics, 62, pp 583-600, (2000)
  7. Locating Cloud-to-Ground lighting flashes with simultaneous two station measurements, D.U.J. Sonnadara, A.B. Weerasekera, I.M.K. Fernando, R. Lelwala, K.P.S.C. Jayaratne, T.R. Ariyaratne, S. Namasivayam and K.R.A. Bandara, Sri Lankan J. of Phys., 1 (2000) 11-22
  8. Activity of Cloud-to-Ground lightning observed in Sri Lanka and in the surrounding area of the Indian Ocean, A.B. Weerasekera, D.U.J. Sonnadara, I.M.K. Fernando, J.P. Liyanage, R. Lelwala and T.R. Ariyaratne, Sri Lankan J. of Physics, accepted (2001)
  9. C. Gomes and V. Cooray, Long impulse currents associated with positive return strokes, Journal of Atmospheric Solar-Terrestrial Physics, 60/7, 693-699, 1998
  10. V. Cooray and C. Gomes, Estimation of peak return stroke currents, current derivatives and return stroke speeds from measured fields, Journal of Electrostatics, 43/3, 163-172,1998
  11. C. Gomes, V. Cooray and C. Jayaratne, Comparison of preliminary breakdown pulses observed in Sweden and in Sri Lanka, Journal of Atmospheric Solar-Terrestrial Physics, 60/10, 975-979, 1998
  12. C. Gomes and V. Cooray, Correlation between the optical signatures and current waveforms of long sparks: Applications in lightning research, Journal of Electrostatics, 43/4, 267-274,1998
  13. J. Bendjamin, C. Gomes, V. Cooray, Remote sensing of electrostatic discharges (ESD) through optical and magnetic radiation fields, IEEE Transactions on Dielectrics and Electrical Insulation, 896-899, 1999
  14. C. Gomes and V. Cooray, Concepts of return stroke models, IEEE Transactions on Electromagnetic Compatibility, 2000
  15. C. Gomes and V. Cooray, Radiation field pulses associated with the initiation of positive cloud to ground lightning flashes, Accepted by Journal of Atmospheric Solar-Terrestrial Physics, 1999
  16. Some Properties of lightning ground flashes observed in and around Sri Lanka and their seasonal variations, J.P. Liyanage, D.U.J. Sonnadara, I.M.K. Fernando, A.B. Weerasekara, R. Lelwala and T.R. Ariyaratne, Sri Lanka Journal of Physics Vol. 3 (2002) 77-88
  17. Forecasting the occurrence of rainfall in selected weather stations in the wet and dry zones of Sri Lanka, H.K.W.I. Perera, D.U.J. Sonnadara and D.R. Jayewardene, Sri Lanka Journal of Physics Vol. 3 (2002), 39-53
  18. Measurements of lightning peak currents in the first return stroke of negative cloud to ground flashes, AB Weerasekara, DUJ Sonnadara, IMK Fernando, R Lelwala and TR Ariyaratne, Singapore Journal of Physics, Vol. 17, No. 1, 2001, 37-45, (published in 2003)
  19. The fine structure of Positive lightning return stroke radiation fields, V Cooray, M. Fernando, C Gomes, T Sorensson, IEEE Transactions on Electromagnetic Compatibility, Vol. 46, No.1 February 2004
  20. Characteristics of chaotic pulse trains generated by lightning flashes, C. Gomes, V. Cooray, R. Montano and U. Sonnadara, Atmos. Phys. Solar Terres. Phys
  21. Correlation between current waveforms of electrical discharges generated by a cable generator and optical signatures for several selected wavelengths, P. Liyanage, V. cooray (Accepted for ICLP 2004)
  22. Further measurements on long impulse current associated with positive return strokes, U. Sonnadara, V Cooray, R Montano, CM Edirisignghe, P Liyanage, (Accepted for ICLP 2004)
  23. Optical signatures of laboratory sparks with currents comparable to return strokes in lightning flashes, P Liyanage, R Monatano, V Cooray (Accepted for ICLP 2004)
  24. A study of several time resolved lines in a laser triggered plasma, P Liyanage, M Rahman, V Cooray (Accepted for ICLP 2004)
  25. Frequency spectrum of electromagnetic fields of positive return stroke, S Sharma, M Fernando, V Cooray (Accepted for ICLP 2004)

Postgraduate Thesis Publications

  • Ph.D. Thesis
  1. On fair-weather and Thunderstorm Electricity – Basis for Construction of an Atmospheric Electrical Station in Sri Lanka, K.P.S. C. Jayaratne, PhD Thesis, University of Colombo, Sri Lanka, February 1992
  2. On the Nature of Lightning Flash: With special attention to the initiation, modeling and remote sensing of return stroke, PhD Thesis, C. Gomes, PhD Thesis, University of Colombo, July 1999
  3. Studies on the Basic Atmospheric Electrical Parameters of Fair-Weather and Related Processes in the Electrode Layer, R. Lelwala, PhD thesis, University of Colombo, Sri Lanka, June 2001
  4. Measurements and Analyses of Fast Transient Electromagnetic Field Generated by Ground and Cloud Flashes with Special Attention to Lightning Direction Finding, I.M.K. Fernando, PhD Thesis, University of Colombo, June-2001
  • M.Phil. Thesis
  1. Characteristics of Cloud-to-Ground Lightning Flashes Observed with a Wideband Magnetic Direction Finding System, A. B. Weerasekara, MPhil Thesis, University of Colombo, Sri Lanka, August 2001
  2. Exploring the spatial and temporal variation of rainfall in Sri Lanka, HKWI Jayawardane, MPhil Thesis, University of Colombo