Atmospheric Physics and Lightning IPPS SRI:01/1 Address Department of Physics University of Colombo 00 300 Colombo 3 Sri Lanka Visiting address Cumarathunga Munidasa Mawatha Phone +94-11-2584777, +94-11-2652762 (Private) Fax +94-1-2 584777 E-mail [email protected] Group leaders Dr. I. M. K. Fernando Staff members Dr. I.M.K. Fernando, PhD, Senior Lecturer Dr. R.Lelwala, PhD, Senior Lecturer Dr. G.A.C. Gomes, PhD, Senior Lecturer Dr. K.P.S. C. Jayaratne, PhD, Senior Lecturer Prof. T.R. Ariyaratne, PhD, Professor Prof. D.U.J. Sonnadara, PhD, Professor Dr. C.M. Edirisinghe, PhD, Senior Lecturer Dr. P. Liyanage, PhD, Senior Lecturer Dr J. A. P. Bodhika, PhD, Senior Lecturer Ms H.K.W.I. Jayawardane, MPhil, Research Assistant Mr V. Jeyanthiran, BSc, Probationary Lecturer Mr C. Perera, BSc, Research Assistant Mr P. Hettiarachchi, BSc, Probationary Lecturer Ms M. Hettiarachchi, BSc, Temporary Lecturer Summary Even though the two third of lighting activities in the earth takes place in the tropics, only a very few studies on lightning physics have been conducted in this region. The Atmospheric Physics and Lightning Research group was established in early 1970s with the aim of studying the physics of lightning and atmospheric physics in the tropics. In order to understand the lightning initiation and propagation of lightning ground and cloud flashes the group conducted a few studies. Thunder signatures generated by ground and cloud flashes were analyzed to understand the location of thunder sources in a lightning ground flashes. Also the frequency spectra and the variation of frequency and amplitude thunder signatures were studied. Still and video photographs were used to study the propagation of lightning channels. Lightning generated electric (radiation and static) fields together with high frequency signatures were collected in Florida, USA for further understanding of the lightning electric field signatures in subtropical regions. A new PhD program was started aiming to theoretical study on upper atmosphere lightning activities. Another PhD program has been initiated in the field of Electromagnetic Compatibility. According to the available information, the pollution level of Sri Lanka is increasing gradually. The rapid industrialization and the increasing number of automobiles are responsible for this increase. However, the effect on pollution on the environment due to highways and other industrial zones are not taken in to account in many cases. Therefore, the group decided to conduct a program to develop a dispersion model for Sri Lanka. The model is expected to give an understanding of the distribution of pollution by various sources in Sri Lanka. It is also expected to use the model for weather forecasting. Publications listed in the activity reports for year 2007 and 2008 include: - M. Rahman, V. Cooray, V.A. Rakov, M.A. Uman, P. Liyanage, B.A. DeCarlo, J. Jerauld, and R.C. Olsen III, “ Measurements of NOX Produced by Rocket-Triggered Lightning“, Geophysical Research Letters, 34, (2007) - J.S. Mäkelä, M. Edirisinghe, M. Fernando, R. Montaño and V. Cooray, “HF Radiation Emitted by Chaotic Leader Processes”, Journal of Atmospheric and Solar-Terrestrial Physics, 19(6), 707 (2007) - M. Fernando and V. Cooray, “Propagation Effects on the Electric Field Time Derivatives Generated by Return Strokes in Lightning Flashes”, Journal of Atmospheric and Solar-Terrestrial Physics, 69(12), 1388 (2007) - Research Highlights“A Flash of NOx “, Nature, 446, 4 (2007) - S.R. Sharma, V. Cooray and M. Fernando, “Isolated Breakdown Activity in Swedish Lightning”, Journal of Atmospheric and Solar-Terrestrial Physics, 70, (8-9), 1213 (2008) - S.R. Sharma, M. Fernando and V. Cooray, “Narrow Positive Bipolar Radiation from Lightning Observed in Sri Lanka”, Journal of Atmospheric and Solar-Terrestrial Physics, 70 (10), 1251 (2008) PhD Theses - Shriram Sharma, “Electromagnetic Fields Radiated by Lightning in Tropical and Temperate Regions” (2007) - CM Edirisinghe, “Behavior of Low Voltage Surge Protective Devices in Fast Transient and Repetitive Current Impulse Environment” (2007) - J. A. P. Bodhika, “A Study of Thunder Generated by Cloud and Ground Lightning Flashes” (2008) Conference reports and local/regional publications are not listed Major equipment Agilent Infinium 1GHz 4 Channel Oscilloscope Storage oscilloscopes (GOULD 4030 & LEADER, 40 MHz) ADVANTEST Spectrum analyzer (4 GHz max) LeCroy transient recorders (300 MHz, one with 4 Channels) Lightning flash counters (VO3 & V10 - older versions) Mackerras' Lightning flash counter ( CGR3 -latest version) Analogue to ASCII Converter (16 channel data acquisition system) Canon high speed photography camera with studio facilities Video cameras (01- Panasonic, 01-JVC) 21” Colour TV (SONY KV-2183GE ) Video Cassette Recorder (National NV-L28EO) Field mills (for electric field measurements) x-t flat-bed pen chart recorders (1 single & 2 dual, channels) x-y Chart recorder Obolensky filters- for space charge measurements Direction Finding stations with Electric and Magnetic field antennas Advanced Lightning Direction Finding System HP Laserjet printer with scanner and copier Cannon photocopy Machine Shaffner NGS 2050 Impulse Generator Monochromators (Edmond Industrial Optics) Weather stations Honda Generator Fridge (IGNIS- 2 door) Bruel and Kajar Microphone systems including an amplifier and a calibrator UMAX Powerlook 180 Film Scanner Research Visits and Training (in Europe) Participant Year Research host V. Cooray (10m)* 79/80 S. Lundqvist, Uppsala Univ. M. Edirisinghe (10m) 2003 V. Coorey, Uppsala Univ. M. Edirisinghe (4m) 2005 “ “ M. Edirisinghe (6m) 2006 “ “ I. M. K. Fernando (5 m) 94/95 V. Scuca, Uppsala Univ. I. M. K. Fernando (8 m) 95/96 V. Coorey, Uppsala Univ. I. M. K. Fernando (10m) 1997 V. Scuka/V. Coorey, Uppsala Univ.rsity I. M. K. Fernando (6m) 2000 V. Coorey, Uppsala Univ. I. M. K. Fernando (1.5m)** 2004 “ “ I. M. K. Fernando (2m) 2007 V. Coorey, Uppsala University (1m) and Univ. of Florida, USA (1m) I. M. K. Fernando (12m) 2008 V. Coorey, Uppsala University G. A. C. Gomes (13m) 95/96 V. Coorey, Uppsala Univ. G. A. C. Gomes (5m) 1997 V. Scuka/V. Coorey, Uppsala Univ. G. A. C. Gomes (12m) 1998 “ “ “ G. A. C. Gomes (2m) 1999 “ “ “ K. P. C. Jayaratne (3m) 84/85 V. Scuka/V. Coorey, Uppsala Univ. K. P. C. Jayaratne (12m) 86/87 “ “ “ K. P. C. Jayaratne (1m) 87/88 ICTP, Trieste, Italy K. P. C. Jayaratne (6m) 87/88 V. Scuka/V. Coorey, Uppsala Univ. K. P. C. Jayaratne (6m) 88/89 “ “ “ K. P. C. Jayaratne (7m) 89/90 “ “ “ K. P. C. Jayaratne (7m) 90/91 “ “ “ K. P. C. Jayaratne (2m) 91/92 “ “ “ K. P. C. Jayaratne (1m) 1994 V. Coorey, Uppsala Univ. K. P. C. Jayaratne (1m) 1996 “ “ Wasana Jayawardena (Ms) (4m) 2004 L. Enger, Uppsala Univ. Wasana Jayawardena (Ms) (5m) 2005 ” ” M. T. L. Kannangara (11.5m) 77/78 S. Lundqvist, Uppsala Univ. R. Lelwala (6m) 94/95 S. Israelsson, Uppsala Univ. R. Lelwala (9m) 95/96 ” ” R. Lelwala (3m) 1997 ” ” R. Lelwala (5 m) 1997 Prof. Tuomi Meteorology Inst., Finland R. Lelwala (7 m) 1998 S. Israelsson, Uppsala Univ. R. Lelwala (5 m) 2000 ” ” R. Lelwala (1.5m)** 2004 S. Israelsson, Uppsala Univ. J.P. Liyanage (4m) 2002 V. Coorey, Uppsala Univ. J.P. Liyanage (2.5m) 2003 “ “ J.P. Liyanage (4m) 2004 V. Coorey, Uppsala Univ. J.P. Liyanage (4m) 2005 V. Coorey, Uppsala Univ. (3m)and Univ. of Florida, USA (1m) G. Marasinghe (1.5m) 85/86 S. Israelsson, Uppsala Univ. S. Namasivayam (12m) 80/81 S. Israelsson, Uppsala Univ. S. Namasivayam (10m) 83/84 S. Israelsson/J. de Sousa Pires, Uppsala Univ. * Professor at Uppsala Univ. since 2000 * * Funds from Asia Development Bank Research Visits and Training (in Europe) continues Participant Year Research host S. Namasivayam (12m) 84/85 S. Israelsson, Uppsala Univ. S. Namasivayam (12m) 85/86 ” ” C. Perera (4m) 2006 V. Coorey, Uppsala Univ. C. G. K. Piyadasa (10m)*** 90/91 S. Israelsson, Uppsala Univ. S.R. Sharma (Nepal) (7m) 2006 V. Coorey, Uppsala Univ. R. Shrestha (Nepal) (3m) 2000 V. Coorey, Uppsala Univ. D.U.J. Sonnadara (1m) 2002 V. Coorey, Uppsala Univ. D.U.J. Sonnadara (9m) 2003 “ “ * * Funds from Asia Development Bank *** Now in group SRI:01/2 Highest Degree Obtained and Present Position Name and present position Degree Thesis Year Mr G. Vernon Cooray PhD “Remote Sensing of Lightning Return Strokes Through Prof. Uppsala Univ., Sweden 1982 the Electric Radiation Fields” Co-operation partner to the Thesis defended at Uppsala Univ. group Mr Sudalaimuthu PhD “Studies of Electromagnetic Fields from First and Namasivayam 1991 Subsequent Strokes of natural Lightning” Director Arthur C Clark Center Thesis defended at Uppsala Univ. for Modern Technologies, Moratuwa (now CEO, of a personal Electrical and Lightning protection company) Mr K P S C Jayaratne PhD “On Fair – Weather and Thunderstorm Electricity. Senior Lecturer, Group Member 1992 Basis for Construction of an Atmospheric Electrical Station in Sri Lanka” Thesis defended at Univ. of Colombo, Colombo, Sri Lanka Mr D. U. J. Sonnadera PhD “Electromagnetic Dissociation of Relativistic Si by Prof. Group Member 1992 Nucleon Emission” G. Marasinghe PhD “Effects of Substituting Silicon and Manganese for Iron Associate Professor of Physics, 1993 on the Magnetic Properties of Several Rare-Earth University of North Dakota Transition-Metal Boron Compounds Thesis defended at University of Missouri-Rolla Mr G A C Gomes PhD “On the Nature of Lightning Flashes: With Special Senior Lecturer, Group 1999 Attention to the Initiation, Modelling and Remote Member Sensing of Return Strokes” Thesis defended at Univ. of Colombo, Colombo, Sri Lanka Mr I M K Fernando PhD “Measurements and Analysis of Fast Transient Senior Lecturer, Group Leader 2001 Electromagnetic Fields generated by Ground and Cloud Flashes with Special Attention to Lightning Direction Finding” Thesis defended at Univ. of Colombo, Colombo, Sri Lanka Mr Ranjith Lelwala PhD “Studies on the Basic Atmospheric Electrical Senior Lecturer, Group Member 2001 Parameters of Fair-Weather and Related Processes in the Electrode Layer” Thesis defended at Univ.