Facing the challenge of lightning related incidents:

National Centre for Lightning Safety in the offing

By Ranil WIJAYAPALA

The danger of lightning once again came to light last week when three people from the same family became lightning victims incident in Amithirigala Avissawella and another death at Baduraliya, Mathugama, making Sri Lanka becoming one of the worst hit by lightning incidents.

According to the Meteorological Department the number of deaths due to lightning incidents reached 51 in the year 2011 giving alarming signals about the situation and bringing the average number of deaths due to lightning incidents in Sri Lanka from 30 to 40 per year. In the year 1997, the number of deaths reported was 49 while 16 deaths of animals were also reported in that year.

This shows how this natural phenomenon has badly affected the the country despite continuous educational programs carried out by the relevant authorities including Meteorological Department and the Disaster Management Ministry to mitigate the damages caused by this natural phenomenon.

However, this natural phenomenon has become a frequent killer across the globe and according to the National Weather Service of the United States, lightning causes an average of 62 deaths and 300 injuries in the United States each year as it has become the number 2 Weather Killer in the U.S.

Therefore, Sri Lanka as a small island with only 65,000 square kilometres land stretch and with 2 million population, the average of 30 to 40 lightning related deaths is an alarming level.

Apart from this the economic losses due to this natural phenomenon has not been properly estimated as many of these incidents are not reported properly for any evaluation by relevant authorities.

According to G. B. Samarasinghe who retired as the Chief of Meteorology Department on March 23, the number of deaths and injuries due to lightning strikes may be much higher than the statistics gathered by the Met Department as many of these incidents are unreported.

He says lightning is a natural phenomenon and a disaster that cannot be stopped by any.

"What we always can do is to just record it. You can't confront it but can minimise the damages from it by taking precautionary action. Other than that, there is nothing available with us to fight the nature", he says sharing his ideas about the lightning related incidents in Sri Lanka in an interview with the Sunday Observer just after his retirement.

As far as lightning is concerned, it is a very natural phenomenon and when there is enough moisture and enough heating and the atmosphere is very unstable, clouds develop and extend to 30,000 feet and even 40,000 feet high.

Inside those clouds there are water droplets going up and down and with their movements within the cloud an electrical charge is formed and the minus charges you find at the bottom of the cloud and on the top you find positive charges.

Due to these charges there may be intra-cloud flashes and inter cloud flashes due to electrical discharges associated with the charged cumulonimbus clouds. "But the ground stroke is the worst and the most dangerous thing", explaining the way the lightning incidents occur, Samarasinghe added.

The ground flash, which is important as a hazardous event, is the electrical discharge between the negative charge centre of a cloud and the positive charge centre on the ground. Under certain conditions, positive ground flashes may occur between the positive charge centre of a cloud and the earth. "This discharge is the most dangerous in this natural phenomenon and that is what we have to avoid. The voltage difference between these is about 100 million volts. Just think about a 25 volt battery and take a wire and take it very close you find sparks flashing. Like that this flash comes down through the atmosphere. The atmosphere resistance is overcome by this very high energy so that we will have to be very careful to avoid it", he said.

"Nobody knows where it discharges. Sometimes may be there is an affinity. When these clouds come there should be some attractive things like metals for them to discharge this very high energy", he added.

According to Samarasinghe, in Sri Lanka the frequency of lightning incidents are very high during inter monsoon periods between the two main Monsoon periods the South West monsoon period from May to September and North East Monsoon from December to February.

"Therefore, the lightning strike may occur during the first Inter Monsoon period of the year from March to April and the second Inter Monsoon Period from October to November ", he added.

During these Inter Monsoon periods there is no strong winds and when there is no strong wind very tall clouds develop. Those clouds get higher and higher and potential is very high for lightning. " That is one reason for Inter Monsoon periods are more conducive for lightning activities", he added.

Apart from these periods we get thunder storms during other wind regimes like the South West monsoon and the North West monsoon when there are disturbances like cyclones depressions, low pressure areas.

"During the North West Monsoon we get disturbances from the Bay of Bengal and even with that we get thundery activities. But it is for a very short period", he said.

Samarasinghe says that the latest report by the Inter Governmental Panel for Climate Change has mentioned that convective activities are on the increase and also creasing lightning activities are on the increase due to climate change. "Climatic changing we are not sure this change is for ever or it is a transition period. Sometimes when things happen, I always say that this might be something a transition period", he added. Samarasinghe also says that in Sri Lanka, the Met Department has identified, Horana, Ratnapura and Avissawella areas where we get large number of lightning incidents.

"One reason is that there is more rain in these areas. Rain is due to the cloud development and cloud is again with the inter monsoon and convective type of rain lightning is essentially with them", he added.

Apart from this, pockets like Kegalle, Medirigiriya, Polonnaruwa and sometimes Hambantota have also reported lightning incidents.

You still get the lightning incidents from places like Polonnaruwa. Sometimes in Medirigiriya, sometimes in Hambantota.

Referring to the allegations that the increased development activities and the increase number of Telecom towers and the high rise building also become a factor for the increase in occurrences of lightning, Samarasinghe said that, they are inviting factors for lightning.

"But when these high rise objects are there, we should take precautionary action by having very good earthing systems and they have to be checked on a regular basis, whether these earthing systems are in order", he added

"What happens is, we do establish a proper earthing system and we forget it. It is the case. We should check it monthly, once in three months or by annually to check whether there is any resistivity. If there is no resistivity it grounds smoothly.

That is the problem. When it is not grounded properly it goes around. It goes to other directions", he added.

"I personally believe that these communication towers should be away from the habitats", he added.

According to Samarasinghe, in the near future the Telecommunication Regulatory Commission is also considering to have fibre optic mechanisms where you don't need high rise towers. They don't need towers and repeaters and even the house top can accommodate that tower. That is one technology we need. Some telecommunication system providers in Sri Lanka are already having this system.

But the way, since the lightning related incidents are getting increased there should be systems to mitigate those damages.

"Last year we had 51 deaths relating to lightning. In year 2002 we had 49 cases. We can say an average of 30 to 40 deaths per year. So this is a problem that we have to address very soon", he added.

Nobody complains about the equipment damage. Dr. Chandana Jayaratne and his students through a survey has estimated that lightning related incidents cause Rs.300 million to Rs.1 billion damages to properties. That means there is a burning problem and that is a national issue", he added.

That is why in February 2011, Disaster Management Minister appointed a committee with the Chairmanship of the Director General of Meteorology to look into this situation. "At that time we started the process, and we got all the key personnel in the country, the experts in the subject, professors from the Moratuwa University. Dr. Chandana Jayaratna, Telecommunication Regulatory Commission, representatives from the health sector and all other sectors relevant to the subject", he added.

"We were just contemplating an idea when we are giving an electricity connection the CEB should think of making it compulsory to have lightning protection system. There are search protectors and search diverts that has to be a part of the total package once the electricity supply is given, may be government affording a part of the cost", he added.

The committee has recommended to establish a National Centre for Lightning Safety and the Cabinet paper in this regard has already been formulated to establish a regulatory mechanism for lightning related incidents and to have a proper data base to record all lightening related incidents enabling the country to face this challenge effectively and mitigate damages.