PETALING JAYA: A total of 60 cloud-seeding flights had been carried out nationwide as of Monday to address dry weather and the effects of haze.
Malaysian Meteorological Department (MetMalaysia) director-general Dr Mohd Hisham Mohd Anip said cloud-seeding operations were conducted based on current needs and suitable atmospheric conditions.
The operations aimed to increase rainfall in targeted areas, particularly to address rainfall shortages, support water resource management and mitigate the effects of haze.
"MetMalaysia determines the suitability and timing of operations based on continuous analysis and monitoring.
"Among the key factors assessed are the presence of clouds capable of producing rain, atmospheric moisture content, wind direction and speed, atmospheric stability, and the movement of weather systems," he said.
Hisham said the assessment also took into account meteorological observation data, weather forecast models, the movement of weather systems and rainfall potential in targeted areas.
"For areas experiencing rainfall shortages or affected by haze, the assessment also considers local weather conditions, air mass movements and rainfall potential in the targeted areas," he said.
More than 90 per cent success rate in inducing rain
On the effectiveness of cloud seeding, he said the operations had recorded a success rate of more than 90 per cent in producing rain in targeted areas.
The success rate referred to the operations' ability to induce rainfall, rather than an increase in the amount of rainfall recorded.
"Effectiveness is assessed based on rainfall recorded in targeted areas after operations and data from the meteorological observation station network.
"However, it is important to understand that rain recorded after an operation is not necessarily caused entirely by cloud seeding, as rainfall can also occur naturally," he said.
Forest fires in Kalimantan affect an area more than half the size of Perlis
Meanwhile, forest fires in Kalimantan, Indonesia, have affected about 57,081 hectares, or 570.81 square kilometres, an area equivalent to more than half the size of Perlis.
Perlis, Malaysia's smallest state, covers an area of 819 sq km.
Environmental and occupational health expert Professor Dr Haliza Abdul Rahman said West Kalimantan accounted for 38,310 hectares, or 67.1 per cent, of the total area affected by fires reported as of yesterday.
"Based on the latest data from Indonesia's Forestry Ministry's Sipongi system and the National Disaster Management Agency (BNPB), West Kalimantan accounted for about 38,310 hectares, or 67.1 per cent, of the total area affected by reported fires.
"Central Kalimantan recorded about 7,634 hectares, followed by South Kalimantan with 3,387 hectares and East Kalimantan with about 1,288 hectares," she said.
Haliza said that although the fires affected only 0.106 per cent of Kalimantan's total geographical area, their environmental impact was significant for several reasons.
"Burning peatland can produce larger amounts of smoke that linger for longer because fires can spread beneath the ground, making them difficult to extinguish completely.
"Smoke from these open fires can also be carried across borders, including into Malaysia and Singapore, depending on wind direction and speed, as well as prevailing atmospheric conditions," she said.
Haliza said this was one reason Air Pollutant Index (API) readings frequently fluctuated between areas, particularly when winds carried smoke from fire sites towards populated areas.
"Besides affecting air quality, forest and peatland fires also release carbon dioxide and other pollutants into the atmosphere, contributing to climate change and threatening the balance of ecosystems," she said.
Meanwhile, climatologist and climate change expert Prof Dr Fredolin Tangang said hot and dry conditions were expected to persist in Kalimantan and Sumatra, increasing the risk of forest fires in those areas.
"The same weather conditions could also trigger fires locally if hot and dry conditions persist.
"In Malaysia, hot and dry weather, particularly in Sabah and northern Peninsular Malaysia, is expected to continue until early next year," he said.
Fredolin said weather and climate patterns associated with the El Niño phenomenon warranted close attention, as the conditions could increase the risk of fires and affect air quality.
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