NEA scotches rumour of cloud seeding for F1 weekend
Workers setting up for the Formula 1 Singapore Grand Prix at Marina Bay on Sept 16, 2015. Photo: Ooi Boon Keong/TODAY
SINGAPORE — Debunking a rumour that the authorities are doing cloud seeding to reduce the impact of the haze on the Formula One race this weekend, the National Environment Agency has said no cloud seeding by the Singapore Government has been done, nor are there plans to carry it out.
The rumour is untrue, said the NEA and Minister for the Environment and Water Resources Vivian Balakrishnan. “Singapore is so small that even if anybody tried to do it, the rain would almost certainly fall outside Singapore. Singaporeans should beware of malicious people spreading false rumours during a period when anxieties are heightened,” wrote Dr Balakrishnan on Facebook today (Sept 17) as the 24-hour Pollutant Standards Index (PSI) shifted into the moderate range.
At 11pm today, the 24-hour PSI was 69 to 79 and the PM2.5 level was 36 to 47 microgrammes per cubic metre, an improvement over previous days when air quality hovered largely in the unhealthy range. The improvement was due to prevailing winds blowing from the south-east.
The NEA said in an update at 6pm today that the haze has been reduced over central and southern Sumatra, but some haze from Kalimantan has spread westward to the South China Sea east of Singapore.
The 24-hour PSI for tomorrow is likely to be moderate to unhealthy. The prevailing winds today are expected to blow from the east or south-east and occasional hazy conditions can be expected if there is unfavourable wind, said the agency.
Earlier this week, haze from Sumatra was blown in by winds from the south and south-west because of a tropical storm in the South China Sea that shifted wind direction.
On its website, the NEA said there is no reliable way to assess if cloud seeding — which requires the existence of suitable clouds for seeding — is effective for Singapore. “The small size of Singapore and the variability of winds also mean that the induced rain, if any, may not fall directly over our island,” it said.
The NEA also tackled an observation by some members of the public that the PSI does not reflect low visibility and a burning smell during certain periods of time. The measurements of six pollutants — particulate matter (PM10), fine particulate matter (PM2.5), sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide — determine the PSI, it said. When there is a burnt smell in the air, the six pollutants may not be the cause, said the NEA, which also monitors other parameters that affect air quality. At a media briefing on Tuesday, the authorities said visibility could be affected by humidity.
