PETALING JAYA: The country would see a higher reading of the Air Pollutant Index (API) due to transboundary haze from neighbouring Indonesia until Oct 4, warned climatologists.
This is due to the occurrence of El Nino and the positive Indian Ocean Dipole (+IOD) leading to drier weather than the past years, with experts warning that those who did not get to clear their land through open burning may do so with gusto this year.
Last Friday, a number of areas in the west coast of Peninsular Malaysia recorded unhealthy API readings. However, the good news is that local weather influences such as changes in the winds and occasional rain can lower the APIs in Malaysia.
Climate expert Prof Datuk Dr Azizan Abu Samah said that despite the rains, for the next few days, Malaysians must brace themselves for the wind to keep blowing in new particulates from hotspots in Sumatra and Kalimantan, Indonesia.
“The rains will wash the particulates away, but the source is still there and the wind will blow in new particulates. It is predicted that the haze will continue until Oct 4 with some variation of concentration locally due to local influences.
“I consider haze a major disaster since you are subjecting millions of Indonesians and Malaysians to unhealthy air pollution and it is done by humans lighting the fire. This is not an accidental forest fire,” stated the climatologist.“This year’s pattern is similar to 2019’s. Sumatra in now drier due the influence of El Nino and also positive Indian Ocean Dipole (IOD). So expect continued burning from Sumatra,” said Azizan.
However, he said that the situation can change if there is rainfall over Sumatra to douse the fire or if the Northeast Monsoon kicks in by late October.
“Those who have respiratory and cardiovascular comorbidity, especially elderly and young children, have to be careful to try to stay indoor and cut down outdoor activities as the smallest of the particulates which have travelled far can enter the lungs.
“For the past two years, because of La Nina, there were those who could not clear their lands by fire due to wetter conditions then. Now with El Nino and +IOD the condition in Sumatra is drier so all those delayed clearance will be done with a vengeance,” he added.Academy of Sciences Malaysia Fellow Dr Fredolin Tangang stated that the El Nino is currently active, strengthening and could be either in moderate and strong category. “If it follows the evolution or progression of a typical El Nino event, this region, including Malaysia and Indonesia, would continue to feel its impact until next April or May. At the same time, a +IOD is also developing.
“Based on my research and group members at Universiti Kebangsaan Malaysia, during September to November, Sumatra and Kalimantan would experience anomalous drier conditions during the El Nino event.
“This condition can be compounded by this +IOD, which makes the dry condition even worse due to the effect of El Nino alone. This dry condition can trigger forest fires and transboundary haze,” said the former UKM chair of the Department of Earth Sciences and Environment.
“The transboundary haze can be worse if it happens during the southwest monsoon because the prevailing wind is blowing from the south bringing the smoke to Malaysia. However, from the middle of September, as announced by MetMalaysia, we are already in the inter-monsoon period.“The typical weather condition during this period is that the wind is in variable direction and typically, we have thunderstorms in the afternoon and evening, especially in Peninsular Malaysia.
“Weaker winds blowing from the south, especially Sumatra and Kalimantan, may lessen the likelihood of really bad transboundary haze. But weather can be difficult to predict, the wind pattern can still be blowing from the south even though we are already in the inter-monsoon period and the smoke can still affect us,” said Fredolin.
In addition, the climatologist warned that if we have typhoons in the Philippines and South China Sea in the next few weeks, it will cause the air masses to flow north to our country from Sumatra and Kalimantan.
“This can increase the likelihood of transboundary haze. Currently, we have a tropical depression east of the Philippines and this causes the winds to blow from Sumatra towards Peninsular Malaysia and Singapore and advecting the smoke.
“Beyond November, the likelihood of transboundary haze from Sumatra and Kalimantan diminishes as first Kalimantan and Sumatra would experience a positive rainfall anomaly (plenty of rainfall) during an El Nino year and the wind direction is also from the north.
“No issue for us. But from December to March next year, Sabah and northern Sarawak would typically get much drier conditions during El Nino. Local forest fires may occur as we have large areas of peat soil in Sabah and northern Sarawak. If we have haze then, it would be due to local sources,” said Fredolin.
