Transboundary haze in Singapore could already be quite a headache for us when going about our daily activities. But what if natural phenomena could prolong the upcoming haze episode? Here, we will introduce two climatic phenomena that could aggravate SG transboundary haze– El-Nino and Indian Ocean Dipole.
El-Nino is part of a climatic phenomenon called ENSO (El-Nino Southern Oscillation) and it involves the abnormal warming of surface water over the Pacific Ocean. Under normal conditions, trade winds will blow the warm surface waters from South America towards Indonesia. This causes Southeast Asia to experience wetter climates. However, in the case of an El-Nino event, trade winds will weaken or even reverse, causing an accumulation of warm waters along the coast of South America instead. This may culminate in a drier climate in Southeast Asia. Lower precipitation rates will increase the chances of droughts and higher temperatures– creating the perfect ‘storm’ for peatland fires. If these peatland fires occur in areas within close proximity of Singapore, then there is a higher chance of southeasterly to southwesterly monsoon winds of blowing haze over. The World Meteorological Station has predicted a 90% chance of an El-Nino event in the second half of the year, insinuating the possibility of hotspot activities in parts of Southeast Asia.
Another lesser known climatic phenomenon called the Indian Ocean Dipole (IOD) could also intensify the period of dry season experienced in Southeast Asia. In a positive IOD event that could occur in the coming months, cloud formation over the Indian Ocean could be reduced, resulting in drier and warmer conditions to Southeast Asia. It is important that we are aware of these natural phenomena so that we will not misunderstand the causes of haze. In the case of a severe haze episode in Singapore, we should better prepare ourselves by wearing N95 masks and having functional air purifiers at home.