Bediding Phenomenon During Dry Season Makes Air Feel Colder, IPB Explains

During Indonesia's dry season, residents may notice a distinct chill in the air during the night and early morning hours. This phenomenon, known as 'bediding,' is a natural atmospheric event explained by Dr. Givo Alsepan, a lecturer at IPB University's Department of Geophysics and Meteorology.

Alsepan clarified that bediding is not a direct consequence of climate change but rather a normal part of seasonal climate dynamics, typically occurring between June and September. It manifests as a significant drop in daily minimum temperatures, driven by highly effective radiative cooling.

The process is amplified by several factors common during the dry season. Clear night skies allow the heat absorbed by the Earth's surface during the day to radiate efficiently back into space. Furthermore, the air is generally drier than during the wet season, meaning less water vapor is present to trap heat. This drier atmosphere facilitates more effective cooling.

This effect is often more pronounced in mountainous and highland areas due to higher elevations and the tendency for cold air to pool in valleys. In regions like the Dieng Plateau, bediding can even lead to frost formation. The phenomenon is further strengthened by the Australian monsoon, which brings cooler, drier air masses towards Indonesia, particularly affecting areas south of the equator like Java, Bali, and Nusa Tenggara.