Weather Getting Hotter, IPB University Meteorology Lecturer Reveals the Cause

Recently, people in a number of regions in Indonesia have complained about the air temperature feeling hotter. This phenomenon raises questions about the cause behind the increase in temperature and its impact on daily activities and environmental conditions.

According to Sonni Setiawan, SS, MSi, a lecturer at the Department of Geophysics and Meteorology at IPB University, this phenomenon is related to the absorption of electromagnetic radiation by the atmosphere. This directly affects changes in air temperature, particularly in the lower troposphere.

“The atmosphere functions as a medium that receives radiation from two main sources, namely the sun and the earth. Radiation from the sun is called shortwave radiation, while radiation from the earth is called longwave radiation. Both have different absorption spectra,” he explained.

He added that solar radiation is absorbed more in the stratosphere to thermosphere layers, especially in the ultraviolet (UV) spectrum. Meanwhile, long-wave radiation from the Earth’s surface is more dominantly absorbed in the troposphere layer in the infrared (IR) spectrum.

Furthermore, the amount of radiation energy absorbed by the atmosphere is highly dependent on the density of absorbing particles and the intensity of radiation received. “The higher the concentration of absorbing particles, the greater the energy absorbed, causing the air temperature to rise,” he said.

According to him, there are two main factors that trigger air warming in the lower atmosphere. First, an increase in the concentration of long-wave radiation-absorbing gases such as water vapor, carbon dioxide (CO₂), and aerosol particles from pollutants and dust. This process is known as the greenhouse effect, which causes heat from the earth to be trapped in the atmosphere.

Second, changes in land cover due to the conversion of green areas into built-up areas also affect the heat capacity of the Earth’s surface. Surfaces with low heat capacity, such as concrete or asphalt, absorb and emit heat faster than soil or vegetation.

“This causes the surface temperature to increase and intensifies warming in the lower atmosphere,” he said.

In addition to these factors, the Earth’s astronomical position also affects the variation in radiation received. In October, the sun is almost directly above Java and Bali, so these two regions receive higher levels of solar radiation.

“This phenomenon is a natural physical process that occurs every year. However, the increase in temperature will feel more extreme when influenced by changes in land use and increased pollutants in the atmosphere,” he concluded. (AS) (IAAS/NRA)