Why Does Rain Fall During the Dry Season?

The pace of global warming over the last decade shows a worrying trend, with the rate of increase nearly double that of the 1970s era. Currently, the Earth’s temperature has risen by 0.35 degrees Celsius, a figure that triggers a surge in the intensity of extreme weather across various parts of the world. Climate experts from Universitas Gadjah Mada (UGM) warn that this phenomenon is not merely a rise in numbers but a real threat to the sustainability of lowlands to the national food sector. Dr. Emilya Nurjani, a climate expert from UGM’s Faculty of Geography, explains that this temperature increase triggers the melting of ice in the North Pole, leading to a rise in sea levels, thus threatening the existence of lowlands. Not only that, high temperatures accelerate the evaporation process. When sea surface temperatures warm, the potential for hydrometeorological disasters such as tropical cyclones increases sharply. “If air temperatures rise higher, causing sea surface temperatures to rise further, another form is cyclones that will occur more frequently. If cyclones happen often, the subsequent impacts are floods, then for example strong winds, and also other height changes,” Emilya explains, quoted from the UGM website. Global warming triggered by human activities, such as the use of fossil fuels, increases concentrations of greenhouse gases. As a result, more solar radiation is absorbed by the Earth than reflected back. This phenomenon not only brings flood disasters but also strong winds capable of uprooting trees and damaging residents’ infrastructure. The most worrying impact targets food security. Rising temperatures cause the dry season to arrive earlier with drier conditions. “Because if the dry season is prolonged, it will impact the agricultural sector. Farmers will struggle to plant rice, especially in the third planting pattern,” she adds. Rising temperatures also affect evaporation and transpiration processes. On one hand, abundant water vapour in the troposphere can accelerate the formation of rain clouds that trigger puddling. However, during the dry season, the Australian Monsoon phenomenon occurs. High pressure in Asia causes water vapour from the south to merely “pass through” Indonesia towards the north. “The cloud formation process during the dry season decreases, so we experience the dry season,” Emilya reveals. In addition to rainwater storage, she emphasises the importance of prudence in using groundwater, whose reserves heavily depend on rainwater input. “So water is used according to its function. For example, for domestic water needs, we can use groundwater, but for other needs, we can use surface water or other types of water,” Emilya concludes. These mitigation steps are deemed urgent to prevent the rate of temperature rise from continuing and triggering more permanent environmental damage for future generations.