Jakarta – The city administration resumed on Sunday its weather modification operation (OMC) until Feb. 6 in an attempt to reduce rainfall intensity during extreme weather conditions.
On Sunday, a joint operation involving the Jakarta Disaster Mitigation Agency (BPBD Jakarta) and the Meteorology, Climatology and Geophysics Agency (BMKG), with the support of the Air Force, released several tonnes of salt, or sodium chloride (NaCl), into the sky.
"The OMC this time is supported by the Air Force, which deployed a Casa 212-200 aircraft to disperse NaCl in Jakarta's sky," Mohamad Yohan, head of BPBD Jakarta's information data center, said on Monday, as quoted by Tempo.co.
BMKG head Dwikorita Karnawati told a virtual press conference last Saturday that the operation aimed to reduce rainfall intensity from heavy to moderate.
The OMC worked by targeting rapidly developing clouds with a potential for heavy to extreme rainfall, said Dwikorita, while nothing that attempting to modify weather during the peak of the rainy season was challenging due to rapid and massive cloud formation.
The January-February period marks the peak of the rainy season. This year's rainy season is influenced by a stronger Asian monsoon wind system due to a weak La Nina, with the condition expected to last until March or April.
Acting Jakarta governor Teguh Setyabudi has instructed the city administration to prepare for the potential return of heavy rains that could lead to flooding, especially in areas prone to the natural disaster.
Nearly 3,000 people were evacuated from their homes after heavy overnight rains last Tuesday caused a series of floods across the capital. Local weather stations recorded extreme rainfall levels of up to 184 millimeters per day.
Jakarta authorities previously deployed a weather modification in December, which they said resulted in a 38 percent decline in rainfall intensity.
Data from GSMap (Global Satellite Mapping of Precipitation) showed that rainfall in the city during the previous OMC from Dec. 25 to 31 ranged from zero to 40 mm per day, peaking at 40 mm on Dec. 25.