CHENNAI: As the ageing S-band radar at Chennai Port is set to be replaced soon Chennai city and the neighbouring districts will get three new Doppler weather radars to improve rainfall forecast accuracy, especially over north interior Tamil Nadu, officials said.
“We will have three X-band radars, but their locations will be away from Chennai because we want the setup to form a triangle. This will help us focus more on neighbouring Tiruvallur, Kancheepuram and Chengalpet districts,” M Ravichandran, secretary, ministry of earth sciences said recently.
The city has an S-band radar operational at Chennai Port since 2002. With a 500km range, it is mainly used for tracking cyclones approaching the coast and monitoring clouds. In contrast, the X-band radar installed at NIOT campus in Pallikaranai, with a 100km–150km range, helps track rainfall and issue nowcasts for city.
“We are finalising locations for the new radars. In the next few years, the country will have a network of 100 to 120 radars, ensuring that no rain activity goes unnoticed,” he added.
He also inaugurated an urban testbed facility at Sathyabama Institute of Science and Technology as part of Mission Mausam, aimed at studying the city’s urban climate variability. The facility includes instruments such as a sound detection and ranging system to measure wind profiles up to 4km and turbulence intensity, a ceilometer with depolarisation capability to study clouds and aerosols, and a micro rain radar. “This testbed will help us better observe local weather changes,” he added.
Tamil Nadu has been witnessing a series of extreme weather events during monsoon seasons, and forecast has become a challenge because of lack of good radar coverage across the state.
Also, there were instances in the past, especially during 2022 rains, when Chennai’s S-band radar went defunct, X-band radar in National Institute of Ocean Technology (NIOT) was not fully calibrated, and Sriharikota radar was stretched to its full capacity making it difficult for the meteorologists to pick up rain bands that hit Chennai by surprise.
