With the arrival of the northeast monsoon two months away, the state government has floated a tender to install two Doppler weather radars each at Yercaud and Ramanathapuram to monitor the storms. These two instruments will cover areas beyond the coverage of two radars currently installed at Chennai and one radar each at Karaikal and Sriharikota.
According to the Tamil Nadu Disaster Risk Reduction Agency’s tender, the contracted company has to supply, install, test, commission and maintain two C-band dual polarized solid state amplifier based Doppler weather radars. Both Yercaud and Ramanathapuram are the temporary locations selected for installation of the equipment.
A weather radar transmits electromagnetic waves and measures the energy scattered by liquid or solid water particles in the atmosphere. The distance the waves can reach is the reflectivity of the radar. The radar, which will be installed at two locations, will have radar reflectivity or rain detection capability up to 450 km. Radars are mainly used to monitor low latitude weather disturbances such as low pressure, depressions and cyclones. Tamil Nadu receives more than 47% of its annual rainfall of 94 cm during the northeast monsoon. .
At an event earlier this year, India Meteorological Department Director General Mrityunjay Mohapatra said that the two radars to be installed by the state government will cover the southern parts of the state. Currently, Chennai The city comes under two radars—one S-band radar at the port and one X-band radar at the NIOD campus—and two S-band radars, one each, at Karaikal and Sriharikota. Although the radars at Kochi and Trivandrum cover parts of Tamil Nadu, there are still some areas in the state that are not covered by the radar network.
The two new radars will cover the southern and northern interior districts of Tamil Nadu, officials of the India Meteorological Department said, which are out of range of the existing radars on the east coast. While S-band radars cover a radius of 500 km, X-band covers a radius of 150 km.
”We want to bring more places under the radar. At present there is not much coverage in areas south of Karaikal. If it is in Ramanathapuram, it will include southern districts and one in Yercaud, northern inner districts,” said Senthamaraik Kannan, director of the Chennai Meteorological Research Centre.
