Doppler radar near Pamban

The entire east coast will soon be covered by meteorological mapping, as a state-of-the-art weather station, complete with a Doppler Weather Radar (DWR), will soon be installed close to Pamban near Rameswaram in Ramanathapuram district. Currently, DWRs are available in Kolkata, Paradeep, Visakhapatnam, Machilipatnam, Chennai and Karaikal. “Continuous monitoring of weather is now possible at Ramanathapuram,” said YEA Raj, deputy director general, Regional Meteorological Centre (RMC), Chennai. Last week, the department formally took over eight acres at Pamban from the state government at a nominal price. The 24-hour DWR will provide a near accurate picture of impending rainfall and cyclones. The mechanism of a radar is basic science. Radars (Radio Deduction and ranging) emit radio signals, which are transmitted to the atmosphere. Rain-bearing clouds are either ice or water particles, and when the radio signals encounter them, they are reflected back to the station.Unlike in the past when analog radars could track rain-bearing clouds only three times a day, and data crunching was a laborious exercise requiring shutting down of the radar, the new DWR will work uninterrupted, provide there is continuous power supply. “The data will be uploaded every 10 minutes and users anywhere can log on to the website for current information,” said S B Thampi, director, DWR, Chennai. The upgraded technology will help in dissemination of crucial information to farmers and fishermen in the locality. Ramanathapuram receives 85 cm of rainfall annually, while Pamban, where the DWR will be located, receives nearly 100 cm. The DWR will continuously monitor the cloud formation on land and over the sea area within a 100-km radius, since rain-bearing north-east monsoon clouds are visible at a three to four kilometre distance in the atmosphere. South-west monsoon cloud formation can be tracked by the DWR even at a six km distance, while cyclonic clouds can be tracked even at a 15 km distance in the atmosphere, said Raj. The new DWR and office complex will replace the existing weather station at Pamban which is nearly 100 years old. Work on the 30-metre (100 feet) tall office will commence soon and the radar will be mounted atop the building. The radar has a 10-metre diameter and weighs 10 tonnes along with the antenna. Located 15 km north and west of Ramanathapuram at Pullangudi village, the station also hopes to introduce wind profilers at a later stage. “Within two years, the station will become functional,” said Raj about the Rs 20 crore project.