Mumbai gets a Doppler radar

A week after it arrived from China, the long-awaited Doppler Radar will reach the Colaba office of the Indian Meteorological Department (IMD) Thursday morning. The dish-shaped antenna itself weighs ten tonnes, and is so big that traffic police have advised the weather bureau to transport it in the early hours of the morning when traffic is sparse. Once it has been assembled and installed by a team of Chinese experts that will arrive especially for the task, the new marvel will appear like a giant white football in the sky. However, demolishing the myth that was created about its efficacy in the aftermath of the 26/7 floods, met officials point out that the Doppler radar is no magic wand that will spew miraculously accurate forecasts. The previous cyclone warning radar is obsolete they say, so this is simply a case of new technology replacing the old. “The Doppler radar is a monitoring device, not a forecasting one. It is simply a tool of modern technology that allows you to measure the velocity of wind and detects cloud movement and speed apart from droplet formation. Like X-rays and MRIs help a doctor diagnose the problem but are not means of treating the disease,’’ says R V Sharma, deputy director general of the Indian Meteorological Department (IMD), Mumbai. Fiftyfive such radars, each costing roughly Rs 10 crore, will be installed nationwide. Mumbai has received the first of the lot, a process “expedited’’ by 26/7. The weathermen have been busy in the interim. One of the prerequisites for installing the Doppler radar was the availability of a high, secure location undisturbed by highrises in the surrounding area for these would interfere with data collection from the atmosphere. Officials scoured several sites like the World Trade Centre, Oberoi Hotel, Wadala, Chembur and Aarey milk colony before settling on the very structure in Navy Nagar that housed the existing cyclone detection radar, “about one km from our Colaba headquarters,’’ says Sharma. However, this apartment building that is owned by the Navy has been amply strengthened to enable it to host the bigsized, heavy radar that weighs nearly 15 tonnes. “Architects were employed to increase the width of the structure from around 10 metres to 15 metres by preparing a cantilever projection,’’ says Sharma. Of course the met department picked up the tab. The global recession swept this project off course too, for crucial parts required for assembly were not being manufactured as readily. That hurdle has now been overcome. “We will run a test drive for about two weeks before commissioning the device,’’ says the met chief. “Hopefully, we will complete the task before the onset of the monsoon.’’