Now on Pune IMD website: How India weathered the last 117 yearshttps://indianexpress.com/article/cities/pune/now-on-pune-imd-website-how-india-weathered-the-last-century-5514568/

Now on Pune IMD website: How India weathered the last 117 years

While Daily Weather Reports from India, starting in 1901, have been digitised, daily weather charts available since 1932 till 2014 are also available in a digital format.

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The unusual rise and fall in temperature, however, could be attributed to cloudy weather, said an official of the Indian Meteorological Department, Chandigarh. (Representational image/Vignesh Krishnamoorthy)

It will now be possible to retrieve and trace past weather events that occurred over India, dating back to as early as 1901, thanks to a team of scientists at the India Meteorological Department (IMD) who have digitised over 8 lakh weather charts and thousands of daily weather reports issued for the country every day.

It took more than four years for G Krishnakumar, director of the National Data Centre in IMD, Pune, and his team, which comprises data experts and weather forecasters, to complete this massive exercise of making physical charts and reports available in a digital format.

These are now available on the website of IMD Pune.

“With time, preserving and handling of many of the charts was becoming difficult. Some of them were damaged and proving to be of little use. That’s when it was decided to prepare a digital catalogue of analysed weather charts , not only to preserve them but also to offer weather forecasters quick access to all past recorded weather events with just a click,” Krishnakumar told The Indian Express.

All kinds of weather information — based on synoptic events like cold wave, heatwave, fog, snow, thunderstorm, cyclonic storm, hail, rainfall and others from every sub-division (there are 36 sub-divisions in India) along with weather systems from both the Arabian Sea and the Bay of Bengal on any given day — has been made available online.

While Daily Weather Reports from India, starting in 1901, have been digitised, daily weather charts available since 1932 till 2014 are also available in a digital format. During the pilot phase of the project, about 25,000 charts were digitised, as the team attempted the daunting task of maintaining all the data plotted on the maps intact. The challenges included handling huge volumes of charts and reports, which required expert manpower and reliable software that could not only maintain a catalogue but also retrieve the desired information in the shortest possible time.

“The charts were photographed carefully, maintaining the actual size, so that neither the image quality nor the data was compromised. Some older charts even had data in Indian regional languages or scripts, which are no longer compatible. In order to extract all the data, we even sought the help of language experts,” said the NDC director.

In the current phase, the IMD group is working on a process called data rescue, which is aimed at filling the missing weather data. “In some cases, data sets are missing due to lack of information from a particular weather station, which could have either shifted out to a new location or was opened much later. For instance, IMD has older weather data sets from Colaba observatory in Mumbai, rather than data from Santacruz station,” said Krishnakumar.

In the coming months, a dedicated portal of Climate Data Services would be launched, which would have integrated weather data, gathered and maintained by other institutions operating under the Ministry of Earth Sciences. “In addition to surface and atmospheric weather parameters maintained by IMD, the portal would have ocean-related, satellite-based and other data, which will be collected from sister MoES institutes. It will help all stakeholders, including authorities from health, energy, power, water resource sectors, towards devising better policies and planning,” said Krishnakumar.

Another major challenge, said the senior scientist, was maintaining and verifying data in case of extreme weather events. To address this problem, experts have devised a special software which records weather parameters like temperatures, humidity, rainfall and wind speed, among others, at an interval of 10 minutes.

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“…This software has been under testing at five weather stations for three years. It will mainly serve urban city planners and authorities in the administration, who often need to plan rescue or contingency plans during extreme weather events within a short span of time,” he said.