India Meteorological Department (IMD) is stepping into its 150th year in 2024 and has planned yearlong events to commemorate the occasion across the country. The celebrations will kickstart on January 15. But interestingly, the weather observatory in Bengaluru pre-dates the IMD, which has its genesis in 1875.
“It started way back in November 1867 when the Central Observatory, for weather observation and forecast, was established at Bowring Hospital under Madras Presidency. The observatory only took three readings of temperature — at 10 a.m., 4 p.m., and 10. p.m. In 1894, observatories were established in Bengaluru, Mysuru, Hassan, and Chitradurga under the Mysore State Meteorological Department. In 1951, the office came within the ambit of the India Meteorological Department,” A. Prasad, Scientist, IMD, Bengaluru, recounting the history of IMD in Bengaluru.
“Thermometers used to be kept in a thatched shed back then. While in pre-independence times only surface air observation was being carried out, gradually, IMD Bengaluru started taking upper air observation with a balloon. The balloon used to be filled with hydrogen and we used to tie an instrument called radiosonde to it and then release the balloon. It would give the temperature, dew point temperature, wind speed and direction, and relative humidity at various levels in the atmosphere. We used to get data up to 16 – 17 km from the mean sea level which was very useful to study the entire atmospheric profile. The findings from all over the country would then be plotted on a weather map for analysis,” he said.
In the present day, the balloon method has been replaced by numeric weather prediction models which are mostly automated. But the synoptic and climatic knowledge of the scientists and the topography of a place is important in analysing the data that is derived from the model, the scientist noted.
Doppler Weather Radar shortly expected
Every weather enthusiast in Bengaluru has long been asking when the Doppler Weather Radar, which helps in very accurate prediction of weather data, will be installed in the city. Mr. Prasad said that if everything goes well, then 2024 might be the year when the radar would be installed.
“We are looking at sites now. A land parcel was purchased near Hessarghatta earlier for this purpose, but it was not convenient because of the technicalities. The first criterion for a radar is that it should be on an elevated place where there are no obstructions, but in Bengaluru, there are skyscrapers everywhere. We have shortlisted some locations which cannot be disclosed. We are hopeful that the installation will happen in 2024,” he said.
Apart from the radar, the State will also get new weather tech such as lightning sensors and wind profilers to study upper atmosphere winds.
IMD Bengaluru network
The IMD Bengaluru currently has three full-time observatories — Bengaluru City, Kempegowda International Airport, and HAL Airport — and 25 to 30 rain gauges. Across the State, there are also full-time observatories in Chitradurga, Gadag, Belagavi, Kalaburagi, and Karwar where eight readings are taken in a day. In Mysuru, Honnavar, and Dharwad there are part-time observatories which take three readings in a day. There are also over 400 rainfall stations across the State where only rainfall data is recorded.
Not just regular weather updates, but IMD Bengaluru also provides agricultural forecasts, aviation current updates, and route forecasts which help people plan their transportation among other things.
