NGRI sets up geothermal climate change observatory: Gives insight on temperatures 300 years ago

By Syed Akbar
Hyderabad, Aug 17: The city-based National Geophysical Research Institute has set up a geothermal climate change observatory at Choutuppal near here. The observatory is capable of recording and finding out warming or cooling of the earth in the last 300 years, besides giving data on the present scenario. It will also give clues on the meteorological conditions.

The observatory, which comprises an automatic weather station located next to a set of boreholes going down to 210 metres, will allow earth scientists to study how meteorologic variables affect ground temperature and eventually the deep rock temperature, according Dr VP Dimri, NGRI director.

"The datasets being acquired at the observatory will be invaluable for studies on global climate change and its signature in the solid Earth. This is the first geothermal climate change observatory of its kind in the low latitude belt (0-30 degrees N), and will allow comparisions with a similar observatory set up in Utah, USA in the higher lattitudes," he said.

The weather station samples the surface air temperature, humidity, precipitation, solar radiation, wind speed and direction at two second intervals and stores the information once every 15 minutes. The diurnal and annual variations of surface air temperature decay by about 50 cm and 15 mts of depth respectively.

The long term (10 to 100 years) changes insurface air temperature due to climate change diffuse down in the earth and perturb the natural temperature distribution up to depths of 100 to 200 metres. "By measuring the temperatures in a borehold today, scientists are able to infer both the magniturde and the onset time of warming (or cooling) that took place during the last 300 years, much before the start of the extensive meteorological records in India.