How scientists used tech meant to monitor nuclear explosions to predict monsoon

CHENNAI: International scientists are now using data from monitors meant to detect nuclear explosions to decode the ‘complex’ Indian monsoon, which is increasingly becoming erratic.

In this novel method, a scientist based in Belgium is using data from the Comprehensive Test Ban Treaty Organisation (CTBTO) monitors in Dubna area of Russia and Melbourne in Australia to predict the monsoon in Kerala.

What’s interesting is that this system can predict the onset, intensity, and withdrawal of monsoon with unprecedented accuracy — about two months in advance with an error margin of about three days, compared to the Indian Meteorological Department’s warning time of 1-3 weeks.

Lucrezia Terzi, who works with the Belgian Nuclear Research Centre, is leading a group of scientists researching on the subject.

She says that using the concentration levels of Beryllium-7 in the atmosphere, scientists can perfect the prediction of monsoon. Beryllium-7 is a natural radionuclide, which originates high in the atmosphere.

It is formed out of the interaction between cosmic radiation and air molecules and moves to the earth’s surface with the global atmospheric circulation.

“It has long been known that the concentration of Beryllium-7 fluctuates constantly in the atmosphere. Now we can also link the values we measure at different locations to monsoon rains,” Lucrezia told Express.

“We collected IMS data of the two stations measured between 2003 and 2018 and compared our forecast model with the IMD monsoon onset dates for corresponding years and found a link.”

“The average concentrations of Beryllium-7 fluctuate. If the concentrations in Australia were low, we found high concentrations in Russia, and vice-versa. The point at which the data of both countries intersect is called Hadley-Ferrel Convergence Zone (HFCZ), which can be linked to the monsoon rains,” explains Lucrezia.

These radioactive isotopes are regularly detected by the radionuclide monitoring network of the International Monitoring System (IMS) commanded by the CTBTO.

Lucrezia’s work is peer-reviewed and published in ‘Nature’ (scientific journal) and she has made a detailed presentation during the recently concluded CTBT Science and Technology Conference-2019 in Vienna, Austria, which was attended by this correspondent on the invitation of the CTBTO.

“It has long been known that the concentration of Beryllium-7 fluctuates constantly in the atmosphere. Now we can also link the values we measure at different locations to monsoon rains,” Lucrezia told Express.

“We collected IMS data of the two stations measured between 2003 and 2018 and compared our forecast model with the IMD monsoon onset dates for corresponding years and found a link.”The scientists have shared the data with the Australian Ambassador in India for the benefit of Indian authorities.

Traditionally, meteorologists follow Intertropical Convergence Zone (ITCZ), which is associated with periods of frequent and intense precipitation, typically lasting for a few months.

However, this new forecast model based on Beryllium-7 would indicate the date of monsoon onset even before the conditions turn favourable, said Martin B Kalinowski, chief, Capacity Building and Training Section in the International Data Centre (IDC), CTBTO and co-contributor to the research.

However, he said this forecast model can be further fine-tuned by the Indian scientists for better results, which could benefit farmers.