A new study from the University of Hyderabad (UoH) in collaboration with the University of Exeter (UK) claims to have found out decadal prediction skills for the Indian Ocean Dipole (IOD) to enable monsoon forecast for the next 5-10 years in advance.
Scientists analysed retrospective decadal forecasts, with initial conditions from 1960 to 2011 from existing four models and found that two models — MIROC5 from Japan, and CanCM4 from Canada — show significant prediction skills for up to 10 years, with strongest leads up to two years.
Interestingly, the predictability of IOD comes from the subsurface ocean signals in the Southern Ocean. The El Nino-Southern Oscillation events, which occur in the tropical pacific, are also well known as a major climate driver. IOD affects the global climate with a positive phase characterised by above normal sea surface temperature in the equatorial eastern Indian Ocean, and below normal temperatures in the western equatorial Indian Ocean.
Strong positive IOD events in 2019, 2007, 1997,1994, 1967 1963, 1961, etc. are associated with strong rains along the Indian monsoon trough region. Conversely, it also causes below normal rainfall in Indonesia and Australia, heat waves in Japan and Europe, and East Africa, and fires in Australia and Indonesia.
The latest extreme positive IOD occurred in 2019 summer, contributing to the unprecedented wildfire season in Australia, floods in East Africa and above normal rainfall and floods in India. The impact can be seen all the way till Europe and Americas as well. Negative IOD affects the Indian monsoon trough. In fact, this was prominent till August and is a likely factor for the below normal rainfall in north India.
While predicting IOD well in advance would be beneficial for the society, the lead prediction skills are limited to a few months with just 1-2 models showing the skills to predict the eastern Indian Ocean temperatures at the lead of a few seasons to one year.
Scientists say better decadal prediction skills are possible given the improved models and larger number of observations assimilated.
The research was carried out by professor K. Ashok, research student Feba Francis, and Satish Shetye, a former chair professor of Centre for Earth, Ocean and Atmospheric Sciences, UoH, in collaboration with Mat Collins of University of Exeter, said an official release. It was featured in ‘Frontiers in Climate’ journal.
Meanwhile, Advanced Centre of Research in High Energy Materials, a DRDO’s centre of excellence at UoH, has recently been granted a patent for their invention ‘Green Method for the Synthesis of Bis(Fluoroalkyl)Carbonate’. Project scientist Balaka Barkakaty and her two assistants Saheli Dey and Nitesh Singh are the inventors of this patent. This patented invention outlines an ‘easy, green, no-solvent and cost-effective method’ for producing various types of bis(fluoroalkyl)carbonates in high purity and high yields.