It’s a shot in the arm for scientists at the Indian Institute of Tropical Meteorology (IITM) working on its earth system model (ESM). The long-term climate model has been authenticated by the American Meteorological Society and accepted it in bulletins and IITM experts are looking forward to the next Intergovernmental Panel on Climate Change to present simulations based on the ESM model, which would be a first from India at IPCC.
“For the next IPCC, we should be able to participate and are working towards it. It will be the first time India will be putting up a model,” said acting IITM director Dr R Krishnan.
This will be a change from seasonal prediction to a long-term climate model covering all parameters — the model assesses data of nearly 100 years. The thrust being on Indian monsoon, the focus of building the ESM is mainly detection, attribution and projection of changes in the South Asian monsoon.
“It will be state-of-the-art seasonal prediction model, the Climate Forecast System version 2 adapted to a climate model suitable for extended climate simulations at IITM,” Krishnan explained. Former IITM director B N Goswami, part of the team, said CFS 2 has been successful in predicting Indian monsoon on seasonal time scales. This time it will be a century long simulation which will focus on the ocean model.
“Testing is on as it is a long-term project,” said Goswami.
CFS 2, though used for prediction of monsoon on seasonal time scales, a century long simulation shows biases in ocean mixed layer, resulting in a 1.5 degree Celsius variation in global mean surface air temperature, a cold bias in sea surface temperature and a cooler than observed troposphere which limits utility of the model to study climate change issues, he added.
To address these issues and develop Indian ESM, the ocean component was replaced with an improved version, he said.
It is the result of Indo-US collaboration and will contribute to IPCC simulations, a first from India. “This work documents newly-developed IITM climate model simulations, and demonstrates suitability to address climate variability and changes relevant to South Asian monsoon,” added the scientists.