ABSTRACT
The performance of CMIP6 models in simulating the sea-ice concentration (SIC) of the southern Indian Ocean region around [10E–100E; 55S–75S] covering both Indian Antarctic Stations Maitri and Bharati is evaluated against the corresponding satellite observations. Out of a total of 33 CMIP6 models used for the analysis, 25 models are categorized as good models and 8 as poor models. A large inter-model spread is noticed in the seasonal variability of SIC of the region, but the multi-model mean matches very well with the observed satellite data. It is found that the multi-model mean SIC time series of historical data for the period 1900–2014 as well as high greenhouse gas (GHG) concentration future projection SSP5–8.5 data for the period 2015–2100 shows a decreasing trend. The SIC will decrease at an alarming rate of nearly 0.2% per year in the SSP5–8.5 scenario. The effect of climate change on the predictability of the southern Indian Ocean SIC is quantified in terms of generalized Hurst exponent and Predictability Index. It is shown that the SIC of the southern Indian Ocean is predictable. With the increase in the GHG concentration, the predictability of southern Indian Ocean SIC will decrease. The SIC of the Maitri region is more predictable compared to the Bharati region. The predictability of the SIC of the Maitri and Bharati regions shall decrease in the SSP5–8.5 projection scenario during the years 2015–2100.
