Usually you can easily download sea ice concentration gridded products from NSIDC website: https://nsidc.org/data/search#keywords=sea+ice

There are a number of sources fo sea ice concentration data. I will try to list some of the popular ones here.

1. https://nsidc.org/data/soac/sea-ice-concentration (This is a good starting point to explore about SIC)

2. https://seaice.uni-bremen.de/sea-ice-concentration/amsre-amsr2/

3. https://osi-saf.eumetsat.int/products/sea-ice-products

And about the seasons, you can follow this website: https://www.antarcticglaciers.org/antarctica-2/introductory-antarctic-resources/seasons-of-antarctica/

A good approach to sea ice concentration is also given here with the austral seasons mentioned explicitly.

https://journals.ametsoc.org/view/journals/clim/30/6/jcli-d-16-0408.1.xml

There was a paper by Dr Joseph Comiso that mentioned the months of the seasons. I am not able to find that at the moment.

Cheers!

Kamaljit