Mpanza, M. A. ThaboTandon, Neil F.2022-06-282022-06-28202210.1007/s00382-022-06268-3http://hdl.handle.net/10315/39498enThis version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use (https://www.springernature.com/gp/open-research/policies/accepted-manuscript-terms), but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00382-022-06268-3Earth sciences::Atmosphere and hydrosphere sciencesPreprint