Climate bifurcations in a Schwarzschild equation model of the Arctic atmosphere

Abstract. A column model of the Arctic atmosphere is developed including nonlinear positive feedback responses surface albedo and water vapour to temperature. The treated as a grey gas flux longwave radiation governed by two-stream Schwarzschild equations. Water concentration determined Clausius–Clapeyron equation. Representative pathways (RCPs) are used carbon dioxide concentrations into future. resulting 9D two-point boundary value problem solved under various RCPs solutions analysed. predicts that highest pathway, climate will undergo an irreversible bifurcation warm steady state, which would correspond annually ice-free conditions. Under lowest corresponding very aggressive emission reductions, exhibits only mild increase in temperatures. two intermediate pathways, temperatures more substantially, system enters region bistability where external perturbations could possibly cause switch warm, state.