L-mode to H-mode transition triggered by sawtooth-induced heat flux in EAST

•The causal link between the sawtooth-induced heat pulses at the plasma edge and a spontaneous L-H transition is proposed.•The edge turbulence level increases significantly when the sawtooth-induced heat pulse arriving at the plasma edge.•First time to see that the turbulent decorrelation rate increases significantly just before the L-H transition by experiment.•Both turbulent decorrelation rate and nonlinear energy transfer rate play key roles on the turbulence quench.