Timing and structure of Mega-SACZ events during Heinrich Stadial 1 - Stríkis, Nicolás Misailidis; Chiessi, Cristiano Mazur; Cruz, Francisco W; Vuille, Mathias; Cheng, Hai; Barreto, Eline Alves de Souza; Mollenhauer, Gesine; Kasten, Sabine; Karmann, Ivo; Edwards, R. Lawrence; Bernal, Juan Pablo; Sales, Hamilton dos Reis (Geophysical Research Letters, 2015)