Extreme climate after massive eruption of Alaska’s Okmok volcano in 43 BCE and its effects on the late Roman Republic and Ptolemaic Kingdom by McConnell, JR, Sigl, M, Plunkett, G, Burke, A, Kim, WM, Raible, C, Wilson, AI, Manning, JG, Ludlow, FM, Chellman, NJ, Innes, HM, Yang, Z, Larsen, JF, Schaefer, JR, Kipfstuhl, S, Mojtabavi, S, Wilhelms, F, Opel, T, Meyer, H, Steffensen, JP