The 8.2 kyr BP event simulated by a global atmosphere-sea-ice-ocean model

Seven freshwater perturbation experiments were performed with a global atmo sphere-sea-ice-ocean model to study the mechanism behind the 8.2 kyr BP Hol ocene cooling event. These experiments differed in initial state and durati on of the applied freshwater pulse, while the amount of freshwater was kept constant (4.67x10(14) m(3)). One of the scenarios, with freshwater added t o the Labrador Sea at a rate of 0.75 Sv during 20 years, resulted in weaken ing of the North Atlantic thermohaline circulation during 320 years and sur face cooling varying from 1 to 5 degreesC over adjacent continents. This re sult is consistent with proxy data, suggesting that a meltwater-induced wea kening of the thermohaline circulation caused the event. Moreover, our resu lts indicate that the time-scale of the meltwater release and the initial s tate are important, as both have a strong effect on the magnitude and durat ion of the produced model response.