Changes in high latitude surface salinity have a strong effect on the North Atlantic Deep Water Formation (NADWF) which appears to be very important in driving the global thermohaline conveyor belt. Natural variations of sea surface salinity and sea ice have been observed in the North Atlantic, namely the Great Salt Anomaly (GSA) of the late sixties and seventies. When dealing with climate variability one must consider the sensitivity of the climate system to perturbations.In order to include the atmospheric heat transport mechanisms we coupled an atmosphere energy balance model with a 3-D ocean general circulation model which includes a thermodynamic sea ice model. We explore the feedback mechanisms in the ocean-atmosphere-sea ice system affecting the thermohaline circulation (THC) under perturbations in sea surface salinity at high latitudes.