FORCING OF GULF STREAM POSITION AND STRENGTH BY WIND AND OCEAN CIRCULATION

The Gulf Stream (GS) is the western boundary current of the North Atlantic Subtropical Gyre, which in turn is part of the Atlantic Meridional Overturning Circulation (AMOC). As a wind driven gyre, the Gulf Stream is sensitive to changes in the dominant wind patterns represented by the North Atlantic Oscillation (NAO). Under the current global climate changes, the NAO and AMOC could experience changes, which would then force the Gulf Stream to change, either by strengthening (weakening) or shifting its position to the north (south). In this paper, we analyse observational data for the NAO index and the AMOC (provided by the RAPID array and statistical reconstruction) and correlate them to the observed changes in the Gulf Stream over the past 23 years, obtained from satellite altimetry. The Gulf Stream has been divided into three sections to account for any permanent fixtures affecting its downstream behaviour. We have found that there are strong correlations between the NAO/ AMOC and the position of the Gulf Stream, but not many correlations that significantly explain the weakening of the Gulf Stream. The eastern part of the Gulf Stream has been identified as a possible indicator for the overall Gulf Stream behaviour, as it shows the same trends as the GS over the past 23 years, as well as robust correlations to NAO and AMOC