>Figure 1 is an ocean current map of the Western North Atlantic that illustrates the location of the Gulf Stream. The image was cropped from the Ocean Currents map available from Wikimedia Commons:
The grid areas used for this post are shown in Figure 2. They cover the Gulf Stream from Florida to the waters South of Nova Scotia. The original NOAA Hurricane Tracking map is available here:
North and East of the last area highlighted, the Gulf Stream becomes the North Atlantic Drift. The transition point varies from map to map, so the area shown in brown is as far as I elected to follow the current.
Figure 3 is a spaghetti graph showing the SST anomalies of all of the areas. The SST anomalies for the majority of the Gulf Stream datasets peaked in the 1940s to 1950s. And for most, the present SST anomalies are well below those peak levels.
For the Gulf Stream waters off the east coast of Florida and the coast of Georgia, the SST anomalies, Figure 4, peaked in the late-1930s. SST anomalies then decreased until the 1990s, and have been rising to present.
The SST anomalies of the dataset covering the Gulf Stream from Georgia to Long Island, Figure 5, show a period of elevated SST anomalies that lasted from the late-1930s to approximately 1950. The SST anomalies decreased sharply until the mid-1960s and have been fluctuating significantly since that time without any apparent regularity.
The two datasets covering the areas of the Gulf Stream from North Carolina to Nova Scotia are illustrated in Figure 6. The SST anomalies of both datasets rose from approximately 1900 and peaked in 1949. They then dropped sharply until the mid-to-late 1960s and have also been fluctuating significantly without an apparent regularity. The sharp rises in 1998, though, appear to be a response to the 1997/98 El Nino.
The dataset for the waters South of Nova Scotia, Figure 7, is the first to show SST anomalies that are lower in the 1930s through 1950s than they are at present.
However, refer again to Figure 3. It shows that the present SST anomalies for the “Nova Scotia” (brown) dataset are still well within the range of variability for all of the Gulf Stream SST anomalies datasets.
The SST anomaly data are ERSST.v2, available through the KNMI Climate Explorer website:http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere