Five years of Florida Current structure and transport from the Royal Caribbean Cruise Ship Explorer of the Seas

Using ship-of-opportunity platform Explorer of the Seas, five years of full-depth velocity data have been collected across the Florida Straits at 26 degrees N. Between May 2001 and May 2006 the mean transport of the Florida Current was 31.0 +/- 4.0 Sv. This compares to a mean transport of 32.4 +/- 3.2 Sv inferred from cable voltages at 27 degrees N over the same period, implying an average 1.4 Sv transport into the Straits through the Northwest Providence Channel. The climatological core of the Florida Current is 170 cms(-1) and is positioned at 79.8 degrees W, about 10 km east of the shelf break. The largest variability in velocity occurs over the shelf and shelf break and is likely related to shelf waves. A secondary maximum occurs across much of the Straits over the top 100 m of the water column and may be associated with wind events. The annual cycle of Florida Current transports has a range of 4.7 Sv, with a maximum in May-June-July and a minimum in January. The difference between the summer and winter current structure appears as a first baroclinic mode with zero crossing at 150 m. The maximum difference is about 15 cms(-1) at the surface and is centered just offshore of the mean current core. On interannual timescales, low-pass filtered Explorer and cable transports show similar downward trends between 2002 and 2005, but diverge over the last year or so of the record.