Mississippi River water in the Florida Straits and in the Gulf.pdfVIP

GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L14606, doi:10.1029/2005GL022942, 2005 Mississippi River water in the Florida Straits and in the Gulf Stream off Georgia in summer 2004 Chuanmin Hu,1 James R. Nelson,2 Elizabeth Johns,3 Zhiqiang Chen,1 Robert H. Weisberg,1 and Frank E. Mu¨ller-Karger1 Received 17 March 2005; revised 13 June 2005; accepted 15 June 2005; published 19 July 2005. [1] A coherent plume from the Mississippi River was speculated that a low salinity water patch observed in the detected in MODIS imagery in July–October 2004 Gulf Stream (GS) off Georgia was of MR origin, but they extending from the eastern Gulf of Mexico into the had no observations to establish the connection to the Florida Straits (FS), and reaching the Gulf Stream (GS) GOM. Following a period of very high discharge (the off Georgia. The plume was sampled from ships in the 1993 MR flood), surface drifter, satellite infrared imagery FS and the GS. In early August, the plume was about and ship sampling data also suggested entrainment of a 10–20 km wide in the western FS and about 50 km wide plume of MR water into the Florida Current and GS [Ortner off Georgia. The FS ship survey (16–26 August) et al., 1995]. Numerical circulation models show that there documented a 50 km, 10–20 m deep band with are three possible routes by which the MR plume can get to anomalies in surface salinity ( 0.8), temperature the Florida Keys [ Weisberg et al., 2005, and references (0.5C), and surface chlorophyll concentration (2 ) therein]. However, direct observations of connectivity relative to FS waters outside the plume. Nutrient betwee