RED TIDE 2000 CAN WE PREDICT RED TIDES IN THE WESTERN GULF OF MEXICO ? Dr. Sonia C. Gallegos Dr. Melba M. Crawford Dr. Xiaogang Chen Naval Research Lab University of Texas at Austin Sverdrup Technology Inc. Stennis Space Center Center for Space Research Advanced System Group Mississippi 39529 Austin, Texas 78712 Mississippi 39529

Initiation site of red tide 2000 as observed by SeaWIFS on 17 Aug 2000

Red Tide 2000 as observed by SeaWiFS on 18 September 2000

RED TIDE 2000 Loop Current 1997

SEA SURFACE HEIGHT FROM ERS-2

RED TIDE 2000 Monthly probability of Loop Current position, 1998

RED TIDE 2000 Monthly probability of Loop Current position, 2000

RED TIDE 2000 Loop Current occurrences in NW GOM Grid distribution

RED TIDE 2000 Sea Surface High

RED TIDE 2000 Area of 0-isopleth intrusion over SW Texas continental shelf Grid distribution

RED TIDE 2000 Monthly probability of Loop Current position, 1996

RED TIDE 2000 Monthly probability of Loop Current position, 1993

RED TIDE 2000 Loop Current occurrences in NE GOM Grid distribution

RED TIDE 2000 Monthly probability of Loop Current position, 1994

RED TIDE 2000 SUMMARY The displacements of the Loop current appear to play a role in all the red tide occurrences in the West, East and North Gulf of Mexico. Red tides appear occur when the LC or the fringes of an associated eddy displace over the continental shelf during the Summer months. 3. Red tides occur in the Western Gulf when the Western boundary of the LC crosses 87o W 4. The year-2000-red tide started at a site where the effluent of the Sabine River met the “0-5” isopleths in ERS-2 data during the first 15 days of July 2000. 5. Red tide occurrences in other years appear to occur at sites where ”0-5” isopleths met river outflows over the continental shelf during the Summer months. 6. A statistical automated forecasting system can be developed utilizing the data and findings from this work for use by the TPWD.