The Atlantic Circulation and Climate Experiment (ACCE) is directed at increasing our understanding of the interaction between the Atlantic Ocean and global climate. As a contribution to ACCE, NOAA joins several other NSF-funded investigators in deploying a North Atlantic wide PALACE float array to study the processes important in establishing sea-surface temperature (SST) variability. NOAA's area of interest is the tropical Atlantic and PALACE floats were deployed along 6°S and the equator to provide current vectors at the sea surface and 1000m and temperature profiles every 10 days. These data not only will provide a regional perspective to address ACCE objectives, but when combined with other floats and observations and models, a basinwide perspective will be available.
The cruise SJ9703, conducted during the summer of 1997 aboard the R/V Seward Johnson, represents one of NOAA's contributions to ACCE. During this cruise, 19 PALACE floats were deployed along 6°N and 6°S. In addition to deploying the PALACE floats, two basinwide transects were occupied at the same latitudes, and a partial transect along the equator. CTD and XBT data were collected along the sections to study upper water column processes and the water mass transformations that occur between 6°S and 6°N (e.g., the effects of equatorial upwelling on upper layer water masses). Comparing direct current observations that include non-geostrophic components of flow with geostrophic estimates of current will provide a measure of the accuracy of Ekman transport estimates close to the equator.
The cruise 2000-01 took place in January 2000 aboard the R/V Seward Johnson. 12 PALACE were deployed along 25.5°W and 23°W. Additionally three CTD/LADCP sections were occupied. XBT data were collected between the stations. 8 drifters were launched to supplement the GOOS network. The obtained data will be used to study the variability of the temperatures and the circulation in the tropical Atlantic.