Premium
Zonal intermediate currents in the equatorial Atlantic Ocean
Author(s) -
Ollitrault Michel,
Lankhorst Matthias,
Fratantoni David,
Richardson Philip,
Zenk Walter
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl025368
Subject(s) - geology , antarctic intermediate water , equator , oceanography , zonal and meridional , climatology , atmospheric sciences , geodesy , deep water , north atlantic deep water , latitude
Acoustic float data collected near 800 m depth, are used to map zonal mean currents within the Antarctic Intermediate Water (AAIW) tongue in the equatorial Atlantic. Alternating zonal jets of 2° latitudinal width are revealed between 6°S and 6°N. Displacements from profiling floats drifting near 1000 m depth, also reveal similar zonal jets at the base of the AAIW layer. The strongest jets (15 cm s −1 peak) are found at 4°S, 2°S, 0°, 2°N and 4°N. They are coherent longitudinally over order of 3000 km and, poleward of 1°S and 1°N, generally coherent vertically between 800 m and 1000 m. Large seasonal fluctuations exist at both levels: within 1° of equator, AAIW at 800 m flows westward (8 cm s −1 mean) in boreal summer and fall but eastward (3 cm s −1 mean) in winter, whereas the flow at 1000 m is eastward in late fall and winter.