LONG-PERIOD CHANGES IN THE BOTTOM WATER FLOWING THROUGH VEMA CHANNEL

Further details of the ''warming'' of bottom water flowing through the Vema Channel, first reported by Zenk and Hogg [1996], are given. Beca use cross-channel gradients of temperature are large and the channel i s narrow, careful analysis is required to determine whether or not the bottom water temperature minimum was adequately sampled by a particul ar station or cruise. During a period from 1972 to 1996, at least 14 v isits with quality hydrographic measurements have been made to the reg ion. Of these, 11 were judged successful, and their data indicate an a brupt rise in potential temperature by 0.03 degrees C front -0.18 degr ees C to -0.15 degrees C in the early 1990s that has remained until th e latest observation in the spring of 1996. Although this observation is consistent with the report of warming of Antarctic Bottom Water in the Argentine Basin by Coles et al. [1996], their associated conclusio n that this water mass has also freshened by 0.008 psu (on potential d ensity surfaces) is in contradiction with our finding of no measurable change.