Tareev Equatorial Undercurrent
in the Indian Ocean
Albert K. Ambrosimov, Dmitry I. Frey and Sergey M. Shapovalov
Introduction
In February 2017, in cruise 42 of the R/V “Akademik Boris Petrov”, measurements
of the currents at two meridional sections in the equatorial zone of the Indian Ocean
were performed using a lowered ADCP instrument. The aim of the work was to
study the distribution of velocities in the upper 700-m layer of the ocean, including
the subsurface Tareev undercurrent, named after the Soviet oceanographer Boris
Tareev [1]. For the first time this current was discovered in 1960 during the First
International Indian Ocean Expedition during cruise 31 of the R/V “Vityaz”. Here
we cannot agree with Schott and McCreary [7], who noted that this undercurrent
was first documented by Taft [9]. We would like to send the mentioned authors to
the publication of Ovchinnikov [4], which describes the discovery of this equatorial
undercurrent.
Subsequently, the study of the Tareev current in the system of the equatorial
currents of the Indian Ocean was carried out in numerous expeditions. A rather
complete summary of the results collected during 30 years is presented in the
monograph by Neiman et al. [3]. We also note two later reviews [7, 8].
The previous studies show that one of the determining factors in the formation of
the circulation in the upper layer in the equatorial zone of the Indian Ocean is the
periodic change in the monsoon winds that affect the currents of this region. Relatively stable southeastern trade winds are observed south of 10° S; north of this
latitude there is a strong variability of winds associated with the monsoon periodicity. As distinguished from the tropical parts of the Atlantic and Pacific Oceans,
there is a deficiency of stable eastern winds along the equator during the year.
Equatorial winds have an eastern component only at the end of winter/early spring.
A. K. Ambrosimov ( ✉ ) ⋅ D. I. Frey ⋅ S. M. Shapovalov
Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
e-mail: ambrosimov@ocean.ru
© Springer International Publishing AG, part of Springer Nature 2018
M. G. Velarde et al. (eds.), The Ocean in Motion, Springer Oceanography,
https://doi.org/10.1007/978-3-319-71934-4_31
495
in the Indian Ocean
Albert K. Ambrosimov, Dmitry I. Frey and Sergey M. Shapovalov
Introduction
In February 2017, in cruise 42 of the R/V “Akademik Boris Petrov”, measurements
of the currents at two meridional sections in the equatorial zone of the Indian Ocean
were performed using a lowered ADCP instrument. The aim of the work was to
study the distribution of velocities in the upper 700-m layer of the ocean, including
the subsurface Tareev undercurrent, named after the Soviet oceanographer Boris
Tareev [1]. For the first time this current was discovered in 1960 during the First
International Indian Ocean Expedition during cruise 31 of the R/V “Vityaz”. Here
we cannot agree with Schott and McCreary [7], who noted that this undercurrent
was first documented by Taft [9]. We would like to send the mentioned authors to
the publication of Ovchinnikov [4], which describes the discovery of this equatorial
undercurrent.
Subsequently, the study of the Tareev current in the system of the equatorial
currents of the Indian Ocean was carried out in numerous expeditions. A rather
complete summary of the results collected during 30 years is presented in the
monograph by Neiman et al. [3]. We also note two later reviews [7, 8].
The previous studies show that one of the determining factors in the formation of
the circulation in the upper layer in the equatorial zone of the Indian Ocean is the
periodic change in the monsoon winds that affect the currents of this region. Relatively stable southeastern trade winds are observed south of 10° S; north of this
latitude there is a strong variability of winds associated with the monsoon periodicity. As distinguished from the tropical parts of the Atlantic and Pacific Oceans,
there is a deficiency of stable eastern winds along the equator during the year.
Equatorial winds have an eastern component only at the end of winter/early spring.
A. K. Ambrosimov ( ✉ ) ⋅ D. I. Frey ⋅ S. M. Shapovalov
Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
e-mail: ambrosimov@ocean.ru
© Springer International Publishing AG, part of Springer Nature 2018
M. G. Velarde et al. (eds.), The Ocean in Motion, Springer Oceanography,
https://doi.org/10.1007/978-3-319-71934-4_31
495