Chapter 9
Inertial Currents in Western Continental Black
Sea Shelf
Maria-Emanuela Mihailov
Abstract The western Black Sea shelf has the largest width of the continental
platform of entire Black Sea basin, except for the north-western corner. The Black
Sea dynamics is driven by two synergic mechanisms: the considerable river input in
the north-western corner, deflected southward by the Coriolis force and the surface
wind stress that has an average anticlockwise curl. Their combined action controls
the global mass transport in the upper (active) layer. In this paper, in-situ measurements of the currents data and diagnostic calculations for the inertial currents are
analysed and discussed. The purpose of the present work is to furnish relevant
arguments using the Progressive Vector Diagram as well as the Discrete Fourier
Transform on the sea currents data and to report the results on inertial motion in the
western Black Sea shelf. The selected time series were recorded in the middle of the
Romanian shelf, at 44
10
0 N, 29
22
0 E (52 m of water depth), with the one or two
instruments suspended from a ship anchored for several days, only one series at the
southern end of the Mamaia bight at 44
12
0 N–28
20
0 E (12 m water depth). The
depth-averaged current amplitudes varied by time from 7.6 to 21.3 cm/s. Calculated
inertial currents periods in the north-western Black Sea range between 16.5 and
17.5 h.
Keywords Black Sea • Inertial currents • Sea currents • Progressive Vector
Diagram • Discrete Fourier Transform
9.1 Introduction
Inertial flow is the type of movement that is supposed to be accelerated only by the
Coriolis force per mass unit, without being affected by the frictional force. The
inertial motion, as shown by K. Rossby in1930s, is manifested in fluids by the
balance of gravitational force and the Coriolis force. Upon termination of the
M.-E. Mihailov (*)
National Institute for Marine Research and Development “Grigore Antipa”
Constanta – Romania, Mamaia Blvd. No. 300, RO-900591 Constanta, Romania
e-mail: emihailov@alpha.rmri.ro; http://www.rmri.ro
© Springer International Publishing AG 2018
C.W. Finkl, C. Makowski (eds.), Diversity in Coastal Marine Sciences, Coastal
Research Library 23, DOI 10.1007/978-3-319-57577-3_9
143
Inertial Currents in Western Continental Black
Sea Shelf
Maria-Emanuela Mihailov
Abstract The western Black Sea shelf has the largest width of the continental
platform of entire Black Sea basin, except for the north-western corner. The Black
Sea dynamics is driven by two synergic mechanisms: the considerable river input in
the north-western corner, deflected southward by the Coriolis force and the surface
wind stress that has an average anticlockwise curl. Their combined action controls
the global mass transport in the upper (active) layer. In this paper, in-situ measurements of the currents data and diagnostic calculations for the inertial currents are
analysed and discussed. The purpose of the present work is to furnish relevant
arguments using the Progressive Vector Diagram as well as the Discrete Fourier
Transform on the sea currents data and to report the results on inertial motion in the
western Black Sea shelf. The selected time series were recorded in the middle of the
Romanian shelf, at 44
10
0 N, 29
22
0 E (52 m of water depth), with the one or two
instruments suspended from a ship anchored for several days, only one series at the
southern end of the Mamaia bight at 44
12
0 N–28
20
0 E (12 m water depth). The
depth-averaged current amplitudes varied by time from 7.6 to 21.3 cm/s. Calculated
inertial currents periods in the north-western Black Sea range between 16.5 and
17.5 h.
Keywords Black Sea • Inertial currents • Sea currents • Progressive Vector
Diagram • Discrete Fourier Transform
9.1 Introduction
Inertial flow is the type of movement that is supposed to be accelerated only by the
Coriolis force per mass unit, without being affected by the frictional force. The
inertial motion, as shown by K. Rossby in1930s, is manifested in fluids by the
balance of gravitational force and the Coriolis force. Upon termination of the
M.-E. Mihailov (*)
National Institute for Marine Research and Development “Grigore Antipa”
Constanta – Romania, Mamaia Blvd. No. 300, RO-900591 Constanta, Romania
e-mail: emihailov@alpha.rmri.ro; http://www.rmri.ro
© Springer International Publishing AG 2018
C.W. Finkl, C. Makowski (eds.), Diversity in Coastal Marine Sciences, Coastal
Research Library 23, DOI 10.1007/978-3-319-57577-3_9
143