China 
Africa 
Explore chapters and articles related to this topic
Oceanographic Factors
Published in Ronald C. Chaney, Marine Geology and Geotechnology of the South China Sea and Taiwan Strait, 2020
Under ideal conditions, the Ekman spiral results in a net transport (Ekman transport) of wind-driven water in the affected water column (Ekman Layer), which is 90° to the right from the wind direction in the northern hemisphere and to the left in the southern hemisphere. In shallow water it will be somewhat less than 90° because of the restricting influence of the ocean bottom.
Spatio-temporal variations in upwelling indices in Arabian Sea coastal upwelling systems and associated biological productivity using remote sensing observations
Published in Journal of Operational Oceanography, 2023
Debojyoti Ganguly, K. Suryanarayana, Mini Raman
Both offshore Ekman transport and Ekman suction were found to be significant for the Yemen-Oman coastal regions while for the west coast of India, Ekman suction is very weak except at the southernmost part (8.5–9°N). The Yemen-Oman southwest monsoon upwelling is stronger than the south west coast of India upwelling, as evident from the wind-based upwelling indices and the LTG values. Prominent phytoplankton blooms were observed along Oman coast that extended offshore to the Central Arabian Sea. This is due to the combined effect of coastal upwelling due to Ekman transport and open ocean upwelling due to Ekman suction (Lee et al. 2000; Levy et al. 2007). Phytoplankton blooms near south west coast of India were less pronounced (Figure 11) due to low Ekman transport and low pumping. The southernmost part (8.5–9°N) of west coast of India, which had moderately high Ekman suction (1–2 m2/s) had more intense southwest monsoon blooms as compared to rest of the coastal region. Thus, differences in Ekman characteristics can help understand differences in upwelling-induced chlorophyll changes.
Frictional effects in wind-driven ocean currents
Published in Geophysical & Astrophysical Fluid Dynamics, 2021
Throughout the research literature various choices of depth-dependent eddy viscosities are investigated. The corresponding Ekman-type solutions all retain two of the fundamental properties of the classical, constant eddy-viscosity, Ekman flow: the depth-averaged mass flow (Ekman transport) is at right angles to the steady wind at the surface and the horizontal wind-induced current spirals to the right in the Northern Hemisphere, with a speed that decreases with increasing depth. On the other hand, the deflection angle of the surface current with respect to the direction of the steady wind presents significant deviations from the reference value of 45 of the classical Ekman flow. This issue is especially relevant for the climate, since the ocean stores most of the heat in its near-surface region. It is therefore of interest to investigate the frictional effects for a general depth-dependent eddy viscosity. While the direction of the Ekman transport can be established generally by means of a simple computation (see the first paragraph of section 3), the other aspects are more challenging.