Physical Processes in Earth and Environmental Sciences Phần 9

Chương 6Các mô hình chính của dòng chảy dốc từ mặt biển tính năng động. Lưu ý sự kiểm soát của các vectơ hiện tại (cả độ lớn và hướng) bởi độ lớn của gradient không gian trong địa hình nước.
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Physical Processes in Earth and Environmental Sciences Phần 9LEED-Ch-06.qxd 11/28/05 10:25 Page 258 258 Chapter 6 LOW LOW 0 0 H HIGH HIGH 0 H H H 0 0 0 LOW LOW LOW +1.3 m –1.1 m 0 HIGH LOW Fig. 6.24 The remarkable satellite-measured topography of the mean sea surface (with wave and tidal wave effects subtracted). LOW GS KS HIGH HIGH HIGH HIGH HIGH HIGH AC AC LOW LOW LOW Fig. 6.25 The major pattern of gradient flow from the computed dynamic sea surface. Note the control of current vectors (both magnitude and direction) by the magnitude of the spatial gradients in water topography, that is, OBL flow is parallel to the gradient lines, with an inten- sity proportional to grayscale thickness. Note western intensification of Pacific Kuroshio (KS) and Atlantic Gulf Stream (GS) currents and the strong circumpolar Antarctic current (AC). though complex, meandering filament of warm Caribbean We have seen that all moving fluid masses possess water in transit to the shores of northwest Europe vorticity appropriate to the latitude in which they find (Figs 6.26 and 6.27). In the mid-twentieth century, themselves (Section 3.8) and that the total, or absolute, vor- Stommel explained these most striking features of the ticity (f ) must be conserved. Thus a northward-moving general oceanic circulation by a consideration of both mass of water, impelled by wind shear to spin clockwise, will lateral friction and conservation of angular momentum. gain planetary vorticity as it moves. In order to keepLEED-Ch-06.qxd 11/27/05 2:33 Page 259 Outer Earth processes and systems 259 GS meanders sl cool MAB Mid- sl Atlantic Bight sl water MAB ...