Coriolis circulation

Because at higher latitudes the coriolis force deflects wind to a greater extent than in the tropics, winds become much more zonal (flow parallel to lines of latitude). Also in contrast to the persistent circulation of the tropics, the mid-latitude circulations are quite transient. There are large temperature contrasts, and temperature may vary abruptly over relatively short distances (frontal zones). In these regions of large temperature contrast, potential energy is frequently released and converted into kinetic energy as wind. Near the surface there are many closed pressure sys-... 

As a result of these factors (wind, Ekman transport, Coriolis force) the surface ocean circulation in the mid-latitudes is characterized by clockwise gyres in the northern hemisphere and the counterclockwise gyres in the southern hemisphere. The main surface currents around these gyres for the world s oceans are shown in Fig. 10-6. The regions where Ekman transport tends to push water together are called convergences. Divergences result when surface waters are pushed apart. 

We have now to go one step further and to build stellar evolution models where the transport of angular momentum will be followed self-consistently under the action of meridional circulation, shear turbulence, and internal gravity waves. In this path some important aspects still need to be clarified Can we better describe the excitation mechanisms and evaluate in a more reliable way the quantitative properties of the wave spectra What is the direct contribution of 1GW to the transport of chemicals, especially in the dynamical shear layer produced just below the convective envelope by the wave-mean flow interaction What is the influence of the Coriolis force on IGW How do 1GW interact with a magnetic field Work is in progress in this direction. 

The distribution of chemical components within the ocean is determined by both transportation and transformation processes. A brief outline of oceanic circulation is necessary to ascertain the relative influences. Two main flow systems must be considered. Surface circulation is established by tides and the prevailing wind patterns and deep circulation is determined by gravitational forces. Both are modified by Coriolis force, the acceleration due to the earth s rotation. It acts to deflect moving fluids i.e., both air and water) to the right in the northern hemisphere and to the left in the southern hemisphere. The magnitude of the effect is a function of latitude, being nil at the equator and increasing poleward. 

The Coriolis force becomes particularly important when fluid motion occurs at large scales, as in vast lakes such as Lake Michigan (Fig. 2-6 b), or in atmospheric circulation (Fig. 4-12). Figure 4-12 explains the origin of the Coriolis force in terms of the radial and tangential components of the velocity of a fluid parcel in a rotating mass of fluid. 

The Coriolis force, in conjunction with solar heating, creates a more complex global circulation pattern than that shown in Fig. 4-11. Three major latitudinal bands of surface winds result from these combined forces. In the Northern Hemisphere, the trade winds lie between the equator and approximately 30° latitude and are generally from the northeast (Fig. 4-13). North of the trade wind latitudes, between approximately 30° and 60° latitude, pole-ward-moving surface winds are deflected to the right by the Coriolis force, giving rise to the westerlies. Finally, from approximately 60° poleward, a third global-scale convective flow moves southward near Earth s surface and returns... 

Fig. 3.3 (a) Generalized atmospheric pressure, wind and precipitation patterns on an ocean-covered Earth (n. b. sphere is elongated to aid clarity of wind patterns), (b) Idealized major oceanic surface current systems in the Pacific and Atlantic oceans. The Coriolis effect is responsible for disruption of the meridional circulation cells between 30 and 60° in (a). 

In the temperate regions, between 40° and 55° latitude, influences of both tropical and polar regions are felt. The major feature of the temperate regions is large-.scale weather systems, which results in the circulation shown in Figure 1.2. The surface winds in the Northern Hemisphere are westerlies because of the Coriolis force. 

The test rig includes a 22 m long loop of 1 inch diameter and a 90-liter tank used to store adequate amounts of liquid hydrocarbon, deionized water, and gas. The liquid phase is circulated through the loop by means of a Moineau pump. The loop is fiuther equipped with a sapphire window located at the inlet of the pipe, a Coriolis flowmeter and a thermostatic device to adjust the temperature of the loop. A... 

The analytical approach used in Section IV.A.2 is not applicable to the tropical circulations, even though these are low-frequency phenomena, with time scales comparable to or longer than that of the extratropical circulation. The weakness of the Coriolis force in the tropics tends to decouple the zonal and meridional wind fields, so even at very low frequencies the EP-flux divergence acts mainly... 

The period of the SAO, on the other hand, is regulated by the seasonal cycle because of one crucial difference between the QBO and the SAO The westward wind phase of the SAO in the stratosphere (see Fig. 11) is produced, not by wave forcing, but by the advection of westward zonal-mean momentum by the mean meridional circulation. In the tropics, the term v Uy in Eq. (8) cannot be neglected with respect to the Coriolis force, which vanishes at the equator. As shown in Fig. 13, the meridional velocity v is relatively large near the stratopause and its direction is such as to produce negative (westward) zonal-mean zonal winds. 

The characteristics of air circulation in a cyclone can be explained in terms of four forces air pressure gradient, the Coriolis force, friction. 

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