Motion Of Long Waves Research Articles

Prognosis of 500-mb surface by divergent barotropic model

Forecasts of 500 mb surface by simple barotropic model which excludes divergence and ground contour effects, have been found to suffer from retrograde motion of ultra long waves. In this paper the effects of divergence term on the forecasts have been studied. 'It is shown that inclusion of the divergence term leads to an improvement in the 24-hr barotropic forecast for 500.mb level. It also produces a vastly improved 48 hours prognosis. Effects of the ground contour term are also discussed.

Roles of surface tension and Reynolds stresses on the finite amplitude stability of a parallel flow with a free surface

Subcritically stable motion of long gravity waves of finite amplitude in a liquid layer flowing down an inclined plane is shown to be impossible. However, super-critically stable wave régimes for such flows are found and curves of constant wave amplitude in such régimes are obtained. The mechanism of non-linear stability is investigated by considering the energy transfer between the mean flow and the disturbances. The results obtained show that the mechanism of stability in a parallel flow with a free surface is quite different from that in a parallel flow without a free surface.

A STUDY OF VARIATIONS OF THE GENERAL CIRCULATION

Changes of the general circulation, especially the strength of the upper westerlies, over 28 months are investigated quantitatively.The role of the high troposphere, represented by the 300-mb level, is stressed and it is sought to determine whether the tropics have any measurable influence on middle-latitude weather. Computations cover the latitude belt 10°N to 70°N, at least for part of the periods studied. To bring out the fluctuations clearly, they are expressed in terms of deviations from seasonal and mean latitudinal gradients. These deviations amount to over 20 per cent of the mean circulation, even in the belt of strongest westerlies. The concern is not with very small values whose accuracy would be questionable. When the latitudinal distribution of deviations, especially those of momentum of the westerlies, is plotted against time, definite long-term trends appear. Bands of high and low westerly momentum gradually traverse the latitude circles, sometimes from north to south, but usually from south to north. Momentum maxima and minima hardly ever form in middle latitudes. They approach the jet-stream region from equator or pole and pass across it, continuing on their poleward or equatorward course. A synoptic example shows the effect of a traveling momentum maximum on the northern hemisphere during several stages of its motion. Coincident weather developments, such as typhoon formations and long-wave motion, are noted.

XXXIV. The general motion of long waves, with an examination of the direct reflexion of the solitary wave

(1900). XXXIV. The general motion of long waves, with an examination of the direct reflexion of the solitary wave. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 50, No. 304, pp. 349-352.