ISSN:0309-1929    

DOI:10.1080/03091927908243777

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

We carry out a linear stability analysis of fluid layers under uniform rotation which possess both vertical and horizontal temperature gradients. In order to represent vnrious latitudes with these plane parallel layers we use a rotation vector which is generally oblique to gravity. We consider ideal fiuids without diffusion within a Boussinesq approximation. This simplified configuration is used to assess the preferred convective modes as a function of latitude on a planet like Jupiter. The tilted rotation vector introduces a preference for roll-like disturbanas. with north-south orientations, while the horizontal temperature gradient produces a thermal wind shear which favors convective rolls oriented parallel to the flow in an east-west direction. With both these effects present we find that the horizontal ternperature gradient needed to produce a preference for the axisymmetric or east-west rolls increases with increasing rotation rate and decreasing latitude. The results also indicate that shells with warm-equators have a much stronger preference for east-west rolls than do shells with cold equators. In addition we find that the tilted rotation vector serves to make the symmetric modes unstable even for stable vertical stratifications with Richardson numbers greater than one.

ISSN:0309-1929    

DOI:10.1080/03091927908243778

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The time-dependent problem of inviscid stratified flow over finite obstacles in fluid of infinite depth is considered in the limit of vanishing stratification (Nu/U→0), as a perturbation about the state of potential flow. The object of this study is to shed light on the “upstream influence” question, namely, under what circumstances does the motion of the obstacle generate steady motions which will eventually be felt at an arbitrarily large distance upstream? In the present study the flow develops on both short and long length and time scales, and a matched asymptotic expansion procedure is required. The results from this expansion are consistent with those from the corresponding “classical” expansion in small obstacle height [McIntyre (1972)). In particular, no permanent effects far upstream are obtained by this procedure, and this implies that “Long's model” is applicable for the case of infinite depth ifNh/Uis sufficiently small.

ISSN:0309-1929    

DOI:10.1080/03091927908243779

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In an ocean with a horizontal bottom where no wind is blowing it is shown that the spin (angular momentum) of the ocean is conserved. Thus, when energy is dissipated, at least one of three things will happen: i) Wave spectra may move towards lower frequencies. ii) The directional distribution may be changed towards long-crested waves. iii) Shear currents may be generated. By neglecting ii) and iii), the frequency shift of a spectrum is calculated due to molecular dissipation. When all energy transforming phenomena as e.g. wave breaking and turbulence generation are taken into account, the conservation of spin seems to be able to explain the frequency shift of wave spectra. In shallow water it is shown that there is energy transfer from the waves to shear currents.

ISSN:0309-1929    

DOI:10.1080/03091927908243780

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Daily pressuresP(t) measured in Modena, Italy, from 1869 to 1976 have been studied statistically. As a function of time,t, the pressure can be expressed in an additive way, more precisely asP(t)=EP(t)+ RP(t), whereEP(t) is a deterministic function having a fundamental period of one year, andRP(t) is a stochastic function.

ISSN:0309-1929    

DOI:10.1080/03091927908243781

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0309-1929    

DOI:10.1080/03091927908243782

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0309-1929    

DOI:10.1080/03091927908243783

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor