COMPLEX GROWTH RATE EVOLUTION IN A LATITUDINALLY WIDESPREAD SPECIES

Evolution ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 862 ◽  
Author(s):  
M. Julian Caley ◽  
Lin Schwarzkopf
Keyword(s):  
Growth Rate ◽  
Widespread Species ◽  
Complex Growth Rate

scholarly journals COMPLEX GROWTH RATE EVOLUTION IN A LATITUDINALLY WIDESPREAD SPECIES

Evolution ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 862-869 ◽  
Author(s):  
M. Julian Caley ◽  
Lin Schwarzkopf
Keyword(s):  
Growth Rate ◽  
Widespread Species ◽  
Complex Growth Rate

Bounds for growth rate of a perturbation in thermohaline convection

1981 ◽  
Vol 378 (1773) ◽  
pp. 301-304 ◽  
Keyword(s):  
Growth Rate ◽  
Prandtl Number ◽  
Taylor Number ◽  
Governing Equations ◽  
Thermohaline Convection ◽  
Rayleigh Numbers ◽  
Complex Growth Rate

A new scheme of combining the governing equations of thermohaline convection is shown to lead to the following bounds for the complex growth rate p of an arbitrary oscillatory perturbation: | p | 2 < R s σ (Veronis thermohaline configuration), | p | 2 < – R σ (Stern thermohaline configuration), where R and R s are the thermal and the concentration Rayleigh numbers, and σ is the Prandtl number. The analysis is applicable to rotatory thermal and rotatory thermohaline convections for which the corresponding bounds are | p | 2 < T σ 2 (rotatory simple Bénard configuration), | p | 2 < max ( T σ 2 , R s σ) (rotatory Vernois thermohaline configuration), | p | 2 < max ( T σ 2 , – R σ) (rotatory Stern thermohaline configuration), where T is the Taylor number. The above results are valid for all combination of dynamically free and rigid boundaries.

scholarly journals Bounds for the growth of a perturbation in some double-diffusive convection problems

1983 ◽  
Vol 25 (2) ◽  
pp. 276-285 ◽  
Author(s):  
J. R. Gupta ◽  
S. K. Sood ◽  
R. G. Shandil ◽  
M. B. Banerjee ◽  
K. Banerjee
Keyword(s):  
Growth Rate ◽  
Fluid Mechanics ◽  
Newtonian Fluid ◽  
Double Diffusive Convection ◽  
Diffusive Convection ◽  
Complex Growth Rate ◽  
Double Diffusive

AbstractBounds are presented for the modulus of the complex growth rate p of an arbitrary oscillatory perturbation, neutral or unstable, in some double-diffusive problems of relevance in oceanography, astrophysics and non-Newtonian fluid mechanics.

Transverse instabilities of deep-water solitary waves

2006 ◽  
Vol 462 (2071) ◽  
pp. 2039-2061 ◽  
Author(s):  
Bernard Deconinck ◽  
Dmitry E Pelinovsky ◽  
John D Carter
Keyword(s):  
Growth Rate ◽  
Deep Water ◽  
Wave Train ◽  
Two Dimensional ◽  
Nls Equation ◽  
One Dimensional ◽  
Hill’S Method ◽  
Real Growth ◽  
Dimensional Soliton ◽  
Complex Growth Rate

The dynamics of a one-dimensional slowly modulated, nearly monochromatic localized wave train in deep water is described by a one-dimensional soliton solution of a two-dimensional nonlinear Schrödinger (NLS) equation. In this paper, the instability of such a wave train with respect to transverse perturbations is examined numerically in the context of the NLS equation, using Hill's method. A variety of instabilities are obtained and discussed. Among these, we show that the solitary wave is susceptible to an oscillatory instability (complex growth rate) due to perturbations with arbitrarily short wavelength. Further, there is a cut-off on the instability with real growth rates. We show analytically that the nature of this cut-off is different from what is claimed in previous works.

scholarly journals On triply diffusive convection in completely confined fluids

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2579-2585
Author(s):  
Jyoti Prakash ◽  
Shweta Manan ◽  
Virender Singh
Keyword(s):  
Growth Rate ◽  
Coupled System ◽  
Upper Bounds ◽  
Governing Equations ◽  
Confined Fluids ◽  
Diffusive Convection ◽  
Convection Problem ◽  
Triply Diffusive Convection ◽  
Complex Growth Rate

The present paper carries forward Prakash et al. [21] analysis for triple diffusive convection problem in completely confined fluids and derives upper bounds for the complex growth rate of an arbitrary oscillatory disturbance which may be neutral or unstable through the use of some non-trivial integral estimates obtained from the coupled system of governing equations of the problem.

Drought Tolerance and Avoidance in the Localised and Endemic Leptospermum grandiflorum and Co-occurring Species

1993 ◽  
Vol 6 (6) ◽  
pp. 559 ◽  
Author(s):  
J Blake ◽  
GJ Jordan
Keyword(s):  
Growth Rate ◽  
Drought Tolerance ◽  
Water Relations ◽  
East Coast ◽  
Widespread Species ◽  
Apparent Lack ◽  
Small Areas ◽  
Restricted Distribution ◽  
Historical Factors

A physiological case study of the genus Leptospermum is used to highlight the importance of the historical effects of the dry Last Glacial (30 000–15 000 BP) on current plant distributions in Tasmania. The water relations of the endemic L. grandiforum Lodd., which has a restricted distribution, is contrasted with three widespread taxa of this genus. The results suggest that L. grandiflorum is better suited for survival in dry areas, to which its distribution is restricted, than the more widespread species. Leptospermum grandiflorum is also shown to have a slower growth rate under moist conditions than the widespread taxa, which perhaps explains its apparent lack of dispersal during the moister interglacial. Thus, historical factors are likely to be the cause of the restricted distribution of this localised endemic to small areas of the east coast of Tasmania.

scholarly journals Linear stability analysis for monami in a submerged seagrass bed

2015 ◽  
Vol 786 ◽  
Author(s):  
Ravi Singh ◽  
M. M. Bandi ◽  
Amala Mahadevan ◽  
Shreyas Mandre
Keyword(s):  
Growth Rate ◽  
Steady Flow ◽  
Linear Instability ◽  
Flow Profile ◽  
Seagrass Beds ◽  
Seagrass Bed ◽  
Helmholtz Instability ◽  
Model Predictions ◽  
Mode 2 ◽  
Complex Growth Rate

The onset of monami – the synchronous waving of seagrass beds driven by a steady flow – is modelled as a linear instability of the flow. Unlike previous works, our model considers the drag exerted by the grass in establishing the steady flow profile, and in damping out perturbations to it. We find two distinct modes of instability, which we label modes 1 and 2. Mode 1 is closely related to Kelvin–Helmholtz instability modified by vegetation drag, whereas mode 2 is unrelated to Kelvin–Helmholtz instability and arises from an interaction between the flow in the vegetated and unvegetated layers. The vegetation damping, according to our model, leads to a finite threshold flow for both of these modes. Experimental observations for the onset and frequency of waving compare well with model predictions for the instability onset criteria and the imaginary part of the complex growth rate respectively, but experiments lie in a parameter regime where the two modes can not be distinguished.

scholarly journals On the Modulation of Oscillation in Thermohaline Convection Problems Using Temperature Dependent Viscosity

2015 ◽  
Vol 45 (1) ◽  
pp. 39-52
Author(s):  
Joginder Singh Dhiman ◽  
Vijay Kumar
Keyword(s):  
Growth Rate ◽  
Linear Stability Theory ◽  
Effect Of Temperature ◽  
Sufficient Condition ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Thermohaline Convection ◽  
The Stability ◽  
Dependent Viscosity ◽  
Complex Growth Rate

Abstract The present paper mathematically investigates the effect of temperature dependent viscosity on the onset of instability in thermohaline convection problems of Veronis and Stern type configurations, using linear stability theory. A sufficient condition for the stability of oscillatory modes for thermohaline configuration is derived. When the compliment of this sufficient condition is true, the oscillatory motions of neutral or growing amplitude may exist, and hence the bounds for the complex growth rate of these neutral or unstable modes are derived, when viscosity of the fluid is an arbitrary function of temperature. Some general conclusions for the cases of linear and exponential variations of viscosity are worked out. The present analysis thus shows that the oscillations in thermohaline convection problems can be modulated or arrested by considering the temperature dependent viscosity of the fluid.

Sign in / Sign up

Export Citation Format

Share Document