CHAOTIC MOTION PRODUCED IN FREE CONVECTIVE AND INERTIAL MOTION OF ATMOSPHERE

In this paper a nonlinear model of convective and inertial motion of atmosphere with damping is studied with Melnikov's function method. The results show that in the atmospheric motion under periodic forcing chaos can occur independently whether the atmospheric motion is stable or not; and it is the key to produce chaos that the distribution of relevant physical quantity is nonlinear and periodically drives exists. The formulae calculating the parameter ranger in which chaos occur are given as well.

Efficient turbulent compressible convection in the deep stellar atmosphere

We report on an application of gas-kinetic BGK scheme to the computation of turbulent compressible convection in the stellar interior. After incorporating the Sub-grid Scale （SGS） turbulence model into the BGK scheme, we tested the effects of numerical parameters on the quantitative relationships among the thermodynamic variables, their fluctuations and correlations in a very deep, initially gravity-stratified stellar atmosphere. Comparison indicates that the thermal properties and dynamic properties are dominated by different aspects of numerical models separately. An adjustable Deardorff constant in the SGS model cu, = 0.25 and an amplitude of artificial viscosity in the gas-kinetic BGK scheme C2 = 0 are appropriate for the current study. We also calculated the densityweighted auto- and cross-correlation functions in Xiong＇s turbulent stellar convection theory based on which the gradient type of models of the non-local transport and the anisotropy of the turbulence were preliminarily studied. No universal relations or constant parameters were found for these models.

Atmospheric Convection Model Based Digital Confidentiality Scheme

Nonlinear dynamics is a fascinating area that is intensely affecting a wide range of different disciplines of science and technology globally.The combination of different innovative topics of information security and high-speed computing has added new visions into the behavior of complex nonlinear dynamical systems which uncovered amazing results even in the least difficult nonlinearmodels.The generation of complex actions froma very simple dynamical method has a strong relation with information security.The protection of digital content is one of the inescapable concerns of the digitally advanced world.Today,information plays an important role in everyday life and affects the surroundings rapidly.These digital contents consist of text,images,audio,and videos,respectively.Due to the vast usage of digital images in the number of social and web applications,its security is one of the biggest issues.In this work,we have offered an innovative image encryption technique based on present criteria of confusion and diffusion.The designed scheme comprises two major nonlinear dynamical systems.We have employed discrete fractional chaotic iterative maps to add confusion capability in our suggested algorithm and continuous chaotic Lorenz system.We have verified our offered scheme by using statistical analysis.The investigations under the statistical tests suggested that our proposed technique is quite reasonable for the security of digital data.

Role of mesoscale eddies on atmospheric convection during summer monsoon season over the Bay of Bengal: A case study

Our study aims to understand the variability of oceanic mesoscale eddies during contrasting(2009 and 2013)monsoon seasons and the role of such eddies on atmospheric deep convection over the Bay of Bengal(BoB).Oceanic eddies are detected and tracked using sea surface height anomalies(SSHA),by employing the Okubo-Weiss parameter eddy detection method.Significant differences in the SSHA and eddy activity are evident during the contrasting monsoon years.During the year 2013(2009),anticyclonic eddies are predominant(absent)in the eastern BoB and longer(shorter)lifespans of cyclonic eddies are observed in the northern and western BoB.Analysis of time-longitude SSHA and zonal wind stress reveals the presence of strong(weak)equatorial downwelling Kelvin waves,coastal Kelvin waves and Rossby waves in the BoB during 2013(2009)Indian summer monsoon(ISM).The variability of eddies in the BoB during contrasting monsoons is attributed by the remote forcing effect of planetary scale waves.Our study is extended to investigate the associated atmospheric deep convection over the regions of cyclonic and anticyclonic eddies.Lag-correlations demonstrates that SSHA leads the outgoing longwave radiation by four days over anticyclonic eddy regions.Findings from the present study provide new insight into the internal dynamics of the ocean.