Atmospheric dynamics of tidally synchronized extrasolar planets

2008 ◽  
Vol 366 (1884) ◽  
pp. 4477-4488 ◽  
Author(s):  
James Y.-K Cho
Keyword(s):  
Temperature Distribution ◽  
Solar System ◽  
Flow Pattern ◽  
Extrasolar Planets ◽  
Atmospheric Dynamics ◽  
Reliable Interpretation ◽  
Near Future ◽  
Theoretical Issues

Tidally synchronized planets present a new opportunity for enriching our understanding of atmospheric dynamics on planets. Subject to an unusual forcing arrangement (steady irradiation on the same side of the planet throughout its orbit), the dynamics on these planets may be unlike that on any of the Solar System planets. Characterizing the flow pattern and temperature distribution on the extrasolar planets is necessary for reliable interpretation of data currently being collected, as well as for guiding future observations. In this paper, several fundamental concepts from atmospheric dynamics, likely to be central for characterization, are discussed. Theoretical issues that need to be addressed in the near future are also highlighted.

From Dust to Life

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Extrasolar Planets ◽  
Planetary Systems ◽  
History Of Astronomy ◽  
Human Origins ◽  
History Of ◽  
The Subject ◽  
Emergence Of Life

The birth and evolution of our solar system is a tantalizing mystery that may one day provide answers to the question of human origins. This book tells the remarkable story of how the celestial objects that make up the solar system arose from common beginnings billions of years ago, and how scientists and philosophers have sought to unravel this mystery down through the centuries, piecing together the clues that enabled them to deduce the solar system's layout, its age, and the most likely way it formed. Drawing on the history of astronomy and the latest findings in astrophysics and the planetary sciences, the book offers the most up-to-date and authoritative treatment of the subject available. It examines how the evolving universe set the stage for the appearance of our Sun, and how the nebulous cloud of gas and dust that accompanied the young Sun eventually became the planets, comets, moons, and asteroids that exist today. It explores how each of the planets acquired its unique characteristics, why some are rocky and others gaseous, and why one planet in particular—our Earth—provided an almost perfect haven for the emergence of life. The book takes readers to the very frontiers of modern research, engaging with the latest controversies and debates. It reveals how ongoing discoveries of far-distant extrasolar planets and planetary systems are transforming our understanding of our own solar system's astonishing history and its possible fate.

scholarly journals Visions of Human Futures in Space and SETI

2017 ◽  
Author(s):  
Jason T. Wright ◽  
Michael P. Oman-Reagan
Keyword(s):  
Solar System ◽  
Science Fiction ◽  
Dark Matter Particle ◽  
Short Term ◽  
National Science ◽  
The Galaxy ◽  
Near Future ◽  
Far Future ◽  
Made In

We discuss how visions for the futures of humanity in space and SETI are intertwined, and are shaped by prior work in the fields and by science fiction. This appears in the language used in the fields, and in the sometimes implicit assumptions made in discussions of them. We give examples from articulations of the so-called Fermi Paradox, discussions of the settlement of the Solar System (in the near future) and the Galaxy (in the far future), and METI. We argue that science fiction, especially the campy variety, is a significant contributor to the ‘giggle factor’ that hinders serious discussion and funding for SETI and Solar System settlement projects. We argue that humanity's long-term future in space will be shaped by our short-term visions for who goes there and how. Because of the way they entered the fields, we recommend avoiding the term ‘colony’ and its cognates when discussing the settlement of space, as well as other terms with similar pedigrees. We offer examples of science fiction and other writing that broaden and challenge our visions of human futures in space and SETI. In an appendix, we use an analogy with the well-funded and relatively uncontroversial searches for the dark matter particle to argue that SETI's lack of funding in the national science portfolio is primarily a problem of perception, not inherent merit.Also on arXiv: https://arxiv.org/abs/1708.05318Please cite this version:Wright, Jason T., and Michael P. Oman-Reagan. “Visions of Human Futures in Space and SETI.” International Journal of Astrobiology, 2017, 1–12. doi:10.1017/S1473550417000222.

scholarly journals The Potential for Archaeology Within and Beyond the Habitable Zones (HZ) of the Milky Way

2004 ◽  
Vol 213 ◽  
pp. 505-510
Author(s):  
John B. Campbell
Keyword(s):  
Remote Sensing ◽  
Solar System ◽  
Milky Way ◽  
Extrasolar Planets ◽  
Habitable Zone ◽  
The Moon ◽  
Habitable Zones ◽  
Remote Sensing Techniques ◽  
Main Region

As archaeology is established on Earth and we are actively exploring the Solar System and beyond, there is the potential to develop a number of forms of exo-archaeology. The archaeology of the things intelligent species do in theory could be practised anywhere, provided one can detect the evidence. Sites are being created by us elsewhere within our star's habitable zone (HZ), namely on the Moon and Mars, and at least molecular traces of human-created probes are being left beyond the HZ (Venus, Jupiter etc.). The successful detection of extrasolar planets and the possible identification of HZs round other stars raise the possibility for the development of extrasolar archaeology, at least initially by remote sensing techniques. Within the Milky Way the main region to investigate is the galactic habitable zone (GHZ), though there could be archaeological traces of technological behaviours beyond it.

scholarly journals PlanetCARMA: A New Framework for Studying the Microphysics of Planetary Atmospheres

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1064
Author(s):  
Erika Barth
Keyword(s):  
Solar System ◽  
Extrasolar Planets ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Planetary Body ◽  
Solar System Bodies ◽  
Fortran 90 ◽  
Primary Advantage ◽  
New Framework ◽  
Modular Format

The Community Aerosol and Radiation Model for Atmospheres (CARMA) has been updated to apply to atmospheres of the Solar System outside of Earth. CARMA, as its name suggests, is a coupled aerosol microphysics and radiative transfer model and includes the processes of nucleation, condensation, evaporation, coagulation, and vertical transport. Previous model versions have been applied separately to the atmospheres of Solar System bodies and extrasolar planets. The primary advantage to PlanetCARMA is that the core physics routines each reside in their own self-contained modules and can be turned on/off as desired while a separate planet module supplies all the necessary parameters to apply the model run to a particular planet (or planetary body). So a single codebase is used for all planetary studies. PlanetCARMA has also been updated to Fortran 90 modular format. Examples of outer solar system atmosphere applications are shown.

Multi-Cell Concept for Simulating Fires in Big Enclosures Using a Zone Model

1996 ◽  
Vol 14 (3) ◽  
pp. 186-198 ◽  
Author(s):  
W.K. Chow
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Physical Properties ◽  
Flow Pattern ◽  
Layer Thickness ◽  
Zone Model ◽  
Smoke Layer

The multi-cell concept is applied to simulate fire in a big com partment with the zone model CFAST. The predicted physical properties of the smoke layer are used to justify the results, including the smoke layer tempera ture, smoke layer thickness and flows between each cell. Microscopic pictures of the flow pattern and smoke temperature distribution similar to the results pre dicted by the Computational Fluid Dynamics technique can be obtained. This idea is recommended to study fires in big enclosures.

scholarly journals MEP and planetary climates: insights from a two-box climate model containing atmospheric dynamics

2010 ◽  
Vol 365 (1545) ◽  
pp. 1355-1365 ◽  
Author(s):  
Tim E. Jupp ◽  
Peter M. Cox
Keyword(s):  
Drag Coefficient ◽  
Entropy Production ◽  
Rotation Rate ◽  
Free Parameter ◽  
Extrasolar Planets ◽  
Climate Model ◽  
Analogous Result ◽  
Atmospheric Dynamics ◽  
Surface Drag ◽  
Box Models

A two-box model for equator-to-pole planetary heat transport is extended to include simple atmospheric dynamics. The surface drag coefficient C D is treated as a free parameter and solutions are calculated analytically in terms of the dimensionless planetary parameters η (atmospheric thickness), ω (rotation rate) and ξ (advective capability). Solutions corresponding to maximum entropy production (MEP) are compared with solutions previously obtained from dynamically unconstrained two-box models. As long as the advective capability ξ is sufficiently large, dynamically constrained MEP solutions are identical to dynamically unconstrained MEP solutions. Consequently, the addition of a dynamical constraint does not alter the previously obtained MEP results for Earth, Mars and Titan, and an analogous result is presented here for Venus. The rate of entropy production in an MEP state is shown to be independent of rotation rate if the advective capability ξ is sufficiently large (as for the four examples in the solar system), or if the rotation rate ω is sufficiently small. The model indicates, however, that the dynamical constraint does influence the MEP state when ξ is small, which might be the case for some extrasolar planets. Finally, results from the model developed here are compared with previous numerical simulations in which the effect of varying surface drag coefficient on entropy production was calculated.

scholarly journals On the Origins of Eccentric Close-in Planets

2008 ◽  
Vol 4 (S253) ◽  
pp. 189-195 ◽  
Author(s):  
Soko Matsumura ◽  
Genya Takeda ◽  
Fred A. Rasio
Keyword(s):  
Solar System ◽  
Quality Factor ◽  
Extrasolar Planets ◽  
External Perturbation ◽  
Central Star ◽  
Circular Orbits ◽  
Secular Perturbation ◽  
New Class ◽  
Stellar Ages ◽  
Host Stars

AbstractStrong tidal interaction with the central star can circularize the orbits of close-in planets. With the standard tidal quality factorQof our solar system, estimated circularization timescales for close-in extrasolar planets are typically shorter than the age of the host stars. While most extrasolar planets with orbital radiia≲ 0.1 AU indeed have circular orbits, some close-in planets with substantial orbital eccentricities have recently been discovered. This new class of eccentric close-in planets implies that either their tidalQfactor is considerably higher, or circularization is prevented by an external perturbation. Here we constrain the tidalQfactor for transiting extrasolar planets by comparing their circularization times with accurately determined stellar ages. Using estimated secular perturbation timescales, we also provide constraints on the properties of hypothetical second planets exterior to the known eccentric close-in planets.

Modeling on the Effect of Imbalance Burner Pressure and Mass Flow Rate in a Full-Scale Gas Fired Industrial Boiler

2003 ◽  
Author(s):  
Hasril Hasini ◽  
Mohd. Zamri Yusoff ◽  
Kamsani Abdul Majid ◽  
Mohd. Rizal Ramli ◽  
Hamdan Hassan ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Flow Pattern ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Combustion Process ◽  
General Purpose ◽  
Anticlockwise Direction ◽  
Industrial Boiler

CFD simulation of the combustion process in a 120MW gas fired industrial boiler has been performed, with focus on the flow pattern and temperature distribution at the reheater section in the furnace. The modeling was done using general-purpose CFD software, CFD-ACE+ developed by CFD Research Corporation. The effect of imbalance burner pressure is simulated by varying the mass flow rate of fuel (natural gas) injected at each burner. The simulation result shows good qualitative agreement with practical observation. The flow in the furnace is highly swirling with intense mixing and follows a helical pattern in an anticlockwise direction. Temperature distribution prior to entry to the reheater is significantly higher on the right side of the reheater. As a conclusion, the imbalance nozzles pressure creates uneven mass flow rate of air and fuel, which results in asymmetric flow pattern and temperature distribution at the reheater section.

scholarly journals Ensuring Civil and Political Rights in Vietnam Today - Some Theoretical, Legal, Practical Aspects

2019 ◽  
Vol 35 (4) ◽  
Author(s):  
Nguyen Thi Thanh Nga
Keyword(s):  
Political Rights ◽  
Civil And Political Rights ◽  
Near Future ◽  
Theoretical Issues

The article focuses on generalizing theoretical issues on civil and political rights, assurance of civil and political rights; ensuring civil and political rights in Vietnam through analyzing the provisions of the Constitution and laws and practices to ensure civil and political rights. On that basis, a solution is proposed to make a contribution to ensuring to make a contribution to ensuring civil and political rights in Vietnam in the near future.

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