Author: Joanna K. Barstow Publisher: ISBN: Category : Languages : en Pages :
Book Description
Global Cloud Properties on Venus from Orbital Infrared Spectroscopy This thesis describes the derivation of Venusian global cloud properties from in- frared remote sensing data obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the European Space Agency Venus Express satellite. A computationally-efficient retrieval method is designed to exploit the dataset, which provides coverage of the entire nightside southern hemisphere of Venus. Spatially- resolved near-infrared spectra have been used to derive improved models of the vertical structure and global distribution of cloud properties in the southern hemi- sphere. Wavelengths within transparency windows in the 1.0-2.6 J.Lm range covered by VIRTIS are sensitive on the nightside to absorption by the lower and middle sul- phuric acid cloud layers, which are back-lit by thermally-emitted radiation from the hot lower atmosphere (Taylor et al. 1997). The cloud model used to interpret the spectra builds on work by Crisp (1986), Pollack et al. (1993) and Grinspoon et al. (1993). Retrieved parameters are the acid concentration in the cloud droplets, the average size of the particles in the lower cloud and the altitude of the cloud base in the model. Values are estimated initially using wavelength pairs selected for their unique sensitivity to each parameter, and then validated using model spectra generated using the NEMESIS radiative transfer and retrieval code (Irwin et al. 2008) as developed for Venus (Tsang et al. 2008a). The spatial variation of sulphuric acid concentration in the cloud particles is esti- mated; the concentration is found to be higher in regions of optically thick cloud. The retrieved cloud base altitude varies with latitude, reaching a maximum height near -500 before falling by several km towards the pole. An increase in average particle size near the pole (Wilson et al. 2008) and latitudinally-variable CO abun- dance at 35-40 km altitude (Tsang et al. 2008) are both confirmed. A decrease in tropospheric H20 abundance at high latitudes is observed, and provides evidence for strong downwelling between ±60 and ±75° latitude, which marks the poleward extent of the Hadley cell circulation. Long-term secular change is also observed over a period of two Earth years. The measurements presented here provide a reference dataset for microphysical and dynamical modelling of the cloud deck, and the role of the cloud as a dynamical and chemical tracer means that such observations aid understanding of the Venusian atmosphere.
Author: Larry W. Esposito Publisher: John Wiley & Sons ISBN: 0875904416 Category : Science Languages : en Pages : 243
Book Description
Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 176. With the search for extra-solar planets in full gear, it has become essential to gain a more detailed understanding of the evolution of the other earth-like planets in our own solar system. Space missions to Venus, including the Soviet Veneras, Pioneer Venus, and Magellan, provided a wealth of information about this planet' enigmatic surface and atmosphere, but left many fundamental questions about its origin and evolution unanswered. This book discusses how the study of Venus will aid our understanding of terrestrial and extra-solar planet evolution, with particular reference to surface and interior processes, atmospheric circulation, chemistry, and aeronomy. Incorporating results from the recent European Venus Express mission, Exploring Venus as a Terrestrial Planet examines the open questions and relates them to Earth and other terrestrial planets. The goal is to stimulate thinking about those broader issues as the new Venus data arrive.
Author: Lennart Bengtsson Publisher: Springer Science & Business Media ISBN: 1461450640 Category : Science Languages : en Pages : 188
Book Description
ESA’s Venus Express Mission has monitored Venus since April 2006, and scientists worldwide have used mathematical models to investigate its atmosphere and model its circulation. This book summarizes recent work to explore and understand the climate of the planet through a research program under the auspices of the International Space Science Institute (ISSI) in Bern, Switzerland. Some of the unique elements that are discussed are the anomalies with Venus’ surface temperature (the huge greenhouse effect causes the surface to rise to 460°C, without which would plummet as low as -40°C), its unusual lack of solar radiation (despite being closer to the Sun, Venus receives less solar radiation than Earth due to its dense cloud cover reflecting 76% back) and the juxtaposition of its atmosphere and planetary rotation (wind speeds can climb up to 200 m/s, much faster than Venus’ sidereal day of 243 Earth-days).
Author: Stephen Wesley Bougher Publisher: University of Arizona Press ISBN: 9780816518302 Category : Science Languages : en Pages : 1384
Book Description
The final orbit of Venus by the Magellan spacecraft in October 1994 brought to a close an exciting period of Venus reconnaissance and exploration. The scientific studies resulting from data collected by the Magellan, Galileo, and Pioneer missions are unprecedented in their detail for any planet except Earth. Venus II re-evaluates initial assessments of Venus in light of these and other spacecraft missions and ground-based observations conducted over the past 30 years. More than a hundred contributors summarize our current knowledge of the planet, consider points of disagreement in interpretation, and identify priorities for future research. Topics addressed include geology, surface processes, volcanism, tectonism, impact cratering, geodynamics, upper and lower atmospheres, and solar wind environment. The diversity of the coverage reflects the interdisciplinary nature of Venus science and the breadth of knowledge that has contributed to it. A CD-ROM developed by the Jet Propulsion Laboratory accompanies the book and incorporates text, graphics, video, software, and various digital products from selected contributors to the text. A multimedia interface allows users to navigate the text and the extensive databases included on the disk. Venus II is the most authoritative single volume available on the second planet. Its contents will not only help shape the goals of future Venus missions but will also enhance our understanding of current Mars explorations.
Author: K. N. Liou Publisher: Elsevier ISBN: 0080491677 Category : Science Languages : en Pages : 598
Book Description
This Second Edition of An Introduction to Atmospheric Radiation has been extensively revised to address the fundamental study and quantitative measurement of the interactions of solar and terrestrial radiation with molecules, aerosols, and cloud particles in planetary atmospheres. It contains 70% new material, much of it stemming from the investigation of the atmospheric greenhouse effects of external radiative perturbations in climate systems, and the development of methodologies for inferring atmospheric and surface parameters by means of remote sensing. Liou's comprehensive treatment of the fundamentals of atmospheric radiation was developed for students, academics, and researchers in atmospheric sciences, remote sensing, and climate modeling. Balanced treatment of fundamentals and applications Includes over 170 illustrations to complement the concise description of each subject Numerous examples and hands-on exercises at the end of each chapter
Author: Muriel Gargaud Publisher: Springer Nature ISBN: 3662650932 Category : Science Languages : en Pages : 3376
Book Description
Now in its third edition the Encyclopedia of Astrobiology serves as the key to a common understanding in the extremely interdisciplinary community of astrobiologists. Each new or experienced researcher and graduate student in adjacent fields of astrobiology will appreciate this reference work in the quest to understand the big picture. The carefully selected group of active researchers contributing to this work are aiming to give a comprehensive international perspective on and to accelerate the interdisciplinary advance of astrobiology. The interdisciplinary field of astrobiology constitutes a joint arena where provocative discoveries are coalescing concerning, e.g. the prevalence of exoplanets, the diversity and hardiness of life, and its chances for emergence. Biologists, astrophysicists, (bio)-chemists, geoscientists and space scientists share this exciting mission of revealing the origin and commonality of life in the Universe. With its overview articles and its definitions the Encyclopedia of Astrobiology not only provides a common language and understanding for the members of the different disciplines but also serves for educating a new generation of young astrobiologists who are no longer separated by the jargon of individual scientific disciplines. This new edition offers ~170 new entries. More than half of the existing entries were updated, expanded or supplemented with figures supporting the understanding of the text. Especially in the fields of astrochemistry and terrestrial extremophiles but also in exoplanets and space sciences in general there is a huge body of new results that have been taken into account in this new edition. Because the entries in the Encyclopedia are in alphabetical order without regard for scientific field, this edition includes a section “Astrobiology by Discipline” which lists the entries by scientific field and subfield. This should be particularly helpful to those enquiring about astrobiology, as it illustrates the broad and detailed nature of the field.
Author: Joanna K. Barstow
Author: Larry W. Esposito
Author: Lennart Bengtsson
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Author: Stephen Wesley Bougher
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Author: Siegfried Böhme
Author: K. N. Liou
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Author: Muriel Gargaud