E-grāmata: Advances in Geophysics

Preface		ix
Shape and Microdynamics of Ice Particles and Their Effects in Cirrus Clouds		1	(302)
Pao K. Wang
Ice Particles in the Atmosphere		1	(6)
Ice Particles-A Personal Perspective		1	(2)
Some Historical Notes on the Knowledge of Ice Particles in Ancient China		3	(3)
A Brief Summary of the Following Sections		6	(1)
Mathematical Descriptions of Ice Particle Size and Shape		7	(36)
Size Distribution versus Size-Shape Distributions		7	(2)
Mathematical Expression Describing the Two-Dimensional Shapes of Hexagonal Ice Crystals		9	(2)
Approximating an Exact Hexagonal Plate		11	(2)
Two-Dimensional Characterization of an Ensemble of Planar Hexagonal Ice Crystals		13	(5)
Mathematical Expressions Describing the Three-Dimensional Shapes of Ice Crystals		18	(12)
Mathematical Expressions Describing Conical Hydrometeors		30	(13)
Hydrodynamics of Ice Particles		43	(66)
Fall Attitude of Ice Particles		43	(1)
Review of Previous Studies		44	(1)
The Physics and Mathematics of Unsteady Flow Fields around Nonspherical Ice Particles		45	(4)
The Numerical Scheme		49	(4)
Results and Discussion		53	(56)
Vapor Diffusion, Ventilation, and Collisional Efficiencies of Ice Crystals		109	(43)
Introduction		109	(1)
Vapor Diffusion Fields around a Stationary Columnar Ice Crystal		110	(14)
Ventilation Coefficients for Falling Ice Crystals		124	(13)
Collision Efficiencies of Ice Crystals Collecting Supercooled Droplets		137	(15)
Scavenging and Transportation of Aerosol Particles by Ice Crystals in Clouds		152	(45)
Importance of Aerosol Particles in the Atmosphere		152	(1)
Physical Mechanisms of Precipitation Scavenging		153	(2)
The Theoretical Problem of Ice Scavenging of Aerosol Particles		155	(1)
Physics and Mathematics of the Models		156	(8)
Efficiencies of Ice Plates Collecting Aerosol Particles		164	(8)
Efficiencies of Columnar Ice Crystals Collecting Aerosol Particles		172	(6)
Comparison of Collection Efficiency of Aerosol Particles by Individual Water Droplets, Ice Plates, and Ice Columns		178	(10)
Experimental Verification of Collection Efficiencies		188	(9)
Evolution of Ice Crystals in the Development of Cirrus Clouds		197	(62)
Cirrus Clouds, Radiation, and Climate		197	(2)
Physics of the Model		199	(12)
Design of the Present Simulation Study		211	(7)
Numerics of the Model		218	(1)
Results and Discussion		219	(27)
Appendix A. Area of an Axial Cross Section		246	(2)
Appendix B. Calculation of Volume		248	(1)
Appendix C. Closed-Form Expression of the Conical Volume		249	(3)
References		252	(7)
Mapping Spatial Variability of the Frequency-Magnitude Distribution of Earthquakes
Stefan Wiemer
Max Wyss
Introduction		259	(2)
Data Requirements		261	(8)
Estimating the Magnitude of Completeness		261	(3)
Tradeoff between Spatial Resolution and Significance		264	(1)
Maximizing the Number of Events		265	(1)
Mapping Minimum Magnitude of Completeness		265	(1)
Homogeneity of Reporting with Time		266	(1)
Contamination by Explosions		267	(1)
Magnitude Scales		267	(2)
Methods		269	(2)
Mapping the Seismicity		269	(1)
Computing the b-Value and Its Uncertainty		269	(2)
Case Studies of Mapping the b-Value in Various Tectonic Regimes		271	(13)
Volcanoes and Geothermal Fields		271	(2)
Mapping Asperities		273	(6)
Mapping Temporal Changes of Earthquake Probability		279	(1)
Changes of b with Depth in California		280	(1)
Mapping b in Subducting Slabs		281	(1)
Variations of b in Aftershock Sequences		281	(1)
Implications for Aftershock Hazard		282	(1)
Spatial Variations of b on Regional to Global Scales		283	(1)
Changes of b-Values as a Function of Time		284	(2)
Precursory Changes of b-Values before Main Shocks		285	(1)
Fractal Dimension and b-Value		286	(1)
The Physical Processes Perturbing b-Values		287	(1)
Common Problems and Complications		288	(3)
Catalog Heterogeneity as a Function of Time		288	(1)
The Lack of a Unique Physical Interpretation of Anomalies		288	(1)
Selective Hypocenter Location Errors as a Function of Magnitude		289	(1)
Magnitude Scales Can Differ		289	(1)
The Methods Can Only Be Applied to Seismically Active Volumes		289	(1)
Bimodel Distributions of Magnitudes		290	(1)
New Hypotheses and Preliminary Conclusions		291	(2)
Hypothesis I: Active Magma Chambers in Seismogenic Crust May Be Mapped by an Excess of Small Earthquakes, Which Can Be Measured by Anomalously Large b-Values		291	(1)
Hypothesis II: Asperities May Be Mapped by Maxima in Local Earthquake Probability (Minima in Local Recurrence Time)		291	(1)
Hypothesis III: The Permanent Changes in the Probability for Earthquakes Caused by Major and Large Shocks in Their Vicinity Can Be Estimated from the Changes in Local Recurrence Time, Calculated from Changes in a- and b-Values		292	(1)
Hypothesis IV: Phase Transitions, and Thus the Deep Source of Magma for Subduction Volcanism, May Be Mapped by Anomalously High b-Values		293	(1)
Hypothesis V: The b-Values in Aftershock Sequences Are Heterogeneous, Suggesting That the Probability of a Major Aftershock Varies in Space		293	(1)
Outlook and Future Work		293	(10)
Appendix A. Frequently Asked Questions		294	(1)
Should One Use Samples with Constant Numbers Rather Than with Constant Radius?		294	(1)
Why Do We Map b-Values and Not Mean Magnitude?		295	(1)
Should the Catalog Be Declustered?		295	(1)
What Is the Influence of Location Errors?		296	(1)
What Software Do You Use?		296	(1)
Acknowledgments		296	(1)
References		296	(7)
Index		303

Renata Dmowska works in the School of Engineering and Applied Sciences at Harvard University in Cambridge, MA, USA. Barry Saltzman, 1932-2001, was professor of geology and geophysics at Yale University and a pioneer in the theory of weather and climate, in which he made several profound and lasting contributions to knowledge of the atmosphere and climate. Saltzman developed a series of models and theories of how ice sheets, atmospheric winds, ocean currents, carbon dioxide concentration, and other factors work together, causing the climate to oscillate in a 100,000-year cycle. For this and other scientific contributions, he received the 1998 Carl Gustaf Rossby Research Medal, the highest award from the American Meteorological Society. Saltzman was a fellow of the American Meteorological Society and the American Association for the Advancement of Science and an honorary member of the Academy of Science of Lisbon. His work in 1962 on thermal convection led to the discovery of chaos theory and the famous "Saltzman-Lorenz attractor."