The scope of the book is outlined with specific examples of phenomenology that are outlined and explained in subsequent chapters. The necessity of bridging electrostatic and topological correlations to understand the behavior of charged macromolecules is addressed.

An overview of optical scattering in the atmosphere includes the sizes and concentration of scatterers, the mathematical formalism of scattering, and definitions of the lidar scattering and extinction coefficients. The Rayleigh, Mie, and geometric scattering regimes are defined by the scattering parameter, and implications of Rayleigh scattering on lidar measurements are elucidated for both signals and background. Molecules store energy in translational, rotational, and vibrational motions, and atoms store energy in electronic excitations. These energy storage mechanisms cause the lidar observables of Doppler shifts, molecular and Raman spectra, and atomic spectra, which, along with Rayleigh scattering, enable lidar measurements of temperatures and winds; water vapor and trace gas concentrations; and aerosol extinction coefficients at altitudes from the surface up to the mesosphere and lower thermosphere. The lidar techniques that exploit all these phenomena operate over a range of wavelengths from the long wave infrared to the ultraviolet and the reasons for the differing wavelengths of the various techniques are explained with a graphic that summarizes the chapter.

This chapter introduces important concepts such as Gouy-Chapman length, double-layer, Manning condensation, and regularization of the charge of a geometrical object in electrolyte solutions. A clear description of counterion distribution around charged objects is presented.

Master the principles of structural dynamics with this comprehensive and self-contained textbook, with key theoretical concepts explained through real-world engineering applications.

• The theory of natural modes of vibration, the finite element method, and the dynamic response of structures is balanced with practical applications to give students a thorough contextual understanding of the subject.

• Enhanced coverage of damping, rotating systems, and parametric excitation provides students with superior understanding of these essential topics.

• Examples and homework problems, closely linked to real-world applications, enrich and deepen student understanding.

• Curated mathematical appendices equip students with all the tools necessary to excel, without disrupting coverage of core topics.

• Containing all the material needed for a one- or two-semester course, and accompanied online by MATLAB/Python code, this authoritative textbook is the ideal introduction for graduate students in aerospace, mechanical, and civil engineering.

Given the easy embodiment of water vapor in air and its short residence times, the lower atmosphere is one of the critical pathways in the global hydrologic cycle; it transports water and energy around the globe without regard to continental boundaries and thus links the continents, the upper atmosphere, and the oceans. The transport and distribution of water vapor in the lower atmosphere, where it is most abundantly present, are among the main factors controlling precipitation and evaporation from the surface; these processes, in turn, determine soil and groundwater storage, and the different runoff phenomena. For purposes of practical analysis, the lower atmosphere can be treated as a turbulent boundary layer, allowing the application of similarity techniques to describe transport not only of water vapor, but also of momentum and sensible heat. The magnitudes of these transport phenomena and their interactions in the lower atmosphere are constrained by the surface energy budget as a critical boundary condition.

This brief epilogue emphasizes that this book is a gateway to new avenues in addressing living matter and new water-based materials.

Early prehistoric accounts of water cycling in nature refer only to, or hint at, the atmospheric phase of the water cycle. Wherever evaporation is alluded to, it is mostly assumed to take place from rivers and the sea. Speculations on the origin of these streams or on whether or how their water returns to where the streams originated, came later in Greek antiquity. This era produced essentially four competing theories on this, namely the seawater filtration theory, the underground condensation theory, the concept of pre-existing underground primal water, likely based on mythology and less accepted by the philosophers, and the rainfall percolation theory. Although the latter contains the essence of our present understanding, it took nearly another 23 centuries before it became the only remaining one to be fully accepted. In recorded history it can be followed as a thread running through the works of the pre-Socratics, the post-Aristotelian Peripatetics, Vitruvius in ancient Rome, Buridan and other medieval Schoolmen, Bartas, Palissy, and Gassendi in the Renaissance, Mariotte, Ray, and Van Musschenbroek at the dawn of modern science, and finally Dalton in the early nineteenth century.

For some purposes, the physical processes relating current runoff to precipitation can best be assumed to take place at the scale of the catchment, without consideration of the detailed subscale processes or for the intricate flow paths inside the watershed. The most common implementation of this idea has been the unit hydrograph (UH), which is based on the assumptions of linearity and stationarity. A UH is characterized by the duration of its precipitation input; this allows the definition of the instantaneous UH, that is the response of a catchment to a delta function precipitation input, or its Green’s function. The UH of a catchment can be identified from available data using the method of least squares. To facilitate the concise parameterization of UH functions for identification and prediction purposes, various conceptualizations have been proposed consisting of different combinations of linear translation elements and linear storage elements. Attempts have been made to extend the UH concept by allowing for nonstationarity and nonlinearities in the response. Long-term streamflow response to mean annual precipitation has also been the subject of many studies.

Master the principles of structural dynamics with this comprehensive and self-contained textbook, with key theoretical concepts explained through real-world engineering applications.

• The theory of natural modes of vibration, the finite element method, and the dynamic response of structures is balanced with practical applications to give students a thorough contextual understanding of the subject.

• Enhanced coverage of damping, rotating systems, and parametric excitation provides students with superior understanding of these essential topics.

• Examples and homework problems, closely linked to real-world applications, enrich and deepen student understanding.

• Curated mathematical appendices equip students with all the tools necessary to excel, without disrupting coverage of core topics.

• Containing all the material needed for a one- or two-semester course, and accompanied online by MATLAB/Python code, this authoritative textbook is the ideal introduction for graduate students in aerospace, mechanical, and civil engineering.

A brief overview and description of the atmospheric lidar measurement technique is followed by the structure of the atmosphere in terms of the troposphere, stratosphere, and mesosphere, as it is usually presented in atmospheric science and meteorology. The atmosphere is then described in terms of lidar observables at all altitudes, including water vapor; trace gases; clouds; several other kinds of particulate matter; and metal atoms, as well as density, temperature, and winds. Examples of lidar measurements include tropospheric and stratospheric ozone, greenhouse gases, other pollutants, tropospheric and stratospheric aerosols, polar stratospheric clouds, and atoms of sodium, potassium, calcium, and iron in the mesosphere. Finally, the structure and contents of the book are described, and suggestions for further reading are given.

This chapter begins with a brief review of electronic circuitry and terminology because optical detection and signal processing are in the realm of electrical engineering. A detailed discussion of analog detection follows, with circuitry including transimpedance amplifiers and equivalent circuits for analyzing noise and bandwidth. Two electronic noise sources are introduced, Johnson noise and amplifier noise, and their effects on SNR are modeled. Photon counting is then discussed in terms of its instrumentation, advantages, and limitations. The basic principles of coherent detection are elucidated through a mathematical derivation, and the advantages of coherent detection are shown: high SNR, optical background discrimination, and the measurement of Doppler shifts to sense winds. The main types of detectors used in lidar systems are then discussed, including intrinsic and PIN photodiodes, photomultipliers, avalanche photodiodes, and single-photon avalanche diodes. The advantages of internal detector gain for optimizing SNR are quantified.