Terrestrial Hydrometeorology

Dr. Shuttleworth worked for 20 years at the UK’s Institute of Hydrology, ultimately as Head of the Hydrological Processes Division. In 1993 he joined the University of Arizona where he is Regents’ Professor in both the Department of Hydrology and Water Resources and the Atmospheric Sciences Department. He has served on numerous national and international scientific advisory committees, including the National Research Council, the International Council of Scientific Unions, the International Hydrology Programme, the International Geosphere-Biosphere Programme, and the World Climate Research Programme. In 2001 Dr. Shuttleworth was awarded the AGU Hydrology Prize for “outstanding contributions to the science of hydrology”, and in 2006 IAHS, UNESCO and WMO jointly awarded him the prestigious International Hydrology Prize.

• Foreword xviPreface xviiiAcknowledgements xix1 Terrestrial Hydrometeorology and the Global Water Cycle 1Introduction 1Water in the Earth system 2Components of the global hydroclimate system 4Atmosphere 5Hydrosphere 8Cryosphere 9Lithosphere 9Biosphere 10Anthroposphere 10Important points in this chapter 122 Water Vapor in the Atmosphere 14Introduction 14Latent heat 14Atmospheric water vapor content 15Ideal Gas Law 16Virtual temperature 17Saturated vapor pressure 18Measures of saturation 20Measuring the vapor pressure of air 21Important points in this chapter 233 Vertical Gradients in the Atmosphere 25Introduction 25Hydrostatic pressure law 26Adiabatic lapse rates 27Dry adiabatic lapse rate 27Moist adiabatic lapse rate 28Environmental lapse rate 28Vertical pressure and temperature gradients 29Potential temperature 30Virtual potential temperature 31Atmospheric stability 32Static stability parameter 32Important points in this chapter 344 Surface Energy Fluxes 36Introduction 36Latent and sensible heat fluxes 37Energy balance of an ideal surface 38Net radiation, Rn 38Latent heat flux, λE 39Sensible heat flux, H 39Soil heat flux, G 39Physical energy storage, St 40Biochemical energy storage, P 40Advected energy, Ad 41Flux sign convention 41Evaporative fraction and Bowen ratio 45Energy budget of open water 46Important points in this chapter 465 Terrestrial Radiation 48Introduction 48Blackbody radiation laws 49Radiation exchange for ‘gray’ surfaces 51Integrated radiation parameters for natural surfaces 52Maximum solar radiation at the top of atmosphere 54Maximum solar radiation at the ground 56Atmospheric attenuation of solar radiation 58Actual solar radiation at the ground 59Longwave radiation 59Net radiation at the surface 62Height dependence of net radiation 63Important points in this chapter 646 Soil Temperature and Heat Flux 66Introduction 66Soil surface temperature 66Subsurface soil temperatures 67Thermal properties of soil 68Density of soil, ρs 69Specific heat of soil, cs 70Heat capacity per unit volume, Cs 70Thermal conductivity, ks 70Thermal diffusivity, αs 71Formal description of soil heat flow 71Thermal waves in homogeneous soil 72Important points in this chapter 757 Measuring Surface Heat Fluxes 77Introduction 77Measuring solar radiation 77Daily estimates of cloud cover 77Thermoelectric pyranometers 78Photoelectric pyranometers 79Measuring net radiation 80Measuring soil heat flux 81Measuring latent and sensible heat 82Micrometeorological measurement of surface energy fluxes 83Bowen ratio/energy budget method 83Eddy correlation method 85Evaporation measurement from integrated water loss 87Evaporation pans 88Watersheds and lakes 89Lysimeters 90Soil moisture depletion 91Comparison of evaporation measuring methods 91Important points in this chapter 948 General Circulation Models 96Introduction 96What are General Circulation Models? 96How are General Circulation Models used? 98How do General Circulation Models work? 100Sequence of operations 100Solving the dynamics 102Calculating the physics 103Intergovernmental Panel on Climate Change (IPCC) 104Important points in this chapter 1059 Global Scale Influences on Hydrometeorology 107Introduction 107Global scale influences on atmospheric circulation 107Planetary interrelationship 109Latitudinal differences in solar energy input 109Seasonal perturbations 109Daily perturbations 109Persistent perturbations 109Contrast in ocean to continent surface exchanges 109Continental topography 109Temporary perturbations 110Perturbations in oceanic circulation 110Perturbations in atmospheric content 110Perturbations in continental land cover 110Latitudinal imbalance in radiant energy 110Lower atmosphere circulation 111Latitudinal bands of pressure and wind 111Hadley circulation 112Mean low-level circulation 113Mean upper level circulation 115Ocean circulation 116Oceanic influences on continental hydroclimate 118Monsoon flow 118Tropical cyclones 119El Niño Southern Oscillation 120Pacific Decadal Oscillation 122North Atlantic Oscillation 123Water vapor in the atmosphere 123Important points in this chapter 12610 Formation of Clouds 128Introduction 128Cloud generating mechanisms 129Cloud condensation nuclei 131Saturated vapor pressure of curved surfaces 132Cloud droplet size, concentration and terminal velocity 133Ice in clouds 134Cloud formation processes 135Thermal convection 135Foehn effect 136Extratropical fronts and cyclones 138Cloud genera 140Important points in this chapter 14111 Formation of Precipitation 143Introduction 143Precipitation formation in warm clouds 144Precipitation formation in other clouds 146Which clouds produce rain? 148Precipitation form 149Raindrop size distribution 150Rainfall rates and kinetic energy 151Forms of frozen precipitation 151Other forms of precipitation 152Important points in this chapter 15312 Precipitation Measurement and Observation 155Introduction 155Precipitation measurement using gauges 156Instrumental errors 157Site and location errors 157Gauge designs 160Areal representativeness of gauge measurements 162Snowfall measurement 165Precipitation measurement using ground-based radar 168Precipitation measurement using satellite systems 171Cloud mapping and characterization 171Passive measurement of cloud properties 172Spaceborne radar 173Important points in this chapter 17413 Precipitation Analysis in Time 176Introduction 176Precipitation climatology 177Annual variations 177Intra-annual variations 177Daily variations 180Trends in precipitation 181Running means 182Cumulative deviations 183Mass curve 184Oscillations in precipitation 186System signatures 187Intensity-duration relationships 189Statistics of extremes 190Conditional probabilities 195Important points in this chapter 19614 Precipitation Analysis in Space 198Introduction 198Mapping precipitation 199Areal mean precipitation 200Isohyetal method 200Triangle method 202Theissen method 202Spatial organization of precipitation 203Design storms and areal reduction factors 205Probable maximum precipitation 207Spatial correlation of precipitation 209Important points in this chapter 21115 Mathematical and Conceptual Tools of Turbulence 213Introduction 213Signature and spectrum of atmospheric turbulence 213Mean and fluctuating components 216Rules of averaging for decomposed variables 217Variance and standard deviation 219Measures of the strength of turbulence 220Mean and turbulent kinetic energy 220Linear correlation coefficient 221Kinematic flux 223Advective and turbulent fluxes 225Important points in this chapter 22916 Equations of Atmospheric Flow in the ABL 231Introduction 231Time rate of change in a fluid 232Conservation of momentum in the atmosphere 234Pressure forces 235Viscous flow in fluids 236Axis-specific forces 239Combined momentum forces 242Conservation of mass of air 243Conservation of atmospheric moisture 244Conservation of energy 245Conservation of a scalar quantity 246Summary of equations of atmospheric flow 247Important points in this chapter 24717 Equations of Turbulent Flow in the ABL 248Introduction 248Fluctuations in the ideal gas law 248The Boussinesq approximation 249Neglecting subsidence 250Geostrophic wind 251Divergence equation for turbulent fluctuations 252Conservation of momentum in the turbulent ABL 252Conservation of moisture, heat, and scalars in the turbulent ABL 254Neglecting molecular diffusion 255Important points in this chapter 25818 Observed ABL Profiles: Higher Order Moments 259Introduction 259Nature and evolution of the ABL 259Daytime ABL profiles 261Nighttime ABL profiles 263Higher order moments 265Prognostic equations for turbulent departures 265Prognostic equations for turbulent kinetic energy 269Prognostic equations for variance of moisture and heat 271Important points in this chapter 27619 Turbulent Closure, K Theory, and Mixing Length 277Introduction 277Richardson number 277Turbulent closure 279Low order closure schemes 280Local, first order closure 281Mixing length theory 283Important points in this chapter 28820 Surface Layer Scaling and Aerodynamic Resistance 289Introduction 289Dimensionless gradients 290Obukhov length 292Flux-gradient relationships 293Returning fluxes to natural units 294Resistance analogues and aerodynamic resistance 296Important points in this chapter 29921 Canopy Processes and Canopy Resistances 300Introduction 300Boundary layer exchange processes 301Shelter factors 306Stomatal resistance 308Energy budget of a dry leaf 310Energy budget of a dry canopy 311Important points in this chapter 31422 Whole Canopy Interactions 316Introduction 316Whole-canopy aerodynamics and canopy structure 317Excess resistance 319Roughness sublayer 321Wet canopies 323Equilibrium evaporation 325Evaporation into an unsaturated atmosphere 327Important points in this chapter 33223 Daily Estimates of Evaporation 334Introduction 334Daily average values of weather variables 335Temperature, humidity, and wind speed 335Net radiation 337Open water evaporation 339Reference crop evapotranspiration 341Penman-Monteith equation estimation of ERC 342Radiation-based estimation of ERC 344Temperature-based estimation of ERC 345Evaporation pan-based estimation of ERC 346Evaporation from unstressed vegetation: the Matt-Shuttleworth approach 348Evaporation from water stressed vegetation 353Important points in this chapter 35524 Soil Vegetation Atmosphere Transfer Schemes 359Introduction 359Basis and origin of land-surface sub-models 359Developing realism in SVATS 362Plot-scale, one-dimensional ‘micrometeorological’ models 364Improving representation of hydrological processes 367Improving representation of carbon dioxide exchange 368Ongoing developments in land surface sub-models 370Important points in this chapter 37325 Sensitivity to Land Surface Exchanges 380Introduction 380Influence of land surfaces on weather and climate 381A. The influence of existing land-atmosphere interactions 3831. Effect of topography on convection and precipitation 3832. Contribution by land surfaces to atmospheric water availability 385B. The influence of transient changes in land surfaces 3851. Effect of transient changes in soil moisture 3852. Effect of transient changes in vegetation cover 3883. Effect of transient changes in frozen precipitation cover 3894. Combined effect of transient changes 391C. The influence of imposed persistent changes in land cover 3921. Effect of imposed land cover change on near surface observations 3922. Effect of imposed land-cover change on regional-scale climate 3933. Effect of imposed heterogeneity in land cover 395Important points in this chapter 39826 Example Questions and Answers 404Introduction 404Example questions 404Question 1 404Question 2 405Question 3 407Question 4 408Question 5 410Question 6 411Question 7 412Question 8 414Question 9 416Question 10 418Example Answers 418Answer 1 418Answer 2 420Answer 3 420Answer 4 425Answer 5 426Answer 6 427Answer 7 429Answer 8 432Answer 9 434Answer 10 437Index 441

“Recent research investigations have demonstrated the complexity of land-atmosphere processes, making it necessary for the next generation of scientists to have a multidisciplinary background. Fortunately, the new book by James Shuttleworth, Terrestrial Hydrometeorology, addresses this issue by combining both hydrology and meteorology. This … book is ripe with information, chapter summaries, sample questions and answers, and a companion website with downloadable figures and tables. I will definitely be adding this to my bookshelf, and I recommend students and faculty of all ranks do the same.”  (Groundwater, May-June 2014)“Just as with a well-written PhD thesis, there is not only clarity but boundless enthusiasm which emerges from the pages of this book. It is an enthusiasm which is infectious, and most definitely converts me to this newly invented graduate subject.”  (European Journal of Soil Science, 1 August 2012