Foreword
Preface
1. The earth as an Ecosystem
Spaceship Earth and its ecosystems .............................. 1
The thermal environment of Earth ................................ 3
Feedback in systems ............................................. 6
Earth's atmosphere: composition ................................. 7
Earth's atmosphere: the distribution of mass in the vertical .... 8
Climate and Life on Earth ....................................... 9
Climate and Man ................................................ 11
Box 1-1: An approximate bioclimatic history of Earth ........... 12
2. Energy and Insolation
Energy as the basic link in an ecosystem ....................... 15
Forms of energy ................................................ 16
Heat and its forms ............................................. 16
Heat transfer .................................................. 17
Solar radiation: one form of heat transfer ..................... 19
Solar geometry: the sun and Earth seen from outer space ........ 19
Solar geometry: movement of the sun as seen from Earth ......... 22
Insolation ..................................................... 26
Albedo ......................................................... 30
Box 2-1: The Solar Constant .................................... 32
Box 2-2: Calculations of solar geometry ........................ 33
Box 2-3: Calculations of direct beam solar radiation ........... 35
3. Radiation
Introduction ................................................... 37
Spectra ........................................................ 37
The Black Body ................................................. 38
Radiation terminology .......................................... 38
Planck's Law ................................................... 39
Fundamentals of Blometeorology: I. The Physical Environment
Shortwave and longwave radiation ............................... 42
Wien's Law ..................................................... 43
The Stefan-Boltzmann Law ....................................... 44
Kirchhoff's Law ................................................ 45
Effective, or band, emissivity and absorptivity ................ 41
Emission and Absorption by living leaves ....................... 48
Emission and Absorption by atmospheric gases ................... 50
The Greenhouse Effect .......................................... 51
The radiation inversion: nighttime cooling of air near
Earth's surface ................................................ 51
Radiative properties of natural materials ...................... 53
Energy balance of the Earth-Atmosphere system .................. 54
Box 3-1: Historical note on Black Body radiation laws .......... 57
Box 3-2: Mathematical and graphical forms of Planck's Law
and Wien's Law ................................................. 58
Box 3-3: Effective temperatures and the Greenhouse Effect ...... 63
4. Environmental Temperature
Introduction ................................................... 66
Temperature versus Heat ........................................ 66
Observations of temperature near Earth's surface ............... 68
Temperature and flow of heat in soil and water ................. 72
Temperature and the storage of heat in air and soil ............ 74
The flow and storage of heat in soil ........................... 77
Lapse rates and vertical motion in air ......................... 82
Observations of lapse rates near Earth's surface ............... 85
Box 4-1: Scales of Temperature ................................. 91
Box 4-2: Time and space variability of temperature near
Earth's surface ................................................ 92
Box 4-3: Thermal diffusivity and the dynamics of heat flow
in the soil .................................................... 95
Box 4-4: Mathematical analysis of field observations of air
temperature profiles ........................................... 98
5. Environmental Moisture
Introduction .................................................. 101
Vapor pressure ................................................ 102
The Temperature-Relative Humidity-Vapor Pressure (TRe)
diagram ....................................................... 104
Other measures of atmospheric moisture ........................ 108
Vapor movement in the environment ............................. 108
Moisture lapse rates and profiles just above the surface ...... 111
Principles of evaporation and evapotranspiration .............. 115
Soil moisture: basic considerations ........................... 117
The soil moisture characteristic curve ........................ 120
Soil moisture: liquid or film flow ............................ 120
Soil moisture: vapor flow ..................................... 123
Soil moisture: field conditions ............................... 124
Box 5-1: The latent heat involved in global evaporation ....... 126
Box 5-2: The Saturation Vapor Pressure of water ............... 126
6. Atmospheric Motion
Introduction .................................................. 129
The basic cause of motion ..................................... 129
Circulation cells in the atmosphere ........................... 131
The concept of the boundary layer ............................. 133
Wind profiles, patchiness, and plumes within boundary
layers ........................................................ 134
Windflow around individual obstacles .......................... 136
Windflow in complex terrain ................................... 137
Advection ..................................................... 141
Box 6-1: The variability of wind .............................. 145
7. Structure and Transfer in a Boundary Layer
Introduction .................................................. 150
Turbulence .................................................... 151
Wind profiles ................................................. 154
Turbulent transfer ............................................ 157
Turbulent flux ................................................ 160
The gradient as a measure of source strength .................. 167
Microscale boundary layers .................................... 169
Concluding remarks ............................................ 172
Box 7-1: Mathematical analysis of field observations on
wind speed profiles ........................................... 173
Box 7-2: Turbulent flux by eddy correlation ................... 179
Box 7-3: The aerodynamic and gradient methods for
estimating flux ............................................... 181
Box 7-4: Richardson's number and the effects of buoyancy
on flux ....................................................... 182
8. Structure and Transfer in a Canopy Layer
Introduction .................................................. 185
Canopy structure: the Leaf Area Index (LAI) ................... 185
Canopy profiles: wind speed ................................... 189
Canopy profiles: radiation .................................... 191
Canopy profiles: temperature .................................. 193
Canopy profiles: water vapor .................................. 194
Canopy profiles: carbon dioxide ............................... 194
Profile, flux, and source strength ............................ 195
Canopy resistance ............................................. 197
Box 8-1: Extinction and transmissivity in a canopy ............ 200
Box 8-2: Gradient, diffusivity, and flux in a vegetative
canopy ........................................................ 202
Box 8-3: Series and parallel resistances in circuits .......... 203
9. The Energy Balance Concept
Introduction .................................................. 206
Terminology ................................................... 207
Motivation for studies of energy balance ...................... 208
The temperature of a system ................................... 208
Four types of energy balance system ........................... 211
The radiation budget and net radiation ........................ 213
Energy Balance Type 1: observed variability of components ..... 217
Energy Balance Type 1: estimation of components ............... 223
Energy Balance Type 1: nature and effects of the soil heat
flux, B ....................................................... 225
Energy Balance Type 2: observed variability of components ..... 230
Energy Balance Type 2: estimation of components ............... 234
Box 9-1: Mathematical expression of the energy balance
system ........................................................ 236
Box 9-2: Calculations of the sensible and latent heat fluxes
above Type 1 and Type 2 energy balance systems ................ 239
Box 9-3: The surface temperature as a dependent variable in
a Type 1 energy balance system ................................ 240
Appendices
A. Use of Sun Path Diagrams ................................... 244
B. Physical Units and Conversions ............................. 248
C. The Greenhouse Effect Debates .............................. 251
D. An Overview of Micrometeorological Instrumentation ......... 263
E. Mathematical Proofs and Derivations ........................ 272
References .................................................... 275
Mathematical Symbols .......................................... 279
Problems ...................................................... 289
Author Index .................................................. 298
Subject Index ................................................. 300
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