Climate Change and Climate Modeling

Cover......Page 1
Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication......Page 7
Contents......Page 9
Preface......Page 15
1.1 Climate dynamics, climate change and climate prediction......Page 19
1.2.1 Chemical and physical aspects of the climate system......Page 21
1.2.2 El Nino and global warming......Page 22
1.3 Climate models: a brief overview......Page 23
1.4.1 Trace gas concentrations......Page 25
1.4.3 Some history of global warming studies......Page 28
1.4.4 Global temperatures......Page 30
1.5 El Nino: an example of natural climate variability......Page 31
1.5.1 Some history of El Nino studies......Page 32
1.5.2 Observations of El Nino: the 1997–98 event......Page 37
1.5.3 The first El Nino forecast with a coupled ocean–atmosphere model......Page 40
1.6 Paleoclimate variability......Page 42
Notes......Page 47
2.1 Components and phenomena in the climate system......Page 52
2.1.1 Time and space scales......Page 53
2.1.2 Interactions among scales and the parameterization problem......Page 55
2.2.1 Blackbody radiation......Page 59
2.2.2 Solar energy input......Page 62
2.3 Globally averaged energy budget: first glance......Page 64
2.4 Gradients of radiative forcing and energy transports......Page 66
2.5.1 Vertical structure......Page 68
2.5.2 Latitude structure of the circulation......Page 69
2.5.3 Latitude–longitude dependence of atmospheric climate features......Page 72
2.6.1 Latitude–longitude dependence of oceanic climate features......Page 76
2.6.2 The ocean vertical structure......Page 78
2.6.3 The ocean thermohaline circulation......Page 80
2.7 Land surface processes......Page 81
2.8 The carbon cycle......Page 82
Notes......Page 87
3.1 Conservation of momentum......Page 89
3.1.1 Coriolis force......Page 90
3.1.2 Pressure gradient force......Page 92
3.1.4 Application: geostrophic wind......Page 93
3.1.6 Application: pressure coordinates......Page 94
3.2.2 Equation of state for the ocean......Page 95
3.2.3 Application: atmospheric height–pressure–temperature relation......Page 96
3.2.4 Application: thermal circulations......Page 97
3.2.5 Application: sea level rise due to oceanic thermal expansion......Page 98
3.3.2 Temperature equation for air......Page 99
3.3.3 Application: the dry adiabatic lapse rate near the surface......Page 100
3.3.4 Application: decay of a sea surface temperature anomaly......Page 101
3.3.5 Time derivative following the parcel......Page 102
Conservation of mass......Page 103
3.4.2 Atmospheric continuity equation......Page 104
3.4.3 Application: coastal upwelling......Page 105
3.4.5 Application: conservation of warm water mass in an idealized layer above the thermocline......Page 106
3.5.1 Moisture equation for the atmosphere and surface......Page 107
3.5.2 Sources and sinks of moisture, and latent heat......Page 108
3.5.4 Salinity equation for the ocean......Page 109
3.6.1 Saturation......Page 110
3.6.2 Saturation in convection; lifting condensation level......Page 111
3.6.4 Moist convection......Page 112
3.7.1 Gravity waves......Page 113
3.7.3 Rossby waves......Page 114
3.8 Overview......Page 116
Notes......Page 119
4.1.1 The Bjerknes hypothesis......Page 121
4.2 Tropical Pacific climatology......Page 122
4.3 ENSO mechanisms I: extreme phases......Page 124
4.4 Pressure gradients in an idealized upper layer......Page 126
4.4.1 Subsurface temperature anomalies in an idealized upper layer......Page 127
4.5.1 Subsurface temperature measurements......Page 128
4.5.2 Subsurface temperature anomalies during the onset of El Nino......Page 129
4.5.3 Subsurface temperature anomalies during the transition to La Niña......Page 133
4.6 El Nino mechanisms II: dynamics of transition phases......Page 134
4.6.1 Equatorial jets and the Kelvin wave......Page 135
4.6.2 The Kelvin wave speed......Page 137
4.6.3 What sets the width of the Kelvin wave and equatorial jet?......Page 138
4.6.4 Response of the ocean to a wind anomaly......Page 139
4.6.5 The delayed oscillator model and the recharge oscillator model......Page 141
4.6.6 ENSO transition mechanism in brief......Page 142
4.7 El Nino prediction......Page 143
4.7.1 Limits to skill in ENSO forecasts......Page 145
4.8 El Nino remote impacts: teleconnections......Page 149
4.9.1 Hurricane season forecasts......Page 154
4.9.2 Sahel drought......Page 158
4.9.3 North Atlantic oscillation and annular modes......Page 159
5.1.1 An atmospheric model......Page 163
5.1.2 Treatment of sub-grid-scale processes......Page 165
5.1.3 Resolution and computational cost......Page 167
5.1.4 An ocean model and ocean–atmosphere coupling......Page 170
5.1.5 Land surface, snow, ice and vegetation......Page 172
5.1.6 Summary of principal climate model equations......Page 174
5.1.7 Climate system modeling......Page 175
5.2.1 Finite-difference versus spectral models......Page 176
5.2.2 Time-stepping and numerical stability......Page 179
5.2.3 Staggered grids and other grids......Page 181
5.2.4 Parallel computer architecture......Page 183
5.3.1 Mixing and surface fluxes......Page 184
5.3.2 Dry convection......Page 186
5.3.3 Moist convection......Page 187
5.3.4 Land surface processes and soil moisture......Page 189
5.3.5 Sea ice and snow......Page 190
5.4 The hierarchy of climate models......Page 193
5.5 Climate simulations and climate drift......Page 195
5.6.1 Atmospheric model climatology from specified SST......Page 197
5.6.2 Climate model simulation of climatology......Page 199
5.6.3 Simulation of ENSO response......Page 206
Notes......Page 209
6.1.1 Global energy balance......Page 211
6.1.3 Infrared emissions from a layer......Page 212
6.1.4 The greenhouse effect: example with a completely IR-absorbing atmosphere......Page 213
6.1.5 The greenhouse effect in a one-layer atmosphere, global-average model......Page 214
6.1.6 Temperatures from the one-layer energy balance model......Page 215
6.2.1 Increases in the basic greenhouse effect......Page 216
6.2.2 Climate feedback parameter in the one-layer global-average model......Page 217
6.3 Climate feedbacks......Page 219
6.3.1 Climate feedback parameter......Page 220
6.3.2 Contributions of climate feedbacks to global-average temperature response......Page 221
6.3.3 Climate sensitivity......Page 222
6.4 The water vapor feedback......Page 223
6.5 Snow/ice feedback......Page 225
6.6 Cloud feedbacks......Page 226
6.7.1 Stratospheric cooling......Page 228
6.8.1 Transient climate change versus equilibrium response experiments......Page 229
6.8.3 The role of the oceans in slowing warming......Page 233
6.8.4 Climate sensitivity in transient climate change......Page 235
Notes......Page 237
7.1.1 Scenarios, forcings and feedbacks......Page 239
7.1.3 Commonly used scenarios......Page 240
7.2 Global-average response to greenhouse warming scenarios......Page 243
7.3 Spatial patterns of warming for time-dependent scenarios......Page 247
7.3.1 Comparing projections of different climate models......Page 250
7.3.2 Multi-model ensemble averages......Page 253
7.3.3 Polar amplification of warming......Page 255
7.4.1 Sea ice and snow......Page 256
7.4.2 Land ice......Page 258
7.4.3 Extreme events......Page 261
7.5 Summary: the best-estimate prognosis......Page 262
7.6.1 Temperature trends and natural variability: scale dependence......Page 264
7.6.2 Is the observed trend consistent with natural variability or anthropogenic forcing?......Page 266
7.6.3 Sea ice, land ice, ocean heat storage and sea level rise......Page 268
7.7 Emissions paths and their impacts......Page 270
7.8 The road ahead......Page 274
Notes......Page 278
Glossary......Page 281
References......Page 285
Index......Page 298