Parameterization Schemes: Keys to Understanding Numerical Weather Prediction Models

Cover......Page 1
PARAMETERIZATION SCHEMES: KEYS TO UNDERSTANDING NUMERICAL WEATHER PREDICTION MODELS......Page 3
PARAMETERIZATION SCHEMES: Keys to Understanding Numerical Weather Prediction Models......Page 5
©......Page 6
Dedication......Page 7
Contents......Page 9
Preface......Page 13
List of principal symbols and abbreviations......Page 17
1.1 Introduction......Page 21
1.2 Model improvements......Page 23
1.3 Motivation......Page 27
1.4 Question......Page 31
2.1 Introduction......Page 32
2.2 Overview of the surface energy budget......Page 34
2.2.1 Incoming solar radiation (QS)......Page 35
2.2.2 Albedo (a)......Page 37
2.2.3 Longwave upwelling radiation (QLu)......Page 40
2.2.6 Latent heat flux (QE)......Page 41
2.3.1 Incoming solar radiation......Page 43
2.3.3 Downwelling longwave radiation......Page 45
2.4 Sensible heat flux......Page 48
2.5 Latent heat flux......Page 62
2.5.1 Moisture availability......Page 65
2.5.2 Penman–Monteith approach......Page 66
2.6 Ground heat flux......Page 68
2.6.1 Frozen soil......Page 73
2.7 Surface energy budget equation......Page 75
2.8 Representation of terrain......Page 76
2.9 Discussion......Page 78
2.10 Questions......Page 80
3.1.1 Biophysical control of evapotranspiration......Page 83
3.1.3 Soil moisture availability......Page 85
3.2 Describing vegetation in models......Page 86
3.3 Describing soils in models......Page 95
3.4.1 Bare soil evaporation......Page 100
3.4.2 Canopy water evaporation......Page 104
3.4.3 Transpiration from vegetation......Page 105
3.4.4 Subgrid variability......Page 111
3.5 Momentum transfer......Page 112
3.6 Soil moisture availability......Page 113
3.7 Radiation......Page 127
3.9 Discussion......Page 129
3.10 Questions......Page 137
4.1 Introduction......Page 140
4.2 Observing sea surface temperature......Page 144
4.3 Sensible heat flux......Page 147
4.4 Latent heat flux......Page 153
4.6 Discussion......Page 155
4.7 Questions......Page 157
5.1 Introduction......Page 158
5.2 Reynolds averaging......Page 166
5.3 Turbulence closure......Page 167
5.4 Non-local closure schemes......Page 171
5.4.1 Mixed layer schemes......Page 172
5.4.2 Penetrative convection scheme......Page 177
5.4.3 Non-local diffusion scheme......Page 179
5.5.1 First-order closure scheme......Page 184
5.5.2 1.5-order local closure scheme......Page 189
5.5.3 Second-order closure scheme......Page 192
5.6 Turbulence and horizontal diffusion......Page 195
5.7 Discussion......Page 196
5.8 Questions......Page 201
6.1 Introduction......Page 205
6.2 Influences of deep convection on the environment......Page 213
6.3 Deep-layer control convective schemes......Page 221
6.3.1 Arakawa–Schubert convective scheme......Page 222
6.3.2 Betts–Miller convective scheme......Page 229
6.3.3 Kuo convective scheme......Page 244
6.4 Low-level control convective schemes......Page 247
6.4.1 Mass flux convective schemes......Page 249
6.4.2 Tiedtke convective scheme......Page 251
6.4.3 Gregory–Rowntree convective scheme......Page 253
6.4.4 Kain–Fritsch convective scheme......Page 257
6.4.5 Emanuel convective scheme......Page 266
6.6 Trigger functions......Page 269
6.7 Discussion......Page 270
6.8 Questions......Page 278
7.1 Introduction......Page 280
7.2.1 Cloud droplets......Page 285
7.2.2 Raindrops......Page 288
7.2.3 Ice crystals and aggregates......Page 290
7.2.4 Rimed ice particles, graupel, and hail......Page 292
7.3 Particle size distributions......Page 294
7.4 Bulk microphysical parameterizations......Page 295
7.4.1 Condensation......Page 299
7.4.2 Autoconversion......Page 301
7.4.3 Accretion......Page 303
7.4.4 Evaporation......Page 306
7.4.5 Ice initiation......Page 308
7.4.6 Ice and snow aggregation......Page 310
7.4.7 Accretion by frozen particles......Page 311
7.4.8 Deposition......Page 313
7.4.9 Melting......Page 315
7.5 Discussion......Page 317
7.6 Questions......Page 324
8.1 Introduction......Page 326
8.2 Basic concepts......Page 329
8.2.1 Blackbody radiation......Page 330
8.2.2 Radiative transfer......Page 332
8.3.1 Empirical methods......Page 335
8.3.2 Two-stream methods for clear skies......Page 336
8.3.3 Narrow-band models......Page 340
8.3.4 Wide-band models (emissivity models)......Page 342
8.4.1 Empirical methods......Page 346
8.4.2 Two-stream methods in clear skies......Page 349
8.4.3 Eddington approach......Page 351
8.4.5 Two-stream approach......Page 353
8.5 Radiative transfer data sets......Page 355
8.6 Discussion......Page 357
8.7 Questions......Page 363
9.1 Introduction......Page 366
9.2.1 Diagnostic cloud cover......Page 369
9.2.2 Prognostic cloud cover......Page 373
9.3.1 Longwave radiation in cloudy skies......Page 380
9.3.2 Shortwave radiation in cloudy skies......Page 385
9.4 Discussion......Page 387
9.5 Questions......Page 391
10.1 Introduction......Page 393
10.2 Simple theory......Page 395
10.3 Gravity wave drag parameterizations......Page 404
10.4 Low-level blocking drag parameterizations......Page 407
10.5 Discussion......Page 408
10.6 Questions......Page 412
11.1 Introduction......Page 413
11.2 Ensemble predictions......Page 415
11.3 Ensembles and high-resolution single forecasts......Page 421
11.4 Statistical postprocessing......Page 423
11.5 The road forward......Page 425
References......Page 428
Index......Page 469