Advances in Geophysics (eBook)

Front Cover 1
Advances in Geophysics: Issues in Atmospheric and Oceanic Modeling, Volume 28 4
Copyright Page 5
Contents 6
Contributors 10
Foreword 12
Preface 16
Part I: Numerical Weather Prediction 18
Chapter 1. Mediurn-Range Forecasting at the ECMWF 20
1. Introduction 20
2. The Physical and Mathematical Basis for Medium-Range Forecasting 22
3. Numerical Methods and Modeling Technique 24
4. Observations, Their Use and Importance 32
5. Operational Application and Results 41
6. Problems and Prospects in Numerical Weather Prediction 52
7. Concluding Remarks 67
References 68
Chapter 2. Extended Range Forecasting 72
1. Introduction 72
2. An Evolution of 10-Day Forecast Performance 73
3. Examples of Monthly Forecasts 82
4. A Projection of Seasonal Forecasts 96
5. Postscript 99
References 100
Chapter 3. Predictability 104
1. Introduction 104
2. Classical Predictability Studies 106
3. Predictability of Space-Time Averages 127
4. Some Outstanding Problems 133
5. Concluding Remarks 136
References 138
Chapter 4. Data Assimilation 140
1. Introduction 140
2. Evolution of Assimilation and the FGGE 142
3. Components of Four-Dimensional Assimilation Systems 148
4. Characteristics of Some Current Assimilation Schemes 155
5. Role of Four-Dimensional Assimilation in Research and Operations 160
6. Conclusion 168
References 168
Part II: Mesoscale Dynamics 174
Chapter 1. Predictability of Mesoscale Atmospheric Motions 176
1. Introduction 176
2. Classic Predictability Experiments and Their Relationship to Mesoscale Predictability 181
3. Preliminary Predictability Study with a Mesoscale Model 182
4. Discussion and Comparison with a Predictability Study Using a Global Model 212
5. Summary and Conclusions 215
References 217
Chapter 2. Thermal and Orographic Mesoscale Atmospheric Systems—An Essay 220
1. Introduction 220
2. Summary of Major Research Accomplishments 221
3. Research Areas 233
4. Eventual Goals 235
References 236
Chapter 3. Advances in the Theory of Atmospheric Fronts 240
1. Introduction 240
2. Baroclinic Waves and Fronts 242
3. Mature Front 246
4. What Observed Features Can Be Explained by Theory? 250
5. What Other Processes Are Important in Frontogenesis? 254
References 267
Part Ill: Tropical Dynamics 270
Chapter 1. Numerical Modeling of Tropical Cyclones 272
1. Introduction 272
2. Numerical Models of Hurricanes 273
3. Numerical Simulation of Tropical Cyclones 278
4. Some Challenging Issues in the Future 293
Appendix. GFDL Hurricane Models 295
References 297
Chapter 2. Numerical Weather Prediction in Low Latitudes 300
1. Introduction 300
2. Initialization: Dynamic, Normal Mode, and Physical 308
3. Parameterization of Physical Processes 323
4. Medium-Range Prediction of Monsoon Disturbances 331
5. On the Prediction of the Quasi-Stationary Component 340
6. Scope of Future Research 347
References 348
Part IV: Turbulence and Convection 352
Chapter 1. Sub-Grid-Scale Turbulence Modeling 354
1. Introduction: The Need for Grid-Scale Reynolds Averaging 354
2. The Effect of Grid-Volume Reynolds Averaging 355
3. The Sub-Grid-Scale Eddy Coefficient 357
4. Recent Developments 358
5. Future Outlook 358
References 359
Chapter 2. Ensemble Average, Turbulence Closure 362
1. Introduction 362
2. The Turbulence Macroscale and Turbulence Closure 364
3. Averaging Distance for Measurements in the Atmosphere and Oceans and for Numerical Models 371
4. Numerical Modeling Applications and Horizontal Diffusion 372
5. Concluding Remarks 373
References 374
Chapter 3. The Planetary Boundary Layer 376
1. General Characteristics 376
2. The Equations in the PBL 381
3. The Surface Layer 384
4. First- and Second-Order Closures 394
5. Boundary-Layer Models 397
6. Boundary-Layer Parameterization 400
References 400
Chapter 4. Modeling Studies of Convection 404
1. Introduction 404
2. Bénard–Rayleigh Convection 405
3. Complexity of Convection in the Atmosphere 408
4. Shallow Moist Convection 409
5. Deep Moist Convection 414
6. Feedback Effects of Cumulus Clouds on Larger-Scale Environments 425
7. Concluding Remarks 430
References 433
Index 440