Atmosphere and Climate (eBook)

Preface 5
Table of Contents 7
Radio Occultation with CHAMP 11
GPS Radio Occultation with CHAMP and 12
GRACE: Recent Results 12
1 Introduction 12
2 Status of the CHAMP RO Experiment 13
3 Operational Data Analysis 14
4 Recent Validation Results for CHAMP 16
5 Monitoring of Tropopause Parameters 18
6 First Results from GRACE 19
7 Atmospheric Sounding with CHAMP and GRACE 21
8 Conclusions and Outlook 21
References 22
Sensitivity of Stratospheric Retrievals from 26
Radio Occultations on Upper Boundary 26
Conditions 26
1 Introduction 26
2 Data and Methodology 27
3 Simulation Results 30
4 Conclusion 33
References 34
Refractivity Biases in GNSS Occultation Data 46
1 Introduction 46
2 Data Analysis and Discussion 47
3 Conclusions 51
References 51
Stellar Occultation with GOMOS 53
GOMOS Ozone Pro.les at High Latitudes: 54
Comparison with Marambio and Sodankyl¨ a 54
Sonde Measurements 54
1 Introduction 54
2 Co-Locating Measurements 55
3 Comparing GOMOS with Ozone Soundings 55
4 Summary 59
References 60
Ozone and Temperature Retrieval Results 62
from GOMOS Validated with CHAMP and 62
ECMWF 62
1 Introduction 62
2 GOMOS Retrieval Schemes 63
3 Retrieval Results 66
4 Summary and Conclusions 71
References 71
Modeling Errors of GOMOS Measurements: A 74
Sensitivity Study 74
1 Introduction 74
2 GOMOS Inversion 75
3 Error Estimates of GOMOS Products 77
4 Identi.cation of Problems in Modeling Error 77
Characterization 77
5 Modeling Errors of GOMOS Measurements 78
6 Discussion and Summary 82
References 84
Wave Optics Algorithms for the Processing of Radio Occultation Data 86
Asymptotic Wave Optics Methods in Inversion 87
and Direct Modeling of Radio Occultations: 87
Recent Achievements 87
1 Introduction 87
2 Basic Principles of Fourier Integral Operators 88
3 Processing Radio Occultations 92
4 Forward Modeling 94
5 Conclusions 98
References 99
Radio Holographic Filtering of 132
Noisy Radio Occultations 132
1 Introduction 132
2 Inversion of Data Without Noise 133
3 Phase Models 134
4 Radio Holographic Noise Filtering 135
5 Inversion of Noisy Data 136
6 Conclusions 137
References 138
Future GNSS Occultation Missions and the LEO- LEO Occultation Concept 140
Preparing for COSMIC: Inversion and Analysis 141
of Ionospheric Data Products 141
1 Introduction 141
2 Ionospheric Data Products 142
3 Ionospheric Pro.les from Occultations 143
4 Combining TIP and Occultation Data 144
5 Ionospheric Scintillations 146
6 Ionospheric Tomography and Assimilation 147
7 Summary 148
References 149
The Operational EPS GRAS Measurement 151
System 151
1 GRAS Product Requirements 151
3 GRAS Level 1 Data Processing 155
4 GRAS Level 1 Product Validation 159
5 Summary 159
References 160
Processing X/K Band Radio Occultation Data 186
in Presence of Turbulence: An Overview 186
1 Introduction 186
2 Description of Method 188
3 Numerical Simulations 189
4 Conclusions and Outlook 191
References 194
Use of GNSS Occultation Data in Numerical Weather Prediction and in Atmospheric Studies 196
Assimilation of GNSS Radio Occultation Data 197
into Numerical Weather Prediction 197
1 Introduction 197
2 Modeling the Weather 198
3 Assimilation of GNSS RO Data for NWP 200
4 Review of GNSS RO Impact Studies on NWP 202
5 Prospects for Impact 203
6 Conclusion 205
References 205
Observation Operators for the Assimilation of 207
Occultation Data Into Atmospheric Models: A 207
Review 207
1 Introduction 207
2 Assimilating Which Data Product? 208
3 Simple Observation Operators 210
4 Two-Dimensional Ray Tracing Operators 213
5 Advanced Alternatives to Ray Tracing 215
6 Summary and Prospects 221
References 222
Are we Observing Mountain Waves Above the 244
Andes Range from GPS Occultation Pro.les? 244
1 Introduction 244
2 GPS RO Data and Analysis 245
References 253
Analysis of Seasonal and Daily Mid-Latitude 254
Tropopause Pressure Using GPS Radio 254
Occultation Data and NCEP-NCAR 254
Reanalyses 254
1 Introduction 255
2 Data and Method 256
3 Results 258
4 Conclusions and Comments 261
References 263
CHAMP Radio Occultation Detection of the 265
Planetary Boundary Layer Top 265
1 Introduction 265
2 Data Processing 266
3 Results 268
4 Conclusion 270
References 271
Use of GNSS Occultation Data for Climate Monitoring and Climate Change Studies 273
Climate Benchmarking Using GNSS 285
Occultation 285
1 Introduction 285
2 An Overview of Climate Monitoring 286
3 Bayesian Inference and Climate Signal Detection 288
4 Climate Model Uncertainties and How They are 290
Realized in Microwave Refractivity 290
5 Benchmarking GNSS Occultation 296
References 298
Global Climatologies Based on Radio Occultation Data: The CHAMPCLIM Project 300
1 Introduction 300
2 Properties of Radio Occultation Data 301
3 Atmospheric Parameters for Climate Monitoring 303
4 The CHAMPCLIM Project 304
5 Seasonal CHAMP Dry Temperature Climatologies 305
6 Concluding Remarks 308
References 309
Pre-Operational Retrieval of Radio Occultation Based Climatologies 312
1 Introduction 312
2 Pre-Operational Retrieval Status 313
3 Setup of Climatologies 315
4 Conclusions and Outlook 318
References 319
Assimilation of GNSS Radio Occultation Profiles into GCM Fields for Global Climate Analysis 321
1 Introduction 321
2 3D-Var System Implementation 322
3 Error Formulation 326
4 First Results 327
5 Conclusion 328
References 330
Author Index 331