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Microwave Remote Sensing of Sea Ice

Microwave Remote Sensing of Sea Ice

Frank D. Carsey (Editor)

ISBN: 978-1-118-66395-0

Mar 2013, American Geophysical Union

462 pages

Select type: O-Book

Description

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 68.

Human activities in the polar regions have undergone incredible changes in this century. Among these changes is the revolution that satellites have brought about in obtaining information concerning polar geophysical processes. Satellites have flown for about three decades, and the polar regions have been the subject of their routine surveillance for more than half that time. Our observations of polar regions have evolved from happenstance ship sightings and isolated harbor icing records to routine global records obtained by those satellites. Thanks to such abundant data, we now know a great deal about the ice-covered seas, which constitute about 10% of the Earth's surface. This explosion of information about sea ice has fascinated scientists for some 20 years. We are now at a point of transition in sea ice studies; we are concerned less about ice itself and more about its role in the climate system. This change in emphasis has been the prime stimulus for this book.
Chapter 1. Introduction 1
1.1 Sea Ice  1
1.2 Sea Ice in Climate and Operations 3
1.3 The Sea Ice Variables 3
1.4 Ice Extent  3
1.5 The Microwave Properties of Ice  3
1.6 Technology Development 4
1.7 Instruments in Orbit, Data Sets in Hand  6
1.8 The Book  6

Chapter 2. Physical Properties of Sea Ice Relevant to Remote Sensing  9
2.1 introduction  9
2.2 First-Year Ice  10
2.3 Evolution of Multiyear Ice 14
2.4 Surface Properties 20
2.5 Snow Cover 23
2.6 Ice Property Statistics 24
2.7 Summary  26

Chapter 3. The Physical Basis for Sea Ice Remote Sensing 29
3.1 Definition of Electromagnetic Quantities 29
3.2 Dielectric and Extinction Properties of the Water-Ice-Snow System 30
3.4 Summary  44

Chapter 4. Passive Microwave Signatures of Sea Ice 47
4.1 Introduction 47
4.2 Sensors 48
4.3 Passive Microwave Signatures of Sea Ice 48
4.4 Sea Ice Features 59
4.5 Mediating Effects 62
4.6 Lake Ice and River Ice 67
4.7 Unresolved Issues 68

Chapter 5. SAR and Scatterometer Signatures of Sea Ice 73
5.1 Introduction  73
5.2 Scattering Measurements 74
5.3 Importance of Environmental and Physical Properties  82
5.4 Ice Type Backscatter Summary 89
5.5 SAR Observations  93
5.6 SAR-Scatterometer Comparisons 98
5.7 Optimum Frequency, Polarization, and Incidence Angle 98
5.8 Radar Lookup Table for ASF GPS 100
5.9 Future Opportunities and Issues  102

Chapter 6. Digital SAR Image Formation 105
6.1 Introduction  105
6.2 Digital Image Formation 105
6.3 Postimage Formation Considerations 109

Chapter 7. Sea Ice Altimetry 111
7.1 Introduction  111
7.2 Instrument Description 111
7.3 Sea Ice Scattering Models at Normal Incidence 116
7.4 Theory Versus Measurement  121
7.5 Summary 132

Chapter 8. Microwave Sea Ice Signature Modeling 137
8.1 Introduction  137
8.2 Overview of Signature Models 139
8.3 Case Study 1: A Thin Gray Ice Sheet 150
8.4 Case Study 2: Cold Old Ice 162
8.5 Conclusions171

Chapter 9. Laboratory Investigations of the Electromagnetic Properties of Artificial Sea Ice 177
9.1 Introduction  177
9.2 Scope  178
9.3 Growth Phase of Thin Saline Ice  183
9.3.1 Thin Ice Data interpretation 186
9.4 Urea ice  188
9.5 Desalinated Ice  190
9.6 Pancake Ice  192
9.7 Surface Effects  193
9.7.1 Roughened Surface 193
9.7.2 Rubble Surface  193
9.7.3 Snow-Covered Surface  195
9.8 Significance of CRRELEX Results 199

Chapter 10. The Estimation of Geophysical Parameters Using Passive Microwave Algorithms  201
10.1 Introduction  201
10.2 Ice Type and Concentration  203
10.3 Ice Temperature 224
10.4 Summary and Outlook 228

Chapter 11. The Validation of Geophysical Products Using Multisensor Data 233
11.1 Introduction  233
11.2 Validation Data Sets  233
11.3 Sea Ice Product Accuracy 234
11.3.1 Ice Extent  234
11.3.2 Ice Concentration  235
11.3.3 Ice Type 237
11.4 Future Requirements 239

Chapter 12. Microwave Remote S ensing of the Southern Ocean I ce Cover 243
12.1 Introduction  24
12.2 The Ice Regimes - Outer and Inner Zones 244
12.3 Physical and Electrical Characteristics of Antarctic Sea Ice 245
12.4 Radiative and Backscatter Properties  247
12.5 Derived Geophysical Parameters 250
12.6 Discussion and Conclusion 258

Chapter 13. Microwave Study Programs of Air-Ice-Ocean Interactive Processes in the Seasonal Ice Zone of the Greenland and Barents Seas  261
13.1 Introduction  261
13.2 Campaigns 263
13.3 ModelingS easonal Ice Zone Processes 280
13.4 Regional Forecasting Using Microwave Observations  282
13.5 The SIZ in the Climate System 284

Chapter 14. Considerations for Microwave Remote Sensing of Thin Sea Ice 291
14.1 Introduction  291
14.2 Terminology and Classification 292
14.3 Geographical and Temporal Distribution of Thin Ice 293
14.4 Microwave Signatures of Thin Ice  294
14.5 Implications for Satellite Algorithms 299
14.6 Potential for Multisensor Data  300
14.7 Future Directions  300

Chapter 15. Microwave Remote Sensing of Polynyas 303
15.1 Introduction 303
15.2 Microwave Detection and Mapping of Polynyas: Limitations and Potential  305
15.3 The Oceanographica nd Climate Role of Polynyas 305
15.4 Future Directions  309

Chapter 16. Characterization of Snow on Floating Ice and Case Studies of Brightness Temperature Changes During the Onset of Melt 313
16.1 Background 313
16.2 Introduction  313
16.3 Method of Measurements  314
16.4 Evolution of a Snow Cover 315
16.5 Case Studies of BrightnessT emperature From Snow on Floating Ice 322
16.7 A Descriptive Metamorphism Model of Homogeneous Snow for Passive Microwave Sensing 325
16.8 Conclusion 326

Chapter 17. The Effects of Freeze-Up and Melt Processes on Microwave Signatures 329
17.1 Introduction 329
17.2 Physical and Electrical Properties of the Ice During the Melt Season 329
17.3 Summary of Research Results  330
17.4 Conclusions  340

Chapter 18. Determination of Sea Ice Motion From Satellite Images 343
18.1 Introduction 343
18.2 Ice Motion and Observations  343
18.3 Ice Tracking TechniquesU sing Satellite Imagery 348
18.4 An Ice Motion Algorithm 351
18.5 Outlook  351

Chapter 19. An Approach to Identification of Sea Ice Types From Spaceborne SAR Data 355
19.1 Introduction 355
19.2 Ice Classification Approach 355
19.3 Data Set and Simulation 355
19.4 Results 358
19.5 Discussion  359

Chapter 20. Microwave Remote Sensing of Low-Salinity Sea Ice 361
20.1 Introduction  361
20.2 Characteristics of Low-Salinity Sea Ice 361
20.3 Microwave Remote Sensing Experiments in the Baltic Sea 361
20.4 Active Remote Sensing of Sea Ice 364
20.5 Passive Remote Sensing 368
20.6 Summary 371

Chapter 21. The Ice Thickness Distribution Inferred Using Remote Sensing Techniques 375
21.1 Introduction  375
21.2 Direct Techniques for Estimating Ice Thickness Distribution 375
21.3 Indirect Remote Sensing Techniques 378
21.4 Discussion and Conclusions  381

Chapter 22. The Use of Satellite Observationsin Ice Cover Simulations 385
22.1 Introduction  385
22.2 Numerical Models  385
22.3 Model Requirements of Satellite Data 390
22.4 Examples of the Interaction of Models with Data 394
22.5 Summary and Conclusions 398

Chapter 23. Ice Modeling and Data Assimilation Using the Kalman Smoother  405
23.1 Introduction 405
23.2 Concepts 406
23.3 Results 410
23.4 Conclusions aned Outlook  417

Chapter 24. Potential Applications of Polarimetry to the Classification of Sea Ice 419
24.1 Introduction 419
24.2 Polarimetric Data and Definitions 419
24.3 Polarimetric Discriminants  420
24.4 Geophysical Applications of Polarimetry 425
24.5 Discussion  428

Chapter 25. Information Fusion in Sea Ice Remote Sensing 431
25.1 Introduction  431
25.2 The Need for Multitype Information  431
25.3 A Simple Model of Information Fusion  431
25.4 Representation  432
25.5 Inference  432
25.6 Expert Systems 437
25.7 Conclusions  438

Chapter 26. Status and Future Directions for Sea Ice Remote Sensing 443
26.1 Summary  443
26.2 Future Directions 444
26.3 Sea Ice in the Context of Global Change  445
26.4 Applications of Satellite Data Products  445
26.5 Conclusion  446

Appendix A . Glossaryo f Ice Terminology 447

Appendix B. Archive Satellite Data 451

Acronyms and Abbreviations 453

Index 457