Sea Ice

Mohammed Shokr is a Retired Senior Scientist at the Meteorological Research Division of Environment and Climate Change Canada. He is a senior member of IEEE Geoscience and Remote Sensing Society. He spent his scientific career studying sea ice physics and remote sensing. Nirmal K. Sinha is a Retired Senior Scientist at the Institute for Aerospace Research, National Research Council of Canada. He is an expert on engineering physics and optics. He has recently published another book with Wiley, titled Engineering Physics of High-temperature Material: Metals, Ice, Rocks, and Ceramics.

• Preface xvAcknowledgments and Recognitions xvii1 Introduction 11.1 Background 11.2 Canada and the Arctic: Historical and Community Synopsis 41.3 The Fascinating Nature of Sea Ice 81.4 Sea Ice in Research and Operational Disciplines 121.4.1 Sea Ice in Physics 121.4.2 Sea Ice in Climatology 131.4.3 Sea Ice in Meteorology 141.4.4 Sea Ice in Oceanography 151.4.5 Sea Ice in Marine Biology 161.4.6 Sea Ice in Marine Navigation 171.4.7 Sea Ice and Offshore Structures 191.4.8 Sea Ice as A Transportation Platform 201.4.9 Sea Ice in Relation to Solid Earth Sciences: Rocks and Plate Tectonics 211.5 Sea Ice and Remote Sensing 221.6 Motivation for the Book Writing 241.7 Organization of the Book 251.8 References 272 Ice Physics and Physical Processes 292.1 Prior to Freezing: About Freshwater and Seawater 302.1.1 Molecular Composition of Water 302.1.2 Seawater Salinity 312.1.3 Seawater Density 322.2 Phase Diagram of Sea Ice 332.3 Initial Ice Formation 332.3.1 Freezing Processes in Freshwater and Seawater 332.3.2 Initial Formation of Ice Crystals and Frazil Ice 352.4 Sea Ice Growth 372.4.1 Lateral Ice Growth 372.4.2 Vertical Ice Growth (Congelation Ice) 382.4.3 Superimposed Ice 392.4.4 Thermodynamic Ice Growth 402.4.4.1 Simplified Models of Sea Ice Growth 412.4.4.2 Effect of Snow On Sea Ice 452.4.4.3 Effect of Oceanic Heat Flux 462.4.4.4 Effect of Surface Ablation 462.5 Processes in Ice 472.5.1 Compositional (Constitutional) Supercooling At the Ice–Water Interface 502.5.2 Dendritic Ice–Water Interface and Entrapment of Brine Within Sea Ice 512.5.3 Grains and Subgrains In Sea Ice 532.5.4 Brine Pockets Formation, Contents and Distribution In Sea Ice 542.5.5 Salinity Loss During Sea Ice Growth 582.5.5.1 Initial Rapid Salt Rejection At the Ice–Water Interface 592.5.5.2 Subsequent Slow Salt Rejection from the Bulk Ice 612.6 Ice Deformation 672.6.1 Rafting of Thin Ice 692.6.2 Ridging of Thick Ice 702.6.3 Formation of Ice Rubble Field 732.6.4 Fractures in Ice Cover 742.7 Ice Decay and Aging 762.7.1 Ice Decay 762.7.2 Ice Aging 802.8 Sea Ice Classes 842.9 Sea Ice Regimes 852.9.1 Polynyas 862.9.2 Pancake Ice Regime 902.9.3 Marginal Ice Zone and Ice Edge 922.9.3.1 Marginal Ice Zone 932.9.3.2 Ice Edge 942.9.4 Ice of Glacier Origin 952.10 References 993 Sea Ice Properties: Data and Derivations 1073.1 Typical Values of Sea Ice and Snow Physical Parameters 1073.2 Temperature Profiles in Ice and Snow 1083.3 Bulk Salinity and Salinity Profile 1133.3.1 Bulk Salinity 1153.3.2 Salinity profiles 1163.4 Density of First-Year and Multi-Year Ice 1213.5 Volume Fraction of Sea Ice Constituents 1233.5.1 Brine Volume Fraction 1233.5.2 Solid Salt Volume Fraction 1243.5.3 Pure Ice Volume Fraction 1243.5.4 Air Volume Fraction 1243.5.5 Temperature Dependence of Volume Fractions of Different Components 1253.6 Thermal Properties 1263.6.1 Thermal Conductivity of Sea Ice 1263.6.2 Thermal Conductivity of Snow 1293.6.3 Specific Heat of Sea Ice 1313.6.4 Latent Heat of Sea Ice 1333.7 Dielectric Properties 1343.7.1 Dielectric Constant of Brine 1363.7.2 Dielectric Mixing Models 1363.7.3 Field Measurements of Dielectric Constant 1423.8 References 1464 Laboratory Techniques for Revealing the Structure of Polycrystalline Ice 1494.1 Relevant Optical Properties 1514.1.1 Polarized Light 1514.1.2 Birefringence or Double Refraction of Ordinary (Ih) Ice 1534.1.3 Optical Retardation 1554.1.4 Interference Colors for White Light 1574.2 Ice Thin Sectioning Techniques 1584.2.1 Hot-plate Techniques for Thin Sectioning of Ice 1594.2.2 Double-Microtoming Technique for Thin Sectioning of Ice 1594.2.3 Double-Microtoming Technique for Thin Sectioning of Snow 1614.2.4 Precautions for Thin Sectioning by DMT 1634.2.5 Optimum Thickness for Thin Sections of Ice and Snow 1634.3 Viewing and Photographing Ice Thin Sections 1644.3.1 Laboratory and Hand-Held Polariscope 1654.3.2 Cross-Polarized versus Parallel-Polarized Light Viewing 1684.3.3 Scattered Light and Combined Cross-Polarized/Scattered Light Viewing 1694.3.4 Circularly Polarized Light and Rapid Crystallographic Analysis 1724.4 Advanced Techniques for Revealing Fine Crystallographic Microstructural Features 1734.4.1 Sublimation of Ice and Sublimation Pits 1734.4.2 Etching Processes 1764.4.2.1 Thermal Etching of Microtomed Ice Surfaces 1794.4.2.2 Chemical Etching and Replicating Ice Surfaces 1834.5 References 1885 Polycrystalline Ice Structure 1915.1 Terms and Definitions Relevant to Polycrystalline Ice 1925.1.1 Special Thermal State of Natural Ice 1925.1.2 General Terms for Structural Aspects of Ice 1935.1.3 Basic Terms and Definitions 1945.2 Morphology of Ice 1975.2.1 Forms of Ice Crystals 1975.2.2 Miller Indices for Hexagonal Ice 1985.2.3 Growth Direction of Ice Crystals 1995.2.4 Ice Density in Relation to Crystalline Structure 1995.3 Structure- and Texture-Based Crystalline Classification of Natural Ice 2005.3.1 Freshwater Ice Classification of Michel and Ramseier 2005.3.2 Extending Crystallographic Classification of Freshwater Ice to Sea Ice 2025.3.3 Crystallographic Classes of Natural Ice 2035.3.3.1 Granular or Snow Ice (T1 Ice) 2035.3.3.2 Randomly Oriented (S4) and Vertically Oriented (S5) Frazil Ice 2045.3.3.3 Columnar-Grained with c Axis Vertical (S1) Ice 2055.3.3.4 Columnar-Grained with c Axis Horizontal and Random (S2 Ice) 2075.3.3.5 Columnar-Grained Ice with c Axis Horizontal and Oriented (S3 Ice) 2115.3.3.6 Agglomerate Ice with Discontinuous Columnar-Grained (R Type Ice) 2115.3.3.7 Ice of Land-Based Origin 2125.3.3.8 Platelet Sea Ice 2135.3.4 Stereographical Projection (Fabric Diagram) of Natural Polycrystalline Ice 2145.4 Examples of Crystallographic Structure of Natural Sea Ice 2165.4.1 Crystallographic Structure of Seasonal Sea Ice 2175.4.1.1 Frazil Ice (S5 Type) 2175.4.1.2 Columnar-Grained Ice (S3 Type) 2185.4.1.3 Agglomeration of Various Crystallographic Structures 2205.4.1.4 Air Entrapment in Seasonal Ice 2205.4.2 Crystallographic Structure of Perennial Sea Ice 2215.4.2.1 Hummock Ice 2235.4.2.2 Melt Pond Ice 2265.5 Biomass Accumulation at the Bottom of the Ice 2305.6 Information Contents in Polycrystalline Ice Structure 2325.6.1 Geometric Characteristics of Crystalline Structure 2325.6.2 Geometric Characteristics of Brine Pockets in First-Year Ice 2365.6.3 Geometric Characteristics of Air Bubbles 2425.7 References 2446 Major Field Expeditions to Study Sea Ice 2496.1 The Arctic Ice Dynamic Joint Experiment (AIDJEX) 2506.2 Mould Bay Experiments 1981–1984: Stories that Were Never Told 2526.2.1 Site, Resources, and Logistics 2526.2.2 Sea Ice Conditions 2546.2.3 Aging of Sea Ice: from FYI to MYI 2596.2.4 Interface Between Old and New Ice in Second-Year Ice Profile 2606.3 High Arctic Experience with Ice of Land Origin 2626.3.1 Ward Hunt Ice Shelf and Hobson’s Choice Ice Island Experiment 2626.3.2 Multi-Year Rubble Field Around the Ice Island 2656.4 Labrador Ice Margin Experiment (LIMEX) 2666.5 Sea Ice Monitoring and Modeling Site (SIMMS) Program 2686.6 The Surface Heat Budget of Arctic Ocean (SHEBA) 2706.7 The Norwegian Young Sea Ice Experiment (N-ICE) 2726.8 Marginal Ice Zone (MIZ) Experiments 2746.9 Ice Exercise by Us Navy 2776.10 The Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) 2786.11 References 2807 Remote Sensing Fundamentals Relevant to Sea Ice 2837.1 General Principles of Satellite Remote Sensing 2847.2 Electromagnetic Wave Properties and Processes 2897.2.1 Polarization of EM Wave 2907.2.2 Reflection, Transmission, Absorption, Scattering, and Emission 2927.2.2.1 Reflection and Fresnel Model 2937.2.2.2 Transmission 2957.2.2.3 Absorption and Scattering Losses 2967.2.2.4 Emitted Radiation (Re-radiation) 2967.2.3 Brightness Temperature and Emissivity 2977.2.4 Penetration Depth 2997.3 Optical Sensing 3007.4 Thermal Infrared Sensing 3037.5 Microwave Remote Sensing 3057.6 Imaging Radar Sensing 3087.6.1 Imaging Radar Principles 3087.6.1.1 Radar Equations and Spatial Resolutions of RAR and SAR 3097.6.1.2 Coherency and Polarization of Radar Signals 3117.6.1.3 Radar Scattering Mechanisms 3127.6.2 Multichannel SAR 3137.6.3 SAR Polarimetry: Formulation and Derived Parameters 3157.6.3.1 Formulation of Polarimetric Measurements 3167.6.3.2 Polarimetric Parameters Derived from the FP SAR Data 3177.6.3.3 Linking Radar Scattering Mechanisms to Ice Features 3207.6.3.4 Age-Based versus SAR-Based and Scattering-Based Sea Ice Classification 3217.7 Scatterometer Systems 3227.8 Altimeter Systems 3237.9 Radiative Processes in Relevant Media 3257.9.1 Atmospheric Influences 3257.9.1.1 Influences of Atmosphere on Optical and Infrared Observations 3257.9.1.2 Atmospheric Correction for Passive Microwave Observations 3287.9.2 Seawater 3307.9.2.1 Seawater in the Optical and Thermal Infrared Data 3307.9.2.2 Seawater in the Microwave Data 3317.9.3 Snow on Sea Ice: Physical and Radiative Processes 3337.9.3.1 Snow in Optical and Thermal Infrared Data 3357.9.3.2 Snow in the Microwave Data 3367.10 References 3418 Satellite Sensors for Sea Ice Monitoring 3498.1 Historical Synopsis of Remote Sensing Satellites for Sea Ice 3498.2 Optical and Thermal Infrared Sensors 3528.3 Modern Passive Microwave Sensors 3538.4 Modern Imaging Radar Sensors 3558.5 Scatterometer Sensors 3588.6 Altimeter Sensors 3598.7 References 3609 Radiometric and Scattering Observations from Sea Ice, Water, and Snow 3639.1 Optical Reflectance and Albedo Data 3649.2 Microwave Brightness Temperature Data 3709.3 Radar Backscatter 3769.3.1 Backscatter Databases from Single-Channel SAR 3789.3.2 Dual Polarization Data 3849.3.3 Fully Polarimetric Data 3879.4 Emissivity Data in the Microwave Bands 3959.5 Microwave Penetration Depth 4039.6 References 40710 Retrieval of Sea Ice Surface Information 41110.1 Mechanically Generated Surface Deformation 41210.1.1 Rafted Ice 41210.1.2 Ridged, Rubble, and Brash Ice 41310.1.3 Kinematic Processes: Convergence, Divergence, Shear, and Vorticity 41710.1.4 Cracks and Leads 42110.2 Thermally Induced Surface Features 42810.2.1 Surface Melt 42810.2.1.1 Optical Observations 42810.2.1.2 Passive Microwave Observations 43210.2.1.3 Active Microwave Observations 43410.2.1.4 Airborne Photography 43710.2.2 Frost Flowers 43810.3 Meteorologically Driven Surface Features 44210.3.1 Polynya Identification and Properties 44210.3.2 Snow Depth 44410.4 References 44811 Retrieval of Sea Ice Geophysical Parameters 45311.1 Sea Ice Type Classification 45411.1.1 Ice Classification from Optical and TIR Systems 45611.1.2 Ice Classification from Passive Microwave Data 45711.1.3 Ice Classification from SAR 45811.1.3.1 Ice Classification from Single-Channel SAR 46011.1.3.2 Ice Classification from Dual-Channel SAR 46111.1.3.3 Ice Classification from Polarimetric SAR Data 46711.2 Sea Ice Concentration 47111.2.1 Ice Concentration from Optical and TIR Images 47211.2.2 Ice Concentration from Coarse-Resolution Microwave Observations 47311.2.2.1 NASA TEAM (NT) Algorithm 47511.2.2.2 The Enhanced NASA Team (NT2) Algorithm 47611.2.2.3 The ASI Algorithm 47811.2.2.4 ECICE Algorithm 47911.2.2.5 Intercomparison of PM Algorithms 48611.2.2.6 Sources of Error and Sensitivity of Ice Concentration Algorithms 49011.2.2.7 Assessment of Ice Concentration Results Against Ice Charts 49311.2.3 Ice Concentration from Fine-Resolution SAR 49611.3 Sea Ice Extent and Area 49811.4 Sea Ice Thickness (SIT) 50111.4.1 SIT from TIR Observations 50311.4.2 SIT from PM Observations 50611.4.3 SIT from Altimeter Observations 51011.4.4 SIT from SAR Observations 51411.5 Ice Surface Temperature (IST) 51711.5.1 IST from TIR Observations 51711.5.2 IST from PM Observations 52011.6 Sea Ice Age 52211.7 Sea Ice Motion and Kinematics 52411.7.1 Methods of Ice Motion Tracking 52611.7.1.1 Motion Tracking Using Image Features 52611.7.1.2 Motion Tracking Using Individual Sea Ice Floes 52811.7.2 Operational Ice Motion Products 53211.8 References 53312 Modeling Microwave Emission and Scattering from Snow-Covered Sea Ice 541By Rasmus Tage Tonboe12.1 The Need for Modeling Microwave Emission and Scattering from Snow-Covered Sea Ice 54112.1.1 The ECMWF Workshop and Large-Scale Sea Ice Modeling 54212.1.2 Gross Features of Forward Models 54212.2 Radiative Transfer and Modeling Approaches for Sea Ice Thermal Microwave Emission 54312.2.1 Dense Media Volume Scattering 54312.2.2 Sea Ice Emission Models 54312.2.3 Sea Ice Backscatter Models for Level Ice 54412.2.4 Sea Ice Backscatter Models for Ridged Ice 54512.3 The Input to a Forward Model 54512.3.1 Primary Input Parameters 54512.3.2 Secondary Input Parameters 54612.3.3 Tertiary Input Parameters, Volume, and Surface Scattering 54612.4 Example of the Implementation of an Altimeter Model to Study the Impact of Saline Snow on the Backscatter 54712.5 Example of Combining Atmospheric, Ocean, and Sea Ice Emission Models to Simulate the Noise in Sea Ice Concentration Estimates 54812.5.1 Snow in the Emission Models 54912.5.2 The Combined Sea Ice Thermodynamic, Atmospheric, Ocean, and Sea Ice Emission Models 54912.6 Inverse Modeling 55212.7 References 55313 Impacts of Climate Change on Polar Ice 55713.1 The Inconvenient Truth of Global Warming: How is it Manifested in The Polar Region? 56013.2 Sea Ice Regimes in the Two Polar Regions 56213.2.1 Geographic Differences Between the Two Polar Regions and Their Impacts on Sea Ice 56213.2.2 Differences in Sea Ice Characteristics Between the Two Polar Regions 56413.3 Changes of Polar Sea Ice in Response to Global Warming 56513.3.1 The Arctic and Antarctic Ice Extent 56513.3.2 The Arctic and Antarctic Ice Thickness and Volume 56913.3.3 The Arctic Sea Ice Age 57213.3.4 The Arctic Sea Ice Dynamics 57513.3.5 The Antarctic Icebergs 57613.4 Coupling Between Polar Sea Ice and Environmental Factors 57713.4.1 Interaction of the Arctic Sea Ice with the Environment 57813.4.1.1 Atmospheric Factors that Contribute to Changes in the Arctic Sea Ice 57813.4.1.2 Enhanced Arctic Warming due to Changes of Sea Ice Cover 57813.4.1.3 Arctic Warming due to Sea Ice Advection Out of the Arctic Basin 58013.4.1.4 Interaction of the Arctic Sea Ice with Wind 58213.4.1.5 Mutual Interactions Between the Arctic Sea Ice Cover and Oceanic Forcing 58413.4.2 Interaction of the Antarctic Sea Ice with the Environment 58513.4.2.1 Interaction of the Antarctic Sea ice with Atmospheric Factors 58513.4.2.2 Interaction of the Antarctic Sea Ice with Oceanic Forcing 58613.4.2.3 Interaction Between the Antarctic Sea Ice, Ice Shelves, and Icebergs 58713.5 References 590Index 595