1 A Climatology of UV Radiation,1979-2000,65S-65N 1
1.1 Introduction 1
1.2 Method 2
1.3 Results 6
1.3.1 Satellite-Derived UV Climatologies 6
1.3.2 Comparison with Ground-Based Measurements 14
1.3.3 Discussion of Uncertanties 16
1.4 Conclusions 17
Acknowledgements 117
References 118
2 Balancing the Risks and Benefits of Ultraviolet Radiation 21
2.1 Introduction 22
2.2 Long Term Changes in UVEry 22
2.3 Geographical Variability in UVEry 23
2.4 Peak UV 24
2.4.1 Peak UV Index 24
2.4.2 Peak UV Daily Dose 28
2.5 Comparing Weighting Functions for Erythema and Vitamin D 29
2.6 Seasonal and Diurnal Variation of UVEry and UVVitD 31
2.7 Global Climatologies of UVEry and UVVitD 33
2.8 Relationship Between UVVitD and UVEry 36
2.9 Production of Vitamin D from Sunlight 38
2.10 Calculation of Optimal Times for Exposure to Sunlight 38
2.11 An Inconsistency 42
2.12 Conclusions 44
Acknowledgements 45
References 45
3 Climatology of Ultraviolet Radiation at High Latitudes Derived from Measurements of the National Science Foundation's Ultraviolet Spec-tral Irradiance Monitoring Network 48
3.1 Introduction 49
3.2 Data Analysis 51
3.2.1 Data 51
3.2.2 Establishment of Climatologies 52
3.2.3 Estimates of Historical UV Indices 52
3.3 UV Index Climatology 56
3.3.1 South Pole 56
3.3.2 McMurdo Station 57
3.3.3 Palmer Station 59
3.3.4 Ushuaia 60
3.3.5 San Diego 60
3.3.6 Barrow 61
3.4 Climatology of UV-A Irradiance 62
3.5 Comparison of Radiation Levels at Network Sites 65
3.6 Conclusions and Outlook 69
Acknowledgements 70
References 70
4 UV Solar Radiation in Polar Regions:Consequences for the Environment and Human Health 73
4.1 Introduction 74
4.2 Networks and Databanks 76
4.3 Impact of Solar UV on the Environment 79
4.3.1 Effect of the Environment on Solar UV 85
4.4 Impact of Solar UV on Human Health 88
4.4.1 Information and Protection Programs 92
4.4.2 Dosimetry,UV Modeling,and Instruments 93
4.5 Concluding Remarks 98
References 99
5 Changes in Ultraviolet and Visible Solar Irradiance 1979 to 2008 106
5.1 Introduction 106
5.2 Instrumentation 112
5.3 Detection of Long-Term Change 121
5.3.1 Radiation Amplification Factor 122
5.3.2 Different Definitions of RAF 125
5.3.3 Estimating UV Trends:Discussion 126
5.3.4 Reduction of UV Irradiance by Clouds and Aerosols 128
5.3.5 Stokes Derivation of CT=(1-R)/(1-RG) 130
5.3.6 UV Absorption 132
5.3.7 Estimating Zonal Average UV Change 132
5.3.8 Estimating UV Trends:Satellites 133
5.3.9 Estimating UV Trends:Ground-Based 138
5.4 UV in the Polar Regions 139
5.5 Human Exposure to UV 140
5.6 UV Index and Units 143
5.7 Action Spectra and Irradiance Trends 143
5.8 UV Summary 151
Appendix 5.1 Calculating RAF(θ) 153
Acknowledgements 155
References 155
6 The Brewer Spectrophotometer 160
6.1 Introduction 160
6.2 History 161
6.3 The Instrument 163
6.3.1 The Fore-Optics 165
6.3.2 The Spectrometer 166
6.3.3 The Photomultiplier Housing 168
6.3.4 Support Electronics 169
6.3.5 The Control Computer 170
6.4 Corrections Applied to Data 170
6.4.1 Dark Count 170
6.4.2 Dead Time 171
6.4.3 Stray Light 172
6.4.4 Temperature Response 172
6.4.5 Neutral Density Filters 173
6.4.6 Cosine Response 173
6.4.7 Internal Polarization 174
6.5 Measurement of Total Ozone 175
6.5.1 Measurement Technique 175
6.5.2 Calibration 177
6.6 Measurement of Spectral UV Radiation 179
6.7 Measurement of Other Atmospheric Variables 181
6.7.1 Vertical Profile of Ozone 182
6.7.2 Atmospheric SO2 182
6.7.3 Atmospheric NO2 183
6.7.4 Aerosol Optical Depth 183
6.7.5 Effective Temperature of Atmospheric Ozone 184
6.8 The Brewer Spectrophotometer as a Powerful Research Tool 185
6.9 Summary 186
Acknowledgements 186
References 186
7 Techniques for Solar Dosimetry in Different Environments 192
7.1 Introduction 192
7.2 UV Dosimetry and Minimization Strategies 194
7.3 Miniaturization of Polysulphone Dosimeters 195
7.4 Measurements on Plants 197
7.5 Long-Term UV Dosimeters 199
7.6 Vitamin D Effective UV Dosimetry 200
7.7 Discussion and Conclusions 201
References 202
8 An Ultraviolet Radiation Monitoring and Research Program for Agriculture 205
8.1 Introduction 206
8.2 Introduction to the USDA UVMRP(Purpose and History) 207
8.3 Monitoring Network 208
8.3.1 Sites and Coverage 208
8.3.2 Data Products Provided by UVMRP 209
8.4 Data Collection and Processing 210
8.4.1 UV-MFRSR Data Processing 212
8.4.2 Erythemally Weighted UV Irradiance 215
8.4.3 Langley Analysis 219
8.4.4 Data Processing for Other Measurements 221
8.5 Derived Products 222
8.5.1 Optical Depth 223
8.5.2 Daily Column Ozone 224
8.5.3 Synthetic Spectrum Data 225
8.6 Database Design and Website Interface 227
8.6.1 The Data 227
8.7 UVMRP's Role in UV-B Agricultural Effects Studies 229
8.7.1 Mississippi State University 230
8.7.2 Purdue University 230
8.7.3 Utah State University 231
8.7.4 University of Maryland 231
8.7.5 Washington State University 231
8.7.6 University of Illinois—Chicago 232
8.7.7 Highlights of Other Collaborations 232
8.8 Modeling of Agricultural Sustainability 233
8.9 Future Considerations 234
8.10 Summary 235
Acknowledgements 237
References 237
9 Radiative Transfer in the Coupled Atmosphere-Snow-Ice-Ocean(CASIO)System:Review of Modeling Capabilities 244
9.1 Introduction 245
9.2 Radiative Transfer Modeling 247
9.2.1 Sun-Earth Geometry 247
9.2.2 Spectrum of Solar Radiation 248
9.2.3 Atmospheric Vertical Structure 249
9.2.4 Light Interaction with Absorbing and Scattering Media 250
9.2.5 Equation of Radiative Transfer 256
9.2.6 Surface Reflection and Transmission 257
9.2.7 Radiative Transfer in a Coupled Atmosphere-Snow-Ice-Ocean(CASIO)System 258
9.3 Sample Applications of the Theory 259
9.3.1 Comparison of Modeled Irradiances in CAO Systems 259
9.3.2 Measured and Modeled Radiation Fields in Sea Ice 261
9.3.3 Radiation Trapping in Sea Ice 261
9.3.4 Impact of Ozone Depletion on Primary Productivity 263
9.4 Discussion and Conclusions 264
Acknowledgements 265
References 265
10 Comparative Analysis of UV-B Exposure Between Nimbus 7/TOMS Satellite Estimates and Ground-Based Measurements 270
10.1 Introduction 271
10.2 Materials and Methods 274
10.2.1 USDA UV-B Dataset 274
10.2.2 TOMS Dataset 274
10.2.3 UV Index 276
10.2.4 Comparative Analysis 276
10.3 Results and Discussion 277
10.3.1 UV-I Daily Change Analysis 277
10.3.2 Analysis of UV-I Variability 279
10.3.3 UV-I Spatial Analysis 281
10.4 Conclusions 287
Acknowledgements 289
References 289
11 Ultraviolet Radiation and Its Interaction with Air Pollution 291
11.1 Introduction 291
11.1.1 Factors Affecting UV Flux at the Earth's Surface 292
11.2 Optics of the Atmosphere 301
11.2.1 Scattering 301
11.2.2 Absorption 303
11.2.3 Emission 304
11.2.4 Atmospheric Optical Depth 304
11.2.5 Single Scatter Albedo 309
11.2.6 Asymmetry Factor 310
11.2.7 Angstrom's Exponent 310
11.3 Models and Measurements 310
11.4 Summary 325
Reterences 326
12 Urban Forest Influences on Exposure to UV Radiation and Potential Consequences for Human Health 331
12.1 Introduction 332
12.2 Effects of Solar UV on Human Health and Epidemiology 333
12.2.1 Sunburn 333
12.2.2 Skin Types 336
12.2.3 Immune Function 336
12.2.4 Skin Cancers 336
12.2.5 Eye Diseases 339
12.2.6 Sunscreen Effectiveness 339
12.2.7 Positive Impacts 339
12.3 UV Climatology 344
12.3.1 Ozone Trends 344
12.4 Urban Structural Influences 346
12.4.1 Sky Radiance and Diffuse Fraction 346
12.4.2 UV Reflectivity 347
12.4.3 Tree and Building Influences on UV 347
12.4.4 Human Exposure 356
12.5 Public Health Information 357
12.6 Conclusions 358
Acknowledgements 359
References 360
13 Solar UV-B Radiation and Global Dimming:Effects on Plant Growth and UV-Shielding 370
13.1 Introduction 371
13.1.1 Global Dimming and UV-B:Potential Effects on Plants 371
13.1.2 Assessing Global Dimming and UV-B Effects on Plant Growth 372
13.2 Methods 374
13.2.1 Field Site 374
13.2.2 Structural and Biomass Measurements 375
13.2.3 UV-A Epidermal Transmittance Measurements 376
13.2.4 Solar UV and PAR Irradiance 376
13.2.5 Statistical Analyses 377
13.3 Results 377
13.3.1 UV-A Epidermal Transmittance 377
13.3.2 Dimming Effects on Biomass and Structure 381
13.4 Discussion 383
13.4.1 Global Dimming and UV-B Effects on Leaf Optical Properties 384
13.4.2 Global Dimming and UV-B Effects on Productivity 384
13.4.3 Ecological Implications 385
13.5 Concluding Remarks 388
Acknowledgements 389
Reterences 389
14 Effects of Ultraviolet-B Radiation and Its Interactions with Climate Change Factors on Agricultural Crop Growth and Yield 395
14.1 Introduction 396
14.2 Abiotic Stress Factors and Crop Yield 400
14.3 Crop Responses to UV-B and Other Climate Change Factors 401
14.3.1 Specific Effects ofUV-B Radiation on Plants 402
14.3.2 Strategies for Protection against UV-B Radiation 410
14.3.3 Crop Response to Atmospheric CO2Concentration 412
14.3.4 Crop Response to Temperature 413
14.3.5 Crop Response to Drought 414
14.3.6 Crop Response to Multiple Abiotic Stress Factors 416
14.4 Abiotic Stress Tolerance and Cultivar Screening Tools 419
14.5 Climate Change and Aerobiology and Public Health 422
14.6 Concluding Remarks 423
Acknowledgements 424
References 424
15 Assessment of DNA Damage as a Tool to Measure UV-B Tolerance inSoybean Lines Differing in Foliar Flavonoid Composition 437
15.1 Introduction 438
15.2 Materials and Methods 441
15.2.1 Plant Growth and UV Irradiation 441
15.2.2 Field Sampling 442
15.2.3 Analysis of Phenolics 443
15.2.4 Determination of DNA Lesions—Gel Electrophoresis Method 443
15.2.5 Determination of DNA Lesions—Monoclonal Antibody Method 446
15.2.6 Experimental Design and Statistical Analysis 446
15.3 Results and Discussion 446
15.3.1 Leaf Phenolics 446
15.3.2 DNA Damage 448
15.4 Conclusions 452
Acknowledgements 453
References 453
16 Physiological Impacts of Short-Term UV Irradiance Exposures on Cultivars of Glycine Max 458
16.1 Introduction 459
16.2 Materials and Methods 461
16.2.1 Plant Material and Greenhouse Growth Conditions 461
16.2.2 UV Treatment 462
16.2.3 UV Exposure Regimes 463
16.2.4 Stomatal Conductance Measurements 466
16.2.5 Photosynthesis and Transpiration Measurements 467
16.2.6 Pigment Analyses 467
16.2.7 UV-B Absorbing Compounds 468
16.3 Results and Discussion 469
16.3.1 Stomatal Conductance 469
16.3.2 Transpiration 473
16.3.3 Photosynthesis 476
16.3.4 Water Use Efficiency 478
16.3.5 UV-B Absorbing Compounds and Leaf Pigments 478
16.4 Summary and Conclusions 481
Acknowledgements 483
References 483
17 UV-Effects on Young Seedlings of Soybean:Effects in Early Development and Long-Term Effects 488
17.1 Introduction 488
Main Objectives 492
17.2 Results and Discussion 492
17.2.1 UV Effects on Early Development and Survival of Young Soybean 492
17.2.2 Surviving Soybean:the Affect on Seed Production 496
17.2.3 Assessment of Phenylpropanoids in Response to UV 498
17.3 Conclusions 499
17.4 Methods 500
17.4.1 Plant Materials and Accessions 500
17.4.2 Plant Growth and Preparation of Tissue 500
17.4.3 Chemicals 501
17.4.4 UV Radiation Sources and Treatments 501
17.4.5 Metabolome Studies 501
Acknowledgements 502
References 502
18 Characteristics of UV-B Radiation Tolerance in Broadleaf Trees in Southern USA 509
18.1 Introduction 510
18.2 Methodology 514
18.2.1 Plant Materials 514
18.2.2 Measuring Leaf Optical Properties 514
18.2.3 Measuring the Light Penetration and Distribution within Leaf Tissues 515
18.2.4 Scanning Electron Microscopy and Light Microscopy of Leaves 517
18.2.5 Measurements of UV-B Absorbing Compounds and Chlorophyll Concentrations 517
18.2.6 Statistical Analysis 518
18.3 Results and Discussion 518
18.3.1 Leaf Optical Properties 518
18.3.2 Depth of Light Penetration into Leaf Tissues 519
18.3.3 The Concentration of Leaf UV-B Absorbing Compounds 522
18.3.4 Correlations among the UV-B Related Variables within and among the Species 524
18.4 Conclusions 527
Acknowledgements 527
References 528
Index 531