Discovering the Ocean from Space

Series: Springer Praxis Books Subseries: Geophysical Sciences Jointly published with Praxis Publishing, UK 1st Edition., 2010, XLVI, 638 p. 165 illus., 135 in color. The remote sensing of oceans from space has developed rapidly since 1978 when the first dedicated ocean viewing sensors were launched. In 1991 the first European Space Agency remote sensing satellite carried sensors primarily for the ocean, heralding the widespread use of satellite date by oceanographes. In the mid 1990's the US/French TOPEX-Poseidon mission revolutionised the performance of satellite altimetry and since 1997 NASA's SeaWiFs mission has delivered operational measurements of ocean colour. The new millennium has seen the launch of several very large remote sensing platforms ans a number of smaller missions by ESA, NASA and NASDA, providing almost comprehensive worldwide measurements of sea surface waves and wind, temperature, colour, currents and other ocean properties. The increasing availability of so much satellite data has undoubtedly changed the way the science of oceanography has developed. The unique perspective provided by satellites has revealed previously undetected ocean phenomena, cast new light on old problems and opened the way for new fields of oceanographic study. Content Level » Research Keywords » Remote sensing - SST - Satellite Oceanography - Topography Related subjects » Environmental Toxicology - Geophysics & Geodesy - Hydrogeology - Oceanography

Contents Preface..................................................xv Abbreviations ......................................... xix List of figures ........................................ xxi List of tables ......................................... xxxi List of abbreviations and names of satellites and sensors ............. xxxiii List of symbols and nomenclature ............................ xli 1 Introduction ....................................... 1 1.1 An important observational tool for planetary science ....... 1 1.2 Putting remote sensing to work for oceanographers ........ 3 1.3 The oceanographic scope of the book ................. 4 1.4 Reference..................................... 6 2 The methods of satellite oceanography ...................... 7 2.1 Ocean remote-sensing techniques—a summary ............ 7 2.2 The unique sampling capabilities of sensors on satellites ..... 9 2.2.1 Creating image-like data fields from point samples .... 9 2.2.2 Satellite orbits and how they constrain remote sensing . 11 2.2.3 The space-time sampling capabilities of satellite sensors . 14 2.3 Generic data-processing tasks ....................... 16 2.3.1 Sensor calibration .......................... 17 2.3.2 Atmospheric correction ...................... 19 2.3.3 Positional registration ....................... 21 2.3.4 Geophysical product derivation ................ 21 2.3.5 Image resampling onto map projections ........... 23 2.3.6 Composite image maps ...................... 26 Preface .............................................2.4 Sensor types for observing the ocean .................. 28 2.4.1 Using the electromagnetic spectrum .............. 28 2.4.2 Ocean color radiometers ..................... 30 2.4.3 Thermal infrared radiometry for measuring sea surface temperature .............................. 35 2.4.4 Microwave radiometry ...................... 42 2.4.5 Altimetry for measuring surface slope, currents, and wave height ................................. 46 2.4.6 Oblique-viewing radars for measuring sea surface rough- ness................................... 51 2.5 Platforms and sensors for satellite oceanography ........... 54 2.6 Satellite ocean data products ....................... 54 2.7 References .................................... 66 3 Mesoscale ocean features:Eddies ......................... 69 3.1 Discovering mesoscale variability from space ............. 69 3.2 Mesoscale ocean eddies ........................... 72 3.2.1 Eddies—ubiquitous phenomena in a turbulent ocean . . . 72 3.2.2 Lengthscales of mesoscale eddies—the Rossby radius . . 72 3.2.3 The dynamical structure of rings and eddies ........ 76 3.3 Detecting eddies from satellites....................... 78 3.4 Using SSHA from altimetry to observe eddies ............ 80 3.4.1 Revealing ocean eddies in altimeter SSHA data ...... 80 3.4.2 Present limitations of satellite altimetry ............ 86 3.4.3 Kinematic measurements from altimetric SSHA fields . . 88 3.4.4 The distribution of mesoscale turbulent energy ...... 89 3.5 Observation of eddies and mesoscale turbulence in the SST field 91 3.5.1 SST signatures of eddies in infrared imagery ........ 91 3.5.2 Microwave radiometry for viewing ocean eddies ..... 96 3.6 Views of mesoscale turbulence from ocean color ........... 98 3.7 Surface roughness signatures of eddies .................. 103 3.7.1 Hydrodynamic modulation patterns of eddies ........ 103 3.7.2 Slick-modulated signatures of eddies .............. 106 3.7.3 Sun glitter photography ...................... 109 3.7.4 Can imaging radar become a reliable tool for observing turbulent eddies? ........................... 110 3.8 References .................................... 111 4 Mesoscale ocean features:Fronts.......................... 115 4.1 Boundaries in the ocean .......................... 115 4.2 The remote-sensing signatures of ocean fronts ............ 118 4.2.1 Sea surface temperature signatures of fronts ........ 118 4.2.2 Can fronts be detected by altimetry? ............. 124 4.2.3 Observing fronts in ocean color images ........... 126 vi Contents4.2.4 Frontal signatures in radar surface roughness images . . 129 4.2.5 Direct measurement of currents using Doppler analysis of SARdata ............................... 134 4.3 Tracking fronts ................................ 136 4.3.1 Mapping frontal edges ...................... 136 4.3.2 Automatic parameterization of frontal structure ...... 140 4.4 Climatology of the major ocean fronts ................. 142 4.5 Mesoscale frontal variability ........................ 146 4.5.1 The Gulf Stream .......................... 146 4.5.2 The Southland Front ........................ 148 4.5.3 Antarctic Circumpolar Fronts .................. 148 4.6 Biological production associated with ocean fronts ......... 152 4.6.1 Antarctic Circumpolar Current ................. 152 4.6.2 Fronts in the southwest Atlantic ................ 153 4.7 References .................................... 155 5 Ocean mesoscale features:Upwelling and other phenomena ......... 159 5.1 Upwelling .................................... 159 5.1.1 The causes and consequences of upwelling ......... 159 5.1.2 Aspects of upwelling detected by satellites ......... 162 5.1.3 Upwelling regions of the world seen from space ..... 167 5.1.4 Using satellite data in upwelling research........... 171 5.2 Wind-driven, offshore, dynamical features ............... 174 5.3 Large river plumes .............................. 177 5.4 Island wakes .................................. 179 5.5 Ice edge phytoplankton blooms ...................... 181 5.6 Remote sensing in iron limitation studies ............... 184 5.7 Making the most of satellite data for mesoscale studies: conclu- sions from Chapters 3–5 .......................... 187 5.8 References .................................... 190 6 Planetary waves and large-scale ocean dynamics ................ 195 6.1 Phenomena seen best from satellites ................... 195 6.2 Detecting planetary waves from space ................. 196 6.2.1 Producing composite anomaly datasets ............ 197 6.2.2 Producing Hovmoller diagrams to reveal propagating features ................................ 200 6.2.3 Altimetry reveals the first compelling evidence of planet- ary waves ............................... 202 6.2.4 Sea surface temperature signatures ............... 204 6.2.5 Evidence of planetary waves in ocean color ........ 206 6.3 The characteristics of Rossby waves ................... 206 6.3.1 A summary of planetary wave theory ............ 206 6.3.2 How can Rossby waves be seen at the sea surface? . . . 210 Contents vii6.4 Estimating planetary wave speed ..................... 212 6.4.1 Methods for analyzing Hovmoller diagrams ......... 212 6.4.2 Radon transform .......................... 213 6.4.3 Mapping the speed of planetary waves ............ 216 6.4.4 Meridional components of planetary wave propagation . 216 6.5 Understanding Rossby waves better ................... 220 6.5.1 Satellite data confirm the existence of Rossby waves . . . 220 6.5.2 Revisiting Rossby wave theory . . . .............. 221 6.5.3 The importance of Rossby waves . .............. 223 6.6 Other large-scale propagating phenomena . .............. 224 6.6.1 Equatorial Kelvin waves ..................... 225 6.6.2 Tropical instability waves .................... 227 6.6.3 The Madden–Julian Oscillation . . . .............. 231 6.6.4 The Antarctic circumpolar wave . . .............. 233 6.7 References .................................... 234 7 Ocean biology from space .............................. 239 7.1 Introduction ................................... 239 7.2 Phytoplankton blooms ........................... 240 7.2.1 An unfolding new view of phytoplankton distribution . . 240 7.2.2 The global distribution of chlorophyll ............. 246 7.2.3 Scientific exploitation of satellite ocean color data .... 251 7.2.4 Coccolithophores .......................... 254 7.3 Primary production ............................. 255 7.3.1 Theoretical background ...................... 255 7.3.2 Methods for estimating production from remote sensing 258 7.3.3 Estimating PARfrom space ................... 262 7.3.4 Measurements of primary production ............. 264 7.4 Fisheries ..................................... 267 7.4.1 General considerations ...................... 267 7.4.2 Fisheries management and research .............. 268 7.4.3 Operational applications to specific fisheries ........ 270 7.4.4 Aquaculture ............................. 271 7.5 Habitats in shallow tropical seas ..................... 272 7.6 Coral reefs—a wider role for satellite data .............. 279 7.7 Marine biology in the future ....................... 282 7.8 References .................................... 283 8 Ocean surface waves ................................. 293 8.1 Introduction ................................... 293 8.2 Measuring ocean waves—principles .................... 294 8.2.1 Characterizing ocean waves in terms of measurable parameters............................... 294 8.2.2 Wave energy and spectra ..................... 295 8.2.3 Significant wave height ...................... 296 viii Contents8.2.4 Measuring ocean waves from an altimeter ......... 298 8.2.5 Observing waves with the synthetic aperture radar (SAR) 300 8.2.6 Wave spectrometry ......................... 304 8.3 Measuring ocean waves—practical systems .............. 307 8.3.1 Altimeters for measuring SWH ................. 307 8.3.2 SWH data products from altimeters ............. 309 8.3.3 Synthetic aperture radars ..................... 312 8.3.4 ASARwave-related products .................. 313 8.4 Applications of wave data from satellites ............... 317 8.4.1 Applications of SWH ....................... 317 8.4.2 Applications of SAR ....................... 318 8.5 Using satellite data in wave prediction models ............ 319 8.5.1 Wave prediction models ..................... 319 8.5.2 Use of satellite data with wave models ............ 320 8.5.3 Assimilating satellite data into models ............ 321 8.6 Wave climate .................................. 322 8.7 Assessment and future perspectives ................... 326 8.8 References .................................... 328 9 Wind over the sea ................................... 333 9.1 Measuring wind over the sea from satellites .............. 333 9.1.1 Scatterometry . . . .......................... 334 9.1.2 Wind data from SAR ....................... 336 9.1.3 Wind data from altimeters .................... 336 9.1.4 Microwave radiometry ....................... 337 9.1.5 The alternatives to satellite measurements .......... 340 9.2 Oceanography and wind data ....................... 341 9.2.1 Differences between analysis winds and satellite winds . . 342 9.2.2 Which type of wind data should be used to study ocean phenomena? . . . .......................... 342 9.3 Tropical cyclones over the ocean ..................... 344 9.3.1 Detecting and predicting tropical cyclones ......... 344 9.3.2 Use of ocean remote sensing to study hurricane–ocean interaction ............................... 347 9.4 Satellite winds for offshore wind farms ................. 350 9.5 References .................................... 354 10 Fluxes through the air–sea interface ........................ 359 10.1 Introduction ................................... 359 10.2 Determining fluxes .............................. 361 10.2.1 General principles ......................... 361 10.2.2 Theoretical basis of flux parameterizations .......... 362 10.3 Satellite data available for surface fluxes ................ 363 10.3.1 Sea surface temperature ..................... 364 10.3.2 Wind .................................. 365 Contents ix10.3.3 Sea surface roughness ....................... 366 10.3.4 Significant wave height and wave age ............. 367 10.3.5 Water vapor ............................. 368 10.3.6 Air temperature at sea level ................... 369 10.3.7 Gas concentrations in the surface sea and the ABL . . . 369 10.4 Measuring fluxes from space ........................ 370 10.4.1 Radiative flux ............................ 370 10.4.2 Gas flux ................................ 372 10.4.3 Turbulent heat flux ........................ 378 10.5 Satellite flux measurements in future? .................. 382 10.6 References .................................... 386 11 Large ocean phenomena with human impact................... 391 11.1 Introduction ................................... 391 11.2 El Nino ..................................... 393 11.2.1 The ENSO phenomenon...................... 393 11.2.2 Observing an El Nino from satellites ............. 402 11.2.3 Observing an El Nino in sea surface temperature from satellites ................................ 404 11.2.4 Applying altimetry to the study of El Nino......... 407 11.2.5 Satellite-observed wind fields and ocean surface currents . 410 11.2.6 Chlorophyll .............................. 415 11.2.7 Rainfall over the ocean ...................... 418 11.2.8 Synergy ................................ 419 11.3 Monsoons .................................... 421 11.3.1 Introduction ............................. 421 11.3.2 Illustrating the Indian monsoon using satellite data .... 422 11.3.3 Interannual variability of the Indian monsoon ....... 424 11.4 Sea ice distribution .............................. 426 11.4.1 Introduction ............................. 426 11.4.2 Measuring sea ice from space .................. 427 11.4.3 How is the distribution of sea ice changing? ........ 431 11.5 Tides, sea level, surges, and tsunamis .................. 435 11.5.1 A surveyor’s benchmark in the sky .............. 435 11.5.2 Mean sea level ............................ 437 11.5.3 Storm surges ............................. 441 11.5.4 Tsunamis ............................... 442 11.6 Conclusion ................................... 444 11.7 References .................................... 447 12 Internal waves...................................... 453 12.1 Introduction ................................... 453 12.1.1 Ocean internal and interfacial waves ............. 453 12.1.2 The importance of internal waves in physical and bio- logical oceanography ....................... 456 x Contents12.2 Internal wave signatures detected with SAR ............. 457 12.2.1 Introduction.............................. 457 12.2.2 Internal, solitary wave packets observed by SAR ..... 459 12.2.3 Identification of internal wave trains and their propaga- tion direction . . . .......................... 462 12.2.4 Hydrodynamic and film modulation .............. 463 12.2.5 Internal wave mean propagation speed ............ 468 12.2.6 Inversion of polarity in SARsignatures of internal waves 468 12.3 Internal waves and ocean color ...................... 471 12.3.1 Observations . . . .......................... 471 12.3.2 Remote sensing and depth distribution of ocean chlorophyll .............................. 474 12.3.3 A model for interpreting ocean color signatures of internal tides . . . .......................... 475 12.3.4 Internal waves and primary production ............ 477 12.4 Impact of remote sensing on our knowledge of internal waves . . 479 12.5 References .................................... 480 13 Shelf seas, estuaries, and coasts .......................... 485 13.1 Introduction ................................... 485 13.2 Observing shelf seas from space ..................... 486 13.2.1 What is distinct about the remote sensing of shelf seas? 486 13.2.2 Variability scales in shelf seas .................. 488 13.2.3 Shelf edge phenomena ....................... 492 13.2.4 Thermal signatures of shelf sea dynamical phenomena . . 497 13.2.5 Remote sensing of suspended sediments in shelf seas . . 508 13.2.6 Monitoring ecosystems and water quality .......... 516 13.3 Coastal altimetry ............................... 523 13.3.1 Challenges and opportunities for altimetry in coastal seas 523 13.3.2 Potential applications of coastal and shelf altimetry . . . 524 13.3.3 Practical approaches to improving altimeter accuracy in shelf seas ............................... 527 13.4 Coastal and estuarine remote sensing .................. 528 13.4.1 Important edges of the ocean .................. 528 13.4.2 A mismatch of scales? ...................... 529 13.4.3 Coastal remote-sensing applications using satellite data. . 532 13.5 References .................................... 534 14 Putting ocean remote sensing to work ...................... 539 14.1 Satellites and applied oceanography ................... 539 14.1.1 Introduction . . . .......................... 539 14.1.2 The fundamental importance of ocean monitoring and forecasting .............................. 540 14.1.3 Motivation for scientists to engage in applied ocean remote sensing . .......................... 541 Contents xi14.2 Integrated ocean-forecasting systems ................... 543 14.2.1 What is operational oceanography? .............. 543 14.2.2 Combining satellite oceanography and ocean models for operational tasks........................... 547 14.2.3 Assimilating satellite data into ocean-dynamical models . 551 14.3 Ecosystem modeling ............................. 555 14.3.1 How can satellite ocean color data support operational applications? ............................. 555 14.3.2 Marine ecosystem models, scientific principles, and operational purpose ........................ 555 14.3.3 Ways in which ocean color data are used in ocean modeling ............................... 558 14.3.4 Sequential assimilation to constrain ecosystem state variables ............................... 562 14.3.5 Characterizing light penetration in numerical models . . 564 14.3.6 Alternative approaches to ocean color assimilation .... 565 14.4 Preparing satellite data for operational use .............. 569 14.4.1 Providing merged data from multiple sensors/satellites . 570 14.4.2 GHRSST: A case study on preparing SST data for operational applications ..................... 575 14.5 Oil spill monitoring ............................. 583 14.5.1 Introduction ............................. 583 14.5.2 How can oil spills be monitored routinely from space? . 584 14.5.3 CleanSeaNet, a European service for oil spill detection . 586 14.6 Using satellite data for climate monitoring .............. 588 14.6.1 Introduction ............................. 588 14.6.2 The ocean’s role in the climate system ............ 589 14.6.3 Essential climate variables .................... 591 14.6.4 Ocean datasets used for climate . . . .............. 597 14.7 References .................................... 602 15 Looking forward .................................... 607 15.1 Achievements ................................. 607 15.1.1 Oceanographic discoveries from satellite data ....... 607 15.1.2 Does ocean science need remote sensing? .......... 609 15.2 Securing the future for ocean remote sensing ............. 610 15.2.1 Essential satellite oceanography . . .............. 610 15.2.2 Limitations of existing sensors and platforms ....... 611 15.2.3 Future sensors, platforms, and systems for observing the ocean ................................. 613 15.3 Challenges for satellite oceanographers . . . .............. 617 15.4 References .................................... 619 Index .............................................. 621

Professor Ian S. Robinson School of Ocean & Earth Science University of Southampton National Oceanography Centre European Way Southampton UK

暂无其它内容！

暂时还没有人为这本书评论！