On the Transition from Profile Altimeter to Swath Altimeter for Observing Global Ocean Surface Topography

Journal of Atmospheric and Oceanic Technology - Tập 31 Số 2 - Trang 560-568 - 2014
Lee‐Lueng Fu1, Clément Ubelmann1
1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California

Tóm tắt

Abstract Conventional radar altimeter makes measurement of sea surface height (SSH) in one-dimensional profiles along the ground tracks of a satellite. Such profiles are combined via various mapping techniques to construct two-dimensional SSH maps, providing a valuable data record over the past two decades for studying the global ocean circulation and sea level change. However, the spatial resolution of the SSH is limited by both coarse sampling across the satellite tracks and the instrument error in the profile measurements. A new satellite mission based on radar interferometry offers the capability of making high-resolution wide-swath measurement of SSH. This mission is called Surface Water and Ocean Topography (SWOT), which will demonstrate the application of swath altimeter to both oceanography and land hydrology. This paper presents a brief introduction to the design of SWOT, its performance specification for SSH, and the anticipated spatial resolution and coverage, demonstrating the promise of SWOT for fundamental advancement in observing SSH. A main objective of the paper is to address issues in the anticipated transition of conventional profile altimetry to swath altimetry in the future—in particular, the need for consistency of the new observing system with the old for extending the existing data record into the future. A viable approach is to carry a profile altimeter in the SWOT payload to provide calibration and validation of the new measurement against the old at large scales. This is the baseline design of SWOT. The unique advantages of the approach are discussed in the context of a new standard for observing the global SSH in the future.

Từ khóa


Tài liệu tham khảo

Capet, 2008, Surface kinetic energy transfer in surface quasi-geostrophic flows, J. Fluid Mech., 604, 165, 10.1017/S0022112008001110

Ducet, 2000, Global high-resolution mapping of ocean circulation from the combination of TOPEX/Poseidon and ERS-1 and -2, Geophys. Res., 105, 19 477, 10.1029/2000JC900063

Durand, 2010, The Surface Water and Ocean Topography mission: Observing terrestrial surface water and oceanic submesoscale eddies, Proc. IEEE, 98, 766, 10.1109/JPROC.2010.2043031

Dussurget, 2011, Fine resolution altimetry data for a regional application in the Bay of Biscay, 34, 447

Escudier, 2013, Improvement of coastal and mesoscale observation from space: Application to the northwestern Mediterranean Sea, Geophys. Res. Lett., 40, 2148, 10.1002/grl.50324

Fu, 2001, Satellite Altimetry and Earth Sciences: A Handbook of Techniques and Applications

Fu, 2004

Fu, 2008, Observing oceanic submesoscale processes from space, Eos, Trans. Amer. Geophys. Union, 89, 488, 10.1029/2008EO480003

Fu, 2013, The challenges in long-term altimetry calibration for addressing the problem of global sea level change, Adv. Space Res., 51, 1284, 10.1016/j.asr.2012.06.005

Fu, 2010, Eddy dynamics from satellite altimetry, Oceanography, 23, 14, 10.5670/oceanog.2010.02

Fu, 2012

Hamlington, 2012, Improving sea level reconstructions using non-sea level measurements, J. Geophys. Res., 117, C10025, 10.1029/2012JC008277

Lapeyre, 2006, Impact of the small-scale elongated filaments on the oceanic vertical pump, J. Mar. Res., 64, 835, 10.1357/002224006779698369

Pujol, 2012, Using high-resolution altimetry to observe mesoscale signals, J. Atmos. Oceanic Technol., 29, 1409, 10.1175/JTECH-D-12-00032.1

Richman, 2012, Inferring dynamics from the wavenumber spectra of an eddying global ocean model with embedded tides, J. Geophys. Res., 117, C12012, 10.1029/2012JC008364

Shchepetkin, 2005, The regional ocean modeling system (ROMS): A split-explicit, free-surface, topography-following-coordinate oceanic model, Ocean Modell., 9, 347, 10.1016/j.ocemod.2004.08.002

Vincent, 2003, Jason-1 geophysical performance evaluation, Mar. Geod., 26, 167, 10.1080/714044517

Willis, 2010, Global sea level rise: Recent progress and challenges for the decade to come, Oceanography, 23, 26, 10.5670/oceanog.2010.03

Wunsch, 2013

Xu, 2012, The effects of altimeter instrument noise on the estimation of the wavenumber spectrum of sea surface height, J. Phys. Oceanogr., 42, 2229, 10.1175/JPO-D-12-0106.1