cryosat: showing the way to a future of improved ocean mapping
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CryoSat: showing the way to a future of improved ocean mapping. Walter H. F. Smith NOAA Lab for Satellite Altimetry Silver Spring, Maryland. Ocean altimetry of VD, G, and B. Sea surface slope reveals Vertical Deflection of Gravity, and may be correlated with Bathymetry. - PowerPoint PPT PresentationTRANSCRIPT
CryoSat Workshop, March 9, 2005 [email protected]
CryoSat:showing the way to a futureof improved ocean mapping
Walter H. F. Smith
NOAA Lab for Satellite Altimetry
Silver Spring, Maryland
CryoSat Workshop, March 9, 2005 [email protected]
Ocean altimetry of VD, G, and B
Sea surface slope reveals Vertical Deflection of Gravity, and may be correlated with Bathymetry.
CryoSat offers first space-test of improved resolution of VD, G & B, with many applications.
CryoSat Workshop, March 9, 2005 [email protected]
Resolve Control on Ocean Mixing Rate
Spatial variations in bottom roughness change mixing rates by order of magnitude (vertical diffusivity < 105
at left and > 104 at right; actual in situ data shown).
10–30 km bathymetry controls mixingHigher-resolution altimetry can map the controlling scales.
SlowerMixing
Smoother bottom
FasterMixing
Rougher bottom
CryoSat Workshop, March 9, 2005 [email protected]
Increase seamount detection 17xProbably 50,000 seamounts 1 km tall remain undetected.
2x better seamount resolution will find 17x more seamounts.
CryoSat Workshop, March 9, 2005 [email protected]
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CryoSat Workshop, March 9, 2005 [email protected]
CryoSat: showing the way ahead
CryoSat is the first non-repeat-track (“geodetic orbit”) altimeter since ERS-1 (1994) and Geosat (1985).
• Sandwell et al. will use CryoSat conventional altimeter mode data over global ocean to improve marine gravity field.
CryoSat SAR mode offers first space demonstration of delay-Doppler altimetry.
• Raney et al. will demonstrate improved H and reduced sensitivity to SWH over ocean surface.
• Smith et al. will demonstrate improved resolution of VD, G & B over oceans.
CryoSat Workshop, March 9, 2005 [email protected]
Ocean mapping beyond CryoSat
An ocean mapping mission needs:
• “Geodetic” (non-repeat) orbit
• SAR-mode over all ocean
• Moderate inclination
CryoSat’s polar orbit resolves only N-S component of VD.
North slope
East slope
CryoSat Workshop, March 9, 2005 [email protected]
Envisat measured the Indian Ocean tsunami
ESA’s Envisat altimeter measured a sea level anomaly on 26 Dec 2004 associated with the tsunami.
These data are being used at NOAA to improve a model for the tsunami source mechanism and wave field.
Altimeters are the only source of deep-water data on this tsunami.
A NOAA press release credits ESA for this valuable asset and contribution.
See http://www.noaanews.noaa.gov/stories2005/s2365.htm