Post on 01-Jan-2016
CryoSat Workshop, March 9, 2005 1Walter.HF.Smith@noaa.gov
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 2Walter.HF.Smith@noaa.gov
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 3Walter.HF.Smith@noaa.gov
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 4Walter.HF.Smith@noaa.gov
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 5Walter.HF.Smith@noaa.gov
QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
CryoSat Workshop, March 9, 2005 6Walter.HF.Smith@noaa.gov
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 7Walter.HF.Smith@noaa.gov
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 8Walter.HF.Smith@noaa.gov
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