CryoSat: showing the way to a future of improved ocean mapping

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