The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 1

Science and Application

Impact Study 2: Geostrophic Current (OCCAM)

< 250 km< 1000 km

OCCAM

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 2

Knowledge of the marine geoid to 1 cm at a scale of 100 km will ensure:

mapping of short-wavelength features (100-200 km) of the dynamic topography to 1-2 cm accuracy on a global basis

identification of practically all features within the mean geostrophic current field by the improved knowledge of the dynamic

topography

better understanding of the role of the positions, strengths and dynamics of the short-spatial scale fronts and jets in controlling

and influencing the ocean circulation

In turn greater confidence in the construction of the next generation ocean and climate models is achieved.

Science and Application

Impact Study 2: Conclusion

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 3

study areas: - several sections in the South Atlantic

input data:- dynamic ocean topography from hydrography

inverse model assimilating hydrographic data and:- altimeter derived mean sea surface, - best available gravity field model (EGM96)

- GOCE simulated geoid error field

Science and Application

Impact Study 3: Ocean Flux Estimates

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 4

Science and Application

Impact Study 3: Ocean Flux Estimates

Mean dynamic topography obtained from inverse model, T/P and EGM96 Sections with transport estimates are marked.

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 5

Science and Application

Impact Study 3: Results

reduction in transport uncertainty when the inverse model is constrained by simulated GOCE geoid height error spectrum instead of best available gravity field model from EGM96

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 6

Knowledge of the marine geoid to 1 cm at a scale of 100 km will ensure:

significant reduction in oceanic transport uncertainties;

- in general most prominent in the upper ocean

- as large as 30%-50% for the South Atlantic

- up to 60% in narrow and intense current paths

- in absolute terms this typically range from 1 to 4 Sv with maxima of the order of 10 Sv (1Sv = 106 m3/s)

Science and Application

Impact Study 3: Conclusion

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 7

Science and Application

Oceanography - Summary

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 8

The GOCE gravity field model with an an accuracy of 1 mgalat a scale of 100 km will:

advance the capabilities to estimate polar ice sheet dynamics and volume changes through combination of bedrock topography derived from space gravity and ice sheet surface topography

Science and Application

Ice Sheets

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 9

The GOCE derived gravity field model and geoid will provide:

• unified global height systems for various sciences & applications

• “levelled” heights from the combination of GPS and the geoid model

• inertial navigation freed of gravity induced errors

• better satellite orbits

Science and Application

Geodesy

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 10

Science and Application

Geodesy - Levelled Heights

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 11

Science and Application

Geodesy - Summary

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 12

Science and Application

Sea Level Change Study: Tidal Records

The Four Candidate Earth Explorer Core Missions Consultative Workshop 12-14 October 1999, Granada, Spain, Revised 2006-01-05 by CCT

GOCE

S 13

Science and Application

Sea Level Change: Conclusion

solid earth sea levelgeodesyiceocean

gravityanomalies

geoidgravityanomalies

geoid

tide gaugesaltimetry

positioning (GPS)

icetopography

oceanaltimetry

post glacialRebound

mean oceancirculation

ice mass balance

orbits

unified height systems

levelled heights

unifiedheight system

bedrocktopography

mean oceancirculation

seismictomograpy

topography

deformations

laboratory

mass balance of ice sheets

constraints on mass

&heat transport

anomalousdensity

structure

gravity anomalies

INS + orbits

+ + ++