Precise models of ocean tides are crucial because (i) the effect of ocean tides has to be removed from CHAMP and GRACE observations in order to obtain gravity field models describing the Earth gravity and (ii) altimetric sea surface heights should be must be reduced for ocean tides in order to be comparable with each other and to be assimilated into numerical models. Deficiencies of ocean tides over continental shelves and in polar oceans are well known – even for the most recent tide models. The present project therefore focuses on two strategies:

1. Empirical improvements to the widely used state-of-the-art ocean tide model FES2004 by (a) determining residuals for major tidal constituents with a spatial resolution as short as 300 km from GRACE data only (long wavelength) and (b) applying response and harmonic analysis to multi-mission altimeter data to estimate in particular for shallow water areas corrections for the dominant tidal constituents and non-linear effects like M4 (short wavelength). Both corrections will be validated and combined to an upgraded FES2004 model subsequently used for a more precise de-aliasing of the GRACE gravity field models and for improved corrections of altimetry data.

2. Hydrodynamic modelling to further enhance the Hamburg Tide Model. Revising expertise these investigations shall provide a quantitative dynamical tide modelling with assimilation in open ocean and shallows sea, capable to overcome the deficiencies of current tide models.

Funding: DFG

Period: 01/2007-02/2013

Project partners: Institut für Theoretische Geodäsie und Satellitengeodäsie (ITSG) / TU Graz and German Research Center of Geosciences (GFZ)

Responsible persons at DGFI: Wolfgang Bosch, Roman Savcenko

 

 

Bosch W., and R. Savcenko. EOT08a - ein neues Gezeitemodell. INTERGEO, Geodätische Woche, Bremen, Germany, 30.09-2.10.2008 (poster)

Bosch, W. (2007), Multi-Mission Altimetry: Joint estimation of relative range biases, radial errors and sea state biases for contemporary missions. ENVISAT Symposium 2007, Montreux, Schweiz, 2007-04-25 (poster)

Mayer-Gürr, T., Savcenko R. Improving ocean tide models by a joint estimation using GRACE and altimetry data, GGEO 2008 Symposium, Chania, Greece, 2008-06

Savcenko, R., W. Bosch (2007), Residual tide analysis in shallow water - contributions of ENVISAT and ERS altimetry. In: H. Lacoste (Ed.) ENVISAT Symposium 2007, ESA SP636, 2007

Savcenko, R., W. Bosch (2007), Empirical ocean tide analysis of cross-calibrated multi-mission altimeter data. IUGG General Assembly. Perugia, Italy, 2007-07-05 (poster)

Savcenko, R., W. Bosch (2007), Assessment of errors in global ocean tide models and their impact on GRACE gravity fields. Joint International GSTM and DFG SPP Symposium, GFZ Potsdam, Potsdam, 2007-10-15 (poster)

Savcenko, R., W.Bosch (2008), EOT08a - empirical ocean tide model from multi-mission satellite altimetry, Report No. 81, Deutsches Geodätisches Forschungsinstitut, München (pdf-file 43MByte!!)

Bosch W., Savcenko R., Flechtner F., Dahle C., Mayer-Gürr T., Stammer D., Taguchi E., Ilk K.-H.: Residual ocean tides signals from satellite altimetry, GRACE gravity fields, and hydrodynamic modelling. Geophys. J. Int. , doi: 10.1111/j.1365-246X.2009.04281.x, 2009

Mayer-Gürr T., Savcenko R., Bosch W., Daras I., Flechtner F., Dahle Ch.: Ocean tides from satellite altimetry and GRACE. J. Geodynamics, early online release. doi: 10.1016/j.jog.2011.10.009, 2011

Richter A., Mendoza L., Perdomo R., Hormaechea J.L., Savcenko R., Bosch W., Dietrich R.: Pressure tide gauge records from the Atlantic shelf off Tierra del Fuego, southernmost South America. Continental Shelf Res., doi:10.1016/j.csr.2012.03.016, 2012