Massentransporte und Massenverteilungen im System Erde  
 
 SPP1257 / Projekte / STREMP 
  STREMPSTREMP  
 

 

Spatial and Temporal Resolution Limits for Regional Mass Transport and Mass Distribution (STREMP)

STREMP-Team

Technische Universität Darmstadt:Luciana Fenoglio-Marc (fenoglio@ipg.tu-darmstadt.de) Matthias. Becker  
GeoForschungsZentrum Potsdam/
Universität Bonn:
Roelof Rietbroek, Jürgen Kusche
Universität Oldenburg/
GKSS Geesthacht
Sebastian Grayek, E. Stanev
Universität Heidelberg:Lucas Menzel, Tim Aus der Beek

Summary

The main goal of STREMP is the regional estimation of mass transport and mass distribution in the Mediterranean and Black Sea and their catchments.

 

During the first two phases a generally good agreement between the two estimates of mass change and between the straits flow estimated from the closure of the budget and from sparse measurements was found. Main topics in the third phase are the interaction and coupling of dedicated regional hydrology and ocean models.

 

General goals are:

 

1) Determination, analysis and separation of the different components of the mass storage, such as ocean transport,exchange between land and ocean in Southern Europe and the exchange between the Black Sea, the Mediterranean sea and the Atlantic Ocean.

 

2) Improved representation of ocean processes as a result of increasing synergy between newly available satellite data and oceanic and hydrologic modeling

 

3) Full exploitation of altimetry and GRACE data to attain their resolution limits in space and time.

 

4) Exploitation of the upcoming GOCE geoid and estimation of the mean dynamic topography

Figure 1: Region of study: Mediterramean-Black Sea and their catchments

Results of Phase I (Goals 1-3, Partners 1-3)

In Phase I two composite time-series, the hydrology corrected GRACE derived time-variable mass change and the steric-corrected sea level change from altimeter observations, are regionally compared at seasonal and interannual scales over the interval 2002-2007. The leakage of mass change from land in the GRACE estimates of ocean mass change is accounted for by removing hydrologic models (Fenoglio et al., 2006, 2007). The leakage of the remaining land signal is largest in the smallest basin considered, the Black Sea.

 

Results of Phase II (Goals 1-4, Partners 1-4)

Main contributions of the on-going Phase II are:

  • Improved estimates of coastal sea level
  • Interannual scale water mass re-distribution from GRACE (Figure 2)
  • Improved performance of the Black Sea NEMO prediction of oceanic currents by assimilation of altimetric data into the model by applying a Kalman filter approach (Figure 3)
  • Regional WaterGAP hydrology model version for the Mediterranean and Black Sea regions (Figure 4).
  • Confidence levels for observed and modeled contributions
Figure 2. Basin average of de-seasonalized seawater mass anomalies from filtered steric-corrected altimetry (circle) and from hydrology-corrected GRACE (triangle). The GIA correction has been applied
Figure 3. EOF-2 (left) and PC-2 (right) from analysis of SLA-EMC from AVISO altimetry (black line), dot product of EOF-2 and free model steric heights (red line) and alternatively the product with steric heights from assimilation run using data from AVISO (green line) and data from Task 1 (blue line)
Fig.4. Comparison of WaterGAP3 with semi-climatological reconstructed total river runoff (left) and with global WaterGAP model (right).

Anticipated contribution to SPP in Phase III (Goals 1-4, Partners 1-4)

In Phase III the assimilation of data in models will play a very important role in constraining and improving models. On land, GRACE will provide data input to hydrology modelling in regions where traditional data are missing. On sea GRACE data will be used for constraining time-variable mass transport. The effects of de-aliasing on the GRACE fields and the leakage effects in small basins are studied. Furthermore, GOCE data will be used to better quantify the mean circulation in the Black Sea.

  • Identification of effects of filtering and post-processing /de-aliasing of GRACE data
  • Consistency between mass change estimates from GRACE and from steric-corrected altimetry on sea and hydrology on land
  • Separation of the GRACE signal in components corresponding to different time- and spatial-scales
  • Separation of GRACE signal in components corresponding to the ocean and land compartments
  • Separation of Total Water Storage Change (TWSC) signal into hydrological compartments linking GRACE to hydrological processes within WaterGAP3
  • Improved mean dynamic topography
  • Improved long-term sea level change estimatel
  • Improved shelf circulation, turbulent eddy kinetic energy and diapycnal mixing estimates in the shelf regions
  • Improved ocean mass transport, water budget and relationship between fresh water fluxes, strait exchange and sea level change
  • Improved Total Water Storage Changes (TWSC)
  • Improved separation in components of WaterGAP3 by assimilation of GRACE and data from selected compartments

Direct collaboration within SPP-1257

  • IMPLY: improved modeling of non-tidal mass variations for optimized gravity fied analysis
  • REGHYDRO: Combined hydrological modelling and regional geodetic estimation of water storage variations in large river basins using GRACE data
  • TASMAGOG: Temporal And Spatial Multiscale Assessment of mass transport by combination of Gravity Observations from GRACE and terrestrial stations
  • JIGOG: Surface mass redistribution from joint inversion of GPS site displacements, ocean bottom pressure (OBP) models, and GRACE global gravity models
  • DAROTA: Dynamic and Residual Ocean Tide Analysis for Improved GRACE de-aliasing

List of Publications

1) Fenoglio-Marc L., J. Kusche and M. Becker (2006). Mass variation in the M Fenoglio-Marc, L., J. Kusche, and M. Becker (2006), Mass variation in the Mediterranean Sea from GRACE and its validation by altimetry, steric and hydrologic fields, Geophys. Res. Lett., 33, L19606, doi:10.1029/2006GL026851

 

2) Fenoglio-Marc L., J. Kusche, M. Becker and I. Fukumori (2007). Comments on “On the steric and mass-induced contributions to the annual sea level variations in he Mediterranean Sea” by D. Garcia et al., J. of Geoph. Res., Vol. 112, C12018,doi:10.1029/2007JC004196

 

3) Fenoglio-Marc L., J. Kusche, M. Becker (2007). Estimation of mass variation and mean dynamic topography in the Mediterranean Sea from altimetry and GRACE/GOCE geoids, in 3rd GOCE Users Symposium Proceedings, SP-627, ESA Publications Division

 

4) Kusche, J (2007): Approximate decorrelation and non-isotropic smoothing of time-variable GRACE-type gravity fields, Journal of Geodesy, 81:733-749.

 

5)Kusche J, Schmidt R, Petrovic S, Rietbroek R (2009): Decorrelated GRACE time-variable gravity solutions for science by GFZ, and their validation using a hydrological model, Journal of Geodesy, (accepted Feb 2009)

 

More information from: www.ipg.tu-darmstadt.de/en/p_fenoglio