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Displacements for GRGS sites

We provide 3-D (North, East & Up) displacements in millimeters for GRGS (GNSS and DORIS) sites (Figure 1) due to:

• atmospheric loading estimated from surface pressure from ECMWF operational model (3 hours), assuming an inverted barometer ocean response to pressure forcing (.atmib extension),
• atmospheric loading estimated from surface pressure from ECMWF operational model (3 hours), assuming a dynamic ocean response to pressure & winds from TUGO-m barotropic model (Carrere & Lyard, 2003) (3 hour & 0.25 degree) (.atmmo extension),
• atmospheric loading estimated from surface pressure from ERA interim (ECMWF Reanalysis) model (6 hours), assuming an inverted barometer ocean response to pressure forcing (.erain extension),
• hydrology loading (soil-moisture and snow) estimated from ERA interim (ECMWF Reanalysis) model (6 hours) (.erahyd extension),
• hydrology loading (soil moisture, snow and canopy water), estimated from GLDAS/Noah v1.0 (Rodell et al., 2004) (3 hours, 0.25 degree) model (.gldas extension). Permanent ice-covered regions (Greenland, Alaska, mountain glaciers, etc.) have been masked out.
• hydrology loading (soil moisture and snow), estimated from MERRA-land (Reichle et al., 2011) (1 hour, 0.50x0.67 degree) model (.merra extension). Permanent ice-covered regions have been masked out.
• hydrology loading (soil moisture and snow), estimated from MERRA2 (Gelaro et al., 2017) (1 hour, 0.50x0.625 degree) model (.merra2 extension). Permanent ice-covered regions have been masked out.
• hydrology loading, estimated from NASA GSFC iterated global mascons (Luthcke et al., 2013; Loomis & Luthcke, 2016) (monthly and 1 degree) (.grace extension). GIA effects are removed using GeruoA model (A et al., 2013).

• non-tidal ocean loading estimated from ECCO1 (kf080i) (Wunch et al., 2009) ocean bottom pressure (12 hours, about 1 degree) (.ecco extension),
• non-tidal ocean loading estimated from ECCO2 (Menemenlis et al., 2008) ocean bottom pressure (daily, 0.25 degree) (.ecco2 extension).
• non-tidal ocean loading estimated from GLORYS2v3 (Ferry et al., 2012) ocean bottom pressure (daily, 0.25 degree) (.glorys extension).

Loading estimates (in millimeters) are provided in the Center-of-Mass (CM) & Center-of-Figure (CF) reference frames.

We use different land/sea mask models depending on the loading computations; for ECMWF products (operational or reanalysis), we use one with a 0.10-degree resolution, for the others (ECCO, GLORYS, GLDAS & MERRA), we use a 0.25-degree mask. Both of them are derived from the GMT (Generic Mapping Tools) database.

Figure 1: Location of the GRGS sites; the names & coordinates can be found here

Careful: As TUGO-m model is forced not only by atmospheric pressure but also by surface winds, loading estimates from classical ocean general circulation model (such as ECCO) should not be added to the (ECMWF+TUGO-m) loading computations.