Data Description
A full description of the data processing and uncertainties is given by Dotto et al. (2018) and Naveira Garbato et al. (2019).
1) The regional data (Dotto et al. (2018)) consists of monthly fields of dynamic ocean topography (DOT) and geostrophic currents covering the West Antarctica region, in the area within 85-50S and 145-290E, for the period between February 2011 to February 2016. The measurements were made onboard of CryoSat-2. In sea ice-covered regions of the Southern Ocean, Sea Surface Height (SSH) is estimated from data originating from leads or polynyas and this has been combined with regular open ocean SSH estimates.
SSH estimates are referenced to the geoid EGM2008 (Pavlis et al., 2012). The data are binned in 1˚ longitude x 0.5° latitude grid cells and grid cells are masked if they are within 20km of land to avoid issues with land contamination. The resulting grid is then smoothed with a Gaussian convolution filter, with a radius of 300km. DOT is in units of meters; geostrophic currents are in meters per second. The data is set to NaN over land and in ocean regions that fall within the land mask. The data is stored in netCDF format, DOT_WAnt.nc where:
X -> gridded longitude Y -> gridded latitude TIME -> Gregorian date [year month day hour minute seconds] DOT -> dynamic ocean topography (in m), referenced to EGM2008 geoid. U -> Geostrophic zonal velocity component from DOT (m/s) V -> Geostrophic meridional velocity component from DOT (m/s) SPD -> Speed (in m/s), from sqrt(U^2 + V^2)
2) The pan-Antarctic data (Garbato et al. (2019)) are as follows:
- "SID_SO_binned_daily_1x0p5.mat" - Sea Ice Drift Uice/Vice = zonal/meridional drift m/s X/Y = lon/lat SID_Time = gregorian time
- "SIC_SO_binned_daily_1x0p5.mat" - Sea Ice Concentration seaice = sea ice concentration (between 0 and 1) X/Y = lon/lat SIC_Time = gregorian time
- "ERA_SO_binned_daily_1x0p5.mat" - Wind data Uwind / Vwind = zonal / meridional wind m/s X / Y = lon / lat ERA_Time = gregorian time
- "SO_BinFilt_Gaus300km.mat" - CryoSat-2 dataset binned and filtered Bdot = DOT binned, not filtered in m DOTf3k = DOT filtered in m Uf3k / Vf3k = zonal / meridional geostrophic vel m/s, filtered SPDf3k = SPEED in m/2 i.e, sqrt(Uf3k^2 + Vf3k^2), filtered X / Y = lon / lat
Reference
a) Dotto, T. S., Naveira Garabato, A., Bacon, S., Tsamados, M., Holland, P. R., Hooley, J., et al. (2018). Variability of the Ross Gyre, Southern Ocean: Drivers and responses revealed by satellite altimetry. Geophysical Research Letters, 45, 6195–6204. https://doi.org/10.1029/2018GL078607 b) Naveira Garabato, A. C., Dotto, T. S., Hooley, J., Bacon, S., Tsamados, M., Ridout, A., et al. (2019). Phased response of the subpolar Southern Ocean to changes in circumpolar winds. Geophysical Research Letters, 46, 6024–6033. https://doi.org/10.1029/2019GL082850 c) Pavlis, N. K., Holmes, S. A., Kenyon, S. C., and Factor, J. K. (2012), The development and evaluation of the Earth Gravitational Model 2008 (EGM2008), J. Geophys. Res., 117, B04406, doi:10.1029/2011JB008916.
Data Access
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