Reeve, Krissy A; Boebel, Olaf; Kanzow, Torsten; Strass, Volker H; Gerdes, Rüdiger (2023): Geostrophic Stream function of the Weddell Gyre derived from Argo floats from 2002 to 2016, integrated for the upper 50-2000 dbar [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.960571

All available Argo float data from 2002 to 2016 in the Weddell Sea region were used to fit a stream function of the horizontal circulation of the Weddell Gyre. Argo float trajectories where sequences of positions are available (i.e., under ice profiles have an interpolated position and are therefore excluded) were used to estimate absolute velocity at the parking depth, which is then objectively mapped and fitted with a stream function using a cost function. Within the cost function, boundary conditions are defined such that the flow at the boundary is parallel to the boundary itself. The cost function provides the best fit stream function representative of the entire gyre circulation. The resulting stream function represents horizontal circulation at the parking depth of the Argo floats (usually 800 m; those with a different parking depth were corrected accordingly). Objectively mapped density data from the Argo float profiles were then incorporated to provide geostrophic stream functions for 41 levels between 50 and 2000 dbar. These were then vertically integrated to ultimately provide a geostrophic stream function of the upper 50-2000 dbar of the Weddell Gyre, representative of its mean horizontal circulation. Units are in Sverdrups (Sv), where 1 Sv = 1x10^6 m^3/s, and is the standard unit for quantifying volume transports. Full details of the method for the original stream function data, and the subsequent improvements for the published dataset are available in the supplemental links.

Netcdf file with 3 variables: Latitude, Longitude and StreamFunction.

LongName = 'Geostrophic Stream function (Sv) of the Weddell Gyre derived from Argo Floats for 2002-2016, integrated for 50-2000 dbar'

ShortName = 'Stream Function Weddell Gyre (Sv)'

Date_created = '25-May-2023'

Institute = 'Alfred Wegener Research Institute, Bremerahven, Germany'

Research Group = 'Physical Oceanography of the Polar Seas'

Grid Region boundary coordinates (degrees N,N,E,E) = [-50 -80 40 -70]

Grid_resolution_Lat_degrees_estimate = '~0.5°. Grid is rotated t a 14° angle on the x-axis.'

Grid_resolution_Lon_degrees_estimate = '∼1.7°. Grid is rotated t a 14° angle on the x-axis.'

Grid_resolution_km_estimate = '∼80 × 60 km. Grid is rotated at a 14° angle on the x-axis.'

TimeRange = 'Long-term mean from 2002 to 2016'

Variable StreamFunction:

DATERANGE = 'Long-term mean for 2002-2016'

units = 'Stream function in units of Sverdrups (Sv), where 1 Sv = 1x10^6 m^{-3} '

EVENT = 'Argo float data from 2012 to 2016: Argo float profile and trajectory data and metadata from Global Data Assembly Centre (Argo GDAC). SEANOE. https://doi.org/10.17882/42182, 2000.'

INFILL = 'NaN'

PressureRange = 'Vertically integrated for 50 to 2000 dbar'

Dataresources = 'Refer to https://doi.org/10.1016/j.pocean.2019.04.006 for detailed method. Objectively mapped Argo profile data for 2002-2013 available at https://doi.org/10.5194/essd-8-15-2016'

Comment = 'Grid of stream function in Sv vertically integrated for 50-2000 dbar in the Weddell Gyre, derived from Argo floats (2002-2016). When plotting, to highlight double cell structure (since the western cell is much weaker), contour range 3:5:60 is recommended'