Geostrophic Stream function of the Weddell Gyre derived from Argo floats from 2002 to 2016, integrated for the upper 50-2000 dbar

• Main Authors: Reeve, Krissy A, Boebel, Olaf, Kanzow, Torsten, Strass, Volker H, Gerdes, Rüdiger
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: Argo_float_Weddell_Gyre; Argo floats; Argo profiles; Argo trajectories; Geostrophic; HAFOS; Horizontal circulation; Hybrid Antarctic Float Observation System; ocean circulation; SO-CHIC; Southern Ocean Carbon and Heat Impact on Climate; Stream Function; TRR181; TRR181 Energy transfers in Atmosphere and Ocean; Weddell Gyre; Weddell Sea; Antarctic; Southern Ocean; Weddell; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.960571; 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.