Horizontal circulation and volume transports in the Weddell Gyre derived from Argo float data

Reeve, Krissy; Boebel, Olaf; Strass, Volker; Kanzow, Torsten; Gerdes, Rüdiger

doi:10.1016/j.pocean.2019.04.006

Cited by 34 publications

(48 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another strong internal branch, which transports about 25 Sv roughly following the 4,000 m isobath and not extending beyond 71 • S, is associated with the WDW gyre recirculation that is not directly involved in water mass modifications induced by intense cooling and sea ice formation on the Weddell Sea continental shelves. These simulated circulations are consistent with the overall observational picture (e.g., Armitage et al, 2018;Schröder & Fahrbach, 1999;Reeve et al, 2019). In particular, the total flow in the southern branch of the gyre entering the domain from the east is, if somewhat stronger, roughly consistent with the estimates at 0 • E by Schröder & Fahrbach (1999, 66 Sv) and Klatt et al (2005, Thompson and Heywood (2008), totaling to 46 ± 8 Sv (with the remainder of the gyre transport occurring further east).…”

Section: 1029/2019jc015847supporting

confidence: 87%

The Role of Tides in Ocean‐Ice Shelf Interactions in the Southwestern Weddell Sea

et al. 2020

View full text Add to dashboard Cite

To investigate the role of tides in Weddell Sea ocean‐ice shelf melt interactions, and resulting consequences for ocean properties and sea ice interactions, we develop a regional ocean‐sea ice model configuration, with time‐varying ocean boundary and atmospheric forcing, including the deep open ocean (at 2.5–4 km horizontal resolution), the southwestern continental shelf (≈2.5 km), and the adjacent cavities of eastern Weddell, Larsen, and Filchner‐Ronne ice shelves (FRIS, 1.5–2.5 km). Simulated circulation, water mass, and ice shelf melt properties compare overall well with available open ocean and cavity observational knowledge. Tides are shown to enhance the kinetic energy of the time‐varying flow in contact with the ice shelves, thereby increasing melt. This dynamically driven impact of tides on net melting is to almost 90% compensated by cooling through the meltwater that is produced but not quickly exported from regions of melting in the Weddell Sea cold‐cavity regime. The resulting systematic tide‐driven enhancement of both produced meltwater and its refreezing on ascending branches of, especially the FRIS, cavity circulation acts to increase net ice shelf melting (by 50% in respect to the state without tides, ≈50 Gt yr−1). In addition, tides also increase the melt‐induced FRIS cavity circulation, and the meltwater export by the FRIS outflow. Simulations suggest attendant changes on the open‐ocean southwestern continental shelf, characterized by overall freshening and small year‐round sea ice thickening, as well as in the deep southwestern Weddell Sea in the form of a marked freshening of newly formed bottom waters.

show abstract

Section: 1029/2019jc015847supporting

confidence: 87%

The Role of Tides in Ocean‐Ice Shelf Interactions in the Southwestern Weddell Sea

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Another strong internal branch, which transports about 25 Sv roughly following the 4000 m isobath and not extending beyond 71 • S, is associated with the WDW gyre recirculation that is not directly involved in water-mass modifications induced by intense cooling and sea-ice formation on the Weddell Sea continental shelves. These simulated circulations are consistent with the overall observational picture (e.g Schröder and Fahrbach, 1999;Armitage et al, 2018;Reeve et al, 2019)…”

supporting

confidence: 87%

The role of tides in ocean--ice-shelf interactions in the southwestern Weddell Sea

Hausmann¹,

Sallée²,

Jourdain

et al. 2020

Preprint

View full text Add to dashboard Cite

<p>A novel regional ocean-sea-ice model configuration is designed to investigate the mechanisms of ocean&#8211;ice-shelf-melt interactions in the Weddell Sea. It features explicit resolution of the cavities of eastern Weddell, Larsen and Filchner-Ronne ice-shelves (FRIS, at 1.5-2.5 km horizontal resolution), as well as of the adjacent continental shelves (~2.5 km) and deep open-ocean gyre (at 2.5-4 km), in presence of interannually-varying atmospheric and ocean boundary forcing as well as explicit ocean tides. Simulated circulation, water mass and ice-shelf melt properties compare overall well with available open-ocean and cavity observations, and simulated Weddell ice-shelf melting reveals large variability on tidal, seasonal and year-to-year timescales.&#160;The presence of ocean tides, investigated explicitly, is revealed to result in a systematic time-average enhancement of both the production of ice-shelf meltwater as well as its refreezing on ascending branches of especially the FRIS cavity circulation. This tide-driven enhancement of the melt-induced FRIS cavity circulation acts to increase net ice-shelf melting (by 50%, ~50 Gt/yr) and the meltwater export by the FRIS outflow, and modulates their seasonal and lower frequency variability.&#160;The tidal impact on ice-shelf melting is consistent with being primarily driven mechanically through enhanced kinetic energy of the time-varying flow in contact with the ice drafts. The dynamically-driven tide-induced melting is thereby to almost 90% compensated by cooling through meltwater produced, but not quickly exported from regions of melting in the Weddell cold-cavity regime. Ocean boundary layer thermal adjustment underneath ice drafts, minimizing departures from the in-situ freezing point, thus substantially dampens the impact of tides on Weddell ocean&#8211;ice-shelf interactions.&#160;Simulations furthermore suggest attendant changes on the open-ocean continental shelves, characterized by overall freshening and modest year-round sea-ice thickening, as well as a marked freshening of newly-formed bottom waters in the southwestern Weddell Sea.</p>

show abstract

“…Here, we investigate the coupling between physical and biological processes in the Maud Rise region using data from four SOCCOM floats deployed in late 2014 and early 2015. Floats 5904468 and 5904471 (the “Maud Rise floats,” “MR1” and “MR2,” respectively) circulated closely around Maud Rise for 4 years, while floats 5904467 and 5904397 (the “Gyre floats,” “WG1,” and “WG2,” respectively) remained in the eastern cell of the Weddell Gyre (Orsi et al, 1993; Reeve et al, 2019), north of the seamount (see trajectories in Figure 1b). Interannual variability in bloom phenology is analyzed using chlorophyll a (chl‐ a ) profiles derived from fluorescence.…”

Section: Methodsmentioning

confidence: 99%

Weddell Sea Phytoplankton Blooms Modulated by Sea Ice Variability and Polynya Formation

Berg

Prend

Campbell

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

Seasonal sea ice retreat is known to stimulate Southern Ocean phytoplankton blooms, but depth‐resolved observations of their evolution are scarce. Autonomous float measurements collected from 2015–2019 in the eastern Weddell Sea show that spring bloom initiation is closely linked to sea ice retreat timing. The appearance and persistence of a rare open‐ocean polynya over the Maud Rise seamount in 2017 led to an early bloom and high annual net community production. Widespread early ice retreat north of Maud Rise in 2017, however, had a similar effect, suggesting that the polynya most impacted the timing of bloom initiation. Still, higher productivity rates at Maud Rise relative to the surrounding region are observed in all years, likely supported by flow‐topography interactions. The longer growing season in 2017–2018 also allowed for separation of distinct spring and fall bloom signals, the latter of which was primarily subsurface and associated with mixed‐layer deepening.

show abstract

Horizontal circulation and volume transports in the Weddell Gyre derived from Argo float data

Cited by 34 publications

References 52 publications

The Role of Tides in Ocean‐Ice Shelf Interactions in the Southwestern Weddell Sea

The Role of Tides in Ocean‐Ice Shelf Interactions in the Southwestern Weddell Sea

The role of tides in ocean--ice-shelf interactions in the southwestern Weddell Sea

Weddell Sea Phytoplankton Blooms Modulated by Sea Ice Variability and Polynya Formation

Contact Info

Product

Resources

About