Anatomy of Subinertial Waves Along The

Anatomy of subinertial waves along the Patagonian shelf break in a 1/12° global operational model Léa Poli, Camila Artana, Christine Provost, Jérôme Sirven, Nathalie Sennéchael, Yannis Cuypers, Jean-Michel Lellouche

To cite this version:

Léa Poli, Camila Artana, Christine Provost, Jérôme Sirven, Nathalie Sennéchael, et al.. Anatomy of subinertial waves along the Patagonian shelf break in a 1/12° global operational model. Journal of Geophysical Research. Oceans, Wiley-Blackwell, 2020, 125 (12), pp.e2020JC016549. 10.1029/2020jc016549. hal-03015284

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Anatomy of subinertial waves along the Patagonian shelf break in a 1/12° global

operational model

Léa Poli 1, Camila Artana 2, Christine Provost 1, Jérôme Sirven 1, Nathalie Sennéchael 1,

Yannis Cuypers 1, Jean-Michel Lellouche 2

1) LOCEAN-IPSL, Sorbonne Université (UPMC, Univ. Paris 6)-CNRS-IRD- MNHN, Paris, France

2) MERCATOR OCEAN, Parc Technologique du Canal, Ramonville St. Agne,

France

Key points Article 1- Velocity signals with phase speeds of 140-300 cm/s at the shelf break and 10-30

cm/s in the core of the Malvinas Current were identified.

2- At the shelf break, wind-forced fast waves modulated the inner Malvinas Current jet

and possibly contributed to upwelling

3- Slowly propagating waves in the core of the Malvinas Current came from the

Malvinas Escarpment or the Drake Passage.

Key words:

topographic waves, shelf break, Malvinas Current, jets, upwelling, global operational model, Current-meter data.

Accepted

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1029/2020JC016549.

This article is protected by copyright. All rights reserved. Escarpme Malvinas the and Passage Drake backthe to between 450 and 1200 km and were not forced by the M the of core the in waves propagating Slow events. spatial and temporal structures and scales consiste t 0 from varied which jet, inshore the of intensity to abrupt changes in the shelf break orientation. T velocity variations and triggered fast propagating 47° of south variations stress wind zonal large The 6 20-day, atto cm/s 3010 cm/s) speeds from (phase slow and days, 110 and 5 between periods at cm/s) break shelf the along all signals propagating fast of locations specific at signals phase in signals: ove Statistics days. 10 than larger periods at (MC) reanalysis to examine waves at the shelf break and u We waves. of variety a hosts slope Patagonian The :Abstract This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article the shelf break to the south of 47°S, 47°S, of south the to break shelf the waves at distinct sites corresponding o 30 cm/s at 100 m depth, and had had and depth, m 100 at cm/s 30 o he shelf break waves modulated the (phase speed from 140 cm/s to 300 300 to cm/s 140 from speed (phase nt with those of observed upwelling r 25 years indicated three types of of types three indicated years 25 r in the core of the Malvinas Current 0-day and 100-day periods. periods. 100-day 0-day and C had along-slope wavelengths wavelengths along-slope had C er signals in the core of the MC the of core the in signals er S forced in-phase along-slope along-slope in-phase forced S local local winds. They were tracked nt. nt. sed a state of the art ocean ocean art the of state a sed Cur theof Malvinas velocities the modified Passage Malvinas the from propagating waves Slow upwelling. M the of jet coastal the of intensity the modulated observations. Strong westerly winds forced fast wav wav of the of state variety a in waves the examined We documented. a hosts slope Patagonian sinuous The summary: Plainlanguage This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

alvinas Current and the shelf break shelf the and Current alvinas es es at the shelf break. These waves rent main jet. jet. main rent art ocean model assimilating assimilating model ocean art Escarpment and the Drake Drake the and Escarpment es that are yet poorly poorly yet are that es Confluence showed large energy peaks between 5 and and 5 between peaks energy large showed Confluence the across 41°S at deployed moorings meters current V slope. Patagonian the along northward propagating e possible the at pointed have observations situ In 2016). al., activ mesoscale the of part large a filters Plateau is among the greatest in the world ocean with value with ocean world the in greatest the among is ki eddy surface The Confluence. Brazil-Malvinas the (Figure 1b; Artana et al., 2018a). At 38°S the MC e SA main the follows jet main the while (SAF-N), SAF corresp jet onshore the of location mean The 2013). alienated structure two-jet stable relatively a by 1b) and the MC is organized in one narrow jet. Sou 60 north observedare cm/s) of where43°S botto the mea The 40 largest of meancm/s. withazonal value M the and orientated east-west are isobaths 48°S At wide (300 km) with mean northward surface velocitie ov m (2000 gentle and orientated west-east is slope world, is strongly controlled by bottom topography. the of one borders which MC, The America. South of al (SAF) Front Subantarctic the following northward Circumpolar Antarctic the of offshoot an is Ocean, boundary western major a (MC), Current Malvinas The 1. 1c). In contrast, the EKE in the MC is rather small rather is MC the in EKE the contrast, In 1c). This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

Introduction with two bottom terraces (Piola et al., et (Piola terraces bottom two with ncounters ncounters the Brazil Current forming Between 52°S and 49°S the bottom ity from Drake Passage (Artana et et (Artana Passage Drake from ity th th of 43°S, the MC is characterized ong the eastern continental slope slope continental eastern the ong (200 cm(200 s exceeding 2000 cm2000 exceeding s xistence of trapped waves (TW) (TW) waves trapped of xistence s s of 30 cm/s (Figures 1a and 1b). netic energy (EKE) at this region region this at (EKE) energy netic m m slope is 1asteep (Figures and onds to a northern branch of the of branch northern a to onds er 300 km) and the MC is rather rather is MC the and km) 300 er n surface velocities in the MC (> n insurface the velocities slope near the Brazil Malvinas Malvinas Brazil the near slope Current (Figure 1a) that flows flows that 1a) (Figure Current C mean surface velocities are are velocities surface mean C widest continental shelf of the of shelf continental widest elocity spectra obtained from from obtained spectra elocity current of the South Atlantic Atlantic South the of current F along the 1500 m isobath isobath m 1500 the along F 110 days (Vivier and Provost Provost and (Vivier days 110 2 /s 2 ) since the Malvinas Malvinas the since ) 2 /s 2 (Figure (Figure 2019) sea of maps altimetry-derived satellite in resolved of TW along the Patagonian slope. As the propaga TW observati these Despite 2001). al., et Vivier 1999; ocnrtos ekn a 2530 mg/m 2.5-3.0 b at shelf peaking continental concentrations Patagonian the of portion inner observed et the(Romero over shelf Patagonian al., development of the biological activity in this regi wat Subantarctic nutrient-rich cold, carries MC The waves detected at the shelf break and interpret the interpret and break shelf the at detected waves waves in observations and the Mercator Ocean reanal compar first We follows. as organized is paper This guidance. provided stratification, and topography velocities group and phase structure, spatial whose i which (1982), Brink from theory The days. 10 than the in and break shelf the at TWs examine to fields us we o comparison, this of result velocities a As observations. and anomalies level sea reanalysis the furthe we Here 2019). al., et Artana and 2018a al., reanaly this of performance the assessed have works provide insights some on propagating TW along the P track satellite altimetry, such as the Mercator Oce assimilat that (1/12°) models ocean resolution High nutrieof the enhance fluxes could and thermocline This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article . .

3 (Figure 1d). TW disturbs the upper upper the disturbs TW 1d). (Figure on: on: massive phytoplankton blooms are an physical reanalysis at 1/12°, could ons there is still no characterization characterization no still is there ons level anomalies (Ballarotta et al., al., et (Ballarotta anomalies level nts to the shelf break. to shelf ntsthe m using the idealized model from from model idealized the using m r evaluate the spectral content of of content spectral the evaluate r 2006; Valla Piola,and2015). The core of the MC at periods larger larger periods at MC the of core along- and observations situ in e dealizes TW as a sum of modes of sum a as TW dealizes e possible signatures of trapped trapped of signatures possible e e the reanalysis tri-dimensional tri-dimensional reanalysis the e ysis. ysis. In section 3, we explorefast ers that play a key role in the the in role key a play that ers depend upon the cross-shore cross-shore the upon depend atagonian break.shelf Previous sis in the MC system (Artana et et (Artana MCsystem the in sis tes they rapidly are not entirely n the slope compared to to compared slope the n reak presents chlorophyll chlorophyll presents reak The high resolution (1/12 resolution high The 2. concludes. 5 Section 4. section in examined are isobath m 1500 Brink and Chapman (1987). Slower velocity variation the continental slope between the model and observa and model between the slope the continental over MC the and witha good agreement found observa performa the evaluated (2018a) al. et Artana 2016). (Ca databases situ in CORA latest the from profiles t situ in and Concentration, Sea-Ice Ifremer/CERSAT Sur Sea satellite AVHRR 2016), al., et (Pujol CMEMS tra along jointly assimilates model The 2018). al., a 7-day a and error background the of decomposition wi filter Kalman order reduced a using observations Forecasts. Weather Medium-Range for Center European a ERA-Interim global the by forced is surface ocean co dynamical the is platform) Ocean the of Modeling N errors. observation and data assimilated forcing, forecasting CMEMS system (Lellouche et al., 2018) w o based is reanalysis This (1993-2017). years 25 of Copernic the Monitoring (CMEMS, http://marine.copernicus Service of framework the in developed been has This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

2.1 Model and data: possible signatures of trapped wav trapped of signatures possibledata: Model and

Mercator Ocean reanalysis reanalysis Mercator Ocean ° ) global Mercator Ocean reanalysis (hereafter GLORY (hereafter reanalysis Ocean Mercator global ) banes et al., 2013; Szekely et al., et Szekely 2013; al., et banes nce of the reanalysis GLORYS12 GLORYS12 reanalysis the of nce s s in the core of the MC above the ck satellite altimetric data from from data altimetric satellite ck ith a few changes in atmospheric emperature and salinity vertical vertical salinity and emperature tions are shown below. below. shown are tions tmospheric reanalysis from the from reanalysis tmospheric .eu/) and extends over a period .eu/) extendsand aoverperiod face Temperature from NOAA, NOAA, from Temperature face n the current real time global global time real current the n re of the physical model. The The model. physical the of re ssimilation cycle (Lellouche et et (Lellouche cycle ssimilation EMO (Nucleus of European European of (Nucleus EMO tions. Further comparisons on on comparisons tions. Further th a 3-D multivariate modal modal multivariate 3-D a th es es discusses the results and and results the discusses The model assimilates assimilates model The us Marine Environment Environment Marine us S12) S12) m isobaths. m Those periods could be associated with waves propag exhibit days 100 and 60-70 20, as such periods Some variability outstanding the reflects 40°S of north energ of continuum The spectra. the dominates cycle s display spectra significant energy peaks at distinct periods betwee The 2b). (Figure GLORYS12 and 2a) slope. Their spectra are shown as a function of lat 1 and 300 the between anomaly level sea averaged of altimetry satellite et 2018a, al.,(Artana their fi the on values EKE larger somewhat produces GLORYS12 2020 al., et Archer in (e.g., space km 200and time sp in interpolation measurements from different altimeters and its effe optimal an from results ht product at available 2018) al., et Taburet 2016; al., et We used DUACS delayed time altimeter gridded (1/4° across the continental slope at 41°S near the Confl the near 41°S at slope continental the across Current meter moorings have been deployed in 1993-1

days. days. varia capture not do data gridded satellite Indeed, 2c).(Figure 14days and5 tha between energy more displayed GLORYS12 expected as and This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article 2.2 2.3

GLORYS12 and satellite altimetry spectral contents contents spectral altimetry satellite andGLORYS12 GLORYS12 and mooring data on the slope at 41°S 41°S atslope thedataon mooringand GLORYS12

There was no energy at periods shorter than 5 days 5 than shorter periods at energy no was There gures 1b and 1d). We gures 1b 1d). andbuilt a time series We itude itude for the DUACS product (Figure n 10 days and 500 days. The annual at the Brazil-Malvinas confluence. confluence. Brazil-Malvinas the at ). ). ctive resolution is about 20 days in uence (Vivier and Provost, 1999; 1999; Provost, and (Vivier uence tions at periods smaller than 14 14 than smaller periods at tions tp://marine.copernicus.eu/. This This tp://marine.copernicus.eu/. y observed in the spectra to the the to spectra the in observed y ating ating between the 300 and 1700 regular regular grid) daily product (Pujol 995, 995, 2001-2003 and 2014-2015 ed energy all along the slope. slope. the along all energy ed 700 m isobaths all along the the along all isobaths m 700 ace and time, combining combining time, and ace along the slope slope alongthe Patagonian slope than than slope Patagonian rkn smlrte with similarities triking n altimetry at periods periods at altimetry n in either spectrum, spectrum, either in slope (lagged correlations with Lagged correlations are shown as a function of dist of function a as shown are correlations Lagged orltos with Correlations (60.5°W,53.5°S) correl were 4a) Figure in points (colored isobath m Th cycle. seasonal the remove to applied was filter slope Patagonian the of isobath m 300 the following velocity along-slope of propagation the examined We inGLORYS12. isobaths m 1500 and 300 differen of Evidence years: 25 over Statistics 2.4 complexr and energetic highly this in observations i were GLORYS12 from ellipses variance the and flow i The 2019). al., et Artana 2018; al., et (Paniagua sout exceptionally being position Confluence the to ellip variance large particular in with deployments the and patterns general the reproduced accurately GL green, in 2014-2015 blue, in 2001-2003 black, in the slope, and weaker mean flow and more round elli th in stretched ellipsesand East North the towards consi showed ellipses variance and means other, the pass filtered for Incomparison. spite of significa days, A 5 than shorter periods 2017).at energy significant al., et Ferrari 2009; Provost, and Spadone and applied a linear fit (dashed lines in Figure 4) Figure in lines (dashed fit linear a applied and pr lagthe selected we isobath the along point each This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article , , Ω Φ

(60.5°W,47°S) ee aiu a lg t te ot o k 20 r > (r 200 km of south the to 0 lag at maximum were Φ in Figure 4b, and , Ψ (56.8°W,41°S) Ω nt differences from one deployment to in Figure 4c and ses during the last deployment due due deployment last the during ses to estimate propagation velocities propagation estimate to ntensity and direction of the mean mean the of direction and ntensity e direction of the mean flow above above flow meanthe of direction e t propagation velocities above the the above velocities propagation t egion (Figure 3). 3). (Figure egion the mooring data were 5-day low- 5-day were data mooring the esenting the maximum correlation correlation maximum the esenting e filtered velocities along the 300 300 the along velocities filtered e (Figure 4). A 110-day high-pass high-pass 110-day A 4). (Figure ated with those at locations locations at those with ated pses offshore (Figure 3, 1993-95 rmMyt etme 2015 September to May from h ance from from ance stent patterns with a mean flow mean a with patterns stent ORYS12 in red). GLORYS12 GLORYS12 red). in ORYS12 differences between mooring mooring between differences (black points in Figure 4a). 4a). Figure in points (black anomalies at 100 m depth depth m 100 at anomalies n good agreement with the the with agreement good n s GLORYS12 showed no no showed GLORYS12 s Φ Ψ (53.5°S) along the the along (53.5°S) in Figure 4d). For 0.5) and and 0.5) Φ ( . oe f h M, hwd oe oaie faue arou features localized more showed MC, the of core velocities along-slope between correlations Lagged 0.25. of withsmall correlations associated t superposed 0.5) exceeding correlations with 40°S, between propagation localized more and cm/s) 30 and with was reminiscent of the one observed at 41°S over thover 41°S at observed one theof was reminiscent (Figure 2100 and 1600 km between days 50 of period the core of the MC with propagation velocities rang velocities thewith propagation MC of the core sh the along all cm/s 300 to 140 from ranging speed f break, shelf the at 47°S of south the to phase in Statistics over years25 of GLORYS12 revealed three Lagged correlations with correlations Lagged speed phase similar at signals propagating same the maximum correlations at lag 0 nearby lag at 0correlations maximum of about 50 days extending from km 800 to km 1600 ( km to800 km from extending days about50 of indicated propagating signals (with r > 0.3) with a features were consistently found in the lagged corr lagged the in found consistently were features signals diminished with distance and remained signi associat correlations The cm/s. 300 and 140 between propagation and a period about 40 days (Figure 5b). (Figure days 40 about period a and propagation 4b) 4b) suggested northward propagations from in dots pink <0.5, r simultaneous signals. In addition, two high-correla (0.3< 1050 and 600 km between (59.2°W, 47°S)and (59.2°W, This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Ψ ’ suggested propagating signals with a phase speed phase a with signals propagating suggested ’ Ψ ’ (56°W, 41°S) ’ (56°W, Ψ (Figure 4d) showed a slower (phase speed between between speed (phase slower a showed 4d) (Figure (Figure 5). Correlations at Correlations 5). (Figure Ω and Φ Φ and from (r > 0.5), and two patterns suggesting suggesting patterns twoand > 0.5), (r phase speed of 20 cm/s with periods tion tion patterns (dashed lines in Figure ast propagating signals with phase phase with signals propagating ast ing from 10 to 30 cm/s. cm/s. 1030 to ing from ficant ficant until 38°S (km 2100). These elations with point point with elations above the 1500 m isobath, in the the in isobath, m 1500 the above e 300 m isobath in 4d. isobath Figure m 300e o the faster propagation signals signals propagation faster the o types of signals: signals merely elf break, and slower signals in in signals slower and break, elf The correlation pattern with pattern correlation The Figure 5c). Figure s (dashed lines in Figure 4c). 4c). Figure in lines (dashed s 5d) . This propagating feature feature propagating This . 5d) Ω km 1600 and 2000 (43 and and (43 2000 and 1600 km nd with a phase speed ranging ed with these propagating propagating these with ed

of about 25 cm/s and a a and cm/s 25 about of Φ Φ Figure 4b), indicating indicating 4b), Figure (86W 53.35°S), (58.6°W, ’ ’ (r>0.5) suggested no no suggested (r>0.5) ’

Correlation patterns patterns Correlation Ω (Figure 4c): 4c): (Figure

20 20 Ω Ω ’ ’ slope velocities over the 300 m isobath with the zo the with isobath m 300 the over velocities slope wind-forced quasi-instantaneous response response quasi-instantaneous wind-forced vari velocity along-slope in-phase showed locations at lag 1 day peaked at the distinct locations indic showed patterns reminiscent of those observed in Fi wind stress at 53.5°S ( co highly was slope the along stress wind zonal The maximum variability (Figure 6b) near6b) variability (Figure maximum 38°S at Pa 0.05 to slope Patagonian the along north win mean the of intensity The Basin. Argentine deep t in and 52°S of south the to Pa) (>0.2 values mean The Southwest Atlantic undergoes strong westerlies pulwind to response 3.1 forced Coherent break shelf at signals Fastthe 3. wind also triggered the fast propagating signals de signals propagating fast the triggered also wind maps for the dates when the amplitude of the along along the of amplitude the when dates the for maps Along-slope velocity composites shown in Figures 7b non-propagating and signals thew propagations slow were shown) (not isobath m 1500 the over velocities In contrast, correlations of the zonal wind stress stress wind zonal the of correlations contrast, In (indicated gradientthe bathymetry of in direction andat 1000: 200,km 400, 800, 1000 and 6c)(Figure identified 4b in Figures and 4c). wave departOther This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Φ ) up to 47°S ( Ω Φ ) (not shown). Lagged correlations of the along- . . (compare pink dots in figure 4b and 6c)and 4b figure in dots pink (compare ated ated with pink dots in Figure 6c. These ses over the 25 years years 25 theover ses with stick plot in Figure 6c). 6c). inplot with Figure stick at ures wereuresbetween observed 0 km gure 4b. Interestingly, correlations parting from from parting (Figure (Figure 6a) with large wind stress nal wind stress at stress wind nal slope velocity filtered time series series time filtered velocity slope ations (Figure 4b), suggesting a suggesting 4b), (Figure ations . The zonal wind stress shows a a shows stress wind zonal The . -g were obtained from averaging . They corresponded to changes . They changes to corresponded Φ ere notere by forced wind. local the d stress decreases towards the the towards decreases stress d rrelated (r > 0.8) with the zonal zonal the with 0.8) > (r rrelated he southwestern portion of the of portion southwestern he not significant suggesting that that suggesting significant not ’ and ’ Ω ’ with the along-slope along-slope the with ’ Φ and Φ Ω (Figure 6c) 6c) (Figure (previously (previously . The . isobath. o slower a and break shelf the along one fast a 4d, propa two of superposition the with consistent were over over the 1500 m isobath between 47°S and showed showed a weak velocity signal all along the shelf b break, the analysis provided some insight in the mo n iswhich bathymetry, shelf with uniform coastline as idealized of spite In appendix). (see hypotheses slo a on waves frequency sub-inertial of structures (198 Chapman and Brink of theory linear the used We tutr wt cagn sg vlcte (iue b 7 (Figure velocities sign changing with structure Burdwood Bank Passage. As expected the composite ma composite the expected As Passage. Bank Burdwood seen was departure wave simultaneous A 7e). and 7b 6c corresponded to the locations of the largest alo are similar to those built from from built those to similar are anomalies at the around centered structure anticyclonic/cyclonic compo the with associated anomalies stress wind The consiste onesnegative the to sign opposite with an The maps positivecomposite of events (Figure 7 b c series.time p the for days (1400) 1350 about selected criterion at This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Φ ( 3.2 Idealized ocean response : cross-slope modalst cross-slope : ocean 3.2 response Idealized Ω and and Φ Ψ (Figures 7b and 7e). The wave departure locations epciey ecee oe tnad eito. (F deviation. standard one exceeded respectively) Φ . Composite maps exhibit complex cross-slope cross-slope complex exhibit maps Composite . Ψ (Figures 7d and 7g). These observations ng slope velocity anomalies (Figures reak reak intensified near ot the case of the Patagonian shelf shelf Patagonian the of ot case the dal dal structure of trapped waves. We nt with wave dynamics. dynamics. withwave nt Malvinas Islands with zonal wind zonal with Islands Malvinas ositive (negative) events for each each for events (negative) ositive gating patterns as seen in Figure Figure in seen as patterns gating -g). The composite built from from built composite The -g). d) have spatialsimilar structures ne offshore above the 1500 m m 1500 the above offshore ne sumptions such as a straight straight a as such sumptions on the western side of East of of East of side western the on ping bottom under idealized idealized under bottom ping sites exhibited a well-defined well-defined a exhibited sites 7), which provides the modal modal the provides which 7), ps built from from built ps ructure ructure identified identified in Figure Ψ igure 7a). This This 7a). igure Ω , plus a signal time series series time Ψ

northward northward (Figure 9). The theoretical dispersion cu waves trapped shelf-break with associated relations consiste patterns along energy showed isobath m 300 300 m isobath. isobath. m 300 est velocity and vertical to (not shown) composites cm 1 of order the of velocities slope across to led suggested a scaling factor of 6 106 of factor scaling a suggested composi the in maxima velocity 1989); (Brink factor i mode theoretical The km. 2500 to 500 from varying 5 between ranging periods with waves for ) cm/s 300 curves provided theoretical phase velocities matchi reminiscent of theoretical modes 2, 3 and 4 (see ap veloc three The 8). (Figure isobath m 300 the above significant peaks (above the standard deviation) in composi velocity built we sections, three the Along appe (see slope lower on the intensified bottom and barot nearly are modes the sections cross-slope the modes and their dispersion curves for the 3 section bathymet abrupt an showing 42°S at one last the and 47°S atone the second m), (2000 shallow relatively where 51°S at one first the : slope Patagonian the computed modal cross-slope of structures trapped wa This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article 3.3 Period-wavelength spectrum of along-slope veloc along-slope of spectrum Period-wavelength 3.3 The period-wavelength spectrum of along slope veloc slope along of spectrum period-wavelength The 8 . Applying the factor scale to the theoretical mode theoretical the to scale factor the Applying . /s, consistent with the across slope slope across the with consistent /s, the along-slope velocities at 100 m pendix). Mode 2, 3 and 4 dispersion rves rves computed for several latitudes imates of the order of 5-20 m/d. 5-20 of m/d. the order of imates s s are shown in the appendix. Along ng the observed one (about 140 to the slope is gentle and the bottom bottom the and gentle is slope the tes corresponding to the dates of dates the to corresponding tes where the upper slope is steeper steeper is slope upper wherethe ndix). ndix). of modes 2, 3 and 4 propagating propagating 34and 2, modes of ropic, trapped at the shelf break break shelf the at trapped ropic, ity composites featured patterns patterns featured composites ity and 110 days and wavelengths wavelengths and days 110 and s defined within a multiplicative multiplicative a within defined s ves ves along three sections across te and the theoretical mode mode theoretical the and te nt with theoretical dispersion dispersion theoretical with nt ry (Figure 8). The 4 gravest gravest 4 The 8). (Figure ry ities at 100 m above the the above m 100 at ities ities at 100 m above the the above m 100 at ities

negative phase the onshore jet core velocity dimini velocitycore onshore jet phase the negative (Figur surface the near cm/s 40 reached jet onshore onshore strong jet at 47°S where the two isobaths c b two The diverge. isobaths m 500 and 300 the where je onshore The 6c). Figure in (identified departure assoc were break shelf the at maxima velocity slope to 55°S from break shelf the along jet onshore the cor wave the of phase positive The jet. onshore the between relation potential the investigated We 1b). Burwood of west from isobath m 300 the follows SAF associa jet onshore the while core, current largest correspon and isobath m 1500 the straddles jet main South of 42°S, the MC is organized in two relativel onshore the onwaves theof shelf-break Impact 3.4 withperiod increasing wavelengths with 7 in Figure built the corresponding composites (not shown). We (10- bands period three in signals SBTW filtered We dynamics. insight the into theprovides theory constan infinite an of hypothesis the although that with different bottom steepness and mean flows (bla oiiengtv sga ( 4 m oe te continen the over cm) 4 (> signal positive/negative The GLORYS12 SLA composite maps built from velocity from built maps composite SLA GLORYS12 The shelf-b fast anomalies accompanying 3.5surface Sea This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article y stable jets (Piola et al., 2013).The ted with the northern branch of the the of branch northern the with ted shes (Figures 10c and and 10d). 10c (Figures shes t slope is far from being satisfied, satisfied, being from far is slope t onverge (Figure 10a). At 47°S, the theory. from as expected s ck ck and grey lines in Figure 9) show t split into two branches at 51°S 51°S at branches two into split t responded to an intensification of intensification an to responded the fast propagating waves and and waves propagating fast the jet jet obtained similar patterns to those 47°S (Figure 10 a). Local along- Local a). 10 (Figure 47°S 40, 30-90 and 80-110 days) and and days) 80-110 and 30-90 40, reak waves waves reak e 10b). In contrast, during the the during contrast, In 10b). e iated with the regions of wave wave of regions the with iated Bank at 55°S to 44°S (Figure 44°S to 55°S at Bank tal shelf consistent with the the with consistent shelf tal ds to the main SAF and the the and SAF main the to ds ranches merged in a single single a in merged ranches time series at at series time Φ shows a a shows

45 cm/s (18 cm/s) for the along-slope velocity and and velocity along-slope the for cm/s) (18 cm/s 45 t filtered day (30-90) 10-40 The years. 25 the over velocity the of 87% explained series time filtered ye for 12 Figure in shown is decomposition SLA and (2-4) predicted by Brink linear theory (Figure A5). (Figure theory linear Brink by predicted (2-4) composites SLA The 11a). (Figure days 10 than less Stronger composite SLA patterns were observed on th on observed were patterns SLA composite Stronger creating of phase pattern negative and withpositive the associated anomaly wind anticyclonic/cyclonic the location location the an 30-90 10-40, ranges: period overlapping three in filtere band-pass we periods, these with associated all along the slope (Figure 2). To distinguish the SLA spectra showed energy distributed in distinct p Malvinas theof the core in Velocityvariations 4. 4d. in Figure of reminiscent offshore, slightly centered 42°S to 2.5 cm) and a somewhat stronger mesoscale structure (Figures 11d and 11g) showed low values on the cont at values SLA synoptic however were values SLA composite break shelf the along All 11f). and 11c (Figures This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Ω ’ at 47°S, a central position along the slope. An exa An slope. the along position central a 47°S, at Ω could reach peak values larger than 5 cm lasting lasting cm 5 than larger values peak reach could different different spatial patterns (wavelength) Current Current variance (73% of the SLA variance) variance) SLA the of (73% variance In contrast, SLA composites for for composites SLA contrast, In slow propagating signals observed observed signals propagating slow imes series varied over a range of of range a over varied series imes eriods ranging from 10 to 110 days the wave (Figures 11b and 11e). 11e).wave and 11b the (Figures d along-slope velocities and SLA SLA and velocities along-slope d inental inental shelf (amplitude less than d 80-110 days. We focused on on focused We days. 80-110 d of 14 cm (10 cm) for the SLA SLA the for cm) (10 cm 14 of were consistent with the modes modes withthe consistent were of opposite sign (3.5 cm) close ar 2013. The sum of the three three the of sum The 2013. ar e shelf in the composite for for composite the in shelf e ml o te re o 2 cm, 2 of order the of small convergence/divergence convergence/divergence mple of the velocity the of mple Ψ Ω

from from corre featured diagrams The 13. Figure in shown are anomali velocity along-slope of correlations Lagged an velocities 10inalong-slope thecm of amplitude provi filter day 80-110 The 12b). and 12a (Figures 1429, 1461 and 1415 days were considered for the 20 and 140 km between changed velocities band-passed three The 13c). (Figure km 1500 and 300 km between cm/s 1 pass withdelivered waves of afilter about period 1 (Figure (43°S) 1500 km and (49°S) 600 km between filter provided waves with a period of about 60 day 13a (Figure 1400 and 700 km between cm/s 1 25± of day band-pass filter selected waves with a period o the for about days 100 andsignals band-passed day half) was about 10 days for the 10-40 day band-pass of time characteristic The 13c). 13a,13b, (Figures amplitude at amplitude Composite maps (Figure 14) were built selecting the b the Confluence. from signals waves interferences and propagating suggested diagrams composite lagged Bet Confluence. Brazil-Malvinas the with associated in We patterns. propagating southwestward indicated Beyond increased. slightly velocities phase There, steepens slope bottom and Northeast) to North (from This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Ψ Ω ’, Figure 5a), at a location where the shelf-break shelf-break the where location a at 5a), Figure ’, ’ suggesting continuous damping of the propagating si propagating the of damping continuous suggesting Ω ’ larger than the band-pass velocity standard deviat standard velocity band-pass the than larger 100 days100and a phase of 14±speed s s and a phase speed of 20± 2 cm/s f f about 20 days and a phase speed d 4 cm in the SLA. in thecm SLA. 4 d ded a rather regular signal with an an with signal regular rather a ded days with a band-passed velocity damping (amplitude reduced by by reduced (amplitude damping es at 100 m for each filter period filter each for m 100 at es ed signals, 20 days for the 30-90 lations decreasing with distance distance with decreasing lations larger period signals. The 10-40 10-40 signals. The period larger -, 60- and 100-day period waves

ween km 1600 and 2000, the the 2000, and 1600 km ween (Figures 13a, 13b and 13c). 13c). and 13b 13a, (Figures km 2000, lagged correlations correlations lagged 2000, km 0 and 1800 (between point C C point (between 1800 and 0 abruptly changes orientation orientation changes abruptly ). The 30-90 day band-pass band-pass day 30-90 The ). 3b). The 80-110 -day band- -day 80-110 The 3b). terpreted those as signals signals as those terpreted correlation patterns for the the for patterns correlation etween the northward northward the etween gnals along the slope slope the along gnals ion (Figure 12a): 12a): (Figure ion model. In contrast, synoptic values of SLA could re could SLA of values synoptic contrast, In model. waves had shorter wavelengths, smaller widths, and we waves period 20-day the for composite SLA the in clearly showed the two pathways from the Malvinas P composites the in amplitude cm 3 to 2 of anomalies wi associated were waves period 100-day and 60- The Confluence. the comingfrom o indication an patchy, became waves day 100 the of weakened and stretched along for the shelf break while maps composite the in signal the 43°S, of North et2016). al., (Artana SRP observations showing the SAF crossing the North This Sco passages. two the through proceed may Passage suggestin patterns showed Plateau Malvinas the over a velocity 1a).The (Figure (SRP) Passage Rock Shag connect the toPassage Drake the Basin: E Argentine to 50 km (Figures 14 a-e; 14f-j; 14 k-o). Two deep 1500 m isobath from the Plateau and the 2800 m isob w 13c) and 13b 13a, Figures in 600 km (around 49°S two The 1a). (Figure Escarpment Malvinas the along one and Passage Drake northern the from one paths, la 49°S, Upstream k-o). 14 f-j; 14 a-e; 14 (Figures 40 25, about of cores narrow with mode of structure 13 respectively(Figure km 1200 and 1000 450, about waves period and60- 100-day The 20-, respectively. This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

passages passages in the North Scotia Ridge the the signals in the composite maps gged composites suggested two suggested composites gged ath ath from the Escarpment reduces were more rapidly damped in the had along-slope wavelengths of of wavelengths along-slope had ach 7 cm for the 20-day period period 20-day the for cm 7 ach ast Burwood of Bankand (EBB) lateau and Escarpment. Signals tia tia Ridge through either EBB or , and 50 km width respectively respectively width km 50 and , ), and featured an across-slope across-slope an featured and ), contributions combined around around combined contributions (Figures 15b and 15c), which which 15c), and 15b (Figures nomaly in the composite maps maps composite the in nomaly here the distance between the the between distance the here re blurry (Figure15a) as these these as (Figure15a) blurry re basin argentine deep the from the 20- and 60-day waves waves 60-day and 20- the th consistent elongated SLA SLA elongated consistent th f interferences with signals signals with interferences f g that waves from Drake Drake from waves that g was in agreement with with agreement in was over the 25 years (Figure 10). 10). (Figure years 25 theover int the withassociated 1), (Figure the which SAF-N varied impacted waves The 7a). (Figure depth m 100 velocit Along-slope . 6c) (Figure orientation break correspondin sites distinct from departed cm/s) 300 wave fast The 7). and 6 (Figures break shelf the of along-slope velocity variations and trigger fast pr 47° of south variations stress wind zonal large The 10 cm/s from ranging velocities withpropagation MC and break, shelf the along all cm/s 300 to cm/s 140 signal propagating fast break, shelf the at 47°S of s of types three indicated years 25 over Statistics scalesat time more energywith however altimetry, slope, GLORYS12 reproduced peaks in SLA energy comp 10 than less periods at energy lacked GLORYS12 that for tests stringent are region Confluence Malvinas (variable Comparisons with current-meter mooring data from th break shelf Patagonian complex the along at variations velocity examine to GLORYS12 used We discussion Summary and 5 12b). (Figure fo cm 2 and waves period 60-day the for cm 5 waves, This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article opagating opagating waves at specific locations ignals: signals in phase to the south south the phase to in signalsignals: y anomalies exceeded 15 cm/s at cm/s 15 exceeded anomalies y model performance. They showed showed They performance. model s (phase speed between 140 and and 140 between speed (phase s s with phase speed ranging from from ranging speed phase with s from from 0 30 to cm/s at m 100 depth days. than20 shorter slower signals in the core of the of core the in signals slower S were shown to force in-phase in-phase force to shown were S g to abrupt changes in the shelf shelf the in changes abrupt to g to 30 cm/s. to 30 cm/s. e slope near the complex Brazil- days (Figure 3). All along the the along All 3). (Figure days r the 100-day period waves waves period 100-day the r periods larger than 10 days 10 than larger periods arable arable to those from satellite direction and steepness). steepness). and direction ensity of the inshore jet jet inshore the of ensity fulfilled along the Patagonian shelf break, shelf Patagonian the along fulfilled simil with straight ascoastline a such assumptions Although Brink’s model is too idealistic (e.g., Bru be could maps altimetry satellite present waves in (Figure days 20 than less lasting cm 5 than larger brea shelf the at SLA Synoptic cm). 3 of (composite an cm) 6 to up composite (SLA shelf continental the t generating wind the to response SLA GLORYS12 The cross-slope mode 2 or 3 with scales ranging from 25 1 and 1000 450, of wavelengths along-slope cm/s, 14 the days, 100 and 60 20, about of periods to correspond of core the in waves propagating of types Three (2015). tempor eve and upwelling observed the of those spatial with consistent had GLORYS12 in waves fast break requiring vertical velocities of the order of 13-29 upwellingof events 5 lasting to 10 days extending Short-term moorings above the 200 m isobath at 41°S nutr of transport enhance to contribute could waves (reverse phase positive the in cm/s 1 of velocities positive vertical velocities of the order 5 to 20 m Scali cm/s). 2 to (1 velocities cross-slope inshore stage featured increased northward along-slope velo st (Fig model Brink’s in 4 spatial to 2 mode a to their corresponded and speed phase Their waves. those This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

it provided guidance to the interpretation of of interpretation theto guidance provided it /day associated with inshore horizontal m/d (Valla and Piola, 2015). The shelf- nner et al., 2019) and requires several over 500over at km and shelf-break the in negative phase). Thus, the fast fast the Thus, phase). negative in challenging.· challenging.· ar slope bathymetry, which are not not are which bathymetry, ar slope ng with Brink’s theory predicted predicted theory Brink’s with ng ients from the MC onto the shelf. shelf. the onto MC the from ients city city (5 to 20 cm/s) associated with to 50 These km. waves were not phase speeds of 0.26, 0.19 and and 0.26, 0.19 of speeds phase nts described in Valla and Piola Piola and Valla in described nts k at 47°S reached peak values values peak reached 47°S at k d smaller along the shelf break break shelf the along smaller d and 43.8°S provided evidences 11). Therefore, tracking these these tracking Therefore, 11). ures 7, 8 and 9). Their positive positive Their 9). and 8 7, ures 200 km respectively and to a a to and respectively km 200 MC were identified. They They identified. were MC he fast waves was large on on large was waves fast he ructure across the slope slope the across ructure al velocity structures structures velocity al of the waves observed in the core of the MCtheneedfu of in the core observed waves theof mecha forcing The 14). (Figure Escarpment Malvinas th to back tracked were waves these and with 60- associated 20-, the for cases 1415 and 1461 1429, from anoma velocity Composite winds. local the by forced (Lebed Malvinas Current and the Brazil encounter of waves trapped that suggested also works Theoretical branch of the MC at 37°S (Artana et al. 2019) could a series time velocity the in and 41°S at transport 30-110 a in peaks energetic significant The 2018a). detached from the PF that rel propagate northward along were 41°S at MC the in maxima transport Extreme Co Brazil-Malvinas the of location and transport MC reflection are beyond the scope of this paper. The wi interaction effects, damping signals, other with su processes linear Non Confluence. Brazil-Malvinas pe with interacted they where 41°S to up propagated characteris changed MC the of core the in waves The This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article ssociated with the subducted inner inner subducted the with ssociated impact impact of the waves trapped on the be associated with trapped waves. th the mean flow, refraction and and refraction flow, mean the th day period band found in the MC inthe found band period day rther investigation. ev and of Nof, 1996). Nof, of ev and the 400m isobath (Artana et al., investigation. under is nfluence lies of the order of 6 cm/s (built cm/s 6 of order the of lies could affect the position of the the of position the affect could ch as scattering, interferences interferences scattering, as ch nisms and the upstream paths paths upstream the and nisms tics at 43°S, accelerated and and accelerated 43°S, at tics train cmn fo the from coming rturbations e Drake Passage and the the and Passage Drake e ated with cyclonic eddies eddies cyclonic with ated 100-day period waves), waves), period 100-day

The structure of the modes is dependent on the Burg the on dependent is modes the of structure The A1.f). (Figure Current GLORYS12, we chose an idealized stratification weak v the in mode the intensified structure two-jet the (Fig section the on depending jets northward two or mean idealized the Current, Malvinas the of values and 42°S) shown in Figure A1.a (pink, red and blue) too the applied We wavenumber. and frequency given rm otm oorpyhx,ofhr stratificatio offshore h(x), topography bottom from toolb Chapman’s and Brink (h(x)). topography bottom (N(z stratification uniform horizontally rotation, invis linear, a considered (1987) Chapman and Brink model linear Appendix: km), km), the theory provided waves with periods rangin Pata the of length the with (consistent km 1500 For sec three the for velocities vertical with positive a inshore featured 3 mode The A2). (Figure sections near anomalies velocity larger featured modes three sugge one than lower was sections cross-slope three large (S>1) S value of corresponds slow-propagat to S propagating barotropic shelf-waves where the of rotati values Small A1.e). (Figure parameter Coriolis Br coastal mean the N m/m, in slope cross-shore the This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

Trapped waves at 51°S, 47°S and 42°S from Brink and Brink from 42°S and 47°S 51°S, at waves Trapped tions (Figure A3). A3). tions (Figure )), and an alongshore non varying varying non alongshore an and )), icinity of the jets. Similarly, following following Similarly, jets. the of icinity n Nn g between 1 to 30 days and phase . . Following GLORYS12 mean flow on on dominates over gravity, while a gonian slope of the order of 3000 of order the of slope gonian flow, V(x,z) is composed of one one of composed is V(x,z) flow, ing baroclinic waves. baroclinic alonging S the ure A1.b-d). Taking into account account into Taking A1.b-d). ure ünt-Väisälä frequency and f the f and frequency ünt-Väisälä and uniform along the Malvinas cross slope velocity associated associated velocity slope cross er number : S = ( = S : number er ox computes modal structures structures modal computes ox the shelf break for the three three the for break shelf the 2 lbox to 3 sections (51°S,47°S (51°S,47°S sections 3 to lbox z, en lw((,), o a for (V(x,z)), flow mean (z), tn brtoi mds The modes. barotropic sting (S<1) correspond to fast fast to correspond (S<1) cid problem with constant constant with problem cid Chapman (1987) (1987) Chapman α

Ν /f) 2 with α

https://d cf. ; https://doi.org/ and https://doi.org/10.17882/51483 (www.seanoe.org SEANOE at available http://marine.copernicus (CMEMS; Service Monitoring C at available are outputs model and data satellite P CNES a from Artana Camila and Université acknowled Sorbonne Poli Léa DSP/OT/12-2118. EUMETSAT/CNES to (Centre constant for Spatiales) d’Etudes s National for a number of constructive comments and suggestio We thank the Editor, Don Chambers, an anonymous re Acknowledgments: (Figure50 A4.b). to cm/s 300 from A4.b (Figure waves 2-4 mode dispersive low predicts 600 between ranging wavelengths realistic probably Fig and A4.a (Figure cm/s 800 and 30 between speeds This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article 10.17882/51492). 10.17882/51492). upport. This This upport. astudy is contribution ns. We are grateful to the CNES opernicus Marine Environment Environment Marine opernicus and 1500 km for which theory which for km 1500 and viewer viewer and Josep Lluís Pelegrí ) with phase speeds ranging ranging speeds phase with ) .eu/) and the in situ data are are data situ in the and .eu/) ure A4.b). We focused on on focused We A4.b). ure ostdoc Scholarship. The The Scholarship. ostdoc oi.org/10.17882/51479, oi.org/10.17882/51479, ges support from from support ges rn, . . 18) A oprsn f og osa t coastal long Physical Oceanogr Journal of Peru.of off observations comparison A (1982). H. K. Brink, doi.org/10.1016/j.ds https:// 2533–2554. 58(25-26), T II: Part Research Sea Deep perspective. satellite crui ANT-XXIII/3 the during Passage Drake eddies in Sennéchael, & A., Renault, C., Provost, N., Barré, https://doi.org/10.5194/os-15-1091-20191109. m altimetry ocean of resolutions the On (2019). al. Taburet I., M. Pujol, C., Ubelmann, M., Ballarotta, https://doi.org/10.1029/2019JC015289 Geop of Journal Reanalysis. Ocean Mercator of Years 5261– 123, Bra the With Confluence the at Current Malvinas The Oceans, Artana C., Provost C., Lellouche Research. J.-M. , Rio M.-H., Geophysical https://doi.org/10.1029/2018JC013887 of Journal M and floats, Argo altimetry, satellite by revealed Surf System: Current Malvinas the of Fronts (2018). Lellouche,Y.-H., C., Garric, J.-M., Artana,Park, s doi: 4872,4854– Oceans, 121, Geophysical Research, and floats Argo from variability Current Malvinas A. Saraceno, M. Koenig, Z. Ferrari, R. C., Artana, https://doi.org/10.1029/2019JC0 124, e2019JC015878. mapped sea surface height from altimetry. Journal o rhr M R, i Z, F, L. Fu, & Z., Li, R., M. Archer, : References This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article ‐ L. (2020). Increasing the space–time resolution of of resolution space–time the Increasing (2020). L.

G., Koenig,al. G., et Sennéchael,Z., N., Ferrari R. & Sennéchael N. (2019). , G., Fournier, F., Legeais, J. F., et F., J. Legeais, F., Fournier, G., , ercator operational model outputs. outputs. model operational ercator aps. Ocean Science, 15(4), 1091– 15(4), Science, Ocean aps. r2.2011.01.003 r2.2011.01.003 f f Geophysical Research: Oceans, N. (2011). Fronts, meanders and and meanders Fronts, (2011). N. opical Studies in Oceanography, Oceanography, in Studies opical R. Piola, and C. Provost (2016). (2016). Provost C. and Piola, R. aphy, 12, 897–913. 897–913. 12, aphy, ace and subsurface expressions expressions subsurface and ace se in January–February 2006: A 2006: A January–February in se zil Current: Inferences From 25 25 From Inferences Current: zil 10.1002/2016JC011889. 10.1002/2016JC011889. 15878. 15878. atellite altimetry, Journal of of Journal altimetry, atellite hysical Research, Oceans, Oceans, Research, hysical apd ae hoy with theory wave rapped 5285. 5285. Science, 14, 1093– 1126. https://doi.org/10.5194/os 1093– 14, Science, global ocean monitoring and forecasting real-time 1 Remy, E., & Le Traon, P.-Y. (2018). Recent updates Ocea H F., Gasparin, R., Bourdalle-Badie, C.-E., Testut, Research, Ga O., Galloudec, Le E., Greiner, J.-M., Lellouche, Geophysical https://doi.org/10.1016/S0967- I, Part Sea Research of curre boundary of Collision D., Nof and I. Lebedev Journal https://doi.org/10.1002/2017JC013340 variation. of and current-meter velocities in the Malvinas Curren Pr & A.R. Piola M., Saraceno C., Artana R., Ferrari https://doi.org/10.5194/os-9-1-2013 18.1– 9( 1), CORA The 2013). salini and temperature ocean in-situ of diagnostics ( Y. P. Traon, Le & S., Pouliquen, Monte Boyer N., Ferry, C., Boone, S., Guinehut, C., Cabanes, C., Grouazelm, A., von Schuckmann, K., Ham https://doi.org/10.1175/JPO-D-18-0112.1 2216, wave theory to High Scattering regions. Journal of Applicat (2019). Lwiza K.M.M. Rivas, D. K., Brunner 1011–1019, Physical Oceanography, of Brink, K. H. (1989). Energy conservation in coastal Hol MA: Hole, pp).Woods 122 Rep.Woods WHOI-87-24, cont the over motions wind-driven and waves trapped Brink, K. H., Chapman,& D. for Programs C. (1987). This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

16. 16. -trapped -trapped wave calculations. Journal ernandez, O., Levier, B., Drillet, Y.,Drillet, Levier, B., ernandez, O., ty measurements. Ocean Science, OceanScience, measurements. ty Physical Oceanography, Physical49, Oceanography, 2201- t at 41°S: Comparisons and Modes /12° high resolution system. Ocean rric, G., Regnier, C., Drevillon, M., Drevillon, C., Regnier, G., rric, ovost C. (2017). Satellite altimetry altimetry Satellite (2017). C. ovost nts: beyond a steady state, Deep Deep state, steady a beyond nts: on the Copernicus Marine Service -2018-15 -2018-15 0637(96)00127-6 gut, C., Carval, T., Reverdin, G., G., Reverdin, T., Carval, C., gut, computing coastal- of properties ion of classical coastal trapped trapped coastal classical of ion inental shelf and slope (Tech. (Tech. slope and shelf inental on, M., Turpin, V., Coatanoan, e Institution. eInstitution. dataset: Validation and and Validation dataset:

ns, F., F., Faugere, Y., and Dibarboure, G. (2019). DUACS D Puj M., Ballarotta, A., Sanchez-Roman, G., Taburet, https://doi.org/10. SEANOE. Reanalysis. Dataset for Szekely, T., Gourrion, J., Pouliquen, S., & Reverdi https://doi.org/10.1029/2008JC004882. C02002. aelt atmty n sas sibad bathymetry shipboard sparse and altimetry satellite Bathy 1994). ( T. D. Sandwell, and F., H. W. Smith, doi:10.1029/2005JC003244. 111,C05021, Oceans, Jo data, SeaWiFS on based Patagonia off variability Garcia, and M., Charo, R., A. Piola, I., S. Romero, 2016 https: 1090. 1067– 5), 12( Science, Ocean years. 20 Research, altimet multi-mission new Geophysical The DT2014: DUACS (2016). of S., Dupuy, G., Y.,M.-I., Faugère, Taburet, Pujol, Journal https://doi.org/10.1002/jgrc.20170 Current. Malvinas Saraceno M. & Palma E.D. B.,C., Franco A.R., Piola Re Geophysical of https://doi.org/10.1029/2017JC013666 Journal variability. salinity and and C. I. Artana (2018). Malvinas Current at 40-41° Paniagua G.F., Saraceno M., A.R. Piola, R. Guerrero rnpr sne coe 19. ora o Geophysica of Journal 1992. October since t transport in Variations (2009). C. Provost, & A., Spadone, doi:10.1029/94JB00988. 21824, 21803– This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Pelloquin, C., Ablain, M., & Picot, N. Picot, N. M., & Pelloquin,Ablain, C., n, G. (2016). CORA, Coriolis, Ocean S: S: First assessment of temperature 17882/46219 17882/46219 ol, M.-I., Legeais, J.-F., Fournier, J.-F., Legeais, M.-I., ol, , C. Provost, R. Ferrari, L.S. lago C. A. E. (2006). Chlorophyll-a Chlorophyll-a (2006). E. A. C. , T2018: T2018: 25 years of reprocessed he Malvinas Current volume volume Current Malvinas he urnal Geophysical Research, Research, Geophysical urnal . epy. Res. Geophys. J. metric prediction from dense dense from prediction metric //doi.org/10.5194/os-12-1067- er data set reprocessed over over reprocessed set data er search, Oceans, 123, 8, 8, 123, Oceans, search, (2013). Multiple jets in the the in jets Multiple (2013). Rsac, Oceans, Research, l , 99( B11), B11), 99( , Oceans, 114 , , 0485. Malvinas Region, Journal of Physical Oceanography, Remot (2001). Meredith M. & Provost, C. F., Vivier, Research doi:10.1029/1999JC900163. Geophysical of Journal Vivier, F., & Provost, C. (1999). Direct velocity doi:10.1002/2015JC011002. Patagonian upweshelf break, Journal of Geophysical Rese of Evidence (2015). Piola R. A. and D., Valla, 15-1207-2019. 1207– 15, Sci., Ocean products, altimetry level sea This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

, Oceans, 104( C9), 21083– 21103, 21103, 21083– C9), 104( Oceans, , measurements measurements in the Malvinas Current, 1224, https://doi.org/10.5194/os- 1224, 31, 892–913, doi: 10.1175/1520- e and local forcing in the Brazil Brazil the in forcing local and e arch, arch, Oceans, 120, 7635– 7656, lling events at the northern northern the at events lling d) mean values of surface chlorophyll-a concentrati satellite data. Note the long continuous high value high continuous long the Note data. satellite (color) from GLORYS12 (color) from surfac mean and (arrows) velocities surface mean b) isobath. corres isolines White (SRP). Passage Rocks Shag and (WBB), Bank Burwoodof West indicated: are Passage the connecting passages Three 1994). Sandwell, and fro m) (in Atlantic Southwest the of Bathymetry a) : Figure Captions correspond to the location of the moorings. of the location correspond to altimetry DUACS product b) from Mercator reanalysis 17 and 300 between the band a longitude in averaged a as spectra preserving variance anomaly level Sea 2: Figure 4 deployments. mooring successive at segment white The 2017). al., et Ferrari in as as in Barré et al., 2011), that of the Brazil Curr with (SAF) SAF main the of that line, dashed black SA the of branch northern the of locations mean The (2002-2017). c) mean surface EKE from GLORYS12 over the period 1 the over GLORYS12 EKE from mean c) surface This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected

Accepted Article : Figure 1

over the period 1993-2017. 1993-2017. period over the ent front (BCF) with a cyan line (defined on (in mg/m s (>2.5 mg/m (>2.5 s m ETOPO6.2 (update from Smith Smith from (update ETOPO6.2 m a continuous black line (defined (defined line black continuous a GLORYS12. White lines at 41°S F (SAF-N) is represented with a a with represented is (SAF-N) F 00 m isobaths) a) from satellite satellite from a) isobaths) m 00 1°S in a) marks the sites of of sites the marks a) in 1°S ucin f aiue SA was (SLA latitude of function East of Burwood Bank (EBB), (EBB), Bank Burwoodof East Argentine Basin to the Drake Drake the to Basin Argentine e velocities intensity in cm/s cm/s in intensity velocities e 993-2017 in (cm/s)993-2017 pond to 300m and 1500m 1500m and 300m to pond 3 ) derived from MODIS 3 ) at the shelf break. shelf the at ) 2

Only significant correlations (above 90% confidence (above correlations Only significant 1a). Color bar in cmin bar Color 1a). The gap between 50.5°S and 48°S corresponds to a re d) along-slope velocity correlations with correlations velocity d) along-slope and a) points along the slope used for thefor correlations used slope along thea) points isobath. 300 m the depth above m 100 fi high-pass 110-day of diagrams correlation Lagged 4:Figure bathymetry. ETOPO from bathymetry the is line Black lisibility. displ are They line). dashed (red location same the fil low-pass 5-day a with smoothed been have series fr and green in 2014-2015 blue, in 2001-2003 black, m current each for ellipses variance and Flow Mean 3: Figure 90%a c tolines correspond (black). Dashed product s for and (red) GLORYS12 for 43°S and 48°S between c) along-slope velocity correlations with correlations velocityalong-slope c) 0 day. lag atobtained locations indicate dots Pink days. in lag is y-axis along-slope along-slope velocity with correlations This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Ψ (41°S). Red line is the 300 m isobath. Background Background isobath. m 300 the is line Red (41°S).

2 . c) Sea level anomaly variance preserving spectra preserving variance anomaly level Sea c) . Φ . . X-axis is along-isobath distance from 53.5°S, Ω Ψ (axes as in b) b) as in (axes (axes as in b) b)as in (axes where maximum correlations were were correlations maximum where with locations limit) are colored. are colored. limit) onfidence limit. limit. onfidence ter. 0M1 and 1A1 are both from from both are 1A1 and 0M1 ter. om GLORYS12 in red; all- time all- red; in GLORYS12 om 6.2 and red line is the model model the is line red and 6.2 eter at 41°S from 1993-1995 in 1993-1995 from 41°S at eter aced on the figure for sake of of sake for figure the on aced gion gion with zonal isobaths (Figure ltered along-slope velocities at at velocities along-slope ltered atellite altimetry DUACS DUACS altimetry atellite is bathymetry (in m). b) b) m). (in bathymetry is Φ (53.5°S), (53.5°S), averaged averaged Ω (47°S) (47°S) at 100m depth over isobath 1500 m (in the core of t of core the (in m 1500 isobath over depth 100m at high-pa 110-day of diagrams correlation Lagged b-d) (in m). bathymetry Ω Ω a. 23±c) 4:in Figure as estimated 2 velocities Phase c. a) points along the slope used for thefor used correlations slope along the a) points 5:Figure 35 d) ± bothdashed ±210 and segments, for 3cm/s estimates of the phase velocities b) 250 ± 50 cm/s maximum of fit linear a to correspond lines Dashed 1500 m isobath are not significant (not shown). X a X shown). (not significant not are isobath m 1500 shown are correlations significant Only reanalysis. over isobath m 300 above m 100 at velocities slope b. Pa) (all in intensity is background Φ isobath, y-axis is lag in days and vertical lines c day. Phase velocity were estimated as in figure 4 : as in figure estimated were day. velocity Phase wit correlations where locations indicate dots Pink This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted 6: Figure Article ’ (59.2°W, 47°S) and and47°S) (59.2°W, ’ ’ (c),’

, ,

Ω and Lagged correlations between the zonal wind stress a Mean wind stress (1993-2017) from ERA-interim, arro Standard deviation of the zonal wind stress. wind zonal stress. the of Standarddeviation Ψ ’ (d). X-axis is distance along the isobath and Y-a and isobath alongthe distance X-axis is (d). ’ Ψ shown in Figure 6a) and b). b). 6a)Figure and in shown Ψ ’ (56°W, 41°S), blue line is the 1500 isobath. Back isobath. 1500 the line is blue 41°S), (56°W, ’ orrespond to location of points A,B,C,D, with location h the wind were maximum at lag 1 1 lag at maximum were wind the h and 167± 15 cm/s c) 156 ± 15 cm/s between 108 cm/s and 241 cm/s and cm/s 241 cm/s 108between cm/s d) 30± cm/s 2 cm/s . Lagged correlations above the the above correlations Lagged . he MC) considering point point considering MC) he xis is distance from from distance is xis correlations. The slopes provide provide slopes The correlations. ss filtered along-slope velocities velocities along-slope filtered ss 50 cm/s. 50 cm/s. the 25 years of GLORYS12 GLORYS12 of years 25 the t t xis is lag in days. days. in lag is xis Φ ws represent direction and (53°S) and ocean along- Φ ’ (58.6°W, 53.35°S), (58.6°W, ’ Φ along the along ground is is ground Φ ‘(b), dates with velocities exceeding the standard deviat standard the exceeding velocities with dates b, c, and d: along-slope velocity composites at 100 standard theto areacorresponds and shaded in cm/s 300 m isobath at fil high-pass 110-day along-slope of series Time a: 7: Figure . north the represents Arrow in Black showna). alon gradient bathymetry the represents plot Stick isobath exceeds the standard deviation. deviation. the standard exceeds isobath v filtered the when dates the for phase e) negative d-e) Composite of along-slope filtered velocity alo deviation. standard exceeds the isobath m filter the when dates the for phase c) negative and alo velocity along-slope filtered of Composite b-c) isobathexceeded m 300 theover m 100at velocities to g) for comparison with theory. They were built a model. GLORYS12 velocity composites (in cm/s) were a) Location of the three sections examined in the a 8:Figure phase. negative b-c-dthe for andas g :e,f Same anomaly composite. indicate e) and b) on arrows The phase). (positive This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Ω for 2 years (2016-2017 as an example for sake of c veraging veraging fields at dates when filtered ng the red section for positive d) and ppendix using Brink and Chapman’s m. They were built considering the ng the blue section for positive b) b) positive for section blue the ng ed velocity at 100 m over the 300 300 the over m 100 at velocity ed tered velocity at 100 m above the the above m 100 at velocity tered elocity at 100 m over the 300 m m 300 the over m 100 at elocity ion at ion h soea ahclrd dot colored each at slope the g the standard deviation. deviation. standard the deviation. deviation. the corresponding wind stress stress wind corresponding the produced produced along the sections (b Φ , Ω and Ψ larity).Units larity).Units are , respectively respectively , b-c-d) SLA for the positive phase at phase at positive thefor b-c-d) SLA Only inarecm. Units 7. in shown Figure composites a (SLA) anomalies level sea model of Composite b-g) a) Time series of GLORYS12 SLA above the 300 m isob300 m above the SLA GLORYS12 of seriesa) Time 11:Figure in cm/s. Colorbar correspondi 47°S at section velocity d)slope Along phase. negative a) Samethe for c) correspondi at section 47°S velocity b) Along-slope b. shown is section vertical 47°S 7b)s.THe slope along of composite the twice plus flow (Mean a) Along slope velocities corresponding to the posi 10 : Figure : m 2, lines grey mode : lines 1,black mode lines : for theoretical SBTW modes at 51, 47 and 42°S (Fig 300 m isobath. Colorbar units: velocity psd. Lines Frequency-Wavenumber spectrum of along-slope veloci 9:Figure deviation. standard exceeds the isobath m f) and negative g) thephase for dates when the fil alo velocity filtered along-slope of Composite f-g) This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

Φ (53.5°S), (53.5°S), Ω correspond correspond to the dispersion relation tered velocity at 100 overm the 300 ode 3, blue lines : mode 4) 4) ode: mode linesblue 3, ng the magenta section for positive positive for section magenta the ng tive tive phase of the fast waves at 47°S (47°S), and and (47°S), ng to c). tong c). ng to a). tong ure A4 in appendix).(black dashed significant values are shown. shown. are values significant velocity anomalies from Figure Figure from anomalies velocity ties ties at 100 m depth above the ath at t the dates of the velocity velocity the of dates the t Ψ Ω (41°S). (41°S). (47°S). (47°S). b. isobath 1500m the velocities at the velocities the velocities at c. anomaly. corresponding the indicate b) and a) on arrows The phase. negative thefor SLA e-f-g) the velocities at the velocities (in black) for year 2013 above the 1500 m isobath m m from the dates when the filtered velocity exceeds of 10-40 band-pass a-e) Lagged day filte composites 14:Figure 25± 4:a) in Figure as estimated 1velocities Phase a. 13 : Figure tentativ are series time The three filtered (blue). (green) day 10-40 filters: band-pass different with m m from the dates when the filtered velocity exceeds filte band-pass day 30-90 of composites Lagged f-j) This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article12: Figure

Lagged correlations of 80-110 day band pass filter Lagged correlations of 30-90 day band-pass filtered band-pass day 30-90 of correlations Lagged filtered band-pass day 10-40 of correlations Lagged GLORYS12 Along slope velocity anomalies (a) and and (a) anomalies velocity slope Along GLORYS12 Ω Ω Ω (47°S), y axis is lag in days, x axis is distance (47°S), y axis is lag in days, x axis is distance x axis is ydays, in axis lagis (47°S), (47°S), y axis is lag in days, x axis is distance x axis is ydays, in axis lagis (47°S), ely summed (grey curve). curve). (grey ely summed at the standard deviation at the standard deviation at cm/s b) 20± b) cm/s 14± c) cm/s 1 1 cm/s , 30-90 day (red) and 80-110 day day 80-110 and (red) day 30-90 , red along-slope velocities at 100 100 at velocities along-slope red red along-slope velocities at velocities along-slope red 100 Ω (47°S) and filtered time series composite of the wind stress stress wind the of composite ed along-slope velocities with along-slope velocities with velocities along-slope with velocities along-slope along along the slope above along the slope slope along the along the slope slope along the SLA (b) time series series time (b) SLA Ω Ω (47°S). (47°S). Figure A1:Figure modes Theoretical :ANNEXE filtere pass band day 13m. inused Figure dates selected to corresponding 80-110 of composites 0 Lag c) filtered pass band day 30-90 13h.inused Figure dates selected to corresponding of composites 0 Lag b) inused Fi dates selected to corresponding filtered GLORYS12 pass band day 10-40 of composites 0 Lag a) 15: Figure (47°S). 100 m from the dates when the filtered velocity exc velocity filtered the when dates the from m 100 fi band-pass day 80-110 of composites Lagged k-o) y-axi S-1, in vaisalaBrunt frequency x-axis the is each 300km for at Mean frequency Vaisala Brunt f) Burg and the is y-axis km distance in x-axis the is distance theof afunction as number Mean Burger e) km distance in x-axis the is the for velocities along-slope mean b-d) Idealized considerat 3 under sections the with Bathymetrya) This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article Set up conditions for Brink and Chapman’s model ap model Chapman’s andBrink Set for up conditions s is depth in meters meters depthin is s er number number er 3 sections (51°S, 47°S, 42°S) 47°S,42°S) (51°S, 3 sections ion. ion. eeds the standard deviation at at deviation standard the eeds

section section

along each section section along each ltered along-slope velocities at at velocities along-slope ltered gure 13c. 13c. gure sea level anomalies from from anomalies level sea d sea level anomalies anomalies level sea d sea level anomalies anomalies level sea plication: plication: Ω

42°S.Units in dyn/cmin42°S.Units secti modes1along to 4for pressure (SP) Surface A5: Figure m/s. in velocity y-axisand in km in wavelength FIGURES: a. A4 : Figure velocity. from the shelf to the open ocean and positive verti vel across-slope Positive m. 1000 upper the on Zoom S in A1). (shown and figure 42°S 47°S 51°S, section ass components velocity vertical and Across-isobath A3:Figure depth. axis Yis distance; across-slope - factor arbitrary an by normalized are velocities (1987) toolbox at 51°S, 47°S and 42°S (pink, red an co velocity along-isobath of modes gravest 4 First A2:Figure b. 4. mode to dashed lines 3 toand mode dashed lines period in days. Thick lines correspond to mode 1, t X (blue). section 42°S for and (red), section 47°S This article is protected by copyright. All rights reserved. ThisAllarticleis rights by copyright. reserved. protected Accepted Article

Dispersion curves for the first four gravest modes gravest four first the for curves Dispersion Phase velocity computed for each mode (same color c color (same mode each for computed velocity Phase

2 (1 dyn/cm (1 2 2 = = 0.1Pa). their units are consistent) X axis is is axis X consistent) are units their cal cal velocity corresponds to upwards hick lines with dots to mode 2, thick axis is wavelength in km, y-axis is is y-axis km, in wavelength is axis ons at 51°S, 47°S and 47°S 51°S, at ons d blue sections in Figure A1) (The caling as in Figure A2 A2 Figure as caling in mputed from Brink & Chapman Chapman & Brink from mputed ociated with mode and 4 along along 4 and mode with ociated ocity corresponds to velocity velocity to corresponds ocity of the 51°S section (pink), (pink), section 51°S the of ode as a). X-axis is is X-axis a). as ode Figure 1

Figure 2 2 Figure

Figure 5

Figure A3