Three‐compartment structure of subsurface‐intensified mesoscale eddies in the ocean

Zhang, Zhengguang; Zhang, Yu; Wang, Wei

doi:10.1002/2016jc012376

Cited by 46 publications

(64 citation statements)

References 54 publications

(72 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values are blanked above the mixed layer to remove the spikes. It can be seen that the water volume trapped by the SAE exhibits a vertical three-compartment structure if only considering the effect of PV f (Figure 10a) which is consistent to the result of Zhang et al [26]. The low potential vorticity is located in the middle layer, while the high potential vorticity waters are located in the upper and deep layers.…”

Section: Discussionsupporting

confidence: 80%

“…In a recent study, Zhang et al [26] found that the volume of the water trapped by the SAE has a three-compartment structure in the vertical with the mode water being located in the middle (Figure 6). However, they ignored the effects of relative vorticity and thought it is not important.…”

Section: Discussionmentioning

confidence: 99%

“…It was characterized as the Mediterranean Water from the eastern Atlantic [18].Subsurface eddy were also observed in other regions, such as the Japan Sea [19], the southwestern South China Sea [20], the Bay of Bengal [21], the southeastern Baltic Sea [22], the southern Indian Ocean [23], the Sargasso Sea [24], Gulf of Mexico [25]. Recently, 1073 SAEs were detected in the global ocean based on available Argo profiles by [26]. Most of these SAEs are located near the regions of mode water formation and strong subsurface currents in the subtropical area.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Observations of an Extra-Large Subsurface Anticyclonic Eddy in the Northwestern Pacific Subtropical Gyre

Nan¹,

Yu²,

Wei³

et al. 2017

J Marine Sci Res Dev

View full text Add to dashboard Cite

An extra-large subsurface anticyclonic eddy (SAE) with horizontal scale of 470 km was detected in the northwestern Pacific subtropical gyre by in situ measurements in October 2014. The SAE exhibited a lens-shaped vertical structure with shoaling of the seasonal thermocline and deepening of the main thermocline. Consequently, the water in the eddy core was colder above 200 m and warmer below 200 m than the surrounding waters with maximum temperature anomalies of -1.2°C and 3.5°C located at ~100 m and ~450 m depths, respectively. The central water mass of the SAE was characterized as low potential vorticity water, i.e., the north Pacific Subtropical Mode Water (STMW). Swirl velocity of the SAE was directly observed by ship-mounted ADCP (Acoustic Doppler Current Profilers). The maximum azimuthal velocity reached 0.35 ms -1 near a 110 km radius at ~ 200 m depth, which was comparable with the maximum velocity of the northward Kuroshio east of Taiwan at the same depth. Threedimensional structure and evolutionary process of the SAE were also presented using Argo float profile data as well as the satellite altimeter data. The results indicated that the SAE was generated in the region of the STMW in February, then propagated westward over 1500 km at a mean speed of ~0.06 ms -1 and finally disappeared east of Taiwan in December, transporting ~0.5 Sv (Sv=10 6 m 3 s -1 ) STMW..

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Observations of an Extra-Large Subsurface Anticyclonic Eddy in the Northwestern Pacific Subtropical Gyre

Nan¹,

Yu²,

Wei³

et al. 2017

J Marine Sci Res Dev

View full text Add to dashboard Cite

show abstract

“…An anticyclonic mode water eddy observed at the Stratus mooring in February/March 2012 indicated high primary production just below the mixed layer (Stramma et al, 2014). According to a global investigation the eastern South Pacific off Peru and Chile seems to have the highest amount of MWEs, which are also deep reaching compared to other regions (Zhang et al, 2017). Nevertheless, in the mooring deployment 15 period 2014/2015 only one MWE crossed to the north of the mooring and the results have to be regarded with caution.…”

Section: Discussionmentioning

confidence: 99%

Impact of mesoscale eddies on water mass and oxygen distribution in the eastern tropical South Pacific

Czeschel

Schütte

Weller

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…They estimated that about 9 % of all eddies (20 % of all anticyclonic-rotating eddies) in the eastern tropical North Atlantic are ACMEs. Zhang et al (2017) found modewater eddies in all ocean basins and primarily in the upper 1000 m.…”

Section: Introductionmentioning

confidence: 99%

Upwelling and isolation in oxygen-depleted anticyclonic modewater eddies and implications for nitrate cycling

et al. 2017

View full text Add to dashboard Cite

Abstract. The temporal evolution of the physical and biogeochemical structure of an oxygen-depleted anticyclonic modewater eddy is investigated over a 2-month period using high-resolution glider and ship data. A weakly stratified eddy core (squared buoyancy frequency N 2 ∼ 0.1 × 10 −4 s −2 ) at shallow depth is identified with a horizontal extent of about 70 km and bounded by maxima in N 2 . The upper N 2 maximum (3-5 × 10 −4 s −2 ) coincides with the mixed layer base and the lower N 2 maximum (0.4 × 10 −4 s −2 ) is found at about 200 m depth in the eddy centre. The eddy core shows a constant slope in temperature/salinity (T /S) characteristic over the 2 months, but an erosion of the core progressively narrows down the T /S range. The eddy minimal oxygen concentrations decreased by about 5 µmol kg −1 in 2 months, confirming earlier estimates of oxygen consumption rates in these eddies.Separating the mesoscale and perturbation flow components reveals oscillating velocity finestructure (∼ 0.1 m s −1 ) underneath the eddy and at its flanks. The velocity finestructure is organized in layers that align with layers in properties (salinity, temperature) but mostly cross through surfaces of constant density. The largest magnitude in velocity finestructure is seen between the surface and 140 m just outside the maximum mesoscale flow but also in a layer underneath the eddy centre, between 250 and 450 m. For both regions a cyclonic rotation of the velocity finestructure with depth suggests the vertical propagation of near-inertial wave (NIW) energy. Modification of the planetary vorticity by anticyclonic (eddy core) and cyclonic (eddy periphery) relative vorticity is most likely impacting the NIW energy propagation. Below the low oxygen core salt-finger type double diffusive layers are found that align with the velocity finestructure.Apparent oxygen utilization (AOU) versus dissolved inorganic nitrate (NO − 3 ) ratios are about twice as high (16) in the eddy core compared to surrounding waters (8.1). A large NO − 3 deficit of 4 to 6 µmol kg −1 is determined, rendering denitrification an unlikely explanation. Here it is hypothesized that the differences in local recycling of nitrogen and oxygen, as a result of the eddy dynamics, cause the shift in the AOU : NO − 3 ratio. High NO − 3 and low oxygen waters are eroded by mixing from the eddy core and entrain into the mixed layer. The nitrogen is reintroduced into the core by gravitational settling of particulate matter out of the euphotic zone. The low oxygen water equilibrates in the mixed layer by air-sea gas exchange and does not participate in the gravitational sinking. Finally we propose a mesoscalesubmesoscale interaction concept where wind energy, mediated via NIWs, drives nutrient supply to the euphotic zone and drives extraordinary blooms in anticyclonic mode-water eddies.

show abstract

Three‐compartment structure of subsurface‐intensified mesoscale eddies in the ocean

Cited by 46 publications

References 54 publications

Observations of an Extra-Large Subsurface Anticyclonic Eddy in the Northwestern Pacific Subtropical Gyre

Observations of an Extra-Large Subsurface Anticyclonic Eddy in the Northwestern Pacific Subtropical Gyre

Impact of mesoscale eddies on water mass and oxygen distribution in the eastern tropical South Pacific

Upwelling and isolation in oxygen-depleted anticyclonic modewater eddies and implications for nitrate cycling

Contact Info

Product

Resources

About