Fig. 1. The locations of CTD observation stations provided by NIFS (National Institute of Fisheries Science). Black rectangle indicates the region of interest for the Ulleung Warm Eddy.
Fig. 2. Grid points for the correction of the CMEMS data (▲: tidal station, □ and ○: grid points to be calibrated).
Fig. 3. Distributions of sea level anomaly (SLA). (A) Before and (B) after the correction.
Fig. 4. The ocean current map and study area of the East Sea. Black rectangle indicates the region of interest for the Ulleung Warm Eddy (modified from Park et al., 2013).
Fig. 5. Search process of the Ulleung Warm Eddy (UWE) using the sea level anomaly (black curve) data in in July 4th, 2011. (A) The black dots indicate the minimum flow velocity. (B) The red dots indicate that the V-G algorithm is satisfied. (C) The blue areas indicate the area where the Okubo-Weiss parameter (W) is less than -0.2σ. (D) Red points and the blue areas indicate the only areas where the relative vorticity is negative (warm eddies).
Fig. 6. The number of generations of the UWEs at each year from 1993 to 2017.
Fig. 7. The number of monthly (A) generations and (B) extinctions of the UWEs.
Fig. 8. The lifespan of the UWEs.
Fig. 9. Four types of the UWE pattern according to distributions of the East Korean Warm Current (EKWC). (A) Type I (enclosed pattern by the EKWC), (B) Type II (coupled pattern by the EKWC), (C) Type III (warm streamer pattern) and (D) Type IV (independent pattern). The black and white arrows represent the mainstream of the EKWC (or the Tshshima Warm Current) and the UWE, respectively. The current vector shows the velocity field computed from the SSH during 1993-2017.
Fig. 10. Seasonal changes of the UWE ’s temperature (upper pannel) and salinity (lower pannel) vertical structure formed in January 2007.
Fig. 11. Seasonal changes of the UWE ’s temperature (upper pannel) and salinity (lower pannel) vertical structure in 2015.
Fig. 12. SSH contour (red) representing the EKWC and the UWE in February 26th, 2013. The concentric circular closed curve of the SSH contour indicates the UWE, the black arrows along the line 104 through the center of the UWE in the vicinity of 37 ° N are the geostrophic velocity vectors. The light blue region shows the area with the Okubo-Weiss parameter W <0 (eddy range).
Fig. 13. Comparison of the size of the UWE calculated from SSH (A) and temperature vertical section (B and D) at line 104 in February 2013. (A and B) The blue line shows the Okubo-Weiss method (O-W), the red solid line shows the Winding Angle method (W-A), and the green solid line shows the geostrophic velocity method of Vector Geometry algorithm (velocity). (C and D) Methods to estimate the UWE size by using the isotherm of the thermocline (CTD), 10℃ isotherm at 100m depth (100m 1 0℃) and outermost isotherm at 200m depth (200m T) in water temperature vertical section are shown.
Fig. 14. The average size of the UWEs calculated by maximum velocity method in (A) the east-west direction and (B) the north-south direction.
Fig. 15. The average size of the UWEs calculated by O-W method in (A) the east-west direction and (B) the north-south direction.
Fig. 16. Size changes in the east-west direction and the north-south direction of the UWE generated in July 2014.
Fig. 17. Schematics of three UWE patterns according to distributions of the EKWC. (A) Coupled pattern, (B) warm streamer pattern, (C) independent pattern. The black arrows indicate the mainstream of the EKWC and Tshshima Warm Current, and the red arrow represents the UWE.
Fig. 18. Ulleung Warm Eddy patters. (A) Coupled (W1) and Warm Streamer (W2) patterns in May 21th, 2010, and (B) Coupled (W3) and Independent (W4) patterns in July 25th, 2011.
Fig. 19. Schematic illustration of seasonal change of the UWE’s temperature (T) and salinity (S) vertical structure.
Table 1. The average size of the UWEs calculated from altimetric data (SSH) and vertical section of water temperature by type
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피인용 문헌
- Influence of Sediment Resuspension on the Biological Pump of the Southwestern East Sea (Japan Sea) vol.8, 2019, https://doi.org/10.3389/feart.2020.00144