Park
Jong Jin
Park
Jong Jin
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ArticleAspiration and outflow of the intermediate water in the East/Japan Sea through the Tsugaru Strait(American Geophysical Union, 2008-04-01) Park, Jong Jin ; Kim, Kuh ; Yang, Joon-YongOutflow of the intermediate water in the East/Japan Sea through the Tsugaru Strait is inferred from the fact that profiling floats deployed below the sill depth in the central East/Japan Sea moved out to the Northwest Pacific Ocean through the Strait. Careful analysis of the float trajectories reveals that profiling floats parked at 350m, 700m, and 800m could be uplifted from depths below the sill of the Tsugaru Strait and moved over the 140m deep sill with a probability close to 100%. Application of an analytical model for the Bernoulli suction shows that intermediate waters can be aspirated over the sill depth of the Tsugaru Strait in late winter.
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ArticleThe fate of North Atlantic Subtropical Mode Water in the FLAME model(American Meteorological Society, 2014-05) Gary, Stefan F. ; Lozier, M. Susan ; Kwon, Young-Oh ; Park, Jong JinNorth Atlantic Subtropical Mode Water, also known as Eighteen Degree Water (EDW), has the potential to store heat anomalies through its seasonal cycle: the water mass is in contact with the atmosphere in winter, isolated from the surface for the rest of the year, and reexposed the following winter. Though there has been recent progress in understanding EDW formation processes, an understanding of the fate of EDW following formation remains nascent. Here, particles are launched within the EDW of an eddy-resolving model, and their fate is tracked as they move away from the formation region. Particles in EDW have an average residence time of ~10 months, they follow the large-scale circulation around the subtropical gyre, and stratification is the dominant criteria governing the exit of particles from EDW. After sinking into the layers beneath EDW, particles are eventually exported to the subpolar gyre. The spreading of particles is consistent with the large-scale potential vorticity field, and there are signs of a possible eddy-driven mean flow in the southern portion of the EDW domain. The authors also show that property anomalies along particle trajectories have an average integral time scale of ~3 months for particles that are in EDW and ~2 months for particles out of EDW. Finally, it is shown that the EDW turnover time for the model in an Eulerian frame (~3 yr) is consistent with the turnover time computed from the Lagrangian particles provided that the effects of exchange between EDW and the surrounding waters are included.
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ArticleObservation of near-inertial wave reflections within the thermostad layer of an anticyclonic mesoscale eddy(American Geophysical Union, 2010-01-15) Byun, Sang-Shin ; Park, Jong Jin ; Chang, Kyung-Il ; Schmitt, Raymond W.Moored current observations in the southwestern East/Japan Sea of 16.5 months duration clearly captured two episodes of downward phase propagation (upward energy propagation) of near-inertial waves (NIWs). Time series of temperature and velocity from the mooring and ancillary information indicate that the mooring was located near the center of an anticyclonic eddy during these events. Considering the typical vertical structure of quasi-permanent eddy features in the region, the observed downward phase propagation appeared to occur within the seasonal thermocline and upper thermostad of the anticyclonic mesoscale eddy. Ray tracing simulation of NIW using the observed subinertial currents suggests that the upward energy propagation is caused by the reflection of the NIWs within the thermostad of the anticyclonic eddy, where the effect of the vertical shear of subinertial horizontal currents is larger than the buoyancy effect in controlling the propagation of NIWs.
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PreprintComparison between a reanalyzed product by 3-dimensional variational assimilation technique and observations in the Ulleung Basin of the East/Japan Sea( 2009-04-30) Kim, Young Ho ; Chang, Kyung-Il ; Park, Jong Jin ; Park, Seon Ki ; Lee, Sang-Hyun ; Kim, Young-Gyu ; Jung, Kyung Tae ; Kim, KuhReanalyzed products from a MOM3-based East Sea Regional Ocean Model with a 3- dimentional variational data assimilation module (DA-ESROM), have been compared with the observed hydrographic and current datasets in the Ulleung Basin (UB) of the East/Japan Sea (EJS). Satellite-borne sea surface temperature and sea surface height data, and in-situ temperature profiles have been assimilated into the DA-ESROM. The performance of the DA-ESROM appears to be efficient enough to be used in an operational ocean forecast system. Comparing with the results from Mitchell et al. (2005a), the DA-ESROM fairly well simulates the high variability of the Ulleung Warm Eddy and Dok Cold Eddy as well as the branching of the Tsushima Warm Current in the UB. The overall root-mean-square error between 100m temperature field reproduced by the DA-ESROM and the observed 100-dbar temperature field is 2.1°C, and the spatially averaged grid-to-grid correlation between the two temperature fields is high with a mean value of 0.79 for the intercomparison period. The DA-ESROM reproduces the development of strong southward North Korean Cold Current (NKCC) in summer consistent with the observational results, which is thought to be an improvement of the previous numerical models in the EJS. The reanalyzed products show that the NKCC is about 35 km wide, and flows southward along the Korean coast from spring to summer with maximum monthly mean volume transport of about 0.8 Sv in August-September.
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ArticleGlobal distribution of the decay timescale of mixed layer inertial motions observed by satellite-tracked drifters(American Geophysical Union, 2009-11-05) Park, Jong Jin ; Kim, Kuh ; Schmitt, Raymond W.The decay timescale of mixed layer inertial amplitudes has been estimated from satellite tracked drifter trajectories from 1990 to 2004 as the e-folding timescale of the temporal correlation functions. The decay timescales increase with latitude in all basins except the North Atlantic. A beta dispersion model shows that dephasing leads to meridional variations of the decay timescale in the North Pacific and the Southern Ocean, but meridional variations of the buoyancy structure in the North Atlantic act to compensate the beta effect, leading to a lack of meridional variation of the decay timescale in that ocean.
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ArticleDecadal variability of the upper ocean heat content in the East/Japan Sea and its possible relationship to northwestern Pacific variability(American Geophysical Union, 2012-02-09) Na, Hanna ; Kim, Kwang-Yul ; Chang, Kyung-Il ; Park, Jong Jin ; Kim, Kuh ; Minobe, ShoshiroThe upper ocean heat content variability in the East/Japan Sea was investigated using a 40 year temperature and salinity data set from 1968 to 2007. Decadal variability was identified as the dominant mode of variability in the upper ocean (0–300 m) aside from the seasonal cycle. The decadal variability is strong to the west of northern Honshu, west of the Tsugaru Strait, and west of southern Hokkaido. Temperature anomalies at 50–125 m exhibit a large contribution to the decadal variability, particularly in the eastern part of the East/Japan Sea. The vertical structure of regressed temperature anomalies and the spatial patterns of regressed 10°C isotherms in the East/Japan Sea suggest that the decadal variability is related to upper ocean circulation in the East/Japan Sea. The decadal variability also exhibits an increasing trend, which indicates that the regions showing large decadal variations experienced warming on decadal time scales. Further analysis shows that the decadal variability in the East/Japan Sea is not locally isolated but is related to variability in the northwestern Pacific.
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ArticleYear-to-year reoutcropping of Eighteen Degree Water in an eddy-resolving ocean simulation(American Meteorological Society, 2015-04) Kwon, Young-Oh ; Park, Jong Jin ; Gary, Stefan F. ; Lozier, M. SusanWinter outcropping of the Eighteen Degree Water (EDW) and its subsequent dispersion are studied using a ° eddy-resolving simulation of the Family of Linked Atlantic Modeling Experiments (FLAME). Outcropped EDW columns in the model simulations are detected in each winter from 1990 to 1999, and particles are deployed in the center of each outcropped EDW column. Subsequently, the trajectories of these particles are calculated for the following 5 yr. The particles slowly spread away from the outcropping region into the nonoutcropping/subducted EDW region south of ~30°N and eventually to the non-EDW region in the greater subtropical gyre. Approximately 30% of the particles are found in non-EDW waters 1 yr after deployment; after 5 yr, only 25% of the particles are found within EDW. The reoutcropping time is defined as the number of years between when a particle is originally deployed in an outcropping EDW column and when that particle is next found in an outcropping EDW column. Of the particles, 66% are found to reoutcrop as EDW in 1 yr, and less than 5% of the particles outcrop in each of the subsequent 4 yr. While the individual trajectories exhibit significant eddy-like motions, the time scale of reoutcropping is primarily set by the mean circulation. The dominance of reoutcropping in 1 yr suggests that EDW outcropping contributes considerably to the persistence of surface temperature anomalies from one winter to the next, that is, the reemergence of winter sea surface temperature anomalies.
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ArticleArgo array observation of ocean heat content changes induced by tropical cyclones in the north Pacific(American Geophysical Union, 2011-12-16) Park, Jong Jin ; Kwon, Young-Oh ; Price, James F.In situ observations from the autonomous Argo float array are used to assess the basin-averaged ocean heat content change driven by tropical cyclones (TCs) in the North Pacific for 2000–2008. A new statistical approach based on pairs of profiles before and after each TC event is employed here to estimate the near-surface and subsurface heat content changes. Previous studies have suggested a dominant role for vertical mixing in the SST cooling response during TC passages. The Argo float observations show that, under strong TCs (greater than or equal to category 4), the subsurface warming expected from vertical mixing occurs with comparable magnitude to near-surface cooling. However, when weak TCs (less than or equal to category 3, which are about 86% of the total of TCs) were also considered, the subsurface warming was not detectable in the Argo data set, while near-surface cooling was still significant. Therefore, these results suggest that air-sea heat exchange and (upward) vertical advection likely play a somewhat greater role in the case of weak TCs. Additionally, Argo observations suggest that the restoring time scale of the near-surface heat content is greater than 30 days, which may be compared with the approximately 10 day time scale for the restoration of sea surface temperature. The mixed layer temperature and mixed layer depth evolutions also estimated from Argo data support the notion that only a thin surface layer is restored quickly to pre-TC conditions, while the rest of the cooled near-surface layer retained the TC-induced response for a good deal longer.
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ArticleOn the effect of the East/Japan Sea SST variability on the North Pacific atmospheric circulation in a regional climate model(John Wiley & Sons, 2014-01-27) Seo, Hyodae ; Kwon, Young-Oh ; Park, Jong JinThe East/Japan Sea (EJS) is a semi-enclosed marginal sea located in the upstream of the North Pacific storm track, where the leading modes of wintertime interannual variability in sea surface temperature (SST) are characterized by the basin-wide warming-cooling and the northeast-southwest dipole. Processes leading to local and remote atmospheric responses to these SST anomalies are investigated using the Weather Research and Forecast (WRF) model. The atmosphere in direct contact with anomalous diabatic forcing exhibits a linear and symmetric response with respect to the sign, pattern, and magnitude of SST anomalies, producing increased (decreased) wind speed and precipitation response over warm (cold) SSTs. This local response is due to modulation of both the vertical stability of the marine atmospheric boundary layer and the adjustment of sea level pressure, although the latter provides a better explanation of the quadrature relationship between SST and wind speed. The linearity in the local response suggests the importance of fine-scale EJS SSTs to predictability of the regional weather and climate variability. The remote circulation response, in contrast, is strongly nonlinear. An intraseasonal equivalent barotropic ridge emerges in the Gulf of Alaska as a common remote response independent of EJS SST anomalies. This downstream blocking response is reinforced by the enhanced storm track variability east of Japan via transient eddy vorticity flux convergence. Strong nonlinearity in remote response implies that detailed EJS SST patterns may not be critical to this downstream ridge response. Overall, results demonstrate a remarkably far-reaching impact of the EJS SSTs on the atmospheric circulation.
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ArticleTemporal and spatial variability of particle transport in the deep Arctic Canada Basin(John Wiley & Sons, 2015-04-11) Hwang, Jeomshik ; Kim, Minkyoung ; Manganini, Steven J. ; McIntyre, Cameron P. ; Haghipour, Negar ; Park, Jong Jin ; Krishfield, Richard A. ; Macdonald, Robie W. ; McLaughlin, Fiona A. ; Eglinton, Timothy I.To better understand the current carbon cycle and potentially detect its change in the rapidly changing Arctic Ocean, we examined sinking particles collected quasi-continuously over a period of 7 years (2004–2011) by bottom-tethered sediment trap moorings in the central Canada Basin. Total mass flux was very low (<100 mg m−2 d−1) at all sites and was temporally decoupled from the cycle of primary production in surface waters. Extremely low radiocarbon contents of particulate organic carbon and high aluminum contents in sinking particles reveal high contributions of resuspended sediment to total sinking particle flux in the deep Canada Basin. Station A (75°N, 150°W) in the southwest quadrant of the Canada Basin is most strongly influenced while Station C (77°N, 140°W) in the northeast quadrant is least influenced by lateral particle supply based on radiocarbon content and Al concentration. The results at Station A, where three sediment traps were deployed at different depths, imply that the most likely mode of lateral particle transport was as thick clouds of enhanced particle concentration extending well above the seafloor. At present, only 1%–2% of the low levels of new production in Canada Basin surface waters reaches the interior basin. Lateral POC supply therefore appears to be the major source of organic matter to the interior basin. However, ongoing changes to surface ocean boundary conditions may influence both lateral and vertical supply of particulate material to the deep Canada Basin.
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ArticleOceanGliders: A component of the integrated GOOS(Frontiers Media, 2019-10-02) Testor, Pierre ; de Young, Brad ; Rudnick, Daniel L. ; Glenn, Scott ; Hayes, Daniel J. ; Lee, Craig M. ; Pattiaratchi, Charitha ; Hill, Katherine Louise ; Heslop, Emma ; Turpin, Victor ; Alenius, Pekka ; Barrera, Carlos ; Barth, John A. ; Beaird, Nicholas ; Bécu, Guislain ; Bosse, Anthony ; Bourrin, François ; Brearley, J. Alexander ; Chao, Yi ; Chen, Sue ; Chiggiato, Jacopo ; Coppola, Laurent ; Crout, Richard ; Cummings, James A. ; Curry, Beth ; Curry, Ruth G. ; Davis, Richard F. ; Desai, Kruti ; DiMarco, Steven F. ; Edwards, Catherine ; Fielding, Sophie ; Fer, Ilker ; Frajka-Williams, Eleanor ; Gildor, Hezi ; Goni, Gustavo J. ; Gutierrez, Dimitri ; Haugan, Peter M. ; Hebert, David ; Heiderich, Joleen ; Henson, Stephanie A. ; Heywood, Karen J. ; Hogan, Patrick ; Houpert, Loïc ; Huh, Sik ; Inall, Mark E. ; Ishii, Masao ; Ito, Shin-ichi ; Itoh, Sachihiko ; Jan, Sen ; Kaiser, Jan ; Karstensen, Johannes ; Kirkpatrick, Barbara ; Klymak, Jody M. ; Kohut, Josh ; Krahmann, Gerd ; Krug, Marjolaine ; McClatchie, Sam ; Marin, Frédéric ; Mauri, Elena ; Mehra, Avichal ; Meredith, Michael P. ; Meunier, Thomas ; Miles, Travis ; Morell, Julio M. ; Mortier, Laurent ; Nicholson, Sarah ; O'Callaghan, Joanne ; O'Conchubhair, Diarmuid ; Oke, Peter ; Pallás-Sanz, Enric ; Palmer, Matthew D. ; Park, Jong Jin ; Perivoliotis, Leonidas ; Poulain, Pierre Marie ; Perry, Ruth ; Queste, Bastien ; Rainville, Luc ; Rehm, Eric ; Roughan, Moninya ; Rome, Nicholas ; Ross, Tetjana ; Ruiz, Simon ; Saba, Grace ; Schaeffer, Amandine ; Schönau, Martha ; Schroeder, Katrin ; Shimizu, Yugo ; Sloyan, Bernadette M. ; Smeed, David A. ; Snowden, Derrick ; Song, Yumi ; Swart, Sebastiaan ; Tenreiro, Miguel ; Thompson, Andrew ; Tintoré, Joaquín ; Todd, Robert E. ; Toro, Cesar ; Venables, Hugh J. ; Wagawa, Taku ; Waterman, Stephanie N. ; Watlington, Roy A. ; Wilson, DougThe OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the world: (1) to observe the long-term physical, biogeochemical, and biological ocean processes and phenomena that are relevant for societal applications; and, (2) to contribute to the GOOS through real-time and delayed mode data dissemination. The OceanGliders program is distributed across national and regional observing systems and significantly contributes to integrated, multi-scale and multi-platform sampling strategies. OceanGliders shares best practices, requirements, and scientific knowledge needed for glider operations, data collection and analysis. It also monitors global glider activity and supports the dissemination of glider data through regional and global databases, in real-time and delayed modes, facilitating data access to the wider community. OceanGliders currently supports national, regional and global initiatives to maintain and expand the capabilities and application of gliders to meet key global challenges such as improved measurement of ocean boundary currents, water transformation and storm forecast.