海洋環境科技研究所(104學年度起合併至地科系)
Permanent URI for this communityhttp://rportal.lib.ntnu.edu.tw/handle/20.500.12235/64
在全球環境急遽變遷及資源耗竭下,環境議題日受重視,「環境教育」自1970年代起即成為先進國家積極推動的專業;近年來聯合國教科文組織更倡議將2005~2014訂為「永續發展教育十年」,呼籲各國積極推動環境教育及「永續發展教育」之研究與發展。國立台灣師範大學環境教育研究所為國內第一個設立的「環境教育研究所」,於民國八十二年開始招收碩士班研究生,並於民國九十五學年度起增設博士班,積極培養環境教育專業人才、推動學校及社會之環境教育與學術研究。近年則積極參與區域與地方永續發展相關研究及推廣教育,推動綠色學校、永續校園、綠色大學、自然教育中心、環境學習中心等,並與國際著名大學或研究中心合作,朝向亞太「永續教育區域專業中心」(Regional Center for Expertise on Education for Sustainable Development)發展。
本所努力方向:- 學術研究國際化,進行環境教育及永續發展創新研究,提昇學術實力;
- 深化環境教育相關理論與應用研究,培養專業人才;
- 進行環境教育教與方案之研發、應用與評估,提昇環境教育專業品質;
- 協助政府與民間進行環境教育系統規劃、政策研究與人力培訓發展,增進整體社會環境倫理與典範轉移;
- 協助政府與民間運用不同自然環境與文化資源,開創環境學習場域,提供全民多元環境學習機會,提昇國民環境素養。
依據本所98.5.22課程委員會、理學院98.5.30課程委員會及本校98.6.2.校級課程委員會三級課程委員會通過之「環境教育研究所課程架構與學生能力指標」, 本所之發展願景、教育目標及學生能力指標如下:
- 一、發展願景
- 發展成為世界第一流的環境教育研究與教學機構,引領國內環境教育之推展;
- 學術研究國際化,進行環境教育及永續發展創新研究,提昇學術研究實力;
- 環境關懷在地化,培育具有深刻環境關懷及環境教育專業能力之人才;
- 學理探討深刻化,奠立環境教育相關理論及哲學基礎,培育兼具科學基礎與環境倫理之優秀研究人才;
- 環境素養跨界化,提升科學及人文素養,培養理解自然與人文領域之整合能力,推動永續科學及永續教育之研究與社會實踐
- 二、教育發展目標
- (一)博士班教育目標:
- 培育具有精深學術素養與環境哲思基礎的環境教育學術研究人才;
- 培育國家環境教育領域之領導與創新專業人才;
- 培育兼具科學及人文素養,發展永續科學與永續教育領域之研究人才;
- 培育大專院校與人才培訓機構之環境教育相關領域研究與教學師資;
- 培育國內外環境保育、環境學習、永續產業的研究教學及專業研發人才。
- (二)碩士班教學目標:
- 培育具備環境倫理及環境素養之環境教育專業人才;
- 培育以永續發展科學為基礎的永續教育推動及管理人才;
- 培育各級學校具有學科整合能力之環境系統管理及環境教育規劃人才;
- 培養環境保護與自然保育行政部門的教育訓練規劃及整合推動之人才;
- 培養民間團體、自然教育中心、環境學習中心等領域之環境教育專業課程設計、活動企畫經營的專業人才;
- 培養協助企業社會責任、具有環境溝通與推廣能力之人才。
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Item Bimodal Behavior of the Seasonal Upwelling off the northeastern coast of Taiwan(American Geophysical Union (AGU), 2009-03-01) Chang Y.-L.; C.-R. Wu; L.-Y. OeyObservations over the outer shelf and shelf break off the northeastern coast of Taiwan indicate a curious seasonal variability of upwelling. At deeper levels 100 m below the surface, upwelling is most intense in summer but weaker in winter. Nearer the surface at approximately 30 m below the surface, the opposite is true and the upwelling is stronger in winter than in summer. Results from a high-resolution numerical model together with observations and simple Ekman models are used to explain the phenomenon. It is shown that the upwelling at deeper levels (∼100 m) is primarily induced by offshore (summer) and onshore (winter) migrations of the Kuroshio, while monsoonal change in the wind stress curl, positive in winter and negative in summer, is responsible for the reversal in the seasonal variation of the upwelling near the surface (∼30 m). This mechanism reconciles previous upwelling data.Item Blocking and westward passage of eddies in the Luzon Strait.(ELSEVIER, 2010-10-01) Sheu, W.-J.; C.-R. Wu; L.-Y. OeySatellite observations have shown the abundance of generally westward-propagating eddies in the subtropical regions in the North Pacific Ocean, especially north of 10衹. Eddies transport mass, and can significantly impact the circulation as well as the heat, salt and nutrient balances of the western Pacific marginal seas. This paper uses a numerical model to examine the conditions when eddies can or cannot freely propagate westward through the Luzon Strait into the South China Sea (SCS). Composite analyses on the 10-year model data show that the fates of eddies depend on the strength and path of the Kuroshio. In one path that exists mostly during fall and winter, the Kuroshio loops westward into the SCS, the potential vorticity (PV) across the current is weak, and eddies are likely to propagate freely through the Luzon Strait. In another path, which exists mostly during spring and summer, the Kuroshio tends to leap directly northward bypassing the SCS, the PV across it strengthens, and eddies are then blocked and are constrained to also follow the northward path. Nonlinear eddy-current interaction and the existence of a cyclone north of the Luzon Island during the looping phase explain why eddies of both signs can pass through the strait. It is shown also that the upstream state of the Kuroshio in the western tropical Pacific plays an important role in dictating the different paths of the Kuroshio. The looping (leaping) path is caused by a weakened (stronger) Kuroshio transport related to the northward (southward) shift of the North Equatorial Current in wintertime (summertime).Item Contrasting the flow patterns in the equatorial Pacific between two types of El Ni隳.(Taylor & Francis: STM, Behavioural Science and Public Health Titles, 2012-11-01) Wang, L.-C.; C.-R. WuOutputs based on the National Centers for Environmental Prediction (NCEP) Global Ocean Data Assimilation System (GODAS) are adopted to contrast the current variations in the equatorial Pacific between two types of El Niño. The model fully resolves the equatorial currents. We found that the central Pacific El Niño (CP-El Niño) corresponds well with previous El Niño studies in that both the eastward Equatorial Undercurrent (EUC) and westward South Equatorial Current (SEC) weaken. On the other hand, the eastern Pacific El Niño (EP-El Niño) displays a distinct circulation pattern. The North Equatorial Countercurrent (NECC) strengthens in the developing phase and persists into the peak of the warm event, whereas the northern branch of the SEC (SECn) also intensifies during the mature phase and lasts for about six months. The South Equatorial Countercurrent (SECC) strengthens during the decaying phase of the EP-El Niño. The shifting of the wind stress curl associated with the thermocline variability is chiefly responsible for the unique current performance of the EP-El Niño. It is worth noting that the air–sea interaction plays an important role in the current variability not only during a CP-El Niño but also during an EP-El Niño. RÉSUMÉ [Traduit par la rédaction] Nous adoptons les sorties basées sur le système GODAS (Global Ocean Data Assimilation System) des NCEP (National Centers for Environmental Prediction) pour mettre en évidence les variations de courant dans le Pacifique équatorial entre les deux types d'El Niño. Le modèle représente complètement les courants équatoriaux. Nous trouvons que l'El Niño du centre du Pacifique (CP-El Niño) correspond bien aux études précédentes sur l'El Niño puisque le sous-courant équatorial (EUC) vers l'est et le courant sud-équatorial (SEC) vers l'ouest faiblissent. D'autre part, l'El Niño de l'est du Pacifique (EP- El Niño) affiche une configuration de circulation distincte. Le contre-courant nord-équatorial (NECC) se renforce dans la phase de développement et persiste jusqu'au maximum du réchauffement, tandis que la branche nord du SEC (SECn) s'intensifie aussi durant la phase de maturité et persiste pendant environ six mois. Le contre-courant sud-équatorial se renforce durant la phase de dissipation de l'EP-El Niño. Le changement du rotationnel de la tension du vent lié à la variabilité thermocline est principalement responsable du comportement particulier du courant de l'EP-El Niño. Il est à remarquer que l'interaction air–mer joue un rôle important dans la variabilité du courant, non seulement durant un CP-El Niño mais aussi durant un EP-El Niño.Item Editorial - International Workshop on Modeling the Ocean (IWMO) special issue in Ocean Dynamics(Springer-Verlag, 2010-04-01) Oey, L.-Y.; T. Ezer, Y. Miyazawa; C.-R. WuItem Editorial - International Workshop on Modeling the Ocean (IWMO) special issue part 2 in Ocean Dynamics(Springer-Verlag, 2010-10-01) Oey, L.-Y.; T. Ezer; Y. Miyazawa; C.-R. WuItem Effects of sea level change on the upstream Kuroshio Current through the Okinawa Trough(American Geophysical Union (AGU), 2006-08-01) Kao, S. J.; C.-R. Wu; Y.-C. Hsin; M. DaiSea-level effects on the Kuroshio Current (KC) in the Okinawa Trough (OT) are examined using a 3-D ocean model. When the sea level is −135 m (for the Last Glacial Maximum), topographic high at the southernmost OT partially blocks the KC throughflow, resulting in a 43% reduction of KC inflow. Meanwhile, meandering is enhanced and deepwater ventilation is reduced. However, the KC does not migrate to the east off the OT as suggested previously. When sea level is −40 m (for the beginning of Holocene), the modeled flow pattern resembled present KC in terms of flow path and volume transport. Sea level fluctuation may act as a major control altering the KC course in the OT, leading to significant changes in horizontal and vertical water exchange. It may alter surface water properties, biogeochemistry in both water column and sediments below, potentially, downstream KC and climate over the northeast Asia.Item Enhanced primary production in the oligotrophic South China Sea by eddy injection in spring(American Geophysical Union (AGU), 2010-08-01) Lin, I-I; C.-C. Lien; C.-R. Wu; G. T. F. Wong; C.-W. Huang; T.-L. ChiangIn May 2003, a phytoplankton bloom of chlorophyll-a (Chl-a) concentration of 0.3–0.4 mgm−3 was observed at the centre of northern South China Sea (SCS) by NASA's Sea-viewing Wide Field-of-View sensor. As this region is remote and known to be oligotrophic in spring (Chl-a concentration typically at ∼0.05–0.08 mgm−3), it is intriguing to explore this unusual happening. Based on six different remote sensing data and numerical modelling, the results suggest that the injection of an ocean eddy is the most likely cause of the bloom. Due to long-range transport of a large (700 × 500 km) anti-cyclonic ocean eddy, coastal nutrients and plankton could be brought across hundreds of kilometres to the centre of northern SCS and impact the biogeochemistry. The open ocean part of the northern SCS basin has long been considered generally free from coastal influences. This work provides new evidence that proves otherwise. Moreover, from the perspective of physical oceanography, it is interesting to observe that, outside the monsoon seasons, there can be well-defined anti-cyclonic ocean circulation existing in the SCS without the prevailing monsoonal wind.Item Field Observations of Changes in SST, Chlorophyll and POC Flux in the Southern East China Sea Before and After the Passage of Typhoon Jangmi.(Chinese Geoscience Union, 2013-10-01) Shih, Y.-Y.; J.-S. Hsieh; G.-C. Gong; C.-C. Hung; W.-C. Chou; M.-A. Lee; K.-S. Chen; M.-H. Chen; C.-R. WuSevere tropical storms play an important role in triggering phytoplankton blooms, yet direct field observation of evidence of the effects of a typhoon is very rare. Sea surface temperature (SST), nitrate concentration, chlorophyll a (chl a) concentration, and particulate organic carbon (POC) flux were measured before and shortly after Typhoon Jangmi which affected the southern East China Sea (SECS) on September 28 ~ 29, 2008. In situ SST (27.5 ~ 28.0°C) on September 19 ~ 21, decreased to ~24.0°C (October 3 ~ 6) in the SECS 4 ~ 7 days after the passage of Typhoon Jangmi. In situ nitrate and chl a concentrations 7-days (on October 6) after the passage of Jangmi were 1.9 μM and 1.61 mg m-3, respectively, much higher than those (nitrate: 0.3 μM and chl a: 0.73 mg m-3) concentrations before the typhoon (September 21). The enhanced chl a concentration is thus caused by a nutrient supply via vertical mixing or upwelling in the euphotic zone. The POC flux 7-days after Jangmi’s passage was 552 ± 28 mg-C m-2 d-1, a ~2.5-fold increases before the typhoon (224 ± 33 mg-C m-2 d-1, on September 21). Our results suggest that typhoons indeed can stimulate efficient POC export out of the euphotic zone, while it is still poorly understood with regard to the total effects of a typhoon on nutrient dynamics and detailed carbon sequestration due to sampling difficulty. Therefore, successional sea-going observations ought to be conducted in the affected area after the passage of typhoons.Item Fluctuations of the thermal fronts off northeast Taiwan.(American Geophysical Union (AGU), 2011-10-01) Hsin, Y.-C.; T.-L. Chiang; C.-R. WuA high-resolution sea surface temperature (SST) data derived from several satellites is used to investigate the variability of the thermal front off northeastern Taiwan. Hidden by a dominant annual cycle, the SST data cannot reveal the thermal front fluctuation in the form of Hovm闤ler diagram. An innovative methodology has been applied to the SST satellite imagery to derive the SST Standardized Index (SSTSI), capable of revealing the frontal variability with multiple time scales. Principal component analysis shows that the SSTSI variation consists mainly of two modes. Mode 1 represents a strong annual cycle related to the seasonal reversal of the monsoonal winds. The temperature gradient is enhanced in winter and a cold dome is observed off northern Taiwan in summer. Mode 2 is highly correlated with the upstream Kuroshio variability. The shoreward (seaward) migration of the thermal front takes place when the Kuroshio transport weakens (strengthens). The results are consistent with transports estimated by tidal gauge measurements, satellite altimeter-based sea level anomaly, and surface flow patterns derived from high-frequency radars. Mode 2 is coherent with the Kuroshio transport through the East Taiwan Channel at periods of 120 and 45 d with a time lag of 40 and 11 d, respectively. This 120 d fluctuation is due to the interaction between westward-propagating eddies and the Kuroshio east of Taiwan, while the 45 d signal arises from the Kuroshio's self-instability. The interannual variations of the SST pattern in winter and summer are also discussed.Item The Interaction of Supertyphoon Maemi (2003) With a Warm Ocean Eddy(American Meteorological Society, 2005-09-01) Lin, I-I; C.-C. Wu; K. A. Emanuel; I.-H. Lee; C.-R. Wu; I.-F. PanUnderstanding the interaction of ocean eddies with tropical cyclones is critical for improving the understanding and prediction of the tropical cyclone intensity change. Here an investigation is presented of the interaction between Supertyphoon Maemi, the most intense tropical cyclone in 2003, and a warm ocean eddy in the western North Pacific. In September 2003, Maemi passed directly over a prominent (700 km 500 km) warm ocean eddy when passing over the 22°N eddy-rich zone in the northwest Pacific Ocean. Analyses of satellite altimetry and the best-track data from the Joint Typhoon Warning Center show that during the 36 h of the Maemi–eddy encounter, Maemi’s intensity (in 1-min sustained wind) shot up from 41 m s 1 to its peak of 77 m s 1. Maemi subsequently devastated the southern Korean peninsula. Based on results from the Coupled Hurricane Intensity Prediction System and satellite microwave sea surface temperature observations, it is suggested that the warm eddies act as an effective insulator between typhoons and the deeper ocean cold water. The typhoon’s self-induced sea surface temperature cooling is suppressed owing to the presence of the thicker upper-ocean mixed layer in the warm eddy, which prevents the deeper cold water from being entrained into the upper-ocean mixed layer. As simulated using the Coupled Hurricane Intensity Prediction System, the incorporation of the eddy information yields an evident improvement on Maemi’s intensity evolution, with its peak intensity increased by one category and maintained at category-5 strength for a longer period (36 h) of time. Without the presence of the warm ocean eddy, the intensification is less rapid. This study can serve as a starting point in the largely speculative and unexplored field of typhoon–warm ocean eddy interaction in the western North Pacific. Given the abundance of ocean eddies and intense typhoons in the western North Pacific, these results highlight the importance of a systematic and in-depth investigation of the interaction between typhoons and western North Pacific eddies.Item Interannual mode of sea level in the South China Sea and the roles of El Ni隳 and El Ni隳 Modoki(American Geophysical Union (AGU), 2008-02-01) Chang, C.-W. J.; H.-H. Hsu; C.-R. Wu; W.-J. SheuENSO-scale variation of the summer ocean circulation in the South China Sea (SCS) is investigated. The interannual mode of SSH features a north-south dipole pattern that modulates the cold jet off Vietnam. During the summers before and after the El Nin˜o, the mode has opposite signs of extrema. Strengthened circulations couple with the cold SSTAs during the El Nin˜o developing summers; weakened circulations accompany the warm SSTAs during the decaying summers. Heat advection by the basin circulation modulates the SST variation. The impact of the 1997 El Nin˜o on the SCS circulation contrasting that of 1994 and 2002 El Nin˜o Modoki is assessed. With moderate SST warming but further westward shift of the low-level convergence of the atmosphere in the equatorial Pacific, the El Nin˜o Modoki phenomenon enhanced the western North Pacific summer monsoon inside the SCS, driving stronger circulations in both the summers of 1994 and 2002.Item Intra-seasonal Variation of the Kuroshio southeast of Taiwan and its possible forcing mechanism(Springer-Verlag, 2010-10-01) Hsin, Y.-C.; T. Qu; C.-R. WuThe intra-seasonal variation of the Kuroshio southeast of Taiwan has been studied using satellite data and a numerical model. Superimposed with the main stream of the Kuroshio, two intra-seasonal signals are revealed in the study region. The fluctuation with a period of 1–6 months results from offshore eddies. The westward propagating cyclonic eddies can reduce or reverse the northward flow east of the Kuroshio between 121° and 123° E, but only slightly touch the core velocity of the Kuroshio. The fluctuation with a period of 2–4 weeks is only significant between Taiwan and the Lan-Yu Island (the low-velocity region). Different mechanisms are responsible for the fluctuation in the low-velocity region in different seasons. In winter, the change of negative wind stress curl in the northeastern South China Sea modulates the circulation southeast of Taiwan, while the typhoon-induced intense wind is responsible for the current fluctuation in summer.Item The Kuroshio and the East China Sea(Berlin: Springer Verlag., 2010-01-01) Liu, K.-K.; G.-C. Gong; C.-R. Wu; H.-J. LeeItem Mindanao Current/Undercurrent in an Eddy-Resolving GCM(American Geophysical Union (AGU), 2012-06-01) Qu T.; T.-L. Chiang; C.-R. Wu; P. Dutrieux; D. HuAnalysis of results from an eddy-resolving general circulation model showed two subsurface velocity cores in the mean within the depth range between 400 and 1000 m below the Mindanao Current (MC). One is confined to the inshore edge at about 126.8°E and connected with the Sulawesi Sea. The other takes place somewhat offshore around 127.7°E, being closely related to the intrusion of South Pacific water. Both cores are referred to as the Mindanao Undercurrent (MUC). The MC/MUC is approximately a geostrophic flow, except on the inshore edge of the MUC where up to 50% of the mean flow can be explained by ageostrophic dynamics. In contrast with the well-defined southward flowing MC, the MUC is of high velocity variance relative to the mean. Empirical orthogonal function (EOF) analysis shows that approximately 60% of the total velocity variance is associated with two meandering modes, with their major signatures in the subthermocline. The dominant time scale of variability is 50–100 days. An ensemble of these meso-scale fluctuations provides a northward freshwater flux on the offshore edge of the Philippine coast, which to a certain extent explains why water of South Pacific origin appears to extend farther northward than the mean MUC. In the offshore velocity core of the MUC, for example, eddy induced freshwater flux is equivalent to a mean flow of about 0.3 m s−1 in the density range between 26.9 and 27.3 kg m−3, which is greater than the mean current by a factor of 6.Item Physical and geographical origins of the South China Sea Warm Current(American Geophysical Union (AGU), 2008-08-01) Chiang T.-L.; C.-R. Wu; S.-Y. ChaoWe examine the formation mechanism of the South China Sea Warm Current in winter, using a high-resolution, numerical model. The current, noted for its ability to flow against the prevailing northeast monsoon in winter, has received considerable attentions in recent years. The collective wisdom from previous models points to two likely generation scenarios: occasional wind relaxation or the Kuroshio intrusion. The present model consistently points to the wind relaxation as the dominant mechanism. When comparing differences between previous models and ours, we also conclude that the Kuroshio intrusion helps, but is not chiefly responsible. Tracing the current to the source, we identify the elevated sea level in the Gulf of Tonkin, induced by the northeast monsoon, as the ultimate driving force. The presence of Hainan Island bears little importance in generating the current.Item Properties of Rossby Waves and Mesoscale Eddies in the South China Sea Derived from Satellite Data and a Numerical Model(2008-07-11) Sheu, W.-J.; C.-R. WuItem Seasonal to interannual variations in the intensity and central position of the surface Kuroshio east of Taiwan(American Geophysical Union (AGU), 2013-09-01) Hsin Y.-C.; B. Qiu; T.-L. Chiang; C.-R. WuSeasonal and interannual changes of surface Kuroshio intensity and central position east of Taiwan during 1993–2012 are investigated by quantitatively analyzing the satellite altimetry product. The Kuroshio moves inshore (offshore) off northeast of Taiwan in winter (summer), whereas it has an offshore (inshore) path off southeast of Taiwan in winter (summer). The seasonal change of heat flux over the East China Sea shelf is found to cause the seasonality of the Kuroshio central position off northeast of Taiwan, whereas the seasonal Kuroshio movement off southeast of Taiwan is found to be induced by the combined effect of the Kuroshio changes through the Luzon Strait and the eastern Luzon Island. In contrast to this y-dependent path changes, the Kuroshio becomes weaker (stronger) as a whole east of Taiwan in winter (summer). On the interannual time scales, the Kuroshio throughout the eastern coast of Taiwan intensifies and has a concurrent offshore path during the periods of 1995–1997 and 2004–2007. The relative intensity of cyclonic eddies to anticyclonic eddies off eastern Taiwan are found to contribute to these interannual Kuroshio changes.Item The South China Sea(Berlin: Springer Verlag., 2010-01-01) Liu, K.-K.; C.-M. Tseng; C.-R. Wu; I-I LinItem Spatial and Temporal Variations of the Kuroshio East of Taiwan, 1982-2005: A numerical study(American Geophysical Union (AGU), 2008-04-01) Hsin, Y.-C.; C.-R. Wu; P.-T. ShawA 1/8 East Asian Marginal Seas model nested to a larger-domain North Pacific Ocean model is implemented over a span of 24 years from 1982 to 2005 to investigate the spatial and temporal variations of the Kuroshio east of Taiwan. Between 22 and 25 N, the mean state and variability of the Kuroshio, such as the two paths observed in the trajectories of surface drifters southeast of Taiwan and the branching of the Kuroshio northeast of Taiwan, are well reproduced by the model. Southeast of Taiwan, the Kuroshio is mostly in the top 300 m in the inshore path but extends to 600 m in the offshore path. Northeast of Taiwan, the Kuroshio follows the shelf edge in the East China Sea but may branch along a path south of the Ryukyu Islands. The latter path often meanders southward, and a significant portion of the Kuroshio transport may be diverted to this path. The Kuroshio extends from the coast to 123–123.5 E between 22 and 25 N with currents reaching a depth of 1000 m at some latitudes. The Kuroshio transports averaged over five sections east of Taiwan are 28.4 ± 5.0 Sv and 32.7 ± 4.4 Sv with and without the contribution from the countercurrent, respectively.Item Typhoon Kai-Tak: An ocean's perfect storm(American Meteorological Society, 2011-01-01) Chiang, T.-L.; C.-R. Wu; L.-Y. OeyAn unusually intense sea surface temperature drop (ΔSST) of about 10.8°C induced by the Typhoon Kai-Tak is observed in the northern South China Sea (SCS) in July 2000. Observational and high-resolution SCS model analyses were carried out to study the favorable conditions and relevant physical processes that cause the intense surface cooling by Kai-Tak. Upwelling and entrainment induced by Kai-Tak account for 62% and 31% of the ΔSST, respectively, so that upwelling dominates vertical entrainment in producing the surface cooling for a subcritical storm such as Kai-Tak. However, wind intensity and propagation speed alone cannot account for the large ΔSST. Prior to Kai-Tak, the sea surface was anomalously warm and the main thermocline was anomalously shallow. The cause was a delayed transition of winter to summer monsoon in the northern SCS in May 2000. This produced an anomalously strong wind stress curl and a cold eddy capped by a thin layer of very warm surface water west of Luzon. Kai-Tak was the ocean’s perfect storm in passing over the eddy at the “right time,” producing the record SST drop and high chlorophyll-a concentration.