The Identification and Prediction of Mesoscale Eddy Variation via Memory in Memory With Scheduled Sampling for Sea Level Anomaly

Ocean mesoscale eddies are ubiquitous in world ocean and account for 90% oceanic kinetic energy, which dominate the upper ocean flow field. Accurately predicting the variation of ocean mesoscale eddies is the key to understand the oceanic flow field and circulation system. In this article, we propose to make an initial attempt to explore spatio-temporal predictability of mesoscale eddies, employing deep learning architecture, which primarily establishes Memory In Memory (MIM) for sea level anomaly (SLA) prediction, combined with the existing mesoscale eddy detection. Oriented to the western Pacific ocean (125°−137.5°E and 15°−27.5°N), we quantitatively investigate the historic daily SLA variability at a 0.25° spatial resolution from 2000 to 2018, derived by satellite altimetry. We develop the enhanced MIM prediction strategies, equipped with Gated Recurrent Unit (GRU) and spatial attention module, in a scheduled sampling manner, which overcomes the gradient vanishing and complements to strengthen spatio-temporal features for long-term dependencies. At the early stage, the real value SLA input guides the model training process for initialization, while the scheduled sampling intentionally feeds the newly predicted value, to resolve the distribution inconsistency of inference. It has been demonstrated in our experiment results that our proposed prediction scheme outperformed the state-of-art approaches for SLA time series, with MAPE, RMSE of the 14-day prediction duration, respectively, 5.1%, 0.023 m on average, even up to 4.6%, 0.018 m for the effective sub-regions, compared to 19.8%, 0.086 m in ConvLSTM and 8.3%, 0.040 m in original MIM, which greatly facilitated the mesoscale eddy prediction. This proposed scheme will be beneficial to understand of the underlying dynamical mechanism behind the predictability of mesoscale eddies in the future, and help the deployment of ARGO, glider, AUV and other observational platforms.

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Technical Note: Watershed strategy for oceanic mesoscale eddy splitting

Ocean Science Discussions ◽

10.5194/osd-11-1719-2014 ◽

2014 ◽

Vol 11 (3) ◽

pp. 1719-1732

Author(s):

Q. Y. Li ◽

L. Sun

Keyword(s):

Splitting Method ◽

Mesoscale Eddy ◽

Mesoscale Eddies ◽

Technical Note ◽

Automatic Identification ◽

Physical Parameters ◽

Splitting Algorithm ◽

Sea Level Anomaly ◽

Simply Connected ◽

General Method

Abstract. To identify oceanic mononuclear mesoscale eddies, a threshold-free splitting method was developed based on the watershed. Because oceanic eddies are similar to plateaus and basins in the map of the sea level anomaly (SLA) data, the natural divisions of the basins are the watersheds between them. The splitting algorithm is based on identifying these watersheds by finding the path of steepest descent. Compared to previous splitting methods, the proposed splitting algorithm has some advantages. First, there are no artificial parameters. Second, the algorithm is robust; the splitting strategy is independent of the algorithm and procedure and automatically guarantees that the split mononuclear eddies are simply-connected pixel sets. Third, the new method is very fast, and the time complexity is O(N), where N is the number of multinuclear eddy pixels; each pixel is scanned only once for splitting, regardless of how many extremes there are. Fourth, the algorithm is independent of parameters; the strategy can potentially be applied to any possible physical parameters (e.g., SLA, geostrophic potential vorticity, Okubo–Weiss parameter, etc.). Besides, the present strategy can also be applied to automatic identification of troughs and ridges from weather charts. Because this general method can be applied to a variety of eddy parameter fields, we denoted it the Universal Splitting Technology for Circulations (USTC) method.

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Technical Note: Watershed strategy for oceanic mesoscale eddy splitting

Ocean Science ◽

10.5194/os-11-269-2015 ◽

2015 ◽

Vol 11 (2) ◽

pp. 269-273 ◽

Cited By ~ 10

Author(s):

Q. Y. Li ◽

L. Sun

Keyword(s):

Splitting Method ◽

Mesoscale Eddy ◽

Mesoscale Eddies ◽

Technical Note ◽

Automatic Identification ◽

Physical Parameters ◽

Splitting Algorithm ◽

Sea Level Anomaly ◽

Simply Connected ◽

General Method

Abstract. To identify oceanic mononuclear mesoscale eddies, a threshold-free splitting method was developed based on the watershed. Because oceanic eddies are similar to plateaus and basins in the map of the sea level anomaly (SLA) data, the natural divisions of the basins are the watersheds between them. The splitting algorithm is based on identifying these watersheds by finding the path of steepest descent. Compared to previous splitting methods, the proposed splitting algorithm has some advantages. First, there are no artificial parameters. Second, the algorithm is robust; the splitting strategy is independent of the algorithm and procedure and automatically guarantees that the split mononuclear eddies are simply connected pixel sets. Third, the new method is very fast, and the time complexity is O(N), where N is the number of multinuclear eddy pixels; each pixel is scanned only once for splitting, regardless of how many extremes there are. Fourth, the algorithm is independent of parameters; the strategy can potentially be applied to any possible physical parameters (e.g. SLA, geostrophic potential vorticity, Okubo–Weiss parameter). Besides, the present strategy can also be applied to automatic identification of troughs and ridges from weather charts. Because this general method can be applied to a variety of eddy parameter fields, we denoted it the Universal Splitting Technology for Circulations (USTC) method.

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SPATIO-TEMPORAL CHARACTERISTICS OF SEA LEVEL ANOMALY IN THE INDONESIAN WATER

GEOMATIKA ◽

10.24895/jig.2019.25-2.980 ◽

2019 ◽

Vol 25 (2) ◽

pp. 103

Author(s):

Dina Anggreni Sarsito ◽

Dudy Darmawan Wijaya ◽

Nur Fajar Trihantoro ◽

Muhammad Syahrullah Fathulhuda ◽

Dhota Pradipta

Keyword(s):

Sea Level ◽

Geographical Location ◽

Sea Surface Height ◽

Sea Surface ◽

Sea Level Anomaly ◽

Level Data ◽

Mean Sea Surface ◽

Spatio Temporal ◽

East Asia Region ◽

The Impact

<p>Indonesia is an archipelago state lies between Indian and Pacific Oceans at the South East Asia region. Its unique geomorphological and geographical setting affect variabilities of instantaneous sea surface height (ISSH) concering to one of the sea reference surface i.e mean sea surface height (MSSH). The differences between both heights, known as sea level anomaly (SLA), can be recognized as one of the parameter that describes the dynamic phenomena of the ocean. We investigated the Spatiotemporal characteristics of long-term SLA in this research based on 30 years of sea-level data derived from the multi-mission of satellite Altimetry (Topex/Poseidon, Jason-1, Jason-2 and Jason-3). The Spatiotemporal of SLA characteristics in Indonesian waters indicate substantial variations due to the influences of geographical location, bathymetric depth, and seasonal patterns. The SLA rate in the Indonesian region provides values that vary between 3.4 mm/yr to 5.3 mm/yr that higher than 3.2 mm/yr global SLA rate. The impact caused by the phenomenon needs to be taken into account given the vulnerability and disaster that could endanger the islands and coastal area in Indonesia. <strong></strong></p>

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Detection and tracking of mesoscale eddies in the Mediterranean Sea: A comparison between the Sea Level Anomaly and the Absolute Dynamic Topography fields

Advances in Space Research ◽

10.1016/j.asr.2020.03.039 ◽

2020 ◽

Author(s):

Cori Pegliasco ◽

Alexis Chaigneau ◽

Rosemary Morrow ◽

Franck Dumas

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Mesoscale Eddies ◽

Dynamic Topography ◽

Sea Level Anomaly ◽

Detection And Tracking ◽

The Mediterranean ◽

The Absolute

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Three-Dimensional Spatio-Temporal Disturbance Flow Field Analysis of Particulate-Induced High-Speed Boundary-Layer Transition

AIAA Scitech 2021 Forum ◽

10.2514/6.2021-1657 ◽

2021 ◽

Author(s):

Sayed Mohammad Abdullah Al Hasnine ◽

Vincenzo Russo ◽

Anatoli Tumin ◽

Christoph Brehm

Keyword(s):

Boundary Layer ◽

Flow Field ◽

High Speed ◽

Three Dimensional ◽

Boundary Layer Transition ◽

Field Analysis ◽

Layer Transition ◽

Flow Field Analysis ◽

Spatio Temporal

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ON EVALUATION OF THE ROLE OF THERMAL AND WIND FACTORS FOR A PHYSICAL MODEL OF THE WORLD OCEAN GENERAL CIRCULATION SYSTEM

Journal of Oceanological Research ◽

10.29006/1564-2291.jor-2019.47(3).7 ◽

2019 ◽

Vol 47 (3) ◽

pp. 80-91

Author(s):

V. G. Neiman

Keyword(s):

Physical Model ◽

Ocean Circulation ◽

General Circulation ◽

World Ocean ◽

Circulation System ◽

The Public ◽

The World ◽

Almost All ◽

Conceptual Foundations

The main content of the work consists of certain systematization and addition of longexisting, but eventually deformed and partly lost qualitative ideas about the role of thermal and wind factors that determine the physical mechanism of the World Ocean’s General Circulation System (OGCS). It is noted that the conceptual foundations of the theory of the OGCS in one form or another are contained in the works of many well-known hydrophysicists of the last century, but the aggregate, logically coherent description of the key factors determining the physical model of the OGCS in the public literature is not so easy to find. An attempt is made to clarify and concretize some general ideas about the two key blocks that form the basis of an adequate physical model of the system of oceanic water masses motion in a climatic scale. Attention is drawn to the fact that when analyzing the OGCS it is necessary to take into account not only immediate but also indirect effects of thermal and wind factors on the ocean surface. In conclusion, it is noted that, in the end, by the uneven flow of heat to the surface of the ocean can be explained the nature of both external and almost all internal factors, in one way or another contributing to the excitation of the general, or climatic, ocean circulation.

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Depositional setting and limiting factors of early Late Cretaceous glaucony formation: implications from Cenomanian glauconitic strata (Elbtal Group, Germany)

Facies ◽

10.1007/s10347-021-00627-y ◽

2021 ◽

Vol 67 (3) ◽

Author(s):

Markus Wilmsen ◽

Udita Bansal

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Time Scales ◽

Late Cretaceous ◽

Limiting Factors ◽

High Accumulation ◽

Spatio Temporal ◽

Facies Types ◽

Facies Succession ◽

Early Late

AbstractCenomanian strata of the Elbtal Group (Saxony, eastern Germany) reflect a major global sea-level rise and contain, in certain intervals, a green authigenic clay mineral in abundance. Based on the integrated study of five new core sections, the environmental background and spatio-temporal patterns of these glauconitic strata are reconstructed and some general preconditions allegedly needed for glaucony formation are critically questioned. XRD analyses of green grains extracted from selected samples confirm their glauconitic mineralogy. Based on field observations as well as on the careful evaluation of litho- and microfacies, 12 glauconitc facies types (GFTs), broadly reflecting a proximal–distal gradient, have been identified, containing granular and matrix glaucony of exclusively intrasequential origin. When observed in stratigraphic succession, GFT-1 to GFT-12 commonly occur superimposed in transgressive cycles starting with the glauconitic basal conglomerates, followed up-section by glauconitic sandstones, sandy glauconitites, fine-grained, bioturbated, argillaceous and/or marly glauconitic sandstones; glauconitic argillaceous marls, glauconitic marlstones, and glauconitic calcareous nodules continue the retrogradational fining-upward trend. The vertical facies succession with upwards decreasing glaucony content demonstrates that the center of production and deposition of glaucony in the Cenomanian of Saxony was the nearshore zone. This time-transgressive glaucony depocenter tracks the regional onlap patterns of the Elbtal Group, shifting southeastwards during the Cenomanian 2nd-order sea-level rise. The substantial development of glaucony in the thick (60 m) uppermost Cenomanian Pennrich Formation, reflecting a tidal, shallow-marine, nearshore siliciclastic depositional system and temporally corresponding to only ~ 400 kyr, shows that glaucony formation occurred under wet, warm-temperate conditions, high accumulation rates and on rather short-term time scales. Our new integrated data thus indicate that environmental factors such as great water depth, cool temperatures, long time scales, and sediment starvation had no impact on early Late Cretaceous glaucony formation in Saxony, suggesting that the determining factors of ancient glaucony may be fundamentally different from recent conditions and revealing certain limitations of the uniformitarian approach.

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Spatiotemporal Variability of Mesoscale Eddies in the Indonesian Seas

Remote Sensing ◽

10.3390/rs13051017 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1017

Author(s):

Zhanjiu Hao ◽

Zhenhua Xu ◽

Ming Feng ◽

Qun Li ◽

Baoshu Yin

Keyword(s):

World Ocean ◽

Mesoscale Eddies ◽

Spatial Inhomogeneity ◽

Spatiotemporal Variability ◽

Identification Algorithm ◽

Mean Flow ◽

Sulu Sea ◽

Indonesian Seas ◽

Highly Nonlinear ◽

Eddy Generation

Mesoscale eddies are ubiquitous in the world ocean and well researched both globally and regionally, while their properties and distributions across the whole Indonesian Seas are not yet fully understood. This study investigates for the first time the spatiotemporal variations and generation mechanisms of mesoscale eddies across the whole Indonesian Seas. Eddies are detected from altimetry sea level anomalies by an automatic identification algorithm. The Sulu Sea, Sulawesi Sea, Maluku Sea and Banda Sea are the main eddy generation regions. More than 80% of eddies are short-lived with a lifetime below 30 days. The properties of eddies exhibit high spatial inhomogeneity, with the typical amplitudes and radiuses of 2–6 cm and 50–160 km, respectively. The most energetic eddies are observed in the Sulawesi Sea and Seram Sea. Eddies feature different seasonal cycles between anticyclonic and cyclonic eddies in each basin, especially given that the average latitude of the eddy centroid has inverse seasonal variations. About 48% of eddies in the Sulawesi Sea are highly nonlinear, which is the case for less than 30% in the Sulu Sea and Banda Sea. Instability analysis is performed using high-resolution model outputs from Bluelink Reanalysis to assess mechanisms of eddy generation. Barotropic instability of the mean flow dominates eddy generation in the Sulu Sea and Sulawesi Sea, while baroclinic instability is slightly more in the Maluku Sea and Banda Sea.

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Mean Sea Level as a Reference for Geodetic Leveling

The Canadian Surveyor ◽

10.1139/tcs-1974-0095 ◽

1974 ◽

Vol 28 (5) ◽

pp. 524-530 ◽

Cited By ~ 3

Author(s):

G. W. Lennon

Keyword(s):

Sea Level ◽

World Ocean ◽

Equipotential Surface ◽

Scientific Discipline ◽

Mean Sea Level ◽

Sea Levels ◽

Coastal Sea ◽

Long Time ◽

Marine System

The use of mean sea level as a surface of reference that might provide an independent control for geodetic leveling has been a long term goal arising from the classical analogy between the geoid as an equipotential surface and the surface assumed by a hypothetical undisturbed world ocean. The problems associated with this aim are now known to be vast, and are associated with the dynamics of the marine system, notably its response to meteorological forces, to variations in density and to the effects of basic circulation patterns. In consequence the mean sea level surface varies rapidly in both time and space. This identifies in fact a distinctive scientific discipline, coastal geodesy, in which contributions are required by both geodesists and oceanographers. It has come to be recognized that the coastal zone is a hazardous environment for all observational techniques concerned. On the one hand, the difficulties of measurement of coastal sea levels have only recently been understood; on the other hand, precise leveling procedures are now known to be influenced by the attraction of marine tides and by crustal deformation of tidal loading. Much of the data available for study are therefore inadequate and, moreover, it should be noted that long-time series are required. It is now possible to lay plans for both geodetic and oceanographic procedures to remedy these deficiencies in the long-term interests of the study.

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