Records
Author
Deng, J. ; Wu, Z. ; Zhang, M. ; Huang, N.E. ; Wang, S. ; Qiao, F.
Title
Using Holo-Hilbert spectral analysis to quantify the modulation of Dansgaard-Oeschger events by obliquity
Type
$loc['typeJournal Article']
Year
2018
Publication
Quaternary Science Reviews
Abbreviated Journal
Quaternary Science Reviews
Volume
192
Issue
Pages
282-299
Keywords
Pleistocene ; Paleoclimatology ; Greenland ; Antarctica ; Data treatment ; Data analysis ; Dansgaard-oeschger (DO) events ; Obliquity forcing ; Phase preference ; Holo-hilbert spectral analysis ; Amplitude modulation ; EMPIRICAL MODE DECOMPOSITION ; GREENLAND ICE-CORE ; NONSTATIONARY TIME-SERIES ; ABRUPT CLIMATE-CHANGE ; LAST GLACIAL PERIOD ; NORTH-ATLANTIC ; MILLENNIAL-SCALE ; RECORDS ; VARIABILITY ; CYCLE
Abstract
Astronomical forcing (obliquity and precession) has been thought to modulate Dansgaard-Oeschger (DO) events, yet the detailed quantification of such modulations has not been examined. In this study, we apply the novel Holo-Hilbert Spectral Analysis (HHSA) to five polar ice core records, quantifying astronomical forcing's time-varying amplitude modulation of DO events and identifying the preferred obliquity phases for large amplitude modulations. The unique advantages of HHSA over the widely used windowed Fourier spectral analysis for quantifying astronomical forcing's nonlinear modulations of DO events is first demonstrated with a synthetic data that closely resembles DO events recorded in Greenland ice cores (NGRIP, GRIP, and GISP2 cores on GICC05 modelext timescale). The analysis of paleoclimatic proxies show that statistically significantly more frequent DO events, with larger amplitude modulation in the Greenland region, tend to occur in the decreasing phase of obliquity, especially from its mean value to its minimum value. In the eastern Antarctic, although statistically significantly more DO events tend to occur in the decreasing obliquity phase in general, the preferred phase of obliquity for large amplitude modulation on DO events is a segment of the increasing phase near the maximum obliquity, implying that the physical mechanisms of DO events may be different for the two polar regions. Additionally, by using cross-spectrum and magnitude-squared analyses, Greenland DO mode at a timescale of about 1400 years leads the Antarctic DO mode at the same timescale by about 1000 years. (C) 2018 Elsevier Ltd. All rights reserved.
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Summary Language
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Series Editor
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Series Volume
Series Issue
Edition
ISSN
0277-3791
ISBN
Medium
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Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
971
Permanent link to this record
Author
Hou, T.Y. ; Yan, M.P. ; Wu, Z.
Title
A Variant Of The Emd Method For Multi-Scale Data
Type
$loc['typeJournal Article']
Year
2009
Publication
Advances in Adaptive Data Analysis
Abbreviated Journal
Adv. Adapt. Data Anal.
Volume
01
Issue
04
Pages
483-516
Keywords
Empirical Mode Decomposition (EMD) ; adaptive data analysis ; sparse representation
Abstract
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Publisher
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Series Editor
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Edition
ISSN
1793-5369
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Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
670
Permanent link to this record
Author
Huang, T. ; Armstrong, E.M. ; Bourassa, M.A. ; Cram, T.A. ; Elya, J. ; Greguska, F. ; Jacob, J.C. ; Ji, Z. ; Jiang, Y. ; Li, Y. ; Quach, N.T. ; McGibbney, L.J. ; Smith, S.R. ; Wilson, B.D. ; Worley S.J. ; Yang, C.
Title
An Integrated Data Analytics Platform
Type
$loc['typeJournal Article']
Year
2019
Publication
Marine Science
Abbreviated Journal
Mar. Sci.
Volume
6
Issue
Pages
Keywords
big data, Cloud computing, Ocean science, data analysis, Matchup, anomaly detection, open source
Abstract
An Integrated Science Data Analytics Platform is an environment that enables the confluence of resources for scientific investigation. It harmonizes data, tools and computational resources to enable the research community to focus on the investigation rather than spending time on security, data preparation, management, etc. OceanWorks is a NASA technology integration project to establish a cloud-based Integrated Ocean Science Data Analytics Platform for big ocean science at NASA�s Physical Oceanography Distributed Active Archive Center (PO.DAAC) for big ocean science. It focuses on advancement and maturity by bringing together several NASA open-source, big data projects for parallel analytics, anomaly detection, in situ to satellite data matchup, quality-screened data subsetting, search relevancy, and data discovery. Our communities are relying on data available through distributed data centers to conduct their research. In typical investigations, scientists would (1) search for data, (2) evaluate the relevance of that data, (3) download it, and (4) then apply algorithms to identify trends, anomalies, or other attributes of the data. Such a workflow cannot scale if the research involves a massive amount of data or multi-variate measurements. With the upcoming NASA Surface Water and Ocean Topography (SWOT) mission expected to produce over 20PB of observational data during its 3-year nominal mission, the volume of data will challenge all existing Earth Science data archival, distribution and analysis paradigms. This paper discusses how OceanWorks enhances the analysis of physical ocean data where the computation is done on an elastic cloud platform next to the archive to deliver fast, web-accessible services for working with oceanographic measurements.
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Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1038
Permanent link to this record
Author
Wu, Z. ; Huang, N.E.
Title
Ensemble Empirical Mode Decomposition: A Noise-Assisted Data Analysis Method
Type
$loc['typeJournal Article']
Year
2009
Publication
Advances in Adaptive Data Analysis
Abbreviated Journal
Adv. Adapt. Data Anal.
Volume
01
Issue
01
Pages
1-41
Keywords
Empirical Mode Decomposition (EMD) ; ensemble empirical mode decompositions ; noise-assisted data analysis (NADA) ; Intrinsic Mode Function (IMF) ; shifting stoppage criteria ; end effect reduction Read More: http://www.worldscientific.com/doi/abs/10.1142/S1793536909000047
Abstract
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ISSN
1793-5369
ISBN
Medium
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Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
667
Permanent link to this record
Author
Wu, Z. ; Feng, J. ; Qiao, F. ; Tan, Z.-M.
Title
Fast multidimensional ensemble empirical mode decomposition for the analysis of big spatio-temporal datasets
Type
$loc['typeJournal Article']
Year
2016
Publication
Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Abbreviated Journal
Philos Trans A Math Phys Eng Sci
Volume
374
Issue
2065
Pages
20150197
Keywords
adaptive and local data analysis ; data compression ; empirical orthogonal function ; fast algorithm ; multidimensional ensemble empirical mode decomposition ; principal component analysis
Abstract
In this big data era, it is more urgent than ever to solve two major issues: (i) fast data transmission methods that can facilitate access to data from non-local sources and (ii) fast and efficient data analysis methods that can reveal the key information from the available data for particular purposes. Although approaches in different fields to address these two questions may differ significantly, the common part must involve data compression techniques and a fast algorithm. This paper introduces the recently developed adaptive and spatio-temporally local analysis method, namely the fast multidimensional ensemble empirical mode decomposition (MEEMD), for the analysis of a large spatio-temporal dataset. The original MEEMD uses ensemble empirical mode decomposition to decompose time series at each spatial grid and then pieces together the temporal-spatial evolution of climate variability and change on naturally separated timescales, which is computationally expensive. By taking advantage of the high efficiency of the expression using principal component analysis/empirical orthogonal function analysis for spatio-temporally coherent data, we design a lossy compression method for climate data to facilitate its non-local transmission. We also explain the basic principles behind the fast MEEMD through decomposing principal components instead of original grid-wise time series to speed up computation of MEEMD. Using a typical climate dataset as an example, we demonstrate that our newly designed methods can (i) compress data with a compression rate of one to two orders; and (ii) speed-up the MEEMD algorithm by one to two orders.
Address
School of Atmospheric Sciences, Nanjing University, Nanjing, Jiangsu Province, People's Republic of China
Corporate Author
Thesis
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Place of Publication
Editor
Language
English
Summary Language
Original Title
Series Editor
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Series Volume
Series Issue
Edition
ISSN
1364-503X
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Funding
PMID:26953173; PMCID:PMC4792406
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
57
Permanent link to this record