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Author
Zou, M. ; Xiong, X. ; Wu, Z. ; Li, S. ; Zhang, Y. ; Chen, L.
Title
Increase of Atmospheric Methane Observed from Space-Borne and Ground-Based Measurements
Type
$loc['typeJournal Article']
Year
2019
Publication
Remote Sensing
Abbreviated Journal
Remote Sensing
Volume
11
Issue
8
Pages
Keywords
Methane increase trend ; Boundary layer ; Mid-upper troposphere ; Satellite ; AIRS
Abstract
It has been found that the concentration of atmospheric methane (CH4) has rapidly increased since 2007 after a decade of nearly constant concentration in the atmosphere. As an important greenhouse gas, such an increase could enhance the threat of global warming. To better quantify this increasing trend, a novel statistic method, i.e. the Ensemble Empirical Mode Decomposition (EEMD) method, was used to analyze the CH4 trends from three different measurements: the mid-upper tropospheric CH4 (MUT) from the space-borne measurements by the Atmospheric Infrared Sounder (AIRS), the CH4 in the marine boundary layer (MBL) from NOAA ground-based in-situ measurements, and the column-averaged CH4 in the atmosphere (X-CH4) from the ground-based up-looking Fourier Transform Spectrometers at Total Carbon Column Observing Network (TCCON) and the Network for the Detection of Atmospheric Composition Change (NDACC). Comparison of the CH4 trends in the mid-upper troposphere, lower troposphere, and the column average from these three data sets shows that, overall, these trends agree well in capturing the abrupt CH4 increase in 2007 (the first peak) and an even faster increase after 2013 (the second peak) over the globe. The increased rates of CH4 in the MUT, as observed by AIRS, are overall smaller than CH4 in MBL and the column-average CH4. During 2009-2011, there was a dip in the increase rate for CH4 in MBL, and the MUT-CH4 increase rate was almost negligible in the mid-high latitude regions. The increase of the column-average CH4 also reached the minimum during 2009-2011 accordingly, suggesting that the trends of CH4 are not only impacted by the surface emission, however that they also may be impacted by other processes like transport and chemical reaction loss associated with [OH]. One advantage of the EEMD analysis is to derive the monthly rate and the results show that the frequency of the variability of CH4 increase rates in the mid-high northern latitude regions is larger than those in the tropics and southern hemisphere.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
2072-4292
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1055
Permanent link to this record
Author
Davidson, F. ; Alvera-Azcárate, A. ; Barth, A. ; Brassington, G.B. ; Chassignet, E.P. ; Clementi, E. ; De Mey-Frémaux, P. ; Divakaran, P. ; Harris, C. ; Hernandez, F. ; Hogan, P. ; Hole, L.R. ; Holt, J. ; Liu, G. ; Lu, Y. ; Lorente, P. ; Maksymczuk, J. ; Martin, M. ; Mehra, A. ; Melsom, A. ; Mo, H. ; Moore, A. ; Oddo, P. ; Pascual, A. ; Pequignet, A.-C. ; Kourafalou, V. ; Ryan, A. ; Siddorn, J. ; Smith, G. ; Spindler, D. ; Spindler, T. ; Stanev, E.V. ; Staneva, J. ; Storto, A. ; Tanajura, C. ; Vinayachandran, P.N. ; Wan, L. ; Wang, H. ; Zhang, Y. ; Zhu, X. ; Zu, Z.
Title
Synergies in Operational Oceanography: The Intrinsic Need for Sustained Ocean Observations
Type
$loc['typeJournal Article']
Year
2019
Publication
Frontiers in Marine Science
Abbreviated Journal
Front. Mar. Sci.
Volume
6
Issue
Pages
Keywords
Abstract
Operational oceanography can be described as the provision of routine oceanographic information needed for decision-making purposes. It is dependent upon sustained research and development through the end-to-end framework of an operational service, from observation collection to delivery mechanisms. The core components of operational oceanographic systems are a multi-platform observation network, a data management system, a data assimilative prediction system, and a dissemination/accessibility system. These are interdependent, necessitating communication and exchange between them, and together provide the mechanism through which a clear picture of ocean conditions, in the past, present, and future, can be seen. Ocean observations play a critical role in all aspects of operational oceanography, not only for assimilation but as part of the research cycle, and for verification and validation of products. Data assimilative prediction systems are advancing at a fast pace, in tandem with improved science and the growth in computing power. To make best use of the system capability these advances would be matched by equivalent advances in operational observation coverage. This synergy between the prediction and observation systems underpins the quality of products available to stakeholders, and justifies the need for sustained ocean observations. In this white paper, the components of an operational oceanographic system are described, highlighting the critical role of ocean observations, and how the operational systems will evolve over the next decade to improve the characterization of ocean conditions, including at finer spatial and temporal scales.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
2296-7745
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1083
Permanent link to this record
Author
Zhang, M. ; Zhang, Y. ; Shu, Q. ; Zhao, C. ; Wang, G. ; Wu, Z. ; Qiao, F.
Title
Spatiotemporal evolution of the chlorophyll a trend in the North Atlantic Ocean
Type
$loc['typeJournal Article']
Year
2018
Publication
The Science of the Total Environment
Abbreviated Journal
Sci Total Environ
Volume
612
Issue
Pages
1141-1148
Keywords
Chlorophyll a ; Dipole pattern ; Multidimensional ensemble empirical mode decomposition ; Propagation ; Spatiotemporal evolution ; The variable trend
Abstract
Analyses of the chlorophyll a concentration (chla) from satellite ocean color products have suggested the decadal-scale variability of chla linked to the climate change. The decadal-scale variability in chla is both spatially and temporally non-uniform. We need to understand the spatiotemporal evolution of chla in decadal or multi-decadal timescales to better evaluate its linkage to climate variability. Here, the spatiotemporal evolution of the chla trend in the North Atlantic Ocean for the period 1997-2016 is analyzed using the multidimensional ensemble empirical mode decomposition method. We find that this variable trend signal of chla shows a dipole pattern between the subpolar gyre and along the Gulf Stream path, and propagation along the opposite direction of the North Atlantic Current. This propagation signal has an overlapping variability of approximately twenty years. Our findings suggest that the spatiotemporal evolution of chla during the two most recent decades is part of the multidecadal variations and possibly regulated by the changes of Atlantic Meridional Overturning Circulation, whereas the mechanisms of such evolution patterns still need to be explored.
Address
First Institute of Oceanography, State Oceanic Administration, Qingdao, China; Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Key Laboratory of Data Analysis and Applications, State Oceanic Administration, Qingdao, China. Electronic address: qiaofl@fio.org.cn
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
English
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0048-9697
ISBN
Medium
Area
Expedition
Conference
Funding
PMID:28892858
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
363
Permanent link to this record
Author
Chen, X. ; Zhang, Y. ; Zhang, M. ; Feng, Y. ; Wu, Z. ; Qiao, F. ; Huang, N.E.
Title
Intercomparison between observed and simulated variability in global ocean heat content using empirical mode decomposition, part I: modulated annual cycle
Type
$loc['typeJournal Article']
Year
2013
Publication
Climate Dynamics
Abbreviated Journal
Clim Dyn
Volume
41
Issue
11-12
Pages
2797-2815
Keywords
Ocean heat content ; Modulated annual cycle ; Empirical mode decomposition ; Instantaneous frequency ; Instantaneous amplitude ; CMIP3
Abstract
Address
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Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0930-7575
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
209
Permanent link to this record