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| Registros recuperados: 69 | |
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| Ho, Sze Ling; Laepple, Thomas. |
| Knowledge of the magnitude of the Last Glacial Maximum (LGM) cooling is a useful constraint for estimating the climate sensitivity used in projecting future climate change. Proxy comparison, especially that between the alkenone-based U-37(K ') and the archaeal tetraether-based TEX86, has been increasingly applied in paleoceanographic studies as a measure to better constrain proxy-derived temperature estimates. In this study, we compile and compare published multiproxy (U-37(K ') and TEX86H) records of glacial cooling measured on the same sediment cores. In spite of the diversity in oceanographic and sedimentation settings spanned by the study sites, we find that the TEX86H-derived mean tropical LGM cooling is approximately twice as strong as that suggested... |
| Tipo: Text |
Palavras-chave: Last Glacial Maximum; Sea surface temperature; Multiproxy; PMIP3; U-37(K '); TEX86H. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46297/45933.pdf |
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| Tandeo, Pierre; Ailliot, Pierre; Autret, Emmanuelle. |
| Satellites provide important information on many meteorological and oceanographic variables. State-space models are commonly used to analyse such data sets with measurement errors. In this work, we propose to extend the usual linear and Gaussian state-space to analyse time series with irregular time sampling, such as the one obtained when keeping all the satellite observations available at some specific location. We discuss the parameter estimation using a method of moment and the method of maximum likelihood. Simulation results indicate that the method of moment leads to a computationally efficient and numerically robust estimation procedure suitable for initializing the Expectation-Maximisation algorithm, which is combined with a standard numerical... |
| Tipo: Text |
Palavras-chave: State-space model; Irregular sampling; Ornstein-Uhlenbeck process; EM algorithm; Sea surface temperature. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00039/15047/12441.pdf |
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| Barrows, Timothy T.; Juggins, Steve; De Deckker, Patrick; Calvo, Eva; Pelejero, Carles. |
| We compile and compare data for the last 150,000 years from four deep-sea cores in the midlatitude zone of the Southern Hemisphere. We recalculate sea surface temperature estimates derived from foraminifera and compare these with estimates derived from alkenones and magnesium/calcium ratios in foraminiferal carbonate and with accompanying sedimentological and pollen records on a common absolute timescale. Using a stack of the highest-resolution records, we find that first-order climate change occurs in concert with changes in insolation in the Northern Hemisphere. Glacier extent and inferred vegetation changes in Australia and New Zealand vary in tandem with sea surface temperatures, signifying close links between oceanic and terrestrial temperature. In... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; Climate change; Australia–New Zealand. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00238/34941/33245.pdf |
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| Robinson, Ian; Piolle, Jean-francois; Leborgne, Pierre; Poulter, David; Donlon, Craig; Arino, Olivier. |
| For over a decade the ATSR series of sensors produced high quality SST data products, but the narrow swath did not encourage their use for operational tasks. This changed in 2005 when the European Space Agency's Medspiration Service introduced AATSR data in the GHRSST L2P format. This paper describes the opportunities provided by the Medspiration system for facilitating the complementary use of SST products from AATSR and from other satellite sensors. It explains how, following the implementation by Medspiration of GHRSST procedures, data products and tools, AATSR data are now being used around the world to complement the use of other sources of SST and to facilitate bias adjustments between them. Despite the limited daily coverage of AATSR its broadly... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; Operational Oceanography; AATSR; Medspiration Service; Group for high resolution sea surface temperature (GHRSST). |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00057/16867/15850.pdf |
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| He, Juan; Zhao, Meixun; Li, Li; Wang, Pinxian; Ge, Huangmin. |
| This paper reports high-resolution biomarker records of the last 260 ka for core MD05- 2904 from the northern South China Sea (SCS). The sea surface temperature (SST) record using the U-37(k') index reveals a minimum of 21.5 degrees C (MIS 2) and a maximum of 28.3 degrees C (MIS 5.5), for a temperature difference of almost 7 degrees C, and provides the longest high-resolution U-37(k') SST record in northern SCS. The content of odd-number long chain n-alkanes and several n-alkanes indexes such as the CPI, ACL and the C-31/C-27 ratio, all reveal generally higher values during the glacials and lower values during the interglacials. Terrestrial input as indicated by n-alkane content was mostly controlled by sea-level changes: During the glacials, lower... |
| Tipo: Text |
Palavras-chave: Northern South China Sea; Sea surface temperature; Terrestrial input; Source region vegetation. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31844/30259.pdf |
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| Davis, Catherine V.; Myhre, Sarah E.; Deutsch, Curtis; Caissie, Beth; Praetorius, Summer; Borreggine, Marisa; Thunell, Robert. |
| Deglacial sea surface conditions in the subarctic North Pacific and marginal seas are the subject of increasing interest in paleoceanography. However, a cohesive picture of near-surface oceanography from which to compare inter and intra-regional variability through the last deglaciation is lacking. We present a synthesis of sea surface temperature covering the open North Pacific and its marginal seas, spanning the past 20 ka using proxy records from foraminiferal calcite (δ18O and Mg/Ca) and coccolithophore alkenones (Uk’37). Sea surface temperature proxies tend to be in agreement through the Holocene, though Uk’37 records are often interpreted as warmer than adjacent δ18O or Mg/Ca records during the Last Glacial Maximum and early deglaciation. In the Sea... |
| Tipo: Text |
Palavras-chave: Sea surface temperature; North Pacific; Bering sea; Sea of Okhotsk; Deglaciation. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00646/75814/76758.pdf |
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| Cortese, G.; Dunbar, G. B.; Carter, L.; Scott, G.; Bostock, H.; Bowen, M.; Crundwell, M.; Hayward, B. W.; Howard, W.; Martinez, J.l.; Moy, A.; Neil, H.; Sabaa, A.; Sturm, A.. |
| Paleoceanographic archives derived from 17 marine sediment cores reconstruct the response of the Southwest Pacific Ocean to the peak interglacial, Marine Isotope Stage (MIS) 5e (ca. 125ka). Paleo-Sea Surface Temperature (SST) estimates were obtained from the Random Forest modelan ensemble decision tree toolapplied to core-top planktonic foraminiferal faunas calibrated to modern SSTs. The reconstructed geographic pattern of the SST anomaly (maximum SST between 120 and 132ka minus mean modern SST) seems to indicate how MIS 5e conditions were generally warmer in the Southwest Pacific, especially in the western Tasman Sea where a strengthened East Australian Current (EAC) likely extended subtropical influence to ca. 45 degrees S off Tasmania. In contrast, the... |
| Tipo: Text |
Palavras-chave: Interglacial climate; Foraminifera; South Pacific Ocean; Marine Isotope Stage 5; Sea surface temperature. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37492/36995.pdf |
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| Barton, Benjamin I.; Lenn, Yueng-djern; Lique, Camille. |
| Barents Sea Water (BSW) is formed from Atlantic Water that is cooled through atmospheric heat loss and freshened through seasonal sea ice melt. In the eastern Barents Sea, the BSW and fresher, colder Arctic Water meet at the surface along the Polar Front (PF). Despite its importance in setting the northern limit of BSW ventilation, the PF has been poorly-documented, mostly eluding detection by observational surveys that avoid seasonal sea ice. In this study, satellite sea surface temperature (SST) observations are used in addition to a temperature and salinity climatology to examine the location and structure of the PF, and characterise its variability over the period 1985 – 2016. It is shown that the PF is independent of the position of the sea ice edge... |
| Tipo: Text |
Palavras-chave: Arctic; Sea ice; Fronts; Sea surface temperature; Satellite observations. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00448/56003/57509.pdf |
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| He, Juan; Zhao, Meixun; Li, Li; Wang, Hui; Wang, Pinxian. |
| High-resolution molecular abundance records for several marine biomarkers during the last glacial and Holocene have been generated for core MD05-2904 (19 degrees 27.32'N, 116 degrees 15.15'E, 2066 in water depth) from the northern South China Sea. The U-37(K') SST record indicates a 4.4 degrees C cooling during the Last Glacial Maximum for this site, consistent with previous reconstructions. The contents Of C-37 alkenones, dinosterol, brassicasterol, and C-30 alkyl diols are used as productivity proxies for haptophytes, dinoflagellates, diatoms, and eustigmatophytes, respectively. These records reveal that both individual phytoplankton group and total productivity increased by several factors during the LGM compared with those for the Holocene, in response... |
| Tipo: Text |
Palavras-chave: Biomarkers; Paleo-productivity; Community structure; Sea surface temperature; South China Sea. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31845/30258.pdf |
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| Sokolov, Serguei; Rintoul, Stephen R.. |
| Maps of the gradient of sea surface height (SSH) and sea surface temperature (SST) reveal that the Antarctic Circumpolar Current (ACC) consists of multiple jets or frontal filaments. The braided and patchy nature of the gradient fields seems at odds with the traditional view, derived from hydrographic sections, that the ACC is made up of three continuous circumpolar fronts. By applying a nonlinear fitting procedure to 638 weekly maps of SSH gradient (del SSH), it is shown that the distribution of maxima in del SSH (i.e., fronts) is strongly peaked at particular values of absolute SSH (i.e., streamlines). The association between the jets and particular streamlines persists despite strong topographic and eddy - mean flow interactions, which cause the jets to... |
| Tipo: Text |
Palavras-chave: Jets; Currents; Sea surface temperature; Ocean circulation. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34616/32952.pdf |
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| Isern-fontanet, Jordi; Chapron, Bertrand; Lapeyre, Guillaume; Klein, Patrice. |
| In this paper, we examine the emerging potential offered by satellite microwave radiometer SST measurements to complement altimeter data to quantitatively derive surface ocean currents. The proposed methodology does not follow standard sequential temporal analysis but follows the application of the Surface Quasi-Geostrophic (SQG) theory. Accordingly, under favourable environmental conditions, the implementation for this methodology is simple and robust, and most importantly, solely requires a single SST image. For the present demonstration, altimetric measurements are used to infer a necessary adjustment to match the kinetic energy level for length scales smaller than 300 km. This helps to derive a regional effective Brunt-Vaisala frequency to produce SQG... |
| Tipo: Text |
Palavras-chave: Microwave radiometers; Sea surface temperature; Surface quasi geostrophy. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2177.pdf |
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| Chevane, C. M.; Penven, Pierrick; Nehama, F. P. J.; Reason, C. J. C.. |
| The Sofala Bank, a wide shelf located along the central coast of Mozambique, hosts tides with high amplitudes. The Regional Ocean Modelling System (ROMS) was used to analyse the tidal currents on the bank and to investigate their effects on the stratification and generation of tidal fronts. During spring tides, barotropic tidal currents with maximum values ranging from 40 cm s–1 to 70 cm s–1 are found on the central bank. The major axis of the tidal ellipses for M2 and S2 follow a cross-shelf direction with mainly anticlockwise rotation. Similar to observations, three distinct regimes occur: (i) a warm well-mixed region on the inner shelf where the depths are <30 m; (ii) a wellmixed colder region above the shelf edge; and (iii) a stratified region... |
| Tipo: Text |
Palavras-chave: Barotropic tidal currents; ROMS; Sea surface temperature; Shallow seas; Tidal front. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00362/47276/47852.pdf |
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| Shiau, Liang-jian; Yu, Pai-sen; Wei, Kuo-yen; Yamamoto, Masanobu; Lee, Teh-quei; Yu, Ein-fen; Fang, Tien-hsi; Chen, Min-te. |
| Variations in sea surface temperature (SST), productivity, and biogenic components such as total organic carbon (TOC), carbonate, and opal contents measured from IMAGES (International Marine Global Changes Study) core MD972142 provide information about long-term paleoceanographic changes during the past similar to 870000 years in the southeastern South China Sea (SCS). MD972142 U-37(k)-SSTs varied from 25 to 29 degrees C, paralleling the glacial to interglacial changes. MD972142 biogenic components show relatively high carbonate and opal, and low TOC contents in interglacial stages, and low carbonate and opal and high TOC contents in glacial stages, and these variations appear to be sensitive to regional terrestrial sediment input and productivity. Our... |
| Tipo: Text |
Palavras-chave: Total organic carbon; Carbonate; Opal; Productivity; Sea surface temperature; South China Sea; Monsoon; IMAGES. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34817/33682.pdf |
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| Drushka, Kyla; Asher, William E.; Sprintall, Janet; Gille, Sarah T.; Hoang, Clifford. |
| Surface salinity variability on O(1-10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40-100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity... |
| Tipo: Text |
Palavras-chave: Small scale processes; Freshwater; Fronts; Sea surface temperature; Oceanic variability. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00676/78805/81042.pdf |
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| Chang, Yuan-pin; Wang, Wei-lung; Yokoyama, Yusuke; Matsuzaki, Hiroyuki; Kawahata, Hodaka; Chen, Min-te. |
| High resolution planktic foraminifer fauna assemblage data are used to reconstruct the millennial-scale sea surface temperature (SST) variability of the past 40000 years at an IMAGES core site (MD012404) in the Okinawa Trough in the East China Sea (ECS). The fauna assemblages in core MD012404 are dominated by five species - Globigerinoides ruber, Globigerina bulloides, Neogloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globigerinita glutinata, which account for > 70% in relative abundance. Our Q-mode factor analysis decomposed the fauna abundance data into three factors, which indicate cold water mass, warm water mass, and possibly coastal water flow with low salinity in the ECS. The MD012404 fauna data show abrupt changes at similar to 16... |
| Tipo: Text |
Palavras-chave: Planktic foraminifer; Sea surface temperature; ITCZ; East China Sea; Okinawa Trough; IMAGES. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34818/33684.pdf |
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| Registros recuperados: 69 | |
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