Seasonality of UK′37 temperature estimates as inferred from sediment trap data

Abstract The seasonality of sea surface temperatures (SST) estimated from the alkenone- U K ′ 37 index has been a debated issue since the development of the proxy. Using a compilation of sediment trap time series data from 34 sampling locations, we show that the seasonality of maximum alkenone flux in sediment traps varies markedly across the oceans, depending not only on latitude and light availability but also on local oceanographic conditions. The seasonality of the alkenone flux to sediments may also be shaped by the complexity of sedimentation processes and a consistent, globally applicable, seasonal pattern is not apparent. Nevertheless, U K ′ 37 values display a world ocean scale correlation with mean annual SSTs (0 m) that closely resembles the standard calibration equation now established for modern surface sediment records. Thus, with a few notable exceptions at oceanographic locations proximate to major hydrographic fronts, it can be concluded that the integrated sedimentation patterns for U K ′ 37 measured in sediment trap time series provide a measure of annual mean SST.

[1]  C. Jeandel,et al.  Hydrocarbons, sterols and alkenones in sinking particles in the Indian Ocean sector of the Southern Ocean , 1998 .

[2]  R. Harris,et al.  Genetic and physiological influences on the alkenone/alkenoate versus growth temperature relationship in Emiliania huxleyi and Gephyrocapsa oceanica , 1998 .

[3]  Margo Project Members.  Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum , 2009 .

[4]  N. Harada,et al.  Alkenones and particulate fluxes in sediment traps from the central equatorial Pacific , 2001 .

[5]  M. Wakatsuchi,et al.  Time-series sediment trap record of alkenones from the western Sea of Okhotsk , 2007 .

[6]  M. Sarnthein,et al.  ATLANTIC CORE-TOP CALIBRATION OF THE U37K INDEX AS A SEA-SURFACE PALAEOTEMPERATURE INDICATOR , 1995 .

[7]  T. Herbert,et al.  Depth and seasonality of alkenone production along the California Margin inferred from a core top transect , 1998 .

[8]  T. Nakatsuka,et al.  Production and transport of long-chain alkenones and alkyl alkenoates in a sea water column in the northwestern Pacific off central Japan , 1998 .

[9]  Richard A. Krishfield,et al.  Particulate organic carbon fluxes to the ocean interior and factors controlling the biological pump: A synthesis of global sediment trap programs since 1983 , 2008 .

[10]  F. Prahl,et al.  Annual biomarker record for export production in the central Arabian Sea , 2000 .

[11]  E. Bard,et al.  Core-top calibration of the Uk37 versus sea surface temperature in the Indian Ocean , 1997 .

[12]  J. Duinker,et al.  Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea , 1998 .

[13]  Timothy P. Boyer,et al.  World ocean atlas 2001 : objective analyses, data statistics, and figures : CD-ROM documentation , 2002 .

[14]  H. Kawahata,et al.  Comparison of settling particles and sediments at IMAGES coring site in the northwestern North Pacific — Effect of resuspended particles on paleorecords , 2009 .

[15]  N. Harada,et al.  Characteristics of alkenone distributions in suspended and sinking particles in the northwestern North Pacific , 2006 .

[16]  M. Chapman,et al.  Faunal and alkenone reconstructions of subtropical North Atlantic surface hydrography and paleotemperature over the last 28 kyr , 1996 .

[17]  M. Sicre,et al.  Evaluation of long-chain alkenones as paleo-temperature indicators in the Mediterranean Sea , 1997 .

[18]  S. Doney,et al.  Mesoscale variability in time series data: Satellite-based estimates for the U.S. JGOFS Bermuda Atlantic Time-Series Study (BATS) site , 2002 .

[19]  A. Mix,et al.  Alkenone paleothermometry: Biological lessons from marine sediment records off western South America , 2006 .

[20]  Ken Caldeira,et al.  Seasonal rhythms of net primary production and particulate organic carbon flux to depth describe the efficiency of biological pump in the global ocean , 2007 .

[21]  R. Thunell,et al.  Generation, transport, and preservation of the alkenone‐based U37K′ sea surface temperature index in the water column and sediments of the Cariaco Basin (Venezuela) , 2004 .

[22]  A. Rosell‐Melé,et al.  Core-top calibration of the alkenone index vs sea surface temperature in the Indian Ocean , 1997 .

[23]  S. Nodder,et al.  Alkenone temperature records and biomarker flux at the subtropical front on the chatham rise, SW Pacific Ocean , 2005 .

[24]  G. Eglinton,et al.  Molecular stratigraphy: a new tool for climatic assessment , 1986, Nature.

[25]  F. Prahl,et al.  Ecology and biogeochemistry of alkenone production at Station ALOHA , 2005 .

[26]  F. Prahl,et al.  A biomarker perspective on prymnesiophyte productivity in the northeast pacific ocean , 1993 .

[27]  G. Eglinton,et al.  Long-chain alkenones and alkyl alkenoates as palaeotemperature indicators: their production, flux and early sedimentary diagenesis in the Eastern North Atlantic , 1992 .

[28]  G. Leduc,et al.  Holocene and Eemian sea surface temperature trends as revealed by alkenone and Mg/Ca paleothermometry , 2010 .

[29]  T. Fukuhara,et al.  Seasonal and depth variations in molecular and isotopic alkenone composition of sinking particles from the western North Pacific , 2007 .

[30]  J. Marty,et al.  Alkenones in the northwestern Mediterranean Sea: Interannual variability and vertical transfer , 1999 .

[31]  M. Conte,et al.  Global temperature calibration of the alkenone unsaturation index (UK′37) in surface waters and comparison with surface sediments , 2006 .

[32]  J. Marty,et al.  Production pattern of alkenones in the Mediterranean Sea , 1996 .

[33]  F. Prahl,et al.  Systematic pattern in U37K′ – Temperature residuals for surface sediments from high latitude and other oceanographic settings , 2010 .

[34]  W. Rijpstra,et al.  On the occurrence and structural identification of long chain unsaturated ketones and hydrocarbons in sediments , 1980 .

[35]  C. Rühlemann,et al.  Alkenone temperature anomalies in the Brazil‐Malvinas Confluence area caused by lateral advection of suspended particulate material , 2006 .

[36]  G. Eglinton,et al.  Alkenone and alkenoate distributions within the euphotic zone of the eastern North Atlantic: correlation with production temperature , 1993 .

[37]  P. Müller,et al.  Anomalously low alkenone temperatures caused by lateral particle and sediment transport in the Malvinas Current region, western Argentine Basin , 2000 .

[38]  David A. Siegel,et al.  Climate-driven trends in contemporary ocean productivity , 2006, Nature.

[39]  G. Leduc,et al.  Disentangling seasonal signals in Holocene climate trends by satellite-model-proxy integration , 2010 .

[40]  M. Conte,et al.  Episodic particle flux in the deep Sargasso Sea: an organic geochemical assessment , 1998 .

[41]  A. Oschlies,et al.  Interannual variability of deep water particle flux in relation to production and lateral sources in the northeast Atlantic , 2005 .

[42]  M. Gonda,et al.  The trans-activator gene of HTLV-III is essential for virus replication , 1986, Nature.

[43]  T. Herbert,et al.  Alkenone unsaturation in surface sediments from the eastern equatorial Pacific: Implications for SST reconstructions , 2012 .

[44]  C. Thomsen.  Verfolgung pelagischer Prozesse mit Hilfe von biochemischen Komponenten am Beispiel der Alkenone (C37:2, C37:3) , 1993 .

[45]  Richard A. Krishfield,et al.  Factors controlling the flux of organic carbon to the bathypelagic zone of the ocean , 2002 .

[46]  A. Rosell‐Melé,et al.  Calibration of the alkenone paleotemperature index U37K′ based on core-tops from the eastern South Atlantic and the global ocean (60°N-60°S) , 1998 .

[47]  R. Thunell,et al.  Oceanographic considerations for the application of the alkenone-based paleotemperature U , 2001 .

[48]  H. Kawahata,et al.  Depth ranges of alkenone production in the central Pacific Ocean , 1999 .

[49]  W. Howard,et al.  Glacial-interglacial sea surface temperature changes across the subtropical front east of New Zealand based on alkenone unsaturation ratios and foraminiferal assemblages , 2002 .

[50]  J. Farrington,et al.  Use of the alkenone unsaturation ratio U37k to determine past sea surface temperatures: core-top SST calibrations and methodology considerations , 1991 .

[51]  F. Muller‐Karger,et al.  Biogenic fluxes in the Cariaco Basin: a combined study of sinking particulates and underlying sediments , 2003 .

[52]  S. Noriki,et al.  Sediment trap record of alkenones from the East Sea (Japan Sea) , 2011 .

[53]  L. Beaufort,et al.  Long-chain alkenones and U37k′ variability along a south–north transect in the Western Pacific Ocean , 2002 .

[54]  A. Rosell‐Melé,et al.  Alkenone fluxes and anomalous U37K′ values during 1989–1990 in the Northeast Atlantic (48°N 21°W) , 2000 .

[55]  M. Kageyama,et al.  Comparing proxies for the reconstruction of LGM sea-surface conditions in the northern North Atlantic , 2006 .

[56]  A. Mather,et al.  Generation, transport and preservation of armoured mudballs in an ephemeral gully system , 2008 .

[57]  F. Joos,et al.  The role of Southern Ocean processes in orbital and millennial CO2 variations – A synthesis , 2010 .

[58]  E. Calvo,et al.  The upper end of the UK′37 temperature calibration revisited , 2003 .

[59]  G. Haug,et al.  North Pacific seasonality and the glaciation of North America 2.7 million years ago , 2005, Nature.

[60]  Laurel A Muehlhausen,et al.  Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions , 1988 .

[61]  F. Prahl,et al.  Biomarker temperature estimates for modern and last glacial surface waters of the California Current , 1997 .

[62]  C. Pilskaln,et al.  Seasonal record for alkenones in sedimentary particles from the Gulf of Maine , 2001 .

[63]  E. Bard.  Comparison of alkenone estimates with other paleotemperature proxies , 2001 .

[64]  X. Giraud.  Modelling an alkenone-like proxy record in the NW African upwelling , 2006 .

[65]  E. Sikes,et al.  Comparison of U37k′ and diatom assemblage sea surface temperature estimates with atlas derived data in Holocene sediments from the Southern West Indian Ocean , 1998 .

[66]  F. Prahl,et al.  Growth phase dependent hydrogen isotopic fractionation in alkenone-producing haptophytes , 2009 .

[67]  F. Prahl,et al.  Calibration of unsaturation patterns in long-chain ketone compositions for palaeotemperature assessment , 1987, Nature.

[68]  A. Rosell‐Melé,et al.  Links between iron supply, marine productivity, sea surface temperature, and CO2 over the last 1.1 Ma , 2009 .

[69]  A. Rosell‐Melé,et al.  Distributions of UK37 and UK37′ in the surface waters and sediments of the Nordic Seas: Implications for paleoceanography , 2004 .

[70]  A. Knap,et al.  Transient physical forcing of pulsed export of bioreactive material to the deep Sargasso Sea , 2003 .

[71]  G. Eglinton,et al.  Long-chain alkenes and alkenones in the marine coccolithophorid Emiliania huxleyi , 1980 .

[72]  G. Fischer,et al.  A 4-year sediment trap record of alkenones from the filamentous upwelling region off Cape Blanc, NW Africa and a comparison with distributions in underlying sediments , 2001 .