Precipitation variability within the West Pacific Warm Pool over the past 120 ka: Evidence from the Davao Gulf, southern Philippines

Proxy records of hydrologic variability in the West Pacific Warm Pool (WPWP) have revealed wide-scale changes in past convective activity in response to orbital and suborbital climate forcings. However, attributing proxy responses to regional changes in WPWP hydrology versus local variations in precipitation requires independent records linking the terrestrial and marine realms. We present high-resolution stable isotope, U-37(K) sea surface temperature, X-ray fluorescence (XRF) core scanning, and coccolithophore-derived paleoproductivity records covering the past 120ka from International Marine Global Change (IMAGES) Program Core MD06-3075 (6 degrees 29N, 125 degrees 50E, water depth 1878m), situated in the Davao Gulf on the southern side of Mindanao. XRF-derived log(Fe/Ca) records provide a robust proxy for runoff-driven sedimentary discharge from Mindanao, while past changes in local productivity are associated with variable freshwater runoff and stratification of the surface layer. Significant precessional-scale variability in sedimentary discharge occurred during marine isotope stage (MIS) 5, with peaks in discharge contemporaneous with Northern Hemisphere summer insolation minima. We attribute these changes to the latitudinal migration of the Intertropical Convergence Zone (ITCZ) over the WPWP together with variability in the strength of the Walker circulation acting on precessional timescales. Between 60 and 15ka sedimentary discharge at Mindanao was muted, displaying little orbital- or millennial-scale variability, likely in response to weakened precessional insolation forcing and lower sea level driving increased subsidence of air masses over the exposed Sunda Shelf. These results highlight the high degree of local variability in the precipitation response to past climate changes in the WPWP.

[1]  Wolfgang Kuhnt,et al.  Mindanao Dome variability over the last 160 kyr: Episodic glacial cooling of the West Pacific Warm Pool , 2011 .

[2]  S. Clemens,et al.  Millennial and orbital variations of El Niño/Southern Oscillation and high-latitude climate in the last glacial period , 2004, Nature.

[3]  A. Mix,et al.  A multiproxy assessment of the western equatorial Pacific hydrography during the last 30 kyr , 2007 .

[4]  A. Timmermann,et al.  Assessing divergent SST behavior during the last 21 ka derived from alkenones and G. ruber-Mg/Ca in the equatorial Pacific , 2014 .

[5]  Yusuke Yokoyama,et al.  La Niña-like conditions in the eastern equatorial Pacific and a stronger Choco jet in the northern Andes during the last glaciation , 2003 .

[6]  D. Anderson,et al.  Glacial–interglacial stability of ocean pH inferred from foraminifer dissolution rates , 2002, Nature.

[7]  A. Rosell‐Melé,et al.  Temperature and Salinity Effects on Alkenone Ratios Measured in Surface Sediments from the Indian Ocean , 1997, Quaternary Research.

[8]  Martín Medina-Elizalde,et al.  The Mid-Pleistocene Transition in the Tropical Pacific , 2005, Science.

[9]  A. Mcintyre,et al.  Nutricline variation in the equatorial Atlantic coincident with the Younger Dryas , 1990 .

[10]  G. Weltje,et al.  Calibration of XRF core scanners for quantitative geochemical logging of sediment cores: Theory and application , 2008 .

[11]  G. Haug,et al.  Strong influence of water vapor source dynamics on stable isotopes in precipitation observed in Southern Meghalaya, NE India , 2010 .

[12]  Y. Rosenthal,et al.  East Asian monsoon forcing of suborbital variability in the Sulu Sea during Marine Isotope Stage 3: Link to Northern Hemisphere climate , 2003 .

[13]  D. Schrag,et al.  The oxygen isotopic composition of seawater during the Last Glacial Maximum , 2002 .

[14]  R. Schneider,et al.  155,000 Years of West African Monsoon and Ocean Thermal Evolution , 2007, Science.

[15]  H. Oerter,et al.  EDML1: a chronology for the EPICA deep ice core from Dronning Maud Land, Antarctica, over the last 150 000 years , 2007 .

[16]  J. Marshall,et al.  Changes in ITCZ location and cross-equatorial heat transport at the Last Glacial Maximum, Heinrich Stadial 1, and the mid-Holocene , 2014 .

[17]  A. Mix,et al.  ENSO-like forcing on oceanic primary production during the Late Pleistocene. , 2001, Science.

[18]  D. Lea,et al.  Climate impact of late quaternary equatorial pacific sea surface temperature variations , 2000, Science.

[19]  W. Humphreys,et al.  North Atlantic forcing of millennial-scale Indo-Australian monsoon dynamics during the Last Glacial period , 2013 .

[20]  R. L. Edwards,et al.  A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China , 2001, Science.

[21]  K. Lambeck,et al.  Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records , 2002 .

[22]  R. Edwards,et al.  Millennial‐scale precipitation changes in southern Brazil over the past 90,000 years , 2007 .

[23]  Pieter M. Grootes,et al.  GISP2 Oxygen Isotope Ratios , 2000, Quaternary Research.

[24]  H. Andruleit,et al.  Coccolithophores in surface sediments of the Arabian Sea in relation to environmental gradients in surface waters , 2002 .

[25]  K. Cobb,et al.  Varied Response of Western Pacific Hydrology to Climate Forcings over the Last Glacial Period , 2013, Science.

[26]  Jelle Bijma,et al.  Reevaluation of the oxygen isotopic composition of planktonic foraminifera: Experimental results and revised paleotemperature equations , 1998 .

[27]  Mathias Vuille,et al.  Insolation-driven changes in atmospheric circulation over the past 116,000 years in subtropical Brazil , 2005, Nature.

[28]  C. Gautier,et al.  A Satellite-derived Climatology of the ITCZ , 1993 .

[29]  Kim M. Cobb,et al.  Millennial-scale trends in west Pacific warm pool hydrology since the Last Glacial Maximum , 2007, Nature.

[30]  P. Grootes,et al.  The Leibniz-Labor AMS facility at the Christian-Albrechts University, Kiel, Germany , 1997 .

[31]  T. Guilderson,et al.  Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired 230 Th/ 234 U/ 238 U and 14 C dates on pristine corals , 2005 .

[32]  T. Schneider,et al.  Hadley Circulation Response to Orbital Precession. Part I: Aquaplanets , 2013 .

[33]  Gerald Müller,et al.  The 'Karbonat-Bombe', a simple device for the determination of carbonate content in sediment, soils, and other materials , 1971 .

[34]  Xiaohua Shao,et al.  Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years , 2008, Nature.

[35]  M. Cane.  A Role for the Tropical Pacific , 1998, Science.

[36]  Axel Timmermann,et al.  Southern Hemisphere and Deep-Sea Warming Led Deglacial Atmospheric CO2 Rise and Tropical Warming , 2007, Science.

[37]  G. Leduc,et al.  Holocene changes in eastern equatorial Atlantic salinity as estimated by water isotopologues , 2011 .

[38]  C. Ropelewski,et al.  Global and Regional Scale Precipitation Patterns Associated with the El Niño/Southern Oscillation , 1987 .

[39]  E. Cook,et al.  Variability in the El Niño-Southern Oscillation Through a Glacial-Interglacial Cycle , 2001, Science.

[40]  Athanasios Koutavas,et al.  El Niño-Like Pattern in Ice Age Tropical Pacific Sea Surface Temperature , 2002, Science.

[41]  J. Bjerknes.  ATMOSPHERIC TELECONNECTIONS FROM THE EQUATORIAL PACIFIC1 , 1969 .

[42]  Syaefudin,et al.  The water masses between Mindanao and New Guinea , 1996 .

[43]  P. Grootes,et al.  The Carbonate 14C Background and its Components at the Leibniz AMS Facility , 1997, Radiocarbon.

[44]  P. Xie,et al.  Global Precipitation: A 17-Year Monthly Analysis Based on Gauge Observations, Satellite Estimates, and Numerical Model Outputs , 1997 .

[45]  M. Hoerling,et al.  Tropical Origins for Recent North Atlantic Climate Change , 2001, Science.

[46]  M. Kölling,et al.  Influence of the water content on X‐ray fluorescence core‐scanning measurements in soft marine sediments , 2007 .

[47]  J. Tierney,et al.  The Influence of Indian Ocean Atmospheric Circulation on Warm Pool Hydroclimate During the Holocene Epoch , 2012 .

[48]  G. Schmidt,et al.  Seawater isotope constraints on tropical hydrology during the Holocene , 2007 .

[49]  J. Marshall,et al.  The Relationship between ITCZ Location and Cross-Equatorial Atmospheric Heat Transport: From the Seasonal Cycle to the Last Glacial Maximum , 2012 .

[50]  M. C. Jones,et al.  The Statistical Analysis of Compositional Data , 1986 .

[51]  Y. Rosenthal,et al.  Deglacial δ18O and hydrologic variability in the tropical Pacific and Indian Oceans , 2014 .

[52]  Vincent,et al.  Insolation cycles as a major control of equatorial indian ocean primary production , 1997, Science.

[53]  P. DiNezio,et al.  The effect of sea level on glacial Indo-Pacific climate , 2013 .

[54]  G. Vecchi,et al.  The response of the Walker circulation to Last Glacial Maximum forcing: Implications for detection in proxies , 2011 .

[55]  R. Edwards,et al.  The Global Paleomonsoon as seen through speleothem records from Asia and the Americas , 2012, Climate Dynamics.

[56]  William B. Curry,et al.  Improved oxygen isotope temperature calibrations for cosmopolitan benthic foraminifera , 2014 .

[57]  Gavin A. Schmidt,et al.  Global gridded data set of the oxygen isotopic composition in seawater , 2006 .

[58]  H. BergerW,et al.  深海底の有孔虫 リソクラインと溶解速度 | 文献情報 | J-GLOBAL 科学技術総合リンクセンター , 1982 .

[59]  R. Thunell,et al.  Super ENSO and Global Climate Oscillations at Millennial Time Scales , 2002, Science.

[60]  Ian Cartwright,et al.  Increasing Australian–Indonesian monsoon rainfall linked to early Holocene sea-level rise , 2009 .

[61]  Gerold Wefer,et al.  Correlated Millennial-Scale Changes in Surface Hydrography and Terrigenous Sediment Yield Inferred from Last-Glacial Marine Deposits off Northeastern Brazil , 1998, Quaternary Research.

[62]  J. Toole,et al.  Observations of the Pacific North Equatorial Current Bifurcation at the Philippine Coast , 1990 .

[63]  R. Seager,et al.  Orbital controls on the El Niño/Southern Oscillation and the tropical climate , 1999 .

[64]  R. Thunell,et al.  A bi-polar signal recorded in the western tropical Pacific: Northern and Southern Hemisphere climate records from the Pacific warm pool during the last Ice Age , 2009 .

[65]  Maurice Pagel,et al.  Oversampling of sedimentary series collected by giant piston corer: Evidence and corrections based on 3.5-kHz chirp profiles , 2004, Paleoceanography.

[66]  E. Bard,et al.  The precession phase of hydrological variability in the Western Pacific Warm Pool during the past 400 ka , 2011 .

[67]  M. Prange,et al.  North Atlantic forcing of tropical Indian Ocean climate , 2014, Nature.

[68]  H. Mitsudera,et al.  A Climatology of the Circulation and Water Mass Distribution near the Philippine Coast , 1999 .

[69]  M. Griffiths,et al.  Rapid interhemispheric climate links via the Australasian monsoon during the last deglaciation , 2013, Nature Communications.

[70]  K. Cobb,et al.  Interglacial Hydroclimate in the Tropical West Pacific Through the Late Pleistocene , 2012, Science.

[71]  B. Linsley.  Oxygen-isotope record of sea level and climate variations in the Sulu Sea over the past 150,000 years , 1996, Nature.

[72]  Gavin A. Schmidt,et al.  Forward modeling of carbonate proxy data from planktonic foraminifera using oxygen isotope tracers in a global ocean model , 1999 .

[73]  G. Leduc,et al.  More humid interglacials in Ecuador during the past 500 kyr linked to latitudinal shifts of the equatorial front and the Intertropical Convergence Zone in the eastern tropical Pacific , 2010 .

[74]  Y. Rosenthal,et al.  Orbital and suborbital climate variability in the Sulu Sea, western tropical Pacific , 2003 .

[75]  R. Fairbanks.  A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation , 1989, Nature.

[76]  A palynological and palaeoclimatological record from the southern Philippines since the Last Glacial Maximum , 2011 .

[77]  G. Leduc,et al.  Moisture transport across Central America as a positive feedback on abrupt climatic changes , 2007, Nature.

[78]  J. Moerman,et al.  Diurnal to interannual rainfall δ18O variations in northern Borneo driven by regional hydrology , 2013 .

[79]  Tapio Schneider,et al.  Migrations and dynamics of the intertropical convergence zone , 2014, Nature.