late quaternary climate change from δ18o records of multiple species of planktonic foraminifera high resolution records from the anoxic cariaco basin venezuela seasonal trade wind induced upwelling along the southern margin of the caribbean sea occurs in response to the annual migration of the intertropical convergence zone laminated high deposition rate sediments of the cariaco basin a small anoxic basin on the venezuelan continental shelf clearly record large changes in the past intensity of this upwelling because sediments of the cariaco basin are largely unbioturbated they offer a natural opportunity to study the stable isotopic records of multiple planktonic foraminiferal taxa and to evaluate their sensitivity to both the modern hydrography and temporal changes in upwelling intensity and climate oxygen isotope data 18o from four dominant foraminiferal taxa are presented for the time period covering the last 28 kyr the 18o data from globigerina bulloides after correction for nonequilibrium precipitation are used as a monitor of sea surface conditions during the winter spring upwelling season the 18o data from white globigerinoides ruber are used as a measure of annual average conditions in the near surface while pink g ruber data are consistent with use as an index of endmember conditions during the summer fall nonupwelling season data from the deeper dwelling neogloboquadrina dutertrei yield information on conditions near the base of the local thermocline during the last glacial 18o data from g ruber and generally reduced interspecific differences indicate cooling of surface waters over the cariaco basin by up to 4 c this longer term cooling does not appear to be related to changes in upwelling intensity along the coast but may instead reflect more regional cooling of the larger caribbean superimposed on this pattern between 12 6 and 10 ka is a convergence of 18o data between g bulloides and n dutertrei implying much stronger upwelling during the last deglaciation this scenario is consistent with other evidence for high productivity at this time at 14 ka a sharp 18o depletion event observed in all taxa seems to have been produced by increased freshwater discharge to the southern caribbean suggesting either higher regional rainfall or the influence of glacial melting in the andes minimum 18o values of pink g ruber around 6 7 ka record warmer summer sea surface temperatures and or decreased salinity in the mid holocene

variations in mode of formation and temperature of oceanic deep waters over the past 125 000 years marked changes in the deep water temperature of the different oceanic basins during the past 125 kyr are revealed by a detailed comparison of the oxygen isotopic composition ofbenthicforaminiferafrom sediment cores taken from the norwegian sea and the pacific atlantic and southern oceans the last interglacial deep water temperatures were similar to the modern ones at the 5e 5d transition around 115 kyr bp the deep water temperatures dropped below approximately 0 c in the pacific and southern indian oceans in the atlantic ocean the deep water temperature dropped in 2 successive steps at 115 and 75ky bp the global ocean deep water temperatures were in the 0 to 1 c range for the whole of the last ice age isotope stages 4 2

modern distribution patterns of planktonic foraminifera in the south china sea and western pacific a new transfer technique to estimate regional sea surface temperatures abstract we present 30 new planktonic foraminiferal census data of surface sediment samples from the south china sea recovered between 630 and 2883 m water depth these new data together with the 131 earlier published data sets from the western pacific are used for calibrating the simmax 28 transfer function to estimate past sea surface temperatures this regional simmax method offers a slightly better understanding of the marginal sea conditions of the south china sea than the linear transfer function fp 12e which is based only on open ocean data however both methods are biased toward the tropical temperature regime because of the very limited data from temperate to subpolar regions the simmax formula was applied to sediment core 17940 from the northeastern south china sea with sedimentation rates of 20 80 cm ka results revealed nearly unchanged summer temperatures around 28 c for the last 30 ky while winter temperatures varied between 19 5 c in the last glacial maximum and 26 c during the holocene during termination 1a the winter estimates show a younger dryas cooling by 3 c subsequent to a temperature optimum of 24 c during the bolling allerod estimates of winter temperature differences between 0 and 100 m water depth document the seasonal variations in the thickness of the mixed layer and provide a new proxy for estimating past changes in the strength of the winter monsoon

a study of cleaning procedures used for foraminiferal mg ca paleothermometry the various cleaning steps required for preparation of foraminiferal samples for mg ca and sr ca analysis are evaluated for their relative importance and effects on measured elemental ratios it is shown that the removal of silicate contamination is the most important step for the measurement of mg ca ratios in an example bulk sample mg ca decreases from 10 5 to 2 5 mmol mol 1 during clay removal oxidation of organic material causes a lowering of sample mg ca in the order of 10 or approximately 1 c when converted to temperature use of dilute acid leaching to remove adsorbed contaminants causes partial dissolution of the sample carbonate and a corresponding decrease in mg ca reductive treatment also causes dissolution of the sample and a decrease in the mg ca ratio of up to 10 15 sample preparation for sr ca analysis does not require the same degree of rigor as is necessary for mg ca work the within run reproducibility of the method described here for g ruber in a core top sample from the arabian sea was 1 8 mean sample ratio was 4 72 mmol mol 1 when converted to temperature this becomes 28 0 2 c the equivalent result for sr ca was 0 5 mean ratio 1 44 mmol mol 1

oxygen isotopic composition of multiple species of planktonic foraminifera recorders of the modern photic zone temperature gradient abundances of 12 species of planktonic foraminifera collected in two plankton tows from the east tropical atlantic are compared to the chlorophyll content and the temperature of the sea water from which they were collected as expected from previous work in the tropics all dominant tropical species occur in greatest abundance within the photic zone many species occur in greatest abundances in the seasonal thermocline in association with the maximum chlorophyll concentration while a few algal symbiont bearing species occur in greatest abundance in the mixed layer the 18o measurements of planktonic foraminifera shells from core top sediment samples confirm the vertical stratification within the photic zone that is suggested by the relationship between hydrography and abundances found in the plankton tows and found in the statistical study by ravelo et al 1990 comparison between the measured 18o values of planktonic foraminifera with the predicted 18o profiles of the overlying water column at three core locations indicate that species abundances in the sediment record the seasonally integrated conditions of the photic zone and suggests that the abundance of a species in the sediment depends on whether the preferred ecological conditions of that species may be found within the photic zone of the overlying water column sometime during the year species which calcify below the photic zone have only trace relative abundances finally it appears that the total range of 18o values of the dominant species approximates the predicted annual 18o of calcite range in the upper 80 m of the water column

reevaluation of the oxygen isotopic composition of planktonic foraminifera experimental results and revised paleotemperature equations cultured planktonic foraminifera orbulina universa symbiotic and globigerina bulloides nonsymbiotic are used to reexamine temperature 18o relationships at 15 25 c relationships for both species can be described by linear equations equations for o universa grown under low light ll and high light hl share a slope of 4 80 0 21 c 1 with a hl ll offset of 0 33 due to symbiont photosynthetic activity the effect of co32 on o universa is 0 002 mol 1 kg 1 and is insensitive to temperature for g bulloides ontogenetic effects produce size related trends in temperature 18o whereby larger shells are enriched in 18o relative to smaller specimens the o universa temperature 18o relationships are more accurate than previously published equations for describing plankton tow data our equations do not explain planktonic core top data with the same precision but provide a good fit to benthic cibicidoides data below 10 c temperature 18o relationships for g bulloides provide good agreement with field data for this species from the northeast pacific

isotope calibrated greenland temperature record over marine isotope stage 3 and its relation to ch4 large temperature variations on millennial time scales in greenland characterised the last ice age abrupt warmings known as dansgaard oeschger do events can be traced in the 18oice record of greenland ice cores however it has been shown that 18oice is not a direct temperature proxy measurements of the isotopic composition of gases trapped in the ice can be used to calibrate the paleothermometer here we present a continuous temperature record based on high resolution 15n measurements and firn model studies it covers a sequence of 9 do events 9 17 during the time period from 38 to 64 kyr bp for which temperature changes of 8 to 15 c were estimated the difference between the modern and the glacial 18oice t relationship can be explained by a combination of source temperature changes and changes in the annual distribution of precipitation a detailed comparison of the temperature evolution with reconstructions of the atmospheric methane ch4 concentration shows that ch4 rises lag temperature increases at the onset of do events by 25 to 70 yr within data resolution the strong correlation between greenland temperature and ch4 on millennial and submillennial time scales suggests that variations on these time scales were probably of hemispheric extent

rapid changes of glacial climate simulated in a coupled climate model abrupt changes in climate termed dansgaard oeschger and heinrich events have punctuated the last glacial period approximately 100 10 kyr ago but not the holocene the past 10 kyr here we use an intermediate complexity climate model to investigate the stability of glacial climate and we find that only one mode of atlantic ocean circulation is stable a cold mode with deep water formation in the atlantic ocean south of iceland however a warm circulation mode similar to the present day atlantic ocean is only marginally unstable and temporary transitions to this warm mode can easily be triggered this leads to abrupt warm events in the model which share many characteristics of the observed dansgaard oeschger events for a large freshwater input such as a large release of icebergs the model s deep water formation is temporarily switched off causing no strong cooling in greenland but warming in antarctica as is observed for heinrich events our stability analysis provides an explanation why glacial climate is much more variable than holocene climate

mineralization and ore genesis of the qiaoxiahala fe cu au deposit in the northern margin of east junggar terrane central asian orogenic belt constraints from fluid inclusions and stable isotopes abstract the qiaoxiahala fe cu au deposit 1 44 mt ore 43 53 fe 0 55 2 21 cu and 0 13 2 4 g t au is located in the northern margin of east junggar terrane nw china the deposit is hosted in the upper part of the middle devonian beitashan formation mafic and felsic volcanic rocks and sedimentary interbeds and is spatially closely related to local fractures six hypogene hydrothermal stages have been identified including stage i early skarn stage ii late skarn stage iii magnetite mineralization stage iv magnetite pyrite mineralization stage v chalcopyrite mineralization and stage vi late veins these six stages include three major mineralization events as represented by the stage iii magnetite epidote k feldspar quartz calcite stage iv magnetite pyrite garnet quartz calcite and stage v chalcopyrite chlorite assemblages the stage iii magnetite mineralization fluids were likely of high temperature 354 386 c low medium salinity 9 9 14 7 wt nacl equiv mg fe rich and organic rich with lithostatic pressure of 1 3 1 5 kbar and corresponding depth of 4 3 4 8 km oxygen and hydrogen isotopes showed that the 18o rich 9 7 11 2 and d rich 26 3 fluids were possibly modified from the early carboniferous seawater interacting with the beitashan formation organic rich limestone or tuff in comparison the stage iv magnetite pyrite mineralization fluids were likely of medium high temperature 272 453 c low medium salinity 2 9 19 5 wt nacl equiv mg fe rich with pressure of 0 8 1 2 kbar and corresponding depth of 2 6 4 0 km the stage v chalcopyrite mineralization fluids were likely of low medium temperature 186 270 c low medium salinity 1 4 21 8 wt nacl equiv ca or na rich with pressure of 0 4 0 6 kbar and corresponding depth of 1 2 km hydrogen and oxygen isotopic compositions stage iv dwater 141 to 92 18owater 8 9 11 1 stage v dwater 104 18owater 7 2 suggest that the ore fluids were of connate marine origin furthermore stage iv 13cwater values 0 6 to 0 also indicate interactions between seawater and sedimentary wall rocks the negative sulfur isotopic compositions of chalcopyrite and pyrite 4 2 to 0 2 may demonstrate a biogenic sulfur source compared with the arc related iocg deposits in the central andean orogen the qiaoxiahala fe cu au deposit shares many common features in geology mineralization alteration and various sources of fluids indicating a possible iocg like mineralization style and potential to discover other late paleozoic arc related iocg deposits in east junggar

orbitally paced paleoproductivity variations in the timor sea and indonesian throughflow variability during the last 460 kyr 1 a high resolution 1 2 kyr multiproxy record from the timor sea in the easternmost indian ocean international marine global change images program core md01 2378 latitude 13 04 95 s longitude 121 47 27 e 1783 m water depth closely tracks changes in intermediate water ventilation and paleoproductivity over the last 460 kyr within one of the main outflow passages of the indonesian throughflow spectral analysis of five different flux based productivity proxies indicates spectral power concentrated in the 100 kyr glacial interglacial and the 23 kyr and 19 kyr precessional periods paleoproductivity maxima lead ice volume benthic 18o maxima by 20 to 40 1300 to 2600 years at the precession band the spectral differences in tropical paleoproductivity records from the pacific and indian oceans suggest that local processes wind and circulation patterns driven by insolation are dominant in driving productivity rather than large scale tropical features in the timor sea productivity fluctuations over the last 460 kyr were strongly influenced by monsoonal wind patterns offshore nw australia 23 and 19 kyr and were also modulated by sea level related variations in the intensity of the indonesian throughflow 100 kyr

evidence for indonesian throughflow slowdown during heinrich events 3 5 we present sea surface and upper thermocline temperature records 60 100 year temporal resolution spanning marine isotope stage 3 similar to 24 62 ka b p from international marine global change study core md01 2378 121 degrees 47 27 e and 13 degrees 04 95 s 1783 m water depth located in the outflow area of the indonesian throughflow within the timor sea stable isotopes and mg ca of the near surface dwelling planktonic foraminifer globigerinoides ruber white and the upper thermocline dwelling pulleniatina obliquiloculata reveal rapid changes in the thermal structure of the upper ocean during heinrich events thermocline warming and increased delta o 18 seawater p obliquiloculata record during heinrich events 3 4 and 5 reflect weakening of the relatively cool and fresh thermocline flow and reduced export of less saline water from the north pacific and indonesian seas to the tropical indian ocean three main factors influenced indonesian throughflow variability during marine isotope stage 3 1 global slowdown in thermohaline circulation during heinrich events triggered by northern hemisphere cooling 2 increased freshwater export from the java sea into the indonesian throughflow controlled by rising sea level from similar to 60 to 47 ka and 3 insolation related changes in the australasian monsoon with associated migration of hydrological fronts between indian ocean and indonesian throughflow derived water masses at similar to 46 40 ka

phase relationships between millennial scale events 64 000 24 000 years ago a core recovered on the iberian margin off southern portugal can be correlated with greenland ice cores using oxygen isotope variability in planktonic foraminifera which closely matches the ice core records of temperature over greenland our age model identifies the base of every interstadial between 64 000 and 24 000 years ago and uses the greenland ice core project grip timescale the oxygen isotope signal in benthic foraminifera on this grip based timescale is quite different from the planktonic record and resembles the temperature record over antarctica when this is synchronized with greenland using the record of methane in the atmospheric air in the polar ice cores we interpret the benthic record as indicating significant fluctuations in ice volume during millennial events and we suggest that antarctic temperature changed as a function of ice volume

progress in paleosalinity overview and presentation of a new approach this paper concerns the use of stable oxygen isotope ratios 18o and stable hydrogen isotope ratios 2h or d to derive paleosalinity first i evaluate the potential and limitations of existing methods based on 18o and d separately next i propose a new theoretical framework for the combined use of 18o and d to constrain the impact of the hydrological cycle on the surface waters and to thus characterize changes in surface water salinity this new method is accompanied by an error propagation exercise to demonstrate its limitations and areas of potential improvement a feasible strategy is outlined for achieving reconstructions of paleosalinity change with an uncertainty of 1 practical salinity unit or less with the newly proposed method especially in regions with high deuterium excess values

changes in the thermocline structure of the indonesian outflow during terminations i and ii we present centennial records of sea surface and upper thermocline temperatures in core md01 2378 from the timor sea which provide new insights into the variability of the indonesian outflow across the last two glacial terminations mg ca in globigerinoides ruber white s s indicates an overall increase of 3 2 degrees c in sea surface temperature sst over termination i following an early holocene plateau at 11 3 6 4 ka ssts cooled by 0 6 degrees c during the middle to late holocene 6 4 0 7 ka the early holocene warming occurred in phase with increasing northern hemisphere summer insolation coinciding with northward displacement of the intertropical convergence zone enhanced boreal summer monsoon and expansion of the indo pacific warm pool thermocline temperatures pulleniatina obliquiloculata mg ca gradually decreased from 24 5 to 21 5 degrees c since 10 3 ka reflecting intensification of a cool thermocline throughflow the vertical structure of the upper ocean in the timor sea evolved in similar fashion during the holocene and mis5e although the duration of sst plateaux differed 11 3 to 6 4 ka in termination i and from 129 to 119 ka in termination 11 which was probably due to the more intense northern hemisphere summer insolation during mis 5e during both terminations sst increased simultaneously in the southern high latitudes and the tropical eastern indian ocean suggesting virtually instantaneous atmospheric climate feedbacks between the high and low latitudes c 2008 elsevier b v all rights reserved

low latitude hydrological cycle and rapid climate changes during the last deglaciation sea surface temperature and oxygen isotopic records from two well dated indian ocean cores covering the last deglaciation show the occurrence of two periods of increased salinity along the route of warm surface water transport from the indian to the atlantic ocean one between 18 and 14 5 ka and the other during the younger dryas our results imply that during these periods salt accumulated in the tropical atlantic creating favorable conditions for an abrupt resumption of the thermohaline circulation and abrupt northern hemisphere warming furthermore we suggest that the observed pattern of millennial climate variability during the last glacial and deglaciation resulted from the interaction between the relatively slow rhythm of expansion and decay of the northern hemisphere ice sheets and el nino southern oscillation variability through changes in the position of the intertropical convergence zone this interaction generated an oscillator with millennial time response that operated at times of sufficient northern hemisphere ice sheets extent

fluid metasomatic genesis of stratiform skarn in the suoerkuduke cu mo deposit east junggar nw china abstract stratiform skarns associated with ore deposits are widespread in the north of east junggar particularly in the suoerkuduke cu mo deposit the suoerkuduke stratiform and stratoid skarns are hosted by devonian intermediate mafic volcanic and pyroclastic rocks mainly andesite andesitic porphyry and tuffaceous sandstone without carbonate or calcareous rocks the skarns consist of dominant andradite grossular epidote diopside hedenbergite and minor actinolite quartz magnetite and metallic sulfides the garnet and epidote composition especially fe 3 and al contents is largely a function of the bulk composition and physicochemical environment particularly f o 2 during crystallization such mineralogy indicates a relatively oxidizing environment and medium acidity of solution during skarnization the suoerkuduke skarns are distinct from typical contact metasomatic skarn in wall rock as no carbonate or calcareous rocks were found and differ in the distribution patterns of skarn zonation in that gradually weakened skarn zones are not quite symmetrically distributed on both sides of the alteration center a garnet skarn abundant remnants of andesite andesitic porphyry and tuffaceous sandstone in the weakened skarn zone indicate that the protolith of the skarn is andesite andesitic porphyry and tuffaceous sandstone magmatic water meteoric and seawater are involved in skarn alteration moyite and granitic porphyry are not coeval with skarn and their emplacement resulted in the hornfelization of wall rock instead of skarnization and themselves keep away from skarn alteration therefore there was probably a huge batholith supplying magmatic fluid for skarn formation mass balance estimates suggest that hydrothermal fluid must contribute a portion of ca and fe to ensure sufficient supply for skarn formation in the absence of local carbonate and calcareous rocks in conclusion the stratiform skarns in the suoerkuduke are products of intermediate mafic volcanic and pyroclastic rocks metasomatised by hydrothermal fluid that probably leached calcareous wall rock during ascent

calibration of mg ca thermometry in planktonic foraminifera from a sediment trap time series 1 paired mg ca and 18o measurements on planktonic foraminiferal species g ruber white g ruber pink g sacculifer g conglobatus g aequilateralis o universa n dutertrei p obliquiloculata g inflata g truncatulinoides g hirsuta and g crassaformis from a 6 year sediment trap time series in the sargasso sea were used to define the sensitivity of foraminiferal mg ca to calcification temperature habitat depths and calcification temperatures were estimated from comparison of 18o of foraminifera with equilibrium calcite based on historical temperature and salinity data when considered together mg ca mmol mol of all species except two show a significant r 0 93 relationship with temperature t c of the form mg ca 0 38 0 02 exp 0 090 0 003 t equivalent to a 9 0 0 3 change in mg ca for a 1 c change in temperature small differences exist in calibrations between species and between different size fractions of the same species o universa and g aequilateralis have higher mg ca than other species and in general data can be best described with the same temperature sensitivity for all species and pre exponential constants in the sequence o universa g aequilateralis g bulloides g ruber g sacculifer other species this approach gives an accuracy of 1 2 c in the estimation of calcification temperature the 9 sensitivity to temperature is similar to published studies from culture and core top calibrations but differences exist from some literature values of pre exponential constants different cleaning methodologies and artefacts of core top dissolution are probably implicated and perhaps environmental factors yet understood planktonic foraminiferal mg ca temperature estimates can be used for reconstructing surface temperatures and mixed and thermocline temperatures using g ruber pink g ruber white g sacculifer n dutertrei p obliquiloculata etc the existence of a single mg thermometry equation is valuable for extinct species although use of species specific equations will where statistically significant provide more accurate evaluation of mg ca paleotemperature

millennial scale trends in west pacific warm pool hydrology since the last glacial maximum models and palaeoclimate data suggest that the tropical pacific climate system plays a key part in the mechanisms underlying orbital scale and abrupt climate change atmospheric convection over the western tropical pacific is a major source of heat and moisture to extratropical regions and may therefore influence the global climate response to a variety of forcing factors the response of tropical pacific convection to changes in global climate boundary conditions abrupt climate changes and radiative forcing remains uncertain however here we present three absolutely dated oxygen isotope records from stalagmites in northern borneo that reflect changes in west pacific warm pool hydrology over the past 27 000 years our results suggest that convection over the western tropical pacific weakened 18 000 20 000 years ago as tropical pacific and antarctic temperatures began to rise during the early stages of deglaciation convective activity as inferred from oxygen isotopes reached a minimum during heinrich event 1 ref 10 when the atlantic meridional overturning circulation was weak pointing to feedbacks between the strength of the overturning circulation and tropical pacific hydrology there is no evidence of the younger dryas event in the stalagmite records however suggesting that different mechanisms operated during these two abrupt deglacial climate events during the holocene epoch convective activity appears to track changes in spring and autumn insolation highlighting the sensitivity of tropical pacific convection to external radiative forcing together these findings demonstrate that the tropical pacific hydrological cycle is sensitive to high latitude climate processes in both hemispheres as well as to external radiative forcing and that it may have a central role in abrupt climate change events

effect of h2o on liquidus relationships in mgo al2o3 sio2 at 30 kilobars dehydrated gels with compositions corresponding to mixtures of pyrope enstatite pyrope quartz and pyrope quartz corundum were sealed in platinum capsules and reacted in half inch piston cylinder apparatus at 30 kbar samples were pyrope composition with variable h2o and other compositions with 7 5 wt h2o highly aluminous metastable orthopyroxenes nucleated from and persisted in mixtures with compositions near pyrope there is no univariant fusion curve for pyrope h2o pyrope dissolves incongruently in h2o subsolidus and a trace of liquid is produced near 1000 c a univariant reaction pyrope forsterite vapor spinel liquid was located at 1150 20 c the liquidus for pyrope with excess h2o is at 1310 c orthopyroxenes coexisting with sio2 rich liquids contain 0 8 5 7 excess sio2 compared with mgsio3 al2o3 liquidus diagrams dry with 7 5 h2o and with excess h2o illustrate the effect of h2o on the liquidus relationships with increasing h2o the liquidus volume for opx expands greatly at

ore genesis and metallogenic model of qiaoxiahala fe cu au deposit in xinjiang the qiaoxiahala fe cu au deposit is similar to volcanic sedimentary fe deposits and skarn type fe cu au deposits its iron was derived from magma whereas its copper came mainly from intrusive hydrothermal solution and partly from basic volcanic wall rocks iron and copper were subjected to two stages of mineralization related respectively to volcanic sedimentary mineralization and subsequent hydrothermal superimposition and reformation during the process of magmatic eruption and effusion iron was concentrated and deposited in sea water to form stratoid magnetite ore bodies with the subsequent fault activities and the emplacement of basic intrusions copper bearing hydrothermal solution moved upward and formed chalcopyrite multiple fault activities led to the enrichment of existent iron and copper and the formation of disseminated and massive ore bodies the southeastern margin of junggar seems to be favorable for further prospecting

possible evidence for wet heinrich phases in tropical ne australia the lynch s crater deposit unarguably one of the most significant paleoclimatological discoveries of the last two decades has been that of abrupt climate events dansgaard oeschger cycles and heinrich events most evidence for these events has originated from the high latitude northern hemisphere with few records documenting the response of the low latitude southern hemisphere here we present new data from lynch s crater a unique terrestrial record from ne australia that may show evidence for southward propagations of the intertropical convergence zone itcz during abrupt climate perturbations as a result of alteration of the low latitude air masses proxies for precipitation wetness indicate enhanced rainfall in the region during heinrich events h events 1 3 and the 8 2 ka northern hemisphere cold event a fully coupled atmosphere ocean climate model simulating a 1 sv freshwater influx to the north atlantic ocean produces a scenario which agrees with the climate changes shown by the lynch s crater record the model shows precipitation anomalies that include a southward migration of the itcz and a zonal shift in mid latitude storm tracks over the southern hemisphere equatorial region these data indicate large scale shifts of the austral summer itcz position that is known to control monsoonal precipitation in ne australia this terrestrial record from australia may demonstrate the involvement of the tropical western pacific ocean in itcz migrations during abrupt climate events of the last glacial period defining such past migrations offers insight into the importance and role of the equatorial region in global climate dynamics

dominant northern hemisphere climate control over millennial scale glacial sea level variability abstract based on a radiocarbon and paleomagnetically dated sediment record from the northern red sea and the exceptional sensitivity of the regional changes in the oxygen isotope composition of sea water to the sea level dependent water exchange with the indian ocean we provide a new global sea level reconstruction spanning the last glacial period the sea level record has been extracted from the temperature corrected benthic stable oxygen isotopes using coral based sea level data as constraints for the sea level oxygen isotope relationship although the general features of this millennial scale sea level records have strong similarities to the rather symmetric and gradual southern hemisphere climate patterns we observe in constrast to previous findings pronounced sea level rises of up to 25 m to generally correspond with northern hemisphere warmings as recorded in greenland ice core interstadial intervals whereas sea level lowstands mostly occur during cold phases corroborated by climber 2 model results the close connection of millennial scale sea level changes to northern hemisphere temperature variations indicates a primary climatic control on the mass balance of the major northern hemisphere ice sheets and does not require a considerable antarctic contribution

east asian monsoon forcing of suborbital variability in the sulu sea during marine isotope stage 3 link to northern hemisphere climate 1 we have generated a new high resolution record of variations in planktonic foraminiferal oxygen isotopes 18o and mg ca from a sediment core images 97 2141 in the sulu sea located in the philippine archipelago of western tropical pacific this record reveals distinct suborbital scale 18o changes most notably during marine isotope stage 3 mis3 30 000 to 60 000 years b p the amplitudes of these 18o fluctuations 0 4 to 0 7 exceed that which can be attributed to sea level changes and must be due to changes in sea surface conditions in the same interval variations in planktonic foraminifera mg ca suggest that suborbital surface ocean temperature variations of 1 to 1 5 c in the sulu sea were not in phase with 18o combined this evidence indicates that the mis3 millennial 18o events in the sulu sea were primarily the result of changes in surface water salinity which today is directly related to the east asian monsoon eam and its influence on the balance between surface water contributions from the south china sea and western pacific warm pool wpwp within dating uncertainties the mis3 sulu sea 18o suborbital variability indicates that times of fresher surface conditions in the sulu sea coincide with similar conditions in the wpwp stott et al 2002 and also with intensifications of the summer eam as recorded in the u th dated chinese hulu cave speleothem 18o record wang et al 2001 and thus by inference with interstadials in the greenland ice core records combined these results indicate that pronounced suborbital variability in the summer eam and intertropical convergence zone itcz during mis3 was tightly coupled with climate conditions in the northern high latitudes