younger dryas a data to model comparison to constrain the strength of the overturning circulation 1 the university of victoria earth system climate model uvic escm is used to compare simulated time series of radiocarbon during the younger dryas yd with paleoceanographic records i find that only a complete shut down and recovery of the atlantic meridional overturning circulation amoc can simulate both the rise in atmospheric co2 concentrations seen in ice core records and the peak and subsequent decrease in atmospheric 14c comparable to the peak recorded in the varved sediments of the cariaco basin simulated radiocarbon profiles in the western north atlantic match well with data from deep sea corals at the beginning of the yd whereas planktonic benthic foraminifera records match best with a transient state during the rapid recovery of the amoc the steepness of the increase in atmospheric 14c at 12 9 ka cal could not be simulated with oceanic circulation changes only because the response time of the climate system is too slow

the silence of the layers archaeological site visibility in the pleistocene holocene transition at the ebro basin abstract the ebro basin constitutes one of the most representative territories in sw europe for the study of prehistoric societies during the pleistocene holocene transition the correlation of palaeoenvironmental and geomorphological proxies obtained from sedimentary records with chronologically well constrained reference archaeological sites has allowed defining this time frame precisely such that three main pilot areas haven been broadly depicted the alavese region the pre pyrenees and the bajo aragon overall the human imprint in the ebro basin was rare during the upper palaeolithic but more visible from the upper magdalenian 14500 13500 cal bp to neolithic times up to 5500 cal bp local environmental resources were continuously managed by the prehistoric communities in the different areas of study in fact the ebro basin acted during those millennia as a whole developing the same cultural trends industrial techniques and settlement patterns in parallel throughout the territory however some gaps exist in the 14c frequency curve scdpd curve this is partially related to prehistoric sites in particular lithologies and geological structures that could have partly been lost by erosional processes especially during the early holocene in addition this gap also parallels the reconstructed climate trend for the pre pyrenean and the bajo aragon areas which are defined by high frequencies of xerophilous flora until ca 9500 cal bp suggesting that continental climate features could have hampered the presence of well established human communities in inland regions the interdisciplinary research archaeology geomorphology and palaeoclimatology discussed in this paper offers clues to understand the existence of fills and gaps in the archaeological record of the ebro basin and can be applied in other territories with similar geographic and climate patterns

dansgaard oeschger and heinrich event imprints in alboran sea paleotemperatures past sea surface temperature sst evolution in the alboran sea western mediterranean during the last 50 000 years has been inferred from the study of c37 alkenones in international marine global change studies md952043 core this record has a time resolution of 200 years allowing the study of millennial scale and even shorter climatic changes the observed sst curve displays characteristic sequences of extremely rapid warming and cooling events along the glacial period comparison of this alboran record with 18o from greenland ice greenland ice sheet project 2 core shows a strong parallelism between these sst oscillations and the dansgaard oeschger events five prominent cooling episodes standing out in the sst profile are accompanied by an anomalous high abundance of neogloboquadrina pachyderma sinistral which is confined to the duration of these cold intervals these features and the isotopic record reflect drastic changes in the surface hydrography of the alboran sea in association with heinrich events hl 5

a phase altimetric simulator studying the sensitivity of earth reflected gnss signals to ocean topography this paper presents a simulation study on global navigation satellite system gnss reflections focusing on a phase altimetric method for ocean topography retrieval it examines carrier phase residuals of earth reflected gnss signals in preparation for the gnss reflectometry radio occultation and scatterometry experiment aboard the international space station geros iss the residuals sensitivity to ocean topography maximum of 2 m amplitude variation of global sea level is shown a trigonometric approach to determine the specular reflection point is proposed reflection events are simulated assuming different low earth orbit receivers and gnss type transmitters suitable events for phase altimetry are assumed between 5 and 30 elevation lasting between 10 and 15 min with ground tracks length of 3000 km typical along track footprints 1 s integration time have a length of about 5 km within the assumed elevation range the coherent footprint ellipse has a major axis between 1 and 6 km a master slave sampling is proposed to approximate large scale delay and doppler variations of the reflected signal slave channel relative to the direct signal master channel slave residuals of an example event are simulated to retrieve a small scale phase delay for ocean topography inversion the signal to noise ratio restricts the quality of the topography results height precision on sub decimeter level for 30 db snr is degraded up to a meter level for 20 db snr ionosphere free linear combination allows keeping the precision level troposphere refraction degrades precision particularly at the low elevation limit precision improves toward higher elevations the tolerance to ocean roughness decreases in the same way

epipalaeolithic assemblages in the western ebro basin spain the difficult identification of cultural entities abstract in this paper we analyse the transition late palaeolithic mesolithic in a restricted northern area into the ebro basin from alava to huesca provinces where this phase is still not well established between the end of the allerod and the start of the boreal the lithic assemblages are based on microlaminar industries with a predominance of backed pieces related to the magdalenian tradition despite this common microlaminar tradition some internal differences suggest the possibility of evolution in time and perhaps in space in order to develop an internal classification in the studied area we analyse some backed types and especially the chronological and regional relationship among the different industries tested

sea surface topography retrieved from gnss reflectometry phase data of the geohalo flight mission sea surface topography observations are deduced from an airborne reflectometry experiment a gnss global navigation satellite system receiver dedicated for reflectometry was set up aboard the german halo high altitude long range research aircraft flights were conducted over the mediterranean sea about 3500 m above sea level a signal path model divided into large and small scale contributions is used for phase altimetry the results depict geoid undulations and resolve anomalies of the sea surface topography for the whole experiment 65 tracks over the mediterranean sea are retrieved and compared with a topography model tracks differ between right handed and left handed circular polarization the difference however is not significant for this study precision and spatial resolution decrease disproportionately at low elevations eight tracks with centimeter precision are obtained between 11 and 33 of elevation at higher elevation angles the number of tracks is significantly reduced due to surface roughness in future such retrievals could contribute to ocean eddy detection

retrieval of significant wave height and mean sea surface level using the gnss r interference pattern technique results from a three month field campaign since 1993 when the european space agency esa proposed the use of global navigation satellite systems reflected signals for sea mesoscale altimetry a wide range of applications have appeared this paper focuses on the retrieval of significant wave height swh and the mean sea surface level mssl from a ground based experiment using the interference pattern technique ipt two different observables on the ipt are analyzed the oscillation frequency and the angle where coherency is lost the point where coherency in the reflection process is lost can be related to the rayleigh criterion for smooth surfaces and helps to determine the swh spectral analysis on the interference pattern helps to determine the mssl a three month field campaign was performed on the pont del petroli pier badalona spain to see how the reflected gnss signals were affected by coastal sea state and check previous assumptions results from this field experiment are shown confirming that the swh can be retrieved with accuracy of 6 cm and the mssl with 4 cm estimations of both parameters are obtained every 30 min approximately

comparison of oxygen isotope records from the gisp2 and grip greenland ice cores recent results1 2 from the greenland ice core project grip summit ice core suggest that the climate in greenland has been remarkably stable during the holocene but was extremely unstable for the time period represented by the rest of the core spanning the last two glaciations and the intervening eemian inter glacial here we present the complete oxygen isotope record for the greenland ice sheet project 2 gisp2 core drilled 28 km west of the grip core we observe large rapid climate fluctuations throughout the last glacial period which closely match those reported for the grip core however in the bottom 10 of the cores spanning the eemian interglacial and the previous glacia tion there are significant differences between the two records it is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores considerable further work will be necessary to evaluate the likelihood of this and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores

climate variability in the spanish pyrenees during the last 30 000 yr revealed by the el portalet sequence abstract palynological sedimentological and stable isotopic analyses of carbonates and organic matter performed on the el portalet sequence 1802 m a s l 42 48 00 n 0 23 52 w reflect the paleoclimatic evolution and vegetation history in the central western spanish pyrenees over the last 30 000 yr and provide a high resolution record for the late glacial period our results confirm previous observations that deglaciation occurred earlier in the pyrenees than in northern european and alpine sites and point to a glacial readvance from 22 500 to 18 000 cal yr bp coinciding with the global last glacial maximum the patterns shown by the new high resolution pollen data from this continental sequence chronologically constrained by 13 ams 14c dates seem to correlate with the rapid climate changes recorded in greenland ice cores during the last glacial interglacial transition abrupt events observed in northern latitudes heinrich events 3 to 1 oldest and older dryas stades intra allerod cold period and 8200 cal yr bp event were also identified for the first time in a lacustrine sequence from the central western pyrenees as cold and arid periods the coherent response of the vegetation and the lake system to abrupt climate changes implies an efficient translation of climate variability from the north atlantic to mid latitudes

a 135 000 year vostok specmap common temporal framework the object of the present study is to introduce a means of comparing the vostok and marine chronologies our strategy has been to use the 18o of atmospheric o2 denoted 18oatm from the vostok ice core as a proxy for the 18o of seawater denoted 18osw our underlying premise in using 18oatm as a proxy for 18osw is that past variations in 18osw an indicator of continental ice volume have been transmitted to the atmospheric o2 reservoir by photosynthesizing organisms in the surface waters of the world s oceans we compare our record of 18oatm to the 18osw record which has been developed from studies of the isotopic composition of biogenic calcite 18oforam in deep sea cores we have tied our 18oatm record from vostok to the specmap timescale throughout the last 135 kyr by correlating 18oatm with a 18osw record from v19 30 results of the correlation indicate that 77 of the variance is shared between these two records we observed differences between the 18oatm and the 18osw records during the coldest periods which indicate that there have been subtle changes in the factors which regulate 18oatm other than 18osw our use of 18oatm as a proxy for 18osw must therefore be considered tentative especially during these periods by correlating 18oatm with 18osw we provide a common temporal framework for comparing phase relationships between atmospheric records from ice cores and oceanographic records constructed from deep sea cores our correlated age depth relation for the vostok core should not be considered an absolute vostok timescale we consider it to be the preferred timescale for comparing vostok climate records with marine climate records which have been placed on the specmap timescale we have examined the fidelity of this common temporal framework by comparing sea surface temperature sst records from sediment cores with an antarctic temperature record from the vostok ice core we have demonstrated that when the southern ocean sst and antarctic temperature records are compared on this common temporal framework they show a high degree of similarity we interpret this result as supporting our use of the common temporal framework for comparing other climate records from the vostok ice core with any climate record that has been correlated into the specmap chronology

landscape resources and people during the mesolithic and neolithic times in ne iberia the arba de biel basin abstract the upper arba de biel constitutes a small valley in north eastern spain where a detailed study of five archaeological sites pena 14 legunova rambla valcervera and paco pons has been performed defining the recurrent prehistoric occupation from the late magdalenian until the chalcolithic the aim of this study focuses on exploring the main drivers of long term human persistence on a particular humid shelter located in the pre pyrenean area the combination of a multiproxy dataset evidenced by the detailed synthesis of lithic tools and pottery faunal remains pollen and charcoal assemblages has been integrated with a gis approach and a regional cultural and palaeoenvironmental contextualization after an occupation gap that coincides with the second half of the younger dryas and the first holocene millennia synchronous to other archaeological records found in ne iberia the arba de biel valley was recurrently visited by small hunter gatherer groups along the mesolithic and by herders during the neolithic these people profited this territory independently of environmental changes because the easy access to a wide spectre of economic resources flint nodules diverse vegetation supplies varied preys etc in a heterogeneous mosaic type landscape the valley main habitation spots pena 14 legunova rambla and valcervera could have been occupied at the same time by small groups that did not interfere each other the use of the fifth rockshelter paco pons seems to be related to the exploitation of copper mineral outcrops in the neolithic and for metallurgical activities during the chalcolithic these last prehistoric visits to the valley reflect a notable shift in the human employment of the shelters they cease to be living points to be used as funerary deposits

chronostratigraphy in karst records from the epipaleolithic to the mid early neolithic c 13 0 6 0 cal ka bp in the catalan coastal ranges of ne iberia environmental changes sedimentary processes and human activity abstract the stratigraphic sedimentary and palaeoenvironmental features reflected in cavities in the catalan coastal ranges of ne iberia can sadurni and guineu caves characterize the periods of pronounced climatic and human complexity that occurred c 13 0 6 0 cal ka bp this includes the stages of the younger dryas and mid early holocene the latter being one of the periods of so called rapid climatic changes rccs these caves like others in mediterranean contexts are the result of an old duct originating in the saturated zone of the karst system and open to the outside recording a succession of different detrital and anthropic episodes of the epipaleolithic mesolithic and neolithic communities from this study it can be seen that paleoclimatic events do not always present clear signals in the karst records especially c 12 7 7 4 cal ka bp corresponding to the epipaleolithic and mesolithic it is characterized by a stratigraphic discontinuity in which there are phases with predominantly detrital sedimentation alternating with hiatus intervals detrital sedimentation formed by fine material colluvium with gravitational movements or solifluction processes in fresh and humid conditions it appears in the following chronological intervals 12 7 12 2 cal ka bp 11 5 11 1 10 7 10 4 cal ka bp and 8 2 8 0 cal ka bp less humid hiatus phases are represented in the rest of the sequence up to c 7 4 cal ka bp from the sedimentary point of view these stages of hiatus are indicative of phases of stability or lack of episodes with seasonal contrasts a fact that would cause interruptions to detrital deposition in the interior of the caves in contrast in the period c 7 4 to 6 0 cal ka bp attributed to the middle and early neolithic there is a certain stratigraphic continuity from the sedimentary point of view it is distinguished by a variability of processes that responds to accumulative episodes of short duration characteristic of morphogenesis of the slopes in an arid mediterranean environment identified in our records as rccs c 7 4 7 2 cal ka bp cardial neolithic c 6 8 6 3 cal ka bp early postcardial middle neolithic and c 6 2 5 7 cal ka bp late postcardial middle neolithic alternating with episodes of stability more humid and coinciding with a better sedimentary record of the pastoral activity in the cavities during epicardial and late cardial neolithic c 7 1 6 7 cal ka bp and postcardial middle neolithic c 6 6 5 9 cal ka bp it is during this period that holocene climate variability has better resolution in caves in the catalan coastal ranges of ne iberia

detection of arctic ocean tides using interferometric gnss r signals 1 this paper evaluates the usage of reflected gps signals for earth observations to study changes of sea level and sea ice in remote sensing in a coastal setup 670 m above disko bay greenland signals with different carriers l1 and l2 were recorded a method is presented that analyses the interferometric phase between the reflected and the direct signals and derives the height of the reflecting surface the analysis includes a ray tracing and an estimation of signal coherence it is shown that coherent reflections are related to sea ice coverage absolute heights are derived with a time interval of 30 min the altimetric results show semidiurnal tides that are validated using the aodtm 5 tide model the residual height has a mean of 9 7 cm for l1 and 22 9 cm for l2 the dispersion is not significant but a significant tropospheric bias is detected with an error of up to 20 cm

carrier phase delay altimetry with gps reflection occultation interferometry from low earth orbiters 1 gps signals reflected off the surface of the earth can be detected by receivers aboard occulting low earth orbiters leos in this work carrier phase interferometry between the reflected and direct occultation signals is performed to infer its relative delay at centimetric error our analysis shows that submeter sensitivity on the surface heights can formally be reached with this technique the potential applications to polar ice altimetry are discussed

can we measure snow depth with gps receivers 1 snow is an important component of the climate system and a critical storage component in the hydrologic cycle however in situ observations of snow distribution are sparse and remotely sensed products are imprecise and only available at a coarse spatial scale gps geodesists have long recognized that snow can affect a gps signal but it has not been shown that a gps receiver placed in a standard geodetic orientation can be used to measure snow depth in this paper it is shown that changes in snow depth can be clearly tracked in the corresponding multipath modulation of the gps signal results for two spring 2009 snowstorms in colorado show strong agreement between gps snow depth estimates field measurements and nearby ultrasonic snow depth sensors because there are hundreds of geodetic gps receivers operating in snowy regions of the u s it is possible that gps receivers installed for plate deformation studies surveying and weather monitoring could be used to also estimate snow depth

the timing of postglacial coastal adaptations in eastern iberia a bayesian chronological model for the el collado shell midden oliva valencia spain abstract el collado is an open air site containing evidence of 14 burials and a shell midden archaeological deposit with different phases of human occupation dated to the early holocene previous studies have produced 14 radiocarbon dates using bone collagen samples from human burials however no attempt has been made to date the stratigraphic sequence to address the formation time of the shell midden and establish a chrono stratigraphic framework for the study of bio archaeological and cultural assemblages we critically evaluate the available radiocarbon record of the site and present 6 new ams radiocarbon dates on ungulate bones with anthropic fractures and bivalves from the three major stratigraphic horizons then we integrate our results with previously published ams radiocarbon determinations on human samples into a chronological bayesian model constraining the radiocarbon distributions with prior information about the samples stratigraphic provenance finally we correlate the results of the chronological model with the regional archaeological sequence and the available data on coastal evolution at regional and local scales the vertical distribution of the radiocarbon dates makes evident some stratigraphic disturbance caused by the repeated presence of pit graves agricultural activities and low stratigraphic control of the excavation process however once the problematic determinations are identified as outliers the remaining radiocarbon dates grouped according the major stratigraphic divisions and the calibrated distributions modelled constrained the resulting bayesian phase model reveal high agreement index ac 103 the shell midden formation took place from the bottom of the sequence spanning 1022 1965 calibrated years ci 95 4 the occupations documented at phase 1 level iv are dated to the early holocene 9828 9551 cal bp the phase 2 level ii encompass radiocarbon evidence of both burial and occupational activities dated to 9437 to 8477 cal bp spanning 779 985 calibrated years ci 95 4 finally the phase 3 level i records late mesolithic occupations deposited between 8509 and 8391 cal bp for the start boundary and 8499 8060 cal bp for the end boundary ci 95 4 there are no individual radiocarbon dates during or postdating the chronological span of the 8 2 ka climatic event 8300 8140 cal bp

middle palaeolithic refugium or archaeological misconception a new u series and radiocarbon chronology of abric agut capellades spain new u series and c14 ams dates are provided for the abric agut capellades barcelona spain this site was previously considered to be of middle palaeolithic age according to the characteristics of the lithic assemblage in addition human teeth were uncovered and attributed to neandertals however radiometric dating clearly indicates a late pleistocene early holocene age

improved gnss r ocean surface altimetry with cygnss in the seas of indonesia ocean surface altimetry with gnss reflectometry gnss r has the potential to improve the observation and retrieval of mesoscale ocean current flows by increasing the spatial density of ocean surface observations the leading challenges in current gnss r altimetry investigations include precise delay retracking correction of ionospheric effects and spacecraft receiver positioning here we present improved methods to account for these challenges a reflection model based approach is presented for delay retracking that uses simulated delay doppler maps ddms to retrieve the specular delay from measured ddms global ionosphere maps are used to estimate the group delay effect along the direct and reflection paths precise orbit determination techniques are used to improve estimates of the receiving spacecraft position and reduce systematic intersatellite biases we analyze altimetric height retrievals from two cases strongly coherent or diffuse reflections we study the residual systematic error signals with a focus on understanding the errors identified above the strong coherent observations have narrow symmetric delay waveforms and provide higher than average signal to noise ratio the ddms of diffuse observations originate from relatively rough ocean surfaces and have the characteristic horse shoe shape only measurements from the ocean and seas surrounding indonesia are considered as this area provides a significant number of strongly coherent reflections more than 50 000 single point observations and week long averaged results are presented to quantify the noise and systematic characteristics of the retrieved surface heights

first spaceborne phase altimetry over sea ice using techdemosat 1 gnss r signals a track of sea ice reflected global navigation satellite system gnss signal collected by the techdemosat 1 mission is processed to perform phase altimetry over sea ice high precision carrier phase measurements are extracted from coherent gnss reflections at a high angle of elevation 57 the altimetric results show good consistency with a mean sea surface mss model and the root mean square difference is 4 7 cm with an along track sampling distance of 140 m and a spatial resolution of 400 m the difference observed between the altimetric results and the mss shows good correlation with the colocated sea ice thickness data from soil moisture and ocean salinity this is consistent with the reflecting surface aligned with the bottom of the ice water interface due to the penetration of the gnss signal into the sea ice therefore these high precision altimetric results have potential to be used for determination of sea ice thickness

aspects of the structural evolution of the lusitanian basin in portugal and the shelf and slope area offshore portugal abstract the study provides a regional seismic interpretation and mapping of the mesozoic and cenozoic succession of the lusitanian basin and the shelf and slope area off portugal the seismic study is compared with previous studies of the lusitanian basin from the late triassic to the cretaceous the study area experienced four rift phases and intermittent periods of tectonic quiescence the triassic rifting was concentrated in the central part of the lusitanian basin and in the southernmost part of the study area both as symmetrical grabens and half grabens the evolution of half grabens was particularly prominent in the south the triassic fault controlled subsidence ceased during the latest late triassic and was succeeded by regional subsidence during the early early jurassic hettangian when deposition of evaporites took place a second rift phase was initiated in the early jurassic most likely during the sinemurian pliensbachian this resulted in minor salt movements along the most prominent faults the second phase was concentrated to the area south of the nazare fault zone and resulted here in the accumulation of a thick sinemurian callovian succession following a major hiatus probably as a result of the opening of the central atlantic resumed deposition occurred during the late jurassic evidence for late jurassic fault controlled subsidence is widespread over the whole basin the pattern of late jurassic subsidence appears to change across the nazare fault zone north of the nazare fault fault controlled subsidence occurred mainly along nnw sse trending faults and to the south of this fault zone a nne ssw fault pattern seems to dominate the oxfordian rift phase is testified in onlapping of the oxfordian succession on salt pillows which formed in association with fault activity the fourth and final rift phase was in the latest late jurassic or earliest early cretaceous the jurassic extensional tectonism resulted in triggering of salt movement and the development of salt structures along fault zones however only salt pillow development can be demonstrated the extensional tectonics ceased during the early cretaceous during most of the cretaceous regional subsidence occurred resulting in the deposition of a uniform lower and upper cretaceous succession marked inversion of former normal faults particularly along ne sw trending faults and development of salt diapirs occurred during the middle miocene probably followed by tectonic pulses during the late miocene to present the inversion was most prominent in the central and southern parts of the study area in between these two areas affected by structural inversion fault controlled subsidence resulted in the formation of the cenozoic lower tagus basin northwest of the nazare fault zone the effect of the compressional tectonic regime quickly dies out and extensional tectonic environment seems to have prevailed the miocene compressional stress was mainly oriented nw se shifting to more n s in the southern part

variability of the western mediterranean sea surface temperature during the last 25 000 years and its connection with the northern hemisphere climatic changes sea surface temperature sst profiles over the last 25 kyr derived from alkenone measurements are studied in four cores from a w e latitudinal transect encompassing the gulf of cadiz atlantic ocean the alboran sea and the southern tyrrhenian sea western mediterranean the results document the sensitivity of the mediterranean region to the short climatic changes of the north atlantic ocean particularly those involving the latitudinal position of the polar front the amplitude of the sst oscillations increases toward the tyrrhenian sea indicating an amplification effect of the atlantic signal by the climatic regime of the mediterranean region all studied cores show a shorter cooling phase 700 years for the younger dryas yd than that observed in the north atlantic region 1200 years this time diachroneity is related to an intra yd climatic change documented in the european continent minor oscillations in the southward displacement of the north atlantic polar front may also have driven this early warming in the studied area during the holocene a regional diachroneity propagating west to east is observed for the sst maxima 11 5 10 2 kyr b p in the gulf of cadiz 10 9 kyr b p in the alboran sea and 8 9 8 4 kyr b p in the thyrrenian sea a general cooling trend from these sst maxima to present day is observed during this stage which is marked by short cooling oscillations with a periodicity of 730 40 years and its harmonics

global ocean altimetry with gnss reflections from techdemosat 1 techdemosat 1 tds 1 is an experimental global navigation satellite system reflections gnss r satellite launched in 2014 the gnss r receiver onboard performs real time navigation and generates delay doppler correlation maps for earth reflected global positioning system gps l1 c a ranging signals this paper investigates the performance of the tds 1 data for ocean surface altimetry retrievals the analysis includes consideration of the transmitter and receiver orbits time tag corrections models for ionospheric and tropospheric delays zenith to nadir antenna baseline offsets ocean and solid earth tides and a comparison with mean sea surface topography an error budget is compiled to account for each error source and compared with the experimentally derived surface height retrievals by analyzing data sets covering global ocean surfaces over 60 latitude the current performance of spaceborne gnss r altimetry with the tds 1 data set is experimentally established in comparison with the mean sea surface topography the surface height residuals are found to be 6 4 m 1 sigma with a 1 s integration time a discussion of the factors limiting this performance is presented with implications for future gnss r altimetry missions designed for the observation of mesoscale ocean circulation

a high resolution absolute dated late pleistocene monsoon record from hulu cave china oxygen isotope records of five stalagmites from hulu cave near nanjing bear a remarkable resemblance to oxygen isotope records from greenland ice cores suggesting that east asian monsoon intensity changed in concert with greenland temperature between 11 000 and 75 000 years before the present yr b p between 11 000 and 30 000 yr b p the timing of changes in the monsoon as established with 230th dates generally agrees with the timing of temperature changes from the greenland ice sheet project two gisp2 core which supports gisp2 s chronology in this interval our record links north atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer east asian monsoon originates

isotope evidence for the use of marine resources in the eastern iberian mesolithic there are relatively few coastal mesolithic sites in the iberian mediterranean region probably due to a number of factors including sea level changes and the disappearance of sites due to agriculture and urbanisation however recent excavations have uncovered inland sites that have marine faunal remains i e molluscs and fish and lithics from the coastal area which both indicate interactions between the coast and the upland valleys these inland sites are located at a distance of 30 50 km from today s coastline and are at altitudes higher than 1000 m we report on additional information on the links between the coast and these inland sites through the use of dietary isotope analysis carbon and nitrogen stable isotope analysis of collagen extracted from human and faunal remains at the sites of coves de santa maira penya del comptador and cingle del mas nou the results indicate that mesolithic diet in this region was largely based on c3 terrestrial resources but there was measurable evidence of low level consumption of marine resources at both coastal and inland sites

the padul mammoth finds on the southernmost record of mammuthus primigenius in europe and its southern spread during the late pleistocene abstract fossil remains of at least four mature to old mature male individuals of mammuthus primigenius have been discovered in a peat bog of late pleistocene age situated near to the town of padul in the granada basin southern spain radiocarbon dates indicate the presence of woolly mammoth in southern spain between 35 8 and 25 7 ka bp 40 4 30 6 cal ka bp a time span corresponding with the later part of mis 3 the padul mammoths did not differ morphometrically from individuals of contemporaneous populations of other european regions but represent the westernmost portion of an extended and continuous holarctic belt of mammoth distribution the area immediately northwest of the pyrenees including a slender belt of dry land along the coast of the bay of biscay is considered the immigration route of m primigenius into the iberian peninsula the southernmost extent of iberian woolly mammoths correlates with periods of particularly dry and cold climatic conditions where they are documented in terrestrial and marine sediment sequences of the region the southern expansion of m primigenius during the late pleistocene extended to similar latitudes in europe asia and north america paralleling the distribution of suitable steppe or tundra steppe like environments the woolly mammoth s southernmost advances were limited by the vegetational character of corresponding landscapes by the configuration of marine shore lines and high mountain chains and by the extension of semideserts and deserts phases of mammoth dispersal into the iberian and italian peninsulas during the later part of mis 3 and early mis 2 can be roughly correlated with the southern distribution of the species in the eastern palaearctic along the eastern coast of the pacific ocean the topography and glaciation of the rocky mountains range prevented a similar dispersal of woolly mammoths into western north america the expansion of late pleistocene m primigenius within the inner continental areas of eurasia and north america differs chronologically from those at the continental margins

the paris ocean altimeter in orbit demonstrator mesoscale ocean altimetry remains a challenge in satellite remote sensing conventional nadir looking radar altimeters can make observations only along the satellite ground track and many of them are needed to sample the sea surface at the required spatial and temporal resolutions the passive reflectometry and interferometry system paris using global navigation satellite systems gnss reflected signals was proposed as a means to perform ocean altimetry along several tracks simultaneously spread over a wide swath the bandwidth limitation of the gnss signals and the large ionospheric delay at l band are however issues which deserve careful attention in the design and performance of a paris ocean altimeter this paper describes such an instrument specially conceived to fully exploit the gnss signals for best altimetric performance and to provide multifrequency observations to correct for the ionospheric delay furthermore an in orbit demonstration mission that would prove the expected altimetric accuracy suited for mesoscale ocean science is proposed

human responses to younger dryas in the ebro valley and mediterranean watershed eastern spain the archaeological and chronological records of the ebro river valley and the mediterranean watershed eastern spain are examined to evaluate the effects of the younger dryas greenland stadial 1 on the foragers of an area between 36