potentially toxic elements ptes associated with asbestos chrysotile tremolite and actinolite in the calabria region italy abstract potentially toxic elements ptes hosted in asbestos elongate mineral particles is one of the factors that determines their toxic pathogenic effects this study quantifies and compares these elements in terms of major minor and trace element concentrations si mg ca al fe mn cr co ni cu zn be v as rb sb ba pb sr in various types of asbestos using micro x ray fluorescence xrf and inductively coupled plasma mass spectrometry icp ms in order to understand how they contribute to asbestos related diseases chrysotile tremolite asbestos and actinolite asbestos extracted from the gimigliano mount reventino unit calabria region southern italy were used for this study in the minerals analysed high concentrations of cr 171 ppm and be 2 9 ppm were found in tremolite asbestos and chrysotile respectively when calculating the pseudo total concentrations of trace elements in the samples the largest amounts were detected in tremolite asbestos followed by actinolite asbestos and chrysotile however since other metals such as mn and fe minor elements are known to induce toxicity and considering their input to the overall balance actinolite contained the largest amount of ptes and in this case chrysotile proved to be more toxic than tremolite asbestos furthermore the potential leaching of ptes released by chrysotile tremolite and actinolite asbestos containing rocks into the soil and water supply is also discussed since asbestos elongate mineral particles can be widespread in the environment i e air rocks soil water it is essential to quantify the toxic elements present in asbestos elongate mineral particles in order to prevent asbestos related diseases the knowledge obtained from this study will provide us with a better understanding of asbestos related lung cancer

deciphering the tectonic geodynamic context of the gem quality noble serpentine deposit formation combining microstructural chemical and micro raman analyses in palaeozoic olivine bearing marbles and serpentine hosting rocks pizzo tremogge margna unit austroalpine val malenco central alps italy abstract the gem quality noble serpentine of pizzo tremogge val malenco italy is included in palaeozoic olivine bearing marbles occurring in the margna unit central austroalpine domain a detailed inspection of serpentine samples reveals the presence of the three serpentine species lizardite chrysotile and antigorite occurring in different microstructural domains serpentine samples were investigated to obtain microstructural information preserved in the serpentine species by optical microscopy x ray powder diffraction electron microprobe spectrometry and micro raman spectroscopy the last of which is considered a reliable method for the identification of the different serpentine species two types of noble serpentine have been identified the yellow green type characterized by fine grained aggregates in marbles and the green type localized in fibrous veins in association with calcite and quartz the identification of the different serpentine types allowed us to recognize three stages of mineral crystallization characterized by i the formation of olivine bearing marbles stage 1 ii the growth of lizardite after olivine or within lizardite rich veins stage 2 and iii the replacement of lizardite by antigorite in marbles and by antigorite clinohumite in veins stage 3 these stages clarify the complex geodynamic tectonic evolution of the margna malenco system the paleozoic olivine bearing marbles margna protoliths stage 1 are subjected to extensional tectonics that brings the margna protoliths close to the malenco in a thinned extended type passive margin stage 2 finally an inversion of tectonics leads to the subduction and collision of the margna malenco system during alpine convergence stage 3 all this suggests that gem quality noble serpentine deposits may be related to different geological contexts

quantitative determination of chrysotile in massive serpentinites using dta implications for asbestos determinations there is increasing concern about the health hazard of asbestos from natural geologic deposits such as greenstones natural occurring asbestos noa therefore quantitative determination of the chrysotile asbestos content within massive serpentinites is a recurrent requirement of recent asbestos inherent law regulations due to the possible health hazard associated with the release of chrysotile fibers unfortunately the obtainment of accurate and precise quantitative figures of the actual chrysotile content is strongly complicated by typical serpentinite textures consisting of fine to ultrafine intergrowths of fibrous and non fibrous serpentine minerals often difficult to identify by conventional methods such as x ray diffraction or microanalytical approaches in this paper we propose a reliable and straightforward method for the quantitative determination of chrysotile asbestos within bulk massive serpentinites based on thermal analysis data and specifically on the distinctive thermal behavior of chrysotile lizardite and antigorite during dehydroxylation at 500 800 c deconvolution processing of dta endothermic signals in the dehydroxylation temperature range revealed good linear correlation between peak area ratios and chrysotile content for both lizardite chrysotile and antigorite chrysotile samples the dta correlation curves have been used to determine the chrysotile content in two test serpentinites revealing surprisingly high chrysotile content this novel method is of vast importance as it represents one of the most promising tools for chrysotile quantitative determinations in massive serpentinites providing unbiased and accurate responses to recent asbestos related law requirements

accumulation over the greenland ice sheet from historical and recent records water accumulation defined as precipitation minus evaporation was estimated over all of greenland as part of a program to understand changes in ice sheet mass and elevation over 360 historical and recent point accumulation estimates on the greenland ice sheet were evaluated and 276 estimates that were judged to be high quality were used to develop the accumulation map the data set includes 99 points developed as part of four investigations of the past 5 15 years these are judged to have the greatest accuracy using kriging the average accumulation over greenland is estimated to be 30 g cm 2 yr 1 for the interior part of the ice sheet above 1800 m elevation where most of the data were acquired the average accumulation is also estimated to be 30 g cm 2 yr 1 there are still many areas on the ice sheet including northwest southeast and southern greenland where accumulation is highly uncertain exceeding the mean ice sheet uncertainty at a point of 20 25 in these regions further sampling will be required to reduce uncertainty in both regional and ice sheet wide accumulation

variability in accumulation rates from gpr profiling on the west antarctic plateau isochronal layers in firn detected with ground penetrating radar gpr and dated using results from ice core analyses are used to calculate accumulation rates along a 100 km across flow profile in west antarctica accumulation rates are shown to be highly variable over short distances elevation measurements from global positioning system surveys show that accumulation rates derived from shallow horizons correlate well with surface undulations which implies that wind redistribution of snow is the leading cause of this variability temporal changes in accumulation rate over 25 185 year intervals are smoothed to along track length scales comparable to surface undulations in order to identify trends in accumulation that are likely related to changes in climate results show that accumulation rates along this profile have decreased in recent decades which is consistent with core derived time series of annual accumulation rates measured at the two ends of the radar profile these results suggest that temporal variability observed in accumulation rate records from ice cores and gpr profiles can be obscured by spatial influences although it is possible to resolve temporal signals if the effects of local topography and ice flow are quantified and removed

asbestos and other fibrous minerals contained in the serpentinites of the gimigliano mount reventino unit calabria s italy serpentinites are metamorphic rocks with good technological properties and valuable ornamental characteristics which have been exploited since ancient times actually their use is limited and monitored in several countries worldwide because they can contain fibrous asbestos minerals that may be carcinogenic furthermore certain types of fibrous minerals can be confused with asbestos and must therefore be carefully investigated we have investigated the possible presence of the asbestos and non asbestos fibrous phases contained in serpentinitic rocks in a meta ophiolitic sequence from the gimigliano mount reventino unit southern italy which had not been previously assessed the detection and quantification of asbestos and the correct distinction of the fibrous non asbestos minerals are very important not only from a scientific point of view but also from a legislative one this is especially the case for the administrative agencies that have to take decisions with regards to the implementation of public and occupational health protection measures e g in road yards and quarry excavations as a consequence of this serpentinitic rock samples have been characterized in detail through x ray powder diffraction scanning and transmission electron microscopy combined with energy dispersive spectrometry analytical electron microscopy sem eds and tem aem differential scanning calorimetry thermogravimetry and micro raman spectroscopy two kinds of asbestos and four kinds of non asbestos fibrous silicates have been detected in the examined samples in order of decreasing abundance these are polygonal serpentine chrysotile fibrous antigorite tremolite gedrite and magnesiohornblende the size morphology crystallinity and chemical composition of the fibres were also discussed in the light of the possible role these properties could play in the carcinogenic effect on human health

natural radioactivity levels k th u and rn in the cecita lake area sila massif calabria southern italy an attempt to discover correlations with soil features on a statistical base soils can exhibit a complex range of physical mineralogical and chemical features depending on many interrelated factors such as parental rock composition and mineralogy climate topography vegetation amounts and types water infiltration versus runoff soil moisture organic matter presence and types of anthropogenic contaminants and many others radioactivity as measured on these complex systems is consequently perturbed by several mixed effects in order to find out a possible potential relationship among soil properties and experimental data attributable to radioactivities of k th u and rn a detailed investigation has been performed in the cecita lake basin sila grande calabria southern italy most of the soil types outcropping in the cecita lake surroundings belong to the entisol and inceptisol orders usda united states department of agriculture 2006 keys to soil taxonomy 10th edit usda soil survey staff natural resources conservation service washington d c 333 pp representing relatively young poorly to moderately differentiated soils showing features strongly dependent on the nature of the parent rock and the climatic conditions disintegrations contributed by k th u and rn measured respectively in k ppm u and th and kbq m3 rn have been related to 13 a priori known soil unit groups with well defined general features and spatial position the data have been analysed by using graphical and numerical statistical procedures able to manage compositional data in a correct sample space the paper summarises the results of this research and highlights the conclusions drawn from these investigations particularly concerning i the modelling of the high u variability a behaviour that tends to homogenise the differences potentially attributable to soil features with the exception of situations where uranium could be enriched due to adsorption onto iron oxi hydroxides and or clay minerals or concentrated in argillic horizons due to illuviation ii the discovering of the discriminative effect of the k th ratio values particularly for soil groups where th behaviour as other tetravalent actinides is strongly affected by the presence of mineral colloids or where the presence of clays affects the trapping of k iii the clustering of the a priori known soil groups in four new sets characterised by internal similarities for rn values for which the morphology appears to be the most important discriminative effect

propagation mechanisms for the madden julian oscillation the madden julian oscillation mjo is examined using 20 years of outgoing long wave radiation and national centers for environmental prediction national center for atmospheric research re analysis data two mechanisms for the eastward propagation and regeneration of the convective anomalies are suggested the first is a local mechanism operating over the warm pool region at the phase of the mjo with a dipole structure to the convection anomalies there is enhanced tropical convection over the eastern indian ocean and reduced convection over the western pacific over the equatorial western indian ocean the equatorial rossby wave response to the west of the enhanced convection includes a region of anomalous surface divergence associated with the anomalous surface westerlies and pressure ridge this lends to suppress ascent in the boundary layer and shuts off the deep convection eventually leading to a convective anomaly of the opposite sign over the indonesian sector the equatorial kelvin wave response to the east of the enhanced convection includes a region of anomalous surface convergence into the anomalous equatorial surface easterlies and pressure trough which will tend to favour convection in this region the indonesian sector is also influenced by an equatorial rossby wave response of opposite sign to the west of die reduced convection over the western pacific which also has a region of anomalous surface convergence associated with its anomalous equatorial surface easterlies and pressure trough hence convective anomalies of either sign tend to erode themselves from the west and initiate a convective anomaly of opposite sign via their equatorial rossby wave response and expand to the east via their equatorial kelvin wave response the second mechanism is global involving an anomaly completing a circuit of the equator enhanced convection over the tropical western pacific excites a negative mean sea level pressure m s l p anomaly which radiates rapidly eastward as a dry equatorial kelvin wave at approximately 35 m s 1 over the eastern pacific it is blocked by the orographic barrier of the andes and central america for several days before propagating through the gap at panama after rapidly propagating as a dry equatorial kelvin wave over the atlantic the m s l p anomaly is delayed further by the east african highlands before it reaches the indian ocean and coincides with the development of enhanced convection at the start of the next mjo cycle

recent accumulation variability in northwest greenland from ground penetrating radar and shallow cores along the greenland inland traverse accumulation is a key parameter governing the mass balance of the greenland ice sheet several studies have documented the spatial variability of accumulation over wide spatial scales primarily using point data remote sensing or modeling direct measurements of spatially extensive detailed profiles of accumulation in greenland however are rare we used 400mhz ground penetrating radar along the 1009 km route of the greenland inland traverse from thule to summit during april and may of 2011 to image continuous internal reflecting horizons we dated these horizons using ice core chemistry at each end of the traverse using density profiles measured along the traverse we determined the depth to the horizons and the corresponding water equivalent accumulation rates the measured accumulation rates vary from 0 1mw e a in the interior to 0 7mw e a near the coast and correspond broadly with existing published model results though there are some excursions comparison of our recent accumulation rates with those collected along a similar route in the 1950s shows a 10 increase in accumulation rates over the past 52 years along most of the traverse route this implies that the increased water vapor capacity of warmer air is increasing accumulation in the interior of greenland

rapid ice discharge from southeast greenland glaciers interferometric synthetic aperture radar insar observations of southeast greenland glaciers acquired by the earth remote sensing satellites ers 1 2 in 1996 were combined with ice sounding radar data collected in the late 1990s to estimate a total discharge of 46 3 km 3 ice per year between 62 n and 66 n which is significantly lower than a mass input of 29 3 km 3 ice per year calculated from a recent compilation of snow accumulation data further north helheim glacier discharges 23 1 km 3 yr vs 30 3 km 3 yr accumulation kangerdlugssuaq glacier discharges 29 2 km 3 yr vs 23 km 3 yr and daugaard jensen glacier discharges 10 5 0 6 km 3 yr vs 10 5 1 km 3 yr the mass balance of east greenland glaciers is therefore dominated by the negative mass balance of southeast greenland glaciers 17 4 km 3 yr equivalent to a sea level rise of 0 04 0 01 mm yr warmer and drier conditions cannot explain the imbalance which we attribute to longterm changes in ice dynamics copyright 2004 by the american geophysical union

north atlantic oscillation dynamics recorded in greenland ice cores carefully selected ice core data from greenland can be used to reconstruct an annual proxy north atlantic oscillation nao index this index for the past 350 years indicates that the nao is an intermittent climate oscillation with temporally active coherent and passive incoherent phases no indication for a single persistent multiannual nao frequency is found in active phases most of the energy is located in the frequency band with periods less than about 15 years in addition variability on time scales of 80 to 90 years has been observed since the mid 19th century

enso impact on kelvin waves and associated tropical convection abstractthe impact of el nino southern oscillation enso on atmospheric kelvin waves and associated tropical convection is investigated using the ecmwf re analysis noaa outgoing longwave radiation olr and the analysis technique introduced in a previous study it is found that the phase of enso has a substantial impact on kelvin waves and associated convection over the equatorial central eastern pacific el nino la nina events enhance suppress variability of the upper tropospheric kelvin wave and the associated convection there in both extended boreal winter and summer the mechanism of the impact is through changes in the enso related thermal conditions and the ambient flow in el nino years because of sst increase in the equatorial central eastern pacific variability of eastward moving convection which is mainly associated with kelvin waves intensifies in the region in addition owing to the weakening of the equatorial eastern pacific westerly duct in the upper troposphere in el nino years

twentieth century enso characteristics in the ipcc database in this paper we assess and compare to observations the spatial characteristics of the twentieth century enso sst variability simulated by 23 models of the ipcc ar4 cmip3 database the analysis is confined to the sst anomalies along the equatorial pacific and is based on the use of a non linear neural classification algorithm the self organizing maps systematic biases include a larger than observed proportion for modelled enso maximum variability occurring in the western pacific no clear relationship is found between this bias and the characteristics of the modelled mean state bias in the equatorial pacific this bias is mainly related to a misrepresentation of both el nino and la nina termination phases for most of the models in contrast the onset phase is quite well simulated modelled el nino and la nina peak phases display an asymmetric bias whereas the main bias of the modelled el nino peak is to exhibit a maximum in the western pacific the simulated la nina bias mainly occurs in the central pacific in addition some models are able to capture the observed el nino peak characteristics while none of them realistically simulate la nina peaks it also arises that the models closest to the observations score unevenly in reproducing the different phases preventing an accurate classification of the models quality to reproduce the overall enso like variability

changes in the velocity structure of the greenland ice sheet using satellite radar interferometry observations of greenland we detected widespread glacier acceleration below 66 north between 1996 and 2000 which rapidly expanded to 70 north in 2005 accelerated ice discharge in the west and particularly in the east doubled the ice sheet mass deficit in the last decade from 90 to 220 cubic kilometers per year as more glaciers accelerate farther north the contribution of greenland to sea level rise will continue to increase

stratospheric variability of wave activity and parameters in equatorial coastal and tropical sites during the west african monsoon recent numerical studies in stratospheric dynamics and its variability as well as climate have highlighted the need of more observational analyses to improve simulation of the west african monsoon wam in this paper activity and spectral characteristics of short scale vertical waves wavelengths 4 km are analysed in equatorial coastal and tropical lower stratosphere during the wam a first detailed description of such waves over west africa is derived from high resolution vertical profiles of temperature and horizontal wind obtained during intensive observation period of the african monsoon multidisciplinary analyses amma campaign 2006 monthly variation of wave energy density is revealed to trace the progression of the inter tropical convergence zone itcz over west africa mesoscale inertia gravity waves structures with vertical and horizontal wavelengths of 1 5 2 5 and 400 1100 km respectively and intrinsic frequencies of 1 1 2 2 f or periods 2 days are observed in the tropical ls with intense activity during july and august when the wam is installed over the tropical west africa over equatorial region gravity waves with intrinsic frequencies of 1 4 4 f or periods 5 2 days vertical wavelength of 2 1 km and long horizontal wavelengths of 1300 km are intense during the wam coastal phase from july to october gravity waves with intrinsic frequencies of 1 2 3 8 f or periods 6 days vertical wavelength of 2 1 km and horizontal wavelengths of 1650 km are less intense during the wam sahelian phase of the wam march june unlike potential energy density kinetic energy density is observed to be a good proxy for the activity of short scale vertical waves during the wam because quasi inertial waves are dominant long term wave activity variation from january 2001 to december 2009 highlights strong year to year variation superimposed on convective activity and quasi biennial oscillation like variations especially above tropical stations

annual accumulation over recent centuries at four sites in central greenland 1 accurate accumulation records are fundamental to understanding mass balance of the greenland ice sheet ice cores can provide multicentury high resolution ground based point estimates of water accumulation in 2003 and 2004 four new ice cores were collected in the central western d4 and d5 and summit sandy and katie regions of greenland annual layer counting based on multiple glaciochemical parameters primarily hydrogen peroxide sea salt and dust proxies was used to date the ice cores resulting in annual dating the bottom depth ages for d4 d5 sandy and katie were estimated at 1738 1673 1844 and 1934 a d with mean annual accumulation rates of 41 4 35 2 22 4 and 22 4 cmweq yr 1 respectively these new records were in good agreement with previous accumulation maps and four previously published records from nearby multicentury ice cores spatial variability was quantified through an analysis of variance thereby allowing for more meaningful comparisons to atmospheric processes more regionally representative accumulation records were constructed for the central western and summit regions spanning recent centuries using a principle component analysis of both the new and previously reported ice core measurements these regional records exhibited 6 7 interannual variability 1 standard deviation of the mean and had lower spatial variability uncertainties than individual accumulation records correlations indicate that 20 of the variance in the central western region was explained by the north atlantic oscillation nao and suggests that an array of more northern ice cores may correlate more closely with nao

propagation of the arctic oscillation from the stratosphere to the troposphere geopotential anomalies ranging from the earth s surface to the middle stratosphere in the northern hemisphere are dominated by a mode of variability known as the arctic oscillation ao the ao is represented herein by the leading mode the first empirical orthogonal function of low frequency variability of wintertime geopotential between 1000 and 10 hpa in the middle stratosphere the signature of the ao is a nearly zonally symmetric pattern representing a strong or weak polar vortex at 1000 hpa the ao is similar to the north atlantic oscillation but with more zonal symmetry especially at high latitudes in zonal mean zonal wind the ao is seen as a north south dipole centered on 40 45 n in zonal mean temperature it is seen as a deep warm or cold polar anomaly from the upper troposphere to 10 hpa the association of the ao pattern in the troposphere with modulation of the strength of the stratospheric polar vortex provides perhaps the best measure of coupling between the stratosphere and the troposphere by examining separately time series of ao signatures at tropospheric and stratospheric levels it is shown that ao anomalies typically appear first in the stratosphere and propagate downward the midwinter correlation between the 90 day low pass filtered 10 hpa anomaly and the 1000 hpa anomaly exceeds 0 65 when the surface anomaly time series is lagged by about three weeks the tropospheric signature of the ao anomaly is characterized by substantial changes to the storm tracks and strength of the midtropospheric flow especially over the north atlantic and europe the implications of large stratospheric anomalies as precursors to changes in tropospheric weather patterns are discussed

tropical variability and stratospheric equatorial waves in the ipslcm5 model the atmospheric variability in the equatorial regions is analysed in the earth system model pre industrial simulation done at ipsl in the framework of cmip5 we find that the model has an interannual variability of about the right amplitude and temporal scale when compared to the el nino southern oscillation enso but that is too confined to the western pacific at the intra seasonal periods the model variability lacks of large scale organisation and only produces one characteristic madden julian oscillation every 10 winters typically at shorter time scales and in the troposphere the model has rossby and kelvin convectively coupled equatorial waves ccews but underestimates the kelvin ccews signal on olr in the model stratosphere a composite analysis shows that the temperature and velocities fluctuations due to the kelvin waves are quite realistic in the model nevertheless the stratospheric waves are less related to the convection than in the observations suggesting that their forcing by the midlatitudes plays a larger role still in the model the kelvin waves are not predominantly occurring during the life cycle of the tropospheric kelvin ccews a behaviour that we find to be dominant in the observations the composite analysis is also used to illustrate how the waves modify the zonal mean flow and to show that the model kelvin waves are too weak in this respect this illustrates how a model can have a reasonable kelvin waves signal on the velocities and temperature but can at the same time underestimate their amplitude to modify the mean flow we also use this very long simulation to establish that in the model the stratospheric equatorial waves are significantly affected by enso hence supporting the idea that the enso can have an influence on the quasi biennial oscillation

use of mean residence time of water flowrate and equilibrium temperature indicated by water geothermometers to rank geothermal resources application to the thermal water circuits of northern calabria abstract a new hydro geochemical survey was carried out on the thermal sites of northern calabria by use of new and historical data it was possible to improve the knowledge on the deep systems of interest first thermal waters were characterized by means of a classical approach including water classifications use of the triangular diagram of cl li b and geothermometry through suitably selected functions then the tritium based mean residence time and flowrate of the thermal waters of northern calabria were used to evaluate the volume of the geothermal reservoir and its component terms based on these results the heat stored in the geothermal reservoir was computed by means of the volume method their natural heat discharge was also calculated these parameters as well as the reservoir temperature indicated by water geothermometers were used to rank the geothermal resources of northern calabria sambiase resulted to be the thermal circuit of highest geothermal potential

asbestiform and non asbestiform morphologies in a talc and vermiculite mine from the province of cordoba argentina a case study in this work a talc and vermiculite mine from the province of cordoba argentina was investigated with special emphasis on the occurrence of asbestiform and non asbestiform phases the meta ultramafic rock was studied by a multimethodological approach complementing field studies with petrographic mineralogical compositional and morphological analyses samples were examined by stereomicroscopy polarizing light microscopy sem eds xrd dsc tga and ftir complementary compositional and textural analyses were performed with fe sem eds and epma talc rich veins with a laminar and fibrous appearance were at first recognized however the fibrous morphology observed both in the field and by microscopy is due to an apparent habit because of the sample orientation to avoid erroneous interpretations studies by secondary electron images sem are fundamental to carrying out this type of analysis tremolite was identified in different zones of the outcrop however only 40 of the crystals located in the vermiculite zone have dimensions to be considered as asbestiform fibres in the range of respirable particles in these types of complex deposits affected by superimposed metamorphic igneous and deformational events multimethodological approaches are necessary to develop models of occurrence of asbestiform morphologies that may be applicable to other with similar characteristics

the carbonate tectonic units of northern calabria italy a record of apulian palaeomargin evolution and miocene convergence continental crust subduction and exhumation of hp lt rocks in northern calabria italy the metasedimentary succession of the lungro verbicaro tectonic unit preserves mineral assemblages suggesting underthrusting to depths in excess of 40 km internal deformation of these rocks occurred continuously during the following decompression index mineral composition associated with progressively younger tectonic fabrics indicates that a substantial part of the structural evolution took place within the blueschist facies p t field despite their tectonic and metamorphic history the rocks of the lungro verbicaro unit preserve significant sedimentary and palaeontological features allowing correlations with successions included in adjacent thrust sheets and the reconstruction of the mesozoic continental margin architecture the subduction exhumation cycle recorded by the lungro verbicaro unit is entirely of miocene age this portion of the apulia continental palaeomargin was involved in convergence related deformation not earlier than the aquitanian the integration of our results with available constraints on the tectonic evolution of the apennine calabrian arc system suggests that subduction and most of the subsequent exhumation of the lungro verbicaro unit occurred up to langhian time at maximum vertical rates in excess of 15 mm a 1 the exhumation process was then completed at much slower rates 1 in late miocene time as indicated by both apatite fission track data and stratigraphic information

observed connection of the stratospheric quasi biennial oscillation with el nino southern oscillation in radiosonde data 1 using a stratospheric zonal wind data archive of radiosonde observations at equatorial stations for 1953 2008 this study investigates whether or not signals of the quasi biennial oscillation qbo vary with the el nino southern oscillation enso cycle the signals of the qbo are represented by trajectories in a phase space spanned by time series of two leading modes of wind variability two properties of the trajectories distance from the origin and time rate of change in argument which are proxies for amplitude and phase progression rate of the qbo respectively are first examined in relation to seasons and qbo phases the examination confirms known features of the qbo including the so called seasonal locking and more regular phase propagation for the westerly phase a further comparison of the properties between cold and warm enso conditions la nina and el nino respectively reveals unprecedented evidence of clear variations of the qbo with enso the qbo signals exhibit weaker amplitude and faster phase propagation for el nino conditions such variations are also supported by a composite analysis of zonal wind anomalies we also discuss a possible connection of the enso associated changes in the qbo with those in equatorial wave activity

annual accumulation for greenland updated using ice core data developed during 2000 2006 and analysis of daily coastal meteorological data an updated accumulation map for greenland is presented on the basis of 39 new ice core estimates of accumulation 256 ice sheet estimates from ice cores and snow pits used in previous maps and reanalysis of time series data from 20 coastal weather stations the period 1950 2000 is better represented by the data than are earlier periods ice sheetwide accumulation was estimated based on kriging the average accumulation 95 confidence interval or 2 times standard error over the greenland ice sheet is 30 0 2 4 g cm 2 a 1 with the average accumulation above 2000 m elevation being essentially the same 29 9 2 2 g cm 2 a 1 at higher elevations the new accumulation map maintains the main features shown in previous maps however there are five coastal areas with obvious differences southwest northwest and eastern regions where the accumulation values are 20 50 lower than previously estimated and southeast and northeast regions where the accumulation values are 20 50 higher than previously estimated these differences are almost entirely due to new coastal data the much lower accumulation in the southwest and the much higher accumulation in the southeast indicated by the current map mean that long term mass balance in both catchments is closer to steady state than previously estimated however uncertainty in these areas remains high owing to strong gradients in precipitation from the coast inland a significant and sustained precipitation measurement program will be needed to resolve this uncertainty copyright 2009 by the american geophysical union

surface melt induced acceleration of greenland ice sheet flow ice flow at a location in the equilibrium zone of the west central greenland ice sheet accelerates above the midwinter average rate during periods of summer melting the near coincidence of the ice acceleration with the duration of surface melting followed by deceleration after the melting ceases indicates that glacial sliding is enhanced by rapid migration of surface meltwater to the ice bedrock interface interannual variations in the ice acceleration are correlated with variations in the intensity of the surface melting with larger increases accompanying higher amounts of summer melting the indicated coupling between surface melting and ice sheet flow provides a mechanism for rapid large scale dynamic responses of ice sheets to climate warming

an analysis of convectively coupled kelvin waves in 20 wcrp cmip3 global coupled climate models abstract output from 20 coupled global climate models is analyzed to determine whether convectively coupled kelvin waves exist in the models and if so how their horizontal and vertical structures compare to observations model data are obtained from the world climate research program s wcrp s coupled model intercomparison project phase 3 cmip3 multimodel dataset ten of the 20 models contain spectral peaks in precipitation in the kelvin wave band and of these 10 only 5 contain wave activity distributions and three dimensional wave structures that resemble the observations thus the majority 75 of the global climate models surveyed do not accurately represent convectively coupled kelvin waves one of the primary sources of submonthly zonally propagating variability in the tropics the primary feature common to the five successful models is the convective parameterization three of the five models use the tiedtke nordeng convective scheme while the other two utilize the pan and randall scheme

structure of the monte reventino greenschist folds a contribution to untangling the tectonic transport history of calabria a key element in italian tectonics abstract calabria an anomalous pile of largely crystalline nappes resting on top of the mostly sedimentary fold thrust belts of the apennines and the sicilian maghebides has moved several hundred kilometers southeastward opening the tyrrhenian sea in its wake this study treats the monte reventino area in the northern third of crystalline calabria where pre mesozoic schist appears to rest on deep water mesozoic sedimentary rocks along a thrust surface marked by discontinuous bodies of serpentinite and banded greenschist with a complex internal structure detailed mapping led to a structural analysis of an unusual pattern of folds in the banded greenschist resulting from twisting of opposite major fold limbs in opposite directions a useful aspect of this fold distortion is that the sense of rotation of minor fold axes enables one to determine the sense of tectonic transport in this case it was generally westward for many years the structure of calabria has been thought of as a pile of nappes emplaced through entirely compressional thrusting recently some geologists have begun to reinterpret the structure as resulting from large scale low angle extensional faulting that has stretched and torn apart the nappe edifice monte reventino appears to be a key location for evaluating this possibility

changes in greenland ice sheet elevation attributed primarily to snow accumulation variability the response of grounded ice sheets to a changing climate critically influences possible future changes in sea level recent satellite surveys over southern greenland show little overall elevation change at higher elevations but large spatial variability using satellite studies alone it is not possible to determine the geophysical processes responsible for the observed elevation changes and to decide if recent rates of change exceed the natural variability here we derive changes in ice sheet elevation in southern greenland for the years 1978 88 using a physically based model of firn densification and records of annual snow accumulation reconstructed from 12 ice cores at high elevation our patterns of accumulation driven elevation change agree closely with contemporaneous satellite measurements of ice sheet elevation change and we therefore attribute the changes observed in 1978 88 to variability in snow accumulation similar analyses of longer ice core records show that in this decade the greenland ice sheet exhibited typical variability at high elevations well within the long term natural variability our results indicate that a better understanding of ice sheet mass changes will require long term measurements of both surface elevation and snow accumulation

mountain torques and northern hemisphere low frequency variability part i hemispheric aspects the ncep ncar reanalysis dataset for 1958 97 is used to analyze intraseasonal variations in mountain torques and the large scale atmospheric circulation patterns associated with them spectral analysis of the atmospheric angular momentum aam budget shows that the dominant variations of mountain torque have periodicities near 30 days and shorter while the dominant aam variations occur in the 40 60 day band this difference is due to the 40 60 day aam variations being primarily related to equatorial processes while mountain torque variations are associated mostly with extratropical processes the northern hemisphere nh mountain torque has enhanced power and significant spectral peaks in the 20 30 day band the signal in this band accounts for 33 of the nh mountain torque variance once the seasonal cycle has been removed lag composites of the nh 700 hpa geopotential heights based on the 20 30 day mountain torque signal show the latter to be associated with coherent large scale patterns that resemble lowfrequency oscillations identified in this band by previous authors the composite patterns that are in phase quadrature with the 20 30 day nh mountain torque have a pronounced zonally symmetric component these patterns are associated with substantial aam variations arguably driven by the nh mountain torque in this band principal component pc analysis of the nh 700 hpa heights shows that in the 20 30 day band the mountain torque is also in phase quadrature with the two leading pcs the first corresponds to changes in the midlatitude jet intensity near the subtropics while the second corresponds to the arctic oscillation the relationships with aam of the latter essentially occurs through the mass term mountain torques are furthermore nearly in phase with dominant patterns of low frequency variability that exhibit substantial pressure gradients across the rockies and the tibetan plateau

hydrologic response of the greenland ice sheet the role of oceanographic warming the response of the greenland ice sheet to ongoing climate change remains an area of great uncertainty with most previous studies having concentrated on the contribution of the atmosphere to the ice mass balance signature here we systematically assess for the first time the influence of oceanographic changes on the ice sheet the first part of this assessment involves a statistical analysis and interpretation of the relative changes and variations in sea surface temperatures ssts and air temperatures around greenland for the period 1870 2007 this analysis is based on hadisst1 and reynolds oi v2 sst analyses in situ sst and deeper ocean temperature series surface air temperature records for key points located around the greenland coast and examination of atmospheric pressure and geopotential height from ncep ncar reanalysis second we carried out a novel sensitivity experiment in which ssts were perturbed as input to a regional climate model and document the resulting effects on simulated greenland climate and surface mass balance we conclude that sea surface ocean temperature forcing is not sufficient to strongly influence precipitation snow accumulation and melt runoff of the ice sheet additional evidence from meteorological reanalysis suggests that high greenland melt anomalies of summer 2007 are likely to have been primarily forced by anomalous advection of warm air masses over the ice sheet and to have therefore had a more remote atmospheric origin however there is a striking correspondence between ocean warming and dramatic accelerations and retreats of key greenland outlet glaciers in both southeast and southwest greenland during the late 1990s and early 2000s copyright 2008 john wiley sons ltd

annual accumulation at two sites in northwest greenland during recent centuries during summer 1995 150 m firn and ice cores were drilled to determine annual accumulation rates at two greenland sites 73 84 n 49 49 w nasa u site and 78 53 n 56 83 w humboldt glacier site annual layers were identified in the cores using multiple parameters 18 o and concentrations of dust h 2 o 2 nh 4 ca 2 and no 3 using all parameters together to define annual layers resulted in a 350 year record for the nasa u core with no dating uncertainty for the lower accumulation humboldt core the dating uncertainty is about 5 years over the 852 year period of record with no uncertainty over the past 200 years annual accumulation over the periods of record at the two sites averaged about 0 34 and 0 14 m water equivalent respectively a set of 20 m firn cores drilled near the main 150 m cores showed that interannual variability of accumulation exceeded spatial variability at nasa u the humboldt cores showed equal spatial and interannual variability the accumulation rates at both sites showed a low frequency variation of about 100 years and both sites showed 200 year cumulative fluctuations of about 2 m from mean accumulation rates compared to central greenland and to nasa u the humboldt core showed higher annual accumulation rates around 1760 1810 possibly indicating a changed circulation pattern for the more northern part of greenland in that period

mass balance of higher elevation parts of the greenland ice sheet satellite radar and aircraft laser altimeter data and a volume budget comparison of total snow accumulation with total ice discharge give three independent estimates of the recent mass balance of parts of the greenland ice sheet above 2000 m elevation results show the entire region on average to be in balance to within 10 mm yr 1 with very low rates of regional thickness change dh dt in the northeast but high rates with large spatial variability in the south only the volume budget estimates show significant thinning in the northwest but thinning in this area is also inferred from local measurements of ice vertical velocities down boreholes south of latitude 68 n there has been rapid thickening west of the ice divide with equally rapid thinning in the southeast but with large differences between the three estimates of dh dt throughout this region the radar data apply to the period 1978 1988 the laser data are for 1993 1994 1998 1999 and the volume budget calculations represent conditions over at least the last few decades consequently many of the differences between results could be caused by temporal changes particularly in snow accumulation rates that occurred since the 1970s however taken with other information our results suggest long term thickening in the southwest and possibly quite recent onset of rapid thinning in the southeast

predictive assessment of the asbestos content in the western italian alps an essential tool for an effective approach to risk analysis and management in tunneling operations and muck reuse the modern approach to the design and management of tunnel excavation and muck reuse can be influenced to a great extent by the possible presence of rock formations containing asbestos minerals this situation creates problems concerning the protection of the workers health and the expectable environmental criticalities while a drastic re consideration of the muck destination is necessary since in the case of carcinogens corrective action following exposure or dispersion is not acceptable detailed knowledge of the characteristics of the material to be excavated is all the more essential only on this basis it is possible to design the tunneling operations in a prevention through design approach so that the tunnel driving techniques fittings and technologies and special equipment and modus operandi can grant where necessary minimized risk conditions and make a correct decision on whether how and when these measures must be fully activated since such an approach involves a remarkable impact on costs and work organization in the western alps a detailed identification and quantification of the asbestos content in rocks is a difficult task due to the fact that the asbestos in the host rocks mainly serpentinite shows a highly variable distribution typical of ophiolitic belts throughout the world as it is mostly associated with joints and shear zones the possibilities of a predictive assessment of the asbestos content in the formations to be excavated are here discussed with special reference to the reliability of the achievable results

interannual variations of snow accumulation on the greenland ice sheet 1985 1996 new observations versus model predictions newly measured time series of net water equivalent accumulation from ice cores are reported for 11 sites located near the 2000 m contour of the greenland ice sheet many of these sites are located in regions where accumulation has not been previously measured we compared these new time series of annual accumulation with previously reported modeled precipitation covering the same time range because ice core accumulation records include both regional and local accumulation components we used adjacent ice core records at six multiple core sites to estimate the local component and extrapolated these results to the five single core sites we investigated the impact of this short scale spatial variability in accumulation on statistical comparisons between the observed accumulation and model precipitation although sealers were required to match the 12 year mean modeled precipitation to the mean observed accumulation a high degree of correspondence between observed interannual accumulation and scaled modeled precipitation was found at 7 of 11 locations the need for scaling and the low correspondence between model simulations and observations at some sites clearly indicate that model improvements are needed although very encouraging a more spatially distributed array of ice core accumulation measurements spanning the same time period as the precipitation modeling is necessary for continued model improvement and validation in agreement with earlier studies the large temporal variability in snow accumulation predicted by modeling and confirmed by ice cores indicates that the ice sheet elevation varies by tens of centimeters from year to year simply because of changing accumulation

serpentine minerals discrimination by thermal analysis this paper reports a complete set of tg dtg and dta data coupled with emitted gas analysis for well constrained almost pure serpentine samples serpentine dehydroxylation takes place between 550 and 800 c with dtg and dta peak temperatures progressively decreasing from antigorite 720 and 715 c respectively to lizardite 708 and 714 c polygonal serpentine 685 and 691 c and chrysotile 650 and 654 c antigorite has an additional diagnostic signal at 740 760 c always absent in the other serpentines and dependent on antigorite superperiodicity t shift of 20 c from 36 to 49 a modulation wavelength a sharp exothermic peak occurs at extremely constant temperatures 820 c independently from the starting serpentine structure the high t mineral assemblage is always represented by forsterite and enstatite based on the observed relationships between serpentine structures and dtg dta dehydroxylation temperatures thermal analysis may represent a useful tool for serpentine identification particularly in the case of natural massive samples where different varieties are mutually intermixed the accurate definition of serpentine mineralogy would have obvious implications in both geological petrological and health related issues

effect of el nino southern oscillation on the dynamical thermal and chemical structure of the middle atmosphere 1 a simulation of the middle atmosphere is presented using a general circulation model gcm forced with observed sea surface temperature for the period 1950 2000 the gcm extends to the lower thermosphere and reproduces realistic dynamical and temperature distributions the period contains several el nino and la nina events which are identified using the nino3 index composite anomalies of relevant meteorological fields are obtained by stratifying the northern winter season according to the nino3 index these anomalies have the structure of vertically propagating planetary waves extending from the troposphere to the mesosphere circulation anomalies in the middle atmosphere are accompanied by large temperature anomalies that are of opposite sign in the stratosphere and mesosphere the former being warmer and the latter colder during el nino events near the summer mesopause changes in momentum deposition by parameterized gravity waves results in warming during el nino detailed statistical analysis is used to determine the significance of these anomalies a chemical transport simulation is carried out using output from the gcm it shows that when the lower stratosphere is colder as during la nina events some ozone depletion takes place conversely when the lower stratosphere is warmer and more disturbed as is the case during el nino events heterogeneous chemical processes are inhibited

observed and modeled greenland ice sheet snow accumulation 1958 2003 and links with regional climate forcing abstract annual and monthly snow accumulation for the greenland ice sheet was derived from ecmwf forecasts mainly 40 yr ecmwr re analysis era 40 and further meteorological modeling modeled accumulation was validated using 58 ice core accumulation datasets across the ice sheet and was found to be 95 of the observed accumulation on average with a mean correlation of 0 53 between modeled and observed many of the ice core datasets are new and are presented here for the first time central and northern interior parts of the ice sheet were found to be 10 30 too dry in era 40 in line with earlier ecmwf analysis although too much 50 locally snow accumulation was modeled for interior southern parts of greenland nevertheless 47 of 58 sites show significant correlation in temporal variability of modeled with observed accumulation the model also captures the absolute amount of snow accumulation at several sites most notably das1 and das2 in southeast greenland mean modeled accumulation over the

atmospheric response to the north atlantic ocean variability on seasonal to decadal time scales the ncep twentieth century reanalyis and a 500 year control simulation with the ipsl cm5 climate model are used to assess the influence of ocean atmosphere coupling in the north atlantic region at seasonal to decadal time scales at the seasonal scale the air sea interaction patterns are similar in the model and observations in both a statistically significant summer sea surface temperature sst anomaly with a horseshoe shape leads an atmospheric signal that resembles the north atlantic oscillation nao during the winter the air sea interactions in the model thus seem realistic although the amplitude of the atmospheric signal is half that observed and it is detected throughout the cold season while it is significant only in late fall and early winter in the observations in both model and observations the north atlantic horseshoe sst anomaly pattern is in part generated by the spring and summer internal atmospheric variability in the model the influence of the ocean dynamics can be assessed and is found to contribute to the sst anomaly in particular at the decadal scale indeed the north atlantic sst anomalies that follow an intensification of the atlantic meridional overturning circulation amoc by about 9 years or an intensification of a clockwise intergyre gyre in the atlantic ocean by 6 years resemble the horseshoe pattern and are also similar to the model atlantic multidecadal oscillation amo as the amoc is shown to have a significant impact on the winter nao most strongly when it leads by 9 years the decadal interactions in the model are consistent with the seasonal analysis in the observations there is also a strong correlation between the amo and the sst horseshoe pattern that influences the nao the analogy with the coupled model suggests that the natural variability of the amoc and the gyre circulation might influence the climate of the north atlantic region at the decadal scale

accumulation map for the greenland ice sheet 1971 1990 an updated accumulation map for the greenland ice sheet for the period 1971 1990 based on kriging of accurate point estimates developed during the past decade at over 40 points plus over 200 historical points shows an average water accumulation of 30 g cm 2yr 1 average uncertainty standard deviation in estimates of point accumulation for the interior part of the ice sheet where the kriging drift surface is well constrained is approximately 7 g cm 2yr 1 or 24 of mean accumulation because there are multiple cores in most regions the regional uncertainty in accumulation should be considerably lower than the 7 g cm 2yr 1 average uncertainty at a point there are still many areas on the ice sheet including northwest and southern greenland where annual accumulation remains poorly constrained

dissolution rate of antigorite from a whole rock experimental study of serpentinite dissolution from 2 ph 9 at 25 c implications for carbon mitigation via enhanced serpentinite weathering serpentinite rock dissolution experiments at 25 c and 2 ph 9 were used to retrieve antigorite dissolution rates as its high abundance and comparatively fast dissolution dominate element release from the rock retrieved antigorite dissolution rates at ph 2 02 and 3 06 are similar to previous literature data for serpentine minerals at corresponding ph in contrast retrieved rates at higher ph are considerably lower than corresponding literature data nonetheless the retrieved rates at ph 5 76 and 7 28 are consistent with the linear log rate ph relationship of orlando et al 2011 suggesting that rates follow a single acidic mechanism to a ph of at least 7 3 the relatively low dissolution rates of serpentine minerals found in this study suggests that significantly more time is required for serpentine weathering than that estimated using the dissolution rates of these solids reported by marini 2006 based on a review of literature data as such using enhanced serpentine weathering as a carbon capture storage strategy may be less efficient than previously assumed

hydrogeochemical study of an ophiolitic aquifer a case study of lago southern italy calabria a hydrogeochemical survey was carried out in the area of lago calabria region southern italy and outcropping geological units were classified from the hydrogeological point of view to explain the evolution of local groundwaters in addition reaction path modeling was performed to simulate the evolution of groundwaters upon interaction with local metabasalts phyllites and serpentinites by means of the eq3 6 software package version 8 0 simulations were carried at constant temperature of 14 1 c which reproduces the average temperature of local groundwaters three different simulations have been performed for the average metabasalt fixing the fugacity of co2 at either 10 2 4 bar mean value 10 2 0 bar mean value 1 or 10 2 9 bar mean value 1 the simulation for the average serpentinite and phyllite was carried out at the mean value of the fugacity of co2 10 2 4 bar all evidences acquired in this study namely the hydrogeological framework the chemical analysis of local groundwaters and the results of reaction path modeling consistently point out that groundwater circulation under ordinary hydraulic gradient primarily occurs in the ophiolitic sub complex and that dissolution of metabasalts and serpentinites controls the chemical characteristics of the groundwaters from the study area

enso related variation of equatorial mrg and rossby waves and forcing from higher latitudes the contrasting behaviour of westward moving mixed rossby gravity wmrg and the first rossby r1 waves in el nino en and la nina ln seasons is documented with a focus on the northern hemisphere winter the eastward moving variance in the upper troposphere is dominated by wmrg and r1 structures that appear to be doppler shifted by the flow and are referred to as wmrg e and r1 e in the east pacific and atlantic the years with stronger equatorial westerly winds have the stronger wmrg and wmrg e in the east pacific r1 is also a maximum in ln however r1 e exhibits an eastward shift between ln and en the changes with enso phase provide a test bed for the understanding of these waves in the east pacific and atlantic the stronger wmrg e and wmrg with stronger westerlies are in accord with the dispersion relation with simple doppler shifting by the zonal flow the possible existence of free waves can also explain stronger r1 in en in the eastern hemisphere 1 d free wave propagation theory based on wave activity conservation is also important for r1 however this theory is unable to explain the amplitude maxima for other waves observed in the strong equatorial westerly regions in the western hemisphere and certainly not their enso related variation the forcing of equatorial waves by higher latitude wave activity and its variation with enso phase is therefore examined propagation of extratropical eastward moving rossby wave activity through the westerly ducts into the equatorial region where it triggers wmrg e is favoured in the stronger westerlies in ln in the east pacific and en in the atlantic it is also found that wmrg is forced by southern hemisphere westward moving wavetrains arching into the equatorial region where they are reflected the most significant mechanism for both r1 and r1 e appear to be lateral forcing by subtropical wavetrains

new precipitation and accumulation maps for greenland annual total precipitation and the annual accumulation on the greenland ice sheet are evaluated and presented in two maps the maps are based on accumulation measurements of 25 1 pits and cores obtained from the upper accumulation zone and precipitation measurements made at 35 meteorological stations in the coastal region to construct the accumulation map the annual precipitation was split into solid and liquid precipitation components annual total precipitation exceeding 2500 mm w e occurs on the southeastern tip of greenland while the minimum precipitation is estimated to occur on the northeastern slope of the ice sheet the mean annual precipitation for all of greenland is 340 mm w e the largest annual accumulation of about 1500 mm w e is found on the glaciers in the southeastern corner of greenland while the smallest accumulation is found on the northeastern slope of the ice sheet west of danmarkshavn the mean accumulation on the greenland ice sheet is estimated at 310 mm w e the regional difference in accumulation is examined with respect to the 850 hpa m bar level circulation the present surface topography is found to play an important role in determining regional accumulation on the ice sheet

a climatology of the gravest waves in the equatorial lower and middle stratosphere method and results for the era 40 re analysis and the lmdz gcm abstract a climatology of the three dimensional life cycle of the gravest waves in the tropical lower and middle stratosphere is presented it shows that at periods around 10 days the gravest waves correspond to kelvin and rossby gravity wave packets that substantially affect specific regions in the lower stratosphere it also shows that the planetary scale kelvin waves with zonal wavenumber s 1 and periods between 10 and 20 days produce a substantial signal still at the planetary scales the climatology also shows that the global planetary rossby waves with s 1 and periods around 5 and 16 days have a substantial equatorial signature this climatology is for all the dynamical fields horizontal wind temperature and geopotential height and relates the equatorial waves to the equatorial zonal mean flow evolution associated with the quasi biennial oscillation the method used to extract the climatology is a composite analysis of the dynamical fields keyed on simple indexes measuring when the waves en

the excitation of equatorial waves by deep convection in the ncar community climate model ccm3 the forcing of equatorial waves by convective heating in the national center for atmospheric research community climate model ccm3 is investigated and compared with the forcing deduced from observations of convective clouds the analysis is performed on two different simulations wherein convection is represented by the zhang mcfarlane and the hack parameterization schemes respectively spectra of equatorial waves excited by convective heating rossby kelvin and gravity waves are obtained by projecting the heating field onto hough modes the dynamical response to the heating is then calculated in terms of the vertical component of the eliassen palm flux fz focusing on waves that are able to propagate into the middle atmosphere the same analysis is repeated using observations of outgoing longwave radiation as a proxy for tropical convection comparison of ccm3 results with those derived from observations indicates that high frequency heating variability is underestimated in both ccm3 simulations despite the fact that time mean values of convective heating are well represented moreover the two convective parameterization schemes differ substantially from each other compared to observations fz is severely underestimated at most frequencies when ccm3 is run with the zhang mcfarlane scheme when the hack scheme is used fz at frequencies v 0 5 cycles per day is comparable to the observations but it is underestimated at higher frequencies misrepresentation of the variability of convective heating is likely to have important consequences for the dynamical simulation of the middle atmosphere and even the troposphere