three eurasian teleconnection patterns spatial structures temporal variability and associated winter climate anomalies the eurasian eu pattern is a distinct teleconnection pattern observed in boreal winter since the eu pattern was first identified three types have been reported in the literature the conventional eu pattern the type 1 eu pattern or scandinavian scand pattern and the type 2 eu pattern or east atlantic west russia eatl wrus pattern based on several reanalysis and observational datasets the three eu patterns are extracted using the rotated empirical orthogonal function method in order to provide a further distinction and understanding of the three eu patterns a comprehensive side by side comparison is performed among them including their temporal variability horizontal and vertical structure related stationary rossby wave activity impact on climate and possible driving factors associated with external forcing the results reveal that all three eu patterns are characterised by a clear quasi barotropic wave train structure but each has a distinct source and centre of action accordingly their impacts on the precipitation and surface air temperature also differ from one other further evidence suggests that the conventional eu pattern is likely driven by anomalous sea surface temperatures sst over the north atlantic in which process the transient eddies are actively involved the scand pattern is partly maintained by the vorticity source over western europe which arises from the anomalous convergence divergence over the mediterranean and is efficiently driven by the tropical and southern indian ocean sst via divergent circulation the eatl wrus pattern shows some linkage to the north american snow cover and the involved process remains unclear and needs further investigation

u pb zircon and monazite dating of a mafic ultramafic complex and its country rocks u pb data on zircons from the largest mafic ultramafic body 6 2 km of the french central massif sauviat sur vige yield the following age results primary magmatic crystallization of the gabbroic and peridotitic protoliths took place in the cambro ordovician 496 25 17 m y variable transformation under eclogite facies conditions was hercynian 320 29 36 m y the same age pattern derived by u pb monazite analyses was found also for the immediate country rocks i e kyanite bearing coarse grained metagranites occurring to the w and n of the sauviat massif due to the fact that there is no regional hercynian high grade metamorphism in this part of the french central massif e g duthou 1977 bernard griffiths 1975 both mafic ultramafic complex as well as immediate felsic country rocks must have been emplaced tectonically into pre hercynian acadian caledonian crustal rocks the cause for such a hercynian tectonism is thought to be due to continent continent collision of the spanish with the armorican plate

metamorphosed and dismembered ophiolite suites in the basement units of the eastern alps abstract the pre alpine basement of the eastern alps contains several ultramafic mafic rock complexes four of which have been investigated although polyphase deformation and metamorphism obscures much of the primary features field petrographical and geochemical evidence favours ophiolitic origins in mid ocean ridge and back arc tectonic settings the stubach complex belongs to the penninic basement of the tauern window and is interpreted as an obducted back arc ophiolite with ultramafic cumulates gabbro and minor amounts of basalt which shows the geochemistry of subduction related magma generation the rating complex belongs to a group of strongly dismembered basement slices carrying the palaeozoic austroalpine sequence of the northern greywacke zone basaltic rocks are accompanied by former metamorphic peridotite containing chromite concentrations nearly all members of an ophiolite suite are present in the speik complex in the austro alpine crystalline basement the source rocks are metamorphic peridotite harzburgite with chromite occurrences cumulate ultramafic and mafic rocks isotropic gabbro basalt and or dolerite and oceanic sediments the plankogel complex also part of the austro alpine crystalline basement represents a tectonic melange blocks of serpentinite and amphibolite derived from metamorphic peridotites and mid ocean ridge basalts together with marble and quartzite are contained in a micaschist matrix admixed is a rock assemblage with alkali basaltic amphibolites interpreted as a seamount environment the ritting plankogel and possibly parts of the speik complexes contain relict high pressure minerals and therefore went through a stage of subduction the inferred ages of all complexes is late precambrian to early palaeozoic the ophiolite suites have their distinct characteristics and contrasting tectonic settings and are therefore considered to be genetically unrelated to each other

impact of ural blocking on winter warm arctic cold eurasian anomalies part i blocking induced amplification abstractin part i of this study the impact of ural blocking ub on the warm arctic cold eurasian wace pattern associated with the winter djf arctic sea ice loss during 1979 2013 is examined by dividing the arctic sea ice reduction region into two dominant subregions the barents and kara seas bks and the north american high latitude nah region baffin and hudson bay davis strait and labrador sea it is found that atmospheric response to arctic sea ice loss resembles a negative arctic response oscillation with a dominant positive height anomaly over the eurasian subarctic region regression analyses of the two subregions further show that the sea ice loss over the bks corresponds to the ub pattern together with a positive north atlantic oscillation nao and is followed by a wace anomaly while the sea ice reduction in the nah region corresponds to a negative nao nao pattern with a cold anomaly over northern eurasia further analyses reveal that the ub pattern is more persistent during the

tectonics and plate tectonics model for the variscan belt of europe abstract a plate tectonics model is presented to explain the tectonometamorphic characteristics of the european variscides after the closing of two oceanic domains by two sided subduction 500 420 ma and obduction 420 380 ma collision of the european and african continental plates occurred we propose that the subsequent complex intracontinental deformation 380 290 ma is the result of a double subduction of the continental lithosphere accompanied by crust mantle decollement this mechanism explains the progressive crustal thickening and migration of the deformation through time from the sutures toward the external parts of the variscan belt accounting for this model and for the relationships between the european variscides and the other paleozoic peri atlantic belts caledonides appalachian mauritanides and morocco we infer the relative positions of africa america and europe between the silurian and the permian

concepts of the evolution of the austroalpine basement complex eastern alps during the caledonian variscan cycle the austroalpine basement complex has a complicated pre alpidic history which begins with the caledonian era in the late precambrian and early paleozoic a magmatic sedimentary rock sequence is formed presumably in an island arc or active continental margin environment subduction with eclogite formation is followed by collision high grade metamorphism and anatexis in the ordovician this caledonian basement is preserved in parts of the austroalpine crystalline mass the post caledonian deposits are mainly shelf type sediments with intercalated volcanics although there is evidence for an oceanic basin to the south the variscan facies zones are arranged in sw ne direction oblique to the alpidic trend in a first stage of variscan orogeny in the carboniferous south east vergent decollement nappes syntectonic flysch deposits and granitoids are formed along with regional metamorphism this is followed by a second stage in the permian with north west vergent thrusting renewed granite formation and metamorphism the variscan nappe pile is today exposed in a deeper level in the west or northwest than in the east or southeast

classification seasonality and persistence of low frequency atmospheric circulation patterns abstract orthogonally rotated principle component analysis rpca of northern hemisphere 1 month mean 700 mb heights is used to identify and describe the seasonality and persistence of the major modes of interannual variability the analysis is detailed and comprehensive in that 1 a high resolution approximately equal area 358 point grid is used for the virtually maximum possible 35 year period of record 2 a positive bias in the nmc data base in the early 1950s in the subtropics is largely eliminated for the first time and 3 homogeneous separate analyses of each month of the year are carried out detailing the mouth to month changes in the dominant circulation patterns winter results are similar to those of other recent rpca and teleconnection studies except that some less obvious patterns are identified and further detail of the better known patterns is provided two north south dipole patterns are found over the pacific ocean west pacific oscillation and east pacific pattern and over the atla

paleozoic tectonostratigraphic units of the northwest and central dinarides and the adjoining south tisia in the central dinarides and south tisia different paleozoic complexes occur in four geotectonic zones 1 comparatively autochthonous units located in the cores of disrupted anticlines of the external dinarides 2 allochthonous disrupted units accompanied by more predominant triassic formations in the sava nappe which is thrust onto the northeastern margin of the external dinarides 3 allochthonous disrupted units also together with triassic formations in the pannonian and durmitor nappes of the internal dinarides and 4 polymetamorphic sequences in basement of the pannonian basin and south tisia respectively this paper presents basic geological features for the main paleozoic areas included in these four zones the tectonostratigraphic units of the first two zones were related to the gondwana passive continental margin those of the third zone to the paleotethyan oceanic realm and those of tisia to the active laurussia margin geodynamic evolution of all these paleozoic complexes was related to opening and closure of the rheic and paleotethys oceans rifting processes along north gondwana started in the silurian locally in the cambrian ordovician and were followed by the late silurian devonian opening of the paleotethys subduction processes were active by the end of the devonian and at the beginning of the carboniferous along the laurussia margin they were followed during the westphalian by main variscan deformation during collision of gondwana and laurussia associated metamorphism was very low grade in the paleozoic units of the sava nappe low grade to epidote amphibolite grade within the paleozoic complexes of the pannonian and durmitor nappes in the internal dinarides and poly metamorphic with migmatites and granitoids in south tisia these processes gave rise to a pangea stage with the variscan basement disconformably overlain by late carboniferous and permian sediments

tropospheric precursors of anomalous northern hemisphere stratospheric polar vortices regional extratropical tropospheric variability in the north pacific and eastern europe is well correlated with variability in the northern hemisphere wintertime stratospheric polar vortex in both the ecmwf reanalysis record and in the whole atmosphere community climate model to explain this correlation the link between stratospheric vertical eliassen palm flux variability and tropospheric variability is analyzed simple reasoning shows that variability in the north pacific and eastern europe can deepen or flatten the wintertime tropospheric stationary waves and in particular its wavenumber 1 and 2 components thus providing a physical explanation for the correlation between these regions and vortex weakening these two pathways begin to weaken the upper stratospheric vortex nearly immediately with a peak influence apparent after a lag of some 20 days the influence then appears to propagate downward in time as expected from wave mean flow interaction theory these patterns are influenced by enso and october eurasian snow cover perturbations in the vortex induced by the two regions add linearly these two patterns and the quasi biennial oscillation qbo are linearly related to 40 of polar vortex variability during winter in the reanalysis record

accretionary history and crustal evolution of the variscan belt in western europe abstract the variscan belt of western europe is part of a large intra paleozoic belt extending on both sides of the atlantic from the ouachitas in the us and the mauritanides in west africa to the bohemian massif in czechoslovakia and poland the belt was constructed between 500 and 250 ma as a result of convergence and collision between two main continents laurentia baltica and africa after the closure of various oceanic basins iapetus rheic and galicia massif central now recorded as discrete in part cryptic sutures which form the roots of large crystalline nappes in which are found dismembered remnants of oceanic crust and mantle the accretionary history of the variscan belt in western europe is related to the progressive closure of probably two oceanic basins the rheic in the north and another the galicia massif central in the south by respectively southward and northward intraoceanic subduction followed by obduction and intracontinental lithospheric subduction the result is a broad 700 800 km fan like divergent belt which must be considered as a classical obduction collision orogen with a long intracontinental history of about 100 150 ma its arcuate shape is probably due to the northwestward impingement of a promontory of the african continent into laurentia baltica

scandinavian pattern and its climatic impact a lasg institute of atmospheric physics chinese academy of sciences beijing china b department of earth and planetary science university of tokyo tokyo japan maintenance mechanisms of the scandinavian teleconnection pattern and its possible impact on the eurasian climate are investigated on the basis of long term monthly data its upstream portion over the north atlantic is forced and maintained by feedback forcing from transient eddies migrating along the nearby storm track with an additional contribution from incoming rossby wave activity from further upstream the primary anomaly centre over the scandinavian peninsula and the downstream portion of the pattern manifest themselves basically as rossby waves propagating towards central siberia and east asia under the modest feedback forcing from transient eddies the pattern shows apparent seasonality in its dynamical properties including the wave train orientation and wavelength under the seasonally varying transient eddy feedback forcing and waveguide structure for rossby waves in cold seasons the positive phase of the pattern causes cold air accumulation over a vast area extending from western siberia to the regions around lake baikal and lake balkhash while giving rise to decreased precipitation over northeastern europe western siberia and some of the arctic coastal regions the pattern also changes the north atlantic sea surface temperature differently between autumn and winter

metallogenesis of the french part of the variscan orogen part ii time space relationships between u au and snw ore deposition and geodynamic events mineralogical and upb data abstract mineralogical geochemical structural and isotopic u pb studies were carried out on representative uranium and gold deposits from the french part of the variscan orogen results are compared with complementary data from the literature in order to propose a reconstruction of the metallogenesis in the variscan terranes with a particular emphasis on u deposits the data show that the early metal concentrations or pre enrichments in the terranes are affected by successive metallogenic stages which caused significant metal transport and deposition thus the significant geodynamic events which affected the variscan terranes were responsible for multistage metal deposition or alteration of the early concentrations and for the superimposed features of the metal deposits u pb geochronological results complemented by a compilation of geochronological data on u and pb zn ba f deposits show that three major stages of u deposition took place in western europe in the periods 325 300 ma 290 260 ma and 190 170 ma in addition small uranium mineralization events have been dated at 425 ma 90 110 ma and as tertiary about 40 ma the permo stephanian stage is associated with late brittle deformation associated with major shear zone movements and constitutes the major stage of u concentration the jurassic phase has a prominent part in the hydrothermal remobilization of uranium and in f ba pb zn deposition throughout western europe especially in the eastern part of the massif central other stages correspond to subordinate uranium migration within variscan terranes during earlier or later geodynamic phases the silurian metamorphism in vendee and the mesozoic to tertiary tectonic movements related to the pyrenean or alpine orogenies in the south eastern part of the massif central and in the alps data available on au and sn w as sb deposits have been considered for comparison with the u metallogenesis stages related to the deposition of such metals display significant similarities with those related to uranium deposition they occurred mostly during visean to permian events related to the intrusion of the late visean sn w and late carboniferous sn w li f granitoids and to the late brittle deformation stages which affected the hercynian basement in the vicinity of major shear zones au as sb however the significant discrepancies between the physical chemical conditions of solubilization transport and deposition of the metal led to distinct deposit location independently of the metal source location within the terranes

revealing exhumation of the central alps during the early oligocene by detrital zircon u pb age and fission track double dating in the taveyannaz formation

kinematics of cretaceous nappe tectonics in the austroalpine basement of the koralpe region eastern austria krohe a 1987 kinematics of cretaceous nappe tectonics in the austroalpine basement of the koralpe region eastern austria tectonophysicz 136 171 196 the austroalpine basement of the koralpe area austria was affected by penetrative ductile deformation in the cretaceous three metamorphic events have been established ht lp metamorphism of unknown age a hercynian mt mp metamorphism and a cretaceous eo alpine mt mp metamorphism in the koralpe area cretaceous rb sr cooling ages of muscovite indicate temperatures of at least 500 o c during the eo alpine event the most intense deformation occurred along intracrustal shear zones plattengneis north to northeast directed thrusting is indicated by an inverted metamorphic gradient regional transposition of an older foliation s c fabrics and oblique quartz fabrics after development of high temperature mylonites low angle normal shear zones low temperature mylonites cut the uppermost parts of the austroalpine basement and indicate an extensional tectonic setting at about 85 to 90 ma s c and quartz fabrics indicate downdip movements of the hanging wall towards the northeast intracrystalline a slip in quartz caused strong preferred lattice orientation in high and low temperature mylonites during the e alpine deformation the basal a slip system is more pronounced at lower temperatures whereas a prism a system predominates at higher temperatures the overall kinematic history of the austroalpine nappe complex in the study area suggests a model in which an intracrustal south over north imbrication took place in an early stage of eo alpine collision these movements were outlasted by sinistral strike slip movement possibly due to oblique collision along irregular margins of the austroalpine and brianpnnais complexes the collision imbrication process resulted in crustal thickening isostatic uplift and thus extension of the higher parts of the crust low angle normal faulting initiated sedimentation in the intramontane c tic gosau basins of late cretaceous age

geographical dependence of upper level blocking formation associated with intraseasonal amplification of the siberian high abstract intraseasonal amplification events of the surface siberian high in winter are generally associated with blocking ridge formation in the upper troposphere composite analysis applied to the 20 strongest intraseasonal events of upper level anticyclonic anomalies at every grid point over siberia reveals that the blocking formation differs fundamentally between the east and west of the climatological upper level trough over the far east to the west what can be called wave train atlantic origin type is common where a blocking ridge develops from anomalies as a component of a quasi stationary rossby wave train propagating across the eurasian continent under modest feedback forcing from transient eddies to the east of the trough what can be called pacific origin type dominates where a blocking ridge forms in association with westward development of anticyclonic anomalies from the north pacific under stronger feedback forcing from the pacific storm track regardless of a particular type of bl

examples of the horizontal propagation of quasi stationary waves abstract examples of the diagnostic of the horizontal propagation of stationary wave activity proposed by plumb are presented for a simple model of the atmospheric response to thermal forcing in the tropics for the observed southern hemisphere winter mean stationary waves and for several cases of anomalous quasi stationary waves in both the northern and southern hemispheres for the simple model the propagation of wave activity out of the tropics is clear from the observational data the apparent sources of anomalous stationary wave activity are located in the regions of the major middle latitude jets and storm tracks in both hemispheres in most cases the results suggest that midlatitude processes such as instabilities of the jet stream or interaction with transient eddies are the major mechanisms for forcing anomalous stationary waves there are indications that rossby like wave propagation from low latitudes plays a role in forcing anomalous stationary waves associated with southern oscillation ev

eclogites from the silvretta nappe switzerland geochemical constraints on the nature and geotectonic setting of their protoliths abstract in the austroalpine silvretta nappe of central europe eclogitic rocks of presumed paleozoic metamorphic age have recently been found their chemical composition suggests that they were derived from evolved tholeiitic magmas which have undergone variable degrees of fractionation at shallow depths involving crystallization of plagioclase plus olivine and or pyroxene the igneous protoliths probably originated at a constructive plate margin although some chemical features closely resemble those of mid ocean ridge basalts the composition of the metasedimentary country rocks suggests a tectonic setting close to a continental block perhaps in a back arc basin situation or incipient oceanic ridge

origin and assembly of the tethyside orogenic collage at the expense of gondwana land abstract the tethysides are a superorogenic complex flanking the eurasian continent to the south and consisting of the cimmerides and alpides products of palaeo and neo tethys respectively we here review their evolution mainly on the basis of new maps showing the distribution of sutures magmatic rocks certain palaeobiogeographically and palaeoclimatologically significant taxa and facies and fragments of pan african 900 450 ma orogenic system forming the basement of many tethyside blocks these are supplemented by palaeomagnetic data reported in the literature a fundamental tenet of this paper is that major sutures which contain ophiolite fragments represent tectonic sections between continental blocks where oceanic crust has been subducted palaeo tethys came into existence largely in late carboniferous time coevally it began to be consumed by both internal and peripheral subduction zones which continued into the permian some of these had been inherited from pre tethyan times in the later permian rifting subparallel with the northern margin of gondwana land began between the zagros and malaysia separating a cimmerian continent from n gondwana land and thus heralding the opening of neo tethys and other smaller oceans that were back arc basins of palaeo tethys this rifting possibly also extended farther west into crete and mainland greece however the north china block yangtze block huanan block the eastern moity of the qangtang block north tibet and annamia all originally pieces of the end proterozoic early palaeozoic gondwana land had already separated from it in pre late carboniferous times possibly during the devonian all of these blocks and the cimmerian continent were characterized by cathaysian floral elements in late palaeozoic time palaeomagnetic and palaeontological data showing the original gondwana land affinity of these continental blocks are supplemented by correlating late proterozoic early palaeozoic pan african sutures orogenic belts and sedimentary basin fragments across tethyside sutures late permian foraminiferal provinces are related to this palaeogeographical interpretation by triassic times most cimmeride subduction zones were already in existence the cimmerian continent accelerated its separation from gondwana land and locally in the late permian began disintegrating internally along the waser rushan pshart banggong co nu jiang mandalay ocean by late triassic time all of the chinese blocks except lhasa and annamia had collided with each other and with laurasia the resulting enormous orogenic collage had a soft cushion between itself and laurasia in the form of the enormous accretionary complex of the songpan ganzi this connection enabled laurasian land vertebrates to reach south east asia by late triassic time in late triassic to middle jurassic times most major cimmeride collisions were completed widespread aridity in central asia occurred in late jurassic time probably in the rain shadow of the newly formed cimmeride mountain wall neo tethyan subduction systems formed along the s margin of the cimmerides or within neo tethyan oceanic lithosphere during the jurassic most if not all were north or east dipping they continued the northerly migration of the tethyside blocks evolution of the tethysides influenced the distribution of marine and terrestrial organisms and affected sea level changes and patterns of atmospheric circulation during much of the mesozoic and cainozoic it is likely to have reflected the surface expression of a persistent trend in the large scale convective circulation in the mantle that continuously transported material northward into the tethyan domain

the association between stratospheric weak polar vortex events and cold air outbreaks in the northern hemisphere previous studies have identified an association between temperature anomalies in the northern hemisphere and the strength of stratospheric polar westerlies large regions in northern asia europe and north america have been found to cool during the mature and late stages of weak vortex events in the stratosphere a substantial part of the temperature changes are associated with changes in the northern annular mode nam and north atlantic oscillation nao pressure patterns in the troposphere the apparent coupling between the stratosphere and the troposphere may be of relevance for weather forecasting but only if the temporal and spatial nature of the coupling is known using 51 winters of re analysis data we show that the development of the lower tropospheric temperature relative to stratospheric weak polar vortex events goes through a series of well defined stages including the formation of geographically distinct cold air outbreaks at the inception of weak vortex events a precursor signal in the form of a strong high pressure anomaly over northwest eurasia is associated with long lived and robust cold anomalies over asia and europe a few weeks later near the mature stage of the weak vortex events a shorter lived cold anomaly emerges off the east coast of north america the probability of cold air outbreaks increases by more than 50 in one or more of these regions during all phases of the weak vortex events this shows that the stratospheric polar vortex contains information that can be used to enhance forecasts of cold air outbreaks as large changes in the frequency of extremes are involved this process is important for the medium range and seasonal prediction of extreme cold winter days three hundred year pre industrial control simulations by 13 coupled climate models corroborate our results copyright 2010 royal meteorological society and crown copyright

interdecadal variability of the warm arctic and cold eurasia pattern and its north atlantic origin abstractthis study investigates the origin of the interdecadal variability in the warm arctic and cold eurasia wace pattern which is defined as the second empirical orthogonal function of surface air temperature sat variability over eurasian continent in northern winter by analyzing the twentieth century reanalysis dataset while previous studies highlight recent enhancement of the wace pattern ascribing it to anthropogenic warming we found that the wace pattern has experienced a seemingly periodic interdecadal variation over the twentieth century this long term variation in the eurasian sat is attributable to the altered coupling between the siberian high sh and intraseasonal rossby wave emanating from the north atlantic as the local wave branch interacts with the sh and consequentially enhances the continental temperature perturbation it is further identified that these atmospheric circulation changes in eurasia are largely controlled by the decadal amplitude modulation of the climatological

timing of tectonic events in the menderes massif western turkey implications for tectonic evolution and evidence for pan african basement in turkey the menderes massif forms the western of the two large metamorphic culminations within the turkish alpide orogen it has three major lithologic units with a gneissic core at the base and a schist and a marble envelope overlying it successively although relations between them have been largely obscured by the polymetamorphic and structurally complex history of the massif we present a review of the available stratigraphic evidence and combine it with new isotopic ages from the central and southern parts of the massif to constrain the timing of major tectonic events that shaped the massif since the late proterozoic pt3 in the southern part of the massif sensu stricto three episodes of deformation and metamorphism are distinguished whereas in its northern part there are four the first episode occurred at 500 10 ma with intense deformation and metamorphism at high grade amphibolite facies with local anatexis in the central part of the massif the 470 9 ma old now highly deformed tonalitic and granitic intrusions mark the end of this episode on a cambrian reconstruction of continents around the eastern mediterranean the menderes massif forms the southern end of the pan african orogenic collage of northeastern africa and arabia the area of earliest palaeozoic deformation in the menderes may connect with the northwest african orogenic collage along the strike via the bozburun and saricicek diabases arkoses and schists in the center of the karacahisar dome interpreted herein as fragments of a pan african suture the earliest palaeozoic deformations to affect the rocks were probably related to the last pan african collisions and associated postcollisional convergence the southern part of the massif was undeformed from early ordovician to the early later eocene whereas the northern part was deformed metamorphosed and intruded possibly during the late triassic related to the closure of the karakaya marginal basin of palaeo tethys the next major event affecting the whole of the massif was the intense deformation and widespread metamorphism that reached high amphibolite grade in the structurally lower parts and only greenschist grade in the outermost envelope this metamorphism here called the main menderes metamorphism mmm is biostratigraphically constrained between early eocene and early oligocene time rb sr isotopic data show a spread of ages between 60 ma and 25 ma with the greatest number of determinations around 35 5 ma this number is in excellent agreement with the stratigraphic evidence and shows that mmm took place during latest eocene time or at the transition from eocene to oligocene time along the northern border of the massif deformation and metamorphism had already taken place during the late cretaceous in a high pressure low temperature hp lt metamorphic belt northernmost part of menderes massif sensu lato which was then covered by palaeocene molasse the evolution of the hp lt belt was probably related to the obduction of the bozkir ophiolites from the izmir ankara branch of the neo tethys ocean and preceded terminal collision in the evolution of the massif the mmm was a product of the latest palaeocene collision across neo tethys and the consequent internal imbrication of the menderes taurus block that resulted in the burial of the menderes massif area beneath the lycian nappe complex a low grade metamorphic event dated at 10 to 5 ma is interpreted to be related to the extensional deformation in the aegean and western turkey which has been dated stratigraphically to have begun during the tortonian 11 5 ma

extraction of geopotential height and temperature structure from profiler and rawinsonde winds mesoscale height and temperature fields can be extracted from the observed wind field by making use of the full divergence equation mass changes associated with irrotational ageostrophic motions are retained for a nearly complete description of the height field above the boundary layer in the absence of friction the divergence equation includes terms composed of the components of the wind and a laplacian of the geopotential height field once the mass field is determined the thermal structure is obtained through application of the hypsometric equation in this paper an error analysis of this divergence method is undertaken to estimate the potential magnitude of errors associated with random errors in the wind data previous applications of the divergence method have been refined in the following ways i the domain over which the method is applied is expanded to encompass the entire storm fest domain ii wind data from 23 profiler and 38 rawinsonde sites are combined in the analysis iii observed profiler and rawinsonde data are interpolated to grid points through a modified objective analysis and iv the variation in elevation of the profiler sites is taken into account the results of the application of the divergence method to the combined wind data from profiler and rawinsonde sites show good agreement between the retrieved heights and temperatures and the observed values at rawinsonde sites standard deviations of the difference between the retrieved and observed data lie well within the precision of the rawinsonde instruments the difference field shows features whose magnitude is significantly larger than the errors predicted by the error analysis and these features are systematic rather than random in nature suggesting that the retrieved fields are able to resolve mesoscale signatures not fully captured by the rawinsonde data alone the divergence method is also applied solely to the profiler data to demonstrate the potential of the divergence method to provide mass and thermal fields on a routine basis at synoptic times when operational rawinsonde data are not available a comparison of the heights derived from the profiler winds with those independently measured by rawinsondes indicates that valuable information on the evolution of atmospheric height and temperature fields can be retrieved between conventional rawinsonde release times through application of the divergence method the implications of the results for applications of the method in weather analysis and in numerical weather prediction are discussed

mechanisms of intraseasonal amplification of the cold siberian high mechanisms of intraseasonal amplification of the siberian high are investigated on the basis of composite anomaly evolution for its strongest events at each of the grid points over siberia at each location the amplification of the surface high is associated with formation of a blocking ridge in the upper troposphere over central and western siberia what may be called wave train atlantic origin type is common where a blocking ridge forms as a component of a quasi stationary rossby wave train propagating across the eurasian continent a cold air outbreak follows once anomalous surface cold air reaches the northeastern slope of the tibetan plateau it is found through the potential vorticity pv inversion technique that interaction between the upperlevel stationary rossby wave train and preexisting surface cold anomalies is essential for the strong amplification of the surface high upper level pv anomalies associated with the wave train reinforce the cold anticyclonic anomalies at the surface by inducing anomalous cold advection that counteracts the tendency of the thermal anomalies themselves to migrate eastward as surface thermal rossby waves the surface cold anomalies thus intensified in turn act to induce anomalous vorticity advection aloft that reinforces the blocking ridge and cyclonic anomalies downstream of it that constitute the propagating wave train the baroclinic development of the anomalies through this vertical coupling is manifested as a significant upward flux of wave activity emanating from the surface cold anomalies which may be interpreted as dissipative destabilization of the incoming external rossby waves

on the three dimensional propagation of stationary waves abstract a locally applicable nonzonally averaged conservation relation is derived for quasi geostrophic stationary waves on a zonal flow a generalization of the eliassen palm relation the flux which appears in this relation constitutes it is argued a useful diagnostic of the three dimensional propagation of stationary wave activity this is illustrated by application to a simple theoretical model of a forced rossby wave train and to a northern hemisphere winter climatology results of the latter procedure suggest that the major forcing of the stationary wave field derives from the orographic effects of the tibetan plateau and from nonorographic effects diabatic heating and or interaction with transient eddies in the western north atlantic and north pacific oceans and siberia no evidence is found in the data for wave trains of tropical origin forcing by the orographic effects of the rocky mountains seems to be of secondary importance

why might stratospheric sudden warmings occur with similar frequency in el nino and la nina winters 1 the effect of el nino southern oscillation enso on the frequency and character of northern hemisphere major mid winter stratospheric sudden warmings ssws is evaluated using a meteorological reanalysis data set and comprehensive chemistry climate models there is an apparent inconsistency between the impact of opposite phases of enso on the seasonal mean vortex and on ssws el nino leads to an anomalously warm and la nina leads to an anomalously cool seasonal mean polar stratospheric state but both phases of enso lead to an increased ssw frequency a resolution to this apparent paradox is here proposed the region in the north pacific most strongly associated with precursors of ssws is not strongly influenced by el nino and la nina teleconnections in the observational record both la nina and el nino lead to similar anomalies in the region associated with precursors of ssws and consistent with this there is a similar ssw frequency in la nina and el nino winters a similar correspondence between the penetration of enso teleconnections into the ssw precursor region and ssw frequency is found in the comprehensive chemistry climate models the inability of some of the models to capture the observed relationship between la nina and ssw frequency appears related to whether the modeled enso teleconnections result in extreme anomalies in the region most closely associated with ssws finally it is confirmed that the seasonal mean polar vortex response to enso is only weakly related to the relative frequency of ssws during el nino and la nina

the iapetus model a plate tectonic concept for the variscan belt of europe abstract a plate tectonic model is presented explaining the evolution of the variscan belt of europe it regards the iapetus ocean and its branch the tornquist sea as the only ocean involved in the caledonian variscan and alleghenian mega orogen the iapetus and its marginal basins disappeared through oblique subduction and collision in the following sequence 1 1 northeastern iapetus including the tornquist sea caledonian orogeny 2 2 central iapetus acadian orogeny 3 3 adjacent marginal basins variscan orogeny and 4 4 southwestern iapetus alleghenian orogeny the area of the variscides was part of the continental margin of gondwana made up of ridges and ensialic basins no ocean lay within the variscan area during the palaeozoic although patches of oceanic crust probably existed in rift basins e g the lizard ophiolite after the silurian early devonian closure of northwestern and central iapetus the variscan area was surrounded by cratons on three sides in a manner similar to that around the modern mediterranean sea the subsequent variscan orogeny was essentially an ensialic thrusting and folding induced by a further approach of gondwana toward laurentia after the variscan collision gondwana rotated clockwise to the west by moving along a strike slip zone this rotation during the carboniferous opened the palaeo tethys in the east and caused the alleghenian collision in the west the middle ordovician to permian palaeogeography is presented on a series of maps modelling tectonic displacement and plate motions avalonia is interpreted as the ordovician volcanic island arc of gondwana separated from mainland gondwana by an oceanic gulf or a back arc basin the iberian arc may have originated by a continental escape of iberia from the center of collision into the oceanic gulf the variscan austro alpine and southern alpine units are today located near their earliest early carboniferous position

strain partitioning across a fold and thrust belt the rhenish massif mid european variscides abstract strain data across the entire western rhenish massif illustrate the pattern of deformation partitioning within a fold and thrust belt from the foreland on the northern front of the european variscides to the suture with the internal zones of higher metamorphic grade shortening perpendicular to cleavage increases from 16 to 27 constant volume assumed in the northern rhenish massif to 51 at the southern border these values correspond to a weak general layer parallel shortening of the basin filling in cross section on the order of about 5 15 and more in the case of volume loss the geometry of apparent finite strain is nearly plane strain except in the venn anticlinorium where strain is apparent prolate and near the southern margin of the massif where it is apparent oblate net orogenic shortening in the upper crust of the fold and thrust belt is approximately 42 it is mainly achieved by folding and tectonic stacking of the deformed basin filling which was apparently detached from the lower crust distribution of strain in the orogenic wedge is controlled by different factors at different scales heterogeneity is caused by changes in lithology and average grain size by the structural position of samples in folds and their distance from thrusts in the hangingwall at deeper crustal levels and by the regional distribution of the metamorphic grade i e by the dominant deformation mechanism this last factor causes an exponential increase of strain with approach to the ductile lower crust the superposition of strain partitioning mechanisms on different scales creates a complex regional strain pattern the southern part of the thrust belt apparently suffered late westward motion in gently dipping imbricates or strike parallel motion in steeply dipping imbricates which is probably due to oblique convergence between the rhenohercynian and saxothuringian microplates

formation mechanisms of the pacific north american teleconnection with and without its canonical tropical convection pattern abstractthe mechanisms that drive the pacific north american pna teleconnection pattern with and without its canonical tropical convection pattern are investigated with daily era interim and noaa olr data the former pattern is referred to as the convective pna and the latter pattern is referred to as the nonconvective pna both the convective and nonconvective positive pna are found to be preceded by wave activity fluxes associated with a eurasian wave train these wave activity fluxes enter the central subtropical pacific a location that is favorable for barotropic wave amplification just prior to the rapid growth of the pna the wave activity fluxes are stronger for the positive nonconvective pna suggesting that barotropic amplification plays a greater role in its development the negative convective pna is also preceded by a eurasian wave train whereas the negative nonconvective pna grows from the north pacific contribution to a circumglobal teleconnection pattern driving by high frequency ed

vertically integrated sensible heat budgets for stable nocturnal boundary layers summary the stable nocturnal boundary layer is commonly viewed or modelled as a balance between the temperature tendency cooling and vertical heat flux divergence sometimes the radiative flux divergence is also included this perspective has dictated the design of field experiments for investigating stable nocturnal boundary layers tower based micrometeorological data from three field campaigns are analysed to evaluate the vertically integrated sensible heat budget for nocturnal stable conditions our analysis indicates frequent occurrence of large imbalance between the temperature tendency and vertical heat flux divergence terms the values of the radiative flux divergence are generally too small and sometimes of the wrong sign to explain the residual an analysis of random flux errors and uncertainties in the tendency term indicate that such errors cannot explain large imbalances suggesting the importance of advection of temperature or possibly the divergence of mesoscale fluxes the implied role of advection is consistent with circumstantial evidence even weak surface heterogeneity can create significant horizontal gradients in stable boundary layers however it is shown that existing field data and observational strategy do not allow adequate evaluation of advection and mesoscale flux divergence terms

towards a southern european tethyan palaeomargin provenance signature sandstone detrital modes and detrital zircon u pb age distribution of the upper cretaceous paleocene monte bignone sandstones ligurian alps nw italy constraining the source terranes of alpine siliciclastic flysch sequences is crucial for building a clearer picture of the palaeogeography and geodynamic evolution of the western tethys in the framework of impending continental collision this paper presents an integrated study that involves palaeocurrent dispersal analysis sandstone petrography and detrital zircon geochronology of the upper cretaceous paleocene monte bignone sandstones a siliciclastic turbidite system deposited during the pre collisional evolution of the ligurian alps palaeocurrent analysis illustrates an overall eastward transport of the proximal sediments in the present configuration considering the ca 45 50 counter clockwise rotation of the tertiary piedmont basin and of the corsica sardinia block in the late paleogene this indicates the derivation of the sediments from the northern margin of the piedmont ligurian ocean sandstone petrography records a stratigraphic evolution from quartzose sandstones towards lithic and then to lithic sub arkosic composition this trend is interpreted to reflect the gradual unroofing of the provenance terrane the lithotypes of the recycled sedimentary rock fragments and the up section increase in dolostone and carbonate clast proportions suggest the erosion of the sedimentary cover of the southern european palaeo margin new geochronological data u pb detrital zircon ages correspond to the pre alpine stages of crustal growth recorded in the variscan maures tanneron massif and therewith confirm the derivation of the sediments from the passive palaeo european margin this conclusion highlights the importance of the lower plate in providing the source of coarse clastic deep water successions during pre collisional convergent steps results from this multi proxy provenance analysis contribute to better defining the detrital signatures associated to the continental micro fragments that constituted the palaeo european plate as it supplied deep sea siliciclastic sediments into the piedmont ligurian ocean prior to continental collision

space and time in the tectonic evolution of the northwestern iberian massif implications for the variscan belt recent advances in geochemical studies of igneous rocks isotopic age data for magmatism and metamorphism quantitative pressure temperature p t estimates of metamorphic evolution and structural geology in the northwestern iberian massif are integrated into a synthesis of the tectonic evolution that places the autochthonous

the diagnosis of upper tropospheric divergence and ageostrophic wind using profiler wind observations abstract wind fields derived from a network of three vhf doppler radars are used to calculate the mean kinematic properties of the wind field over colorado and an area averaged geostrophic and ageostrophic wind a numerical technique that is equivalent to the line integral method is used to compute the kinematic quantities details of this technique termed the linear vector point function method lvpf are discussed the behavior of the vorticity divergence deformation geostrophic wind and ageostrophic wind are examined for two case studies when the synoptic scale weather patterns over colorado are dominated by moderately intense upper level troughs and jet streams we find that the computed quantities of divergence absolute vorticity deformation geostrophic and ageostrophic wind are modified by the passage of the weather systems in a manner consistent with our present understanding of upper level dynamics in addition temporal variations in the kinematic properties geostrophic wind and ageostrop

a non cylindrical model for the northwest iberian allochthonous terranes and their equivalents in the hercynian belt of western europe abstract a case is made for a non cylindrical development of the european hercynian belt far travelled allochthonous terranes in the belt consist of a mixture of units including catazonal units ophiolites and units derived from the continental margin of gondwana they often depict a metamorphic history of intermediate to high pressure type and caledonian to eo hercynian age and are thought to have been put together in the early stages of the orogeny through a process partly obductive directed onto the continental margin of gondwana considerations upon the disposition of the terranes their relationships with the paleogeography of the gondwana realm and the structures in them suggest that their emplacement took place in an oblique fashion at a small angle to the margin of the continent the proposed allochthon could be related to the development of an island arc or a wedge like subplate in the southern part of the baltica plate later convergence between gondwana and laurussia involving transcurrent mostly dextral movements combined with tectonic escape phenomena would account for the present complexity of the belt and for the narrow strip the allochthonous terranes delineate in westernmost europe

the ghomarides nappes rif coastal range morocco a variscan chip in the alpine belt the ghomarides nappes are the uppermost basement nappes in the rifan alpine belt paleozoic rocks constitute the prominent part of these nappes together with triassic and younger cover sediments four nappes are distinguished each one with a distinct stratigraphical sequence especially for the devonian and carboniferous periods sedimentological and structural arguments plead for an initial location on the northern margin of the african continent the main folding and metamorphic events are shown to be eo variscan late acadian tectonic vergence was to the north present coordinates late variscan hercynian shortening gave upright nw se trending folds alpine ductile overprints are scarce except at the base of the lowest nappe where k ar phengite ages are about 25 ma the ghomarides nappes correlate with the malaguides nappes betic cordilleras southern spain the kabylian northern algeria and calabrian southern italy paleozoic nappes the tuscan south alpine basement and the upper austro alpine nappes the proposed correlations allow us to restaure the southern margin of the hercynian belt along northwestern africa

eclogites of paleozoic or early alpine age in the basement of the penninic siviez mischabel nappe wallis switzerland outcrops of eclogites and retroeclogites occur in the normal limb of the siviez mischabel fold nappe penninic alps wallis switzerland the ecologites are contained in the gneisses of the ergischhorn and barneuza units turtmanntal and val de moiry where they usually associate with banded amphibolites high pressure mineral assemblages in the eclogites pyrope rich almandine and omphacite are overprinted by later amphibolite and greenschist facies metamorphic minerals according to coleman s classification the eclogites belong to the b type with pt values around 650 c for a minimum pressure of 15 kb geochemical investigations suggest a tholeiitic basalt affinity some problems still remain to solve these are 1 the geodynamic contexts and 2 the age of the eclogite facies overprint whether alpine or pre alpine in the absence of radiometric ages the following arguments favour a pre alpine lower paleozoic or older age of the high pressure metamorphism 1 1 the presence of polymetamorphic paragenesis the eclogitic mineral assemblages being the oldest 2 2 the b type of the eclogites which are associated tectonically with polymetamorphic gneisses 3 3 the presence in the same tectonic units of permian gabbros which show no signs of eclogite facies overprint 4 4 the presence of autochthonous sedimentary cover rocks that have been dated triassic to eocene this makes it difficult to assume an eo alpine cretaceous subduction of the underlying basement 5 5 the existence of striking similarity with other pre alpine eclogites related to a lower paleozoic 500 460 ma high pressure event well documented in some alpine and extra alpine basement units it could have associated with a caledonian subduction of oceanic crust

transient eddy forcing of the time mean flow as identified by geopotential tendencies abstract the forcing of the time mean flow by transient eddies is examined within the framework of a quasi geostrophic equation relating the geopotential tendency to the convergence of transient eddy transports of heat and vorticity the forcing functions of this equation are computed using observed circulation statistics for the wintertime northern hemisphere and solutions are sought for the three dimensional structure of geopotential and temperature tendencies associated with eddies of different time scales in general the geopotential tendencies associated with vorticity fluxes are of the same sign within a given atmospheric column whereas the polarity of the geopotential tendencies associated with heat fluxes in the lower troposphere is opposite to that in the upper troposphere the geostrophic wind tendencies associated with synoptic scale eddies with periods between 2 5 and 6 days are strongest in the vicinity of the oceanic storm tracks the enhanced poleward heat transports by active disturbanc

sedimentological response to late mesozoic subduction in the penninic windows of the eastern alps late mesozoic subduction of penninic oceanic lithosphere finds its response in the sedimentary record the corresponding sediments are deposited in a deep sea trench environment and are developed as distal partly proximal flysches containing breccias and olistolites which are up to kilometer sized wildflysch in the tauern window this facies is represented by the nordrahmen zone which is the equivalent to the matrei zone it is proposed to apply the term matrei zone to the entire zone it forms the high parts of the bundner schiefer and tauernflysch formation the olistolites derive from the unstable austroalpine continental margin lower austroalpine

lower palaeozoic volcanism of the eastern alps and its geodynamic implications a geodynamic model for the lower palaeozoic evolution of the eastern alps upper ordovician to middle devonian gurktal nappe styrian greywacke zone palaeozoic of graz is discussed based on new field work and numerous geochemical analyses of volcanic rocks it is suggested that in the upper ordovician there existed on the one hand a passive continental margin or continental rift flooded by the sea where mildly alkaline basalts erupted magdalensberg series carinthia kaser series gurktaler alpen on the other hand a convergent plate boundary in the form of an active continental margin or island arc or in the form of an orogen formed by continent continent collision which can be recognized by the eruption of calc alkaline volcanic rocks probably also existed in the upper ordovician blasseneck porphyroid styrian greywacke zone nockseries gurktaler alpen in the lower silurian a reorganization of the plate boundaries took place resulting in the disintegration of the upper ordovician collision zone along deep reaching faults further extensional movements during the silurian and devonian led to the disintegration of a broad shelf platform and to the eruption of alkaline within plate basalts the extensional movements were responsible for the thinning of the continental crust and a general subsidence which probably lasted until lower carboniferous time

solid inclusions in chrome spinels and platinum group element concentrations from the hochgrossen and kraubath ultramafic massifs austria a great variety of platinum group mineral sulfide and silicate inclusions in chrome spinel from hochgrossen and kraubath ultramafic massifs and platinum group element contents of three different rock types have been investigated both ultramafic massifs are tectonically isolated bodies variably serpentinized and metamorphosed greenschist to lower amphibolite facies and show ophiolitic geochemical affinities the chromite from massive chromitites and disseminated in serpentinized dunites and serpentinites exhibits compositional zonation as the result of alteration during serpentinization and metamorphism three distinctive alteration stages are indicated in the chrome spinels from the hochgrossen whereas alteration is less significant in chromites from kraubath the core of chrome spinel represents the least altered part surrounded by an inner rim characterized by slight compositional differences in cr mn fe2 and al with respect to the core the outer rim is formed by ferritchromite with a sharp boundary to the inner rim and shows a significant decrease of al mg cr and increase of fe2 fe3 and ni compared to the core two different groups of inclusions in chrome spinel are present the first group occurs within the chromite core and comprises olivine orthopyroxene amphibole sulfides and platinum group minerals i e dominated by ru os ir sulfides the second group is formed by chlorite serpentine galena pyrite arsenopyrite pt pd rh dominated sulfarsenides and sperrylite in particular the abundance of pt pd rh sulfarsenides and arsenides is typical of both ultramafic massifs and is very unusual for chromitites from ophiolites morphology paragenesis and chemical composition indicate a different origin for these two groups of inclusions the first group is intimately related to the crystallisation of the chromite host the second group of inclusions clearly displays a secondary formation during serpentinization and metamorphism closely related to the alteration of chrome spinel and the development of ferritchromite the distribution patterns of the platinum group elements from massive chromitites disseminated chrome spinel bearing serpentinites and serpentinites exhibit variable enrichment of rh pt and pd rh pt for the hochgrossen and kraubath massifs respectively these results are in accordance with the occurrence and distribution of platinum group mineral phases a remobilisation of pt pd and rh together with ni cu and possibly fe as bisulfide and or hydroxide complexes and deposition of metals by the reaction of the metal bearing hydrothermal fluid with chromite is proposed

u pb dating of an early paleozoic bimodal magmatism in the french massif central and of its further metamorphic evolution in the marvejols area southern french massif central the gneissic marvejols supergroup is overthrust on the metasedimentary serie du lot deposited in part prior to 540 ma the allochtonous terranes are characterized by the occurrence of a leptyno amphibolitic group a complex association of mafic and felsic rocks of igneous and sedimentary derivation a 480 10 ma age has been obtained by u pb dating of zircons for the crystallization of both mafic and felsic meta igneous rocks these rocks were emplaced during an important extensional tectonics relics of eclogites pyrigarnites coronite gabbros and hp trondhjemites are clear evidence for a further hp ht event dated at 415 6 ma on zircons from a hp trondhjemite subsequently the marvejols supergroup underwent an amphibolite facies metamorphism with incipient mobilization dated at 345 10 ma

neoproterozoic to early palaeozoic magmatic evolution in the gondwana derived austroalpine basement to the south of the tauern window eastern alps in the austroalpine basement to the south of the tauern window distinct suites of metabasites occur with orthogneisses in pre early ordovician units tholeiitic and alkaline within plate basalt type metabasites are associated with acid meta porphyroids in the post early ordovician thurntaler phyllite group according to their correlated trace element abundances metabasite zircons crystallized with their host rocks protolith pb pb zircon ages whole rock ta yb th yb and oxygen sr nd isotope data define two principal evolution lines an older evolution at elevated th yb typical of subduction related magmatism started by 590 ma n morb type and 550 530 ma volcanic arc basalt type basic suites which mainly involved depleted mantle sources it finished with mainly crustal source 470 450 ma acid magmatites an other evolution line by tholeiitic and 430 ma alkaline within plate basalt type suites in both pre and post early ordovician units is characterized by an intraplate mantle metasomatism and enrichment trend along multicomponent sources these magmatic evolution lines can be related to a plate tectonic scenario that involved terranes in a progressively mature neoproterozoic to ordovician active margin and a subsequent palaeo tethys passive margin along the north gondwanan periphery

two types of the scandinavian pattern their formation mechanisms and climate impacts abstracton the basis of daily data from the japanese 55 year reanalysis jra 55 for extended winters december march from 1958 59 to 2014 15 this study examines the formation mechanisms and clim

40ar 39ar dating of the inner carpathians variscan basement and alpine mylonitic overprinting abstract the 40ar 39ar dating method has been applied to mylonitic rocks from the carpathian mountains these are variscan metamorphic and magmatic rocks that were overprinted during the alpine orogeny the inner western carpathians are conventionally described as a nappe pile formed by northward movement and then subjected to intense strike slip and normal faulting resulting in the formation of mylonitic rocks precise stratigraphie ages provide clear constraints for the geodynamic interpretation related to the succession of alpine events such as the pre gosauian phase during the turonian 90 ma the 40ar 39ar method allows to define the age of the ancient variscan basement and the ages of the alpine overprinting in the high and low tatras mineral ages of around 340 350 ma are yielded by gneisses micaschists and amphibolites providing a younger limit for the variscan metamorphism the emplacement cooling of the variscan granites is defined between 305 and 335 ma these rocks are overprinted by several alpine tectonothermal events the major events are dated at 65 and 86 88 ma during which the mylonites were generated an older event around 140 ma earlier defined by the rb sr method is now confirmed by the 40ar 39ar method dating of phengites extracted from high pressure metamorphic triassic rocks from the kosice area yields new data for the age of this event at 155 ma