cambro ordovician anatexis and magmatic recycling at the thinned gondwana margin new constraints from the kouřim unit bohemian massif the kou im unit represents one of the largest pre variscan meta igneous complexes in the bohemian massif and a geochronological whole rock geochemical and sr nd isotopic study was conducted to better understand the magmatic evolution of the early paleozoic gondwana margin five orthogneisses yield u pb zircon ages ranging from 492 4 to 484 2 ma two leucogranites give u pb zircon ages of 500 4 and 485 2 ma interpreted to be inherited from their orthogneiss host rock two samples from the metasedimentary host rock are dominated by neoproterozoic cambrian detrital zircons the abundance of zircon inheritance in the orthogneisses and whole rock sr nd isotopic composition imply an origin from relatively mature continental crustal material the subalkaline subaluminous slightly peraluminous and high k calc alkaline arc like geochemical signature of the orthogneisses is interpreted as inherited from the recycled cadomian metasedimentary source and both the magmatic and metasedimentary rocks are correlated with similar occurrences in the adjacent moldanubicum and tepla barrandian unit the late cambrian early ordovician magmatic activity is linked to crustal anatexis which was probably initiated by thermal and gravitational relaxation of the thickened cadomian arc type crust followed by lithospheric thinning assisted by far field forces the extensional event led to the formation of a passive margin associated with the opening of the rheic ocean supplementary material analytical methods petrographic descriptions with photographs of studied samples collections of cl images of representative zircon grains results of la icp ms u pb analyses of zircons and an additional geochemical diagram are available at https doi org 10 6084 m9 figshare c 4649255

a new multiscale model for the madden julian oscillation abstract a multiscale model of the mjo is developed here that accounts in a simplified fashion for both the upscale transfer from synoptic to planetary scales of momentum and temperature from wave trains of thermally driven equatorial synoptic scale circulations in a moving convective envelope as well as direct mean heating on planetary scales this model involves idealized thermally driven congestus synoptic scale fluctuations in the eastern part of the moving wave envelope and convective superclusters in the western part of the envelope the model self consistently reproduces qualitatively many of the detailed structural features of the planetary circulation in the observations of the mjo including the vertical structure in both the westerly onset region and the strong westerly wind burst region as well as the horizontal quadrupole planetary vortex structure the westerly midlevel inflow in the strong westerly region and the quadrupole vortex are largely produced in the model by the upscale transpor

unexpected peak near 15 c in cloudsat echo top climatology 1 we examine a radar derived climatology of earth s cloudiness focusing on the vertical distribution echo tops between the two main peaks at 2 km and 14 km associated with low and high clouds respectively lie two distinct midlevel peaks in the tropics one is in the 5 6 km layer the other between 7 and 8 km both are seen day and night over land and sea over each tropical ocean basin and in published ground radar climatology in the extratropics the vertical echo top distribution by temperature reveals a strikingly sharp peak in the 15 to 20 c layer corresponding to the 7 8 km peak in the tropics again the signal is robust night day land sea summer winter we consider interpretations of the 15 c peak ranging from data artifacts unlikely to mere radar brightening to possible true microphysical or dynamical cloudiness enhancement mechanisms

variscan tectonics of central europe postaccretionary intraplate deformation of weak continental lithosphere the area occupied by the variscan belt of central europe forms part of gondwana derived microplates essentially avalonia and armorica that according to paleomagnetic data juxtaposed baltica and laurentia from the upper ordovician to the lower devonian the actual structure of this area is a puzzle of rather small fault bounded crustal blocks different in p t t histories which was created by later tectonic processes at around 360 to 320 ma according to a common view and by contrast to paleomagnetic data the structural record of fault bounded blocks is interpreted in terms of mid devonian to lower carboniferous amalgamation of narrow continental plates represented by the fault bounded blocks themselves however this is not supported in this article instead it will be shown that fault systems and fault bounded blocks were created by intraplate deformation of a weak domain of gondwana derived continental lithosphere significantly after its accretion deformation was partitioned into newly formed deep seated strike slip and kinematically connected reverse or normal detachment systems large translation magnitudes caused juxtaposition of crustal areas of variable thickness until they were emplaced along the fault systems the various categories of fault bounded complexes record different tectonic events category 1 metamorphic complexes represent deep seated parts of thickened crust some time before unroofing on the detachment systems between about 340 360 and 320 ma however the record of subduction and extreme crustal thickening during earlier stages of the collision history was erased to a high degree and is only preserved by mineral and structural relics strike slip and detachment systems propagated across and dismembered tectonic boundaries formed during these early events category 2 metamorphic complexes and the barrandian basin recording predominant pre late devonian metamorphic or stratigraphic events represent the brittle upper crustal parts during continuing metamorphism in the category 1 complexes weakly or unmetamorphosed lower paleozoic category 3 basins represent areas of thinned continental crust and record subsidence before and to some degree during activity of detachment systems the complex overall kinematic pattern of block bounding strike slip and detachment systems indicates compression and extension acting simultaneously this probably reflects the effects of continuing oblique plate convergence rotation and wsw extrusion of fault bounded blocks in addition to heating and extensional flow of previously thickened crustal areas

eclogite facies rocks of the monotonous unit clue to variscan suture in the moldanubian zone bohemian massif abstract the formation and exhumation of variscan high to ultrahigh pressure metamorphic rocks from the moldanubian zone in the bohemian massif are the subject of controversy regarding their unclear relationship to possible subduction zones in this paper we present the results of a petrological study of eclogites that occur together with serpentinites within amphibolite facies gneisses in the moldanubian zone east of the tepla barrandian block more than 100 bodies of retrogressed eclogite and serpentinite follow an approximately 250 km long sw ne trending zone in the central part of the bohemian massif together with surrounding gneisses the eclogites share a medium to low pressure amphibolite facies metamorphism p t conditions estimated for the eclogite facies stage indicate a relatively low temperature geothermal gradient similar to those observed in the saxothuringian zone which occurs north and northwest of the tepla barrandian block the presence and distribution of eclogites and comparison of their p t and age data with hp uhpm rocks in other units in the bohemian massif allow us to constrain the variscan suture which straddles the se of the tepla barrandian block the existence of this suture in relation to available geotectonic models and its possible continuation through other allochthonous units along the european variscan belt are discussed

spatial analysis of fluoride concentration in groundwaters of shivani watershed area karnataka state south india through geospatial information system hydrogeochemical investigations with emphasis on groundwater fluoride concentrations were carried out in the shivani watershed area karnataka south india this drought prone watershed is characterised by poor groundwater potential and is composed of different lithounits like gneisses migmatites tonalites mafics ultramafics conglomerates and quartzites analysis of spatial variation of groundwater fluoride concentration through the use of gis technology software platforms like arcview 3 2a and mapinfo professional 8 5 has enabled the identification of low fluoride and high fluoride areas within the watershed geochemical data indicates that 38 of groundwater samples have excessive fluoride concentration which poses a health risk to the population of the area correlation studies indicate that higher groundwater alkalinity activates leaching of fluoride resulting in elevated concentrations of fluoride no other significant geochemical interrelationship could be identified between fluoride and rest of the physico chemical parameters owing to the lack of any significant correlation coefficients this holds good in the case of both low fluoride 1 5 mg l groundwaters of the watershed however differential or non uniform type positive or negative of coefficient of correlation is observed between fluoride at different levels and other physico chemical parameters among the different lithounits of the study area gneisses house comparatively more number of high fluoride groundwaters fluoride bearing minerals biotite hornblende and apatite are the probable natural sources of groundwater fluoride

zonal and vertical structure of the madden julian oscillation abstract a statistical study of the three dimensional structure of the madden julian oscillation mjo is carried out by projecting dynamical fields from reanalysis and radiosonde data onto space time filtered outgoing longwave radiation olr data mjo convection is generally preceded by low level convergence and upward motion in the lower troposphere while subsidence cooling and drying prevail aloft this leads to moistening of the boundary layer and the development of shallow convection followed by a gradual and then more rapid lofting of moisture into the middle troposphere at the onset of deep convection after the passage of the heaviest rainfall a westerly wind burst region is accompanied by stratiform precipitation where lower tropospheric subsidence and drying coincide with continuing upper tropospheric upward motion the evolution of the heating field leads to a temperature structure that favors the growth of the mjo the analysis also reveals distinct differences in the vertical structure

prograde metamorphism and decompression of the gfohl gneiss czech republic quartzofeldspathic rocks of the gfohl gneiss from the moldanubian of the czech republic span amphibolite to granulite facies and are associated with eclogite protomylonitic fabrics related to terminal tectonic emplacement and reworking of the gneiss are common some non mylonitic rocks however preserve early prograde features e g opx rimmed hbl in metabasites whereas others have characteristics generally associated with near isothermal decompression e g pl opx moats separating grt and qtz in metabasites crd spl coronas on grt and aluminosilicates in metapelites the unequivocal distinction between prograde and decompressional features in these rocks however may not be possible or even justified for example some metapelites contain growth zoned i e rimward increase in xmg garnets that also record evidence i e rimward decrease in xca compensated by the presence of reversely zoned plagioclase in the same rock of decompression in rare instances eclogitic rocks p 11 kbar interpreted as tectonic enclaves within the gneiss also record mineralogic evidence of decompression e g crd opx spr coronas on pyrope in metapelites plagioclase cored coronal garnets with high prpgrs ratios 2 5 record near isobaric cooling from near the thermal maximum at a relatively shallow but undetermined crustal level unlike gfohl gneisses elsewhere e g in austria the rocks described here do not preserve evidence of extreme metamorphic conditions texturally stable grt bt pairs in non mylonitic samples give tmax 750 c pmax is not known but prograde metamorphism apparently progressed from the kyanite to sillimanite fields implying p 8 kbar at the maximum grt bt temperature at these conditions dehydration of mafic gneiss occurred in the presence of a co2 rich xco2 0 85 pore fluid

transition from island arc to passive setting on the continental margin of gondwana u pb zircon dating of neoproterozoic metaconglomerates from the se margin of the tepla barrandian unit bohemian massif abstract sedimentological petrological and geochemical data combined with shrimp and la icp ms u pb ages of pebbles of granitic rocks and detrital zircons from neoproterozoic vletice metaconglomerates of the se margin of the tepla barrandian unit were used to characterize the regional geotectonic setting at the proterozoic paleozoic boundary the metaconglomerates form several metres thick intercalations in metasediments of the svrchnice formation roof pendants of central bohemian plutonic complex which is considered to have been deposited in neoproterozoic cambrian times a sedimentological study indicates that the metaconglomerates are products of debris flows deposited in submarine canyons or proximal parts of submarine fans geochemistry of metaconglomerate matrix and petrography of pebbles revealed an obvious difference from the western and central part of the tepla barrandian unit proterozoic where pebbles eroded from uplifted parts of the basin and island arc sources are most common the abundance of quartz quartzite granite and crystalline limestone in pebbles together with the more mature composition of host metagreywackes indicate the presence of relatively evolved continental crust in the source area for the vletice metaconglomerates and shallowing of the neoproterozoic basin to the se in the present geographic co ordinate system the neoproterozoic to lowermost cambrian age of the svrchnice formation suggested by its comparison with similar rocks in the central part of the tepla barrandian unit was confirmed by u pb dating ages of detrital zircons from the metaconglomerate matrix cluster around two values archaean to paleoproterozoic u pb ages between ca 2580 and 1780 ma and neoproterozoic to early cambrian ages between 660 and 520 ma with a significant peaks at 600 and 544 ma suggesting local volcanic activity extending shortly beyond the proterozoic paleozoic boundary zircons separated from two trondhjemite pebbles from the metaconglomerate yielded a mean u pb age of 610 17 ma arguing for active arc magmatism during the latest neoproterozoic the overall age distribution of detrital zircons and the absence of grenvillian zircon ages favour a location of the tepla barrandian unit close to the west african craton at the neoproterozoic paleozoic boundary the rapid onset of a transtensional geotectonic regime and maturing of sediments is evidenced by the overlying cambrian shallow water clastics alternating with predominantly felsic calc alkaline to alkaline volcanics during the cambrian oblique plate convergence the active continental margin was transformed into belts of horsts and narrow pull apart or small rift basins after the ordovician break off of armorican terrane assemblage blocks from gondwana the extensional regime in the tepla barrandian unit continued until the beginning of variscan orogeny in the middle devonian

a climatology of midlatitude mesoscale convective vortices in the rapid update cycle abstract climatological characteristics of mesoscale convective vortices mcvs occurring in the state of oklahoma during the late spring and summer of four years are investigated the mcv cases are selected based on vortex detection by an objective algorithm operating on analyses from the rapid update cycle ruc model consistent with a previous study true mcvs represent only about 20 of the mesoscale relative vorticity maxima detected by the algorithm the mcvs have a broad range of radii and intensities and their longevities range between 1 and 54 h their median radius is about 200 km and their median midlevel relative vorticity is 1 2 10 4 s 1 there appears to be no significant relationship between mcv longevity and intensity similar to past estimates approximately 40 of the mcvs generate secondary convection within their circulations the mean synoptic scale mcv environment is determined by the use of a ruc based composite analysis at four different stages in the mcv life cycle defined b

association of hydrogeological factors in temporal variations of fluoride concentration in a crystalline aquifer in india the major part of groundwater in india is found in granitic aquifers fluoride in groundwater from a crystalline aquifer in a semi arid region of granitic rocks in india known as maheshwaram watershed was analyzed for spatial and temporal variability during 1999 2002 to assess the effect of hydrogeological factors on fluoride concentration samples were collected from 32 representative wells in the area for the pre and post monsoon seasons and analyzed for f content the chess computer program was used to calculate ionic activities of aqueous species and the mineral saturation index si for calcite and fluorite the gardenia computer program was used to calculate the recharge values in the study area the influences of dissolution kinetics of fluoride minerals and recharge from rainfall on fluoride concentration were of interest and results clearly indicate that fluoride content in groundwater depends on the interaction period of groundwater with host rock results could also be utilized for designing remedial measures particularly with dilution method in an optimal way

occurrence and hydrogeochemistry of fluoride in alluvial aquifer of weihe river china fluoride f has significant impacts on human health high fluoride groundwater up to 1 90 mg l has been found in upper confined aquifer underlying the first terrace of weihe river during a hydrogeological investigation for water supply in 2005 to reveal the occurrence and hydrogeochemistry of high f groundwater hydrogeochemical tools such as saturation index ionic ratios and correlation analysis were used in this study the study shows that the concentrations of most physiochemical parameters from phreatic water influenced by intensive evaporation and anthropogenic activities such as unregulated sewage and excreta disposal and agricultural practices in the area are higher than those of confined water the f concentration in phreatic water is within the acceptable limits set by china and the world health organization who while that of upper confined water shows a decreasing trend northwestward as the weihe river approaches with f concentration in the first terrace beyond the national and the who standards high f groundwater is observed in alkaline environment associated with high na ph hco3 and low ca2 and mg2 the enrichment of f is controlled by geologic and hydrogeological conditions fluorine bearing minerals presented in alluvial formations and their dissolution precipitation under the alkaline environment along groundwater flow ion exchange human activities and the mixing of different recharge waters may influence the enrichment of f as well

role of gravity waves in triggering deep convection during toga coare the role of gravity waves in the initiation of convection over oceanic regions during the tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare experiment is investigated first an autocorrelation method is applied to infrared temperature observations of convective events from satellite images it reveals that new deep convective cells often occur a few hours after a previous intense event at a typical distance of a few hundred kilometers such fast moving modes faster than 15 m s 21 are interpreted as the trace of gravity waves excited by previous convection and contributing to trigger further convection second the specific case of 11 12 december 1992 during which an active squall line is generated after the collapse of a previous mesoscale convective system mcs nearby is analyzed with a nonhydrostatic model the triggering of the second mcs is well reproduced explicitly owing to the use of the two way interactive grid nesting the convective source appears to emit pulses of gravity waves on a wide range of small scales on the contrary the troposphere response to the convective source exhibits a spectral simplicity a slowly evolving mode characterized by an ascent in the pbl and a compensating subsidence in the free troposphere favors shallow convection and inhibits deep convection respectively traveling modes propagating away from the convective source are characterized by a fast mode 50 m s21 and a slower mode 25 ms 21 associated with the convective and stratiform development of the source respectively in agreement with previous studies a budget analysis reveals the different factors leading to the deep convection triggering first an active pbl characterized by strong surface fluxes and mean ascent initiates shallow convection lasting about 2 h inhibited above by the subsiding motions maintaining a dry layer second horizontal advection of moist and cooler air at midlevels and detrainment from cumuli contribute to destroy the dry air layer capping the shallow convective layer finally vertical advection induced by the gravity waves passage modulates the vapor and temperature evolution ascending phases favor moistening and cooling whereas subsiding phases stop these effects delaying the deep convection onset the triggering occurs after a strong subsidence when the ascent phases of deep and shallow modes are combined

coherent synoptic disturbances in the australian monsoon abstractcoherent synoptic scale weather systems within the australian monsoon are identified and tracked in the isentropic potential vorticity pv field from the ecmwf interim reanalysis era interim dataset during the southern hemisphere summer the resulting dataset is then used to compile statistics and synoptic composites of australian monsoon disturbances on average a synoptic system is found in the region every 2 5 days however the time interval between consecutive events is highly variable meaning that the synoptic activity in the australian monsoon is not well represented by commonly employed spectral techniques the analysis reveals that most synoptic systems originate within the australian monsoon but at the 315 k level approximately 700 hpa a significant proportion of systems are first detected near the east coast of the continent where extratropical rossby waves are observed to frequently break the average australian monsoon weather system propagates from east to west at approximatel

properties of deep convection in tropical continental monsoon and oceanic rainfall regimes 1 this study compares vertical structures and properties of deep convection for continental monsoonal and oceanic rainfall regimes based on 13 yr trmm measurements there is evident regime separation in convective structures and properties of deep convection continental and oceanic regimes are at two ends of the spectrum with monsoon regimes intermediate between them for example most of the continental rainfall 70 80 is contributed by storms having 40 dbz radar echoes reaching above 6 km strong ice scattering signature and lightning flashes this indicates that continental convection is dominated by robust mixed phase processes such as freezing of raindrops or riming of graupel supported by strong updrafts in contrast less monsoon rainfall 40 or very limited oceanic rainfall 10 involves these vigorous microphysical processes in mixed phase regions though monsoons are intermediate in convective intensity both current and previous studies show that their active periods are closer to oceanic regimes and their break periods are slightly closer to continental regimes in short this study offers novel guidance for categorization of convective properties of three regime archetypes and will be important for future regional climatological and modeling studies

the oceanic mesoscale convective system observed with airborne doppler radars on 9 february 1993 during toga coare structure evolution and budgets data collected on 9 february 1993 during the tropical ocean and global atmosphere programme coupled ocean atmosphere response experiment toga coare with the doppler radars on board the two national oceanic and atmospheric administration wp 3d and the national center for atmospheric research electra aircraft are analysed to study the structure and evolution of an equatorial oceanic mesoscale convective system mcs observations lasted more than five hours a period during which the cloud cluster characteristics changed from convective to stratiform this mesoscale system was approximately aligned along the tropospheric wind shear but it was nearly perpendicular to the low level shear series of three dimensional fields of reflectivity air velocity components retrieved pressure and temperature perturbations show similarities with previously observed convective systems over the tropical oceans in particular although the cloud top reached 18 km altitude relatively weak vertical motions and temperature perturbations resulted from a moderate convective instability in the low levels a cold front to rear flow intensified and deepened as the overall structure evolved from convective to stratiform the vertical profiles of mean horizontal divergence evolved from low level convergence in the cross line direction for the earliest analyses to mid level convergence from all directions during the later stratiform phase vertical momentum fluxes were important and led to an increase in the cross line wind shear and a decrease in the along line one analysis of radiosounding data from the nearest stations of the toga coare array shows that the period during which airborne doppler observations were conducted was characterized by relatively strong large scale ascent and apparent sources of heat moisture and momentum these diagnosed values and the mean radarderived ones agree fairly well this shows that the early convective and late stratiform phases of the mcs are equally important for the apparent sources of heat and momentum

first finding of microdiamond coesite and other uhp phases in felsic granulites in the moldanubian zone implications for deep subduction and a revised geodynamic model for variscan orogeny in the bohemian massif abstract heavy mineral fractions and polished thin sections from felsic granulites from the moldanubian zone of the bohemian massif were thoroughly studied by means of raman microspectroscopy combined with optical microscopy and scanning electron microscopy the following phases were identified among others as inclusions in robust minerals such as garnet and zircon diamond characterized by an intense narrow peak at 1332 cm 1 was found in two inclusions in zircon they have a size of 5 m coesite identified by its very characteristic peak at 520 cm 1 was found in an inclusion in garnet together with quartz coesite has been almost completely transformed into quartz only minor coesite nano domains remain kumdykolite the orthorhombic polymorph of naalsi 3 o 8 characterized by strong peaks at 220 456 and 492 cm 1 occurs either as single crystals or as a part of multiphase inclusions in garnet and in zircon along with other mineral phases such as k feldspar phengite rutile moissanite sic exhibiting the characteristic raman bands at 767 788 and 969 cm 1 occurs as inclusions in garnet diamond and coesite are considered to have formed at the peak ultrahigh pressure metamorphic uhpm conditions kumdykolite has been proposed to be a metastable phase formed during rapid cooling from high temperature moissanite points to extremely reduced conditions during subduction to great depths the finding of uhp phases in felsic granulites in the moldanubian zone is clear evidence for subduction of crustal materials to mantle depths the garnet hosting the uhp phase inclusions usually preserves prograde compositional zoning this in combination with the uhpm mineral inclusions suggests that the felsic material should have passed uhp metamorphism at a low temperature gradient isothermal decompression the commonly accepted model at temperatures of 850 950 c would have substantially modified and homogenized the garnet composition eliminating any compositional zoning therefore the uhpm felsic rocks could have experienced only a short term granulite facies metamorphism after they were exhumed to crustal levels

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

gravity wave influences on mesoscale divergence an observational case study characteristics of tropospheric low frequency gravity waves are diagnosed in radiosonde soundings from the tropicalwarm pool international cloud experiment near darwin australia the waves have typical vertical wavelengths of about 4 km horizontal wavelengths of about 600 km and intrinsic periods of about 12 hr these scales match those of the vertical horizontal and temporal variability found in area averaged horizontal wind divergence over the same domain vertical profiles of divergence show wave like structures with variability of the order of 2 10 5 s 1 in the free troposphere the results for darwin are similar to previously reported observed mesoscale patterns of divergence convergence over the tropical atlantic the findings imply that tropical divergence on spatial scales of a few hundred kilometers which is known to influence the organization of convection may be forced by gravity waves

electrically active hot towers in african easterly waves prior to tropical cyclogenesis abstract it has been hypothesized that intense convective scale hot towers play a role in tropical cyclogenesis via dynamic and thermodynamic feedbacks on the larger scale circulation in this study the authors investigate the role that widespread and or intense lightning producing convection i e electrically hot towers present in african easterly waves aews may play in tropical cyclogenesis over the east atlantic ocean the 700 hpa meridional wind from the ncep ncar reanalysis dataset was analyzed to divide the waves into northerly southerly trough and ridge phases the aews were subsequently divided into waves that developed into tropical storms i e developing and those that did not develop into tropical storms i e nondeveloping finally composites were created using various ncep variables lightning data gathered with the zeus network and worldwide lightning location network wwlln and brightness temperature data extracted from the nasa global merged infrared brightness temperatur

the interaction of clouds and dry air in the eastern tropical pacific cloud radar observations of eastern pacific intertropical convergence zone cloud vertical structure are interpreted in light of soundings 100 km scale divergence profiles calculated from precipitation radar doppler velocities and surface rain gauge data from a ship at 10 n 95 w during the 2001 east pacific investigation of climate epic experiment the transition from convective to stratiform rain is clear in all four datasets indicating a coherence from local to 100 km scale a novel finding is dry air intrusions at altitudes of 6 8 km often undercutting upper level ice clouds two distinct dry air source regions are identified one is a relatively dry area overlying the cooler waters of the costa rica oceanic thermocline dome centered approximately 400 km east northeast of the ship site the other is the even drier nearequatorial subsidence zone south of 6 7 n the former source is somewhat peculiar to this specific ship location so that the ship sample is not entirely representative of the region the 20 25 september period is studied in detail as it depicts two influences of the dry air on cloud vertical structure one is the modulation of small scale surface based convection evident as a weakening and narrowing of cloud radar reflectivity features the other springs from intense sublimation cooling as differential advection brought snowing anvil clouds over the dry layers during one half day period of strong sublimation the cooling rate is inferred to be several tens of degrees per day over a 100 hpa layer based on a heat budget estimate at 100 km scale involving the horizontal wind divergence data this is consistent with fluxing ice water contents of 0 05 0 10 g m 3 derived from the cloud radar reflectivities the temperature profile shows the dynamically expected response to this cooling a positive negative positive temperature anomaly pattern centered on the sublimating layer a buoyancy sorting diagnostic model of convection indicates that these upper troposphere temperature anomalies can cause premature detrainment of updrafts into the lower part of the cloudy layer a feedback that may actively maintain these long lasting dense anvils middle troposphere southerly dry air inflow is also evident in large scale analysis given the proximity of the dry equatorial subsidence zone to the eastern tropical pacific the differential advection of dry and cloudy air the ensuing sublimation and its dynamical aftereffects may play a role in establishing the region s climate although the extent of their significance needs to be further established

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

petrogenetic interpretation of granitoid rock series using multicationic parameters abstract granitoid rock compositions from a range of tectonic environments are plotted on a multicationic diagram devised by de la roche and his coworkers this shows that there is a systematic change through an orogenic cycle which leads progressively to the ultimate development of alkaline magmas possible source materials and mechanisms of magma generation are considered from analysis of mineral compositional vectors these suggest that most granitoid series result from a two stage process first fractional crystallisation of clinopyroxene olivine and calcic plagioclase from a basic source with tholeiitic affinities produces a magma of intermediate composition this magma then undergoes periodic mixing with a felsic magma followed by in situ fractionation to generate individual intrusions within granitoid series

baroclinicity influences on storm divergence and stratiform rain subtropical upper level disturbances abstract divergence structures associated with the spectrum of precipitating systems in the subtropics and midlatitudes are not well documented a mesoscale model is used to quantify the relative importance different baroclinic environments have on divergence profiles for storms primarily caused by upper level disturbances in southeastern texas a subtropical region the divergence profiles simulated for a subset of the modeled storms are consistent with those calculated from an s band doppler radar realistic convective and stratiform divergence signals are also generated when applying a two dimensional convective stratiform separation algorithm to reflectivities derived from the mesoscale model although the model appears to underestimate stratiform rain area divergence profiles from the modeled precipitating systems vary in magnitude and structure across the wide range of baroclinicities common in southeastern texas barotropic storms more characteristic of the tropics generate the most elevated diver

paleozoic evolution of continental crust in the beaujolais lyonnais area northeastern part of the massif central france in the beaujolais lyonnais area of the northeastern massif central accretion of continental and possibly oceanic crustal fragments occurred between cambrian and early carboniferous time three distinct lithotectonic units terranes have been recognized the southern lyonnais unit consists of medium to high grade metamorphics and includes eclogites it formed in the early paleozoic the brevenne unit to the north contains low to medium grade metamorphic mafic and felsic volcanics and subordinate sedimentary rocks which possibly originated during the early paleozoic until devonian time in a sialic back arc environment or along an active continental margin the beaujolais unit is represented by volcanics on the south and predominantly shallow marine clastics and carbonates on the north it developed in a late devonian or early carboniferous ensialic marginal basin the peak of metamorphism in the lyonnais unit hp ht was reached in silurian time subsequent nw se to e w oriented convergence produced mylonitic foliation structural imbrication of the lyonnais basement rocks with the brevenne unit and se vergent folds accompanied by low to medium grade metamorphism late visean to namurian n s to nw se directed n vergent thrusting produced tectonic imbrication of the metamorphic northern brevenne unit with the nonmetamorphic beaujolais unit in the southern brevenne unit and in the lyonnais unit updoming along right lateral high angle normal faults was followed by emplacement of voluminous granitic plutons of crustal origin late carboniferous to early permian crustal thinning in the beaujolais lyonnais area was associated with n s trending left lateral strike slip faults and e w to ne sw trending right lateral strike slip faults basins that developed along these faults contain continental red beds

balanced contributions to the intensification of hurricane opal as diagnosed from a gfdl model forecast abstract stationary and propagating asymmetric features of atmospheric or oceanic origin near a hurricane are known to have an impact on its evolution although theoretical and observational studies have investigated the influence of such features on hurricane intensification the degree to which either environmental or near core region asymmetries of heating friction or potential vorticity pv in contrast to symmetric processes weaken or intensify a hurricane has not been established the present study uses the symmetric balanced model formulation of eliassen and its extension to asymmetric balance ab to evaluate the impact of heating and friction as well as eddy fluxes on the intensification of hurricane opal of 1995 in a geophysical fluid dynamics laboratory gfdl model forecast the diagnostics are made in cylindrical coordinates with the symmetric vortex as the basic state and asymmetries as the environment the application of ab which explicitly includes the effects of asymmetric heating

coincidence of gabbro and granulite formation and their implication for variscan ht metamorphism in the moldanubian zone bohemian massif example from the kutna hora complex abstract leucocratic metagabbro and amphibolite from a mafic ultramafic body within migmatite and granulite in the kutna hora complex were investigated the mafic ultramafic rocks show amphibolite facies metamorphism but in the central part of the body some metagabbro preserves cumulus and intercumulus plagioclase clinopyroxene and spinel spinel forms inclusions in both clinopyroxene and plagioclase and shows various degree of embayment structure that was probably a result of reaction with melt during magmatic crystallization in the metagabbro garnet forms coronae around clinopyroxene at the contacts with plagioclase amphibolite contains garnet with prograde zoning and plagioclase phase relations of igneous and metamorphic minerals indicate that magmatic crystallization and subsequent metamorphism occurred as a result of isobaric cooling at a depth of 30 35 km u pb dating on zircon from leucogabbro yielded a variscan age 337 7 2 ma that is similar or close to the age of granulite facies metamorphism ca 340 ma in the moldanubian zone based on the calculated pt conditions and age data both the mafic ultramafic body and surrounding granulite shared the same exhumation path from their middle lower crustal position at the end of variscan orogeny the coincidence of mafic ultramafic intrusives and granulite amphibolite facies metamorphism is explained by lithospheric upwelling beneath the moldanubian zone that occurred due to slab break off during the final stages of subduction of the moldanubian plate beneath the tepla barrandian block the model also addresses questions about the preservation of minerals and or their compositions from the early metamorphic history of the rocks subjected to ultradeep subduction and subsequent granulite facies metamorphism

radar observations of the kinematic microphysical and precipitation characteristics of two mcss in trmm lba 1 dual doppler and polarimetric radar observations are used to analyze two mesoscale convective systems mcss that occurred during the tropical rainfall measuring mission large scale biosphere atmosphere field campaign the mcss formed in different meteorological regimes based on profiles of atmospheric wind and thermodynamic data the first mcs event 26 january 1999 was a squall line that formed in low level easterly flow and had an intense leading line of convection in contrast the 25 february 1999 mcs formed in low level westerly flow and was best characterized by stratiform precipitation with embedded convective elements the radar analyses suggest that the mcss were distinct in terms of overall vertical structure characteristics in particular polarimetric radar cross sections indicated the presence of an active mixed phase zone in the easterly mcs that was largely absent in the westerly case the easterly mcs had considerably more precipitation ice in the middle to upper troposphere compared to the westerly mcs composite analyses showed that the easterly mcs had higher peak reflectivities and a smaller reflectivity gradient above the 08c level in convective regions of the storm compared to the westerly mcs event moreover mean profiles of both vertical air motion and vertical mass transport in the convective portion of the easterly mcs were larger over a factor of 2 at some heights below the 08 c level than those in the westerly event these observations suggest that the easterly and westerly wind regimes in the southwest amazon region produce convection with different vertical structure characteristics similar to regimes elsewhere in the global tropics e g maritime continent index terms 3314 meteorology and atmospheric dynamics convective processes 3329 meteorology and atmospheric dynamics mesoscale meteorology 3354 meteorology and atmospheric dynamics precipitation 1854 3374 meteorology and atmospheric dynamics tropical meteorology keywords microphysics tropical precipitation polarimetric radar mesoscale convective system

modeling tropical precipitation in a single column abstract a modified formulation of the traditional single column model for representing a limited area near the equator is proposed this formulation can also be considered a two column model in the limit as the area represented by one of the columns becomes very large compared to the other only a single column is explicitly modeled but its free tropospheric temperature rather than its mean vertical velocity is prescribed this allows the precipitation and vertical velocity to be true prognostic variables as in prior analytical theories of tropical precipitation two models developed by other authors are modified according to the proposed formulation the first is the intermediate atmospheric model of j d neelin and n zeng but with the horizontal connections between columns broken rendering it a set of disconnected column models the second is the column model of n o renno k a emanuel and p h stone in the first model the set of disconnected column models is run with a fixed temperature

boundaries of mantle lithosphere domains in the bohemian massif as extinct exhumation channels for high pressure rocks abstract five domains microplates have been recognized by seismic anisotropy in the mantle lithosphere of the bohemian massif the mantle domains correspond to major crustal units and each of the domains bears a consistent fossil olivine fabric formed before their variscan assembly the present day mantle fabric indicates that this process consisted of at least three oceanic subductions each followed by an underthrusting of the continental lithosphere the seismic anisotropy does not detect remnants of the oceanic subductions but it can trace boundaries of the preserved continental domains subsequently underthrust along the paths of previous oceanic subductions the most robust continent continent collision was followed by westward underthrusting of the brunovistulian mantle lithosphere still detectable by seismic anisotropy more than 100 km beneath the moldanubian mantle lithosphere major occurrences of the high pressure ultra high pressure hp uhp rocks follow the ene and nne oriented sutures and boundaries of the mantle lithosphere domains mapped from three dimensional modeling of body wave anisotropy the hp uhp rocks are products of oceanic subductions and the following underthrusting of the continental crust and mantle lithosphere exhumed along the mantle boundaries the close relation of the mantle sutures and occurrences of the hp uhp rocks near the paleosubductions testifies for models interpreting the granulite garnet peridotite association by oceanic continental subduction underthrusting followed by the exhumation of deep seated rocks our findings support the bivergent subduction model of tectonic development of the central part of the bohemian massif the inferences from seismic anisotropy image the bohemian massif as a mosaic of microplates with a rigid mantle lithosphere preserving a fossil olivine fabric the collisional mantle boundaries blurred by tectonometamorphic processes in easily deformed overlying crust served as major exhumation channels of the hp uhp rocks

on the annual variation of tropospheric zonal winds observed above christmas island in the central equatorial pacific observations of tropospheric winds have been made nearly continuously since early 1986 in the altitude range 2 18 km using a 50 mhz vhf wind profiler at christmas island 2 n 157 w tropospheric zonal winds observed at christmas island show a pronounced annual variation in the middle to upper troposphere with westerly winds typically observed during northern winter the annual variation is strongest during la nina and weakest during el nino the amplitude of the cycle has a broad peak in the upper troposphere empirical orthogonal function eof analysis of the vertical structure of the annual variation shows that the principal mode explains nearly 90 of the variance in the 90 to 365 day frequency band we attribute the annual variation in zonal winds to the annual variation in deep tropical heating associated with deep convection the annual variation in tropical convection gives rise to annual variations in the surface pressure and pressure difference between darwin and tahiti the pressure difference is greatest during northern hemisphere winter months other measures of the annual variation in tropical convection are provided by the tropical tropopause height and by highly reflective clouds hrc the tropical tropopause is highest during the northern hemisphere winter months when convection is most active over the maritime continent western pacific warm pool region and lowest in northern summer when convection is most active over the land masses of the northern hemisphere the hrc show an annual migration in the centers of active convection the annual latitudinal migration of the active centers of convection over the western pacific with respect to the equatorial waveguide appears to be an important factor in determining the annual variation evident in the remote response of the zonal winds observed over christmas island

on the consistency between dynamical and thermodynamic equations with prescribed vertical motion in an analytical tropical cyclone model in our earlier paper we presented an analytical model for intensifying tropical cyclones tcs in which the effects of all nonlinear terms in the horizontal momentum equations are retained this analytical model was obtained by prescribing the time evolution of the vertical motion in this paper we demonstrate that with the prescribed vertical motion the system of governing equations for geophysical flows can be separated into two subsystems one consisting of the horizontal momentum and continuity equations and the other including the vertical momentum and thermodynamical equations results show that the analytical solutions for the horizontal winds obtained from the first subsystem are consistent with the mass field in the second subsystem such as the thermal wind relationship in tcs furthermore we show that use of any functional form for the mean vertical motion will not affect our previous major conclusions about the different growth rates either between the secondary and primary circulations or between the inner and outer regions in tcs copyright 2010 royal meteorological society

fluoride contamination of groundwater in parts of eastern india and a preliminary experimental study of fluoride adsorption by natural haematite iron ore and synthetic magnetite incidence of high fluoride f in groundwater 1 5 mg l in two tribal belts of eastern india one around chukru in the palamau district of jharkhand and the other around karlakot in the nuapada district of odisha has been studied the maximum concentration of f in groundwater from dug wells and tube wells is 10 30 mg l in chukru and 4 62 mg l in karlakot the groundwaters are mildly alkaline with ph ranges of 7 52 8 22 and 7 33 8 20 in chukru and karlakot respectively the f concentration is positively correlated with ph electrical conductivity and so4 2 in both areas the high f in groundwater resulted mainly from dissolution of biotite and fluorapatite in quartzofeldspathic gneiss the ionic dominance pattern in meq l is mostly in the order ca2 na mg2 k among cations and hco3 so4 2 f among anions in the karlakot groundwater preliminary adsorption experiments were conducted on natural haematite iron ore and synthetic magnetite to evaluate their potential for f removal from water effects of different parameters such as contact time ph adsorbent dose and initial f concentration on the adsorption capacity of these materials were investigated strong dependence of f removal on ph was observed for both the adsorbents with natural haematite iron ore the maximum f removal of 66 occurred at an initial ph of 3 2 for a solution with f concentration of 3 mg l adsorbent dose of 7 g l and overnight contact time the haematite iron ore was observed to increase the ph of the f solution adsorption equilibrium was not achieved with this adsorbent even after a contact time of 45 2 h in the case of synthetic magnetite 84 f removal was achieved after 2 min of contact time for a solution with f concentration of 6 mg l adsorbent dose of 10 g l and initial ph of 7 the results indicate high potential of both natural haematite iron ore and synthetic magnetite as adsorbents of f in water

potential vorticity generation by west african squall lines abstractthe west african summer monsoon features multiple complex interactions between african easterly waves aews moist convection variable land surface properties dust aerosols and the diu

multiscale convective wave disturbances in the tropics insights from a two dimensional cloud resolving model abstract multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating two dimensional cloud model forced by uniform cooling to articulate the dynamics of these waves model outputs are objectively analyzed in a discrete truncated space consisting of three cloud types shallow convective deep convective and stratiform and three dynamical vertical wavelength bands model experiments confirm that diabatic processes in deep convective and stratiform regions are essential to the formation of multiscale convective wave patterns specifically upper level heating together with low level cooling serves to preferentially excite discrete horizontally propagating wave packets with roughly a full wavelength structure in troposphere and dry phase speeds cn in the range 16 18 m s 1 these wave packets enhance the triggering of new deep convective cloud systems via low level destabilization the new convection in turn caus

assessing the applicability of the tropical convective stratiform paradigm in the extratropics using radar divergence profiles abstractlong term radar observations from a subtropical location in southeastern texas are used to examine the impact of storm systems with tropical or extratropical characteristics on the large scale circulation climatological vertical profiles of the horizontal wind divergence are analyzed for four distinct storm classifications cold frontal cf warm frontal wf deep convective upper level disturbance dc uld and nondeep convective upper level disturbances nc uld dc uld systems are characterized by weakly baroclinic or equivalent barotropic environments that are more tropical in nature while the remaining classifications are representative of common midlatitude systems with varying degrees of baroclinicity dc uld systems are shown to have the highest levels of nondivergence lnd and implied diabatic heating maxima near 6 km whereas the remaining baroclinic storm classifications have lnd altitudes that are about 0 5 1 km lower analyses of climatological mean divergence profiles are also s

a low level circulation in the tropics abstract deep convective tropical systems are strongly convergent in the midtroposphere horizontal wind measurements from a variety of rawinsonde arrays in the equatorial pacific and caribbean are used to calculate the mean dynamical divergence profiles of large scale arrays 1000 km in diameter in actively convecting regions somewhat surprisingly the magnitude of the midtropospheric divergence calculated from these arrays is usually small in principle the midlevel convergence of deep convective systems could be balanced on larger scales either by a vertical variation in the radiative mass flux of the background clear sky atmosphere or by a divergence from shallow cumuli the vertical variation of the clear sky mass flux in the midtroposphere is small however so that the offsetting divergence must be supplied by shallow cumuli on spatial scales of 1000 km the midlevel convergent inflow toward deep convection appears to be internally compensated or screened by a divergent outflow from surr

thermodynamic aspects of tropical cyclone formation abstractthe thermodynamic aspects of tropical cyclone tc formation near the center of the wave pouch a region of approximately closed lagrangian circulation within the wave critical layer are examined through diagnoses of a high resolution numerical simulation and dropsonde data from a recent field campaign it is found that the meso area near the pouch center is characterized by high saturation fraction small difference in equivalent potential temperature e between the surface and the middle troposphere and a short incubation time scale updrafts tend to be more vigorous in this region presumably because of reduced dry air entrainment while downdrafts are not suppressed the thermodynamic conditions near the pouch center are thus critically important for tc formation the balanced responses to convective and stratiform heating at the pregenesis stage are examined using the sawyer eliassen equation deep convection is concentrated near the pouch center the strong radial and vertical gradients o

a vortical hot tower route to tropical cyclogenesis abstract a nonhydrostatic cloud model is used to examine the thermomechanics of tropical cyclogenesis under realistic meteorological conditions observations motivate the focus on the problem of how a midtropospheric cyclonic vortex a frequent by product of mesoscale convective systems during summertime conditions over tropical oceans may be transformed into a surface concentrated warm core tropical depression as a first step the vortex transformation is studied in the absence of vertical wind shear or zonal flow within the cyclonic vorticity rich environment of the mesoscale convective vortex mcv embryo the simulations demonstrate that small scale cumulonimbus towers possessing intense cyclonic vorticity in their cores vortical hot towers vhts emerge as the preferred coherent structures the vhts acquire their vertical vorticity through a combination of tilting of mcv horizontal vorticity and stretching of mcv and vht generated vertical vorticity horizontally localized and exhibiting conve

oblique crustal detachment in the variscan schwarzwald southwestern germany the schwarzwald is part of the central polymetamorphic crystalline belt of the variscan orogen moldanubian belt from north to south it consists of four terranes the metasedimentary zone of baden baden the polymetamorphic central schwarzwald gneiss complex the sedimentary metamorphic zone of badenweiler lenzkirch and the hotzenwald complex the largest of these terranes is the central schwarzwald gneiss complex csgc whose rocks record a history of protracted regional metamorphism and anatectic melt generation during variscan convergence between 350 and 325 ma the csgc became detached from a high temperature lower crustal substratum and was emplaced southeastward over paleozoic clastics volcanic rocks and crystalline slivers of the zone of badenweiler lenzkirch and the hotzenwald complex kinematic indicators suggest that these early convergent movements on retrograde shear zones and the concomitant crustal thickening were superseded by movements on divergent shear zones the ascent of voluminous granitic plutons from a mid crustal zone of melt generation into the upper crust was probably triggered by a change in the crustal kinematics from overall convergence to overall divergence at about 325 ma in detail this process was probably diachronous detachment of upper crust and large scale melt generation in the middle crust of the schwarzwald was probably facilitated by the tectonic stacking of water rich pelitic clastics and gneiss slivers with relatively even proportions of crystalline and pelitic materials

scale interactions involved in the initiation structure and evolution of the 15 december 1992 mcs observed during toga coare part i synoptic scale processes this paper the first of a series examines the synoptic scale mechanisms involved in the initiation structure and evolution of a mesoscale convective system observed during toga coare this study relies upon the use of the japanese geosynchronous meteorological satellite 4 imagery and ecmwf model outputs from which diagnostic parameters are derived and interpreted this mesoscale convective system consists initially of two groups of convective entities that progressively move toward each other and merge it is shown that the synoptic scale flow creates a favorable environment for the formation of this large convective system through the production of convective available potential energy cape by horizontal advection and the enhancement of low level convergence in the region where the convective system formed moreover the general evolution of the system is found to be governed by the synoptic scale circulation and more precisely by the temporal evolution of cape and low level convergence the mechanisms leading to the initiation and general evolution of the system are examined the easterly equatorial jet at 500 hpa triggered positive potential vorticity areas that propagated westward and generated an anticyclonic circulation this anticyclonic circulation was enhanced during the development phase of the convective system through vortex stretching and tilting which accelerated the low level westerlies corresponding to the southern branch of this circulation and enhanced the low level convergence associated with the studied convective system in a companion paper the mesoscale and convective scale processes involved in the internal organization of this mesoscale convective system are examined using the airborne doppler radar dataset collected within the system from 1700 to 2100 utc the downscale interactions i e from synoptic scale to mesoscale and convective scale are scrutinized using both the synoptic scale context described in this paper and the mesoscale and convective scale characteristics derived from the airborne radar observations

chronological constraints on the pre orogenic history burial and exhumation of deep seated rocks along the eastern margin of the variscan orogen bohemian massif czech republic key lithological units of the high grade eastern margin of the bohemian massif were dated using the u pb and pb pb methods on zircons in order to establish a chronological framework for the geodynamic evolution of the variscan orogenic root the protolith ages for metagranitoids orthogneisses and granulites of thickened lower and middle crust reveal the existence of magmatic activity that occurred over a 100 million year time interval from cambro ordovician to early devonian times probably related to discontinuous intracontinental rifting of neoproterozoic crust our geochronological data suggest that the eastern part of the orogenic root represents thermally softened and rifted neoproterozoic crust preserved farther to the east as the brunia microcontinent zircon ages for felsic granulites high grade gneisses of the lower crust and of a syn convergence granodioritic intrusion in the upper crust indicate that thickening and exhumation of the crust occurred during a narrow time interval between 370 and 340 ma exhumation of the lower crust to mid crustal levels was a localized process that occurred at 340 ma and was associated with crustal scale folding in the internal part of the root as well as orogenic channel flow along the eastern collisional margin both types of exhumation mechanisms were driven by deep level wedging indentation of the easterly brunia continent followed by deposition of heavy minerals and pebbles derived from high pressure rocks in the adjacent foreland basin final orogenic development was characterized by ne sw dextral transpressive shearing parallel to the brunia margin as well as dextral trans tension associated with activity along the elbe lithospheric fault these processes affected the marginal parts of the orogenic root and were accompanied by 330 to 325 ma old syntectonic granitoid intrusions along reactivated lithotectonic boundaries rotation of the assembled orogenic belt accompanied by lithospheric faulting driven by westerly subduction roll back may be the most plausible model to explain late deformation of the orogenic root

an investigation of composite dropsonde profiles for developing and nondeveloping tropical waves during the 2010 predict field campaign abstractcomposite dropsonde profiles are analyzed for developing and nondeveloping tropical waves in an attempt to improve the understanding of tropical cyclogenesis these tropical waves were sampled by 25 reconnaissance missions during the 2010 pre depression investigation of cloud systems in the tropics predict field campaign comparisons are made between mean profiles of temperature mixing ratio relative humidity radial and tangential winds relative vorticity and virtual convective available potential energy cape for genesis and nongenesis cases genesis soundings are further analyzed in temporal progression to investigate whether significant changes in the thermodynamic or wind fields occur during the transition from tropical wave to tropical cyclone significant results include the development of positive temperature anomalies from 500 to 200 hpa 2 days prior to genesis in developing waves this is not observed in the nongenesis mean progressive mesoscale moistening of the column is observe

tropical inversions near the 0 c level abstract soundings taken from the tropical western pacific warm pool region during toga coare reveal the common occurrence of temperature and moisture perturbations near the 0 c level the perturbations frequently are characterized by shallow layers of increased stability or occasionally temperature inversions and reversals or inflections in the vertical profile of specific humidity similar temperature and moisture inversions have been observed elsewhere in the tropics and midlatitudes but have not received much attention isothermal layers are known to exist just below the melting level in stratiform rain regions however not all stable layers observed over the warm pool are confined to precipitation systems the perturbation in the specific humidity profile accounts for the often observed double peak structure in the apparent moisture sink q2 in tie tropics stratification of the data based on relative humidity criteria indicates that the stable layers near the 0 c level generally fall into two main

mesoscale observations of the genesis of hurricane dolly 1996 abstract recent numerical studies of tropical cyclone genesis suggest a new paradigm for how the surface vortex is established based on a highly nonaxisymmetric mechanism involving the interaction of low level cyclonic circulations generated by deep cumulonimbus convection a reexamination of mesoscale observations during the genesis of hurricane guillermo 1991 confirms the presence of multiple cyclonic circulations more recently airborne doppler radar wind observations during the genesis of atlantic hurricane dolly 1996 also reveal multiple lower to middle tropospheric mesoscale cyclonic circulations during sequential 15 20 min compositing periods a particularly well organized but initially weak mean tangential wind of 7 m s 1 low level cyclonic vortex embedded within the pre dolly tropical disturbance is observed coincident with deep vertically penetrating cumulonimbus convection the earliest observations of this vortex show the peak circulation near 2 km height with a mean diameter of 30 4

the horizontal spectrum of vertical velocities near the tropopause from global to gravity wave scales abstractvertical motions are fundamental for atmospheric dynamics compared to horizontal motions the horizontal spectrum of vertical velocity w is less well known here w spectra are related to

a petrogenetic grid for pelitic schists in the system sio 2 al 2 o 3 feo mgo k 2 o h 2 o a quantitative petrogenetic grid for pelitic schists in the system kfmash that includes the phases garnet chlorite biotite chloritoid cordierite staurolite talc kyanite andalusite sillimanite and pyrophyllite with quartz h2o and muscovite or k feldspar in excess is presented the grid is based on thermodynamic data of berman et al 1985 and berman 1988 for endmember kfash and kmash equilibria and natural fe mg partitioning for the kfmash system calculation of p t slopes and the change in fe fe mg along reactions in the kfmash system were made using the gibbs method in addition the effect on the grid of mno and cao is evaluated quantitatively the resulting grid is consistent with typical buchan and barrovian parageneses at medium to high grades at low grades the grid predicts an extensive stability field for the paragenesis chloritoid biotite which arises because of the unusual facing of the reaction chloritoid biotite quartz h2o garnet chlorite muscovite which proceeds to the right with increasing t in the kfmash system however the reaction proceeds to the left with increasing t in the mnkfash system so the assemblage chloritoid biotite is restricted to bulk compositions with high fe fe mg mn typical metapelites will therefore contain garnet chlorite at low grades rather than chloritoid biotite

beginning of melting in the granite system qz or ab an h2o the beginning of melting in the system qz or ab an h2 o was experimentally reversed in the pressure range p text h text 2 text o 2 15 kbar using starting materials made up of mixtures of quartz and synthetic feldspars with increasing pressure the melting temperature decreases from 690 c at 2 kbar to 630 c at 17 kbar in the an free alkalifeldspar granite system qz or ab h2o in the granite system qz or ab an h2o the increase of the solidus temperature with increasing an content is only very small in comparison to the alkalifeldspar granite system the solidus temperature increases by 3 c 7 c if albite is replaced by plagioclase an 20 an 40 the difference between the solidus temperatures of the alkalifeldspar granite system and of quartz anorthite sanidine assemblages system qz or an h2o is approximately 50 c

kinematics of compressional and extensional ductile shearing deformation in a metamorphic core complex of the northeastern basin and range abstract analysis of shear criteria enables the kinematics of two main ductile shearing events d 1 and d 2 to be established in the raft river grouse creek and albion metamorphic core complex the first event d 1 is a nne thrusting and corresponds to mesozoic shortening a well developed non coaxial ductile deformation d 2 of cenozoic age is marked by the occurrence of opposing eastward in raft river and westward shear criteria in albion grouse creek these characterize an arch structure where the shear strain increases outwards in the axial zone of the complex d 2 seems coaxial cenozoic extension is considered to be related to gravitational instability induced by mesozoic overthickening of the crust involving uplift erosion and abnormal heating brittle extension occurs in the upper part of the uplifted domain it is transformed laterally above undeformed basement towards stretched domains of the middle and lower crust through the ductile shear zones localized at the precambrian paleozoic interface this extension of the middle and lower crust occurred in the vicinity of the root zones of the former mesozoic thrusts which may thus have been reactivated as ductile normal faults during cenozoic extension

re os geochemistry and geochronology of the ransko gabbro peridotite massif bohemian massif the ransko gabbro peridotite massif in eastern bohemia is a strongly differentiated intrusive complex which hosts low grade ni cu ores mainly developed close to the contact of olivine rich rocks with gabbros in troctolites and to a much lesser extent in both pyroxene and olivine gabbros and plagioclase rich peridotites gabbro troctolite peridotite and ni cu ores from the jezirka ni cu pge deposit considered to be a typical example of the liquid segregation style of mineralization were analyzed for re os concentrations and isotopic ratios seven barren and mineralized samples from the jezirka deposit yielded a re os regression of 341 5 7 9 ma mswd 69 strongly mineralized peridotite with mantle like initial 187os 188os ratio of 0 125 suggests that os as well as other pge present in the ni cu mineralization are predominantly of mantle origin on the other hand barren and low mineralized samples have radiogenic initial 187os 188os ratios of 0 14 0 16 suggesting some import of re and or radiogenic 187os most likely through contamination by continental crust during magma emplacement the re os age of the ransko massif is significantly younger than the previously suggested lower cambrian age but it is similar to and or younger than the age of metamorphism of the adjacent kutna hora crystalline complex and the moldanubian unit therefore it is likely that the emplacement of the ransko massif and its ni cu mineralization was closely connected with the late stage evolution of the kutna hora crystalline complex

strain coupling between upper mantle and lower crust natural example from the běstvina granulite body bohemian massif strain patterns within mantle rocks and surrounding coarse grained felsic granulites from the kutna hora crystalline complex in the variscan bohemian massif have been studied in order to assess their strain coupling the studied rock association occurs within low strain domains surrounded by fine grained granulite and migmatite the doubrava peridotite contains closely spaced and steeply dipping layers of garnet clinopyroxenite which are parallel to the ne sw striking high temperature foliation in nearby granulites while the uhrov peridotite lacks such layering the spacice eclogite is not associated with peridotite and shows upright folds of alternating coarse and fine grained varieties bearing ne sw striking axial planes electron back scattered diffraction measurements revealed full strain coupling between clinopyroxenites and coarse grained granulites in the s1 fabric that is superposed on the s0 fabric preserved in peridotites the b type olivine lattice preferred orientation lpo characterizes the s0 fabric in peridotites and its reworking is strongly controlled by the presence of macroscopic clinopyroxenite layering the s1 in clinopyroxenites and coarse grained granulites is associated with the ls type clinopyroxene lpo and prism slip in quartz respectively while the s1 fabric in these rock types is accompanied invariably by a sub vertical stretching lineation the s1 fabric developed in reworked uhrov peridotite is associated with strongly planar axial 010 type of olivine lpo the peridotites with the s0 fabric are interpreted to be relicts of a fore arc mantle wedge hydrated to a various extent above the saxothuringian subduction zone the prograde metamorphism recorded in peridotites and eclogites occurred presumably during mantle wedge flow and was reaching uhp conditions strain coupling in the s1 fabric between clinopyroxenites and granulites at doubrava and upright folding of eclogites at spacice document a link between tectonic and magmatic processes during orogenic thickening coeval with intrusions of the arc related calcalkaline suites of the central bohemian plutonic complex c 360 345 ma juxtaposition of peridotites and granulites could be explained by a rheological heterogeneity connected to the development of clinopyroxenite layering in the upper mantle and a previously published model of a lithospheric scale transpressional arc system it invokes vertical shearing along ne sw trending sub vertical foliations in the upper mantle that could have led to an emplacement of mantle bodies into the granulitized orogenic root in the sub arc region clearly such a transpressional arc system could represent an important pathway for an emplacement of deep seated rocks in the orogenic lower crust

polykinematic foreland basins initiated during orthogonal convergence and terminated by orogen oblique strike slip faulting an example from the northeastern variscan belt abstract an extensive early carboniferous foreland basin the moravosilesian culm basin mscb delineates the northeastern margin of the bohemian massif variscan orogenic belt the basin overlays a complex suture between the outer brunovistulia microplate forming a promontory previously accreted to laurussia and inner gondwana derived units that form the remainder of the bohemian massif our structural paleomagnetic and magnetic anisotropy data from the eastern portion of the mscb indicate that its depositional architecture internal fabric and deformation by folding and faulting record a major switch from orthogonal convergence to orogen oblique strike slip shearing first the brunovistulia microcontinent was subducted frontally towards w during 346 335 ma followed by a shift of the subduction vector towards ssw at around 335 330 ma from 330 ma onwards the underthrusting had ceased and the wnw ese dextral elbe shear zone related to the westward movement of gondwana with respect to laurussia controlled deformation of this region displacement of the northerly eastern sudetes block towards ese produced regional wnw ese pure shear shortening against the brunovistulia indentor and resulted in an overall doubly vergent structure of the mscb simultaneously the southerly moldanubian unit was translated towards wnw away from the brunovistulian microplate and likely contributed to an extensional regime related to orogenic collapse progressing outward from the internal domains of the bohemian massif on a larger scale we suggest that the mscb is an illustrative example of a polykinematic foreland basin where deposition syn to post sedimentary deformation and thus geodynamic processes changed significantly during basin evolution starting off with microplate impingement into a continental margin reentrant and terminated by strike slip shearing our data also do not support previous models for the tectonic development of the northeastern termination of the variscan belt which suggested either a large magnitude vertical axis oroclinal rotation of the foreland or its translation along an orogen perpendicular strike slip fault

superposition of variscan ductile shear deformation on pre variscan mantled gneiss structure catherine dome erzgebirge bohemian massif three tectonometamorphic events have been recognized in the crystalline rocks of the catherine mantled gneiss dome cd in the central erzgebirge the first tectonometamorphic event is characterized by the acquisition of a s1 s2 metamorphic foliation development of f2 isoclinal partly syn schistose folding and intrusion of early synkinematic granites p t conditions correspond to higher amphibolite facies metamorphism and culminate in anatexis a diapiric intrusion of cambro ordovician muscovite biotite porphyritic granite has verticalized the s2 foliation and is responsible for the genesis of the classical mantled gneiss dome oblate strain and orthorhombic diffuse c axis patterns are typical of the marginal parts of the dome

measuring area averaged vertical motions with dropsondes abstractmeasurements of vertical profiles of areal mean mass divergence vorticity and vertical velocity based on dropsondes distributed over an area of 25 000 km2 are presented the dropsondes

mesoscale convective systems 1 mesoscale convective systems mcss have regions of both convective and stratiform precipitation and they develop mesoscale circulations as they mature the upward motion takes the form of a deep layer ascent drawn into the mcs in response to the latent heating and cooling in the convective region the ascending layer overturns as it rises but overall retains a coherent layer structure a middle level layer of inflow enters the stratiform region of the mcs from a direction determined by the large scale flow and descends in response to diabatic cooling at middle to low levels a middle level mesoscale convective vortex mcv develops in the stratiform region prolongs the mcs and may contribute to tropical cyclone development the propagation of an mcs may have a discrete component but may further be influenced by waves and disturbances generated both in response to the mcs and external to the mcs waves of a larger scale may affect the propagation velocity by phase locking with the mcs in a cooperative mode the horizontal scale of an mcs may be limited either by a balance between the formation rate of convective precipitation and dissipation of stratiform precipitation or by the rossby radius of the mcv the vertical redistribution of momentum by an mcs depends on the size of the stratiform region while the net vertical profile of heating of the large scale environment depends on the amount of stratiform rain regional variability of the stratiform rain from mcss affects the large scale circulation s response to mcs heating

terrane character of the north east margin of the moldanubian zone the kutna hora crystalline complex bohemian massif three major allochthonous units have been distinguished on the north eastern border of the moldanubian zone which differ each from other in lithology and structural and metamorphic evolution their present day position displays significant metamorphic and structural inversion resulting from progressive nappe stacking during the variscan orogeny the uppermost gfohl unit consists of anatectic rocks containing high temperature high pressure relics i e granulites eclogites and garnet peridotites the rocks of the gfohl unit were strongly mylonized during uplift and later also extensively migmatized in the kyanite stability field the koui im nappe is built up by a sequence of fine grained leucocratic migmatites with preserved relics of a pre variscan deformation event this event was terminated by the intrusion of coarse grained porphyritic granites converted into augen orthogneisses by the variscan orogeny the lowermost micaschist zone was formed from a sequence of metapelites intercalated with diopsidic amphibolites

genesis of high f groundwaters southern india abstract high f groundwaters are common in the dry parts of the indian peninsula constituting a serious health problem the f originates mainly from hydroxypositions in biotite and hornblende and is concentrated through evapotranspiration in soil and groundwater exhibiting residual alkalinity such waters are common in areas with generally alkaline soils along the flow paths of the water from hilltops to valley bottoms calcite dolomite and fluorite seem to precipitate in that order a practical solution to the health problem may be to locate drinking water wells in upslope positions

differences between faster versus slower components of convectively coupled equatorial waves abstractthis paper describes an analysis of multiyear satellite datasets that subdivide two halves faster and slower of the space time spectral signal peaks corresponding to convectively coupled equatorial waves such as kelvin and inertia gravity waves n 0 eastward inertia gravity wave eign0 wave and n 1 and n 2 westward inertia gravity waves wign1 and wign2 waves respectively the faster slower component of an equatorial wave is defined as that which has a spectral signal peak in the regions with deeper shallower equivalent depths the data obtained from the tropical rainfall measuring mission trmm precipitation radar trmm pr are composited around space time filtered equatorial belt data from the trmm 3b42 rainfall product to separately estimate the convective and stratiform rainfall modulations results indicate that the faster components of wign1 and wign2 waves modulate convective rain relatively more and stratiform rain relatively less than their slower counterparts for kelv

diabatic divergence profiles in western pacific mesoscale convective systems abstract heating in the atmosphere can be expressed as diabatic divergence d which is nearly equal to the actual horizontal divergence in tropical convection high quality profile measurements from airborne doppler radar purls in ten mesoscale convective systems mcs observed during toga coare are examined and the mean profile is compared with rawinsonde array measurements young convective features have strong near surface convergence while older cells with better developed downdrafts and stratiform precipitation areas have their peak convergence aloft in the mean then surface flow is only weakly convergent or oven divergent so that the main convergence into mcss is deep and peaked aloft with a sharp melting convergence at 0 c divergence prevails above 10 km altitude but was undersampled by the radar unusual but well sampled observations in the purl dataset include a persistent widespread profile feature in one well sampled mcs a cyclone rainband oscillatory reverberations c

controls on the genesis of some high fluoride groundwaters in india india has an increasing incidence of fluorosis dental and skeletal with some 62 million people at risk high fluoride groundwaters are present especially in the hard rock areas south of the ganges valley and in the arid north western part of the country the phenomenon is related to groundwater with residual alkalinity ca2 hco3 fluoride concentrations are governed by adsorption equilibria and by fluorite solubility evapotranspiration leads to a precipitation of calcite a lowering of ca activity and increase in na ca ratios and this allows an increase in f levels in southern india mg seems to be controlled by dolomite while sepiolite and palygorskite are mg sinks in rajasthan but may then release f under alkaline conditions the latter two minerals are probably also important sources and sinks for f in the hydroxy positions the increase in the extent of sodic soils as a result of irrigation is a contributing factor to the increasing incidence of fluorosis remedial measures including addition of gypsum and rainwater harvesting are needed even in areas where the sodicity does not cause structural problems in the soil

vertical temperature structure associated with evaporation of stratiform precipitation in idealized wrf simulations abstracta recent study based on observations has shown that after precipitation over tropical oceans rather shallow temperature structures occur in the lower troposphere and that their magnitude de

the role of tectonic grain size reduction in the rheological stratification of the lithosphere with the aid of published constitutive flow laws for common crustal and upper mantle rock types it is possible to construct curves showing variation of rock strength with depth in the continental lithosphere assuming a particular crustal stratification of rock types and a particular geothermal gradient such exercises lead to the conclusion that marked changes in strength can occur at major petrological interfaces such as the moho discontinuity which are therefore likely to be associated with a tendency for major sub horizontal detachments to form constitutive flow laws used for such purposes are usually assumed to represent steady state flow at constant rock microstructure

asymmetrical pull aparts and foliation fish as kinematic indicators abstract from field observations asymmetrical boudins pinch and swell structures and ellipsoidal volumes of oblique foliation segments in anisotropic rocks lacking competent layers are potentially useful kinematic indicators in shear zones they are derived by the modification of initially symmetrical pull aparts and or layering by superposed layer parallel shearing the response of boudins to such shear is a synthetic flow of those corner volumes lying within the extensional quadrants of the kinematic framework of the deformation into the inter boudin gaps type 1 asymmetrical pull aparts the response of pinch and swell structure is a back rotation of the swells to form type 2 asymmetrical pull aparts discrete extensional shears in the pinches may be either absent type 2a or present type 2b analogues of types 2a and 2b asymmetrical pull aparts occur in anisotropic materials with no compositionally distinct competent members where ellipsoidal volumes contain back rotated foliation segments foliation fish the field based kinematic interpretation was successfully tested by laboratory experiment wherein initially symmetrical trains of pre formed competent internally anisotropic boudins and pinch and swell structures were deformed in bulk simple shear a mechanical model is presented in terms of two material properties of the inclusions competence viscosity and internal rheological anisotropy in an attempt to account for the observed flow in the experiments and the deduced flow and kinematic significance of the natural examples in the presence of angular corners and associated geometrical stress concentrations competence viscosity controls the response to shear in the boudins in the absence of angular corners internal anisotropy controls the response to shear in the pinch and swell structures and in the foliation fish

the two dimensional response of a tropical jet to propagating lines of convection this paper uses simple one and two dimensional models to investigate the influence of a propagating line of convective forcing on a tropical jet representative of the african easterly jet the results are used to infer changes in the environment of the forcing region which would in reality tend to influence the evolution of the storm through convective mechanisms which are not resolved here from linear analytical solutions with a rigid lid it is found that the influence of the propagation of the forcing region is to intensify the response on the upstream side of the forcing this result is confirmed in two dimensional nonlinear simulations when linear wave modes are computed in a basic state that includes the jet structure small sensitivities to the basic state jet are found the two dimensional nonlinear model has been used further to compute the change in the environmental structure as a result of the forcing principally it is found that the modes of response to the forcing may be associated with characteristic changes in the basic state shear convective available potential energy cape and convective inhibition cin which would be expected to have significant influence on the convective system itself

modeled and observed variations in storm divergence and stratiform rain production in southeastern texas abstractstorm divergence profiles observed by an s band doppler radar are compared to ensemble simulations of 10 disparate precipitating systems occurring in warm season weakly baroclinic and strongly baroclinic environments in southeastern texas eight triply nested mesoscale model simulations are conducted for each case using single and double moment microphysics with four convective treatments i e two convective parameterizations and explicit versus parameterized convection at 9 km observed and simulated radar reflectivities are objectively separated into convective stratiform and nonprecipitating anvil columns and comparisons are made between ensemble mean echo coverages and levels of nondivergence lnds in both the model and observations storms occurring in less baroclinic environments have more convective rain area less stratiform rain area and more elevated divergence profiles the model ensemble and observations agree best for well organized leading line trailing stratiform systems

vertical mode decompositions of 2 day waves and the madden julian oscillation abstract vertical structures of 2 day waves and the madden julian oscillation mjo are projected onto vertical normal modes for a quiescent tropical troposphere three modes capture the gross tropospheric structure of 2 day waves while only two modes are needed to represent most of the baroclinic structure of the mjo deep circulations that project onto the first baroclinic mode are associated with deep cumulonimbus and stratiform rainfall shallow circulations that project onto higher wavenumber modes are associated with precipitating shallow cumulus and congestus and stratiform rainfall for both disturbances the horizontal divergence contributed by shallow modes is an important factor in the column integrated moist enthalpy budget these modes converge moist static energy for a time prior to when deep circulations export moist static energy these results highlight the importance of properly representing the effects of shallow cumulus congestus and stratiform precipitation in theories of convective

isolating spatiotemporally local mixed rossby gravity waves using multi dimensional ensemble empirical mode decomposition tropical waves have relatively large amplitudes in and near convective systems attenuating as they propagate away from the area where they are generated due to the dissipative nature of the atmosphere traditionally nonlocal analysis methods such as those based on the fourier transform are applied to identify tropical waves however these methods have the potential to lead to the misidentification of local wavenumbers and spatial locations of local wave activities to address this problem we propose a new method for analyzing tropical waves with particular focus placed on equatorial mixed rossby gravity mrg waves the new tropical wave analysis method is based on the multi dimensional ensemble empirical mode decomposition and a novel spectral representation based on spatiotemporally local wavenumber frequency and amplitude of waves we first apply this new method to synthetic data to demonstrate the advantages of the method in revealing characteristics of mrg waves we further apply the method to reanalysis data 1 to identify and isolate the spatiotemporally heterogeneous mrg waves event by event and 2 to quantify the spatial inhomogeneity of these waves in a wavenumber frequency energy diagram in this way we reveal the climatology of spatiotemporal inhomogeneity of mrg waves and summarize it in wavenumber frequency domain the indian ocean is dominated by mrg waves in the period range of 8 12 days the western pacific ocean consists of almost equal energy distribution of mrg waves in the period ranges of 3 6 and 8 12 days respectively and the eastern tropical pacific ocean and the tropical atlantic ocean are dominated by mrg waves in the period range of 3 6 days the zonal wavenumbers mostly fall within the band of 4 15 with indian ocean has larger portion of higher wavenumber smaller wavelength components mrg waves

a model for convectively coupled tropical waves nonlinearity rotation and comparison with observations abstract recent observational analysis of both individual realizations and statistical ensembles identifies moist convectively coupled kelvin waves in the tropics with supercluster envelopes of convection this observational analysis elucidates several key features of these waves including their propagation speed of roughly 15 m s 1 and many aspects of their dynamical structure this structure includes anomalously cold temperatures in the lower troposphere and warm temperatures in the upper troposphere below 250 hpa within and sometimes leading the heating region and strong updrafts in the wave and an upward and westward tilting structure with height below roughly 250 hpa other key features in the wave are that anomalous increases in convective available potential energy cape and surface precipitation lead the wave while the trailing part of the supercluster is dominated by stratiform precipitation the main result in this paper is the development of a simple model convective parameterization with n

contrasting styles of deformation during progressive nappe stacking at the southeastern margin of the bohemian massif thaya dome abstract variscan nappe stacking at the southeastern margin of the bohemian massif is a polyphase process implying a progressive modification of the deformation regime from thrusting to wrenching associated change of finite strain axes orientations and progressive downwards migration of thrust or wrench planes a first high temperature deformation phase d 1 is related to nappe stacking of moldanubian units in a nw se direction it is recorded only in these units d 2 corresponds to the piling of the moldanubian units over the moravian ones producing internal nappe stacking of the latter and a first medium temperature mylonitization of thaya basement rocks the main feature of this stage is a switch in finite strain axes orientation and northeastward transpressional shearing strain partitioning is important within the moravian nappes and implies alternation of plane strain oblate and constrictional fabrics d 3 is also a phase connected with strong non coaxial ne directed shearing it is concentrated in zones of weakness and causes reactivation of older structures the structural pattern strongly depends on the position in the nappe pile strike slip tectonics dominate near the resistant eastern cadomian basement border foliation parallel extensional reactivation producing large scale folds is typical in moravian nappes while extensional tectonics prevail in the uppermost gfohl nappe large scale strain partitioning during d 2 stacking of moravian nappes and the extension of the upper part of the nappe pile during d 3 reactivation are mechanically controlled by a lateral ramp basement geometry along the bruno vistulian cadomian foreland

estimates of large scale divergence in the lower troposphere over the western equatorial pacific a network of 915 mhz wind profilers measured half hourly lower tropospheric winds over the western equatorial pacific with vertical resolutions as high as 100 m during november 1992 through february 1993 the intensive observing period iop of the tropical ocean global atmosphere coupled ocean atmosphere response experiment toga coare these wind data are used in conjunction with collocated surface wind measurements to examine the near surface divergent flow over the western pacific warm pool during austral summer as well as the synoptic scale variability of divergence in both time and space the synoptic scale wind field estimated from profiler data exhibits stronger near surf ace divergence than sonde based estimates from the same time period temporal variations of the lower tropospheric divergence profiles are described by three vertical structure functions derived from varimax rotated eigenvector analysis one vertical mode appears to be associated with deep convection one with near surface processes and one with shallower convection these structure functions vary zonally across the coare region with the convective modes having convergence maxima at lower elevations to the west of the intensive flux array ifa than over and east of it