the interaction of the madden julian oscillation with the maritime continent in a gcm previous studies using the hadley centre coupled model hadcm3 have shown that the islands of the maritime continent act as an unrealistic block to the eastward propagation of the madden julian oscillation mjo this blocking effect is investigated using a simplified aqua planet version of this gcm with various idealized configurations of the maritime continent islands placed on the equator and an mjo like convective signal forced by a propagating sea surface temperature anomaly dipole results suggest that it is the orography of the islands rather than the presence of the islands themselves which results in the blocking of the mjo although the peak elevation of the orography in the gcm is very much lower than in reality it appears to act as effective block to the eastward propagation of the low level kelvin wave signal which accompanies the mjo in particular the representation of sumatra in the gcm as a north south oriented ridge straddling the equator seems to be particularly effective at blocking the kelvin wave signal which in a full gcm would result in the weakening or complete extinction of the mjo signal to the east of the maritime continent

multiscale aspects of convective systems associated with an intraseasonal oscillation over the indonesian maritime continent abstract multiscale aspects of convective systems over the indonesian maritime continent in the convectively active phase of an intraseasonal oscillation iso during november 2002 are studied using geostationary meteorological satellite infrared data and ground based observational data from x band rain radar equatorial atmosphere radar l band boundary layer radar and upper air soundings at koto tabang kt 0 20 s 100 32 e 865 m above mean sea level west sumatera indonesia in the analysis period four super cloud clusters sccs horizontal scale of 2000 4000 km associated with an iso are seen to propagate eastward from the eastern indian ocean to the indonesian maritime continent the sccs are recognized as envelopes of convection composed of meso scale cloud clusters m ccs horizontal scale of 500 1000 km propagating westward when sccs reach the indonesian maritime continent the envelopes disappear but m ccs are clearly observed over sumatera the evolution and structure of a distinct

barrier effect on mjo propagation by the maritime continent in the mjo task force gewex atmospheric system study models abstractthe simulated madden julian oscillation mjo events in 27 general circulation models gcms are identified using an mjo tracking method the results suggest that the occurrence frequencies

laterally constrained inversion of ground roll from seismic reflection records seismic reflection data contain surface waves that can be processed and interpreted to supply shear wave velocity models along seismic reflection lines the coverage of seismic reflection data allows the use of automated multifold processing to extract high quality dispersion curves and experimental uncertainties in a moving spatial window the dispersion curves are then inverted using a deterministic laterally constrained inversion to obtain a pseudo 2d model of the shear wave velocity a monte carlo global search inversion algorithm optimizes the parameterization when the strategy is used with synthetic and field data consistent final models with smooth lateral variations are successfully retrieved this method constitutes an improvement over the individual inversion of single dispersion curves

active crustal deformation from the azores triple junction to the middle east the co seismic crustal deformation along the africa eurasia eurasia arabia plate boundary from the azores triple junction 30 w up to the karliova triple junction 41 e is examined based on the moment tensor summation of mainly post 1964 earthquakes with ms 5 0 strain rates range from 10 8 yr to 10 6 yr while values exceeding 10 7 yr were calculated for the back arc aegean area and for the north anatolian fault zone a remarkable stability in the azimuth of the component of compression and of extension is observed in the area that extends west of italy 17 e up to the azores triple junction along this region the deformation is taken up by compression along a mean direction of n140 with rates from 1 1 to 2 8 mm yr and by extension along a mean direction of n50 with rates from 2 4 to 12 0 mm yr at the gloria fault and in the surrounding area dextral strike slip motion occurs at a rate of 11 mm yr from sicily up to the eastern end of the hellenic arc the crust is compressed at azimuths in the range n20 n31 with an average value of 26 5 this compression is occurring at a rate of 1 21 mm yr with an average value of 9 8 mm yr in the back arc aegean area extension is occurring along a mean azimuth of n156 with a rate of 5 2 3 8 mm yr the average shortening rate along the convex side of the hellenic arc is 12 mm yr from the eastern end of the north anatolian fault 41 e up to the northern aegean trough extension along n68 n179 and compression along n158 n89 occurs which results in dextral strike slip motion the rate of extension reduces from east to west from 30 mm yr to 5 mm yr while the rate of compression reduces from 17 mm yr to 5 mm yr the northwards motion of arabia results in a n31 trending compression at a rate of 7 mm yr along the east anatolian fault zone

resolution dependence of the simulated precipitation and diurnal cycle over the maritime continent the maritime continent is a region of intense rainfall characterised by a strong diurnal cycle this study investigates the sensitivity of rainfall characteristics to resolution in a coupled regional climate model configuration in particular focusing on processes that modulate the diurnal cycle model biases are resolution dependent increasing resolution from 3 4 to 1 4 improves the mean state sea surface temperature and precipitation biases however at higher resolutions 1 12 rainfall becomes too strong in most areas daily maximum rainfall is simulated about 2 4 h earlier than in observations over both the land and the ocean with only small improvements over high topography at higher resolution we develop a technique to examine cross coastal processes associated with the rainfall diurnal cycle along all coastlines this is used to investigate the sensitivity of the diurnal cycle to resolution and to the direction of the prevailing wind during offshore prevailing winds most land rainfall is confined near the coastline and associated with a shallow land sea breeze circulation at all resolution though rainfall partly develops directly inland at 1 12 during onshore prevailing winds rainfall propagates from the coastline to the island interior at 1 4 and 1 12 whereas it appears directly over the island interior at 3 4 and this is associated with a deep convective cell across the coastline for all resolutions oceanic rainfall propagates far offshore during offshore prevailing winds at all resolutions whereas it tends to remain confined near the coastline under onshore prevailing winds condition particularly at higher resolution

new empirical relationships among magnitude rupture length rupture width rupture area and surface displacement source parameters for historical earthquakes worldwide are compiled to develop a series of empirical relationships among moment magnitude m surface rupture length subsurface rupture length downdip rupture width rupture area and maximum and average displacement per event the resulting data base is a significant update of previous compilations and includes the additional source parameters of seismic moment moment magnitude subsurface rupture length downdip rupture width and average surface displacement each source parameter is classified as reliable or unreliable based on our evaluation of the accuracy of individual values only the reliable source parameters are used in the final analyses in comparing source parameters we note the following trends 1 generally the length of rupture at the surface is equal to 75 of the subsurface rupture length however the ratio of surface rupture length to subsurface rupture length increases with magnitude 2 the average surface displacement per event is about one half the maximum surface displacement per event and 3 the average subsurface displacement on the fault plane is less than the maximum surface displacement but more than the average surface displacement thus for most earthquakes in this data base slip on the fault plane at seismogenic depths is manifested by similar displacements at the surface log linear regressions between earthquake magnitude and surface rupture length subsurface rupture length and rupture area are especially well correlated showing standard deviations of 0 25 to 0 35 magnitude units most relationships are not statistically different at a 95 significance level as a function of the style of faulting thus we consider the regressions for all slip types to be appropriate for most applications regressions between magnitude and displacement magnitude and rupture width and between displacement and rupture length are less well correlated and have larger standard deviation than regressions between magnitude and length or area the large number of data points in most of these regressions and their statistical stability suggest that they are unlikely to change significantly in response to additional data separating the data according to extensional and compressional tectonic environments neither provides statistically different results nor improves the statistical significance of the regressions regressions for cases in which earthquake magnitude is either the independent or the dependent parameter can be used to estimate maximum earthquake magnitudes both for surface faults and for subsurface seismic sources such as blind faults and to estimate the expected surface displacement along a fault for a given size earthquake

effects of surface orography and land sea contrast on the madden julian oscillation in the maritime continent a numerical study using echam5 sit abstractthis study uses the atmospheric general circulation model agcm echam5 coupled with the newly developed snow ice thermocline model echam5 sit to examine the effects of orography and land sea contrast on the madden julian oscillation mjo in the maritime continent mc during boreal winter the echam5 sit is one of the few agcms that realistically simulate the major characteristics of the mjo three experiments are conducted with realistic topography without orography and with oceans only in the mc region to evaluate the relative effects of orography and land sea contrast orography and land sea contrast have the following effects on the mjo in the mc 1 a larger amplitude 2 a smaller zonal scale 3 more realistic periodicity and stronger eastward propagating signals 4 a stronger southward detour during the eastward propagation 5 a distorted coupled kelvin rossby wave structure and 6 larger low level moisture convergence the existence of mountainous islands also enhances the mean w

role of maritime continent land convection on the mean state and mjo propagation abstractthe maritime continent mc region is known as a barrier in the life cycle of the madden julian oscillation mjo during boreal winter the mjo detours the equatorial mc land region sout

the alhama de murcia fault se spain a seismogenic fault in a diffuse plate boundary seismotectonic implications for the ibero magrebian region received 20 december 2002 revised 15 september 2003 accepted 26 september 2003 published 2 january 2004 1 the shortening between the african and the iberian plates is absorbed by a number of faults distributed over a very wide zone with very low slip rates and long periods of seismic loading thus a seismotectonic map based only on faults associated with seismicity or with expressive geomorphic features is incomplete it is possible to characterize seismogenic faults using paleoseismology first paleoseismological results based on trenching analysis in the eastern betics lorca totana segment of the alhama de murcia fault are presented the main paleoseismic parameters of this fault segment are 1 a minimum of two to three mw 6 5 7 earthquakes in the last 27 kyr shortly before 1650 a d between 830 and 2130 b c and shortly before 16 7 ka respectively with a mean recurrence period of 14 kyr and a very short elapsed time and 2 a net slip rate of 0 07 0 6 mm yr during the last 30 kyr these results were extrapolated to the rest of the known active faults in the eastern betics and were added to the slip rates of the active faults at the african margin the total slip rate of the transect which crosses de alhama de murcia fault in spain and reaches the cheliff basin algeria would represent 21 82 of the total shortening between africa and eurasia estimated from plate motion models and seismic moment summation a number of factors could account for this discrepancy 1 hidden seismogenic faults in the emerged areas 2 absence of correlation between current and late pleistocene slip rates 3 extensive small faults that are undetected and that absorb a significant amount of the deformation and 4 possible overestimation of the convergence rates index terms 7221 seismology paleoseismology 7230 seismology seismicity and seismotectonics 7215 seismology earthquake parameters 8150 tectonophysics plate boundary general 3040 keywords eastern betics alhama de murcia fault paleoseismology trenching seismotectonics plate boundary

neogene extensional collapse in the western mediterranean betic rif alpine orogenic belt implications for the genesis of the gilbraltar arc and magmatic activity the betic rif orogenic belt crops out in the western mediterranean and constitutes the westernmost part of the alpine edifice the building up of this belt by compressional nappe tectonics occured during a series of alpine deformational episodes subsequent neogene extension resulted from the collapse of the previous compressional edifice through major extensional detachment systems this episode was accompanied by cafe alkaline to shoshonitic and lamproitic volcanism tectonic denudation of metamorphic core complexes and emplacement of peridotite bodies as a final consequence of the evolution of detachment systems furthermore we relate the generation of the gibraltar arc and the opening of the alboran sea to this major extensional event finally two main stages of tectonic denudation of these detachment systems are defined 1 nevado filabride stage with ex humation of metamorphic core complexes and 2 ronda beni boussera stage with a more advanced degree of denudation leading to the exhumation of upper mantle peridotites which may be tentatively termed mantle core complexes

the role of topographically induced vortices in tropical cyclone formation over the indian ocean abstractthe role of sumatra and adjacent topographic features in tropical cyclone tc formation over the indian ocean io is investigated sumatra as well as the malay peninsula and java have mountainous terrain that partially blocks low level flow under typical environmental stratification for easterly low level flow these terrain features often produce lee vortices some of which subsequently shed and move westward from the northern and southern tips of sumatra and thence downstream over the io since sumatra straddles the equator extending in a northwest southeast direction from approximately 6 n to 6 s the lee vortices while counter rotating are both cyclonic hence they can serve as initial disturbances that eventually contribute to tc formation over the io in addition low level equatorial westerly flow impinging on sumatra is also typically blocked and diverges at times contributing to cyclonic circulations over the io primarily near the southern end of the island data from two recen

temporal clustering of paleoseismic events on the oued fodda fault algeria paleoseismic investigations of the oued fodda fault which underwent surface fault rupture during the algeria earthquake of october 10 1980 m s 7 3 indicate that the average recurrence interval based on the long term geologic slip rate past 100 ka is at least an order of magnitude longer than the intervals between recent surface faulting events which are determined by radiocarbon dating of faulted colluvial deposits exposed in trenches across the fault evidence from trenches excavated across the 1980 surface rupture indicates that there have been at least three and possibly four surface faulting events on the oued fodda fault during the past 1 5 ka including the 1980 earthquake the ages of the three most recent events are well constrained the most recent event occurred in 1980 a surface faulting event occurred before 320 220 c 14 yr b p radiocarbon years before 1950 and after 875 240 yr b p and another event occurred just prior to deposition of a layer containing charcoal dated at 875 250 yr b p i e about 900 yr ago the average interval between the three most recent surface faulting events on the oued fodda fault was about 450 yr the cumulative slip on the oued fodda fault was produced by relatively short episodes characterized by frequent displacements surface faulting events every few hundred years separated by long periods of quiescence lasting several thousands to tens of thousands of years

low froude number flow past three dimensional obstacles part i baroclinically generated lee vortices abstract we study the flow of a density stratified fluid past a three dimensional obstacle using a numerical model our special concern is the response of the fluid when the froude number is near or less than unity linear theory is inapplicable in this range of froude number and the present numerical solutions show the rich variety of phenomena that emerge in this essentially nonlinear flow regime two such phenomena which occupy parts i and ii of this study are the formation of a pair of vertically oriented vortices on the lee side and a zone of flow reversal on the windward side of the obstacle the ice vortices have been explained as a consequence of the separation of the viscous boundary layer from the obstacle however this boundary layer is absent by design in the present experiments and lee vortices still occur we argue that a vertical component of vorticity develops on the lee side owing to the tilting of horizontally oriented vorticity produced baroclinically as the isentropes deform in r

a diagnostic study of the evolution of the mjo from indian ocean to maritime continent wave dynamics versus advective moistening processes abstractthe evolution processes for propagating madden julian oscillations with strong magnitude over the indian ocean io and maritime continent mc are investigated through a diagnosis of ecmwf reanalysis data for november april 1982 2011 a scale separated lower tropospheric 1000 700 hpa moisture budget is analyzed for four stages of composite life cycle suppressed cloud developing convective and decaying overall the budgets in the io and mc are dominated by wave induced boundary layer convergence in the anomalous easterlies wc and advection starting from the suppressed stage in the central io moistening by wc and advection by easterly anomalies contributes to an initiation of the mjo convection in the western io while surface evaporation and or shallow convection moistens the central io in the following cloud developing and convective stage in the central io moistening by wc and advection by the downstream kelvin rossby wave east of central io lead to eastward propagation of deep conve

a madden julian oscillation event realistically simulated by a global cloud resolving model a madden julian oscillation mjo is a massive weather event consisting of deep convection coupled with atmospheric circulation moving slowly eastward over the indian and pacific oceans despite its enormous influence on many weather and climate systems worldwide it has proven very difficult to simulate an mjo because of assumptions about cumulus clouds in global meteorological models using a model that allows direct coupling of the atmospheric circulation and clouds we successfully simulated the slow eastward migration of an mjo event topography the zonal sea surface temperature gradient and interplay between eastward and westward propagating signals controlled the timing of the eastward transition of the convective center our results demonstrate the potential making of month long mjo predictions when global cloud resolving models with realistic initial conditions are used

goringe alboran tell tectonic zone a transpression system along the africa eurasia plate boundary neotectonic structures distributed from the goringe bank to the tell atlas mountains show that the africa eurasia plate boundary in the western mediterranean corresponds to an east west trending deforming zone goringe alboran tell main pliocene and quaternary tectonic structures of the northern atlas mountains are northeast southwest striking fault related folds similar to that of el asnam and are related to north south to northwest southeast compressional movements active tectonics in agreement with the main seismicity distribution and focal mechanisms also support an oblique plate convergence and the existence of a 50 100 km wide transpression zone from goringe across alboran to the tell atlas mountains a kinematic model shows the interaction between dextral transcurrent faults and left lateral faults with block rotations and no lateral extension pinned model shortening and lateral movement rates during the quaternary are estimated to be 1 0 2 3 mm yr and block rotation rate is estimated as 2 5 3 9 m y the plate boundary may correspond to a transpression zone active thrust faults being controlled by deep seated dextral transcurrent faults

non uniqueness with refraction inversion a syncline model study non uniqueness occurs with the 1d parametrization of refraction traveltime graphs in the vertical dimension and with the 2d lateral resolution of individual layers in the horizontal dimension the most common source of non uniqueness is the inversion algorithm used to generate the starting model this study applies 1d 1 5d and 2d inversion algorithms to traveltime data for a syncline 2d model in order to generate starting models for wave path eikonal traveltime tomography the 1d tau p algorithm produced a tomogram with an anticline rather than a syncline and an artefact with a high seismic velocity the 2d generalized reciprocal method generated tomograms that accurately reproduced the syncline together with narrow regions at the thalweg with seismic velocities that are less than and greater than the true seismic velocities as well as the true values it is concluded that 2d inversion algorithms which explicitly identify forward and reverse traveltime data are required to generate useful starting models in the near surface where irregular refractors are common the most likely tomogram can be selected as either the simplest model or with a priori information such as head wave amplitudes the determination of vertical velocity functions within individual layers is also subject to non uniqueness depths computed with vertical velocity gradients which are the default with many tomography programs are generally 50 greater than those computed with constant velocities for the same traveltime data the average vertical velocity provides a more accurate measure of depth estimates where it can be derived non uniqueness is a fundamental reality with the inversion of all near surface seismic refraction data unless specific measures are taken to explicitly address non uniqueness then the production of a single refraction tomogram which fits the traveltime data to sufficient accuracy does not necessarily demonstrate that the result is either correct or the most probable

landscape response to strike slip faulting linked to collisional settings quaternary tectonics and basin formation in the eastern betics southeastern spain abstract neotectonic behaviour of the eastern betics southeastern spain has been controlled by the presence of a large left lateral shear zone this is an intraplate transcurrent zone probably decoupled by a mid crustal detachment horizon the morphological expression of this crustal structure is a sigmoidal corridor in which the main quaternary basins are located three types of morphostructural domains can be distinguished in the sigmoidal corridor the central segment and the northern and southern terminal splays the central segment is characterized by wrench tectonics whilst the southern and northern terminal splays are controlled by transtensional and transpressional tectonics respectively the quaternary morphostructural pattern is only the more recent picture of the tectonic processes that have controlled the late orogenic evolution of the eastern betics the indentation of the aguilas arc accompanied by thin skinned thrusting and tectonic escape in its easternmost sector and extensional collapse accompanied by thin skinned stretching in its westernmost sector

a multiscale model for the intraseasonal impact of the diurnal cycle over the maritime continent on the madden julian oscillation abstractthe eastward propagating madden julian oscillation mjo typically exhibits complex behavior during its passage over the maritime continent sometimes slowly propagating eastward and other times stalling and even terminating there with large amounts of rainfall this is a huge challenge for present day numerical models to simulate one possible reason is the inadequate treatment of the diurnal cycle and its scale interaction with the mjo here these two components are incorporated into a simple self consistent multiscale model that includes one model for the intraseasonal impact of the diurnal cycle and another one for the planetary intraseasonal circulation the latter model is forced self consistently by eddy flux divergences of momentum and temperature from a model for the diurnal cycle with two baroclinic modes which capture the intraseasonal impact of the diurnal cycle the mjo is modeled as the planetary scale circulation response to a moving heat source on the synoptic and planetary scales

constrained 1d joint inversion of seismic surface waves and p refraction traveltimes we present a joint inversion scheme that couples p wave refraction and seismic surface wave data for a layered subsurface an algorithm is implemented with a damped least squares approach the estimated parameters are s and p wave velocities and layer thicknesses while densities are assumed constant during inversion the coupling is both geometric and physical layer thicknesses are the same for sand p wave velocity profiles and p wave velocities enter in both forward algorithms sensitivity analysis performed on synthetic data reveals that surface wave dispersion curves can be sensitive also to p wave velocity of some layers especially for poisson s ratio values smaller than about 0 35 allowing synergic resolution of this parameter applications on both synthetic and field data show that the proposed approach mitigates the hidden layer problem of seismic refraction and leads to more accurate results than individual inversions also for surface waves additional constraints on the objective function on a priori poisson s ratio values allow unrealistic and not admissible vp and vs values to be avoided such constraints were applied in one field case considering the a priori information available about water table depth it is also shown that estimation of porosity can help the selection of the proper constraint on a priori poisson s ratio

role of topography on the mjo in the maritime continent a numerical case study the role of topography on a madden julian oscillation mjo event in the maritime continent mc is explored using a regional model four simulations are conducted lower resolution 12 km simulations using cumulus parameterization in the presence lr and absence lr flat of topography and higher resolution 4 km simulations without cumulus parameterization in the presence hr and absence hr flat of topography in the lr simulation the mjo remains unorganized with no clear eastward propagation while the lr flat simulation captures the mjo and its eastward propagation across the mc in the absence of cumulus parameterization both hr and hr flat capture the mjo and show several similarities and differences compared to the lr and lr flat simulations to better understand these differences a moisture budget analysis is conducted during the passage of the mjo in the lr flat simulation vertical advection of moisture is increased to the east of the islands leading to continuity in mjo associated convection continuity that was not present in the lr simulation the increase in vertical advection in the absence of topography is due to an increase in the mean moisture advection by the anomalous vertical winds in the middle of the mc horizontal advection seems to be the most important for an uninterrupted eastward propagation of the mjo the increase in the horizontal advection in the absence of topography is primarily due to an increase in the anomalous moisture advection by the mean zonal winds to what extent the mjo was influenced by the upstream effect from the new guinea topography was also explored these results indicate that the important physical processes for mjo associated convection may be different in different parts of the mc further implications of these results in the context of other recent studies on mjo propagation across the mc are discussed

circulation response to fast and slow mjo episodes abstractfast and slow madden julian oscillation mjo episodes have been identified from 850 and 200 hpa zonal wind and outgoing longwave radiation olr for 32 winters 16 october 17 march 1980 81 2011 12 for 26 fast cases the olr took no more than 10 days to propagate from phase 3 convection over the indian ocean to phase 6 convection over the western pacific for 8 slow cases the propagation took at least 20 days fast episode composite anomalies of 500 hpa height z500 show a developing rossby wave in the mid pacific with downstream propagation through mjo phases 2 4 changes in the frequency of occurrence of the nao weather regime are modest this rossby wave is forced by anomalous cooling over the maritime continent during phases 2 and 3 seen in phase independent wave activity flux the upper level anticyclonic response to phase 3 heating is a secondary source of wave activity the z500 slow episode composite response to mjo phases 1 and 2 is an enhanced aleutian low followed by a north a

contrasting characteristics between the northward and eastward propagation of the intraseasonal oscillation during the boreal summer abstract this study investigates the structural and evolutionary characteristics of the eastward and northward propagating intraseasonal oscillation iso in the indian ocean and western pacific during the boreal summer along the equator the near surface moisture convergence located to the east of the deep convection region appears to result in the eastward propagation of the iso consistent with the frictional wave cisk conditional instability of the second kind mechanism proposed in previous studies the eastward propagation is characterized by sequentially downstream development of deep convection occuring mainly in certain regions such as 60 95 120 and 145 e and the date line the northward propagation of deep convection can be attributed to the low level moisture convergence located to the north this convergence is a deep structure extending from the surface to the middle troposphere near surface convergence appears only after the systems approach the landmass in the north it is sugges

a case study of seismic zonation in municipal areas an earthquake of 7 4 magnitude in august 1999 caused major loss of life and severe damage within the municipality of izmit 170 km southeast of istanbul figure 1 a survey of the damaged buildings was made by the municipal authorities shortly after the earthquake the municipal government decided to conduct a pilot seismic zonation project to determine whether the cause of the damage was poor construction materials and methods or weak soil conditions in this project we investigated the soil conditions with two objectives in mind 1 to estimate the seismic model of the soil column at each district to determine the geotechnical earthquake engineering parameters and 2 to map active faults within the municipal area

improved parameterization to invert rayleigh wave data for shallow profiles containing stiff inclusions inversion of shear wave velocity profiles from phase velocity measurements of rayleigh wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer uncemented media is an application for which locating shallow stiff inclusions has important implications identification of the stiff layers is critical for foundation design and cost estimating of excavations a parameterization that seems adequate for this problem is to solve for anticipated high stiffness layers embedded in a coarser background profile that captures the general shear wave velocity trend of the study area the optimization is accomplished by using simulated annealing uncertainty measures resulting from the inversion are helpful for describing the influence of the parameterization on final model estimates

factors controlling rain on small tropical islands diurnal cycle large scale wind speed and topography abstracta set of idealized cloud permitting simulations is performed to explore the influence of small islands on precipitating convection as a function of large scale wind speed the islands are situated in a long narrow ocean domain that is in radiative convective equilibrium rce as a whole constraining the domain average precipitation the island occupies a small part of the domain so that significant precipitation variations over the island can occur compensated by smaller variations over the larger surrounding oceanic area while the prevailing wind speeds vary over flat islands three distinct flow regimes occur rainfall is greatly enhanced and a local symmetric circulation is formed in the time mean around the island when the prevailing large scale wind speed is small the rainfall enhancement over the island is much reduced when the wind speed is increased to a moderate value this difference is characterized by a change in the mechanisms by which convection is forced a thermally forced se

topographic effects on the eastward propagation and initiation of the madden julian oscillation abstract this study investigates the relationship between deep convection and heating anomaly in the madden julian oscillation mjo and the tropical topography the eastward propagation of the deep heating anomalies is confined to two regions the indian ocean and the western pacific warm pool superimposed on the eastward propagation is a series of quasi stationary deep heating anomalies that occur sequentially and discretely downstream in a leapfrog manner in the central indian ocean the maritime continent tropical south america and tropical africa the deep heating anomaly usually preceded by near surface moisture convergence and shallow heating anomalies tends to occur on the windward side of the tropical topography in these regions except the central indian ocean under the prevailing surface easterly anomaly of the mjo it is suggested that the lifting and frictional effects of the tropical topography and landmass induce the near surface moisture convergence anomaly which in turn triggers

barrier effect of the indo pacific maritime continent on the mjo perspectives from tracking mjo precipitation abstractexplanations for the barrier effect of the indo pacific maritime continent mc on the mjo should satisfy two criteria first they should include specific features of the mc namely its intricate land sea distributions and elevated terrains second they should include mechanisms for both the barrier effect and its overcoming by some mjo events guided by these two criteria a precipitation tracking method is applied to identify mjo events that propagate across the mc mjo c and those that are blocked by the mc mjo b about a half of mjo events that form over the indian ocean propagate through the mc most of them 75 become weakened over the mc the barrier effect cannot be explained in terms of the strength horizontal scale or spatial distribution of mjo convection when it approaches the mc from the west a distinction between mjo b and mjo c is their precipitation over the sea versus land in the mc region mjo c events rain much more over the sea than over land whereas rainfall over

shear wave measurements of the elasticity of the ground shear waves provide a direct way of determining the dynamic shear modulus of the ground that is independent of poisson s ratio two shear wave methods have been applied to determine in situ properties as a function of depth on three clay sites the first method was that of shear wave refraction using a strong shear wave source and an enhancement seismograph the second method measured the velocity of rayleigh or surface waves generated by vibrators on the surface of the ground in addition compression wave velocities were measured enabling the dynamic poisson s ratio to be calculated on all three sites the moduli were found to increase with depth they were compared with semi static values from plate tests and pressuremeter measurements the comparisons were made by means of a generalized viscoelastic model based on published values of damping for clays as a function of strain les ondes de cisaillement permettent de determiner directement le module de cisaillement dynamique du sol qui est independant du

earthquake induced flooding and paleoseismicity of the el asnam algeria fault related fold late quaternary activity of the el asnam thrust fault responsible for the october 10 1980 ms 7 3 earthquake and 36 km coseismic faulting is explored through diverse paleoseismological field methods we trenched through the main and secondary 1980 coseismic scarps made an analysis of earthquake induced flood deposits conducted a geomorphic study of leveling profiles and offset geological units across thrust and normal scarps and considered the geomorphology of the active fold twenty five radiocarbon ages from colluvial and alluvial deposits along with conventional fossils and artefacts dating of geological units show the timing of successive net vertical displacements on the thrust related fold and bending moment faults previous work showed that eight pre 1980 earthquakes occurred in clusters during the late holocene cumulative net vertical slip that amounts to 3 times the 1980 displacement is observed on multiple thrust fault scarps and offsets of geological units on bending moment faults maximum cumulative vertical displacements which are visible in different zones along the fault segments can reach 10 to 25 times the 1980 coseismic displacements the late quaternary uplift rate on the el asnam fault is 0 6 mm yr and taking into account slip variation along the fault this rate may range between 0 25 1 6 mm yr from which we obtain a shortening rate of 0 17 1 2 mm yr because the tell atlas mountains exhibit comparable seismogenic fault related folds with parallel and sequential structures of active faults a total average shortening rate of 2 05 mm yr during the late quaternary represents part of the convergence accommodated along the africa eurasia plate boundary

seismotectonics of the ibero maghrebian region abstract a study of the seismotectonics of the ibero maghrebian region is presented as deduced from main geological features seismicity and focal mechanism data the hypocentral distribution of shallow intermediate depth and deep earthquakes is analyzed the direction of the stress distribution is inferred from the focal mechanism of 24 selected events a seismotectonic framework summarizing these results together with the main geological features shows that a nw se general direction of horizontal compressive stresses is present in the region with a localized zone of horizontal tensions in the betics and the alboran sea the presence of intermediate depth and deep earthquakes is tentatively explained as caused by two consecutive processes of subduction

frictional moisture convergence in a composite life cycle of the madden julian oscillation abstract a composite life cycle of the madden julian oscillation mjo is constructed using an index based on the first two eofs of the bandpass filtered 20 80 days 850 mb zonal wind averaged from 5 n to 5 s every 2 5 around the equator precipitation 1000 mb convergence 850 mb wind and 200 mb wind are composited for the period 1979 95 water vapor integrated from the surface to 300 mb is composited for the period 1988 92 frictional moisture convergence at the equator is shown to play an important role in the life cycle of the madden julian oscillation mjo regions of boundary layer convergence foster growth of positive water vapor anomalies to the east of convection this convergence coincides with 850 mb easterly wind anomalies as is consistent with kelvin wave dynamics drying of the atmosphere occurs rapidly after the passage of convection with the onset of 850 mb westerly perturbations possible mechanisms for this drying include boundary layer divergence and subsidence or horizontal advect

topographic influence on the mjo in the maritime continent abstract this study demonstrates that during the passage of the mjo through the maritime continent in the boreal winter the corresponding deep convection and near surface wind anomalies tend to skirt around mountainous islands flow bifurcation around elongated mountainous islands such as new guinea is clearly seen topographic blocking generates distinctive vorticity and convergence distributions in this specific domain mountain wave like structures are also observed throughout the maritime continent with a clear spatial relationship with the high terrains in sumatra sulawesi and new guinea the existence of topography seems to create extra lifting and sinking within the large scale circulation and thus the convective system exhibits quasi stationary features near the major topography during the mjo passage through the maritime continent it is suggested that resolving the detailed topographic effects may play a key role in simulating realistic characteristics of the mjo in the maritime continent

why does the mjo detour the maritime continent during austral summer eastward propagation of the madden julian oscillation mjo detours the maritime continent mc region southward during austral summer exhibiting enhanced convective activity preferentially in the southern part of the mc area with much weaker anomalies in the central mc area column integrated moist static energy budget of the mjo is analyzed to understand the processes responsible for the mjo detouring results show that zonal and meridional moisture advection is the essential process to the mjo detouring causing the difference between the southern and central mc regions in the moisture recharge before and during the mjo onset further analysis reveals that moisture advection by mjo perturbation winds acting upon the background moisture gradient has the dominant contribution to the regional contrast between the central and southern mc areas the zonal moisture advection is greater in the southern mc region because the zonal gradient of the background moisture field is much steeper in the southern mc area than in the central mc area the onset of the australian monsoon in austral summer contributes to the establishment of the sharp zonal moisture gradient in the southern mc region the meridional moisture advection is weaker in the central mc area because meridional wind anomalies associated with the mjo vary regionally presumably through interactions with the topography and land sea contrast

convectively coupled equatorial waves within the mjo during cindy dynamo slow kelvin waves as building blocks this study examines the relationship between the mjo and convectively coupled equatorial waves ccews during the cindy2011 dynamo field campaign using satellite borne infrared radiation data in order to better understand the interaction between convection and the large scale circulation the spatio temporal wavelet transform stwt enables us to document the convective signals within the mjo envelope in terms of ccews in great detail through localization of space time spectra at any given location and time three mjo events that occurred in october november and december 2011 are examined it is in general difficult to find universal relationships between the mjo and ccews implying that mjos are diverse in terms of the types of disturbances that make up its convective envelope however it is found in all mjo events that the major convective body of the mjo is made up mainly by slow convectively coupled kelvin waves these kelvin waves have relatively fast phase speeds of 10 13 m s 1 outside of and slow phase speeds of 8 9 m s 1 within the mjo sometimes even slower eastward propagating signals with 3 5 m s 1 phase speed show up within the mjo which as well as the slow kelvin waves appear to comprise major building blocks of the mjo it is also suggested that these eastward propagating waves often occur coincident with n 1 wig waves which is consistent with the schematic model from nakazawa in 1988 some practical aspects that facilitate use of the stwt are also elaborated upon and discussed

high resolution simulation of mean convection and its intraseasonal variability over the tropics in the mri jma 20 km mesh agcm abstract tropical mean convection and its organization on different spatiotemporal scales in a simulation using the meteorological research institute japan meteorological agency mri jma global atmospheric general circulation model agcm at 20 km resolution tl959l60 has been investigated comparison with two lower resolution simulations of 120 km tl159l40 and 180 km tl95l40 shows that convection climatological fields and moist stability over the indian ocean and south pacific convergence zone are better represented in tl959l60 than in lower resolution simulations however the simulated three dimensional structure of the walker and hadley cells and the vertical structure of convective heating do not show marked improvement relative to lower resolution simulations the amplitude and phase speed of convectively coupled equatorial waves show that although the kelvin waves the observed hierarchical structure of cloud clusters associated with the madden julian oscillation mjo convection and th

joint inversion of seismic and electric data applied to 2d media abstractmethods based on the seismic p wave seismic surface wave and apparent resistivity are commonly used in the solution of several near surface problems however the solution nonuniqueness and the intrinsic limitations of these methods can cause inconsistency in the final results dispersion curves of surface waves p wave traveltimes and apparent resistivity data were jointly inverted to obtain internally consistent and more reliable final model of p and s wave velocities and resistivity a collection of 1d layered models was obtained by a deterministic joint inversion algorithm based on the laterally constrained inversion scheme the three data sets were jointly inverted imposing the same structure and poisson s ratio was introduced as a physical link between p and s wave velocities to better constrain the inversion no physical link was imposed between the resistivity and the seismic velocities the inversion algorithm was tested on synthetic data and then applied to a field case where bench

clouds associated with the madden julian oscillation a new perspective from cloudsat abstractthe evolution of total cloud cover and cloud types is composited across the madden julian oscillation mjo using cloudsat data for june 2006 may 2010 two approaches are used to define mjo phases 1 the local phase is determined at each longitude and time from filtered outgoing longwave radiation and 2 the global phase is defined using a popular real time multivariate mjo rmm index which assigns the tropics to an mjo phase each day in terms of local phase cloudsat results show a familiar evolution of cloud type predominance in the growing stages shallow clouds coexist with deep intense but narrow convective systems widespread cloud coverage and rainfall appear during the active phases becoming more anvil dominated with time and finally suppressed conditions return results are compared to the convectively coupled kelvin wave which has a similar life cycle to the mjo convection in the mjo tends to be modulated more by moisture variations compared to the kelvin wave in terms of globa

barrier effect of the indo pacific maritime continent on mjo propagation in observations and cmip5 models abstractthis study explores possible mechanisms for the barrier effect of the indo pacific maritime continent mc on mjo propagation in particular this study examines whether similar mechanisms

porosity of fluid saturated porous media from measured seismic wave velocities this paper presents a novel procedure for determining porosity in fluid saturated porous media from measured shear and dilatational wave velocities the method is developed using the theory of linear poroelasticity in the low frequency limit which is equivalent to considering the fluid saturated porous medium as a closed un drained system with the pore fluid moving in phase with the soil skeleton the new procedure for the in situ measurement of porosity has been applied at two sites in italy using cross hole seismic data the results obtained are in excellent agreement with independent laboratory data gathered from undisturbed soil specimens

convectively coupled kelvin wave propagation past sumatra a june case and corresponding composite analysis 1 the propagation of two sequential convectively coupled cc kelvin waves past sumatra in june 2006 is examined in reanalysis data and satellite observations rainfall data are presented that are consistent with a considerable damping of the first wave such damping is not unexpected however reanalysis data suggest that in some instances including the episode described here cc kelvin waves can condition the low level flow in a manner that promotes passage of subsequent waves past the island the mechanism involves a sustained northward shift in the low level equatorial westerly winds and the latitude of zero absolute vorticity generated as a cc kelvin wave passes for the june 2006 case kelvin wave filtered low level winds are presented which are consistent with the view that such conditioning associated with the first wave caused the second wave to be shifted northward assisting its eastward propagation a vorticity analysis points to the development of widespread low level divergence within a vortex to the west of sumatra and associated vortex expansion as key factors in the observed conditioning a composite analysis is presented for the region demonstrating recurring divergence events of this nature coupled with concomitant northward shifts in the dynamic equator it finds that such events often occur in association with cc kelvin waves though the climatological extent to which the propagation of successor waves is affected is not addressed possible causes of the observed divergence events including equatorial rossby waves and contributions from transitions to stratiform convection are investigated