the kinematic structure of hurricane gloria 1985 determined from nested analyses of dropwindsonde and doppler radar data abstract a set of three dimensional filtered multiply nested objective analyses has been completed for the wind field of hurricane gloria for 0000 utc 25 september 1985 at this time gloria was one of the most intense hurricanes ever observed in the atlantic basin with a minimum sea level pressure of 919 mb the nested analyses based on observations from airborne doppler radar and omega dropwindsondes simultaneously describe eyewall and synoptic scale features and are the most comprehensive analyses of a single hurricane constructed to date the analyses have been used to document the multiscale kinematic structure of gloria and to investigate the relationship between the kinematic fields and the motion of the vortex the analyses indicate that the vortex was unusually barotropic the radius of maximum wind rmw was nearly vertical below 500 mb with a slight inward slope with height between 750 and 550 mb the strongest azimuthal mean tangential winds were found well above the boundary layer near

numerical simulations of tropical cyclone ocean interaction with a high resolution coupled model the tropical cyclone ocean interaction was investigated using a high resolution tropical cyclone ocean coupled model the model design consisted of the noaa geophysical fluid dynamics laboratory tropical cyclone prediction model which was coupled with a multilayer primitive equation ocean model coupling between the hurricane and the ocean models was carried out by passing into the ocean model the wind stress heat and moisture fluxes computed in the hurricane model the new sea surface temperature sst calculated by the ocean model was then used in the tropical cyclone model a set of idealized numerical experiments were performed in which a tropical cyclone vortex was embedded in both easterly and westerly basic flows of 2 5 5 and 7 5 m s 1 with a fourth experiment run with no basic flow specified initially the profile of the tangential wind for hurricane gloria at 1200 utc 22 september 1985 was used as the initial condition of the tropical cyclone for each of the experiments the model ocean was initially horizontally homogenous and quiescent to clarify the impact of the ocean response to the hurricane s behavior analogous experiments were also carried out with the sst kept constant control cases the experiments indicated that the cooling of the sea surface induced by the tropical cyclone resulted in a significant impact on the ultimate storm intensity due to the reduction of total heat flux directed into the tropical cyclone above the regions of decreased sst the sea surface cooling produced by the tropical cyclones was found to be larger when the storms moved slower in the experiments run without an initial basic flow the maximum sst anomaly was about 5 6 c with a resulting difference in the minimum sea level pressure and maximum surface winds of 16 4 hpa and 7 m s 1 respectively in contrast in the experiments run with the 7 5 m s 1 basic flow the maximum sst anomalies ranged from about 2 6 to 3 0 c with a difference in the minimum sea level pressure and maximum surface winds of about 7 3 hpa and 2 7 m s 1 the tropical cyclone ocean coupling significantly influenced the storm track only for the case with no basic flow and the 2 5 m s 1 easterly flow in these cases the storm with the ocean interaction turned more to the north and east no basic flow or the north 2 5 m s 1 easterly flow of the experiments with constant sst in the first case the storm by 72 hours was located over 70 km to the east southeast of the control case a possible explanation for this track deviation is related to a systematic weakening of the mean tangential flow at all radii of the storm due to the interaction with the ocean and resulting alteration of the beta drift

volcaniclastic sediments process interaction and depositional setting of the mio pliocene miura group se japan abstract the mid miocene to early pliocene 14 3 ma miura group exposed on the miura and boso peninsulas around tokyo bay in southern honshu comprises at least a 2 km thick succession of volcaniclastic sediments these accumulated in a forearc basin or basins on the eastern side of a proto izu bonin arc prior to and during accretion of the miura block onto the honshu arc and its subsequent dextral transcurrent eduction the basin fill shows a complex admixture of facies that result from multiple processes which operated on a relatively shallow slope basin the main facies groups include dark coloured mostly coarse grained scoriaceous beds pale coloured muddy silty pumiceous bioturbated sediment yellowish and whitish coloured tuffaceous horizons and chaotic slump debris flow and injection units many of the facies and beds in the older misaki formation can be readily interpreted as the result of a direct pyroclastic fall through the air and water b downslope resedimentation via turbidity currents and related processes in some cases derived from subaqueous base surge pyroclastic flow or vertical density currents c hemipelagic settling commonly under the influence of thermohaline bottom currents in other cases composite beds are believed to result from the interaction of these processes in more complex events the younger hasse formation is dominated by more shallow water marine currents and storm events and in parts by fluvial or proximal fan delta processes the distribution of these different facies illustrates the evolution and shallowing of the miura boso forearc basins during accretion and emplacement

a high resolution simulation of typhoon rananim 2004 with mm5 part i model verification inner core shear and asymmetric convection abstract in this study the fifth generation pennsylvania state university national center for atmospheric research psu ncar mesoscale model mm5 is used to simulate typhoon rananim 2004 at high resolution 2 km grid size the simulation agrees well with a variety of observations especially for intensification maintenance landfall and inner core structures including the echo free eye the asymmetry in eyewall convection and the slope of the eyewall during landfall the asymmetric feature of surface winds is also captured reasonably well by the model as well as changes in surface winds and pressure near the storm center the shear induced vortex tilt and storm relative asymmetric winds are examined to investigate how vertical shear affects the asymmetric convection in the inner core region the inner core vertical shear is found to be nonunidirectional and to induce a nonunidirectional vortex tilt the distribution of asymmetric convection is however inconsistent with the typical downshear

doppler profiler and radar observations of boundary layer variability during the landfall of tropical storm gabrielle abstract detailed observations of boundary layer structure were acquired on 14 september 2001 prior to and during the landfall of tropical storm gabrielle the mobile integrated profiling system mips and the shared mobile atmospheric research and teaching radar smart r were collocated at the western florida coastline near venice very close to the wind center at landfall prior to landfall the boundary layer was rendered weakly stable by a long period of evaporational cooling and mesoscale downdrafts within extensive stratiform precipitation that started 18 h before landfall the cool air mass was expansive with an area within the 23 c surface isotherm of about 50 000 km2 east northeasterly surface flow transported this cool air off the west coast of florida toward the convergent warm core of the gabrielle and promoted the development of shallow warm and cold fronts that were prominent during the landfall phase airflow properties of the boundary layer around the coastal zone are examined using

analytical and numerical studies of the beta effect in tropical cyclone motion part i zero mean flow abstract the effect on tropical cyclone motion is studied using an analytical as well as a numerical model in a nondivergent barotropic framework the analytical model and the linear version of the numerical model give essentially the same result the linear effect causes a westward stretching of the model vortex but no significant movement of the vortex center an east west asymmetry in the meridional wind field is also created it is the inclusion of the nonlinear term that produces the northwestward movement of the vortex previously found by other investigators e g kitade 1981 this northwestward movement increases with both the maximum wind speed and the radius of maximum wind in a constant shape vortex a wind maximum is also found to the northeast of the vortex which appears to be consistent with the observational findings of shea and gray this asymmetry plays an important role in the vortex motion

on the influences of vertical wind shear on symmetric tropical cyclone structure derived from amsu abstract axisymmetric temperatures and gradient balanced winds associated with tropical cyclones derived from the advanced microwave sounding unit are stratified by the 24 h averaged vector difference of the horizontal wind between 200 and 850 hpa or vertical wind shear using 186 total cases that are limited to tropical cyclones with intensities greater than 33 m s 1 or mature and are located over sea surface temperatures greater than 26 4 c vertical wind shear based composites are created results show that as the vertical wind shear increased the upper level warm core structure associated with the tropical cyclone descended resulting in a shallower balanced vortex these observationally based results are presented in the context of recent mesoscale modeling results of the effect of shear on tropical cyclone structure

a balanced tropical cyclone test case for agcms with background vertical wind shear abstractthis paper presents a balanced tropical cyclone tc test case designed to improve current understanding of how atmospheric general circulation model agcm configurations affect simulated tc development and behavior it consists of an analytic initial condition comprising two independently balanced components the first provides a vortical tc seed while the second adds a planetary scale zonal flow with height dependent velocity and imposes background vertical wind shear vws on the tc seed the environmental flow satisfies the steady state hydrostatic primitive equations in spherical coordinates and is in balance with other background field variables e g temperature surface geopotential the evolution of idealized tcs in the test case framework is illustrated in 10 day simulations performed with the community atmosphere model version 5 1 1 cam 5 1 1 environmental wind profiles with different magnitudes directions and vertical inflection points are applied to ensure that the technique

a numerical study of the effect of island terrain on tropical cyclones abstract a triply nested movable mesh model was used to study the behavior of tropical cyclones encountering island mountain ranges the integration domain consisted of a 37 wide and 45 long channel with an innermost mesh resolution of 1 6 the storms used for this study were embedded in easterly flows of 5 and 10 m s 1 initially realistic distributions of island topography at 1 6 resolution were inserted into the model domain for the region of the caribbean including the islands of cuba hispaniola and puerto rico the island of taiwan and the region of luzon in the northern philippines it was found that the islands affected the basic flow as well as the wind field directly associated with the storm system the combination of these effects caused changes in the track and translational speed of the storm in particular in the case of the 5 m s 1 easterly flow the storm accelerated and veered to the north well before reaching taiwan for the other island distributions the northward deflecti

effects of asymmetric sst distribution on straight moving typhoon ewiniar 2006 and recurving typhoon maemi 2003 abstractthe effects of asymmetric sea surface temperature sst distribution on the tropical cyclone tc motion around east asia have been examined using the weather research and forecasting model for the straight moving typhoon ewiniar 2006 and recurving typhoon maemi 2003 the sst tc motion relationships associated with the two different tcs and the physical mechanism of recurvature are investigated in the context of the potential vorticity tendency framework a zonally asymmetric sst distribution alters the tc translating direction and speed which is ascribable to the interaction between a tc and the environmental current associated with asymmetric sst forcing a north south sst gradient has an insignificant role in the tc motion it is noted that the straight moving i e northward moving tc deflects toward the region of warmer sst when sst is zonally asymmetric a contribution of the horizontal advection including asymmetric flow induced by asymmetric forcing is dominant for the deflection t

continental subduction intracrustal shortening and coeval upper crustal extension p t evolution of subducted south iberian paleomargin metapelites betics se spain abstract the nevado filabride complex represents the basement and permo triassic cover of the south iberian passive margin metamorphosed during miocene continental subduction under the alboran crustal domain it forms a nappe stack with the thick calar alto unit 6 km thick sandwiched between the ragua unit below and the bedar macael unit above the nappe stacking occurred by ductile flow along basal syn metamorphic shear zones structural analysis of the calar alto unit together with thermobarometric data of samples from both the bottom and top of the unit served us to understand the tectonic significance of this episode of intracrustal shortening in the context of a strongly extended orogen multiequilibrium thermobarometry shows that the calar alto schist underwent a prograde p t path at mantle depths from 1 6 gpa at 450 500 c to 1 0 gpa at 550 570 c during the growth of the schistosity s1 parallel to the compositional layering after detachment from the downgoing slab and underplating the unit underwent nearly isobaric cooling by up to 250 c from peak metamorphic conditions the main crenulation cleavage s2 and the mylonitic foliation sm developed within the crustal nappe stack during decompression and heating sm at the base of the unit grew between 0 8 gpa at 400 c and 0 4 gpa at 500 c while s2 at the top of the unit developed between 0 6 gpa at 300 c and 0 2 gpa at 400 c these shortening structures developed simultaneously to the activity of overlying middle miocene extensional detachments intracrustal shortening and coeval upper crustal extension resulted in a mode of exhumation where the material rise entailed an important horizontal component of displacement at rates of approximately 15 mm year being exhumed along an s shaped p t path after peak metamorphic conditions and its detachment from the subducting slab

effects of vertical wind shear on the intensity and structure of numerically simulated hurricanes a series of numerical simulations of tropical cyclones in idealized large scale environments is performed to examine the effects of vertical wind shear on the structure and intensity of hurricanes the simulations are performed using the nonhydrostatic pennsylvania state university national center for atmospheric research fifth generation mesoscale model using a 5 km fine mesh and fully explicit representation of moist processes when large scale vertical shears are applied to mature tropical cyclones the storms quickly develop wavenumber one asymmetries with upward motion and rainfall concentrated on the left side of the shear vector looking downshear in agreement with earlier studies the asymmetries develop due to the storm s response to imbalances caused by the shear the storms in shear weaken with time and eventually reach an approximate steady state intensity that is well below their theoretical maximum potential intensity as expected the magnitude of the weakening increases with increasing shear all of the storms experience time lags between the imposition of the large scale shear and the resulting rise in the minimum central pressure while the lag is at most a few hours when the storm is placed in very strong 15 m s21 shear storms in weaker shears experience much longer lag times with th e5ms 21 shear case showing no signs of weakening until more than 36 h after the shear is applied these lags suggest that the storm intensity is to some degree predictable from observations of largescale shear changes in all cases both the development of the asymmetries in core structure and the subsequent weakening of the storm occur before any resolvable tilt of the storm s vertical axis occurs it is hypothesized that the weakening of the storm occurs via the following sequence of events first the shear causes the structure of the eyewall region to become highly asymmetric throughout the depth of the storm second the asymmetries in the upper troposphere where the storm circulation is weaker become sufficiently strong that air with high values of potential vorticity and equivalent potential temperature are mixed outward rather than into the eye this allows the shear to ventilate the eye resulting in a loss of the warm core at upper levels which causes the central pressure to rise weakening the entire storm the maximum potential vorticity becomes concentrated in saturated portions of the eyewall cloud aloft rather than in the eye third the asymmetric features at upper levels are advected by the shear causing the upper portions of the vortex to tilt approximately downshear the storm weakens from the top down reaching an approximate steady state intensity when the ventilated layer can descend no farther due to the increasing strength and stability of the vortex at lower levels

the evolution of hurricane humberto 2001 abstractin 2001 the national oceanic and atmospheric administration and the national aeronautical and space administration marshaled their resources to sample hurricane humberto for 3 successive days during the fourth convection and moisture experiment camex 4 humberto developed from a tropical storm into a category 2 hurricane despite the deep layer vertical shear of the environmental horizontal wind vws increasing markedly on the second and third days of sampling as exhibited in earlier studies the eyewall convection developed an azimuthal wavenumber 1 n 1 asymmetry as the vws increased horizontal divergence and vertical stability within 100 km of the eye exhibited persistent relationships to the vws vector the warm core evolved in an unexpected way the warm anomaly was initially located in the lower troposphere and built upward as the storm intensified the maximum temperature anomaly remained in the lower troposphere on all 3 days while the development of the upper tropospheric warm anom

asymmetric structures in a simulated landfalling hurricane abstract highly asymmetric structures in a landfalling hurricane can lead to the formation of heavy rains wind gusts and tornados at prefered locations relative to the center of the hurricane in this study the development of asymmetric structures in an explicitly simulated idealized hurricane during landfall was investigated it was found that the boundary layer friction and its associated convection produce a low level positive potential vorticity pv band ahead of the hurricane the interaction between the pv band and the eyewall pv ring leads to a temporary weakening and reintensifying cycle asymmetric structures arise from the near discontinuity of the surface friction and the latent heat flux the breaking of the eyewall in the rear quadrants is favorable for the intrusion of the low moist entropy air into the core consequently pv increases significantly in the core in and just above the boundary layer due to the stabilization after the hurricane makes landfall the diabatic heating in the

prediction and diagnosis of the motion and rapid intensification of typhoon sinlaku during tropical cyclone structure experiment 2008 tcs08 abstractthe impact of initial structure on storm evolution is examined for the case of a tropical storm entering rapid intensification at the onset of rapid intensification satellite cloud signatures suggest that the structural organization of typhoon sinlaku 2008 was dominated by a primary band of convection present at outer radii the development of the eyewall subsequently occurred within this band of deep convection numerical forecasts of sinlaku are initialized at 15 and 5 km resolution using a broad range of vortex scales at a time when the storm was still weak and its structure not clearly defined evidence is presented that beta propagation played a key role in changing the storm s motion under weak environmental steering it is found that the track forecast improves over the period when beta propagation is prominent if the vortex is initialized with a large radius of maximum wind rmw corresponding with the primary outer cloud band the initial vortex structure is also suggested to play a

hurricane juan 2003 part ii forecasting and numerical simulation abstract the landfall of hurricane juan september 2003 in the canadian maritimes represents an ideal case in which to study the performance of operational forecasting of an intense predominantly tropical feature entering the midlatitudes a hybrid cyclone during its genesis phase juan underwent a tropical transition as it drifted slowly northward 1500 km from the east coast of the united states shortly after reaching its peak intensity as a category 2 hurricane the storm accelerated rapidly northward and made landfall near halifax nova scotia canada with maximum sustained winds of 44 m s 1 although the forecasts and warnings produced by the u s national hurricane center and the canadian hurricane centre were of high quality throughout hurricane juan s life cycle guidance from numerical weather prediction models became unreliable as the storm accelerated toward the coast the short range near surface forecasts from eight operational models during the crucial prelandfall portion of juan s track

central japan triple junction a three dimensional compression model abstract we present a new interpretation of the tectonics of the trench trench trench triple junction off central japan using more specifically data obtained during the french japanese kaiko cruise in 1984 data analysis and consideration on the three dimensional geometry of the junction and its kinematics lead to the conclusion that the whole area undergoes large scale compressional intraplate deformation this is caused by the subduction of the philippine sea plate in the restricted space between the pacific and northern honshu plates we then apply the same analysis to the whole central japan area for which we consider the role of the interaction of the three plates at depth as a basis for tectonic reconstructions since the miocene

dual aircraft investigation of the inner core of hurricane norbert part i kinematic structure abstract on 24 25 september 1984 air motions and physical processes in the eyewall region of hurricane norbert were investigated with two national oceanic and atmospheric administration noaa aircraft operations center aoc wp 3d research aircraft one aircraft equipped with the airborne doppler radar flew repeated radial penetrations of the eyewall mapping the three dimensional wind field throughout a 40 km radius of the storm center these data provide the first complete documentation of the three dimensional wind field of the inner core of a hurricane on spatial scales of 10 25 km in the horizontal and 1 km in the vertical and temporal scales of 1 2 h the wind field was asymmetric and the asymmetry varied with altitude as altitude increased the location of the maximum tangential wind sloped upwind from left of the storm track at 1 km altitude to right of the storm track above 3 km the radial wind at 1 km altitude was inward in front of the storm and outward behind this pattern in the radial

low wavenumber structure and evolution of the hurricane inner core observed by airborne dual doppler radar abstract the asymmetric dynamics of the hurricane inner core region is examined through a novel analysis of high temporal resolution three dimensional wind fields derived from airborne dual doppler radar seven consecutive composites of hurricane olivia s 1994 wind field with 30 min time resolution depict a weakening storm undergoing substantial structural changes the symmetric and asymmetric mechanisms involved in this transformation are considered separately to zeroth order the weakening of the primary circulation is consistent with the axisymmetric vortex spindown theory of eliassen and lystad for a neutrally stratified atmosphere vertical shear however increased dramatically during the observation period leading to a strong projection of the convection onto an azimuthal wavenumber 1 pattern oriented along the maximum vertical shear vector recent theoretical ideas elucidating the dynamics of vortices in vertical shear are used to help explain this asymmetry the role of asymmetric vorticity d

tidal rhythmites in a deep sea environment an example from mio pliocene misaki formation miura peninsula japan abstract the mio pliocene misaki formation miura peninsula japan is characterized by alternation of mafic scoriaceous pebbly sandstone pumiceous sandstone and siltstone and mudstone formed in a fore arc basin in an arc arc collisional zone the qualitative as well as quantitative evidences of tide during the misaki sedimentation in the jogashima area miura peninsula are presented here the lunar synodic period of 28 days lunar month extracted from the misaki tidal rhythmite agrees well with the published miocene tidal rhythmite data the couplet series of the misaki tidal rhythmite however is often interrupted by downslope resedimentation via turbidity currents intense penecontemporaneous deformation and bioturbation association of deep sea turbidites mass flow deposits and tidal rhythmite suggest misaki sedimentation in the miura peninsula took place in a submarine canyon setting

interaction of a baroclinic vortex with background shear application to hurricane movement abstract most extant studies of tropical cyclone movement consider a barotropic vortex on a plane however observations have shown that real tropical cyclones are strongly baroclinic with broad anticyclones aloft also the distribution of the large scale potential vorticity gradient in the tropical atmosphere is very nonuniform these properties may substantially influence the movement of such storms note that the anticyclone above a hurricane will interact with the lower hurricane vortex and induce storm motion such interaction can be caused by both the direct effect of ambient vertical shear and the effect of vertical variation of the background potential vorticity gradient in this paper an attempt to isolate the effect of background vertical shear is made the hurricane is represented in a two layer quasigeostrophic model as a point source of mass and zero potential vorticity air in the upper layer collocated with a point cyclone in the lower layer the model is integrated by the method of co

ocean effects on tropical cyclone intensification and inner core asymmetries abstract the interaction between a tropical cyclone and the ocean is investigated using a minimal three dimensional tropical cyclone model coupled with a two layer ocean model two representations for entrainment into the ocean mixed layer are compared one based on the assumption that the velocity scale for entrainment is the surface friction velocity the other on the assumption that this scale is the magnitude of the mean velocity difference across the base of the mixed layer it is shown that the magnitude and distribution of the ocean cooling depends strongly on the method for representing entrainment velocity the method based on the surface friction velocity is more effective in reducing the heat flux from the ocean to the storm in the inner core region and leads to a greater reduction of the tropical cyclone intensity with ocean coupling the surface heat flux is reduced in the inner core mainly in the rear right quadrant relative to the track which is toward the northwest as a result the pot

the effect of relative flow on the asymmetric structure in the interior of hurricanes abstract asymmetric structure of tropical cyclones simulated by the geophysical fluid dynamics laboratory high resolution triply nested movable mesh hurricane model was analyzed emphasis was placed on the quasi steady component of the asymmetric structure in the region of the eyewall it was found that the asymmetry was primarily caused by the relative wind that is the flow entering and leaving the storm region relative to the moving storm a set of idealized numerical experiments was first performed both with a constant and a variable coriolis parameter f and the addition of basic flows that were either constant or sheared with height analysis was then made for one case of hurricane gilbert 1988 to demonstrate that the quasi steady asymmetric structure analyzed in the idealized studies could be identified in this real data case vorticity analysis in the variable f experiment indicated that quasi steady asymmetries resulted in the eyewall region through the effect of vorticity advection due to

asymmetric hurricane boundary layer structure from dropsonde composites in relation to the environmental vertical wind shear this study investigates the asymmetric structure of the hurricane boundary layer in relation to the environmentalverticalwind shearin theinner core region data from1878 gps dropsondesdeployed by research aircraft in 19 hurricanes are analyzed in a composite framework kinematic structure analyses based on doppler radar data from 75 flights are compared with the dropsonde composites shear relative quadrantmeancomposite analysesshow that boththekinematicandthermodynamic boundarylayerheight scalestend to decrease with decreasing radius consistent with previous axisymmetric analyses there is still a clear separation between the kinematic and thermodynamic boundary layer heights both the thermodynamic mixed layer and height of maximum tangential wind speed are within the inflow layer the inflow layer depth is found to be deeper in quadrants downshear with the downshear right dr quadrant being the deepest the mixed layer depth and height of maximum tangential wind speed are alike at the eyewall but are deeper outside in quadrants left of the shear the results also suggest that air parcels acquire equivalent potential temperature ue from surface fluxes as they rotate through the upshear right ur quadrant from the upshear left ul quadrant convection is triggered in the dr quadrant in the presence of asymmetric mesoscale lifting coincident with a maximum in ue energy is then released by latent heating in the downshear left dl quadrant convective downdrafts bring down cool and dry air to the surface and lower ue again in the dl and ul quadrants this cycling process may be directly tied to shear induced asymmetry of convection in hurricanes

on hurricane outflow structure abstract flow fields from the model of wu and emanuel are presented it is demonstrated that the interaction of background shear with a uniform source of low potential vorticity air at the storm top can produce many of the observed characteristics of hurricane outflow including outflow jets our model is compared to other extant models of hurricane outflow

evolution of the structure of precipitation in hurricane allen 1980 abstract reflectivity data from the airborne radar systems on board the three noaa aircraft were gathered during six consecutive days in hurricane allen of 1980 the data have been used to specify the horizontal and vertical precipitation distribution within 111 km radius of the hurricane center the evolution of the structure and intensity of the precipitation in the storm is described from representative time composite radar maps for seven research flights made during the 6 day period the eyewall was characterized by a narrow ring 12 15 km wide of intense reflectivity 42 47 dbz surrounding the center of the storm at a radius that varied in time from 12 40 km the eyewall had steep radial gradients of reflectivity 4 5 db km 1 and tilted radially outward in height the rainbands were characterized by areas of enhanced reflectivity embedded in a region of stratiform rainfall that contained a distinct bright band at the height of the 0 c isotherm the most striking changes in structure during the 6 d

the relationship between storm motion vertical wind shear and convective asymmetries in tropical cyclones abstract the influence of the direction of storm motion on the azimuthal distribution of electrified convection in 35 atlantic basin tropical cyclones from 1985 to 1999 was examined using data from the national lightning detection network in the inner 100 km flashes most often occurred in the front half of storms with a preference for the right front quadrant in the outer rainbands r 100 300 km flashes occurred predominantly to the right of motion although the maximum remained in the right front quadrant the results are shown to be consistent with previous studies of asymmetries in rainfall radar reflectivity and vertical motion with respect to tropical cyclone motion the motion effect has been attributed to the influence of asymmetric friction in the tropical cyclone boundary layer the authors previously found a strong signature in the azimuthal distribution of lightning with respect to vertical wind shear because both effects show clearly vertical wind shear and storm motion must themse

geohazards in coastal areas near the northernmost sagami trough central japan review of neotectonic activity in onshore and offshore areas of the izu island arc collision subduction zone

vortex rossby waves in a numerically simulated tropical cyclone part i overall structure potential vorticity and kinetic energy budgets abstract the asymmetric structure in the inner core of a numerically simulated tropical cyclone is analyzed in this study the simulated tropical cyclone is found to be highly asymmetric in the inner core in the mid lower troposphere the asymmetry in the core is dominated by azimuthal wavenumber 1 and wavenumber 2 vortex rossby waves these waves propagate azimuthally upwind against the azimuthal mean cyclonic tangential flow around the eyewall and thus have a much longer cyclonic rotation period by a factor of 2 than the period of a parcel moving with the cyclonic mean tangential flow around the circumference they also propagate outward against the boundary layer inflow of the azimuthal mean cyclone the waves are only visible within a radius of about 60 km from the cyclone center beyond this distance the radial gradient of potential vorticity pv of the azimuthal mean cyclone is too weak to support the vortex rossby waves although the divergent motion remains strong the geopotential height an

a numerical study of convective scale structures in the outer cores of sheared tropical cyclones 1 updraft traits in different vertical wind shear magnitudes

hurricane vortex motion and evolution in a three layer model abstract a three layer multinested numerical model is used to evaluate the asymmetric evolution of a hurricane and its interaction with the large scale environment the model uses a compressible fluid in isentropic coordinates in 72 h the hurricane vortex on a beta plane moves northwest at an average speed of 2 4 m s 1 in the presence of a westerly zonal wind in the upper model layer the hurricane on an f plane moves to the southeast at an average speed of 0 9 m s 1 a series of experiments establishes that the southeastward drift in the presence of westerly shear is primarily due to the southward isentropic gradient of background potential vorticity pv in the middle model layer that is associated with the background temperature field the cyclonic circulation advects low pv air southward on the west side of the vortex inducing a negative isentropic pv anomaly to the southwest this anomaly is associated with a wind field that advects the vortex to the southeast just as the northward isentropic grad

an analytical theory of tropical cyclone motion using a barotropic model abstract an analytical theory is presented for the motion of an initially symmetric barotropic vortex on a beta plane at rest the prototype problem in the theory of tropical cyclone motion in the case of vortices with parameter values appropriate to tropical cyclones the theory shows excellent agreement with equivalent numerical model calculations for a period of between one and two days in particular the vortex track and the evolution of vortex asymmetries the so called beta gyres are accurately predicted the calculations provide further insight into dynamics of tropical cyclone motion in general and provide a firmer basis for interpreting the numerical solutions in particular they are relevant also to the important problem of designing more appropriate bogus vortices for the initialization of dynamically based tropical cyclone forecast models

oblique and near collision subduction sagami and suruga troughs preliminary results of the french japanese 1984 kaiko cruise leg 2 abstract leg 2 of the french japanese 1984 kaiko cruise has surveyed the suruga and the sagami troughs which lie on both sides of the northwestward moving and colliding izu bonin ridge the northernmost part of the philippine sea plate the transition from the nankai trough to the suruga trough is characterized by northward decrease in width of the accretionary prism in good agreement with the increasing obliquity between the through axis and the direction of the convergence as the strike of the convergent boundary changes from ene nne to south north south of the area the southern margin of the zenisu ridge shows contractional deformations this supports the interpretation made by the team of leg 1 who studied the western extension of the area we studied that it is an intra oceanic thrusting of the ridge over the shikoku basin in the sagami trough where the relative motion is highly oblique to the plate boundary active subduction is mostly confined in the east west trending portions of the trough located south of the boso peninsula and along the lower boso canyon near the ttt triple junction in between the present motion is mainly right lateral along the northwest trending boso escarpment however an inactive but recent pliocene to lower pleistocene accretionary prism exists south of the boso escarpment which suggests that the relative motion was more northerly than at present before about 1 ma ago

collision of the izu arc with honshu and the effects of oblique subduction in the miura boso peninsulas abstract collision of the izu arc in central japan is discussed with a focus on its tectonic effects to the east of the arc in the miura boso peninsulas of honshu the tectonics are the combination of the following events philippine sea plate spreading in the late oligocene to early miocene opening of the sea of japan in the middle miocene obduction of ophiolitic rocks in the northeasternmost corner of the philippine sea plate and forearc sedimentation between the honshu and izu arcs oblique subduction has shifted the plate boundary from northeast to southwest from the present mineoka tectonic belt through the miura fold belt to the sagami trough since the miocene remarkable right lateral transpressional deformation occurred throughout this period of the oblique collision and subduction

a composite analysis of the core of a mature hurricane abstract an unusually large quantity of aircraft data was obtained within the core of hurricane frederic 1979 these data are combined with powell s surface observations of the same storm and composited the data are sufficiently abundant to allow three dimensional kinematic analyses of poorly documented parameters such as divergence and vertical velocity patterns of related but independently determined parameters such as radar reflectivities cloud water concentrations and kinematically derived vertical velocities agree well diagnostic budget analyses of sensible heat and angular momentum are computed for the storm inflow layer the analysis provides a unique quantitative picture of the inflow layer of a mature asymmetric hurricane the depth of the inflow layer decreases with decreasing radius as a result surface drag coefficients derived from angular momentum budgets do not appear to increase with increasing wind speed the sensible heat budget shows downward subgrid scale heat fluxes near cloud

structure and development of the sagami trough and the boso triple junction abstract the sagami trough is located at the particular plate margin where the izu forearc is subducted underneath the honshu forearc at its southeastern end the world s only known ttt type triple junction boso triple junction has developed several different kinds of basins occur in different segments along the sagami trough and at the triple junction the bathymetric geologic and geophysical data obtained during the kaiko project and from additional studies are summarized together with our onland studies we suggest that the right lateral oblique plate motion formed an eduction margin in the sagami basin while a normal subduction margin and an oblique subduction margin have been formed in the middle sagami trough basin these tectonic phenomena resulted from the long lasting compressional covergence between the philippine sea plate and eurasian plate since the early or middle miocene the north basin on the northeasternmost margin of the philippine sea plate near the boso triple junction has developed as a stretched basin due to the westward motion of the philippine sea plate with respect to the eurasian plate

prediction experiments of hurricane gloria 1985 using a multiply nested movable mesh model abstract the prediction capability of the gfdl triply nested movable mesh model with finest grid resolution of degree was investigated using several case studies of hurricane gloria 1985 during the period that the storm approached and moved up the east coast of the united states the initial conditions for these experiments were interpolated from an nmc t80 global analysis at 0000 utc 25 september and 1200 utc 22 september the integrations starting from 0000 utc 25 september were run 72 h while those starting on 1200 utc 22 september were run 132 h the lateral boundary conditions were obtained from either an integration of the nmc t80 forecast model or the t80 global analysis or were fixed to the initial value the model s predicted track of gloria for each integration was compared against the best track determined by the national hurricane center nhc for the case starting from 0000 utc 25 september using a forecasted boundary condition the model successfully forecasted significant acceler

a high resolution simulation of asymmetries in severe southern hemisphere tropical cyclone larry 2006 abstract advances in observations theory and modeling have revealed that inner core asymmetries are a common feature of tropical cyclones tcs in this study the inner core asymmetries of a severe southern hemisphere tropical cyclone tc larry 2006 are investigated using the fifth generation pennsylvania state university national center for atmospheric research mesoscale model mm5 and the kepert wang boundary layer model the mm5 simulated tc exhibited significant asymmetries in the inner core region including rainfall distribution surface convergence and low level vertical motion the near core environment was characterized by very low environmental vertical shear and consequently the tc vortex had almost no vertical tilt it was found that prior to landfall the rainfall asymmetry was very pronounced with precipitation maxima consistently to the right of the westward direction of motion persistent maxima in low level convergence and vertical motion formed ahead of the translating tc resul

tropical cyclone motion a comparison of theory and observation abstract the analytic predictions of tropical cyclone motion by holland are shown to be in very good agreement with observations in the australian southwest pacific region these results indicate that a combined linear asymmetric advection and divergence of earth and cyclone vorticity provides the main mechanism for tropical cyclone motion it is also shown that an accurate prediction requires a consideration of horizontal and vertical asymmetries in the wind field hence care needs to be taken in defining a steering current

effects of vertical wind shear and storm motion on tropical cyclone rainfall asymmetries deduced from trmm abstract vertical wind shear and storm motion are two of the most important factors contributing to rainfall asymmetries in tropical cyclones tcs global tc rainfall structure in terms of azimuthal distribution and asymmetries relative to storm motion has been previously described using the tropical rainfall measuring mission microwave imager rainfall estimates the mean tc rainfall distribution and the wavenumber 1 asymmetry vary with storm intensity and geographical location among the six oceanic basins this study uses a similar approach to investigate the relationship between the structure of tc rainfall and the environmental flow by computing the rainfall asymmetry relative to the vertical wind shear the environmental vertical wind shear is defined as the difference between the mean wind vectors of the 200 and 850 hpa levels over an outer region extending from the radius of 200 800 km around the storm center the wavenumber 1 maximum rainfall asymmetry is downshear left right in the northern

soft sediment deformation structures in the mio pliocene misaki formation within alternating deep sea clays and volcanic ashes miura peninsula japan abstract the mio pliocene misaki formation of the miura group miura peninsula japan shows an extremely wide variety of soft sediment deformation structures the most common deformation structures are load casts and associated flame structures dish and pillar structures synsedimentary faults multilobated convolutions chaotic deformation structures sedimentary veins and dykes and large scale slides and slump scars the formation which accumulated in a deep sea environment 2000 3000 m is well exposed in and around jogashima it consists of relative thin commonly dm scale alternations of deep marine fine grained sediments and volcanic ejecta that are as a rule coarse grained since the formation represents fore arc deposits of the izu bonin and the honsu arc collision zone it might be expected that tectonic activity also played a role as a trigger of the soft sediment deformation structures that abound in these sediments this is indicated indeed by the abundance of soft sediment deformations over large lateral distances that occur in numerous beds that are sandwiched between undeformed beds on the basis of their characteristics and the geological context these layers can be explained satisfactorily only by assuming deformation triggered by seismicity which must be related to the izu bonin and honsu arc collision the layers thus form deep marine seismites

intensification of tropical cyclone like vortices in uniform zonal background flows the effect of uniform zonal background flows on the intensification of tropical cyclone like vortices is investigated using a numerical three layer shallow water model that includes parametrizations of convection sea surface energy exchange and boundary layer friction calculations on an f plane showed that during the developing stage an initially weak vortex intensified more rapidly in the presence of a uniform zonal background flow compared to an environment at rest the uniform zonal background flow resulted in increased boundary layer convergence collocated with increased boundary layer mixing ratio as a result of surface moisture fluxes producing stronger convection and more rapid intensification after the vortex achieved hurricane strength in the presence of an easterly westerly background flow a region of convectively stable air formed to the south north of the vortex centre as a result of small values of surface moisture flux and the downward transport of relatively dry middle layer air this convectively stable air penetrated slowly into regions of boundary layer convergence thereby weakening convection and reducing the maximum intensity of the vortex compared to the case without background flow this effect was more pronounced for stronger background flows calculations on a plane showed that a westerly background flow is more favourable for intensification than an easterly background flow of the same strength in the former the vortex always moved into a region of convectively unstable air whereas in the latter the vortex progressively moved into a region of convectively stable air produced by subsidence and drying of the boundary layer because of the relatively high vortex drift speed in the easterly background flow case there was not sufficient time for surface moisture fluxes to moisten the boundary layer air rapidly enough to eliminate the convectively stable region ahead of the vortex resulting in the overall weakening of convective activity and a less intense storm than in the westerly flow case the foregoing calculations suggest that the imposed background flow affects the development of the vortices in the shallow water model by establishing an environment in which boundary layer convergence and surface moisture fluxes may interact to produce stratifications that either enhance or suppress convection the occurrence of which is necessary for the intensification of the vortices in the model

monsoonal influence on typhoon morakot 2009 part i observational analysis abstracttyphoon morakot made landfall on taiwan with a record rainfall of 3031 5 mm during 6 13 august 2009 while previous studies have emphasized the influence of southwesterly winds associated with intraseasonal oscillations and monsoon surges on moisture supply the interaction between morakot and low frequency monsoon flows and the resulting influence on the slow movement and asymmetric precipitation structure of the typhoon were examined observationally embedded in multi time scale monsoonal flows morakot generally moved westward prior to its landfall on taiwan and underwent a coalescence process first with a cyclonic gyre on the quasi biweekly oscillation time scale and then with a cyclonic gyre on the madden julian oscillation time scale the coalescence enhanced the synoptic scale southwesterly winds of morakot and thus decreased its westward movement and turned the track northward leading to an unusually long residence time in the vicinity of taiwan the resulting slow movement and collocation

rainfall characteristics of recurving tropical cyclones over the western north pacific abstracta dataset of 88 recurving western north pacific tropical cyclones from 2004 to 2015 is investigated for rainfall characteristics during their period of recurvature the tcs are categorized into two groups based on different large scale patterns from empirical orthogonal function analysis group 1 is characterized by an intense midlatitude baroclinic zone and close distance between the zone and tc while group 2 is characterized by a weaker midlatitude baroclinic zone and more remote distance between the zone and tc at the time of recurvature the results show the large scale environment has substantial impact on tc rainfall patterns in group 1 as the tc approaches and is embedded into the baroclinic zone a relatively strong interaction between the tc and midlatitudes occurs which is reflected by a rapid increase of environmental vertical wind shear and tc translation speed the alignment of the shear vector and motion vector and a sharp contrast of temperature and moisture higher rainfall an

a simulation study of the landfall of tropical cyclones abstract by use of a triply nested movable mesh model several ideal simulations of tropical cyclone landfall were performed for a strong zonal flow of 10 m s 1 the integration domain was a 37 45 channel with the innermost mesh having a 22 22 point resolution of 1 6 general characteristics similar to observed landfalling tropical cyclones are obtained in the primary simulation experiment including an abrupt change in the low level 68 m winds at the coastline and a decay of the tropical cyclone at it moves inland additional interesting features subject to model and experimental limitations include little noticeable track change of the model storm when compared to a control experiment with an ocean surface only a possible temporary displacement or the center of the surface wind circulation from the surface pressure center at landfall and a distinct decrease in kinetic energy generation and precipitation a few hours after landfall the sensitivity to the specified land surface conditions was

rapidly intensifying hurricane guillermo 1997 part ii resilience in shear this paper examines the structure and evolution of a mature tropical cyclone in vertical wind shear vws using airborne doppler radar observations of hurricane guillermo 1997 in part i the modulation of eyewall convection via the rotation of vorticity asymmetries through the downshear left quadrant was documented during rapid intensification here the focus is on the relationship between vws vortex tilt and associated asymmetry within the tropical cyclone core region during two separate observation periods a method for estimating local vws and vortex tilt from radar datasets is further developed and the resulting verticalstructureanditsevolutionaresubjectedtostatisticalconfidencetests guillermowasahighlyresilient vortex evidenced by its small tilt magnitude relative to the horizontal scale of the vortex core the deep layer tilt was statistically significant oriented on average 608 left of shear large scale vorticity and thermal asymmetries oriented along the tilt direction support a response of guillermo to shear forcing that is consistent with balanced dynamics the time averaged vertical motion asymmetry within the eyewall exhibited maximum ascent values 408 left of the deep layer shear or in this case right of the deep layer tilt the observation based analysis of guillermo s interaction with vws confirms findings of recent theoretical and numerical studies and serves as the basis for a more comprehensive investigation of vws and tropical cyclone intensity change using a recently constructed multistorm database of doppler radar analyses

on the initial development of asymmetric vertical motion and horizontal relative flow in a mature tropical cyclone embedded in environmental vertical shear in this paper the authors focus on the initial development of asymmetric vertical motion and horizontal relative flow in a mature tropical cyclone tc embedded in an environmental vertical shear the fully compressible nonhydrostatic tc model was used to perform a series of numerical experiments with a mature tc with different intensities embedded in shear with different magnitudes and different vertical profiles results show that the development of both the wavenumber 1 asymmetric vertical motion and horizontal relative flow for a tc embedded in vertical shear is quite sensitive to both the magnitude and the vertical profile of wind shear as well as the intensity of the tc itself diagnostic analysis based on the quasi balanced potential vorticity inversion indicates that the balanced dynamics can only explain a small portion of the asymmetric vertical motion and relative flow the unbalanced processes contribute predominantly to the developmentoftheasymmetricflowinthesimulations itisshownthattheeyewallofamaturetcplaysarole somewhat like a material cylinder embedded in an environmental flow with vertical shear the interaction between the environmental shear and the eyewall produces vertical gradient of convergence divergence of horizontal wind around the lateral edge of the eyewall this forces much stronger asymmetric vertical motion than the balanced processes do and drives significant horizontal relative divergent flow over the storm core which opposes vertical shear and reduces the vertical tilt of the storm axis in addition the budget analysis for the axisymmetric tangential wind demonstrates that the asymmetric flow plays a dominant role in weakening the storm top down

a multiscale numerical study of hurricane andrew 1992 part ii kinematics and inner core structures despite considerable research understanding of the temporal evolution of the inner core structures of hurricanes is very limited owing to the lack of continuous high resolution observational data of a storm in this study the results of a 72 h explicit simulation of hurricane andrew 1992 with a grid size of 6 km are examined to explore the inner core axisymmetric and asymmetric structures of the storm during its rapid deepening stage based on the simulation a conceptual model of the axisymmetric structures of the storm is proposed most of the proposed structures confirm previous observations the main ingredients include a main inflow outflow in the boundary layer upper troposphere with little radial flow in between a divergent slantwise ascent in the eyewall a penetrative dry downdraft at the inner edge of the eyewall and a general weak subsiding motion in the eye with typical warming drying above an inversion located near an altitude of about 2 3 km the storm deepens as the axes of these features contract it is found that the inversion divides the eye of the hurricane vertically into two parts with a deep layer of warm dry air above and a shallow pool of warm moist air below the air aloft descends at an average rate of 5c m s 21 and has a residency time of several days in contrast the warm moist pool consists of air from the main inflow and penetrative downdrafts offset somewhat by the air streaming in a returning outflow into the eyewall in the lowest 2 km it is subject to the influence of the upward heat and moisture fluxes over the underlying warm ocean the warm moist pool appears to play an important role in supplying high ue air for deep convective development in the eyewall the penetrative downdraft is dry and originates from the return inflow in the upper troposphere and it is driven by sublimative evaporative cooling under the influence of the asymmetric radial inflow of dry cold air in the midtroposphere it penetrates to the bottom of the eye azimuthally downshear with a width often greater than 100 km in a radially narrow zone along the slantwise inner edge of the eyewall it is further shown that all the meteorological fields are highly asymmetric whereas the storm scale flow features a source sink couplet in the boundary layer and dual gyres aloft the inner core structures exhibit alternative radial inflow and outflow and a series of inhomogeneous updrafts and downdrafts all the fields tilt more or less with height radially outward and azimuthally downshear furthermore pronounced fluctuations of air motion are found in both the eye and the eyewall sometimes a deep layer of upward motion appears at the center of the eye all these features contribute to the trochoidal oscillation of the storm track and movement the main steering appears to be located at the midtroposphere 4 5 km and the deep layer mean winds represent well the movement of the hurricane

eye and eyewall traits as determined with the noaa wp 3d lower fuselage radar abstracteye and eyewall traits were ascertained for 209 images from 37 tropical cyclones tcs using the lower fuselage 5 6 cm radar aboard the two national oceanic and atmospheric administration wp 3ds these tcs were almost entirely from the atlantic basin and were sampled from 1997 to 2012 for the eye these traits included area maximum diameter and roundness for the eyewall the traits included area completeness maximum width maximum reflectivity value and location number of local reflectivity maxima and mean rain rate these variables were compared to tc intensity and motion characteristics from the best track dataset and environmental characteristics from the statistical hurricane intensity prediction scheme interrelationships between eyewall features revealed that eyewall reflectivity features became more homogeneous as eye and eyewall areas shrank and maximum reflectivity and rain rate increased as the eyewall became wider and more complete as the tc intensified the eye area decreased

the effects of vertical wind shear on the distribution of convection in tropical cyclones abstract the influence of vertical wind shear on the azimuthal distribution of cloud to ground lightning in tropical cyclones was examined using flash locations from the national lightning detection network the study covers 35 atlantic basin tropical cyclones from 1985 99 while they were over land and within 400 km of the coast over water a strong correlation was found between the azimuthal distribution of flashes and the direction of the vertical wind shear in the environment when the magnitude of the vertical shear exceeded 5 m s 1 more than 90 of flashes occurred downshear in both the storm core defined as the inner 100 km and the outer band region r 100 300 km a slight preference for downshear left occurred in the storm core and a strong preference for downshear right in the outer rainbands the results were valid both over land and water and for depression storm and hurricane stages it is argued that in convectively active tropical cyclones deep divergent circulations oppose the ver

variety of subduction and accretion processes in cretaceous to recent plate boundaries around southwest and central japan abstract the shimanto and miura boso terranes in southwest and central japan are analyzed for the understanding of variation of the subduction accretion process in convergent plate boundaries the shimanto is a cretaceous to recent honshu accretionary prism of 200 km width in the honshu arc side and is made up of melange flysch and olistostrome units these are repeated by many thrust faults and local broad and tight folds to make schuppen structures shallow marine and olistostromal bodies overlie part of the schuppen structures unconformably or are included within the structures normal subduction tectonics prevail for the formation of the accretionary prism but the effects of probable transform tectonics during late oligocene to early miocene are considerable the miura boso region is a terrane newly accreted from the izu arc to the honshu arc this terrane is made up of miocene and younger volcaniclastic sedimentary rocks dismembered ophiolitic materials and some of the rocks from the shimanto supergroup the miura boso terrane is characterized by transpressional tectonics associated with eduction during the sedimentation on the highly oblique subduction zone between the eurasia later north america and philippine sea plates several cases for the emplacement of the basaltic and other oceanic rocks to the landward side of the accretionary prism are discussed to account for the basic problem of the subduction accretion tectonics

examining polarimetric radar observations of bulk microphysical structures and their relation to vortex kinematics in hurricane arthur 2014 abstractdual polarization radar observations were taken of hurricane arthur prior to and during landfall providing needed insight into the microphysics of tropical cyclone precipitation a total of 30 h of data were composited and analyzed by annuli capturing storm features eyewall inner rainbands and outer rainbands and by azimuth relative to the deep layer environmental wind shear vector polarimetric radar variables displayed distinct signatures indicating a transition from convective to stratiform precipitation in the downshear right to downshear left quadrants which is an organization consistent with the expected kinematic asymmetry of a sheared tropical cyclone in the downshear right quadrant vertical profiles of differential reflectivity zdr and copolar correlation coefficient hv were more vertically stretched within and above the melting layer at all annuli which is attributed to convective processes an analysis of specific differential phase kdp indicated that nonspherical ice particle

some aspects of vortex structure related to tropical cyclone motion abstract some effect of tropical cyclone structure on the vortex motion are examined in a nondivergent barotropic numerical model with no basic current as suggested earlier by demaria the initial maximum wind speed has little effect on the track vortex translation associated with the beta effect depends sensitively on the strength of the flow between 300 and 1000 km from the center if the flow in this annulus is made more cyclonic the track will turn cyclonically and move more toward the west in the northern hemisphere the dynamics of this beta drift is studied via a decomposition into symmetric and asymmetric circulations the symmetric flow experiences a slight weakening of the maximum wind speed and an anticyclonic circulation is induced beyond 600 km the asymmetric circulation is dominated by an azimuthal wavenumber one circulation with an anticyclonic gyre east of the center a cyclonic gyre to the west and a nearly uniform broad scale ventilation flow between the gyres the vortex translati

a numerical study of the effect of a mountain range on a landfalling tropical cyclone abstract a triply nested movable mesh model was used to study the effects of a mountain range on a landfalling tropical cyclone embedded in an easterly flow of 10 m s 1 the integration domain consisted of a 37 wide and 45 long channel with an innermost mesh resolution of 1 6 an idealized mountain range with maximum height of 958 meters was placed parallel to the shoreline the mountain range which spanned 19 in the north south direction and 5 in the east west direction was centered in the middle of the channel results obtained were compared with a previous landfall simulation performed without the effect of the mountain range included in particular comparison was made of the total storm rainfall maximum wind distribution and storm decay rate it was found that the storm filled much more rapidly in the simulation run with the mountain included the mountain range affected the decay rate through reduction in the supply of latent and kinetic energy into the storm circulation during as well

tectonic record of convergence changes in a collision area the boso and miura peninsulas central japan abstract late cenozoic formations in boso and miura have been affected by several tectonic events tectonic analysis enables us to reconstruct six different paleostress types 1 early extension affecting the oligocene early miocene mineoka group 2 and 3 relatively minor compressional and extensional events probably early pliocene in age 4 major nne ssw compression dominating prior to 2 or 3 ma ago and 5 and 6 more recent major nnw sse compression to the west and wnw ese extension to the east both types affecting the pleistocene and prevailing since 1 2 ma ago the counterclockwise change from nne ssw to nnw sse compression is not accurately dated but very likely occurred between 2 and 3 ma ago it is compared to similar evolutions in other areas of the izu collision zone we conclude that it corresponds to a major counterclockwise change in the direction of plate convergence from sse nnw to se nw the relationships between the directions of convergence and the distributions of plio quaternary compressional paleostresses in and around the collision zone are described through a simple analogy for the two stages of plio quaternary collision this counterclockwise change in stress fields and relative motions also described in the taiwan collision zone along the same philippine sea plate eurasia boundary is interpreted as a major event at the scale of the plate the possible significances of the other paleostress types identified in boso are discussed we conclude that tectonic analysis in and along collision boundaries provides a key for understanding kinematic evolution

secondary eyewall formation and concentric eyewall replacement in association with increased low level inner core diabatic cooling abstractthe role of increased diabatic cooling in secondary eyewall formation sef and eyewall replacement cycle erc is examined using idealized numerical simulation the experiment with the low

dynamic instabilities of simulated hurricane like vortices and their impacts on the core structure of hurricanes part i dry experiments abstract a series of numerical simulations of dry axisymmetric hurricane like vortices is performed to examine the growth of barotropic and baroclinic eddies and their potential impacts on hurricane core structure and intensity the numerical experiments are performed using the fifth generation pennsylvania state university national center for atmospheric research psu ncar mesoscale model mm5 with a 6 km horizontal grid to examine internal effects on the stability of vortices all external forcings are eliminated axisymmetric vortices that resemble observed hurricane structures are constructed on an f plane and the experiments are performed without moist and boundary layer processes three vortices are designed for this study a balanced control vortex is built based on the results of a full physics simulation of hurricane floyd 1999 then two other axisymmetric vortices exp 1 and exp 2 are constructed by modifying the wind and mass fields of the control vortex the exp 1 vortex is designed t

the dynamics of the enso atlantic hurricane teleconnection enso related changes to the north african asian jet affect atlantic basin tropical cyclogenesis abstract the nature of the teleconnection linking enso variability with atlantic basin tropical storm formation is investigated solutions of the linearized barotropic vorticity equation forced with august october el nino event divergence produce upper tropospheric vorticity anomalies over the sahel and at the mouth of the north african asian naa jet over the tropical atlantic these responses are similar in magnitude and orientation to observed enso vorticity variability for this region further investigation reveals that the vorticity anomalies over the subtropical atlantic develop primarily in response to very low wavenumber westward propagating stationary rossby waves excited by el nino related convective activity over the equatorial pacific ocean however the dynamics of this teleconnection change as the atlantic basin hurricane season progresses in august and september the response is dominated by the westward propagating stationary rossby waves that alter vorticity within the naa jet and to it

dual aircraft investigation of the inner core of hurricane norbert part ii mesoscale distribution of ice particles abstract horizontal fields of cloud microphysical parameters vertical air motion and horizontal wind at the 6 km level in hurricane norbert 1984 were obtained by mapping and interpolating data collected on board a wp 3d aircraft along numerous flight tracks executed within the central region of the storm although the storm was characterized by a strong vortex of winds reaching peak values 50 m s 1 all around the storm the precipitation was concentrated on the southwest side of the storm a sloping eyewall was located within 20 to 30 km of the eye stratiform precipitation dominated the region outside the eyewall a 25 km wide band of maximum stratiform precipitation was centered 60 70 km southwest of the storm center the ice particles at flight level tended to be relatively large both in the eyewall and in the outer band of stratiform precipitation particles were smaller and more numerous 100 300 l 1 in the zone between the eyewall and outer stratiform band these particles occurred on the out

observed boundary layer wind structure and balance in the hurricane core part i hurricane georges abstract the gps dropsonde allows observations at unprecedentedly high horizontal and vertical resolution and of very high accuracy within the tropical cyclone boundary layer these data are used to document the boundary layer wind field of the core of hurricane georges 1998 when it was close to its maximum intensity the spatial variability of the boundary layer wind structure is found to agree very well with the theoretical predictions in the works of kepert and wang in particular the ratio of the near surface wind speed to that above the boundary layer is found to increase inward toward the radius of maximum winds and to be larger to the left of the track than to the right while the low level wind maximum is both more marked and at lower altitude on the left of the storm track than on the right however the expected supergradient flow in the upper boundary layer is not found with the winds being diagnosed as close to gradient balance the tropical cyclone boundary layer model of kepert and wan

structure and formation of an annular hurricane simulated in a fully compressible nonhydrostatic model tcm4 abstract the structure and formation of an annular hurricane simulated in a fully compressible nonhydrostatic tropical cyclone model tcm4 are analyzed the model is initialized with an axisymmetric vortex on an f plane in a quiescent environment and thus the transition from the nonannular hurricane to the annular hurricane is attributed to the internal dynamics the simulated annular hurricane has all characteristics of those recently documented by knaff et al from satellite observations quasi axisymmetric structure large eye and wide eyewall high intensity and suppressed major spiral rainbands a striking feature of the simulated annular hurricane is its large outward tilt of the wide eyewall which is critical to the quasi steady high intensity and is responsible for the maintenance of the large size of the eye and eyewall of the storm although the annular hurricane has a quasi axisymmetric structure marked low wavenumber asymmetries exist in the eyewall region the formation of the simulated a

quadrant dependent evolution of low level tangential wind of a tropical cyclone in the shear flow abstractthis study investigates the quadrant by quadrant evolution of the low level tangential wind near the eyewall of an idealized simulated mature tropical cyclone embedded in a unidirectional shear flow it is found that the quadrant averaged tangential wind in the right of shear quadrants weakens continuously while that in the left of shear quadrants experiences a two stage evolution a quasi steady stage followed by a weakening stage after the imposing of vertical wind shear this leads to a larger weakening rate in the right of shear and a stronger jet in the left of shear quadrants the budget analysis shows that the quadrant dependent evolution of tangential wind is controlled through the balance between the generalized coriolis force gcf i e the radial advection of absolute angular momentum and the advection terms the steady decreasing of the gcf is primarily responsible for the continuous weakening of jet strength in the right of shear quadrants for the left of shear quadrants the quas