sedimentation in a humid interior extensional basin the cenozoic li basin northern thailand facies distributions in extensional basins are controlled by a combination of factors including local and regional tectonics climate hinterland characteristics and base level changes during the mid cenozoic northern thailand was a region in which active basin formation was occurring as a result of regional extension related to major strike slip faults it was also a time when the climate was relatively humid the li basin is one of about 40 cenozoic basins in northern thailand that have a fill of continental facies and it is also one of a number of basins that contain economic coal deposits analysis of the geographical and temporal distribution of facies in the li basin indicates that it had internal drainage fed by rivers that supplied water and sediment to extensive floodplain and lake environments variations in the sediment supply were an important control on the relative development of fluvial channel and muddy overbank facies during periods of high clastic input and peat swamp and lacustrine facies when clastic input was lower changes in palaeosol type and the occurrence of peat deposits indicate that there was a trend towards drier conditions through the period of deposition of the available sections late oligocene to miocene the li basin succession provides an example of a small 500 km 2 extensional basin formed in a humid climate with interior drainage and periods of low clastic sediment supply these conditions resulted in an association of facies deposited in permanent lakes peat swamps wet and dry floodplains fluvial channels and local alluvial fans the relationships between depositional facies and tectonic climatic and sediment supply controls established in this case study may be applicable to other rift and transtensional basins

observations and models of inertial waves in the deep ocean the structure of the inertial peak in deep ocean kinetic energy spectra is studied here records were obtained from polymode arrays deployed in the western north atlantic ocean 40 w to 70 w 15 n to 42 n the results are interpreted both in terms of local sources and of turning point effects on internal waves generated at lower latitudes in most of the data there is a prominent inertial peak slightly above f however the peak height above the background continuum varies with depth and geographical environment three classes of environment and their corresponding spectra emerge from peak height variations class 1 is the 1500 m level near the mid atlantic ridge with the greatest peak height of 18 db class 2 includes a the upper ocean depth less than 2000 m b the deep ocean depth greater than 2000 m over rough topography and c the deep ocean underneath the gulf stream with intermediate peak height of 11 5 db class 3 is the deep ocean over smooth topography with the lowest peak height of 7 5 db near f the horizontal coherence scale is 0 60 km at depths from 200 m to 600 m and the vertical coherence scale is 0 200 m in the lower part of the main thermocline and 0 1000 m in the deep water the phase difference suggests a downward energy propagation in the lower thermocline and standing waves in the deep water a one turning point model is developed to describe inertial waves at mid latitudes based on the assumption that inertial waves are randomly generated at lower latitudes global generation where their frequency wave number spectrum is given by the model of garrett and munk 1972 1975 using the globally valid wave functions obtained by munk and phillips 1968 various frequency spectra near f are calculated numerically the model yields a prominent inertial peak of 7 db in the horizontal velocity spectrum but no peaks in the temperature spectrum the model is latitudinally dependent the frequency shift and bandwidth of the inertial peak decrease with latitude energy level near f is minimum at about 30 and higher at low and high latitudes the observations of class 3 can be well described by the model a low zonal wave number cutoff is required to produce the observed frequency shift of the inertial peak the differences between the global generation model and the observations of class 1 and class 2 are interpreted as the effects of local sources a locally forced model is developed based on the latitudinal modal decomposition of a localized source function asymptotic eigensolutions of laplace s tidal equation are therefore derived and used as a set of expansion functions the forcing is through a vertical velocity field specified at the top or bottom boundaries of the ocean for white noise forcing the horizontal velocity spectrum of the response has an inertial peak which diminishes in the far field with the forcing located at either the surface or the bottom several properties of the class 2 observations can be described qualitatively by a combination of the global and local models the reflection of inertial waves from a turbulent benthic boundary layer is studied by a slab model of given depth frictional effects are confined to the boundary layer and modeled by a quadratic drag law for given incident waves reflection coefficients are found to be greater than 0 9 for the long waves which contain most of the energy this result suggests that energy containing inertial waves can propagate over great distance as is required by the validity of the model of global generation

the vertical partition of oceanic horizontal kinetic energy to produce an interpretation of the surface kinetic energy as measured by altimeters a survey is made of the vertical structure of kinetic energy profiles in a large number of globally distributed long current meter records although the data are geographically confined primarily to a latitude band in the north pacific to the north atlantic and to a few moorings in the south atlantic the results show generally speaking that most regions are dominated by the barotropic and first baroclinic modes because of the near surface intensification of baroclinic modes altimeters primarily reflect the first baroclinic mode and thus the motion of the main thermocline there is good quantitative agreement with a few exceptions with estimates of the surface kinetic energy obtained from the topex poseidon altimeter and from vertical extrapolations to the surface of the mooring profiles these results are consistent with previous suggestions that barotropic models have little skill in depicting variability as seen in the altimeter data an eof analysis is shown to produce fictitious mode coupling unless the dynamical modes have very different energy levels

wavenumber spectrum in the gulf stream from shipboard adcp observations and comparison with altimetry measurements the wavenumber spectra for velocity and temperature in the gulf stream region are calculated from a decade 1994 2004 of shipboard acoustic doppler current profiler adcp measurements taken as part of the oleander project the velocity and temperature spectra have comparable magnitude in terms of the kinetic and potential energy and both indicate a k 23 slope in the mesoscales in contrast the corresponding velocity spectrum determined from satellite altimetry sea surface heights yields a significantly higher energy level and a k 22 slope the discrepancy between altimeter derived and directly measured velocity spectra suggests that altimetric velocity probably is contaminated by noise in sea surface height measurement also the k 23 slope which appears to be in agreement with two dimensional quasigeostrophic turbulence theory does not support the contemporary surface quasigeostrophic theory these results highlight large gaps in the current understanding of the nature of surface geostrophic turbulence

geochemical and petrographical characteristics of low rank balingian coal from sarawak malaysia its implications on depositional conditions and thermal maturity abstract geochemical and coal petrographical analyses were undertaken on low rank upper pliocene balingian coal from sarawak malaysia in an attempt to reconstruct the conditions during peat accumulation and the subsequent coalification processes chemically the coal in this study is characterised by high moisture low ash yield and low sulphur content the low ash yield and low sulphur content together with the lack of epiclastic partings clearly indicate that it was deposited in ombrotrophic raised bogs the coal was plotted in the type iii terrigenous kerogen zone of the van krevelen diagram with h c value below 0 9 this shows that the coal was derived from plant materials of terrigenous origin and is still immature for petroleum generation the petrographical study reveals nonetheless the expulsion of early generated hydrocarbons from the disintegration of suberinite and also from phlobaphinite and cutinite petrographically the coal is dominated by huminite with low to moderate amounts of liptinite and low amounts of inertinite pointing to predominantly anaerobic deposition conditions in the paleomires with limited thermal and oxidative tissue destruction most of the studied samples are characterised by low tpi and high gi values and are plotted on the marsh field of the diessel s diagram or it could also originate from decomposed wood in forested swamps nevertheless coals originating from both these sources usually generate high ash yield which is not the case for the studied coal this shows that the interpretation as suggested by the diessel s diagram is not valid for the studied coal the coal has a mean random huminite reflectance between 0 26 and 0 35 suggesting a lignite coal rank for the coal nevertheless geochemical classification based on total moisture and calorific value suggests a subbituminous c rank

accuracy assessment of global barotropic ocean tide models the accuracy of state of the art global barotropic tide models is assessed using bottom pressure data coastal tide gauges satellite altimetry various geodetic data on antarctic ice shelves and independent tracked satellite orbit perturbations tide models under review include empirical purely hydrodynamic forward and assimilative dynamical i e constrained by observations ten dominant tidal constituents in the diurnal semidiurnal and quarter diurnal bands are considered since the last major model comparison project in 1997 models have improved markedly especially in shallow water regions and also in the deep ocean the root sum square differences between tide observations and the best models for eight major constituents are approximately 0 9 5 0 and 6 5 cm for pelagic shelf and coastal conditions respectively large intermodel discrepancies occur in high latitudes but testing in those regions is impeded by the paucity of high quality in situ tide records long wavelength components of models tested by analyzing satellite laser ranging measurements suggest that several models are comparably accurate for use in precise orbit determination but analyses of grace intersatellite ranging data show that all models are still imperfect on basin and subbasin scales especially near antarctica for the m2 constituent errors in purely hydrodynamic models are now almost comparable to the 1980 era schwiderski empirical solution indicating marked advancement in dynamical modeling assessing model accuracy using tidal currents remains problematic owing to uncertainties in in situ current meter estimates and the inability to isolate the barotropic mode velocity tests against both acoustic tomography and current meters do confirm that assimilative models perform better than purely hydrodynamic models

geologically constrained morphological variability and boundary effects on embayed beaches abstract headlands rock outcrops and engineering structures impact beach and nearshore dynamics of coastal embayments inducing boundary effects that constrain the lateral and vertical beach variability this study analyses morphological change in six embayed beaches with diverse levels of exposure to wave action and various degrees of geological control in the mesotidal coast of southwestern portugal the aim is to identify whether geological boundaries constrain the morphological behaviour of embayed beaches and assess whether their effects can be decoupled from datasets of morphological change topographic data obtained over a two year period on each of the six embayments were analysed using empirical orthogonal functions eof to decompose temporal and spatial variability in the datasets first and second mode eigenfunctions were explored using time variable linear correlation analysis with several nearshore parameters that include hydrodynamic variables sedimentary and geometric characteristics of each embayment in order to derive forcing response relationships our results demonstrate that natural geological boundaries constrain the morphological behaviour of embayed beaches producing conspicuous alongshore variability in all embayments localised responses induced by lateral and vertical boundary interference with beach and nearshore dynamics include beach rotation topographically controlled rip circulation and restrained profile fluctuation spatial decoupling in cross and longshore responses is accompanied by a temporal decoupling in response times both of which are slower in more constrained embayments from 1 day in exposed embayments to 1 week or more in the most sheltered ones normalised wave power was correlated at the 99 confidence level with the primary mode of morphological variability at most embayments which represent 67 to 94 of the variance in the datasets this correlation stresses the importance of combined parameterization of wave and tide forcing in process response relations between hydrodynamics and morphological change for mesotidal coastal environments lateral and vertical geological boundaries exert their effects fundamentally by restraining longshore sediment transport inducing cellular surf zone circulation and by impacting cross shore sediment transport it is postulated that decreasing sediment abundance and substrate depth intensify vertical boundary effects while higher indentation and wave obliquity enhance the effects of lateral boundaries

jura cretaceous oxfordian to cenomanian stratigraphy of the north central bowser basin northern british columbia three new formations of late jurassic and early to mid cretaceous age are defined for a 2000 m thick section of jura cretaceous rocks exposed in the north central bowser basin the currier formation oxfordian to kimmeridgian or tithonian consists of 350 600 m of interbedded shales siltstones sandstones coals and carbonates the mcevoy formation barremian to as young as albian consists of 400 800 m of siltstones and shales with minor sandstones thin coals limestones and conglomerates the devils claw formation in part mid albian to cenomanian consists of 300 600 m of strata characterized by thick pebble and cobble conglomerates with associated coarse sandstones and minor siltstones and shales two successive coarsening upward sequences are identified in the study area the first begins with middle jurassic marine shales of the jackson unit grading upwards to coarser upper jurassic facies of the currier formation the currier formation is conformably or unconformably overlain by siltstones and

organic control on shoreface stacking patterns bogged down in the mire in ever wet climates raised mires that are elevated several metres above flood levels can cover significant portions of coastal plains because peat accumulation may keep pace with moderate rates of base level rise the development of raised mires may reduced the areal extent of marine transgressions thick low ash coals are present immediately landward of many vertically stacked shoreface parasequences in cretaceous state of the western interior of north america we suggest that these coals formed in raised mires that stabilized shorelines for long periods of time in such settings the rate of sediment supply including peat accumulation to the coastal environment is partly a function of the rate of change in base level

surface manifestation of internal tides in the deep ocean observations from altimetry and island gauges the sea surface height signatures of internal tides in the deep ocean amounting to a few centimeters or less are studied using two complementary measurement types satellite altimetry and island tide gauges altimetry can detect internal tides that maintain coherence with the astronomical forcing island gauges can monitor temporal variability which in some circumstances is due to internal tides varying in response to changes in the oceanic medium this latter mechanism is at work at hilo and other stations on the northern coasts of the hawaiian islands by detecting spatially coherent low frequency internal tide modulations the tide gauges along with inverted echo sounders at sea suggest that the mean internal tide is also spatially coherent satellite altimetry confirms this at hawaii and in many other places topex poseidon altimetry detects mean surface waves spatially coherent and propagating great distances 1000 km before decaying below background noise when temporal variability is small the altimetry plus information on ocean density sets useful constraints on energy fluxes into internal tides at the hawaiian ridge 15 gw of tidal power is being converted from barotropic to first mode baroclinic motion examples elsewhere warn that a simplistic interpretation of the altimetry without regard to variability noise or in situ information may be highly misleading with such uncertainties extension of the hawaiian results into a usefully realistic estimate of the global internal tide energy balance appears premature at this time

the role of mixed layer instabilities in submesoscale turbulence upper ocean turbulence at scales smaller than the mesoscale is believed to exchange surface and thermocline waters which plays an important role in both physical and biogeochemical budgets but what energizes this submesoscale turbulence remains a topic of debate two mechanisms have been proposed mesoscale driven surface frontogenesis and baroclinic mixed layer instabilities the goal here is to understand the differences between the dynamics of these two mechanisms using a simple quasi geostrophic model the essence of mesoscale driven surface frontogenesis is captured by the well known surface quasi geostrophic model which describes the sharpening of surface buoyancy gradients and the subsequent breakup in secondary roll up instabilities we formulate a similarly archetypical eady like model of submesoscale turbulence induced by mixed layer instabilities the model captures the scale and structure of this baroclinic instability in the mixed layer a wide range of scales are energized through a turbulent inverse cascade of kinetic energy that is fuelled by the submesoscale mixed layer instability major differences to mesoscale driven surface frontogenesis are that mixed layer instabilities energize the entire depth of the mixed layer and produce larger vertical velocities the distribution of energy across scales and in the vertical produced by our simple model of mixed layer instabilities compares favourably to observations of energetic wintertime submesoscale flows suggesting that it captures the leading order balanced dynamics of these flows the dynamics described here in an oceanographic context have potential applications to other geophysical fluids with layers of different stratifications

low mode internal tides and balanced dynamics disentanglement in altimetric observations synergy with surface density observations the performance of a tentative method that disentangles the contributions of a low mode internal tide on sea level from that of the balanced mesoscale eddies is examined using an idealized high resolution numerical simulation this disentanglement is essential for proper estimation from sea level of the ocean circulation related to balanced motions the method relies on an independent observation of the sea surface water density whose variations are 1 dominated by the balanced dynamics and 2 correlate with variations of potential vorticity at depth for the chosen regime of surface intensified turbulence the surface density therefore leads via potential vorticity inversion to an estimate of the balanced contribution to sea level fluctuations the difference between instantaneous sea level presumably observed with altimetry and the balanced estimate compares moderately well with the contribution from the low mode tide application to realistic configurations remains to be tested these results aim at motivating further developments of reconstruction methods of the ocean dynamics based on potential vorticity dynamics arguments in that context they are particularly relevant for the upcoming wide swath high resolution altimetric missions swot

reconstructing upper ocean vertical velocity field from sea surface height in the presence of unbalanced motion abstractreconstructability of upper ocean vertical velocity w and vorticity fields from high resolution sea surface height ssh data is explored using the global 1 48 horizontal resolution mitg

sea level changes an integrated approach sea level changes an integrated approach in october 1985 sepm sponsored a four day conference entitled sea level changes an integrated approach the purpose of the conference was to provide a forum for an interdisciplinary exchange of ideas on sea level changes and to provide an opportunity for integrating various types of evidence in approaching unresolved issues the conference was successful in bringing together scientists from industry academia and government representing all of the major geosciences disciplines presentations of many new papers plus significant releases of data that were previously held proprietary provided fertile ground for discussion this much cited volume represents the best of the material presented at the conference includes the early vail chart

m2 internal tides and their observed wavenumber spectra from satellite altimetry abstracta near global chart of surface elevations associated with the stationary m2 internal tide is empirically constructed from multimission satellite altimeter data an advantage of a strictly empirical mapping approach is that results are independent of assumptions about ocean wave dynamics and in fact can be used to test such assumptions a disadvantage is that present day altimeter coverage is only marginally adequate to support mapping such short wavelength features moreover predominantly north south ground track orientations and contamination from nontidal oceanographic variability can lead to deficiencies in mapped tides independent data from cryosphere satellite 2 cryosat 2 and other altimeters are used to test the solutions and show positive reduction in variance except in regions of large mesoscale variability the tidal fields are subjected to two dimensional wavenumber spectral analysis which allows for the construction of an empirical map of modal wavelengths mode 1 wavelengths sho

geographical variability of the first baroclinic rossby radius of deformation global 1 83 18 climatologies of the first baroclinic gravity wave phase speed c1 and the rossby radius of deformation l1 are computed from climatological average temperature and salinity profiles these new atlases are compared with previously published 5 83 58 coarse resolution maps of l1 for the northern hemisphere and the south atlantic and with a 1 83 18 fine resolution map of c1 for the tropical pacific it is concluded that the methods used in these earlier estimates yield values that are biased systematically low by 5 15 owing to seemingly minor computational errors geographical variations in the new high resolution maps of c1 and l1 are discussed in terms of a wkb approximation that elucidates the effects of earth rotation stratification and water depth on these quantities it is shown that the effects of temporal variations of the stratification can be neglected in the estimation of c1 and l1 at any particular location in the world ocean this is rationalized from consideration of the wkb approximation

beach response to a fixed sand bypassing system abstract indian river inlet is located at roughly the mid point of the atlantic coast of delaware and connects the ocean to two delaware inland bays jetties constructed in 1940 have maintained the inlet for navigation purposes but have also acted as a barrier to net northerly alongshore sediment transport causing downdrift erosion a mobile land based bypassing system was initiated in 1990 in an effort to counteract this erosion beach profile data from 1985 pre bypassing until 2008 are used to investigate the effect of the sand bypassing system on beaches adjacent to the inlet the downdrift beach experienced horizontal shoreline erosion between 10 and 60 m during the pre bypassing period but accreted 10 20 m during the bypassing period the mean shoreline location on the updrift beach during bypassing is 10 20 m landward erosion of its position during the pre bypassing period empirical orthogonal function eof amplitudes from analyses performed on mean removed elevation surfaces during the periods of highest bypassed volume average of 83 of design rate showed that the influence of the bypassing system on the downdrift beach extends to about 1500 m of the inlet an eof analysis showed that different morphologic responses were evident following the initiation of bypass operations temporal variations of shoreline and beach morphology were correlated to the temporal variations in bypassing rates on the downdrift beach only the downdrift beach response was greatest near the inlet for larger bypassing volumes correlation in these instances occurred with a roughly 1 year time lag suggesting that the beach quickly redistributes the bypassed sand eof amplitude and shoreline response are weakly correlated to bypassed volumes when the system bypassed smaller volumes average of 56 of design rate of sand suggesting that there is a minimum bypassing rate regardless of yearly variability below which the effect on the downdrift beach is obscured

global surface eddy diffusivities derived from satellite altimetry 1 velocities derived from aviso sea surface height observations adjusted to be nondivergent are used to simulate the evolution of passive tracers at the ocean surface eddy mixing rates are derived from the tracer fields in two ways first the method of nakamura is applied to a sector in the east pacific second the osborn cox diffusivity is calculated globally to yield estimates of diffusivity in two dimensions the results from the east pacific show weak meridional mixing at the surface in the southern ocean 1000 m2 s 1 consistent with previous results but higher mixing rates 3000 5000 m2 s 1 in the tropical ocean the osborn cox diagnostic provides a global picture of mixing rates and agrees reasonably well with the results from the east pacific it also shows extremely high mixing rates 104 m2 s 1 in western boundary current regions the osborn cox diffusivity is sensitive to the tracer initialization which we attribute to the presence of anisotropic mixing processes the mixing rates are strongly influenced by the presence of a mean flow nearly everywhere as shown by comparison with an eddy only calculation with the mean flow absent finally results are compared with other recent estimates of mixing rates using lagrangian and inverse methods

shoreline variability via empirical orthogonal function analysis part ii relationship to nearshore conditions the method of empirical orthogonal function eof or principal component analysis pca was used to investigate the spatial and temporal variability of shoreline data sets from duck north carolina the gold coast australia and the united states pacific northwest in the present work an attempt is made to relate the individual modes of shoreline variability identified by the eof analyses to select parameterizations of the nearshore environment the parameters considered include the wave energy e the cross shore and longshore wave energy fluxes fx and fy the wave steepness ho lo the non dimensional fall velocity parameter the profile parameter p the surf similarity parameter and a surfzone froude number fr correlation analyses were used to evaluate the linear relationship between each of these parameters and the temporal eigenfunctions ck t associated with individual modes of shoreline change typically strong correlations were observed between longshore uniform modes and the monthly means of several of the nearshore parameters

mapping the nonstationary internal tide with satellite altimetry temporal variability of the internal tide has been inferred from the 23 year long combined records of the topex poseidon jason 1 and jason 2 satellite altimeters by combining harmonic analysis with an analysis of along track wavenumber spectra of sea surface height ssh conventional harmonic analysis is first applied to estimate and remove the stationary components of the tide at each point along the reference ground tracks the wavenumber spectrum of the residual ssh is then computed and the variance in a neighborhood around the wavenumber of the mode 1 baroclinic m2 tide is interpreted as the sum of noise broadband nontidal processes and the nonstationary tide at many sites a bump in the spectrum associated with the internal tide is noted and an empirical model for the noise and nontidal processes is used to estimate the nonstationary semidiurnal tidal variance the results indicate a spatially inhomogeneous pattern of tidal variability nonstationary tides are larger than stationary tides throughout much of the equatorial pacific and indian oceans

empirical orthogonal function analysis of shoreline changes behind two different designs of detached breakwaters this paper compares the shoreline responses immediately shoreward of two adjacent schemes of segmented shore parallel rubble mound breakwaters undergoing the same forcing by waves and tides scheme one consists of four longer emergent breakwaters that have produced tidal tombolos in their lee scheme two consists of five shorter lower breakwaters that are submerged at higher tides with salients in the breakwater s lee empirical orthogonal function analysis was used to decompose a video derived shoreline dataset into the dominant modes of shoreline change for both schemes the two schemes showed similar modes of change the primary mode of change for both schemes was the cross shore growth and shrinking of the salients tombolos the secondary mode of change was the longshore movement of the salients tombolos for all modes of change the dominant length scale was dictated by the breakwater dimensions and locations a new manifestation of hydrodynamic parameters is introduced the cumulative integral of the de meaned parameters this parameterisation allowed for meaningful correlation of the temporal eof components with forcing parameters and identification of the important influence of the tide on observed morphodynamic change clear differences were observed between the shoreline responses measured in schemes one and two including differences in bay erosion accretion and the longshore translation of salients tombolos the beaches in scheme two showed behavioural patterns similar to unprotected beaches which were not observable in scheme one it is postulated that these differences are caused both by the different breakwater designs and by variation in longshore sediment supply

peat accumulating depositional systems of sarawak east malaysia many coal deposits originate in deltaic estuarine and coastal plain settings and a knowledge of interrelationships between the tectonic and depositional elements active at the time of sediment deposition is necessary to formulate basin scale models the prograding coastal depositional systems of sarawak all contain domed peat accumulating environments in which low ash low sulfur peats are being deposited in areas of active clastic siliciclastic sedimentation these depositional systems are as large as 11 400 km2 and individual peat deposits within systems are in excess of 20 m thick and 1000 km2 in area the geographic positions and drainage basin areas of each depositional system are controlled by fault and fold systems although prograding into the same receiving basin individual system geomorphology is variable and ranges from a wave dominated microtidal delta to a wave dominated meso to macro tidal delta coastal plain system to a tide dominated macrotidal estuarine embayment along a 450 km stretch of coastline system variation is a function of sediment supply shelf and embayment geometry wave climate and tidal range these factors which control depositional system geomorphology also control the resulting long axis orientation of the thick domed peat deposits the surface vegetation and internal characteristics of most domed peat deposits however are similar internal characteristics consist of basal high ash high sulfur degraded peats overlain by low ash low sulfur well preserved peats in vertical profile these systems demonstrate variable responses to late pleistocene holocene sea level rise and in these instances the variation is most attributable to local differences in siliciclastic sediment supply which is a function of the drainage basin area

the age palaeoclimate palaeovegetation coal seam architecture mire types paleodepositional environments and thermal maturity of syn collision paralic coal from mukah sarawak malaysia abstract the mukah coal accumulated in the balingian formation where the time stratigraphic position is poorly defined by fauna though a probable late miocene age has always been assigned to this formation samples collected in the present study that yielded an abundance of casuarina pollen associated with occurrences of dacrydium stenochlaena palustris florschuetzia levipoli and also stenochlaena areolaris spores compare closely to zone pr9 of the palynological zonation of the malay basin and can be tied to depositional sequences of malay basin seismic sequences i2000 i3000 indicating an early miocene age for the studied coal the early miocene age shows that the mukah coal was formed during the collision between luconia block dangerous grounds with the borneo that lasted from late eocene to late early miocene the rapid increase of deposition base level caused by the collision is clearly reflected by the architecture of the mukah coal seams that were generally thin and also by the reverse order of the paleo peat bodies the studied coal samples contained large amounts of detrohuminite without the enrichment of liptinite group macerals usually explained by the dominance of herbaceous plants in the paleomires however the pollen assemblages recovered in the present study provide no support for a herbaceous swamp instead the peats were likely formed mainly from forest vegetation based on the recovery of dominant arboreal pollen assemblages in the present study palynomorph assemblages recovered in the present study with abundance of casuarina pollen associated with common occurrences of dacrydium strongly suggest kerangas vegetation and kerapah type peat swamps indicating a very wet climate the occurrence of rattan and pandanus pollens shows that the kerapah type peat swamps were locally bordered by rattan and pandanus swamps this shows that the prevailing use of coal petrography to discern the type of vegetation that was present in the peat forming mires may lead to wrong conclusions therefore a multi disciplinary approach must be applied for a more accurate and reliable spatial interpretation of the type of vegetation that was present in the peat forming mires consistent with the low sulphur content evidence from the palynomorph assemblages recovered from the coal seams shows that the coal forming peat was deposited in freshwater mires with little or no marine influence despite the fact that the accumulation of the mukah coal forming peat took place within a coastal plain setting moreover the fauna present in the host rock formation also suggested a brackish water environment of deposition

interpreting energy and tracer spectra of upper ocean turbulence in the submesoscale range 1 200 km submesoscale 1 200km wavenumber spectra of kinetic and potential energy and tracer variance are obtained from in situ observations in the gulf stream region and in the eastern subtropical north pacific in the gulf stream region steep kinetic energy spectra at scales between 200 and 20km are consistent with predictions of interior quasigeostrophic turbulence theory both in the mixed layer and in the thermocline at scales below 20km the spectra flatten out consistent with a growing contribution of internal wave energy at small scales in the subtropical north pacific theenergyspectraareflatterand inconsistentwith predictionsofinteriorquasigeostrophic turbulence theory the observed spectra and their dependence on depth are also inconsistent with predictions of surface quasigeostrophic turbulencetheoryfortheobservedoceanstratification itappearsthatunbalancedmotions most likely internal tides at large scales and the internal wave continuum at small scales dominate the energy spectrum throughout the submesoscale range spectra of temperature variance along density surfaces which are not affected by internal tides are also inconsistent with predictions of geostrophic turbulence theories reasons for this inconsistency could be the injection of energy in the submesoscale range by small scale baroclinic instabilities or modifications of the spectra by coupling between surface and interior dynamics or by ageostrophic frontal effects

global baroclinic tides an approximate estimate of the energy in the first mode m2 baroclinic tide has been made from satellite observations results based on topex poseidon t p precision altimetry indicate that the internal tide patterns are similar to those expected from mid ocean topographic features in the global oceans both the orthotide and harmonic analyses indicate that the total energy in global m2 baroclinic tide is approximately 50 pj for a variety of reasons m2 is the only component that can be obtained reliably from altimetric measurements even then the energy value may be an underestimate and the energy flux the dissipation rate cannot be deduced from altimetry since it is the tidal currents flowing over mid ocean topographic features that are responsible for generating internal tides a model calibrated by m2 observations is a plausible alternative currents from a high resolution 15 barotropic tidal model have therefore been used to obtain an estimate of both the energy and the dissipation rate in m2 s2 and k1 baroclinic tides a simple model of baroclinic tide generation has been used and the unknown constant in this model has been selected to yield a total energy of 50 pj in the first mode m2 baroclinic tide based on this calibration the total energy is 8 pj in s2 first mode baroclinic tide and 15 pj in k1 the total in all first mode baroclinic tides is 90 pj about 16 of the total energy 580 pj in barotropic tides the model results also suggest that about 360 gw of tidal energy are dissipated in m2 baroclinic tides alone and 520 gw are dissipated in all first mode baroclinic tides the latter value is approximately 15 of the power input into barotropic ocean tides 3490 gw by the lunisolar tidal forces we have preferred to be conservative and hence these are likely to be underestimates especially since the altimetric tracks do not often intersect mid ocean topographic features at optimum angles while these values are very much within the range of earlier estimates in literature they should be regarded as still uncertain to perhaps a factor of two the dissipation rate could be anywhere from 400 gw to 800 gw the most likely value being about 600 gw the small signal to noise ratio involved in altimetric measurements of the surface manifestation of internal tides and potential contamination by mesoscale signals are serious problems in situ measurements at least a few locations underneath altimetric tracks are essential for confirmation and or refinement of these preliminary estimates hopefully these very first estimates of the energy and dissipation rate in global baroclinic tides though rather crude will serve as a catalyst for a better estimation in the future since internal tides are likely to be a prominent source of mixing in the deep oceans and important to thermocline maintenance

can oceanic submesoscale processes be observed with satellite altimetry high resolution 2 km and hourly observations of surface currents from high frequency radars are analyzed in terms of sea level anomalies sla and compared with data from two satellite altimeter ground tracks purpose is to investigate whether ocean submesoscale processes can be observed with satellite altimetry our results highlight two major problems that must be overcome before being able to resolve submesoscale processes with altimetry i signal contamination from high frequency motions and in particular from incoherent internal tides near inertial oscillations have no effect on sla and ii measurement noise which prevents the computation of accurate cross track currents on scales o 10 km the latter may be overcome by future satellite altimeter missions but the former will require taking into account the effect of mesoscale variability on internal tide propagation in regions where internal tides are significant citation chavanne c p and p klein 2010 can oceanic submesoscale processes be observed with satellite altimetry geophys res lett 37 l22602 doi 10 1029 2010gl045057

beach morphologies induced by breakwaters with different orientations abstract a desired outcome in the construction of a detached emerged breakwater is the formation of an accretionary salient in its lee to augment the beach improve beach amenity and provide an additional buffer from storm waves the extent to which this salient forms and its morphology are strongly controlled by the breakwater geometry with respect to the original shoreline sediment availability and local wave climate the purpose of this paper is to identify how breakwater geometry and orientation of gaps between individual breakwaters alter the direction of waves entering the gaps and change the asymmetry of the salients four distinct breakwater sites along the emilia romagna coastline in northern italy were chosen for a detailed field and desktop study comprising three dimensional topographic and bathymetric surveys sediment sampling lidar flights and historical shoreline mapping the orientations of the shorelines at these four sites range over 43 resulting in different exposures to the dominant waves the oblique orientations of the gaps between individual breakwater segments at three of the four sites effectively create a gap window between breakwaters favoring the exposure of short period waves from the north and diminishing the effect of longer waves from the dominant east salients can be symmetrical despite an acute angle of approach of the dominant deep water waves where refraction is enhanced by offshore topography and breakwaters are parallel to the shore waves approaching normal to the gap window undergo less diffraction due to their shorter length relative to the gap window width and undergo less attenuation by breaking and bottom friction if they are locally generated and have short periods greater breaking wave energy on the gap facing slope of the salient can create shoreline and morphological asymmetry the implication is that breakwater orientations can be designed or altered to selectively dampen or facilitate wave energy to enhance sediment transport in a desired direction provided that breakwaters are not too far offshore and sediment availability is not restricted to affect salient formation adjusting exposure via gap orientation can create morphologies that cannot be inferred from process dominant conditions

global observations of open ocean mode 1 m2internal tides abstracta global map of open ocean mode 1 m2 internal tides is constructed using sea surface height ssh measurements from multiple satellite altimeters during 1992 2012 representing a 20 yr coherent internal tide field a two dimensional plane wave fit method is employed to 1 suppress mesoscale contamination by extracting internal tides with both spatial and temporal coherence and 2 separately resolve multiple internal tidal waves global maps of amplitude phase energy and flux of mode 1 m2 internal tides are presented the m2 internal tides are mainly generated over topographic features including continental slopes midocean ridges and seamounts internal tidal beams of 100 300 km width are observed to propagate hundreds to thousands of kilometers multiwave interference of some degree is widespread because of the m2 internal tide s numerous generation sites and long range propagation the m2 internal tide propagates across the critical latitudes for parametric subharmonic instability 28 8 s n

transgressive regressive cycles and the occurrence of coal in some upper cretaceous strata of utah cenomanian santonian strata contain about 60 of the known cretaceous coal resources of utah the areal and temporal distribution of these resources can be related to the transgressive regressive history of the western shoreline of the interior cretaceous seaway two orders of transgressive regressive cycles the larger of which corresponds to third order cycles of vail et al are deemed important in analyzing the distribution of coal in utah the largest coal fields are associated with extensive vertical stacking of the deposits of what are here termed fourth order cycles at the transgressive and regressive maxima of third order cycles deposits of transgressive and regressive phases of third order cycles contain only minor amounts of coal this genetic relationship may prove useful in predicting areas of important cretaceous coal resources in deeper parts of structural basins in the rocky mountain region

seasonality in transition scale from balanced to unbalanced motions in the world ocean abstractthe transition scale lt from balanced geostrophic motions to unbalanced wave motions including near inertial flows internal tides and inertia gravity wave continuum is explored using the output from a global 1 48 horizontal resolution massachusetts institute of technology general circulation model mitgcm simulation defined as the wavelength with equal balanced and unbalanced motion kinetic energy ke spectral density lt is detected to be geographically highly inhomogeneous it falls below 40 km in the western boundary current and antarctic circumpolar current regions increases to 40 100 km in the interior subtropical and subpolar gyres and exceeds in general 200 km in the tropical oceans with the exception of the pacific and indian sectors of the southern ocean the seasonal ke fluctuations of the surface balanced and unbalanced motions are out of phase because of the occurrence of mixed layer instability in winter and trapping of unbalanced motion ke in shallow mixed layer in summe

estimates and implications of surface eddy diffusivity in the southern ocean derived from tracer transport abstract near surface effective diffusivities associated with geostrophic eddies in the southern ocean are estimated by numerically monitoring the lengthening of idealized tracer contours as they are strained by surface geostrophic flow observed by satellite altimetry the resulting surface diffusivities show considerable spatial variability and are large 2000 m2 s 1 on the equatorward flank of the antarctic circumpolar current and are small 500 m2 s 1 at the jet axis regions of high and low effective diffusivity are shown to be collocated with regions of respectively weak and strong isentropic potential vorticity gradients the maps of diffusivity are used along with climatological estimates of surface wind stress and air sea buoyancy flux to estimate surface meridional residual flows and the relative importance of eulerian and eddy induced circulation in the streamwise averaged dynamics of the antarctic circumpolar current

ocean science eddy effects on biogeochemistry ocean eddies tens of kilometres in radius can delineate local ecosystems and contribute to biogeochemical budgets the characterization of three such eddies in a coastal upwelling region provides insight into these wonders of nature

open ocean submesoscale motions a full seasonal cycle of mixed layer instabilities from gliders abstractthe importance of submesoscale instabilities particularly mixed layer baroclinic instability and symmetric instability on upper ocean mixing and energetics is well documented in regions of strong persistent fronts such as the kuroshio and the gulf stream less attention has been devoted to studying submesoscale flows in the open ocean far from long term mean geostrophic fronts characteristic of a large proportion of the global ocean this study presents a year long submesoscale resolving time series of near surface buoyancy gradients potential vorticity and instability characteristics collected by ocean gliders that provides insight into open ocean submesoscale dynamics over a full annual cycle the gliders continuously sampled a 225 km2 region in the subtropical northeast atlantic measuring temperature salinity and pressure along 292 short 20 km hydrographic sections glider observations show a seasonal cycle in near surface stratification throughout the fall september november

semi diurnal and diurnal tidal dissipation from topex poseidon altimetry 1 tidal energy dissipation is estimated for eight semi diurnal and diurnal constituents using a global inverse solution constrained by topex poseidon altimeter data very similar spatial patterns are obtained for all semi diurnal constituents with about one third of the total dissipation occurring in the deep ocean over rough topography maps for diurnal constituents are also similar amongst themselves but quite different from the semi diurnal results for diurnals a smaller fraction of dissipation roughly 10 occurs in the deep ocean much of the difference can be explained by the very different spatial pattern of diurnal and semi diurnal tidal currents the lack of free internal waves at frequencies poleward of 30 at diurnal frequencies also probably plays a role limiting the effectiveness of baroclinic conversion as an energy sink for barotropic diurnal tides

satellite altimetry the marine geoid and the oceanic general circulation for technical reasons the general circulation of the ocean has historically been treated as a steady laminar flow field the recent availability of extremely highaccuracy and high precision satellite altimetry has provided a graphic demonstration that the ocean is actually a rapidly time evolving turbulent flow field to render the observations quantitatively useful for oceanographic purposes has required order of magnitude improvements in a number of fields including orbit dynamics gravity field estimation and atmospheric variability with five years of very high quality data now available the nature of oceanic variability on all space and time scales is emerging including new findings about such diverse and important phenomena as mixing coefficients the frequency wavenumber spectrum and turbulent cascades because the surface elevation is both a cause and consequence of motions deep within the water column oceanographers soon will be able to provide general circulation numerical models tested against and then combined with the altimeter data these will be complete three dimensional timeevolving estimates of the ocean circulation permitting greatly improved estimates of oceanic heat carbon and other property fluxes

mixed layer instabilities and restratification abstract the restratification of the oceanic surface mixed layer that results from lateral gradients in the surface density field is studied the lateral gradients are shown to be unstable to ageostrophic baroclinic instabilities and slump from the horizontal to the vertical these instabilities which are referred to as mixed layer instabilities mlis differ from instabilities in the ocean interior because of the weak surface stratification spatial scales are o 1 10 km and growth time scales are on the order of a day linear stability analysis and fully nonlinear simulations are used to study mlis and their impact on mixed layer restratification the main result is that mlis are a leading order process in the ml heat budget acting to constantly restratify the surface ocean climate and regional ocean models do not resolve the scales associated with mlis and are likely to underestimate the rate of ml restratification and consequently suffer from a bias in sea surface temperatures and ml depths in a

wavenumber frequency analysis of landslide generated tsunamis at a conical island part ii eof and modal analysis abstract in this paper the empirical orthogonal function eof method is applied to extract from the experimental data related to landslide tsunamis around the coast of a conical island the spatial modes that contribute to the wave field for each mode the wavenumber and the frequency are calculated by analyzing the shape along the coast and the time function the relevant modes are then compared with those obtained through numerical eigenanalysis of the long wave equation around the considered island it was possible to associate each eof mode with some eigenvectors and the corresponding eigenfrequencies both on the basis of the spatial shape the wavenumber calculated along the coast and the frequency results confirm that landslide generated waves propagate along the coast as trapped edge waves and the zero th order mode is the most important further of exploring the physics it is believed that this paper can be of use as some of the most relevant and straightforward techniques for modal identification are applied to the same problem and dataset

wave set up on a natural beach wave set up the superelevation of mean water level owing to the presence of breaking incident waves was measured at the shoreline of a natural beach offshore pressure sensors monitored incident wave conditions the set up of the shoreline was found to be about 0 17hs where hs is the significant wave height in deep water

resonant diurnal internal tides in the north atlantic using a large acoustical array located midway between puerto rico and bermuda we have observed enhanced diurnal tidal signals associated with the lowest internal wave mode these signals result from a diurnal internal wave resonantly trapped between the shelf just north of puerto rico and the turning latitude a distance of about 1100 km the data obtained using the large acoustical array are consistent with the predicted airy function variation with latitude of diurnal internal waves near the turning latitude the existence of this wave is a striking demonstration of the long spatial and temporal coherence of oceanic internal tides in general the energy radiated by such waves is a loss of energy from the earth moon system and a source of energy for mixing in the deep ocean

natural variability of shoreline position observations at three pocket beaches we investigated the variability of shoreline position of three adjacent pocket beaches at barcelona city nw mediterranean over a period of two years daily measurements of shoreline position were extracted from high resolution video images and used to determine shoreline variability using empirical orthogonal function analysis we determine two dominant modes of shoreline variability for all beaches analysed the mode that explains most of the variability around 70 describes the beach plan form rotation which primarily occurs at the seasonal scale the cross shore translation of the beach profile is described by the 2nd mode which explains around 30 both types of shoreline movement have been related to the previous nearshore conditions this relationship was explored standardizing the translation rotation of the shoreline and comparing it with time averages of the cross shore energy flux efcsh and the energy flux direction efd averages over 7 to 12 days of efcsh were significantly correlated to the translation movement plan form rotation was well described by 28 to 40 day averaging of efd comparing results from the three beaches we determined that the time required to average the previous wave conditions depends on the beach characteristics beach length and sediment grain size in such a way that the greater the length of the beach and its sediment grain size the slower its response

significance of jurassic radiolarians from the cache creek terrane british columbia the discovery of new radiolarian localities in the western belt of the cache creek terrane in southern british columbia possibly changes its upper age limit from late triassic to early or middle jurassic it favors a middle jurassic rather than a late triassic age of amalgamation for the cache creek terrane and quesnellia parts of superterrane i in southern british columbia the new jurassic ages also mean that the western cache creek terrane could be equivalent in age to the bridge river hozameen terrane in british columbia and to terranes containing the tethyan fusulinid yabeina in northwest washington and the klamath mountains of california

non stationary internal tides observed with satellite altimetry 1 temporal variability of the internal tide is inferred from a 17 year combined record of topex poseidon and jason satellite altimeters a global sampling of along track sea surface height wavenumber spectra finds that non stationary variance is generally 25 or less of the average variance at wavenumbers characteristic of mode 1 tidal internal waves with some exceptions the non stationary variance does not exceed 0 25 cm2 the mode 2 signal where detectable contains a larger fraction of non stationary variance typically 50 or more temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3 year records comparison of summer vs winter conditions shows only one region of noteworthy seasonal changes the northern south china sea implications for the anticipated swot altimeter mission are briefly discussed

the accuracy of surface elevations in forward global barotropic and baroclinic tide models abstract this paper examines the accuracy of surface elevations in a forward global numerical model of 10 tidal constituents both one layer and two layer simulations are performed as far as the authors are aware the two layer simulations and the simulations in a companion paper deep sea research ii 51 2004 3043 represent the first published global numerical solutions for baroclinic tides self consistent forward solutions for the global tide are achieved with a convergent iteration procedure for the self attraction and loading term energies are too large and elevation accuracies are poor unless substantial abyssal drag is present reasonably accurate tidal elevations can be obtained with a spatially uniform bulk drag c d or horizontal viscosity k h but only if these are inordinately large more plausible schemes concentrate drag over rough topography the topographic drag scheme used here is based on an exact analytical solution for arbitrary small amplitude terrain and supplemented by dimensional analysis to account for drag due to flow splitting and low level turbulence as well as that due to breaking of radiating waves the scheme is augmented by a multiplicative factor tuned to minimize elevation discrepancies with respect to the topex poseidon t p constrained got99 2 model the multiplicative factor may account for undersampled small spatial scales in bathymetric datasets an optimally tuned multi constituent one layer simulation has an rms elevation discrepancy of 9 54 cm with respect to got99 2 in waters deeper than 1000 m and over latitudes covered by t p 66 n to 66 s the surface elevation discrepancy decreases to 8 90 cm 92 percent of the height variance captured in the optimally tuned two layer solution the improvement in accuracy is not due to the direct surface elevation signature of internal tides which is of small amplitude but to a shift in the barotropic tide induced by baroclinicity elevations are also more accurate in the two layer model when pelagic tide gauges are used as the benchmark and when the t p constrained tpxo6 2 model is used as a benchmark in deep waters south of 66 s for antarctic diurnal tides the improvement in forward model elevation accuracy with baroclinicity is substantial the optimal multiplicative factor in the two layer case is nearly the same as in the one layer case against initial expectations that the explicit resolution of low mode conversion would allow less parameterized drag in the optimally tuned two layer m 2 solution local values of the ratio of temporally averaged squared upper layer speed to squared lower layer speed often exceed 10

variation in subaerial beach sediment volume on a small sandy beach over a monthly lunar tidal cycle abstract three major patterns of sediment movement along 0 5 m deep horizontal segments of beachface on a small sandy beach at coledale new south wales were determined by empirical orthogonal function eof analysis of a 36 day record of beach change the fundamental beach response is identified by the first eigenfunction mode the mode describes sediment transfers occurring over the beachface between the low tide zone and the berm crest as well as sediment movement along the beach the alongshore translocations occurred about a nodal point located approximately 0 75 of distance along the beach from its southern end transfers across the beach were established by comparing the time series associated with the eigenfunctions describing alongshore transfers of sediment in different segments the slice to slice comparisons showed an increasing phase down the beachface from the berm crest segment to the mid tidal zone the phase difference was approximately 2 5 days per 0 5 m segment the fundamental beach response and secondary sediment transfers typical of the supratidal zone occur with an apparent 28 30 day lunar tide cycle they were unrelated to short term variations in the incident wave amplitude lower down the beachface the time series associated with the eigenfunction describing sediment translocations in the mid tidal zone is aperiodic the irregularities can be linked to particular process events however similar beach changes were not always related to similar process conditions and they were not simply related to wave regime fluctuations the patterns of sediment movement along coledale beach were consistent with similar patterns reported from elsewhere by clarke and eliot 1982 1983a in that they were closely related to variation in the nearshore water circulation system in particular nodal points identified by the eof analysis commonly occurred on the beachface landward of inshore regions where bars most frequently developed the antinodal positions were similarly associated with regions where rip channels are frequently formed

decadal scale impacts of a segmented shore parallel breakwater system abstract between 1994 and 1997 nine segmented shore parallel rock mound breakwaters were constructed at the meso tidal beach of sea palling on the north sea coast of the uk to provide protection for a low lying hinterland vulnerable to storm surge inundation and a 3 5 km section of sea wall that was in danger of collapse due to low beach levels in this paper we assess the effectiveness of these breakwaters and of the associated beach recharge events in stabilising the beaches both within and around the breakwater system and we examine their impact on the wider littoral drift system we discuss a trapping mechanism whereby sand entering the system as littoral drift is effectively retained at both ends of the system at the northern updrift end the trapping of littoral drift sediments aided by a 1 3 106 m3 sediment recharge designed to remedy severe gap erosion lead to the growth of salients into tidal tombolos effectively changing the x h ratio distance offshore depth on pope and dean s 1986 morphology existence diagram the largest tombolo tombolo 5 is at the updrift end is only inundated during large storm surges and forms a 260 m wide barrier to littoral drift and the alongshore supply of sediment to breakwater beaches in response to a large reduction in littoral drift shorelines in the centre of the system are steadily retreating with some embayment shorelines being closer to the seawall in 2005 than they were pre construction these shorelines have not reached a steady state and further recharge will be needed unless the littoral drift supply can be restored the evidence nearshore morphology sediment starved beaches down drift recharge shoreline change patterns and a simple sediment budget indicates that an estimated 80 of littoral drift sediments are directed offshore at tombolo 5 bypass the breakwaters and downdrift beaches but may return to shore 2 5 km downdrift as a direct result of recharge sea palling makes a less than ideal case for assessing the applicability of micro tidal shoreline response equations to breakwaters in tidal settings the sea palling experience also demonstrates that the use of beach recharge in combination with breakwaters in settings of high littoral drift requires very careful consideration as it has the potential to block littoral drift and starve the local beaches the opposite effect of that intended by both techniques

mesoscale to submesoscale transition in the california current system part i flow structure eddy flux and observational tests in computational simulations of an idealized subtropical eastern boundary upwelling current system similar to the california current a submesoscale transition occurs in the eddy variability as the horizontal grid scale is reduced to o 1 km this first paper in a series of three describes the transition in terms of the emergent flow structure and the associated time averaged eddy fluxes in addition to the mesoscale eddies that arise from a primary instability of the alongshore wind driven currents significant energy is transferred into submesoscale fronts and vortices in the upper ocean the submesoscale arises through surface frontogenesis growing off upwelled cold filaments that are pulled offshore and strained in between the mesoscale eddy centers in turn some submesoscale fronts become unstable and develop submesoscale meanders and fragment into roll up vortices associated with this phenomenon are a large vertical vorticity and rossby number a large vertical velocity relatively flat horizontal spectra contrary to the prevailing view of mesoscale dynamics a large vertical buoyancy flux acting to restratify the upper ocean a submesoscale energy conversion from potential to kinetic a significant spatial and temporal intermittency in the upper ocean and material exchanges between the surface boundary layer and pycnocline comparison with available observations indicates that submesoscale fronts and instabilities occur widely in the upper ocean with characteristics similar to the simulations

shoreline variability via empirical orthogonal function analysis part i temporal and spatial characteristics empirical orthogonal functions eofs or principal components were used to extract the significant modes of shoreline variability from several data sets collected at three very different locations although eofs have proven to be a valuable tool in the analysis of nearshore data most applications have focused on the ability of the technique to describe cross shore or profile variability here however eofs were used to help identify the dominant modes of longshore shoreline variability at duck north carolina the gold coast australia and at several locations within the columbia river littoral cell in the u s pacific northwest in part one of this analysis characteristic patterns of shoreline variability identified by the eof analysis are described in detail at each site the dominant modes consisting of the first four eigenfunctions were found to describe nearly 95 of the total shoreline variability at both duck and the gold coast several interesting longshore periodic features suggestive of sand waves were identified while boundary effects related to natural headlands and navigational structures entrances dominated the pacific northwest data sets

ssh wavenumber spectra in the north pacific from a high resolution realistic simulation abstractfollowing recent studies based on altimetric data this paper analyses the spectral characteristics of the sea surface height ssh using a new realistic simulation of the north pacific ocean with high resolution in the horizontal and 100 vertical levels this simulation resolves smaller scales down to 10 km than altimetric data limited to 70 km because of the noise level in high eddy kinetic energy eke regions as in the western part ssh spectral slope almost follows a k 4 with k the wavenumber or slightly steeper law in agreement with altimeter studies the new result is that unlike altimeter studies such a k 4 slope is also observed in low eke regions as in the eastern part in these regions this slope mostly concerns scales not well resolved by altimetric data such k 4 ssh spectral slopes are weaker from what is expected from quasigeostrophic turbulence theory but closer to surface quasigeostrophic sqg turbulence theory the consequence is that the small scales concerned

a frontal challenge for climate models the ocean surface is filled with a convoluted web of fronts that separate waters of different temperatures and salinities see the figure just as thin ducts in the lung called alveoli facilitate the rapid exchange of gases when breathing fronts are the ducts through which heat carbon oxygen and other climatically important gases enter into the deep ocean a lack of observations however has hampered progress in understanding the dynamics of fronts which can be as narrow as hundreds of meters and as wide as tens of kilometers global satellite measurements of ocean surface velocities and air sea fluxes for instance are only available at resolutions of a few hundred kilometers although shipboard researchers can sample vertical ocean profiles down to centimeter scales only rarely do they collect profiles that are less than 100 km apart on page 318 of this issue d asaro et al 1 present a breakthrough in observing ocean fronts providing direct observations of the workings of the kuroshio front off japan on scales from kilometers to millimeters this detailed and wide ranging portrait was made possible by the development of towed instruments that continuously sample the waters behind a steaming ship the deployment of freely drifting instruments that follow ocean currents and the exercising of a great deal of ingenuity in keeping all these tools along the front for a few weeks in 2007

significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data how and where the ocean tides dissipate their energy are long standing questions1 that have consequences ranging from the history of the moon2 to the mixing of the oceans3 historically the principal sink of tidal energy has been thought to be bottom friction in shallow seas4 5 there has long been suggestive evidence6 7 however that tidal dissipation also occurs in the open ocean through the scattering by ocean bottom topography of surface tides into internal waves but estimates of the magnitude of this possible sink have varied widely3 8 9 10 11 here we use satellite altimeter data from topex poseidon to map empirically the tidal energy dissipation we show that approximately 1012 watts that is 1 tw representing 25 30 of the total dissipation occurs in the deep ocean generally near areas of rough topography of the estimated 2 tw of mixing energy required to maintain the large scale thermohaline circulation of the ocean12 one half could therefore be provided by the tides with the other half coming from action13 on the surface of the ocean

parameterization of mixed layer eddies part ii prognosis and impact abstract the authors propose a parameterization for restratification by mixed layer eddies that develop from baroclinic instabilities of ocean fronts the parameterization is cast as an overturning streamfunction that is proportional to the product of horizontal buoyancy gradient mixed layer depth and inertial period the parameterization has remarkable skill for an extremely wide range of mixed layer depths rotation rates and vertical and horizontal stratifications in this paper a coarse resolution prognostic model of the parameterization is compared with submesoscale mixed layer eddy resolving simulations the parameterization proves accurate in predicting changes to the buoyancy the climate implications of the proposed parameterization are estimated by applying the restratification scaling to observations the mixed layer depth is estimated from climatology and the buoyancy gradients are from satellite altimetry the vertical fluxes are comparable to monthly mean air sea fluxes in large areas of

propagation of low mode internal waves through the ocean abstract the baroclinic tides play a significant role in the energy budget of the abyssal ocean although the basic principles of generation and propagation are known a clear understanding of these phenomena in the complex ocean environment is only now emerging to advance this effort a ray model is developed that quantifies the effects of spatially variable topography stratification and planetary vorticity on the horizontal propagation of internal gravity modes the objective is to identify baroclinic shoals where wave energy is spatially concentrated and enhanced dissipation might be expected the model is then extended to investigate the propagation of internal waves through a barotropic mesoscale current field the refraction of tidally generated internal waves at the hawaiian ridge is examined using an ensemble of mesoscale background realizations derived from weekly ocean topography experiment topex poseidon altimetric measurements the path of mode 1 is only slightly affected by typical cur

some expectations for submesoscale sea surface height variance spectra abstractin anticipation of the surface water and ocean topography swot wide swath altimetry mission this study reviews expectations for sea surface height ssh variance spectra at wavelengths o

spectral decomposition of internal gravity wave sea surface height in global models two global ocean models ranging in horizontal resolution from 1 12 to 1 48 are used to study the space and time scales of sea surface height ssh signals associated with internal gravity waves igws frequency horizontal wavenumber ssh spectral densities are computed over seven regions of the world ocean from three simulations of the hybrid coordinate ocean model hycom and two simulations of the massachusetts institute of technology general circulation model mitgcm high wavenumber high frequency ssh variance follows the predicted igw linear dispersion curves the realism of high frequency motions 0 87cpd in the models is tested through comparison of the frequency spectral density of dynamic height variance computed from the highest resolution runs of each model 1 25 hycom and 1 48 mitgcm with dynamic height variance frequency spectral density computed from 9 in situ profiling instruments these high frequency motions are of particular interest because of their contributions to the small scale ssh variability that will be observed on a global scale in the upcoming surface water and ocean topography swot satellite altimetry mission the variance at supertidal frequencies can be comparable to the tidal and low frequency variance for high wavenumbers length scales smaller than 50km especially in the higher resolution simulations in the highest resolution simulations the high frequency variance can be greater than the low frequency variance at these scales

inferring dynamics from the wavenumber spectra of an eddying global ocean model with embedded tides 1 the slopes of the wavenumber spectra of sea surface height ssh and kinetic energy ke have been used to infer interior or surface quasi geostrophic qg or sqg dynamics of the ocean however inspection of spectral slopes for altimeter ssh in the mesoscale band of 70 to 250 km shows much flatter slopes than the qg or sqg predictions over most of the ocean comparison of altimeter wavenumber spectra with spectra from an eddy resolving global ocean circulation model the hybrid coordinate ocean model hycom at 1 12 5 equatorial resolution which has embedded tides suggests that the flatter slopes of the altimeter ssh may arise from three possible sources 1 presence of strong internal tides 2 shift of the inertial sub range to smaller scales and 3 altimeter noise artificially adding noise to the model tends to flatten the spectra for low ke regions near internal tide generating regions spectral slopes in the presence of internal waves are much flatter than qg or sqg predictions separating the variability into high and low frequency around periods of 2 days then a different pattern emerges with a flat high frequency wavenumber spectrum and a steeper low frequency wavenumber spectrum for low mesoscale ke the inertial sub range defined by the nearly flat enstrophy band moves to smaller scales and the mesoscale band of 70 to 250 km no longer represents the inertial sub range the model wavenumber spectra are consistent with qg and sqg theory when internal waves and inertial sub range shifts are taken into consideration

coals associated with tidal sediments in the wilcox group paleogene south texas abstract the several coal seams in 50 m of wilcox strata on the chacon creek east lignite property in south texas are closely associated with tidal sediments the coal bearing sequence is underlain by greenish bioturbated sandstone deposited in open marine water the sediments between the coals and cutting the coals consist of coarsening and fining upward sequences of interbedded sandstone and mudstone with lenticular wavy and flaser bedding and ripple laminated and cross bedded sandstone the sediments contain marine dinoflagellates and palynomorphs of an inland flora most of the sediment accumulated in tidal channels each coal is underlain by rooted strata usually an underclay palynomorphs in the lignite suggest the peat accumulated in low lying swamps dominated by tupelo trees these swamps lay along the landward margin of a tidal channel complex the channel complex probably extended 10 to 30 km inland from the main coastline repeated regressive and transgressive episodes with corresponding expansion and contraction of the peat swamps within the estuarine complex would explain the coal bearing sequence at chacon creek east

characteristics of peat deposits in the mississippi river delta plain abstract variations in organic rich sediment peat from the mississippi river delta plain can be explained by differences in three interrelated parameters a depositional setting b balance between subsidence and detrital influx and c marine inundation variations are observed in geometry of the overall deposits organic matter content and the mineralogy of peats and related ashes using a vibracorer samples were collected from two brackish areas avery island sale cypremort and barataria basin and one freshwater area gueydan geometries of the deposits are different for the two brackish settings interdistributary peats of barataria basin tend to be discontinuous and somewhat thicker than blanket peats of avery island sale cypremort the freshwater peat is an elongate body in a pleistocene channel cut peats in all areas average 90 moisture content dried peat averages 81 3 organic matter with a bulk density of 0 12 g cm3 holocene differential compaction has been minimal less than 4 conventional ash values indicate different distributions of organic material for the two brackish areas for the area containing interdistributary peats approximately 5 0 of the subsurface contains more than 70 organic matter whereas for blanket peats 14 of the section has more than 70 organic matter mineralogical data collected on low temperature ashes indicate that major minerals in brackish peat consist of kaolinite quartz and water soluble salts while minerals from freshwater samples are primarily kaolinite and quartz x ray diffraction and electron microscopy show the presence of smectite illite abundant siliceous spicules framboidal pyrite biotite pyroxene and rutile in the insoluble fraction suitability of these deposits as coal precursors has been discussed by several workers superficial examination of data generated so far suggests that only thin coal seams with high ash would be produced however the presence of decomposing siliceous sponge spicules in the ash and the possibility of ash being leached by fresh groundwater suggest that much ash may be lost during early diagenesis hence this environment may have more potential as a modern coal forming model than first appeared

dynamics of the upper oceanic layers in terms of surface quasigeostrophy theory in this study the relation between the interior and the surface dynamics for nonlinear baroclinically unstable flows is examined using the concepts of potential vorticity first it is demonstrated that baroclinic unstable flows present the property that the potential vorticity mesoscale and submesoscale anomalies in the ocean interior are strongly correlated to the surface density anomalies then using the invertibility of potential vorticity the dynamics are decomposed in terms of a solution forced by the three dimensional 3d potential vorticity and a solution forced by the surface boundary condition in density it is found that in the upper oceanic layers the balanced flow induced only by potential vorticity is strongly anticorrelated with that induced only by the surface density with a dominance of the latter the major consequence is that the 3d balanced motions can be determined from only the surface density and the characteristics of the basin scale stratification by solving an elliptic equation these properties allow for the possibility to reconstruct the 3d balanced velocity field of the upper layers from just the knowledge of the surface density by using a simpler model that is an effective surface quasigeostrophic model all these results are validated through the examination of a primitive equation simulation reproducing the dynamics of the antarctic circumpolar current

a wave prediction system for real time sea state forecasting the considerable increase in requirements for sea state forecasts in recent years has led to development of a numerical wave forecasting system in the meteorological office this is based on a wave prediction model which combines the advantages of the parametric technique in predicting a growing wind sea with those of a discrete spectral model in the swell regime this is done using a discrete model by parametrizing the nonlinear interactions term in the energy balance equation in a way that reproduces the behaviour of the parametric model the main difficulty with the method is in the separation of wind sea and swell required to do this propagation of wave energy is performed using an accurate form of the lax wendroff integration scheme a two term representation of wave growth is used whilst dissipation is modelled by an explicit whitecapping mechanism shallow water effects are included by representations of shoaling refraction and bottom friction the operational numerical atmospheric model at the meteorological office provides the wind input an extensive program of evaluation has shown that the results provide high quality guidance with 24 hour forecasts of wave height having a r m s error ranging from 0 6 m in the southern north sea to 1 0 m east of the shetlands

the effects of altimeter instrument noise on the estimation of the wavenumber spectrum of sea surface height the wavenumber spectrum of sea surface height ssh observed by satellite altimetry was analyzed by xu and fu the spectral shape in the wavelength range of 70 250 km was approximated by a power law representing a regime governed by geostrophic turbulence theories the effects of altimeter instrument noise were assumed insignificant at wavelengths longer than 70 km the authors reexamined the assumption in the study using nearly simultaneous observations made by jason 1 and jason 2 during their cross calibration phase this study found that the white noise level of altimetry measurement was best estimated from the spectral values at wavelengths from 25 to 35 km after removing a white noise level based on such estimate from the ssh spectrum the spectral slope values changed significantly over most of the oceans a keyfinding is that the spectral slopes are generally steeper than k 22 k is wavenumber poleward of the 208 latitudes where flatter spectral slopes in some regions have previously caused problems for dynamic interpretations the new results indicate that the spectral slopes in the core regions of the major ocean current systems have values between the original geostrophic turbulence theory and the surface quasigeostrophic theory the near k 24 spectrum suggests that the sea surface height variability at these wavelengths in the high eddy energy regions might be governed by frontogenesis

global variability of the wavenumber spectrum of oceanic mesoscale turbulence abstractthe wavenumber spectra of sea surface height from satellite altimeter observations have revealed complex spatial variability that cannot be explained by a universal theory of mesoscale turbulence near the edge of the core regions of high eddy energy agreement is observed with the prediction of the surface quasigeostrophic sqg turbulence theory which has fundamental differences from that of the traditional quasigeostrophic qg turbulence theory in the core regions of high eddy energy the spectra are consistent with frontogenesis that is not fully accounted for by the sqg theory however the observations in the vast ocean interior of low eddy energy exhibit substantial differences from the predictions of existing theories of oceanic mesoscale turbulence the spectra in these regions may reflect the ocean s response to short scale atmospheric forcing and air sea interaction the observations presented in this paper serve as a test bed for new theories and ocean general circulation models

cretaceous sedimentation and tectonics tyaughton methow basin southwestern british columbia the mesozoic tyaughton methow basin straddles the fraser yalakom pasayten straight creek fypsc strike slip fault zone between six tectono stratigraphic terranes in southwestern british columbia data from hauterivian cenomanian basin fill provide constraints for reconstruction of fault displacement and paleogeography the early cretaceous eastern margin of the basin was a region of uplifted jurassic plutons and active intermediate volcanism detritus shed southwestward from that margin was deposited as the marine jackass mountain group albian inner to mid fan facies of the jackass mountain group can be correlated across the yalakom fault suggesting 150 25 km of post albian dextral offset deposits of the jackass mountain group overlap the major strike slip zone fypsc if that zone represents the eastern boundary of the tectono stratigraphic terrane wrangellia then accretion of wrangellia to terranes to the east occurred before late early cretaceous time the western margin of the basin first b

lithofacies and depositional environments of the telkwa coal measures central british columbia canada abstract albian coal measures of the skeena group in the telkwa coalfield comprise more than 500 m of conglomerate sandstone siltstone mudstone and coal that were deposited during two regressive transgressive cycles the stratigraphic sequence is divisible into four lithostratigraphic units the basal unit unit 1 is about 100 m thick and comprises conglomerate sandstone mudstone coal and seatearth deposited in a fluvial environment on a deeply eroded volcanic basement gravel and sand were deposited in braided channels and bars and mud accumulated in floodplains peat accumulated in poorly drained backswamps in the northern part of the study area coal seams thin and split a result of periodic flooding of peat swamps with sediment laden water from nearby streams deposition of unit i ended with marine transgression unit ii consists of up to 140 m of silty mudstone bioturbated and cross bedded chert and muscovite rich sandstone and rare thin carbonaceous mudstones deposited in a shallow marine environment the sands were deposited as distributary channels and mouth bars muds were deposited in bays and thin discontinuous peat accumulated in local salt marshes unit iii averages 90 m in thickness and comprises bioturbated and rippled chert and muscovite rich sandstone siltstone carbonaceous mudstone and thick coal seams deposited in a variety of low energy paralic environments sand and mud were deposited and biogenically reworked in tidal flats and siltstone accumulated in a restricted nearshore marine environment to the east peat accumulated in freshwater coastal domed mires which periodically prograded over tidal flats all but the lowermost coal seams pinch out eastward into brackish and nearshore marine sediments the ash yield of many coals increases towards their seaward margin locally the sulphur yield of the coal is high reflecting occasional inundation by brackish water the coals were deposited during regressive maximum and are characterized by an essentially vertical stacking pattern comprising an aggradational parasequence set the major coals are considered to have been deposited at the turnaround between progradation and retrogradation unit iv is over 150 m thick and is composed of chloritic sandstone overlain by silty mudstone deposited in a marine environment the basal sandstone is a transgressive lag deposit silty mudstone is the predominant lithofacies and was deposited in a nearshore shallow marine environment

time variable refraction of the internal tide at the hawaiian ridge abstractthe interaction of the dominant semidiurnal m2 internal tide with the large scale subtidal flow is examined in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on the hawaiian ridge the background fields are taken from the simple ocean data assimilation soda ocean analysis at 2 month intervals from 1992 through 2001 tides are computed with the primitive equation z coordinate harmonic analysis of tides pez hat model by 14 day integrations using soda initial conditions and m2 tidal forcing variability of the tide is found to occur primarily as the result of propagation through the nonstationary background fields rather than via generation site variability generation of incoherent tidal variability is mapped and shown to occur mostly in association with waves generated at french frigate shoals scattering near the musicians seamounts to the north of the ridge the phase coherent internal tide loses energy at a domain average rate of 2 mw m

internal tide oceanic tomography a concept of internal tide oceanic tomography itot is proposed to monitor ocean warming on a global scale itot is similar to acoustic tomography but that work waves are internal tides itot detects ocean temperature changes by precisely measuring travel time changes of long range propagating internal tides the underlying principle is that upper ocean warming strengthens ocean stratification and thus increases the propagation speed of internal tides this concept is inspired by recent advances in observing internal tides by satellite altimetry in particular a plane wave fit method can separately resolve multiple internal tidal waves and thus accurately determines the phase of each wave two examples are presented to demonstrate the feasibility and usefulness of itot in the eastern tropical pacific the yearly time series of travel time changes of the m2 internal tide is closely correlated with the el nino southern oscillation index in the north atlantic significant interannual variations and bidecadal trends are observed and consistent with the changes in ocean heat content measured by argo floats itot offers a long term cost effective environmentally friendly technique for monitoring global ocean warming future work is needed to quantify the accuracy of this technique