diurnal variability in currents and temperature on the continental shelf between central and southern california 1 long time series are used to describe the diurnal variability in the meteorological and astronomical tidal forcing and the temperature and current response on the continental shelf of california between port san luis and port hueneme spectral characteristics are used to attribute the response to each of the forcing mechanisms the diurnal temperature field is decomposed into two dominant vertical modes a surface enhanced mode is coherent with the meteorological forcing suggesting that it is a direct response to local heating and wind forcing the amplitude of the second mode is maximum at middepth spectra of this mode exhibit multiple peaks at frequencies corresponding to the astronomical tidal forcing the phase difference between the middepth mode and the tidally dominated sea level is not consistent across the region we conclude that this mode is a localized baroclinic response to the astronomical tidal forcing the diurnal velocity field is dominated by a clockwise component at the surface this component is coherent across the study region and it is also coherent with the diurnal wind stress suggesting that it is a direct response to the diurnal heating and wind forcing coherence with the surface enhanced temperature mode further confirms this a weaker barotropic counterclockwise component is also present in the diurnal velocity field spectra of this component exhibit multiple peaks at periods corresponding to the astronomical tidal forcing the phase difference between this component and the surface elevation varies little between the observational sites we conclude that this velocity component represents a barotropic response to astronomical forcing that is coherent over the study area

topographic control of wind driven circulation in the northern adriatic 1 two synoptic wind driven situations of the circulation in the northern adriatic were studied using the princeton ocean model over the northern adriatic sea napom in both situations the basin was driven by a relatively steady wind 8 m s along and across the basin over three days in the first situation 28 30 october 2008 the sse southern jugo or scirocco wind blew along the basin and in the second 19 21 march 2009 the ene bora wind blew across the basin cyclonic turn was present in the first situation while the cyclonic branch of a known double gyre circulation north of the strip of wind minima was evident in the second we show that during the jugo the model does not confirm quantitatively the simple topographic control of a wind driven circulation suitable for elongated basins while qualitatively the model meets expectations with downwind transport in shallow areas close to shorelines and upwind transport in places with greater depths during the bora wind however the wind driven circulation in the gulf of trieste is well explained by this topographic control 82 of the flux through the transect

comparison of observed hf radar and adcp measurements and computed tides in the north channel of the irish sea abstract a three dimensional high resolution grid of order 1 km model of the north channel of the irish sea incorporating a one equation turbulence energy submodel to parameterize vertical mixing is used to compute the m2 s2 n2 k1 and o1 tides elevations and currents are compared with observations with particular emphasis on a detailed comparison with current profiles recorded by two acoustic doppler current profilers adcps and hf radar measurements of the surface current the comparison with the hf radar shows small scale spatial variations in both modeled and observed currents superimposed upon the larger scale tidal currents these small scale changes appear to be associated with variations in bottom topography and can only be resolved by using fine grid models or detailed measurements computed m2 current profiles derived from a multiconstituent calculation are in excellent agreement with profiles measured by the adcps however in a single constituent m2 calculation the magnitude of the

on the nature of tidal asymmetry in the gulf of khambhat arabian sea using hf radar surface currents abstract the hourly ocean surface current observations from available high frequency radars hfr have been analyzed to i quantify the tidal constituents ii investigate the role of the bathymetry on shallow water tides and iii identify the nature of tidal asymmetry in the inverted funnel shaped gulf of khambhat gokh on the western shelf of india during may 2012 the hfr observations captured strong currents 2 0 m s 1 showing significant spring neap variations tidal harmonic analysis of the hfr currents showed that the tidal currents at the mouth are dominated by the m2 constituent with amplitude 4 5 times higher than that of k1 among the shallow water constituents m4 dominates the entire gulf with significant amplitudes 10 cm s 1 and gets amplified towards the head of the gulf 30 cm s 1 followed by ms4 comparisons with sea level heights from tide gauges show a higher correlation for the major 0 97 and shallow water 0 96 tidal constituents in terms of the order of amplitudes of the tidal constituents the circulation pattern in the gulf is predominantly driven by tidal currents with the total tidal variance being 90 of the total current variance the major contributions are from the m2 tidal currents 70 90 except at the head where the m4 component contributes significantly up to 40 the interactions with shallow bathymetry are responsible for the amplification of tidal currents in this converging channel with negligible impact from stratification during may the harmonic analysis derived relative surface phase 2m2 m4 and higher m4 m2 amplitude ratio at the head of the gulf reveal that the gulf is highly tidally asymmetric and flood dominant indicating stronger non linear tidal distortions in the nearshore regions a generalized skewness based analysis confirms the flood dominance with positive values of a morphology dependent asymmetry factor and skewness two tidal combinations m2 m4 overtide and m2 s2 ms4 compound tide are identified as the major contributors to the flow velocity skewness in the gokh with mixed mainly semi diurnal tidal regime

the emergence of volcanic oceanic islands on a slow moving plate the example of madeira island ne atlantic the transition from seamount to oceanic island typically involves surtseyan volcanism however the geological record at many islands in the ne atlantic all located within the slow moving nubian plate does not exhibit evidence for an emergent surtseyan phase but rather an erosive unconformity between the submarine basement and the overlying subaerial shield sequences this suggests that the transition between seamount and island may frequently occur by a relative fall of sea level through uplift eustatic changes or a combination of both and may not involve summit volcanism in this study we explore the consequences for island evolutionary models using madeira island portugal as a case study we have examined the geologic record at madeira using a combination of detailed fieldwork biostratigraphy and 40ar 39ar geochronology in order to document the mode timing and duration of edifice emergence above sea level our study confirms that madeira s subaerial shield volcano was built upon the eroded remains of an uplifted seamount with shallow marine sediments found between the two eruptive sequences and presently located at 320 430 m above sea level this study reveals that madeira emerged around 7 0 5 6 ma essentially through an uplift process and before volcanic activity resumed to form the subaerial shield volcano basal intrusions are a likely uplift mechanism and their emplacement is possibly enhanced by the slow motion of the nubian plate relative to the source of partial melting alternating uplift and subsidence episodes suggest that island edifice growth may be governed by competing dominantly volcanic and dominantly intrusive processes

tidal dynamics in the northern adriatic sea tides in the northern adriatic sea are investigated using two distinct numerical models first a two dimensional 2 d finite difference model is implemented with very high horizontal resolution 556 m to simulate the northern adriatic after calibration of open boundary conditions the model gives very satisfactory results the averaged vectorial difference between observed and simulated elevations is 1 3 cm for each of the seven major tidal constituents next a 3 d finite element model is applied to the entire sea in order to provide a better simulation of the tidal currents in the vicinity of the open boundary of the first model results show that the northern adriatic behaves like a narrow rotating channel in which the instantaneous sea surface elevation sse contours are aligned with the depth averaged velocity vectors and in which the sse is always higher to the right of the local current these features emphasize the rotational character that tides can exhibit in a relatively small basin wave fitting to the current elevation structure shows that semidiurnal tidal constituents are well represented with a system of two frictionless kelvin waves incident and reflected in contrast the diurnal constituents are best described as a topographic wave propagating across not along the basin from the croatian coast to the italian shore despite this obvious disparity the semidiurnal and diurnal tides can be understood as distinct members of a single family of linear waves which exist under the combined actions of gravity and topography

diurnal and semidiurnal variations in global surface wind and divergence fields diurnal and semidiurnal variations in surface winds and wind divergence over the globe 50 s 70 n are documented using 3 hourly wind observations from 10 000 land stations and available marine reports during 1976 1997 a strong diurnal cycle in surface winds is found over land areas strongest over high terrain and in summer with an amplitude of 0 6 1 1 m s for wind speed and 0 5 0 7 m s for the zonal and meridional wind components surface wind speed peaks in the early afternoon over most of the globe it is suggested that increased downward turbulent mixing of momentum during the day could be one of the main causes for the early afternoon maximum of surface wind speed the diurnal anomalies of surface wind divergence tend to be out of phase in adjacent regions in particular land areas except for extreme inland locations exhibit maximum divergence around dawn 0600 0800 local solar time lst while nearby oceanic regions have their maximum divergence in the evening 1700 1900 lst thus there is evidence for a large scale diurnal circulation in which surface air rises and converges over the continents and sinks and diverges over nearby oceans in the afternoon and early evening and the opposite occurs in the early morning over the tropical atlantic and pacific oceans 10 s 10 n a zonally coherent pattern of maximum convergence divergence north south of the equator around 0900 1200 lst is generally similar to the latitudinal profile of the mean daily divergence indicative of an enhancement of the local hadley cell around 1030 lst relative to the daily mean another zonally coherent north south dipole occurs over the north pacific with maximum surface wind divergence convergence around 0600 0800 lst in the subtropics midlatitudes this phase pattern correlates with cloud cover over the two regions over the united states surface divergence peaks around 0600 lst in the west and the east and around 2000 lst in the center

methodology for a regional tidal model evaluation with application to central california abstract observations from disparate observational assets including tide gauges moorings and high frequency hf radars were used to depict the tidal variability and to evaluate model tidal simulations for a region off central california including the monterey bay for this study the hydrodynamic model was forced only with tides derived from a large scale model for the northeast pacific ocean homogeneous density and initially horizontally uniform density stratification cases were considered the model successfully reproduced tidal sea surface height variations within the model domain as determined by comparisons with sea level or bottom pressure measured at six locations to achieve tidal currents with realistic amplitudes as determined from hf radar and moored measurements it was found that barotropic velocity as well as sea level from the large scale regional tidal model must be included in specifying the open boundary condition however even with such forcing the model with homogeneous density field under predicted the semidiurnal and diurnal barotropic currents as estimated from depth averaged currents measured at 11 locations in the diurnal frequency band the observed surface and nearshore depth averaged currents are likely influenced by meteorological forcing which was not included in the model the hf radar measured surface tidal currents both semidiurnal and diurnal are consistent from year to year and between the winter season and the entire year semidiurnal surface tidal currents derived from year long hf radar measurements do not resemble either the modeled or measured barotropic current fields rather they exhibit amplitudes and small scale spatial variability indicative of the presence of internal tides thus indicating that model derived barotropic tidal currents cannot be validated over large spatial extents using long time series of hf radar derived surface currents with initially horizontally uniform vertical density stratification the model produced surface currents with spatial variability and amplitude range comparable to what was derived from hf radar surface current measurements but the point by point comparisons are not impressive for this region of complex topography likewise the subsurface current comparisons performed at four deepwater locations show considerable model data differences possible reasons for these disparities include the effects of atmospheric forcing spatially and temporally varying stratification remotely generated coastally trapped waves and remotely generated internal tides

february 2003 marine atmospheric conditions and the bora over the northern adriatic 1 a winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern adriatic mean february winds are from a northeasterly direction over most of the adriatic and a more northerly direction along the western coast wind speeds are fastest in jets over the ne coast during bora events and weakest in the mid northwestern adriatic diurnal air temperature cycles are smallest on the ne coast and largest in the midwestern adriatic the maximum sea air difference is 10 c on the eastern coast and near zero on the midwestern adriatic boras are northeasterly from wind events that sweep off croatia and slovenia bringing slightly colder and drier air over the northern adriatic the main bora season is december to march winter 2002 2003 was normal for bora events synoptic scale temporal variations are correlated over the northern adriatic fastest bora winds and highest wind stress over the northern adriatic is concentrated in four topographically controlled jets the strongest is the senj jet while the trieste jet extends across the entire northern adriatic between each two jets is a weak wind zone the greatest mean net heat loss is in bora jets in the ne adriatic where it was 438 w m 2 and is weakest in the midwestern northern adriatic where it was near zero wind stress is concentrated over the ne half of adriatic in four bora jets while wind stress is weak in the nw adriatic there is significant variation in wind stress mean and standard deviation structure over the northern adriatic with each bora event

surface current patterns in the northern adriatic extracted from high frequency radar data using self organizing map analysis 1 a network of high frequency hf radars was installed in the northern adriatic in the second half of 2007 aimed to measure surface currents in the framework of the north adriatic surface current mapping nascum project this study includes a detailed analysis of current measurements from february to august 2008 a period in which three radars were simultaneously operational current patterns and temporal evolutions of different physical processes were extracted by using self organizing map som analysis the analysis focused on subtidal frequency band and extracted 12 different circulation patterns on a 4 3 rectangular som grid the som was also applied on a joint data set that included contemporaneous surface wind data obtained from the operational hydrostatic mesoscale meteorological model aladin hr the strongest currents were recorded during energetic bora episodes being recognized by several current patterns and having the characteristic downwind flow with magnitudes exceeding 35 cm s at some grid points another characteristic wind the sirocco was represented by three current patterns while the remaining current structures were attributed to weak winds and the residual thermohaline circulation a strong resemblance has been found between som patterns extracted from hf radar data only and from combined hf radar and wind data sets revealing the predominant wind influence to the surface circulation structures and their temporal changes in the northern adriatic these results show the som analysis being a valuable tool for extracting characteristic surface current patterns and forcing functions

modeling tides in monterey bay california abstract in the process of developing a tide permitting coastal ocean forecasting system tidal signals are added to an oceanic general circulation model for monterey bay california the model which is configured from the regional ocean modeling system roms has three one way nested domains with the finest resolution of 1 6 km in the horizontal direction and 32 levels in the vertical direction in present research the tidal simulation of the system is validated against tide gauges adcp current observations high frequency radar surface current observations and compared with the output from two barotropic tidal models the results indicate that the barotropic tides from the model compare well with observations in terms of sea surface height with discrepancies in amplitude of less than 10 of the amplitude of the most energetic m 2 constituent however the discrepancy for the barotropic tidal currents can reach 30 among models with similar accuracy in sea surface height the generation and propagation of baroclinic tides associated with the monterey submarine canyon are qualitatively reproduced by the model with weaker strength the surface tidal current simulation is improved especially in terms of magnitude when the model has a more realistic stratification through changes in both barotropic and baroclinic tidal currents

tidal currents on the central oregon shelf models data and assimilation 1 measurements of tidal currents on the central oregon shelf are available from several sources including recent high frequency hf coastal radar and acoustic doppler profiler adp deployments and historical current moorings in this paper we use a generalized inverse gi approach to compare these data to and then assimilate them into numerical models for the barotropic tides harmonic analysis of the data in short time windows using a modified admittance approach reveals that tidal currents on the oregon shelf are highly variable in time and can contain significant baroclinic components data from the winter months when waters on the shelf are only weakly stratified are found to be most nearly barotropic and thus most reasonable for assimilation into the shallow water equations model the various data sources are used in several different combinations for assimilation and validation forcing the prior forward model with normal flow open boundary conditions obtained from a regional barotropic inverse model results in semidiurnal barotropic currents that are consistent within estimated error limits with all available data in contrast diurnal currents on the shelf are very sensitive to details of the model configuration and are significantly improved by data assimilation very similar solutions result from assimilation of either the hf radar or adp data sets the high sensitivity of the diurnal band currents can be understood dynamically in terms of trapped shelf waves a short 85 km long section of shelf off the central oregon coast is wide enough to allow first mode barotropic shelf waves at the subinertial diurnal frequencies this results in locally resonant large amplitude diurnal tidal currents that are very sensitive to details in the local forcing and hence quite variable in time

numerical study of the role of wind forcing and freshwater buoyancy input on the circulation in a shallow embayment gulf of trieste northern adriatic sea 1 this paper investigates the role of wind forcing and river discharge on a small scale shallow embayment the gulf of trieste the qualitative and quantitative analysis of these dominant processes is carried out using a high resolution numerical model initialized and forced with experimental data the simulations are focused on short term transient events which occurred during the stratification season spring and summer two significant case studies are analyzed in detail a strong wind event during summer and a river flood during spring the model output is also checked against the results of a nondimensional scale analysis and against buoy and satellite observed data these comparisons show a good correlation validating the numerical simulations for the two case studies the model shows that strong wind events blowing on stably stratified water cause coastal upwelling and almost entirely mix the water column in a few hours strong wind driven currents can flush the whole basin in almost 3 days on the contrary river floods affect mainly the upper layer down to 5 m the circulation is estuarine with a sharp vertical density gradient and horizontal fronts at the interface between plume freshwater and ambient salty water given the length scale of the basin the effect of rotation is weak and a local coastal current in geostrophic balance is not formed during the simulated time period 20 days

validation of hf radar sea surface currents in the malta sicily channel abstract a network of high frequency radar hfr stations runs operationally in the malta sicily channel msc central mediterranean sea providing sea surface current maps with high temporal 1 h and spatial 3 3 km resolutions since august 2012 comparisons with surface drifter data and near surface acoustic doppler current profiler adcp observations as well as radar site to site baseline analyses provide quantitative assessments of hfr velocities accuracy twenty two drifters were deployed within the hfr domain of coverage between december 2012 and october 2013 additionally six adcp vertical current profiles were collected at selected positions during a dedicated field survey external radio frequency interferences lead to significant gaps in the hfr coverage which were minimized by an interpolation technique applied to the surface current fields the validation of hfr velocities was first performed for each individual station in the network using data generated with both the ideal and the measured antenna patterns the validation was then repeated with pairs of hfr stations using the site to site baseline error analysis the analysis confirms that the baseline error estimations and the full validation metrics for this hfr frequency band are consistent and in some aspects superior when compared to results from similar studies in other regions the validation with drifter tracks suggests that the adopted interpolation procedure does not in general impact on the comparison metrics but may introduce biases when used to extrapolate currents in regions where radar geometrical constraints are suboptimal the analysis of the percentage of contribution of individual hfr stations shown that the quality of hfr data is influenced by the network geometry

a record of ultrahigh temperature metamorphism in the dabie orogen during triassic continental collision abstract ultrahigh temperature uht metamorphism is traditionally recognized by the development of characteristic mineral associations in mg al rich metapelitic rocks however recognition of uht metamorphism in non supracrustal rocks is more difficult uht metamorphic conditions are recorded by a migmatite from the north dabie terrane ndt of the dabie orogen east china the migmatite is composed of intercalated layers of melanosome and k feldspar rich leucosome zircon grains in the migmatite have a core rim structure comprising a metamorphic core and an anatectic rim the metamorphic cores have low u contents mainly

tidal currents in the northwestern adriatic high frequency radio observations and numerical model predictions the results of a two year long deployment of high frequency radars along the italian coast of the northern adriatic are analyzed to characterize the surface tidal currents m2 and k1 ellipses are aligned with the basin axis and exhibit large eccentricities in the middle of the basin decreasing toward the italian coast comparisons are made with a 3d finite element non linear numerical model of the tides complex correlations between modeled and observed tidal currents show a remarkable agreement in the middle of the basin with magnitudes reaching 0 985 and average phases of 6 4 deg however the magnitudes drop to 0 5 within 20 30 km from the italian coast where the modeled currents amplitudes are underestimated by 2cm s and the phases lag the observed phases by 60 deg this shallow region less than 30 m deep is characterized by low salinity water originating at the po river and laterally sheared coastal flows the radars may have captured the influence of stratification or mean sheared flows both absent from the model the model parameterization of bottom friction may also inadequately represent the effects of real bottom friction on the vertical current shear

diurnal period wind stress and current fluctuations over the continental shelf off northern california diurnal period wind stress and current fluctuations measured over the continental shelf off northern california during the coastal ocean dynamics experiment in the summers of 1981 and 1982 are examined the diurnal currents are strongly surface intensified with amplitudes of up to 20 cm s 1 at depths of less than 35 m the diurnal currents are nonstationary and their amplitude is well correlated with the amplitude modulation of the local diurnal wind stress beneath the surface layer the diurnal current vectors rotate clockwise with ellipse semi major axes of 1 to 3 cm s 1 a mixed layer model driven with diurnal wind stress and surface heat flux produces currents similar to those observed in the upper water column the deeper currents are consistent with the combination of a freely propagating kelvin and first mode coastal trapped wave and over the inner shelf with the interior flow forced by the diurnal wind stress in the presence of a coast

comparison of observed hf radar adcp and model barotropic tidal currents in the new york bight and block island sound abstract a three dimensional primitive equation model is used to simulate the barotropically forced semidiurnal tidal currents in the new york bight nyb and block island sound bis model tidal velocity ellipses are verified at historical current meter locations and with measurements from acoustic doppler current profilers adcps and hf radar codar the model reproduces well the regional tidal flow pattern as well as the vertical tidal velocity structure the model misfits typically are 2 4 cm s in amplitude and 5 7 in orientation through comprehensive skill assessment the model s capacity of simulating the three dimensional barotropic tidal currents is clearly demonstrated moreover it is shown that the integrity of hf radar measurements can be assured by verifying with model tidal ellipses

hf radar observations of surface circulation off bodega bay northern california usa 1 two high frequency radar stations codar were installed along the northern california coast in may 2001 comparisons of radar data with acoustic doppler current profiler adcp current data and near surface drifter tracks indicate considerable agreement with minimum rms differences of order 0 05 0 15 m s and average drifter hf radar track separation rates of 5 3 km d radar data resolve the three main sources of intraseasonal current variability in the area 1 upwelling relaxation dynamics 2 tidal and diurnal forcing and 3 inertial currents subtidal fluctuations are the largest component of variability accounting for 45 75 of the variance wind driven dynamics are the dominant source of this subtidal variability 67 of subtidal variability both upwelling and relaxation periods exhibit consistent patterns of surface velocity with nearshore currents being slower and more poleward than offshore currents which are strongly equatorward analysis of tidal and inertial variability indicate that current fluctuations are polarized toward clockwise rotation and are generally weaker and more linearly polarized near the coast m2 tidal current ellipses switch direction of rotation at the shelf break suggesting the presence of internal tidal waves currents in all frequency bands are deflected and accelerated around pt reyes and there are indications of increased current variability and changes in flow direction near cordell bank the presence of considerable cross shore and alongshore gradients in the strength and direction of surface flow patterns and in particular weak poleward currents over the inner shelf could have important consequences for plankton retention in the area

surface current patterns in front of the venice lagoon abstract surface patterns of the low frequency current in a 20 30 km region in front of the venice lagoon were analysed from a 13 month long hf radar data set surface circulation was related to prevalent wind regimes in the area and to the tidal flow through the lagoon inlet three different categories of wind forcing were defined bora ne wind sirocco se wind and finally the category containing all other wind directions and calms winds lower than 3 m sec mean flow and vorticity spatial distributions were discussed for different wind conditions the coastal area about 5 km wide is characterized by a flow field with maximum vorticity outside the coastal boundary layer the interior flow is part of the adriatic basin wide cyclonic circulation two counter rotating vortices of the dimension of about 4 5 km were evidenced in the average flow field in front of the lagoon inlet malamocco inlet in all situations except for the bora the vortex pair is probably associated with the tidal flow through the inlet the bora wind induces a strong southward coastal jet detached from the coast by about 5 km homogenizing the flow and eliminating the dipole the average coastal flow pattern in calm wind conditions was also analysed as a function of the strong inflow outflow currents in the inlet 0 7 m s 1 from the lagoon inlet in both cases the vorticity pattern is similar with the negative vorticity to the left of the inlet and positive to the right looking seaward

surface circulation at the strait of gibraltar a combined hf radar and high resolution model study observations from a high frequency radar system and outputs from a high resolution operational ocean model working at the strait of gibraltar have been analyzed and compared during the period february 2013 to september 2014 in order to evaluate their capability to resolve the surface circulation of the region the description of the mean circulation patterns has been statistically assessed showing good agreement particularly in the central region of the strait corresponding with the atlantic jet aj stream although some short scale features are not reproduced by the model in the frequency domain very high concordance is observed tidal maps of diurnal and semidiurnal constituents are in good agreement with previous observations the analysis of the model and radar response to the wind forcing reveals that the low resolution of the model wind forcing field and its deeper superficial level smoothes the wind effect on the simulated currents the first three eof modes account for the 86 of model and radar variances the coincidence between the observed and simulated patterns is very significant for the first two modes which account for the mean velocity field and the latitudinal shifting of the aj consequence of the flow topography interaction the third mode captures the wind induced circulation and greater discrepancies are found in this case results underline the complementary character of both systems radar observations improve the model description resolving short scale processes while the model completes the radar information when the time or spatial coverage is poorer

surface circulation in the gulf of trieste northern adriatic sea from radar model and adcp comparisons 1 high resolution high frequency hf radar observations of surface currents in the gulf of trieste got are presented and compared to moored subsurface current measurements and to high resolution simulations from the northern adriatic princeton ocean model napom oceanographic model dominant circulation modes of the got were resolved and numerical model capabilities in reconstructing them were assessed the time frame covers march 2011 through october 2012 napom reconstructs the dominant surface circulation features observed by the radar such as the general basin wide cyclonic circulation scheme and the coastal jet outflowing the got but is in general less energetic than radar currents comparisons between radar adcp and model currents suggest that the model underestimates originate within the low frequency diurnal semidiurnal and inertial bands and that both radar and model currents do not reproduce the diurnal tidal ellipse structure observed by the moored current meter however radar model results for the semidiurnal tides are spatially consistent using empirical orthogonal function eof decomposition the coherent spatial scales and corresponding temporal scales were extracted findings suggest that hf radar current observations complement model simulations in regions of enhanced topographic variability where variance of model currents at the surface is distorted by the effects of the sigma layer grid on the contrary model results complement radar observations in areas with poor radar coverage and furthermore provide spatial and temporal continuity of ocean state forecasts

the adriatic sea general circulation part ii baroclinic circulation structure abstract in the second part of the paper dedicated to the adriatic sea general circulation the horizontal structure of the hydrographic parameters and dissolved oxygen fields is described on a seasonal timescale maps of temperature and salinity climatological fields reveal the enhanced seasonal variability of the adriatic sea which at the surface is associated with the major dilution effects of river runoff the density and derived dynamic height fields show for the first time the baroclinic geostrophic structure of the general circulation winter is dominated by compensation effects between temperature and salinity fronts along the western coastline the resulting baroclinic circulation is weak and suggests the presence of barotropic current components not accessible by the dataset spring and summer seasons have the smallest spatial scales in the temperature and salinity fields and stronger subbasin scale gyres and current systems which have been classified in a schematic representation of the circu