analysis of the mesoscale structure in the imecocal region off baja california from hydrographic adcp and altimetry data we present geostrophic velocities obtained using hydrographic altimeter data and direct measurements of currents from 11 cruises offshore of baja california from january 2000 to july 2002 the study area was dominated by meanders and eddies in geostrophic balance two mechanisms of eddy generation were observed the first associated with the geometry of the coastline and the second a product of the cooling of the california current and the california undercurrent from the south there were two persistent eddies observed during the study the first eddy was offshore of bahia vizcaino and had an anticyclonic circulation situated in the southern region the rotation of the second eddy was dependant on which current was first to enter the transition zone along the coast spring was a transition period characterized by the formation of meanders the summer brought a period of eddy generation along the coast autumn and winter were marked by a separation of eddies from the coast and their subsequent drift towards the west the phase velocity of the mesoscale eddies was in accordance with the theory of the linear propagation of a rossby wave

a cool anomaly off northern california an investigation using ir imagery and in situ data satellite ir imagery and in situ hydrographie data are used to understand better the mesoscale variability of the california current system and to explore the relation of its surface and subsurface thermal structures in august 1982 one of the cool filaments commonly seen in satellite ir images during summer off northern california was sampled hydrographically during an optoma ocean prediction through observation modeling and analysis cruise based on the cool anomaly seen in a series of ir images and the in situ hydrographie data and based on geostrophic calculations a jet entrained upwelled coastal water and advected it rapidly through the warmer waters offshore providing an important cross shore transfer process the anomaly was about 50 km wide and extended vertically to about 40 m the temperature patterns at the surface were well correlated with those to about 30 m below 50 m the surface temperature was better correlated with horizontal temperature gradients i e the thermal wind consistent with strong horizontal advection by the geostrophic jet the cool anomaly was also relatively dense based on investigation of the t s properties the coastal water had been diluted through mixing with columbia river plume water on the northern edge of the anomaly near the temperature front in the shoreward sampled portion of the anomaly and just south of the anomaly interleaving occurred there was also a surface saline anomaly embedded in the cool anomaly near the temperature front the location of the temperature front in the in situ data and in the ir imagery corresponded well the temperature front was tracked in a series of ir images over 2 weeks the reorientation of the seaward extremity of the anomaly from westward to northwestward and the southwestward displacement of its southern boundary at speeds of 2 to 5 km d were consistent with the propagation of mesoscale features evident in successive quasi synoptic surface dynamic topography maps the southwestward displacement was probably also related to surface ekman transport

altimeter derived variability of surface velocities in the california current system 2 seasonal circulation and eddy statistics abstract satellite surface height and temperature fields are used to examine the seasonal surface circulation in the california current system in spring and summer an equatorward jet develops next to the coast with an initial latitudinal structure that responds to the latitudinal distribution of equatorward alongshore winds this jet moves offshore from spring to fall and develops meanders and closed eddies that contribute eddy kinetic energy and water mass properties to the nearby deep ocean higher eke appears first in spring near the coast and moves offshore with the seasonal jet along altimeter tracks parallel to the coastline 200 and 400 km offshore the greatest eke is found in summer and fall respectively with wavelengths of approximately 300 km these are the wavelengths of the largest meanders and the distance between the largest eddies visible in altimeter snapshots of the jet at 600 800 km offshore the wavelengths are generally smaller 100 150 km similar to eddy sizes reported by others for the quiescent northeast pacific some energy with longer wavelengths arrives at the track 600 km offshore in winter and 800 km offshore in spring which we interpret as the most offshore extension of the eke generated by the jet and eddy system closer to the coast in the previous spring and summer a sequence of snapshots from october 1992 to october 1993 shows details of the evolution of the jet and eddy system over one complete annual cycle

seasonal variability in meanders of the california current system off vancouver island satellite infrared images taken over the past few years reveal seasonal variations in the meanders of the california current system ccs off vancouver island the ccs exhibits meanders with wavelength between 120 and 150 km in both winter and spring when the upper ocean current all flows northwestward or southeastward respectively in summer the ccs includes the california undercurrent which flows northwestward beneath the southeastward surface current and has shorter wavelength 75 80 km meanders around the end of august these shorter scale meanders are engulfed by the longer 150 km meanders finally in the fall eddies are detached from the offshore extensions of the longer meanders a linear stability theory using a four layer model of the ccs successfully predicts the wavelengths in the winter and spring but not in the summer and fall the meander evolution observed in summer and fall is instead simulated by using a nonlinear numerical model in a domain with topographic obstacles selected to match the alongshore variations in the continental slope the topographic features with a spatial periodicity of 75 km act as a trigger to initiate the short wavelength 75 km meanders following this these 75 km meanders grow because of baroclinic instability the 75 km meanders which have grown to large amplitudes are replaced by longer 150 km meanders because of nonlinear interactions between these two scales of meanders cyclonic eddies are finally shed from the longer meanders

mechanisms for the emergence of ocean striations in the north pacific recent observations suggest that the mean mesoscale oceanic zonal velocity field is dominated by alternating jet like features often referred to as striations here the generating dynamics of northeast pacific striations are explored with a set of 120 year eddy permitting model simulations simulations are conducted with decreasing complexity toward idealized configurations retaining the essential dynamics and forcing necessary for striation development for each simulation we diagnose the spin up of the ocean model and the sensitivity of striation generation to topography coastal geometry and wind stress which modulates the gyre circulation and the nonlinearity of the flow field results indicate that northeast pacific striations develop predominantly at the eastern boundary and migrate westward in congruence with beta plumes in both the nonlinear and quasi linear regimes mean striations are governed by coastline geometry which provides quasi steady vorticity sources energized by eastern boundary current instabilities

wind forced modeling studies of currents meanders and eddies in the california current system this process oriented study of the california current system ccs uses a high resolution multilevel primitive equation ocean model on a plane to isolate the response of that eastern boundary oceanic regime to temporal and spatially varying wind forcing to study the generation evolution and maintenance of many of the observed features such as currents meanders and eddies in the ccs the model is forced from rest with seasonal climatological winds in response to the prevailing wind direction surface equatorward currents develop along with upwelling of cooler water along the coast and a poleward undercurrent baroclinic barotropic instabilities in the equatorward surface current and poleward undercurrent result in the generation of meanders near the coast as the meanders intensify cold upwelling filaments develop along the coast and subsequently extend farther offshore in time the meanders form both cyclonic and anticyclonic eddies which subsequently propagate farther offshore longer simulation times 3 4 years in which a quasi equilibrium state for the ccs is reached show a seasonal cycle in response to the wind forcing for the coastal currents upwelling and filaments the meanders and eddies however can be quasi permanent as well as seasonal features the quasi permanent features play a significant role in modifying coastal currents upwelling and filaments which leads to large temporal and spatial variability in the ccs in a sensitivity study the results from several numerical experiments are used to examine the dependence of the generation of the currents meanders and eddies on the type of coriolis parameterization wind forcing and coastline geometry both the meridional variability of plane and the alongshore component of the wind stress are shown to be key ingredients for generating realistic vertical and horizontal structures for the cores of the surface equatorward and the subsurface poleward currents with such structures the currents are baroclinically and barotropically unstable resulting in the generation of meanders filaments and eddies irregularities in the coastline geometry are shown to be important for anchoring upwelling and filaments as well as for enhancing the growth of meanders and eddies cyclonic eddies tend to form in the vicinity of capes while anticyclonic eddies tend to form in the coastal indentations between capes the region off cape blanco is identified as the location where the coastal equatorward flow off oregon leaves the coast to develop a meandering jet off california the results from these experiments support the hypothesis that wind forcing and coastline irregularities on a beta plane are important mechanisms for the generation of many of the observed features of the ccs

vertical structure of mesoscale eddies in the eastern south pacific ocean a composite analysis from altimetry and argo profiling floats 1 the mean vertical structure of mesoscale eddies in the peru chile current system is investigated by combining the historical records of argo float profiles and satellite altimetry data a composite average of 420 526 profiles acquired by argo floats that surfaced into cyclonic anticyclonic mesoscale eddies allowed constructing the mean three dimensional eddy structure of the eastern south pacific ocean key differences in their thermohaline vertical structure were revealed the core of cyclonic eddies ces is centered at 150 m depth within the 25 2 26 0 kg m 3 potential density layer corresponding to the thermocline in contrast the core of the anticyclonic eddies aes is located below the thermocline at 400 m depth impacting the 26 0 26 8 kg m 3 density layer this difference was attributed to the mechanisms involved in the eddy formation while intrathermocline ces would be formed by instabilities of the surface equatorward coastal currents the subthermocline aes are likely to be shed by the subsurface poleward peru chile undercurrent in the eddy core maximum temperature and salinity anomalies are of 1 c and 0 1 with positive negative values for aes ces this study also provides new insight into the potential impact of mesoscale eddies for the cross shore transport of heat and salt in the eastern south pacific considering only the fraction of the water column associated with the fluid trapped within the eddies each ce and ae has a typical volume anomaly flux of 0 1 sv and yields to a heat and salt transport anomaly of 1 3 1011 w and 3 8 103 kg s 1 respectively

a nested grid model of the oregon coastal transition zone simulations and comparisons with observations during the 2001 upwelling season 1 the oregon coastal transition zone octz extends several hundred kilometers offshore where shelf flows interact with the northern california current a primitive equation numerical ocean model is used to study the upwelling circulation in this region from 1 may to 1 november 2001 this octz model obtains initial and boundary conditions from a larger scale model of the california current system and forcing from a regional atmospheric model product the model results are compared with extensive in situ and remotely sensed data and the model is found to provide a realistic representation of flows both over the shelf and in the broader octz simulation of coastal sea level and shelf currents over the complex topography of the central oregon coast is improved quantitatively relative to previous regional models a particularly significant qualitative improvement is realistic representation of coastal jet separation and eddy formation offshore of cape blanco three dimensional lagrangian analysis of water parcel displacement shows that the surface waters inshore of the separated jet are upwelled from near the bottom along the shelf as far north as 45 5 n a large eddy which incorporates some of this upwelled water and carries it farther westward forms offshore in the late summer ensemble simulations show a distinction between the strongly deterministic response to wind forcing over the shelf and the more unstable less predictable jet separation and offshore eddy formation processes in the region near cape blanco

the large scale summer circulation of the california current satellite data from the geosat altimeter and the advanced very high resolution radiometer avhrr are used to show the large scale structure of the surface circulation of the california current system in summer these data show the connection between an equatorward jet and temperature front off oregon that lies within 100 km of the coast similar to that first observed in the 1960 s and 1970 s and a jet that meanders along the convoluted offshore edge of a temperature front off california as repeatedly observed in the 1980 s

cetacean distributions relative to ocean processes in the northern california current system abstract associations between cetacean distributions oceanographic features and bioacoustic backscatter were examined during two process cruises in the northern california current system ccs during late spring and summer 2000 line transect surveys of cetaceans were conducted across the shelf and slope out to 150 km offshore from newport oregon 44 6 n to crescent city california 41 9 n in conjunction with multidisciplinary mesoscale and fine scale surveys of ocean and ecosystem structure occurrence patterns presence absence of cetaceans were compared with hydrographic and ecological variables e g sea surface salinity sea surface temperature thermocline depth halocline depth chlorophyll maximum distance to the center of the equatorward jet distance to the shoreward edge of the upwelling front and acoustic backscatter at 38 120 200 and 420 khz derived from a towed undulating array and a bioacoustic system using a multiple logistic regression model 60 2 and 94 4 of the variation in occurrence patterns of humpback whales megaptera novaeangliae during late spring and summer respectively were explained sea surface temperature depth and distance to the alongshore upwelling front were the most important environmental variables during june when humpbacks occurred over the slope 200 2000 m during august when humpbacks concentrated over a submarine bank heceta bank and off cape blanco sea surface salinity was the most important variable followed by latitude and depth humpbacks did not occur in the lowest salinity water of the columbia river plume for harbor porpoise phocoena phocoena the model explained 79 2 and 70 1 of the variation in their occurrence patterns during june and august respectively during spring latitude sea surface salinity and thermocline gradient were the most important predictors during summer latitude and distance to the inshore edge of the upwelling front were the most important variables typically a coastal species harbor porpoises extended their distribution farther offshore at heceta bank and at cape blanco where they were associated with the higher chlorophyll concentrations in these regions pacific white sided dolphin lagenorhynchus obliquidens was the most numerous small cetacean in early june but was rare during august the model explained 44 5 of the variation in their occurrence pattern which was best described by distance to the upwelling front and acoustic backscatter at 38 khz the model of the occurrence pattern of dall s porpoise phocoenoides dalli was more successful when mesoscale variability in the ccs was higher during summer thus the responses of cetaceans to biophysical features and upwelling processes in the northern ccs were both seasonally and spatially specific heceta bank and associated flow topography interactions were very important to a cascade of trophic dynamics that ultimately influenced the distribution of foraging cetaceans the higher productivity associated with upwelling near cape blanco also had a strong influence on the distribution of cetaceans

hydrographic observations off northern california during may 1977 a hydrographic survey of 286 ctd stations was made in may 1977 in the region between 37 sup 0 n i e near san francisco and 43 sup 0 n i e cape blanco in southern oregon coastal upwelling was most intense south of cape mendocino at 300 m an intense temperature and salinity frontal zone occured between 38 sup 0 n and 39 sup 0 n the dynamic height topographies 0 900 dbar and 300 900 dbar contained regions of highs and lows with length scales of 100 150 km north of cape mendocino the warm saline water identified as the poleward california undercurrent was not observed and the transport integrated above 900 dbar was southward

block coals from indiana inferences on changing depositional environment significant differences in coal petrography palynology and coal quality were found between the lower block and upper block coal members brazil formation pennsylvanian in daviess county indiana the lower block coal member ranges in thickness from 51 to 74 cm and the upper block coal member ranges from 20 to 65 cm average sulfur content and ash yield of the lower block coal 0 98 7 65 are lower than in the upper block coal megascopically the coals show distinct differences the lower block is a banded coal with numerous thin fusain horizons and a thin clay parting in the lower third of the seam the upper block coal has a dulling upward trend with a bright clarain found at the base that grades into a clarain and then into a durain in the upper portion of the seam vitrinite content of the lower block coal ranges from 63 to 78 with the highest vitrinite content found in the middle portion of the seam in the upper block coal vitrinite content ranges from 40 to 83 with the highest values found in the lower part of the seam ash yield is higher in the upper part of the upper block coal reaching up to 40 the lower block coal is dominated by lycopod trees and tree ferns the upper block coal shows marked differences in spore assemblages between lower and upper parts of the seam the lower half is dominated by large lycopod trees and tree ferns similar to the lower block coal the upper half is dominated by small lycopods mainly densosporites and radiizonates these differences between the lower block and upper block coal members are significant correlation tools applicable to mining exploration and chronostratigraphy

upwelling filaments off cap blanc interaction of the nw african upwelling current and the cape verde frontal zone eddy field 1 the hydrographical and dynamical properties of the upwelling filaments forming off cap blanc mauritania are investigated using remotely sensed and in situ data collected in april may 2009 during the strongest upwelling season the area is situated at the southern edge of the nw african upwelling system where the cape verde frontal zone cvfz separates warmer saltier north atlantic central water nacw and cooler fresher south atlantic central water sacw sea surface temperature images indicated the presence of an upwelling filament extending 280 km offshore rooted over the cap blanc promontory and entrained around a warm core anticyclonic eddy after this filament started to decay a new cold filament developed at the approximate same location high resolution moving vessel profiler mvp and acoustic doppler current profiler adcp surveys of these mesoscale structures revealed that both filaments were carrying south atlantic central water sacw offshore through an intense jet like flow similarity of the relative vorticity structure across the filament with that of the tangent eddy suggested that the latter was responsible for the offshore current tracking of this eddy in altimetric data demonstrated that it originated from the cvfz as implied by its hydrographic structure altimetric data also revealed that another anticyclonic structure centered over the cap blanc promontory was responsible for the northwestward advection of sacw into the base of the filament the results support the idea that some upwelling filaments can be produced by the interaction of an external eddy field including topographic eddies with the upwelled water

satellite observations and modeling of meanders in the california current system off oregon and northern california abstract infrared satellite images from the west coasts of oregon and northern california are used to identify meander patterns in sea surface temperature which appear as large cold tongues extending offshore two relatively long series of images from 1982 and a few examples from 1980 and 1983 demonstrate the evolution of the cold tongues from an initial variety of scales 60 200 km to the fastest growing waves 110 130 km and then finally to tongues with longer wavelengths 400 km this is observed to occur over periods of about three months in summer and fall when the coastal circulation is composed of a southward surface current over a northward undercurrent the initial shorter scale features are believed to be excited by the interaction between the mean current and the coastal topography baroclinic instability associated with the vertical shear between the surface current and the undercurrent is found to be responsible for the growth of the features observed in the satellite imagery a nonlinear

the california current system in relation to the northeast pacific ocean circulation abstract the california current system is described in its regional setting using two modern datasets argo provides a broadscale view of the entire eastern north pacific ocean for the period 2004 2010 and the high resolution xbt network includes transects from honolulu to san francisco 1991 2010 and to los angeles 2008 2010 together these datasets describe a california current of 500 800 km width extending along the coast from 43 n to 23 n the mean southward transport of the california current is about 5 sv off central and southern california with about 2 5 sv of northward flow on its inshore side interannual variations are 50 or more of the mean transports the salinity minimum in the core of the california current is supplied by the north pacific current and by freshwater from the northern continental shelf and modified by alongshore geostrophic and across shore ekman advection as well as eddy fluxes and air sea exchange the heat and freshwater content of the california current vary in response to the fluctuating strength of the alongshore geostrophic flow on its offshore side the california current is influenced by north pacific intermediate waters at its deepest levels and by eastern subtropical mode waters on shallower density surfaces in total the sources of the california current its alongshore advection and its strong interactions with the inshore upwelling region and the offshore gyre interior combine to make this a rich and diverse ecosystem the present work reviews previous contributions to the regional oceanography and uses the new datasets to paint a spatially and temporally more comprehensive description than was possible previously

vertical variations of mercury in pennsylvanian coal beds from indiana abstract twenty three in situ coal sections were sampled in indiana mines to investigate mercury hg concentrations with a special reference to in seam vertical variations in hg distribution in addition to raw coal corresponding float fractions were also analyzed to evaluate the effectiveness of hg reduction during conventional pre combustion washing hg content in indiana coals in the locations studied averages 0 11 mg kg which after recalculation into equal energy units corresponds to 9 2 lb hg 1012 btu 39 5 kg hg 1010 mj hg content is reduced after washing to 0 07 mg kg on average corresponding to an equal energy hg loading of 5 2 lb hg 1012 btu 22 3 kg hg 1010 mj a large portion of hg appears to be associated with pyrite as in the springfield coal member of the petersburg formation pennsylvanian in the samples from the danville coal member of the dugger formation pennsylvanian hg is associated to a larger extent with organic matter large differences in hg content may exist between different portions of a coal bed in a single location indicating that very careful complete sampling is necessary to get representative hg concentration data

observation and modeling of satellite sensed meanders and eddies off vancouver island abstract a long time series of satellite infrared images spanning the period 21 july 8 october 1980 reveals the evolution of long 160 km and short 80 km wavelength meanders of the california current system off vancouver island midway in the series strong interactions occurred between the two meander scales although the shorter meanders were initially more energetic they were eventually dominated by the longer meanders near the end of the time series detached mesoscale eddies were formed from the longer meanders current meter data from the period before meander growth clearly indicates the presence of a strong vertical shear near 150 m which consists of a southeastward surface current and a northwestward undercurrent it is argued in this paper that the observed shear flow is the energy source for the meanders and eddies seen in the satellite images a four layer quasi geostrophic model is used to represent the california current system off vancouver island the two upper layers represent the

differential insect and mammalian response to late quaternary climate change in the rocky mountain region of north america abstract of the 200 beetle species identified from rocky mountain late pleistocene insect faunal assemblages 23 are no longer resident in this region none of the 200 species is extinct in contrast to this only 8 of 73 identified mammal species from rocky mountain late pleistocene assemblages are no longer resident in the rockies and 12 species are now extinct since both groups of organisms are highly mobile it would appear that their responses to the large scale fluctuations of climate associated with the last 125 000 years have been considerably different most strikingly contrasting with the insects there are no mammals in the rocky mountain late pleistocene fossil record that are found exclusively today in the pacific northwest pnw region the pnw does have a distinctive modern mammalian fauna but only one of these keen s myotis has a fossil record outside the pnw region in the eastern and central united states no modern pnw vertebrate species have been found in any rocky mountain fossil assemblages based on these data it appears that there has been little or no mammalian faunal exchange between the pnw region and the rocky mountains during the late pleistocene or holocene this is in stark contrast to the fossil beetle record where pnw species are a substantial component in many faunas right through to the late holocene

sea surface temperature fronts in the california current system from geostationary satellite observations 1 sea surface temperature sst fronts are determined for the 2001 2004 time period from geostationary operational environmental satellites goes data in the california current system ccs the probability of detecting a sst front at an individual pixel location in the ccs is presented as a bi monthly climatology fronts clearly indicate the seasonal evolution of coastal upwelling as well as meanders and filaments that are often linked with irregularities in coastline geometry winter is characterized by low frontal activity along the entire coast fronts first appear close to the coast during spring particularly south of cape blanco where upwelling favorable winds are already persistent the area of high frontal activity continues to increase during summer especially between monterey bay and cape blanco extending more than 300 km from the coast the region with high frontal activity widens at 2 6 km day 1 off northern baja california a band with persistent fronts is found close to the coast year round but there is no evidence of a seasonal widening of the area of higher activity during fall the weakening of upwelling favorable winds leads to a gradual decrease in frontal activity an empirical orthogonal function eof decomposition reveals the development of sst fronts associated with seasonal upwelling for locations north of monterey bay with less summer intensification to the south the first appearance of fronts close to the coast during spring and the occurrence of the fronts offshore later in the season are represented by additional statistically significant eof modes

equilibrium structure and dynamics of the california current system this paper addresses the structure and dynamical mechanisms of regional and mesoscale physical variability in the subtropical northeast pacific ocean using the regional oceanic modeling system roms the model is configured with a u s west coast domain that spans the california current system ccs with a mesoscale horizontal resolution up to as fine as 3 5 km its mean seasonal forcing is by momentum heat and water fluxes at the surface and adaptive nudging to gyre scale fields at the open water boundaries its equilibrium solutions show realistic mean and seasonal states and vigorous mesoscale eddies fronts and filaments the level of eddy kinetic energy eke in the model is comparable to drifter and altimeter estimates in the solutions with sufficiently fine resolution because the model lacks nonseasonal transient forcing the authors conclude that the dominant mesoscale variability in the ccs is intrinsic rather than transiently forced the primary eddy generation mechanism is the baroclinic instability of upwelling alongshore currents there is progressive movement of meanseasonal currents and eddy energy offshore and downward into the oceanic interior in an annually recurrent cycle the associated offshore eddy heat fluxes provide the principal balance against nearshore cooling by mean ekman transport and upwelling the currents are highly nonuniform along the coast with important influences by capes and ridges in both maintaining mean standing eddies and launching transient filaments and fronts

a process oriented numerical study of currents eddies and meanders in the leeuwin current system abstract while observations provide insight for the basic nature of features in the leeuwin current system lcs process oriented studies are useful for systematically investigating the characteristics and dynamical forcing mechanisms for the currents and eddies in the lcs this process oriented numerical study investigates the roles of wind forcing thermohaline gradients and bottom topography on currents and eddy generation in the lcs with a terrain following primitive equation model in this case the princeton ocean model pom on a beta plane off the western and southwestern coast of australia results show that the lcs is an anomalous eastern boundary current that generates a surface poleward current predominantly over the shelf break an equatorward surface current with upwelling next to the coast in localized regions an equatorward undercurrent and highly energetic mesoscale features such as meanders and eddies thermohaline gradient effects are shown to be the primary mechanism in the generation of a poleward equatorward current undercurrent eddies and meanders in the lcs inshore of the poleward surface flow next to the coast wind forcing plays an important role in generating an equatorward coastal current and upwelling the major role of the wind is to slow the poleward surface flow enhance eddy spin up and create localized upwelling regions such as in the north near shark bay and just north of cape leeuwin bottom topography is shown to be an important mechanism for intensifying and trapping currents near the coast weakening subsurface currents and intensifying eddies off capes the surface poleward current is predominantly steered by the shelf break frequently leaving the coast as it follows the 200 m depth contour southward to cape leeuwin and eastward into the great australian bight overall the results of this process oriented study compare well with available observations in the lcs

application of palynology and petrography in the correlation of the pennsylvanian brazil and staunton formation coals in the eastern part of the illinois basin abstract the coals of the brazil and the lower part of the staunton formations atokan and early desmoinesian pennsylvanian in indiana illinois basin are typically thin and discontinuous as a result both researchers and the industry have experienced problems with coal bed identification and correlation the discrepancies in coal nomenclature and frequent miscorrelations affect coal exploration mine planning and communication between mines and customers our previous study based on exploration boreholes mine scale observations and coal quality and petrographic data from daviess greene and clay counties indiana suggested that the coal mapped as the upper block coal member of clay county might be the same seam as the lower block coal member of daviess county this study is an extension of the previous research conducted farther south to pike warrick and spencer counties indiana in the southern part of indiana correlation of these late atokan and early desmoinesian coal beds is even more difficult because of the absence of well defined marker horizons and limited mining and subsurface well data although palynological and coal petrography data generally correspond these data alone cannot resolve the correlation of the coal beds in this southern region with the coals of clay or greene counties and they must be supplemented with the analysis of associated limestones the ability to accurately identify the perth limestone member which occurs close to the buffaloville coal member of the brazil formation and the holland limestone member which occurs higher up in the staunton formation will help to distinguish between brazil and staunton formation coals

front eddy influence on water column properties phytoplankton community structure and cross shelf exchange of diatom taxa in the shelf slope area off concepcion 36 37 s in eastern boundary current systems ebcss submesoscale to mesocale variability contributes to cross shore exchanges of water properties nutrients and plankton data from a short term summer survey and satellite time series january february 2014 were used to characterize submesoscale variability in oceanographic conditions and phytoplankton distribution across the coastal upwelling and coastal transition zones north of punta lavapie and to explore cross shelf exchanges of diatom taxa a thermo haline front frn 1 flanked by a mesoscale anticyclonic intrathermocline eddy ite 1 or mode water eddy persisted during the study period and the survey was undertaken during a wind relaxation event at the survey time ite 1 contributed to an onshore intrusion of warm oceanic waters southern section and an offshore advection of cold coastal waters northern section with the latter forming a cold high chlorophyll a filament in situ phytoplankton and diatom biomasses were highest at the surface in frn 1 and at the subsurface in ite 1 whereas values in the coastal zone were lower and dominated by smaller cells diatom species typical of the coastal zone and species dominant in oceanic waters were both found in the frn 1 and ite 1 interaction area suggesting that this mixture was the result of both offshore and onshore advection overall front eddy interactions in ebcss could enhance cross shelf exchanges of coastal and oceanic plankton as well as sustain phytoplankton growth in the slope area through localized upward injections of nutrients in the frontal zone combined with ite induced advection and vertical nutrient inputs to the surface layer

a modeling study of the coastal eastern boundary current system off iberia and morocco to investigate the northern canary current system nccs results from four numerical experiments of increasing complexity are examined experiment 1 which uses seasonal wind forcing only shows that as expected wind forcing is the key generative mechanism for the current upwelling meander eddy and filament structures experiments 2 and 3 which have the additional effects of irregular coastline geometry show the following capes are areas for enhanced upwelling extensive filaments maximum current velocities and enhanced growth of cyclonic meanders and eddies an embayment like the gulf of cadiz is a primary region for anticyclonic meander and eddy development the results from the complex flow regime of experiment 4 which has the additional effects of thermohaline gradients and mediterranean outflow highlights the major characteristics and unique features such as the generation of meddies of the nccs with relatively close similarities to field observations

the role of wind stress curl in jet separation at a cape abstract a high resolution numerical model is used to study the importance of spatial variability in the wind forcing to the separation of a coastal upwelling jet at a cape an idealized topography and wind field based on observations from the cape blanco oregon region are used several simulations are investigated with both the intensity and the spatial structure of the wind forcing varied to isolate the importance of the observed intensification in the wind stress and wind stress curl magnitudes to the separation process a simulation using a straight coast confirms that the presence of the cape is crucial for separation wind stress intensification by itself with zero curl does not aid separation the wind stress curl intensification south of the cape on the other hand is important for controlling details of the process because the positive wind stress curl drives upwelling isotherms in the offshore region tilt upward creating a pressure gradient that sustains an intensification of the southw

a real time dynamical forecast of ocean synoptic mesoscale eddies energetic eddy currents are the oceanic analogue of atmospheric weather and have time scales of days to weeks and space scales of tens to hundreds of kilometres1 we have predicted their evolution in time by internal dynamical processes for the forecasts we transferred initialization data from ship to shore based computers during two 2 week periods in june and july of 1983 from an approximately 150 km 2 region in the deep north east pacific off california this is to the best of our knowledge the first such real time forecast at sea the results were substantially successful the dynamics predicted a prominent zonal jet absent in the initial flow also the model forecast revealed a strong eddy merger event otherwise obscured in the data prospects are encouraging for future forecasting which should have important implications for research and practical operations at sea2

the parameterization of subgrid scale heat diffusion in eddy resolved ocean circulation models abstract the two layer quasigeostrophic model of holland is modified to include a parameterization of subgrid scale heat diffusion results from a sequence of simple eddy resolved calculations illustrate the effects of increasing heat diffusivities it is clear that even rather small diffusion coefficients small compared to the viscosity cause important modifications of the eddy field and of the eddy generation process in particular heat diffusion can be very effective at diminishing the baroclinic signal associated with mesoscale processes making it less likely that baroclinic instability processes can exceed damping

palynological correlation of major pennsylvanian middle and upper carboniferous chronostratigraphic boundaries in the illinois and other coal basins

wind driven coastal generation of annual mesoscale eddy activity in the california current abstract two candidate sources for the generation of mesoscale eddy activity in the california current are local baroclinic instability and or the wind stress adjacent to the coast the latter constitutes remote forcing with eddy activity propagating westward from the coast into the california current via rossby wave dynamics in this study two wind driven models are utilized to test the relative significance of these two sources one is an eddy resolving quasigeostrophic qg model with the ability to represent baroclinic instability but not the coastal response to winds the other is a 1 layer primitive equation pe model with the ability to represent the coastal response to winds but not baroclinic instability both models have the same spatial grid i e approximately 20 km and are driven by the same coarse grid wind stress forcing fields over the same one year time period i e january 1987 to december 1987 this period is chosen because of the availability of geosat altimetric sea level obs

two layer model of shear driven coastal upwelling in the presence of bottom topography a stratified two layer fluid is brought to solid body counterclockwise rotation inside a cylindrical tank having a conical bottom with a radial topographic ridge a stress is then applied to the top surface by means of a clockwise differentially rotating disk the resulting ekman layer flux causes the top layer to spin down and the interface to rise near the wall and to descend a t the centre of the tank as this process continues the interface front between the two layers intersects the disk surface and after that migrates away from the wall and allows the bottom fluid to contact the disk directly the migration of the front continues until a steady state is reached the front becomes stationary and the system is in geostrophic balance the first sign of upwelled flow at the surface always occurs as a high speed jet like plume at the bottom topography and only at a later time does a uniform upwelled flow appear a t the surface upstream of the topography this plume which always forms near the downstream edge of the topography migrates in advance of the upstream front to produce an upwelling maximum at the bottom topography the final width of the upstream flow in steady state conditions is estimated by a simple theoretical model which is in good agreement with the experimental results we have an experimental criterion to predict the occurrence of travelling baroclinic waves on the upstream front on the downstream side of the ridge large standing waves are observed with significant upwelling within them under some circumstances cyclones pinch off from the upstream front the plume on the ridge and the crests of the large downstream standing waves we present criteria to predict the occurrence of these pinch off processes

seasonal dynamics of the surface circulation in the southern california current system abstract the seasonal dynamics of the southern california current scc is investigated using a primitive equation ocean model with real coastlines and topography the model is tested with different wind forcing and the resulting flow fields are compared to the mean and seasonal circulation inferred from long term in situ observations california cooperative oceanic fisheries investigation calcofi the model integration forced with the output winds of a regional atmospheric model rsm best captures the statistics of the observed circulation with a 0 9 correlation coefficient for the streamlines and 0 5 for the velocity fields the model integrations reveal a pronounced linear response of the flow field to changes in winds on the shelf region a dynamical feature inferred from calcofi hydrography also suggested in topex ers maps is an annually recurrent westward propagation of ssh anomalies originated in the southern california bight scb during the upwelling season the rsm integration is the only one to capture the correct timing and spatial evolution of this process we therefore use this model integration for guidance in constructing a dynamical framework to interpret the observed circulation and its variability during the upwelling season in spring there is an upward tilt of the isopycnals along the coast directly forced by the winds in the bight as the spring transitions to the summer the upwelling winds relax in the bight but are still strong in the region offshore approximately in correspondence of the continental slope positive wind stress curl condition anomalous denser waters in the location of the southern california eddy are maintained and reinforced by the combined interaction of the coastal islands geometry and the wind stress curl through ekman dynamics the adjustment process to the denser water initiates a westward propagation of ocean density anomaly through rossby waves and reinforces the cyclonic gyre like circulation of the sce increasing positive vorticity surface poleward flow maintained by the positive wind stress curl is also reinforced in proximity of point conception as a consequence of the adjustment during the summer the cyclonic gyre becomes increasingly unstable as the core of the ocean anomalies crosses the continental slope instability processes within the cyclonic region characterized by a sharp increase in eke shed eddies that leave the region either drifting to the west or interacting with existing eddies in the region offshore the eke reaches a seasonal maximum at the end the summer in the cyclonic region and in late fall further offshore where the eddies are fully developed the shedding of eddies cannot be directly seen in the calcofi observations because of the sampling aliasing for this point we rely on the strong suggestion of the model which we assume is able to capture the leading order dynamics additional integrations with a linearized version of the model are also presented to reinforce our interpretation of the westward propagation of the isopycnal anomalous displacement associated with rossby wave dynamics

seasonal variability of alongshore geostrophic velocity off central california seasonal variability of alongshore geostrophic velocity relative to 500 dbar is examined from 23 years of hydrographic data along two sections off central california one off point sur and the other off point conception the seasonal cycles are determined by least square fits of the gappy data records to harmonics with annual and semiannual periods attention is focused on variability over the outer continental slope geostrophic flow in the upper 100 m along both sections is coherent and predominantly annual with equatorward flow from february to september and poleward flow from october to january the flow deeper than 100 m is distinctly different along the two sections the nearshore deep flow is predominantly semiannual off point conception notably different from surface flow and poleward all year with maxima in december and june this semiannual variability at depth is a prevalent feature of the california current system the nearshore deep flow off point sur is unusual in that it is predominantly annual with maximum poleward flow in december and weak equatorward flow from march to may the seasonal variations over the continental slope compare favorably with existing models of eastern boundary current systems in two respects 1 the surface flow leads the predominantly annual wind forcing in this region by about one month and 2 the deep poleward counterflow is coherent with the local poleward barotropic pressure gradient at both locations with a phase lag of approximately 2 months however contrary to the results of existing dynamical models the semiannual poleward pressure gradient and undercurrent off point conception appear to be unrelated to the wind forcing which is predominantly annual in this region these semiannual variations are highly coupled to the semiannual flow throughout the water column inside the southern california bight suggesting that they may be topographically generated

summer upwelling and thermal fronts in the northwestern south china sea observational analysis of two mesoscale mapping surveys persistent coastal upwelling and upwelling induced thermal fronts in the northwestern south china sea are investigated using satellite measurements two intensive mesoscale mapping surveys and three bottom mounted adcps the results indicate that pronounced surface cooling and upwelling related fronts with a width of 20 50 km occur around hainan island and persist through the summer upwelling season driven by the prevailing southwesterly monsoon the subsurface cooling band is approximate to 6 degrees c colder than the water offshore of the east coast where the thermal gradients are generally more than 0 1 degrees c km the cold and nutrient rich coastal water is identified to be derived primarily from the deep water of the outer shelf at the same time the spatial structure of the upwelling and thermal front as well as the upwelling related coastal currents is significantly regulated by wind forcing a prominent lagged correlation between the moored temperature records and alongshore wind stress is detected in the east coast the correlation coefficient is 0 8 with the temperature lagging behind wind stress by 2 2 days indicating that the cooling band off the east coast is dominated mostly by the alongshore southwesterly monsoon during the upwelling season

oceanic variability off the central california coast abstract mesoscale variability off the central california coast is strongly influenced by coastal upwelling and related processes off point sur there is significant space time variability in oceanic properties over periods of days and distances of several tens of km however the internal density field averaged over space ca 120km alongshore and time ca 18 days reveals the expected characteristics of a coastal upwelling regime including an equatorward surface jet 25km to 40km offshore and weaker poleward flow below 150m and within 20km of the coast upper ocean circulation is strongly influenced by the bathymetry offshore to water depths of at least 1000m based on repeated horizontal grids of oceanographic stations horizontal correlation scales for temperature are of the order of 30km in the upper 100m hence a horizontal sampling rate of ca 10km is desirable vertical correlation scales for temperature are of the order of 100m hence a vertical sampling rate of ca 10m is desirable similarly there are indications of a temporal correlation scale of a few weeks hence a temporal sampling rate of ca a few days is desirable empirical orthogonal functions eofs in the cross shore vertical plane suggest the influence of coastally trapped motions within 40km of the coast with an intense alongshore near surface transient coastal jet located ca 20km offshore sudden spring transitions to coastal upwelling conditions are often pronounced in coastal temperature records and they may precede the offshore migration of the major upwelling front by at least a month or more the spring transitions occur over a period of about a week in 1980 the spring transition propagated poleward along the california coast at a speed of ca 64km d 1 during spring and summer movement of a coastal upwelling front often located between 15km and 50km offshore is a major contributor to cross shore variability the upwelling front meanders with an alongshore scale of about 80km a time scale of 30 to 40 days and an amplitude scale of 10km rms based on satellite infrared ir imagery the along shore mean position of the major upwelling front migrates offshore during spring and summer offshore displacement of the front may be caused by ekman transport over periods of days to weeks and by rossby wave dispersion over longer periods during summer a time dependent offshore scale based on rossby wave dynamics was more appropriate than the baroclinic rossby radius every three to four years during 1971 through 1984 el nino episodes produced interannual variability in coastal sea surface temperature sst off central california most of the warming occured during fall and winter el nino episodes were often followed by major spring transitions the recent 1982 1983 episode was 2 to 3 c warmer than the three previous episodes over the past 14 years and its influence lasted almost twice as long

mesoscale variability in current meter measurements in the california current system off northern california current meter data from a triad of moorings located on the continental rise offshore of point reyes point arena and from a mooring site located about 250 km offshore and to the northwest of the array are analyzed the continental rise moorings were deployed from october 1984 to july 1985 and each had five meters at depths from about 150 to about 3560 m the offshore mooring was deployed from september 1982 to august 1983 with six meters positioned from about 150 to 3800 m velocity components were highly vertically coherent in the upper 600 m and were in phase for periods longer than about 10 days temperature tended to be less coherent there was some horizontal coherence in the continental rise array coherence at 9 13 days between the deep temperature t at about 3200 m measurements at m1 and m2 located about 120 km offshore and separated by about 100 km coincided with very high in phase coherence in the northward velocity component v although there was no coherence between the first baroclinic modal components at m1 and m2 the eastward barotropic velocity component was coherent at periods of 9 11 days and the northward barotropic velocity component was coherent at 8 15 days and 4 5 6 days the triad provided a complete data set only at 350 m the highest coherence was between out of phase v components and also t at m2 and m3 about 100 km seaward of m2 at periods of 45 90 days with the dominant time domain empirical orthogonal function eof representing strong horizontal shear between m2 and m3 at periods of 9 13 days there was bottom and surface intensification in the nearshore kinetic energy spectra suggestive of a superposition of a barotropic mode with the first two baroclinic modes and partially consistent with the presence of topographic rossby waves the vertical structure at m2 differed from that at w10 the offshore mooring where the deep about 3000 m flow tended to be stronger than that near the continental slope and rotary behavior was apparent at 3000 m the barotropic modal energy was higher at w10 than at m2 but the first baroclinic modal energy was comparable at the two sites at m2 when they were coherent the barotropic and first baroclinic modes enhanced each other in the upper water column and led to reduced flow at deeper levels at w10 these modes were mainly out of phase and so enhanced the flow at deeper levels these differences which may be spatial rather than temporal increase the complications of initialization of predictive models from mass field data alone there are some indications of current and temperature variability due to fluctuating winds for example the northward components of wind stress and barotropic current were coherent at all locations at periods of 8 9 days at w10 there was also coherence between the eastward components of barotropic current and wind stress at 16 19 days on the basis of frequency domain eofs some of the current variability was forced by large scale i e about 1000 km wind stress at periods of between 5 and 10 days however less than half the current variability was demonstrably related to the wind stress at m2 and m3 at 150 m large amplitude about 1 c temperature variations which are sustained for several weeks are influenced by alongshore flow convergence and offshore jets coherence between t at 350 m and wind stress curl is suggestive of ekman pumping at m3 but the temperature was also related to alongshore convergence and offshore flow

coastal trapped waves alongshore pressure gradients and the california undercurrent abstractthe california undercurrent cuc a poleward flowing feature over the continental slope is a key transport pathway along the west coast of north america and an important component of regional upwelling dynamics this study examines the poleward undercurrent and alongshore pressure gradients in the northern california current system ccs where local wind stress forcing is relatively weak the dynamics of the undercurrent are compared in the primitive equation navy coastal ocean model and a linear coastal trapped wave model both models are validated using hydrographic data and current meter observations in the core of the undercurrent in the northern ccs in the linear model variability in the predominantly equatorward wind stress along the u s west coast produces episodic reversals to poleward flow over the northern ccs slope during summer however reproducing the persistence of the undercurrent during late summer requires additional incoming energy from sea level variability applied south

modeling studies of the leeuwin current off western and southern australia the leeuwin current strengthens considerably from february to may each year following the slackening of southerly coastal winds strong eddies develop a high resolution multilevel primitive equation ocean model is used to examine this eddy development in an idealized way by considering the development of flow from rest when temperatures are initially given the observed longshore gradients the system is allowed to geostrophically adjust in the absence of longshore winds and of any surface heat flux two types of experiments are conducted the first type uses the indian ocean climatological temperature gradient forcing case 1 and 2 while the second type repeats the first experiment with the added contribution of the north west shelf nws temperature profile cases 3 and 4 to investigate the additional effects of coastline irregularities cases 1 and 3 use an ideal coastline while cases 2 and 4 use an irregular realistic coastline in all cases maximum surface velocities occur at cape leeuwin where the leeuwin current changes direction and off southern australia maximum undercurrent velocities occur off western australia in case 1 cape leeuwin and the western australian coast are the preferred locations for the development of warm anticyclonic eddies which are generated due to a mixed instability mechanism in case 2 the warm anticyclonic eddies occur in the vicinity of coastal promontories and at cape leeuwin while advection of warm water is present along the entire coast in case 1 the irregular coastline geometry limits the extent of warm water in case 2 the added contribution from the nws water in cases 3 and 4 augments the onshore geostrophic inflow to produce a model leeuwin current and undercurrent that are more vigorous and unstable than in the previous cases in case 3 the nws water adds strong horizontal shear to the coastal equatorial region of the domain and vertical shear to the inshore current it also advects warmer water along the entire coast in case 4 the addition of both the nws water and the irregular coastline results in the establishment of a stronger surface current and undercurrent than in the previous cases however the irregular coastline limits the extent of the advection of the nws warmer water along the australian coast in all cases warm anticyclonic eddies develop at the coast cold cyclonic eddies form from the limbs of the established warm anticyclonic eddies with the result that two counterrotating cells are developed once the eddy pairs begin their westward propagation the leeuwin current intensifies as nonlinear effects result in a jet between the eddies and the coast these effects translate downstream to augment the current velocities at the coast which due to a mixed instability mechanism result in the development of new anticyclonic eddies at the coast the results from case 4 which has the most realistic features highlights the major characteristics of the leeuwin current and agrees well with available observations these results show that the model successfully captures the qualitative nature of the nonlinear eddying response of the leeuwin current

variability of the near surface eddy kinetic energy in the california current based on altimetric drifter and moored current data low pass filtered velocities obtained from world ocean circulation experiment woce surface drifters deployed in the california current off northern california during 1993 1995 have been compared with surface geostrophic velocity estimates made along subtracks of the topex poseidon altimeter and with moored acoustic doppler current profiler adcp data to obtain absolute geostrophic velocities a mean sea surface height ssh field was estimated using the mean drifter velocities and historical hydrographic data and was added to the altimetric ssh anomalies the correlation between collocated drifter and altimetric velocities is 0 73 significant at the 95 level the component of the drifter velocity which was uncorrelated with the altimetric velocity was correlated with the wind in the ekman transport sense monthly averages of eddy kinetic energy eke estimated using all drifter and altimeter data within the domain 124 132 w 33 40 5 n show energy levels for the drifters that are about 13 greater than those for the altimeter drifter altimeter and adcp measurements all exhibit similar seasonal cycles in eke with the altimeter data reaching maximum values of about 0 03 m 2 s 2 in late summer fall wavenumber spectra of the altimeter velocity indicate that the velocity fluctuations were dominated by features with wavelengths of 240 370 km while the adcp data suggest that the temporal scales of these fluctuations are at least several months between 36 and 40 5 n the region of monthly maximum eke migrates westward to about 128 w on a seasonal timescale this region of maximum eke coincides with the maximum zonal ssh gradient with increased eke associated with increased southward flow a simple model shows that much of the seasonal cycle of the ssh anomalies can be produced by linear processes forced by the curl of the wind stress although the model cannot explain the offshore movement of the front

aspects of the mean wintertime circulation along australia s southern shelves numerical studies abstract a high resolution numerical model is used to study the mean wintertime shelf slope circulation between the gulfs of south australia and the west coast of tasmania the mean downwelling favorable winds for the region result in a continuous eastward coastal current cc extending from cape leeuwin to the eastern coast of tasmania the magnitude of the cc is generally largest over the shelf break has speeds of more than 40 cm s 1 transport 2 4 sv sv 106 m3 s 1 and is generally in good agreement with observations the relative importance of the leeuwin current zonal winds and density gradients to the shelf circulation is established within bass strait the eastward circulation is in good agreement with observations and simple models show that about 30 of the transport arises from local winds and the remainder from the cc the total transport through the strait 0 95 sv is shown to be controlled by sea level on the east coast of tasmania a current of up to 10 cm s 1 is also found to flow

circulation and energetics of a model of the california current system abstract data from an eight layer fnoc wind driven eddy resolving limited area quasi geostrophic numerical model have been used to study the dynamics of the california current system ccs with particular emphasis on the energetics the model includes quasi realistic bottom topography and the true coastline and is embedded in a coarser resolution model occupying almost all of the north pacific ocean the model simulates the main components of the ccs such as the california current cc the davidson current the california undercurrent and the southern california eddy the simulated cc is both an active eddy mean flow interaction area and an effective wave source for the north pacific ocean making use of the mean potential vorticity field of the different layers four different regimes are described for the mean circulation inertial intermediate beta and bottom topographic overall the new surface circulation is energetically dominated by the mean flow whereas the deep simulation is ener