spatio temporal variability in suspended particulate matter concentration and the role of aggregation on size distribution in a coral reef lagoon this paper presents the concentration and size distribution of suspended particles in the south west coral reef lagoon of the island of new caledonia data are provided by filtration techniques optical backscattering obs measurements and in situ laser diffraction particle sizing the concentration of suspended particles increased from reef to land a bottom nepheloid layer occurred over the entire lagoon and was more distinct on the nearshore area small particles were more abundant in the bottom nepheloid layer than in the overlying water column the concentration of suspended particles showed more variability over space than over time conversely the particle size distribution of suspended particles showed more variability at a given location over a month time variability than at a given moment over the lagoon space variability analysis showed that aggregates represented a large fraction of suspended particles microscope visualization and chemical analysis of a sample suggest the inclusion of a transparent exopolymeric matrix the relative abundance of aggregates over suspended particle volume concentration was found to increase as the quantity of suspended particle decreased the spatial distribution of the relative abundance of aggregates suggests more aggregates proximal to coral reefs the high concentration of aggregates at low turbidity and the spatial distribution of the relative abundance infer that aggregation is induced by the presence of organic ligands unlike optical backscattering and light attenuation measurements that are size sensitive measurements of suspended particle concentration in situ laser diffraction particle sizing provides a relevant optical measurement of suspended particulate matter in such an aggregate dominated system

optical backscattering by particles in arctic seawater and relationships to particle mass concentration size distribution and bulk composition the magnitude and spectral shape of the optical backscattering coefficient of particles b bp lambda is being increasingly used to infer information about the particles present in seawater relationships between b bp and particle properties in the arctic are poorly documented and may differ from other oceanic regions which contribute the majority of data used to develop and parameterize optical models we utilize recent field measurements from the chukchi and beaufort seas to examine relationships between the spectral backscattering coefficient of particles in seawater and the mass concentration bulk composition and size distribution of the suspended particle assemblage the particle backscattering coefficient spanned six orders of magnitude from the relatively clear waters of the beaufort sea to extremely turbid waters on the mackenzie shelf this coefficient was highly correlated with the mass concentration of particles and to a lesser extent with other measures of concentration such as particulate organic carbon or chlorophyll a increased backscattering and high mass specific b bp lambda was associated with mineral rich assemblages that tended to exhibit steeper size distributions while reduced backscattering was associated with organic dominated assemblages having a greater contribution of large particles our results suggest that algorithms which employ composition specific relationships can lead to improved estimates of particle mass concentration from backscattering measurements in contrast to theoretical models however we observe no clear relationship between the spectral slope of b bp lambda and the slope of the particle size distribution in this environment

observed evolution of tropical deep convective events and their environment abstract using a compositing technique the temporal progression of tropical convective systems and the mean atmospheric state in their vicinity is constructed from a time series of geostationary satellite and operational rawinsonde data the technique establishes the stage in the life cycle of convection prevailing at a given place and time by a simple objective method using time series of satellite brightness temperature tb histograms collected from a region surrounding the site soundings are classified according to their placement in the convective life cycle and composites formed that represent the areal mean state of the convecting atmosphere at each stage for several scales of horizontal averaging the temporal structure found here for the mesoscale mean atmosphere closely resembles existing observations of the horizontal structure of a tropical squall line albeit with certain reductions in amplitude and stabilization rate this supports the generality of previous findings that the physical m

stochastic parameterization of convective area fractions with a multicloud model inferred from observational data abstractobservational data of rainfall from a rain radar in darwin australia are combined with data defining the large scale dynamic and thermodynamic state of the atmosphere around darwin to develop a multicloud model based on a stochastic method using conditional markov chains the authors assign the radar data to clear sky moderate congestus strong congestus deep convective or stratiform clouds and estimate transition probabilities used by markov chains that switch between the cloud types and yield cloud type area fractions cross correlation analysis shows that the mean vertical velocity is an important indicator of deep convection further it is shown that if conditioned on the mean vertical velocity the markov chains produce fractions comparable to the observations the stochastic nature of the approach turns out to be essential for the correct production of area fractions the stochastic multicloud model can easily be coupled to existing moist convection parameterization schemes used in ge

instruments for particle size and settling velocity observations in sediment transport in this paper we describe two sensors for measurement of particle size distribution and settling velocity distribution these measurements are critical to the correct estimation of the true sediment concentration in the field as well as to evaluating models for transport rates of sediments a multi angle measurement of laser scattering is made and inverted to obtain the particle size distribution since small angle scattering is relatively insensitive to particle composition the size distribution measurements are robust and do not require particle refractive index it is shown that with a knowledge of the size distribution true particulate volume concentration can be obtained unaffected in calibration by changes in particle size distribution the data from bottom boundary layer experiments using the instrument show the presence of temporal variability in size distribution associated with the strength of forcing of the boundary layer the importance of these observations lies in the implication that historical data acquired with single parameter optical or other sensors needs to be revisited in the second instrument analyzing the observation of size distributions during settling in a settling column produces settling velocity estimates in this case the history of concentration of each size class is examined to determine the settling velocity without invoking any assumptions of settling regime settling velocity data from a field experiment off the new jersey coast fit the model wf na 0 45 10 23 a 1 2 n

on the vorticity balance over steep slopes kuroshio intrusions northeast of taiwan abstractthe circulation of the kuroshio northeast of taiwan is characterized by a large anticyclonic loop of surface intrusion and strong upwelling at the shelfbreak to study the mechanisms of kur

the vertical profile of radar reflectivity of convective cells a strong indicator of storm intensity and lightning probability abstract reflectivity data from doppler radars are used to construct vertical profiles of radar reflectivity vprr of convective cells in mesoscale convective systems mcss in three different environmental regimes the national center for atmospheric research cp 3 and cp 4 radars are used to calculate median vprr for mcss in the oklahoma kansas preliminary regional experiment for storm central in 1985 the national oceanic and atmospheric administration tropical ocean global atmosphere radar in darwin australia is used to calculate vprr for mcss observed both in oceanic monsoon regimes and in continental break period regimes during the wet seasons of 1987 88 and 1988 89 the midlatitude and tropical continental vprrs both exhibit maximum reflectivity somewhat above the surface and have a gradual decrease in reflectivity with height above the freezing level in sharp contrast the tropical oceanic profile has a maximum reflectivity at the lowest level and a very rapid decrease in reflectivity with he

the influence of shelf sea fronts on winter monsoon over east china sea strong sea surface temperature fronts in open seas are known to affect the atmosphere shelf sea fronts in winter have comparable strengths yet their impacts on winds have not been studied in january of 2012 a persistent narrow band of cloud stretching 600 1 000 km was observed along the front of east china sea ecs numerical and analytical models show that the cloud was formed atop a recirculating cell induced by the front and more generally that plumes of low and high pressures emanate and spread far from fronts consistent with the theory observations show that in ecs at inter annual time scales strong fronts co vary with on shelf convergent wind strong northeasterly monsoon and alongshelf alignment of clouds with low clouds near the coast and higher clouds offshore our results suggest that shelf sea fronts are potentially an important dynamic determinant of climate variability of east asia

seasonal exchanges of the kuroshio and shelf waters and their impacts on the shelf currents of the east china sea previous in situ observations and modeling studies have indicated that through mass and momentum exchanges across the shelf edge the kuroshio can significantly influence the shelf currents of the east china sea ecs here instead of localized observations this study uses 25yr of drifter data supported by satellite and other data to identify seasonal cross shelf exchanges along the entire shelf edge the authors show that kuroshiomeandersonshorefromfalltowinterandoffshorefromspringtosummer withthelargestamplitude northeast of taiwan the influence is limited to the shelf edge when the kuroshio meanders offshore in spring and summer by contrast strong onshelf intrusions and cross shelf exchanges occur when the kuroshio meanders onshore in fall and winter drifters intrude onshelf northeast of taiwan and spread as far north as 308n against the strong northeasterly wind the forcing on the shelf is identified as a northward downsloping of the sea level that is steepest north of taiwan at 258 288n but which is 3 times weaker farther north the vorticity budget computed from a numerical model indicates that intrusion during fall andwinter is primarily a result of balancebetweenonshelfadvectionofambientpotentialvorticityandvorticityproductionbythealong isobath pressure gradient acting on the changing mass of water column across the continental slope

a numerical study on the formation of upwelling off northeast taiwan 1 we examined the spatial and temporal variations of upwelling off northeast taiwan using a fine resolution numerical model with realistic bathymetry the zonally running shelf break in the area deflects the kuroshio seaward and produces upwelling on its on shelf edge the upwelling in turn manifests a cold dome or a cyclonic eddy in depths below 150 m or so the upwelling and hence the cyclonic eddy exist year round above this depth the eddy waxes and wanes as the upper portion of the kuroshio migrates seaward and shoreward respectively the eddy event fluctuates in a wide range of timescales seasonally the occurrence heavily favors summer rather than winter because the mean kuroshio axis migrates seaward in summer intraseasonally the fluctuation contains two dominant periods centered at 70 days and 30 days local wind forcing and channeling by two local canyons do not affect the eddy statistics significantly

a laboratory evaluation of the laser in situ scattering and transmissometery instrument using natural sediments abstract the lisst laser in situ scattering and transmissometery instrument was designed by sequoia scientific to measure the particle size distributions and concentrations of sediment suspensions in the field environment to understand the lisst s performance with natural sediments from a variety of marine sources several experiments were performed to compare the lisst s results to traditional sieving filtering and weighing techniques the lisst was able to correctly locate the peak of a unimodal particle size distribution and resolve the two peaks of a bimodal distribution if they are separated by at least 1 for sediment sizes of 5 to 250 m unlike a single frequency scattering sensor for sediment concentration which require sediment size specific calibration constants the lisst is able to accurately measure sediment concentration with a single calibration constant for varying size distributions within the size range of 5 to 250 m the lisst was also found to adequately represent the particle volumetric size distribution for two different samples from marine environments

the statistical characteristics of convective cells in a monsoon regime darwin northern australia abstract a season of operational cell and track data from darwin australia has been analyzed to explore the statistical characteristics of the convective cell heights the statistics for the monsoon and break regimes are significantly different with the break season cells being higher for a given reflectivity threshold the monsoon cells produce more rain but there are fewer intense cells and there is a much larger contribution from stratiform rain the monsoon cells are also slightly larger but shorter lived than the breaks the shorter lifetime may reflect a more rapid transition to a longer lived stratiform character the monsoon regime is shown to be associated with large scale ascent and higher humidity that may lead to more frequent but weaker cells within regimes the subset of intense cells generally reach near the tropopause or overshoot however there is little evidence in the data for a multimodal distribution of cell heights except perhaps for the intense monsoon cases instead the pi

continental slope flow northeast of taiwan abstract hydrographic observations and current measurements with a shipboard acoustic doppler current profiler over the continental shelf slope junction northeast of taiwan during 10 17 august 1994 allow the construction of the mesoscale flow pattern generated by the collision of the kuroshio and a stretch of the continental shelf that has turned to run nearly east west the pattern is made up of a deflected kuroshio mainstream to the east an intrusion of kuroshio water onto the continental shelf region a counterclockwise circulation over mien hwa canyon mhc immediately northeast of taiwan a deep southwestward countercurrent along the northern wall of mhc and a seaward outflow of continental shelf water around the northern coast of taiwan the hydrography features a cold dome over the west side of mhc that consisted of subsurface kuroshio water a temperature salinity plot of all the station data shows the incorporation in the neighborhood of taiwan of continental shelf water into the kuroshio

statistical characteristics of convective clouds over the western ghats derived from weather radar observations x band radar observations at mandhardev 18 04 n 73 85 e are used to investigate statistics of convective clouds over the western ghats during monsoon season june september 2014 convective storms cells are identified using an objective tracking method to examine their spatio temporal variability thus quantifying the time continuous aspects of convective cloud population over the region for the first time an increased frequency of storm location and initiation along the windward mountains compared to coastal and lee side highlights orographic response to southwesterly flow with superimposed diurnal cycle an eastward progression of convective activity from upstream the barrier through windward slopes of mountains over to the lee side is observed storm area height and duration follow lognormal distributions wherein small sized storms contribute more to total population and unimodal distribution of 35 dbz top heights peaking at 5 5 km depicts the dominance of shallow convection storms exhibit a pronounced diurnal cycle with a peak in afternoon hours while the convective area maximum is delayed by several hours to that of precipitation flux cell lifetime and propagation show that cells move with slow speeds and have mean duration of 46 minutes they align east west nearly parallel to mountain ridges and their direction of movement is steered mostly by large scale winds at lower levels based on top heights convective cells are further classified into cumulus congestus and deep clouds in general congestus deep cells are most abundant in the windward leeward side a lead lag relationship between congestus and deep cells indicates midtroposphere moistening by congestus cells prior to deep convection

the fraser gyre a cyclonic eddy off the coast of eastern australia this paper examines the on shelf circulation of the eastern australian continental shelf for a region off southeast queensland we identify a characteristic seasonally reoccurring wind driven cyclonic flow it influences the cross shelf exchange with the east australian current eac which is the western boundary current of the south pacific ocean we refer to this cyclonic circulation as the fraser gyre it is located south of fraser island between about 25 s and 27 s the region is adjacent to the intensification zone of the eac where the current accelerates and establishes a swift albeit seasonally variable southward boundary flow through the analysis of several data sets including remotely sensed sea surface temperature and sea surface height anomaly satellite tracked surface drifters ocean and atmospheric reanalysis data as well as geostrophic currents from altimetry we find that the on shelf fraser gyre develops during the southern hemisphere autumn and winter months the gyre is associated with a longshore near coast northward flow maximum northward on shelf depth averaged velocities are estimated with about 0 15 0 26 ms 1 the flow turns eastward just to the south of fraser island and joins the persistent southward eac flow along the shelf break the annual mean net cross shelf outward and inward flow associated with the gyre is about 1 17 0 23 sv in the north and 0 23 0 13 sv 1 sv 106 m3s 1 in the south mean seasonal water renewal time scales of the continental shelf are longest during austral winter with an average of about 3 3 days due to the fraser gyre retaining water over the shelf however monthly estimates range from 2 to 8 days with the longer timescale during the austral autumn and winter the southerly wind during austral autumn and winter is identified as controlling the on shelf circulation and is the principal driver of the seasonally appearing fraser gyre the conceptual model of the fraser gyre is consistent with general physical principals of the coastal shelf circulation a southerly wind is associated with surface layer flow toward the coast a near coast positive ssha with a current in the direction of the wind down welling and export of shelf water the fraser gyre influenced cross shelf exchanges are possibly facilitating the offshore transport of fish larvae sediments nutrients river discharges and other properties across the shelf break and into the southward flowing eac during the austral autumn and winter

interannual variability of the kuroshio onshore intrusion along the east china sea shelf break effect of the kuroshio volume transport the interannual variability of the kuroshio onshore intrusion koi across the east china sea ecs shelf break and its response to the ecs kuroshio volume transport kvt during 1993 approximate to 2010 are studied based on a high resolution real time and global ocean general circulation model since variability of kvt is mainly determined in the interior pacific it is rather a remote than a local factor for the local ecs koi on interannual time scales kvt affects koi not only in the net volume transport across the entire shelf break but also in the spatial pattern along the shelf break when kvt increases the intrusion decreases increases upstream downstream of the major intrusion region northeast of taiwan the retreating increases decreases upstream downstream of the main veering region southwest of kyushu these patterns are caused by cyclonic eddies induced by the seaward deflection of the kuroshio axis from the shelf break which ultimately results from the kvt increase a diagnostic mechanism of koi approximate to msin delta h 1 is proposed where h is the bottom depth is the angle between isobaths and the vertically averaged current and m is the absolute volume transport at the shelf break is large in the major intrusion retreating regions and stable on interannual time scales while m changes with opposite signs between upstream and downstream of the major intrusion retreating regions the mechanism explains well the relation of local kvt and the spatial pattern of koi along the shelf break in both the mean state and the interannual variations

the four cumulus cloud modes and their progression during rainfall events a c band polarimetric radar perspective 1 there is no objective definition to separate cumulus congestus clouds from the shallow cumulus and deep clouds this has generated misinterpretation about the role of congestus clouds to promote deep convection through the potential of moistening the middle troposphere in this study an objective identification for the different tropical cumulus modes is found by examining the occurrence frequency of the cloud cell top heights cths and near ground at 2 5 km height rainfall properties of these cells using a three season database of the darwin c band polarimetric radar four cumulus modes were identified namely a shallow cumulus mode with cth in the trade inversion layer 1 3 km a congestus mode with tops in the highly stable middle troposphere 3 6 5 km a deep convective mode with tops in the region of free convection 6 5 15 km and an overshooting convection mode with tops in the tropical tropopause layer cth 15 km the study also investigates the connections between these cumulus modes during heavy rainfall events the congestus mode occurs predominantly from 10 h prior to the peak rainfall event to 2 h past the event the deep cloud populations modes 3 and 4 have their maxima at and shortly after the time of the rainfall peak with maximum occurrence just below the tropical tropopause layer a comparison of the heavy rainfall events occurring in morning oceanic conditions against the afternoon continental conditions revealed a higher ratio of the shallow to the deep cloud population and a shorter transition time from the shallow to the onset of deep population in the morning oceanic conditions than the afternoon land conditions it is also found through the analysis of the large scale moisture budget data set that for both the morning and afternoon events the moistening peaked before the peak in the congestus populations

two faces of enso induced surface waves during the tropical cyclone season abstract the response of the wave climate to tropical cyclones tcs is investigated using the significant wave height swh observed from satellites and the wavewatch iii ww3 model tropical cyclone wind generates local waves wind seas under the tc and longer period waves swells that propagate long distances the genesis location intensity and frequency of tropical cyclones over the global ocean are strongly affected by the phases of the el nino southern oscillation enso it is shown that the interannual variation of global ocean surface waves in the subtropics during summer is dominated by enso related tc activity in particular in the subtropical western north pacific the wind power is stronger in the tc season before an el nino and weaker before a la nina these enso related tc variations are shown through composite and empirical orthogonal function analyses as well as modeling to dominate the spatial distribution and temporal variation of the swh over the western north pacific the model confirms that longer period waves swells are driven into northern south china sea toward japan in mid latitudes and toward the central pacific along the equator due to enso related tc activities the wind power and swh over the subtropical western north pacific lead and regress well with the enso index suggesting that they may potentially serve as useful enso predictors

sedimentary responses to the cross shelf transport of terrigenous material on the east china sea continental shelf sedimentary responses to the cross shelf transport on the east china sea continental shelf are ascertained based on analyses of the sediment grain size and detrital mineral components of surficial sediments sedimentological data show that fine grained sediments can be transported across the continental shelf and have formed a tongue shaped zone with an axis located near 29 degrees n that extends from the coast to 124 degrees 40 e or beyond the sediments in this tongue shaped zone are rich in very fine silt and day as are the dominant sediment fractions discharged by the modern yangtze river indicating a modem terrigenous source sediment with grain sizes 7 9 phi is the main fraction that is transported across the continental shelf in contrast to the regions in the same longitude in the tongue shaped zone the relatively low heavy mineral content high schistose mineral content and high dolomite content and the mixture of fresh and weathered minerals show that modern yangtze river sediment has been widely transported to this region meanwhile the simultaneous existence of the fine grained tongue and a coarse grained area immediately south of the base of the tongue coincident with the nearshore kuroshio branch current intrusion area indicate that the kuroshio intrusion plays an important role in triggering the cross shelf flows c 2019 elsevier b v all rights reserved

the onset of convection in the madden julian oscillation abstract an observational study of the onset of convection in the madden julian oscillation mjo was performed composites of radiosonde data from the comprehensive aerological reference data set were constructed for an ensemble of tropical stations located in the indian ocean maritime continent and western pacific ocean the composites suggest that for the off equatorial stations used in this study the mjo period may be set by the buildup and discharge of the low level moist static energy this result supports the discharge recharge hypothesis of blade and hartmann mjo events appear to begin when the off equatorial atmosphere has been destabilized through a combination of low level moist static energy buildup and concurrent drying of the middle troposphere by subsidence in the wake of the previous cycle of mjo convection the low level moist static energy buildup is controlled by a corresponding increase in low level moisture the increase in low level moisture is not caused by the 1000 mb convergen

contrasting inherent optical properties and particle characteristics between an under ice phytoplankton bloom and open water in the chukchi sea abstract variability in the inherent optical properties iops of seawater and characteristics of the particle assemblage were examined along a transect in the chukchi sea during july 2011 this transect encompassed samples from open waters of the marginal ice zone exhibiting low concentrations of chlorophyll a chl a 3 as well as an extensive phytoplankton bloom chl a 30 mg m 3 beneath consolidated pack ice measurements included the spectral coefficients for particulate beam attenuation backscattering and absorption bulk indicators of particle concentration and composition and the particle size distribution within the bloom microphytoplankton contributed 95 to the total chl a and relatively small amounts of nonalgal particles were present this assemblage exhibited low chl a specific phytoplankton absorption coefficients 0 006 m 2 mg 1 at 676 nm indicating a strong influence of pigment packaging and a weak spectral dependence of the particulate backscattering coefficient in contrast the phytoplankton community in nutrient depleted surface waters outside the sea ice had a strong contribution of picoplankton to chl a 54 and an increased abundance of nonalgal particles the chl a specific phytoplankton absorption coefficient approached maximum values at 676 nm 0 023 m 2 mg 1 and particle backscattering had much stronger spectral dependence additional samples from near the sea floor exhibited characteristics of either mineral dominated assemblages or a mixture of mineral and organic particles and also displayed optical differentiation from the surface samples the marked contrast in absorption attenuation and backscattering properties of these ecological regimes suggest that they can be discriminated from optical measurements available on a variety of in situ and remote sensing platforms

when will the summer arctic be nearly sea ice free 1 the observed rapid loss of thick multiyear sea ice over the last 7 years and the september 2012 arctic sea ice extent reduction of 49 relative to the 1979 2000 climatology are inconsistent with projections of a nearly sea ice free summer arctic from model estimates of 2070 and beyond made just a few years ago three recent approaches to predictions in the scientific literature are as follows 1 extrapolation of sea ice volume data 2 assuming several more rapid loss events such as 2007 and 2012 and 3 climate model projections time horizons for a nearly sea ice free summer for these three approaches are roughly 2020 or earlier 2030 10 years and 2040 or later loss estimates from models are based on a subset of the most rapid ensemble members it is not possible to clearly choose one approach over another as this depends on the relative weights given to data versus models observations and citations support the conclusion that most global climate model results in the cmip5 archive are too conservative in their sea ice projections recent data and expert opinion should be considered in addition to model results to advance the very likely timing for future sea ice loss to the first half of the 21st century with a possibility of major loss within a decade or two

the influence of the ocean on typhoon nuri 2008 abstracttyphoon nuri 2008 was 1 of approximately 120 typhoons in the past 60 years that passed through a narrow gap the luzon strait connecting the western north pacific and the south china sea scs in total 70 of these storms including nuri reached their maximum intensities over the warm waters east of luzon and in the kuroshio then rapidly weakened in the scs numerical experiments were conducted to understand the intensity change of nuri westward across the kuroshio in the luzon strait the 26 c isotherm shallows rapidly by half this and stronger mixing by wind ocean resonance preferentially cooled sea surface temperature and weakened the typhoon in scs a positive feedback mechanism is then described to explain the intensification of nuri over the western north pacific

driving mechanism of band structure of mean current over the continental shelf abstract a two layer numerical model is used to investigate the continental shelf circulation forced by western boundary currents along shelf edges emphasis is placed on an effect by frontal eddies or frontal waves which are reproduced in the model with the shelf edge along which a western boundary current is imposed after long term integration the model reaches the equilibrium state in which alternating bands of long term mean currents are found over the continental shelf the generation of the band structure is consistent with the observational results obtained by acoustic doppler current profilers on the shelf of the east china sea the western boundary current is accompanied by frontal waves and so vertical momentum transfer occurs because of the diffusive stretching topographic rossby waves are excited on the shelf slope by the vertical momentum transfer thereafter energy of the waves proceeds to flow toward the lower frequency limit by resonant interactions the along shelf wavenumber also

numerical study on the pattern and origins of kuroshio branches in the bottom water of southern east china sea in summer pattern and origins of kuroshio branches in the bottom water of southern east china sea ecs were carefully examined by numerical simulations based on the regional ocean modeling system roms together with observations model results show that in the bottom water of ecs the intrusion pattern of kuroshio is mainly composed of an offshore kuroshio branch current okbc which bifurcated from the kuroshio northeast of taiwan flows nearly along the isobath of similar to 100 m and a nearshore kuroshio branch current nkbc which originated from the kuroshio northeast of taiwan upwells northwestward gradually from similar to 250 m to similar to 60 m then turns to northeast around 27 5 degrees n 122 e thereafter flows northeastward along the isobath of similar to 60 m and finally reaches at 30 5 degrees n where it turns to east furthermore we found that the nkbc mostly originated in the kuroshio subsurface water 120 250 m east of taiwan whereas the okbc mainly stemmed from the kuroshio water 60 120 m east of taiwan this pattern and origins of okbc and nkbc well addressed the observational phenomena that off the coast of zhejiang province china there were colder less saline and more phosphate rich bottom water near the isobath of similar to 60 m rather than near the isobath of similar to 100 m in august 2009 finally it is proposed that on southern ecs continental shelf kuroshio exhibits its intrusion branches by an anticyclonical stair structure bottom stair nkbc middle stair okbc and top stair kuroshio surface branch kbc

kinematic dynamic and thermodynamic analysis of a weakly sheared severe thunderstorm over northern alabama abstract a kinematic dynamic and thermodynamic analysis of a weakly sheared airmass thunderstorm observed over northern alabama is presented most notable is the fact that the dominant cell in this storm closely resembles the byers and braham model for warm based airmass storms several phenomena never documented for this storm type are discussed one of these is a strong and deep downdraft observed at midlevels with an associated weak echo trench its origin appears to be related to a wake entrainment process a midlevel inflow which causes a visible constriction in the storm cloud is also observed this inflow results in a division of the thermal buoyancy into two maxima in the vertical one associated with the precipitation core and the other with strong positive vertical motions in the growing cumulus turret in addition a downdraft separate from that seen at midlevels develops at low levels and causes a microburst outflow at the surface this downdraft appears to be initiated by precipitation

cloud to ground lightning associated with the evolution of a multicell storm 1 the relationship of cloud to ground cg lightning strikes to the stages of updraft downdraft evolution is investigated in a multicell thunderstorm that occurred on 11 july 1989 during the north dakota thunderstorm project with only single doppler radar data available for this storm reflectivity and single doppler velocity signatures are used to identify individual cells within the storm and to deduce the stage of evolution within each cell cell evolution appeared to follow the thunderstorm project model of the late 1940s updraft growth and vertical development during the growing cumulus stage updraft peaking in the upper portion of the cell and rainy downdraft descending from the middle portion during the mature stage and lighter precipitation settling out during the dissipating stage on 11 july cells tended to occur in clusters each cluster consisting of growing mature and dissipating cells close together in both time and space no cg strikes were detected when the convective region of the storm contained only one cluster of cells all strikes occurred when there were two or more clusters of cells with only two exceptions strikes occurred in the convective region of the storm typically closer to growing mature cells than to dissipating cells these observations support the hypothesis that descending precipitation creates electrical conditions conducive to flashes reaching ground however these observations also suggest that the greater complexity of electrical structure due to the juxtaposition of several cells is especially conducive to cg flashes and can cause cg flashes to occur earlier in a new cell s life cycle than would otherwise be the case

phytoplankton blooms beneath the sea ice in the chukchi sea in the arctic ocean phytoplankton blooms on continental shelves are often limited by light availability and are therefore thought to be restricted to waters free of sea ice during july 2011 in the chukchi sea a large phytoplankton bloom was observed beneath fully consolidated pack ice and extended from the ice edge to 4100 km into the pack the bloom was composed primarily of diatoms with biomass reaching 1291 mg chlorophyll a m 2 and rates of carbon fixation as high as 3 7 g c m 2 d 1 although the sea ice where the bloom was observed was near 100 concentration and 0 8 1 2 m thick 30 40 of its surface was covered by melt ponds that transmitted 4 fold more light than adjacent areas of bare ice providing sufficient light for phytoplankton to bloom phytoplankton growth rates associated with the under ice bloom averaged 0 9 d 1

structure and variability of the kuroshio current in tokara strait four years of mooring array measurements in tokara strait south of kyushu japan from 1992 to 1996 are used to analyze the structure and temporal variability of the kuroshio current the mean kuroshio current in tokara strait shows a nearly permanent subsurface double core structure possibly due to topographic blockage effects the dominant variations of the kuroshio in tokara strait are separated into long term variability typically 100 day period and short term variability 10 days to 1 month according to spectrum and wavelet analysis the long term variability has a large horizontal scale across the strait with a striking twofold banded structure in spatial correlations this is due to the north south kuroshio axis shift that advects the double core structure of the mean current the axis shift can be indexed with the northeastward current velocity at the northernmost station a composite analysis using this index shows well defined northward and southward axis shift structures of the kuroshio current from the composite of the topex poseidon sea level anomaly in terms of this index the kuroshio axis shift and the current structure change are associated with a dipole shape sea level anomaly east of tokara strait on the other hand the short term variability of high kinetic energy only has a small horizontal scale within the northern part of the current which is related to frontal variability there exists a deep southwestward undercurrent below 600 m in the northern part of tokara strait flowing along the isobaths the undercurrent becomes stronger during the northward shift of the kuroshio axis while it almost disappears during the southward shift

boundary layer development over a tropical island during the maritime continent thunderstorm experiment abstract data collected during the maritime continent thunderstorm experiment mctex 10 november 10 december 1995 have been used to analyze boundary layer development and circulations over two almost flat tropical islands the two adjacent islands have a combined length of about 170 km from east to west and 70 km from north to south intense thunderstorms formed over these islands every day of the field campaign the boundary layer depth temperature and circulation over the island have been measured over the full diurnal cycle using a multiple radar analysis combined with surface and radiosonde measurements on average the island boundary layer depth reaches 1 5 km by early to midafternoon coinciding with the development of the deep convection thus the island boundary layer is significantly deeper than the typical tropical oceanic boundary layer in the midafternoon thunderstorm outflows and their associated cold pool stabilize the lower boundary layer suppressing late convection this is follo

episodic surface intrusions in the yellow sea during relaxation of northerly winds the surface currents over the yellow and east china seas are mapped from the geostationary ocean color imager goci based on a composite of six intrusion events in january april the strong northward surface current in the yellow sea is shown to be concentrated along the deep trough accompanied by a broad northward surface current over the east china sea from the corresponding surface winds the episodic northward surface flow bursts appear to be associated with abrupt changes from the strong northerly winds to weak southerly winds during cold front passages a three dimensional model driven with observed surface winds is used to simulate the observed shelf wide response to northerly winds there is an outstanding agreement between the simulated and observed surface currents the surface intrusion in the yellow sea is shown to be driven primarily by a barotropic longitudinal surface slope while the strong northward current in the east china sea is associated with a coastal trapped wave moreover the surface intrusion is associated with a large volume transport suggesting that the transient intrusions could be important in the northward heat transport the unprecedented capability of goci satellite in providing a regional circulation pattern in conjunction with complementary model simulations could contribute greatly to understanding of the dynamics of the yellow and east china seas

on the origin of the tsushima warm current the origin of the tsushima warm current referred to as twc was investigated by surface drifter experiments and conductivity temperature and depth ctd surveys in the northeastern east china sea ecs at three different times july 1991 and april and november 1992 trajectories of 10 satellite tracked drifters provide direct information for the first time on the surface flow patterns in each season and ctd observations allow identification of warm and saline twc waters the results of the experiments argue against two historical concepts of twc origins i e 1 a northward flow transporting warm and saline water through the deep trough southwest of kyushu toward the korea strait after separation from the kuroshio and 2 a northeastward continuation of the taiwan current tc on the shelf of ecs after passing through the taiwan strait a persistent northward current was found to exist both on the shelf west of the trough and on the western flank of the trough the northward flow seems to bifurcate around the northwestern corner of the trough splitting into a northward continuing flow on the shelf of 100 150 m and an eastward flow along the northern wall of the trough the northward flow on the shelf which might be the shore fringe of the kuroshio corresponds to the origin of twc entering the korea strait the eastward flow on the northern slope turned back to the south along the west coast of kyushu and eventually joined the kuroshio this structure was accompanied by an anticyclonic eddy in the northern trough the second concept that of twc originating from tc contradicts the observed differences in physical properties between twc and tc waters the saline water in the taiwan strait flows out intermittently only during late winter early spring and its salinity during other seasons is lower than that of the twc water in the korea strait experiments also indicated a seasonal shift of drifter paths in the northeastern ecs and coexistence of cyclonic and anticyclonic eddies in the trough during the cold season

mass flux characteristics of tropical cumulus clouds from wind profiler observations at darwin australia abstractcumulus parameterizations in weather and climate models frequently apply mass flux schemes in their description of tropical convection mass flux constitutes the product of the fractional area covered by convection in a model grid box and the vertical velocity in cumulus clouds however vertical velocities are difficult to observe on gcm scales making the evaluation of mass flux schemes difficult here the authors combine high temporal resolution observations of in cloud vertical velocities derived from a pair of wind profilers over two wet seasons at darwin with physical properties of precipitating clouds cloud top heights cth convective stratiform classification derived from the darwin c band polarimetric radar to provide estimates of cumulus mass flux and its constituents the length of this dataset allows for investigations of the contributions from different cumulus cloud types namely congestus deep and overshooting convection to the overall mass flux and of the influence of large

a younger thinner arctic ice cover increased potential for rapid extensive sea ice loss 1 satellite derived estimates of sea ice age and thickness are combined to produce a proxy ice thickness record for 1982 to the present these data show that in addition to the well documented loss of perennial ice cover as a whole the amount of oldest and thickest ice within the remaining multiyear ice pack has declined significantly the oldest ice types have essentially disappeared and 58 of the multiyear ice now consists of relatively young 2 and 3 year old ice compared to 35 in the mid 1980s ice coverage in summer 2007 reached a record minimum with ice extent declining by 42 compared to conditions in the 1980s the much reduced extent of the oldest and thickest ice in combination with other factors such as ice transport that assist the ice albedo feedback by exposing more open water help explain this large and abrupt ice loss

on kuroshio front fluctuations in the east china sea using satellite and in situ observational data fluctuations of the kuroshio front in the east china sea and their relation to variations of the kuroshio stream around the tokara strait are investigated using consecutive satellite images sea level data as well as water temperature records from a japan meteorological agency buoy station and a ferryboat which crosses the tokara strait meanders of the kuroshio front with typical horizontal scales of 100 to 150 km and wave periods of 14 to 20 days are found to appear ubiquitously in the east china sea the front meanders originate upstream over the continental slope and evolve rapidly while propagating downstream at speeds of 20 to 26 cm s 1 downstream southwest of kyushu the fully developed meanders sometimes take the form of warm filaments and when the volume transport of the kuroshio is large they may develop into shed off warm eddies previous observations based on ferryboat temperature records have revealed the repeated northward migration of a clear sea surface temperature sst front across the tokara strait it is shown that this northward migration of the sst front corresponds to the passage of the kuroshio front meanders across the tokara strait and that the unclear southward migration of the sst front is due to the presence of mixed water behind each meander the kuroshio front meanders in the east china sea are further found to be closely related to the north southward movement of the entire kuroshio stream in the tokara strait a lag of about 10 days exists between the time the front meanders reach the tokara strait and the kuroshio stream there shifts to its northernmost position

water exchange across isobaths over the continental shelf of the east china sea abstractonshore and offshore currents and the associated volume transport across three isobaths 50 100 and 200 m over the continental shelf of the east china sea were examined using daily reanalysis data in 1993 2012 after being averaged along the isobaths the velocities across 100 and 50 m are onshore in the bottom layer but offshore in the surface layer in contrast those across the 200 m isobath are onshore in the surface and bottom layers but without a clear direction in the midlayer suggesting a three layer structure the surface offshore current across the 100 m isobath mainly arises from the taiwan strait current while the surface onshore current across the 200 m isobath mainly arises from the kuroshio both of which converge in the area between the 100 and 200 m isobaths and flow toward the tsushima strait the control of bottom ekman dynamics on the onshore bottom currents is important at the 100 m isobath partly important at the 200 m isobath and slightly important at the 50 m isobat

instability of the north pacific subtropical countercurrent abstractthe north pacific subtropical countercurrent stcc has a weak eastward velocity near the surface but the region is populated with eddies studies have shown that the stcc is baroclinically unstable with a peak growth rate of 0 015 day 1 in march and the 60 day growth time has been used to explain the peak eddy kinetic energy eke in may observed from satellites it is argued here that this growth time from previously published normal mode instability analyses is too slow growth rates calculated from an initial value problem without the normal mode assumption are found to be 1 5 to 2 times faster and at shorter wavelengths due to the existence of i nonmodal solutions and ii sea surface temperature front in the mixed layer in winter at interannual time scales it is shown that because of rapid surface adjustments the stcc geostrophic shear hence also the instability growth is approximately in phase with surface forcing leading to eke modulation that peaks approximately 10 months later

intrusion of the kuroshio subsurface water in the southern east china sea and its variation in 2014 and 2015 traced by dissolved inorganic iodine species abstract the circulation systems and ecological environment of the east china sea ecs are greatly influenced by the kuroshio the nutrient rich kuroshio subsurface water kssw has been subject to considerable research attention but the intrusion pathway extent and variation of the kssw over the entire southern ecs shelf are still debated in june 2015 the dissolved inorganic iodine species diis were determined and hydrographic data were collected and analyzed in the southern ecs analysis of the collected data suggests that the kssw mainly intrudes onto the ecs shelf from northeast of taiwan and bifurcates into a nearshore branch and an offshore branch the nearshore branch ultimately appears in the subsurface layer within the 50 m isobath off the zhejiang coast north of 30 n and the offshore branch flows along the 100 m isobath and covers the area outside the 80 m isobath another kssw intrusion along the shelf edge is located at 28 n this additional kssw intrusion is weaker and the offshore area in the southern ecs is mainly influenced by the kssw intrusion northeast of taiwan compared with the kssw intrusion on the ecs continental shelf depth

a mass flux scheme view of a high resolution simulation of a transition from shallow to deep cumulus convection in this paper an idealized high resolution simulation of a gradually forced transition from shallow nonprecipitating to deep precipitating cumulus convection is described how the cloud and transport statistics evolve as the convection deepens is explored and the collected statistics are used to evaluate assumptions in current cumulus schemes the statistical analysis methodologies that are used do not require tracing the history of individual clouds or air parcels instead they rely on probing the ensemble characteristics of cumulus convection in the large model dataset they appear to be an attractive way for analyzing outputs from cloud resolving numerical experiments throughout the simulation it is found that 1 the initial thermodynamic properties of the updrafts at the cloud base have rather tight distributions 2 contrary to the assumption made in many cumulus schemes nearly undiluted air parcels are too infrequent to be relevant to any stage of the simulated convection and 3 a simple model with a spectrum of entraining plumes appears to reproduce most features of the cloudy updrafts but significantly overpredicts the mass flux as the updrafts approach their levels of zero buoyancy a buoyancy sorting model was suggested as a potential remedy the organized circulations of cold pools seem to create clouds with larger sized bases and may correspondingly contribute to their smaller lateral entrainment rates our results do not support a mass flux closure based solely on convective available potential energy cape and are in general agreement with a convective inhibition cin based closure the general similarity in the ensemble characteristics of shallow and deep convection and the continuous evolution of the thermodynamic structure during the transition provide justification for developing a single unified cumulus parameterization that encompasses both shallow and deep convection

of basins plains and trenches systematics and distribution of solenogastres mollusca aplacophora in the northwest pacific abstract solenogastres mollusca aplacophora form a common part of the benthic malacofauna in the deep sea but their diversity in the northwest pacific is poorly understood in this study we analyze the systematics and distribution of solenogastres sampled during the kuril kamchatka biodiversity studies ii expedition to the hadal kuril kamchatka trench in the framework of previous expeditions to the shallow bathyal areas of the japanese coast the abyssal kuril basin in the sea of okhotsk and the open abyssal plain of the northwest pacific this unique dataset from adjacent regions extending from bathyal to hadal zones enables us to study bathymetric and geographic distribution ranges in this neglected deep sea clade for the first time our applied species delineation in these taxonomically challenging aplacophoran molluscs relies on an integrative approach combining scleritome characters with molecular analyses a first molecular phylogenetic study based on two mitochondrial markers reveals conflict with traditional systematics and suggests the need to revise at least two polyphyletic families and the polyphyletic order cavibelonia in total 192 specimens could be grouped within 60 candidate species which present a surprisingly rich abyssal fauna and includes the first representatives of solenogastres at hadal depths we found a high proportion of singletons and little faunal overlap between the investigated regions and depths suggesting that the diversity of the abyssal and hadal solenogastres is not entirely determined by source sink dynamics from the bathyal slope rather there is evidence for abyssal source populations supporting the presence of endemic abyssal and potentially even hadal species our molecular data reject the kuril kamchatka trench as an insurmountable barrier of dispersal for solenogastres with one species present at both sides of the trench remarkably one species from the kuril kamchatka trench shows a vertical distribution extending over more than 6 000 m overall our study more than doubles the global number of solenogaster species from abyssal depths provides first records of a unique hadal solenogaster fauna and delivers valuable insights into distribution ranges of these deep sea molluscs

characterizing surface circulation in the taiwan strait during ne monsoon from geostationary ocean color imager abstract the taiwan strait is the only channel connecting the south china sea scs and the east china sea ecs and plays a key role in the material exchanges between scs and ecs the region however is poorly sampled during the northeast ne monsoon when severe weather hinders shipboard measurements in this study the surface circulations in the taiwan strait and the adjacent east china sea are derived from the geostationary ocean color imager goci with a high spatiotemporal resolution the satellite observations are limited by cloud over nevertheless they provide the only surface flow observations useful in hypothesis testing it is demonstrated that the transient surface currents can be classified into three regimes a southwestward flow for strong winds a northeastward flow for weak winds and a cross strait flow for moderate winds the satellite observations are also valuable in validating model currents two high resolution global ocean reanalysis products the hybrid coordinate ocean model hycom and the copernicus marine environment monitoring service cmems are examined the reanalysis products are generally consistent with the satellite observations the cmems moreover shows a superior performance this study illustrates the unique capability of the geostationary ocean color satellite in providing spatially extensive surface flow observations in broad shelf regions where current meter data are sparse or non existent

impact of mesoscale eddies on kuroshio intrusion variability northeast of taiwan abundant mesoscale eddies propagate to the east of taiwan and affect the kuroshio current and its onshore intrusion northeast of taiwan but the dynamical process of how eddy activities modulate the kuroshio intrusion is still unclear in this study in situ ocean velocity observations drifter trajectories tide gauge measurements satellite sea surface height data and assimilative hybrid coordinate ocean model hycom reanalysis outputs were used to analyze a cyclonic eddy induced large kuroshio onshore intrusion during late autumn 2008 along with nine anticyclonic eddy events and seven cyclonic eddy events extracted from long term hycom reanalysis outputs the variability of the eddy induced intrusion were quantified the impacts of the cyclonic eddy and the anticyclonic eddy were opposite under the impact of cyclonic anticyclonic eddy the total onshore intrusion between 122 e and 124 e across the 200 m isobaths was decreased increased by 15 7 7 3 while the onshore intrusion west of 122 6 e and the northeastward current on the outer shelf was increased decreased by 30 6 4 7 and 31 10 1 respectively the arrival of cyclonic anticyclonic eddy brought positive negative potential vorticity pv flux and modulated the local ocean vertical stratification which weakened enhanced the cross slope pv gradient and the shelf slope constraint on the upper layer current therefore favored inhibited the kuroshio onshore intrusion this article is protected by copyright all rights reserved

new cnes cls09 global mean dynamic topography computed from the combination of grace data altimetry and in situ measurements 1 an accurate knowledge of the ocean mean dynamic topography mdt is mandatory for the optimal use of altimetric data including their assimilation into operational ocean forecasting systems a new global 1 4 resolution mdt was computed for the 1993 1999 time period with improved data and methodology compared to the previous rio05 mdt field first a large scale mdt is obtained from the cls01 altimetric mean sea surface and a recent geoid model computed from 4 5 years of grace gravity recovery and climate experiment data altimetric sea level anomalies and in situ measurements are then combined to compute synthetic estimates of the mdt and the corresponding mean currents while the rio05 mdt was based on 10 years of in situ dynamic heights and drifting buoy velocities the new field benefits from an enlarged data set of in situ measurements ranging from 1993 to 2008 and includes all hydrological profiles from the argo array moreover the processing of the in situ data has been updated a new ekman model was developed to extract the geostrophic velocity component from the drifting buoy measurements the handling of hydrologic measurements has also been revisited compared to the previous rio05 solution the new global mdt resolves much stronger gradients in western boundary currents with mean velocities being doubled in some places moreover in comparison to several other recent mdt estimates we find that the new cnes cls09 mdt is in better agreement with independent in situ observations

bloom dynamics in early opening waters of the arctic ocean we measured the isotopic composition and accumulation of particulate organic matter pom and the uptake of carbon c and nitrogen n in an early bloom of the most productive recurring polynya of the arctic ocean the estimated compensation irradiance at the onset of the bloom was similar to the average for the north atlantic ocean implying that shallow mixing was of critical importance for the bloom s early initiation planktonic pom had a much lower d 13 c than ice pom suggesting that ice algae contributed little to the pelagic biomass the overall isotopic fractionation of pelagic n during bloom development was consistent with in situ diatom growth under saturating irradiance and limiting no soon after the ice cleared rapid physiological changes induced an order of 2 3 magnitude increase in the c and no uptake capacity of diatoms leading to very high f ratios no uptake total 2 2 3 3 n uptake most of the no taken up appeared in the pom so that little net release of reduced n occurred during 2 3 the period of active growth given the tight coupling between photosynthesis and no uptake under n limitation 2 3 the magnitude of primary production in the arctic ocean is expected to respond to changes in n supply

north atlantic oscillation effect on interannual variability in winter precipitation over the gulf stream abstractin winter the warm water of the gulf stream anchors a salient precipitation band previous studies suggested a close relationship between the sea surface temperature sst front and the pr

the three dimensional morphology of simulated and observed convective storms over southern england abstracta set of high resolution radar observations of convective storms has been collected to evaluate such storms in the met office unified model during the dynamical and microphysical evolution of convective storms dymecs project the 3 ghz chilbolton advanced meteorological radar was set up with a scan scheduling algorithm to automatically track convective storms identified in real time from the operational rainfall radar network more than 1000 storm observations gathered over 15 days in 2011 and 2012 are used to evaluate the model under various synoptic conditions supporting convection in terms of the detailed three dimensional morphology storms in the 1500 m grid length simulations are shown to produce horizontal structures a factor of 1 5 2 wider compared to radar observations a set of nested model runs at grid lengths down to 100 m show that the models converge in terms of storm width but the storm structures in the simulations with the smallest grid lengths are too narrow and too intense c

cross flows in the taiwan strait in winter abstractin winter a branch of the china coastal current can turn in the taiwan strait to join the poleward flowing taiwan coastal current the associated cross strait flows have been inferred from hydrographic and satellite data from observed abundances off northwestern taiwan of cold water copepod species calanus sinicus and in late march of 2012 also from debris found along the northwestern shore of taiwan of a ship that broke two weeks earlier off the coast of china the dynamics related to such cross flows have not been previously explained and are the focus of this study using analytical and numerical models it is shown that the strait s currents can be classified into three regimes depending on the strength of the winter monsoon equatorward poleward for northeasterly winds stronger weaker than an upper lower bound and cross strait flows for relaxing northeasterly winds between the two bounds these regimes are related to the formation of the stationary rossby wave over the changyun ridge

changes in arctic sea ice result in increasing light transmittance and absorption 1 arctic sea ice has declined and become thinner and younger more seasonal during the last decade one consequence of this is that the surface energy budget of the arctic ocean is changing while the role of surface albedo has been studied intensively it is still widely unknown how much light penetrates through sea ice into the upper ocean affecting sea ice mass balance ecosystems and geochemical processes here we present the first large scale under ice light measurements operating spectral radiometers on a remotely operated vehicle rov under arctic sea ice in summer this data set is used to produce an arctic wide map of light distribution under summer sea ice our results show that transmittance through first year ice fyi 0 11 was almost three times larger than through multi year ice myi 0 04 and that this is mostly caused by the larger melt pond coverage of fyi 42 vs 23 also energy absorption was 50 larger in fyi than in myi thus a continuation of the observed sea ice changes will increase the amount of light penetrating into the arctic ocean enhancing sea ice melt and affecting sea ice and upper ocean ecosystems

kuroshio subsurface water feeds the wintertime taiwan warm current on the inner east china sea shelf the taiwan warm current twc has an overwhelming influence on the heat salt and nutrients balance on one of the broadest shelf in the world the east china sea shelf in winter the twc flows in an unusual upwind direction and reaches the changjiang yangtze river estuary but its origin and pathway are intensely debated here combined evidences from current measurement hydrographic and stable isotopic data all suggest that the wintertime twc intrusion off the changjiang estuary mainly originates from the kuroshio subsurface water northeast of taiwan rather than from the taiwan strait warm water the kuroshio branched water northeast of taiwan can intrude into the inner shelf near the zhe min coast via bottom layer manifesting by a pronounced boundary at 50 m isobath around 28 n and thereby feeds the twc intrusion into the changjiang estuary the intrusion complicates the hydrological process in the estuary and shelf sea and its impact on marine environment deserves more research attentions

kuroshio meanders in the east china sea abstract an array of seven inverted echo sounders was moored along and across the kuroshio in the east china sea for more than one year the data from this array show evidence of energetic meanders with periods of 7 11 and 16 days the respective phase velocities of these meanders are 28 20 and 17 km day 1 downstream the 7 and 16 day waves are intermittent but the 11 day waves are present throughout the deployment the instability responsible for these waves is investigated with a spectral numerical model applied to a background state representing the kuroshio in this region the fastest growing instability from the model has e folding growth time of 2 days period of 12 days and phase velocity of 18 km day 1 downstream it appears to be a close representation of the 11 day wave seen in the observational data such a model has been previously used to represent meanders in the gulf stream at similar latitudes off the east coast of the united states the kuroshio meanders have approximately half the