the evolution of oceanic and atmospheric anomalies in the northeast pacific during the el nino and la nina events of 1995 2001 abstract from late 1995 through early 2001 three major interannual climate events occurred in the tropical pacific the 1995 97 la nina ln 1997 98 el nino en and 1998 2001 ln we analyze atmospheric and upper oceanic anomalies in the northeast pacific nep during these events and compare them to anomalies both elsewhere in the north and tropical pacific and to typical en and ln anomaly patterns the atmospheric and oceanic anomalies varied strongly on intraseasonal and interannual scales during the 1995 97 ln and 1997 98 en the northeast pacific was dominated by negative slp and cyclonic wind anomalies and by upper ocean temperature and sea surface height ssh anomalies the latter were positive along the north american west coast and in the nep thermal anomaly pool between hawaii vancouver island and baja california and negative in the central north pacific this atmospheric oceanic anomaly pattern is typical of en an eastward shift in the atmospheric teleconnection from east asia created en like anomalies in the nep during the 1995 97 ln well before the 1997 98 en had begun the persistence of negative sea level pressure slp and cyclonic wind anomalies in the nep during the 1997 98 en intensified pre existing upper oceanic anomalies atmospheric anomalies were shifted eastward during late 1996 early 1998 leading to a similar onshore shift of oceanic anomalies this produced exceptionally strong positive upper ocean temperature and ssh anomalies along the west coast during the 1997 98 en and explains the unusual coastal occurrences of several species of large pelagic warm water fishes the growth and eastward shift of these pre existing anomalies does not appear to have been linked to tropical pacific en anomalies until late 1997 when a clear atmospheric teleconnection between the two regions developed prior to this remote atmospheric impacts on the nep were primarily from east asia as the 1998 2001 ln developed nep anomalies began reversing toward the typical ln pattern this led to predominantly negative slp and cyclonic wind anomalies in the nep and upper ocean temperature and ssh anomalies that were mainly negative along the west coast and positive in the central north pacific the persistence of these anomalies into mid 2001 and a number of concurrent biological changes in the nep suggest that a decadal climate shift may have occurred in late 1998 during 1995 2001 nep oceanic anomalies tracked the overlying atmospheric anomalies as indicated by the maintenance of a characteristic spatial relationship between these anomalies in particular wind stress curl and ssh anomalies in the nep maintained an inverse relationship that strengthened and shifted eastward toward the west coast during late 1996 early 1998 this consistent relationship indicates that anomalous ekman transport driven by regional atmospheric forcing was an important contributor to temperature and ssh anomalies in the nep and ccs during the 1997 98 en other studies have shown that coastal propagations originating from the tropical pacific also may have contributed to coastal nep anomalies during this en our results indicate that at least some of this coastal anomaly signal may have been generated by regional atmospheric forcing within the nep

the 1997 1998 oceanic el nino signal along the southeast and northeast pacific boundaries an altimetric view changes in the sea surface heights ssh and geostrophic currents along the eastern boundaries of the pacific north central and south america are examined during the 1997 1998 el nino using altimeter data and proxy winds these show that symmetric ssh signals left the equator and propagated into both hemispheres in two episodes with primary periods of high equatorial ssh during may july and october december 1997 these are the distant signals from the mid latitude perspective as the signals spread poleward in each hemisphere their loss of symmetry demonstrates the degree to which they were altered by topographic features local winds and or local currents the first four eofs are calculated for 2 d ssh fields in 10 wide strips along the eastern margins 60 n 60 s and extending out along the equator from the coast to 110 w these account for approximately 40 of the overall variability and represent the main features of the seasonal cycles and el nino interannual variability snapshots of the 2 d ssh fields depict the structure of the el nino signal at different phases of its evolution

fine scale variability of isopycnal salinity in the california current system this paper examines the finescale structure and seasonal fluctuations of the isopycnal salinity of the california current system from 2007 to 2013 using temperature and salinity profiles obtained from a series of underwater glider surveys the seasonal mean distributions of the spectral power of the isopycnal salinity gradient averaged over submesoscale 12 30 km and mesoscale 30 60 km ranges along three survey lines off monterey bay point conception and dana point were obtained from 298 transects the mesoscale and submesoscale variance increased as coastal upwelling caused the isopycnal salinity gradient to steepen areas of elevated variance were clearly observed around the salinity front during the summer then spread offshore through the fall and winter the high finescale variances were observed typically above 25 8 kg m 3 and decreased with depth to a minimum at around 26 3 kg m 3 the mean spectral slope of the isopycnal salinity gradient with respect to wavenumber was 0 19 0 27 over the horizontal scale of 12 60 km and 31 to 35 of the spectra had significantly positive slopes in contrast the spectral slope over 12 30 km was mostly flat with mean values of 0 025 0 32 an increase in submesoscale variability accompanying the steepening of the spectral slope was often observed in inshore areas e g off monterey bay in winter where a sharp front developed between the california current and the california under current and the lower layers of the southern california bight where vigorous interaction between a synoptic current and bottom topography is to be expected

on sampling the ocean using underwater gliders surface to 1000 m and back took 5 6 h and covered 5 3 km resulting in a horizontal speed of 0 26 m s 1 seasoar undulated between the surface and 400 m completing a cycle in 11 min while covering 2 6 km for a speed of 3 9 m s 1 adjacent profiles of temperature and salinity are compared between the two platforms to prove that each is accurate spray and seasoar data are compared through sections isopycnal spatial series and wave number spectra the relative slowness of the glider results in the projection of high frequency oceanic variability such as internal waves onto spatial structure the projection is caused by doppler smearing because of finite speed and aliasing due to discrete sampling the projected variability is apparent in properties measured on depth surfaces or in isopycnal depth no projected variability is seen in observations of properties on constant density surfaces because internal waves are intrinsically filtered wave number spectra suggest that projected variability affects properties at constant depth at wavelengths shorter than 30 km these results imply that isobaric quantities like geostrophic shear are valid at wavelengths longer than 30 km while isopycnal quantities like spice may be analyzed for scales as small as a glider measures

seasonal and interannual variability in along slope oceanic properties off the us west coast inferences from a high resolution regional model a 6 year 2009 2014 simulation using a 2 km horizontal resolution ocean circulation model of the northeast pacific coast is analyzed with focus on seasonal and interannual variability in along slope subsurface oceanic properties specifically the fields are sampled on the isopycnal surface 26 5 kg m 3 that is found between depths of 150 and 300 m below the ocean surface over the continental slope the fields analyzed include the depth z26 5 temperature t26 5 along slope currents 26 5 and the average potential vorticity pv between 26 5 and 26 25 kg m 3 each field is averaged in the cross shore direction over the continental slope and presented as a function of the alongshore coordinate and time the seasonal cycle in z26 5 shows a coherent upwelling downwelling pattern from mexico to canada propagating to the north with a speed of 0 5 m s 1 the anomalously deep 20 m z26 5 displacement in spring summer 2014 is forced by the southern boundary condition at 24 n as a manifestation of an emerging strong el nino the seasonal cycle in t26 5 is most pronounced between 36 53 n indicating that subarctic waters are replaced by warmer californian waters in summer with the speed close 0 15 m s 1 which is consistent with earlier estimates of the undercurrent speed and also present 26 5 analyses the seasonal patterns and anomalies in z26 5 and t26 5 find confirmation in available long term glider and ship borne observations the pv seasonality over the slope is qualitatively different to the south and north of the southern edge of heceta bank 43 9 n

poleward flows in the southern california current system glider observations and numerical simulation 1 three years of continuous spray glider observations in the southern california current system ccs are combined with a numerical simulation to describe the mean and variability of poleward flows in the southern ccs gliders provide upper ocean observations with good across shore and temporal resolution along two across shore survey lines while the numerical simulation provides a dynamically consistent estimate of the ocean state persistent poleward flows are observed in three areas within 100 km of the coast at point conception within the southern california bight scb and offshore of the scb and the santa rosa ridge srr poleward transport by the flows within the scb and offshore of the srr exceeds the poleward transport off point conception suggesting that the poleward flows are not continuous over the 225 km between observation lines the numerical simulation shows offshore transport between the survey lines that is consistent with some of the poleward flow turning offshore before reaching point conception the poleward current offshore of the srr is unique in that it is strongest at depths greater than 350 m and it is observed to migrate westward away from the coast this westward propagation is tied to westward propagating density anomalies originating in the scb during the spring summer upwelling season when wind stress curl is most strongly positive the across shore wave number frequency and phase speed of the westward propagation and the lack of across shore transport of salinity along isopycnals are consistent with first mode baroclinic rossby dynamics

satellite measurements reveal persistent small scale features in ocean winds four year averages of 25 kilometer resolution measurements of near surface wind speed and direction over the global ocean from the quikscat satellite radar scatterometer reveal the existence of surprisingly persistent small scale features in the dynamically and thermodynamically important curl and divergence of the wind stress air sea interaction over sea surface temperature fronts throughout the world ocean is evident in both the curl and divergence fields as are the influences of islands and coastal mountains ocean currents such as the gulf stream generate distinctive patterns in the curl field these previously unresolved features have important implications for oceanographic and air sea interaction research

the evolution and depth structure of shelf and slope temperatures and velocities during the 1997 1998 el nino near point conception california abstract moored survey and drifter observations are used to describe the evolution of temperature sea level velocity and salinity from 1997 to 1998 over the california shelf between san luis obispo bay and the eastern entrance to the santa barbara channel the dominant event during this time was the 1997 1998 el nino its relation to background seasonal and interannual variability depended on which property is considered subsurface temperature and local sea level showed extreme anomalies between march 1997 and october 1998 three distinct peaks occurred the first two are associated with the regional response to el nino while the cause of the third remains unclear the first peaked in june 1997 and decayed until august the main el nino peak reached maximum amplitude between november 1997 and january 1998 after the collapse of the regional el nino anomaly in february 1998 a final peak occurred locally during the summer of 1998 the central result presented here concerns the spatial structure of temperature during these events the initial peak was surface intensified and was barely detectable at 45 m its amplitude varied with position along the coast decaying with distance north the main peak showed a strong signal down to at least 200 m the amplitude and timing of temperature anomalies during this event were depth dependent the largest absolute amplitudes relative to seasonal cycles were in excess of 4 c and occurred between 45 and 65 m depth the anomalies reached their maximum values at later time with increasing depth between october 1997 and january 1998 the amplitude of this main peak was comparable at all mooring sites the final peak in august 1998 had a comparable amplitude at all mooring sites to a depth of 100 m temperature increases during the three events were accompanied by a corresponding rise in sea level the el nino signals in currents and salinity are more difficult to distinguish from background variability than those in temperatures and sea level however stronger than average poleward flow was observed at the eastern entrance to the santa barbara channel between 5 and 100 m depth for most of 1997 and there are indications for greater than usual poleward flow over the santa maria basin in fall 1997 surface drifter evidence although qualitative also suggests greater than usual poleward displacement in november 1997 relative to other years along with increased temperature survey observations of salinity suggest changes to the regional temperature salinity relation during november 1997 with greater than usual salinity at temperatures below 12 c

anomalous winter winds decrease 2014 transition zone productivity in the ne pacific wind driven transport from the north pacific in winter provides nutrients to a highly productive region in the transition zone between the subarctic and subtropics this region supports many species of fish marine mammals and seabirds in winter 2013 2014 anomalous winds from the south weakened nutrient transport in the eastern north pacific resulting in substantial decreases in phytoplankton biomass by january 2014 waters were warmer than usual by 3 5 c at the center of an affected area covering 1 5 106 km2 south of this area winter chlorophyll levels dropped to the lowest levels seen since the sea viewing wide field of view sensor satellite began taking measurements in 1997 it is anticipated that impacts will be felt in some fisheries and among migrating predators this coming year

archean inheritance in zircon from late paleozoic granites from the avalon zone of southeastern new england an african connection abstract in southeastern new england the narragansett pier granite locally intrudes carboniferous metasedimentary rocks of the narragansett basin and yields a monazite u pb permian emplacement age of 273 2ma zircon from the narragansett pier granite contains a minor but detectable amount of an older inherited component and shows modern loss of lead zircon from the late stage aplitic westerly granite exhibits a more pronounced lead inheritance permitting the inherited component to be identified as late archean such old relict zircon has not been previously recognized in proterozoic to paleozoic igneous rocks in new england and may be restricted to late paleozoic rocks of the avalon zone we suggest that the archean crustal component reflects an african connection in which old archean crust was underplated to the avalon zone microplate in the late paleozoic during collision of gondwanaland with avalonia

biogeochemical anomalies at two southern california current system moorings during the 2014 2016 warm anomaly el nino sequence author s lilly le send u lankhorst m martz tr feely ra sutton aj ohman md abstract 2019 american geophysical union all rights reserved we analyzed impacts of the 2014 2015 pacific warm anomaly and 2015 2016 el nino on physical and biogeochemical variables at two southern california current system moorings cce2 nearshore upwelling off point conception cce1 offshore california current nitrate and chl a fluorescence were l1 m and l1 standardized fluorescence unit respectively at cce2 for the entire durations of the warm anomaly and el nino the two longest periods of such low values in our time series negative nitrate and chl a anomalies at cce2 were interrupted briefly by upwelling conditions in spring 2015 near surface temperature anomalies appeared simultaneously at both moorings in spring 2014 indicating region wide onset of warm anomaly temperatures although sustained negative nitrate and chl a anomalies only occurred offshore at cce1 during el nino summer 2015 to spring 2016 warm anomaly temperature changes were expressed more strongly in near surface l40 m than subsurface 75 m waters at both moorings while el nino produced comparable temperature anomalies at near surface and subsurface depths nearshore aragonite at 76 m showed notably fewer undersaturation events during both warm periods suggesting an environment more conducive to calcifying organisms planktonic calcifying molluscs pteropods and heteropods increased markedly in springs 2014 and 2016 and remained modestly elevated in spring 2015 moorings provide high frequency measurements essential for resolving the onset timing of anomalous conditions and frequency and duration of short term days to weeks perturbations reduced nitrate and aragonite undersaturation events that can affect marine organisms

the 2014 2015 warming anomaly in the southern california current system observed by underwater gliders large scale patterns of positive temperature anomalies persisted throughout the surface waters of the north pacific ocean during 2014 2015 in the southern california current system measurements by our sustained network of underwater gliders reveal the coastal effects of the recent warming regional upper ocean temperature anomalies were greatest since the initiation of the glider network in 2006 additional observed physical anomalies included a depressed thermocline high stratification and freshening induced biological consequences included changes in the vertical distribution of chlorophyll fluorescence contemporaneous surface heat flux and wind strength perturbations suggest that local anomalous atmospheric forcing caused the unusual oceanic conditions

kinematic constraints on buckling a lithospheric scale orocline along the northern margin of gondwana a geologic synthesis abstract the paleozoic variscan orogeny was a large scale collisional event involving amalgamation of multiple continents and micro continents existing data suggests oroclinal buckling of an originally near linear convergent margin during the last stages of variscan deformation in the late paleozoic closure of the rheic ocean resulted in e w shortening present day coordinates in the carboniferous producing a near linear n s trending east verging belt subsequent n s shortening near the carb permian boundary resulted in oroclinal buckling this late stage orogenic event remains an enigmatic part of final pangea amalgamation the present day arc curvature of the variscan has inspired many tectonic models with little agreement between them while there is general consensus that two separate phases of deformation occurred various models consider that curvature was caused by dextral transpression around a gondwana indentor strike slip wrench tectonics or a change in tectonic transport direction due to changing stress fields more recent models explain the curvature as an orocline with potentially two opposite facing bends caused by secondary rotations deciphering the kinematic history of curved orogens is difficult and requires establishment of two deformation phases an initial compressive phase that forms a relatively linear belt and a second phase that causes vertical axis rotation of the orogenic limbs historically the most robust technique to accurately quantify vertical axis rotation in curved orogens is paleomagnetic analysis but recently other types of data including fracture geochemical petrologic paleo current and calcite twin data have been used to corroborate secondary buckling a review of existing and new variscan data from iberia is presented that argues for secondary buckling of an originally linear orogenic system together these data constrain oroclinal buckling of the cantabrian orocline to have occurred in about 10 ma during the latest carboniferous which agrees well with recent geodynamical models and structural data that relate oroclinal buckling with lithospheric delamination in the variscan

coastal upwelling in the california current system abstract coastal upwelling in the california current system has been the subject of large scale studies off california and baja california and of small scale studies off oregon recent studies of the winds along the entire coast from 25 n to 50 n indicate that there are significant along shore variations in the strength of coastal upwelling which are reflected in the observed temperature distribution active upwelling appears to be restricted to a narrow coastal band about 10 25 km wide along the entire coast but the region influenced by coastal upwelling may be much wider intensive observations of the upwelling zone during summer off oregon show the presence of a southward coastal jet at the surface a mean vertical shear a poleward undercurrent along the bottom and persistently sloping isopycnals over the continental shelf most of the upwelling there occurs during relatively short periods several days long of upwelling favorable winds during the upwelling season off oregon the offshore ekman transport is carried by the surface ekman layer and the onshore return flow occurs through a quasi geostrophic interior it is not known whether the structure and dynamics observed off oregon are typical of the upwelling zone along the entire coast though some of the same features have been observed off baja california current and future research will eventually show whether the oregon results are also applicable in the region of persistently strong upwelling favorable winds off northern california and in the region of complex bathymetry off central and southern california

the flow of the undercurrent over the continental borderland off southern california 1 iniroduction 2 background the bottom topography off southern california has been the cc a slow had equatornard flow is the eastern limb of termed a continental borderland to distinguish it from the ordinary the large scale anticyclonic gyre of the temperate north pacific shelf slope morphology found along most continental margins ocean the cc carries relatively cool low salinity waters of shepard and emuy 19411 islands shallow banks basins and subarctic origin to lower latitudes on average the core of the cc troughs form a complex bathymetric region extending from the has velocities of 0 10 to 0 15 m s and traces a path roughly coast to 200 lon offshore the southern california coastline has a parallel to the california baja california coastline localized concave curvature between the headland at point conception to measurements of flow can exceed 0 5 m s davis 19851 an the u s mexican border as a whole this region is referred to as instantaneous realization of the cc includes a tangle of meanders the california bight the geographic bathymetric dguration eddies and narrow jetlike flows and counterllows the cc lies at of the bight exm a pronounced influence upon the local circula varying distances off the coast and at the latitude of the tion patterns and heme upon the distributions of physical e u s mexican border there is a strong shoreward component to sverdrup and fleming 19411 and biological quantities e g the flow in most seasons especially summa the flow splits one allen 1945 owen 19801 during 1985 we conducted an oceano branch turns and flows northward into the california bight graphic survey off southern california the sampling grid was becoming the eastern limb of a cyclonic eddy centered about the designed to reveal the mumce of the geographic bathymetric offshore banks seasonally fall and winter a weak inshore features upon the circulation of the california current system countercurrent ic develops at the surface along various portion6 ccs especially the flow of the california undercurrent cu of the coastline reid et d 19581 at depth the cu cdes the survey grid also includes station lines mss the core of the waters of subtropical origin poleward along the continental slope california current cc and transects an offshore dipole eddy these waters are relatively warm and saline and have low mm simpson and lym this issue the station grid of this study trations of dissolved oxygen the cu also demonstrates a welldiffers considerably from that used by the california cooperative defined seasonality and at times opposes the overlying dace oceanic fisheries investigations calcofi surveys in both its flow maps and sections of the long term seasonal means of relaspatial resolution and depth of sampling the objectives of thic tive geostrophic velocity and distributions of ocean characteristics report are 1 to examine the spatial continuity of the cu through for the ccs are available in calcofi atlas 30 lym et d 19821 the complex bathymeny of the bight 2 to trace the poleward for a comprehensive review of the long term seasonal large scale paths and offshore spread of waters of southern origin transported description of the ccs the readex is referred to recent papas by by the cu 3 to contrast this subsurface flow with the surface hickey 1979 chelton 19841 and lynn andslnpsm 19871 and flow and 4 to compare these results with the long term calcofi to important references of pioneering work given therein mean conditions

effects of the 2013 2016 northeast pacific warm anomaly on physical and biogeochemical variables off northwestern baja california derived from a numerical npzd ocean model abstract interannual climatic anomalies have important physical and biological consequences for the southern part of the california current system ccs two examples of these anomalies are the blob and el nino phenomena the blob was an anomalously warm water mass that formed in the gulf of alaska during fall 2013 and then affected most of the eastern north pacific including the waters off baja california mexico in this work we use a biogeochemical nutrient phytoplankton zooplankton detritus npzd model coupled to a three dimensional hydrodynamic model which allowed the simulation of some of the physical and biological consequences of the anomalous warm 2013 2016 period the blob was observed in 2014 and el nino by mid 2015 a model observation comparison showed that in some cases the model solution deviates substantially from the observed vertical thermal structure but the temporal evolution of the spatially averaged variables diagnosed by the model shows good agreement with the observations except for the period from late 2015 to mid 2016 when the sea surface temperature sst is underestimated and the model failed to reproduce the correct sign of the surface chlorophyll a schl anomalies an eof analysis of the 15 year 2003 2017 record of monthly mean modeled variables allowed the identification of two main contributions to the model variability one mode mostly correlated with the multivariate el nino southern oscillation enso index mei explaining 50 of the variance of temperature t and dissolved nitrogen n and 10 of the variance of chlorophyll a chl and another mode mostly correlated with the coastal upwelling index cui anomaly explaining 50 70 of variance of chl and only 10 20 of variance of t and n in the 2013 2016 period an el nino signal diagnosed by the mei induced a remarkable warming off northwestern baja california as a consequence the thermocline and the nutricline deepened during this period and caused a deepening and weakening of the subsurface chl maximum scm around the southern region of the study area near punta baja these effects were more intense at the surface over the shelf but in the northern region south of southern california bight the effects were more intense subsurface seaward of the shelf break this enso modulated subsurface warming tends to weaken the southern california eddy during el nino events and intensify it during la nina episodes during the 2013 2015 period there was also a weakening of the upwelling favorable winds which caused a prolonged negative anomaly of the wind forcing reducing the nutrient flux and causing negative chl anomalies finally in addition to the partial relation between the enso and the warming observed along the baja california coast the anomalies were observed in this area 4 6 months before the onset of the el nino conditions mei 0 5 period when the blob was affecting the southern part of the ccs

pacific sea surface temperature and the winter of 2014 it is shown from historical data and from modeling experiments that a proximate cause of the cold winter in north america in 2013 2014 was the pattern of sea surface temperature sst in the pacific ocean each of the three dominant modes of sst variability in the pacific is connected to the tropics and has a strong expression in extratropical sst and weather patterns beginning in the middle of 2013 the third mode of sst variability was two standard deviations positive and has remained so through january 2015 this pattern is associated with high pressure in the northeast pacific and low pressure and low surface temperatures over central north america a large ensemble of model experiments with observed ssts confirms that sst anomalies contributed to the anomalous winter of 2014

underwater gliders reveal rapid arrival of el nino effects off california s coast 1 the 2009 2010 el nino marked the first occurrence of this climate phenomenon since the initiation of sustained autonomous glider surveillance in the california current system ccs spray glider observations reveal the subsurface effects of el nino in the ccs with spatial and temporal resolutions that could not have been obtained practically with any other observational method glider observations show that upper ocean waters in the ccs were unusually warm and isopycnals were abnormally deep during the el nino event but indicate no anomalous water masses in the region observed oceanic anomalies in the ccs are nearly in phase with an equatorial el nino index and local anomalies of atmospheric forcing these observations point toward an atmospheric teleconnection as an important mechanism for the 2009 2010 el nino s remote effect on the midlatitude ccs

interdecadal variability of the pacific ocean model response to observed heat flux and wind stress anomalies variability of the pacific ocean is examined in numerical simulations with an ocean general circulation model forced by observed anomalies of surface heat flux wind stress and turbulent kinetic energy tke over the period 1970 88 the model captures the 1976 77 winter time climate shift in sea surface temperature as well as its monthly seasonal and longer term variability as evidenced in regional time series and empirical orthogonal function analyses examination of the surface mixed layer heat budget reveals that the 1976 77 shift was caused by a unique concurrance of sustained heat flux input anomalies and very strong horizontal advection anomalies during a multi month period preceding the shift in both the central pacific region where cooling occurred and the california coastal region where warming occurred in the central pacific the warm conditions preceding and the cold conditions following the shift tend to be maintained by anomalous vertical mixing due to increases in the atmospheric momentum flux tke input into the mixed layer which deepens in the model after the shift from the early 1970s to the late 1970s and 1980s since the ocean model does not contain feedback to the atmosphere and it succeeds in capturing the major features of the 1976 77 shift it appears that the midlatitude part of the shift was driven by the atmosphere although effects of midlatitude ocean atmosphere feedback are still possible the surface mixed layer heat budget also reveals that in the central pacific the effects of heat flux input and vertical mixing anomalies are comparable in amplitude while horizontal advection anomalies are roughly half that size in the california coastal region in contrast where wind variability is much weaker than in the central pacific horizontal advection and vertical mixing effects on the mixed layer heat budget are only one quarter the size of typical heat flux input anomalies

causality of an extreme harmful algal bloom in monterey bay california during the 2014 2016 northeast pacific warm anomaly an ecologically and economically disruptive harmful algal bloom hab affected much of the northeast pacific margin in 2015 during a prolonged oceanic warm anomaly caused by diatoms of the genus pseudo nitzschia this hab produced the highest particulate concentrations of the biotoxin domoic acid da ever recorded in monterey bay california bloom inception followed strong upwelling during the spring transition which introduced nutrients and eliminated the warm anomaly locally subsequently moderate and intermittent upwelling created favorable conditions for growth and accumulation of hab biomass which was dominated by a highly toxigenic species p australis high cellular da concentrations were associated with available nitrogen for da synthesis coincident with silicate exhaustion this nutrient influence resulted from two factors 1 disproportionate depletion of silicate in upwelling source waters during the warm anomaly the most severe depletion observed in 24 years and 2 silicate uptake by the dense diatom bloom

detection of the fast kelvin wave teleconnection due to el nino southern oscillation previous analyses of the ocean state along the western american coast have often indicated unexpectedly slow and limited propagation of coastally trapped kelvin waves associated with the e1 nifio southern oscillation in contrast theoretical and numerical ocean models demonstrate that these kelvin waves are a rapid and long range teleconnection between the low and high latitude pacific ocean strongly impacting both the surface coastal currents and nutrient upwelling sea level variations along the western coast of north america are reexamined under the assumption that tropically forced kelvin waves are produced in bursts of several months duration a cross correlation analysis restricted to mid 1982 to mid 1983 is performed between galapagos island and stations along western central and north america a coastally trapped kelvin wave is revealed to propagate at a speed of 2 3 m s from the tropical pacific to the aleutian island chain the observed phase speed agrees with the estimated speed of a kelvin wave based on the average density profile of the ocean near the coast weakere1 nifio events in 1986 1987 and 1991 1992 appear to contain a combination of this remotsignal and local wind forcing the wave propagation speed calculated from the spectrhl phase is shown to be sensitive to the presence of other noise processes in the observations this is demonstrated through an analysis of a synthetic sea level data set that contains many of the essential features of the real sea level data a relatively small level of red noise can give a 100 expected error in the estimated propagation speed this suggests a new explanation for this important inconsistency within dynamical oceanography

linking the tropical northern hemisphere pattern to the pacific warm blob and atlantic cold blob abstractduring 2013 15 prolonged near surface warming in the northeastern pacific was observed and has been referred to as the pacific warm blob here statistical analyses are conducted to show that the generation of the pacific blob is closely related to the tropical northern hemisphere tnh pattern in the atmosphere when the tnh pattern stays in its positive phase for extended periods of time it generates prolonged blob events primarily through anomalies in surface heat fluxes and secondarily through anomalies in wind induced ocean advection five prolonged 24 months blob events are identified during the past six decades 1948 2015 and the tnh blob relationship can be recognized in all of them although the pacific decadal oscillation and el nino can also induce an arc shaped warming pattern near the pacific blob region they are not responsible for the generation of pacific blob events the essential feature of pacific blob generation is the tnh forced gulf of alaska warming pattern this stu

atmospheric forcing of interannual variability in the northeast pacific ocean connections with el nino the nature and causes of the observed interannual variability of oceanic conditions in the northeast pacific were investigated using a variety of meteorological and oceanographic data sets an examination of a long series of seasonal mean atmospheric sea level pressure slp charts showed that when the winter average slp pattern in the north pacific varies significantly from climatology it tends to do this in one of two characteristic ways in particular in some winters there is an anomalously strong circulation which differs from climatology mainly in having an intensified aleutian low in other winters there is an anomalously weak atmospheric circulation this is almost invariably associated with the westward displacement of the aleutian low and the production of a separate but much weaker low in the gulf of alaska the north pacific winter slp appears to have some relation to the southern oscillation so and oceanic temperatures in the tropics in particular el nino southern oscillation enso episodes are generally coincident with strong north pacific slp patterns and often follow winters with weak slp patterns however this relationship is far from being perfectly regular and predictable interannual variations in the intensity of the north pacific atmospheric surface circulation were found to be strongly correlated with the anomalies of both sea surface temperature sst and sea level height slh at stations along the british columbia coast an intense aleutian low is invariably associated with warm coastal waters and high coastal sea levels by comparing a large number of pacific slp and sst maps it was possible to verify that the relation between north pacific slp and oceanic surface temperature actually applies to the sst over much of the northeast pacific at least as far west as 150 w the relationship of north pacific slp with the so together with the relationship between north pacific slp and oceanic conditions in the northeast pacific can account for the observed general tendency for sst and slh along the west coast of north america to be anomalously high during tropical enso episodes on the other hand the lack of a truly predictable relation between the southern oscillation and north pacific slp explains the fact that not all enso events are associated with wanning of the northeast pacific