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Sample records for atlantic north america

  1. Genetic structure of avian influenza viruses from ducks of the Atlantic flyway of North America.

    Directory of Open Access Journals (Sweden)

    Yanyan Huang

    Full Text Available Wild birds, including waterfowl such as ducks, are reservoir hosts of influenza A viruses. Despite the increased number of avian influenza virus (AIV genome sequences available, our understanding of AIV genetic structure and transmission through space and time in waterfowl in North America is still limited. In particular, AIVs in ducks of the Atlantic flyway of North America have not been thoroughly investigated. To begin to address this gap, we analyzed 109 AIV genome sequences from ducks in the Atlantic flyway to determine their genetic structure and to document the extent of gene flow in the context of sequences from other locations and other avian and mammalian host groups. The analyses included 25 AIVs from ducks from Newfoundland, Canada, from 2008-2011 and 84 available reference duck AIVs from the Atlantic flyway from 2006-2011. A vast diversity of viral genes and genomes was identified in the 109 viruses. The genetic structure differed amongst the 8 viral segments with predominant single lineages found for the PB2, PB1 and M segments, increased diversity found for the PA, NP and NS segments (2, 3 and 3 lineages, respectively, and the highest diversity found for the HA and NA segments (12 and 9 lineages, respectively. Identification of inter-hemispheric transmissions was rare with only 2% of the genes of Eurasian origin. Virus transmission between ducks and other bird groups was investigated, with 57.3% of the genes having highly similar (≥99% nucleotide identity genes detected in birds other than ducks. Transmission between North American flyways has been frequent and 75.8% of the genes were highly similar to genes found in other North American flyways. However, the duck AIV genes did display spatial distribution bias, which was demonstrated by the different population sizes of specific viral genes in one or two neighbouring flyways compared to more distant flyways.

  2. Campanian Climatic Change: Isotopic Evidence from Far East, North America, North Atlantic and Western Europe

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Paleoclimatic settings have been reconstructed for the Campanian using original oxygenisotopic analyses of well-preserved molluskan and foraminifera shells from Russian Far East,Hokkaido, USA, Belgium and some DSDP holes (95, 98, 102, 390A, and 392A) in North Atlantic. Early Early Campanian climatic optimum has been recognized from data on high bottom shelf water paleotemperatures in middle latitudes of both the western circum-Pacific (to 24.2℃) and the eastern circum-Pacific (to 26.4℃) areas and high bottom shallow water paleotemperatures in high latitudes of the Koryak Upland (22.4-25.5℃), which agrees with the data on the Campanian Barykovskaya flora in high latitudes (Golovneva and Herman, 1998) and Jonker flora and its equivalents in middle latitudes. Judging from the data on comparatively high bottom shallow water paleotemperature values in high latitudes, South Alaska (19.4℃) and the Koryak Upland (22.4-25.5℃), we also expect Latest Campanian temperature maximum, which has not been confirmed, however, for low and middle latitudes by neither of isotopic nor paleobotanic data now. Main climatic tendency during the Campanian (with the exception of Latest Campanian) has been learned from isotopic composition of Campanian aragonitic ammonoid shells from the Hokkaido-South Sakhalin (Krilyon) marine basin.In contrary to Huber's et al. (2002) assumption, we expect warm greenhouse conditions during the most part of the Campanian.

  3. Deriving long-term sea level variations at tide gauge stations in Atlantic North America

    Science.gov (United States)

    Ince, E. S.; Sideris, M. G.; Rangelova, E.

    2009-05-01

    Tide gauge recording is an indispensable geodetic tool to study local sea level variations in coastal areas and mean sea level trends on a global scale. Combined with satellite altimetry sea surface heights or GNSS- derived ellipsoidal heights, tide gauge records have been used for deriving estimates of vertical crustal motion elsewhere. The objective of our paper is to study the capabilities of the method of singular spectrum analysis, which is generically related to empirical orthogonal functions/principal component analysis technique, to derive local long-term and secular sea level trends. This method allows one to extract any anomalous sea level signals, which is difficult to achieve by the conventional harmonic analysis. We use a set of tide gauge stations in Atlantic Canada and the USA extracted from the monthly PSMSL data base. To create continuous time series, we fill all time gaps by interpolating the main periodic and trend components of the sea level signal using the least squares harmonic analysis. We analyze all tide gauge time series simultaneously through singular value decomposition of the time-lagged series combined in a data trajectory matrix. This enables us to extract and separate the main modes of variability of the local sea level and to study only the long-term spatio-temporal patterns in the sea level variations. Our preliminary results show that the length of the tide gauge time series and the relative contribution of the signals to the total sea level variance are the two crucial factors that may preclude the separation of the local secular sea level fall or rise from any decadal sea level variability. The outcome of our study will be useful for combined satellite altimetry/TG/GRACE studies of sea level changes in the coastal areas, studies of vertical crustal motion due to postglacial rebound in the region, as well as the definition and realization of a dynamic reference surface for orthometric heights in North America.

  4. Upper Mantle Discontinuity Structure Beneath the Western Atlantic Ocean and Eastern North America from SS Precursors

    Science.gov (United States)

    Schmerr, N. C.; Beghein, C.; Kostic, D.; Baldridge, A. M.; West, J. D.; Nittler, L. R.; Bull, A. L.; Montesi, L.; Byrne, P. K.; Hummer, D. R.; Plescia, J. B.; Elkins-Tanton, L. T.; Lekic, V.; Schmidt, B. E.; Elkins, L. J.; Cooper, C. M.; ten Kate, I. L.; Van Hinsbergen, D. J. J.; Parai, R.; Glass, J. B.; Ni, J.; Fuji, N.; McCubbin, F. M.; Michalski, J. R.; Zhao, C.; Arevalo, R. D., Jr.; Koelemeijer, P.; Courtier, A. M.; Dalton, H.; Waszek, L.; Bahamonde, J.; Schmerr, B.; Gilpin, N.; Rosenshein, E.; Mach, K.; Ostrach, L. R.; Caracas, R.; Craddock, R. A.; Moore-Driskell, M. M.; Du Frane, W. L.; Kellogg, L. H.

    2015-12-01

    Seismic discontinuities within the mantle arise from a wide range of mechanisms, including changes in mineralogy, major element composition, melt content, volatile abundance, anisotropy, or a combination of the above. In particular, the depth and sharpness of upper mantle discontinuities at 410 and 660 km depth are attributed to solid-state phase changes sensitive to both mantle temperature and composition, where regions of thermal heterogeneity produce topography and chemical heterogeneity changes the impedance contrast across the discontinuity. Seismic mapping of this topography and sharpness thus provides constraint on the thermal and compositional state of the mantle. The EarthScope USArray is providing unprecedented access to a wide variety of new regions previously undersampled by the SS precursors. This includes the boundary between the oceanic plate in the western Atlantic Ocean and continental margin of eastern North America. Here we use a seismic array approach to image the depth, sharpness, and topography of the upper mantle discontinuities, as well as other possible upper mantle reflectors beneath this region. This array approach utilizes seismic waves that reflect off the underside of a mantle discontinuity and arrive several hundred seconds prior to the SS seismic phase as precursory energy. In this study, we collected high-quality broadband data SS precursors data from shallow focus (4th root vespagrams to enhance the SS precursors and determine how they sample the mantle. Our data show detection of localized structure on the discontinuity boundaries as well as additional horizons, such as the X-discontinuity and a potential reflection from a discontinuity near the depth of the lithosphere-asthenosphere boundary. These structures are related to the transition from predominantly old ocean lithosphere to underlying continental lithosphere, as while deeper reflectors are associated with the subduction of the ancient Farallon slab. A comparison of the

  5. Role of convection in redistributing formaldehyde to the upper troposphere over North America and the North Atlantic during the summer 2004 INTEX campaign

    OpenAIRE

    Fried, Alan; Olson, Jennifer R; Walega, James G.; Crawford, Jim H; Chen, Gao; Weibring, Petter; Richter, Dirk; Roller, Chad; Tittel, Frank; Porter, Michael; Fuelberg, Henry; Halland, Jeremy; Bertram, Timothy H; Cohen, Ronald C.; Pickering, Kenneth

    2008-01-01

    Measurements of formaldehyde (CH2O) from a tunable diode laser absorption spectrometer (TDLAS) were acquired onboard the NASA DC-8 aircraft during the summer 2004 INTEX-NA campaign to test our understanding of convection and CH2O production mechanisms in the upper troposphere (UT, 6–12 km) over continental North America and the North Atlantic Ocean. The present study utilizes these TDLAS measurements and results from a box model to (1) establish sets of conditions by which to distinguish “bac...

  6. Hotspot of accelerated sea-level rise on the Atlantic coast of North America

    Science.gov (United States)

    Sallenger,, Asbury H., Jr.; Doran, Kara S.; Howd, Peter A.

    2012-01-01

    Climate warming does not force sea-level rise (SLR) at the same rate everywhere. Rather, there are spatial variations of SLR superimposed on a global average rise. These variations are forced by dynamic processes, arising from circulation and variations in temperature and/or salinity, and by static equilibrium processes, arising from mass redistributions changing gravity and the Earth's rotation and shape. These sea-level variations form unique spatial patterns, yet there are very few observations verifying predicted patterns or fingerprints. Here, we present evidence of recently accelerated SLR in a unique 1,000-km-long hotspot on the highly populated North American Atlantic coast north of Cape Hatteras and show that it is consistent with a modelled fingerprint of dynamic SLR. Between 1950–1979 and 1980–2009, SLR rate increases in this northeast hotspot were ~ 3–4 times higher than the global average. Modelled dynamic plus steric SLR by 2100 at New York City ranges with Intergovernmental Panel on Climate Change scenario from 36 to 51 cm (ref. 3); lower emission scenarios project 24–36 cm (ref. 7). Extrapolations from data herein range from 20 to 29 cm. SLR superimposed on storm surge, wave run-up and set-up will increase the vulnerability of coastal cities to flooding, and beaches and wetlands to deterioration.

  7. North Atlantic Temperature Anomaly

    OpenAIRE

    Vukcevic, M.A.

    2009-01-01

    The author postulates the existence of a high correlation between North Atlantic Temperature Anomaly and the variations of magnetic field over the Hudson Bay region. Post-glacial uplift and convection in the underlying mantle uplift (as reflected in changes of the area's magnetic intensity) are making significant contribution to the Atlantic basin climate change.

  8. Subsidence along the Atlantic Coast of North America: Insights from GPS and late Holocene relative sea level data

    Science.gov (United States)

    Karegar, Makan A.; Dixon, Timothy H.; Engelhart, Simon E.

    2016-04-01

    The Atlantic Coast of North America is increasingly affected by flooding associated with tropical and extratropical storms, exacerbated by the combined effects of accelerated sea-level rise and land subsidence. The region includes the collapsing forebulge of the Laurentide Ice Sheet. High-quality records of late Holocene relative sea-level (RSL) rise are now available, allowing separation of long-term glacial isostatic adjustment-induced displacement from modern vertical displacement measured by GPS. We compare geological records of late Holocene RSL to present-day vertical rates from GPS. For many coastal areas there is no significant difference between these independent data. Exceptions occur in areas of recent excessive groundwater extraction, between Virginia (38°N) and South Carolina (32.5°N). The present-day subsidence rates in these areas are approximately double the long-term geologic rates, which has important implications for flood mitigation. Tide gauge records, therefore, should be used with caution for studying sea-level rise in this region.

  9. The Role of Convection in Redistributing Formaldehyde to the Upper Troposphere Over North America and the North Atlantic during the Summer 2004 INTEX Campaign

    Science.gov (United States)

    Fried, Alan; Olson, Jennifer R.; Walega, Jim; Crawford, Jim H.; Chen, Gao; Weibring, Petter; Richter, Dirk; Roller, Chad; Tittel, Frank; Porter, Michael; Fuelberg, Henry; Halland, Jeremy; Bertram, Timothy H.; Cohen, Ronald C.; Pickering, Kenneth; Heikes, Brian G.

    2007-01-01

    Measurements of CH2O from a tunable diode laser absorption spectrometer (TDLAS) were acquired onboard the NASA DC-8 during the summer 2004 INTEX-NA (Intercontinental Chemical Transport Experiment - North America) campaign to test our understanding of convection and production mechanisms in the upper troposphere (UT, 6-12-km) over continental North America and the North Atlantic Ocean. Point-by-point comparisons with box model calculations, when MHP (CH3OOH) measurements were available for model constraint, resulted in a median CH2O measurement/model ratio of 0.91 in the UT. Multiple tracers were used to arrive at a set of UT CH2O background and perturbed air mass periods, and 46% of the TDLAS measurements fell within the latter category. At least 66% to 73% of these elevated UT observations were caused by enhanced production from CH2O precursors rather than direct transport of CH2O from the boundary layer. This distinction is important, since the effects from the former can last for over a week or more compared to one day or less in the case of convective transport of CH2O itself. In general, production of CH2O from CH4 was found to be the dominant source term, even in perturbed air masses. This was followed by production from MHP, methanol, PAN type compounds, and ketones, in descending order of their contribution. In the presence of elevated NO from lightning and potentially from the stratosphere, there was a definite trend in the CH2O discrepancy, which for the highest NO mixing ratios produced a median CH2O measurement/model ratio of 3.9 in the 10-12-km range. Discrepancies in CH2O and HO2 in the UT with NO were highly correlated and this provided further information as to the possible mechanism(s) responsible. These discrepancies with NO are consistent with additional production sources of both gases involving CH3O2 + NO reactions, most likely caused by unmeasured hydrocarbons.

  10. The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

    Directory of Open Access Journals (Sweden)

    M. Parrington

    2012-02-01

    Full Text Available We have analysed the sensitivity of the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model and observations from in situ and satellite instruments. We show that the model ozone distribution is consistent with observations from the Pico Mountain Observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES and Infrared Atmospheric Sounding Instrument (IASI satellite instruments. Mean biases between the model and observed ozone mixing ratio in the free troposphere were less than 10 ppbv. We used the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in the eastern US and south-eastern Canada. We also used the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT satellite instrument. The CO inversion showed that, on average, the FLAMBE emissions needed to be reduced to 89% of their original values, with scaling factors ranging from 12% to 102%, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as −20 ppbv, −50 pptv, and −20 pptv respectively. The modification of the biomass burning emission estimates reduced the model ozone distribution by approximately −3 ppbv (−8% and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere

  11. Piscine Orthoreovirus from Western North America Is Transmissible to Atlantic Salmon and Sockeye Salmon but Fails to Cause Heart and Skeletal Muscle Inflammation.

    Science.gov (United States)

    Garver, Kyle A; Johnson, Stewart C; Polinski, Mark P; Bradshaw, Julia C; Marty, Gary D; Snyman, Heindrich N; Morrison, Diane B; Richard, Jon

    2016-01-01

    Heart and skeletal muscle inflammation (HSMI) is a significant and often fatal disease of cultured Atlantic salmon in Norway. The consistent presence of Piscine orthoreovirus (PRV) in HSMI diseased fish along with the correlation of viral load and antigen with development of lesions has supported the supposition that PRV is the etiologic agent of this condition; yet the absence of an in vitro culture system to demonstrate disease causation and the widespread prevalence of this virus in the absence of disease continues to obfuscate the etiological role of PRV with regard to HSMI. In this study, we explore the infectivity and disease causing potential of PRV from western North America-a region now considered endemic for PRV but without manifestation of HSMI-in challenge experiments modeled upon previous reports associating PRV with HSMI. We identified that western North American PRV is highly infective by intraperitoneal injection in Atlantic salmon as well as through cohabitation of both Atlantic and Sockeye salmon. High prevalence of viral RNA in peripheral blood of infected fish persisted for as long as 59 weeks post-challenge. Nevertheless, no microscopic lesions, disease, or mortality could be attributed to the presence of PRV, and only a minor transcriptional induction of the antiviral Mx gene occurred in blood and kidney samples during log-linear replication of viral RNA. Comparative analysis of the S1 segment of PRV identified high similarity between this North American sequence and previous sequences associated with HSMI, suggesting that factors such as viral co-infection, alternate PRV strains, host condition, or specific environmental circumstances may be required to cause this disease. PMID:26730591

  12. Piscine Orthoreovirus from Western North America Is Transmissible to Atlantic Salmon and Sockeye Salmon but Fails to Cause Heart and Skeletal Muscle Inflammation.

    Directory of Open Access Journals (Sweden)

    Kyle A Garver

    Full Text Available Heart and skeletal muscle inflammation (HSMI is a significant and often fatal disease of cultured Atlantic salmon in Norway. The consistent presence of Piscine orthoreovirus (PRV in HSMI diseased fish along with the correlation of viral load and antigen with development of lesions has supported the supposition that PRV is the etiologic agent of this condition; yet the absence of an in vitro culture system to demonstrate disease causation and the widespread prevalence of this virus in the absence of disease continues to obfuscate the etiological role of PRV with regard to HSMI. In this study, we explore the infectivity and disease causing potential of PRV from western North America-a region now considered endemic for PRV but without manifestation of HSMI-in challenge experiments modeled upon previous reports associating PRV with HSMI. We identified that western North American PRV is highly infective by intraperitoneal injection in Atlantic salmon as well as through cohabitation of both Atlantic and Sockeye salmon. High prevalence of viral RNA in peripheral blood of infected fish persisted for as long as 59 weeks post-challenge. Nevertheless, no microscopic lesions, disease, or mortality could be attributed to the presence of PRV, and only a minor transcriptional induction of the antiviral Mx gene occurred in blood and kidney samples during log-linear replication of viral RNA. Comparative analysis of the S1 segment of PRV identified high similarity between this North American sequence and previous sequences associated with HSMI, suggesting that factors such as viral co-infection, alternate PRV strains, host condition, or specific environmental circumstances may be required to cause this disease.

  13. Response to “Comment on 'The transition on North America from the warm humid Pliocene to the glaciated Quaternary traced by eolian dust deposition at a benchmark North Atlantic Ocean drill site', by David Lang et al.”

    Science.gov (United States)

    Lang, David C.; Bailey, Ian; Wilson, Paul A.; Foster, Gavin L.; Bolton, Clara T.; Friedrich, Oliver; Gutjahr, Marcus

    2014-11-01

    In volume 93 of Quaternary Science Reviews we published a new record of terrigenous inputs to Integrated Ocean Drilling Program (IODP) Site U1313 that tracks the history of aeolian dust deposition in the North Atlantic Ocean and aridity on North America during the late Pliocene-earliest Pleistocene intensification of northern hemisphere glaciation (iNHG, 3.3 to 2.4 Ma). Naafs et al. (2014) are generally supportive but question one of our conclusions, specifically our argument that "glacial grinding and transport of fine grained sediments to mid latitude outwash plains is not the fundamental mechanism controlling the magnitude of the flux of higher plant leaf waxes from North America to Site U1313 during iNHG." They suggest that our argument is predominantly based on our observation that the relationship between sediment lightness (L*)-based terrigenous inputs and dust-derived biomarkers, which is observed to be linear elsewhere (Martínez-Garcia et al., 2011), is non-linear at Site U1313.

  14. Geophysical and geodynamic studies of the North Atlantic Realm

    DEFF Research Database (Denmark)

    Schiffer, Christian

    2015-01-01

    Atlantic, such as the occurrence of the Iceland Melt Anomaly and the North Atlantic Igneous Province, as well as the separation from the Jan Mayen microcontinent (P4). Finally a novel modelling approach was developed to iteratively improve predictions of the lithospheric geopotential stress field with......The geology of the North Atlantic Realm (NAR), including the North Atlantic, Greenland, the Arctic, Iceland, Scandinavia, Northern Europe and Northeast America has been studied for more than a century and inspired some of the most fundamental theories in geoscience, such as plate tectonics, the...... mountain range (approx. 425 Ma), the exact series and number of collision and subduction events as well as subduction polarity. b) The formation of the North Atlantic (approx. 60 Ma) and accompanied high magmatic activity which formed distinct and conspicuous structures and features, such as the Iceland...

  15. Anaglyph, North America

    Science.gov (United States)

    2003-01-01

    This anaglyph (stereoscopic view) of North America was generated with data from the Shuttle Radar Topography Mission (SRTM). It is best viewed at or near full resolution with anaglyph glasses. For this broad view the resolution of the data was first reduced to 30 arcseconds (about 928 meters north-south and 736 meters east-west in central North America), matching the best previously existing global digital topographic data set called GTOPO30. The data were then resampled to a Mercator projection with approximately square pixels (about one kilometer, or 0.6 miles, on each side). Even at this decreased resolution the variety of landforms comprising the North American continent is readily apparent.Active tectonics (structural deformation of the Earth's crust) along and near the Pacific North American plate boundary creates the great topographic relief seen along the Pacific coast. Earth's crustal plates converge in southern Mexico and in the northwest United States, melting the crust and producing volcanic cones. Along the California coast, the plates are sliding laterally past each other, producing a pattern of slices within the San Andreas fault system. And, where the plates are diverging, the crust appears torn apart as one huge tear along the Gulf of California (northwest Mexico), and as the several fractures comprising the Basin and Range province (in and around Nevada).Across the Great Plains, erosional patterns dominate, with stream channels surrounding and penetrating the remnants of older smooth slopes east of the Rocky Mountains. This same erosion process is exposing the bedrock structural patterns of the Black Hills in South Dakota and the Ozark Mountains in Arkansas. Lateral erosion and sediment deposition by the Mississippi River has produced the flatlands of the lower Mississippi Valley and the Mississippi Delta.To the north, evidence of the glaciers of the last ice age is widely found, particularly east of the Canadian Rocky Mountains and around the

  16. North Atlantic, ITCZ, and Monsoonal Climate Links

    Science.gov (United States)

    Haug, G. H.; Deplazes, G.; Peterson, L. C.; Brauer, A.; Mingram, J.; Dulski, P.; Sigman, D. M.

    2008-12-01

    Major element chemistry and color data from sediment cores in the anoxic Cariaco Basin off Venezuela record with (sub)annual resolution large and abrupt shifts in the hydrologic cycle of the tropical Atlantic during the last 80 ka. These data suggest a direct connection between the position of the ITCZ over northern South America, the strength of trade winds, and the temperature gradient to the high northern latitudes, ENSO, and monsoonal climate in Asia. The mechanisms behind these decadal-scale ITCZ-monsoon swings can be further explored at major climate transitions such as the onset of Younger Dryas cooling at ~12.7 ka, one of the most abrupt climate changes observed in ice core, lake and marine records in the North Atlantic realm and much of the Northern Hemisphere. Annually laminated sediments from ideally record the dynamics of abrupt climate changes since seasonal deposition immediately responds to climate and varve counts accurately estimate the time of change. We compare sub-annual geochemical data from a lake in Western Germany, which provides one of the best-dated records currently available for this climate transition, with the new the Cariaco Basin record and a new and higher resolution record from Lake Huguang Maar in China, and the Greenland ice core record. The Lake Meerfelder Maar record indicates an abrupt increase in storminess, occurring from one year to the next at 12,678 ka BP, coincident with other observed climate changes in the region. We interpret this shift of the wintertime winds to signify an abrupt change in the North Atlantic westerlies to a stronger and more zonal jet. The observed wind shift provides the atmospheric mechanism for the strong temporal link between North Atlantic overturning and European climate during the last deglaciation, tightly coupled to ITCZ migrations observed in the Cariaco Basin sediments, and a stronger east Asian Monsoon winter monsoon as seen in lake Huguang Maar, when cave stalagmite oxygen isotope data

  17. Daucus for the flora of North America

    Science.gov (United States)

    The Flora of North America Project will treat more than 20,000 species of plants native or naturalized in North America north of Mexico, about 7% of the world's total. This contribution presents a floristic account of the two species of wild carrots (Daucus) occurring in North America, Daucus carota...

  18. Structure and functional characteristics of the meiofauna community in highly unstable intertidal mudbanks in Suriname and French Guiana (North Atlantic coast of South America)

    Science.gov (United States)

    Christine, Dupuy; Hien, Nguyen Thanh; David, Mizrahi; Jérôme, Jourde; Martine, Bréret; Hélène, Agogué; Laureen, Beaugeard; Pierrick, Bocher

    2015-11-01

    The North Atlantic coast of South America is influenced by the Amazon River. This coast is considered the muddiest in the world due to the enormous suspended sediment input from the Amazon River. The mobility of the sediment imposes a geomorphological dynamic with a rapid change of shoreline and fast alternation of facies types of the sediment. This study first describes the spatial and functional structure of meiofauna communities of highly unstable intertidal flats along coasts of French Guiana and Suriname in relation to environmental variables. Six sampling sites, composed mainly of muddy sediment, were located 700 km (Kourou) to 1200 km (Nickerie) from the mouth of the Amazon River. The granulometry, chlorophyll a biomass, prokaryote abundance, percentage of organic matter, meiofauna abundance and feeding guilds of nematodes in sediment stations were independent of the distance of the Amazon River mouth and likely were more influenced by the local dynamism of migration of mudbanks. Meiofauna was not more abundant when the sediment was dominated by the finest sediment particles and also when chlorophyll a and prokaryotes, potential prey of meiofauna, were greater. However, as a percentage, small nematodes (biomass of 0.07±0.001 μg ind-1), which are mainly epigrowth-feeders, were more abundant in very fluid mud. Local granulometry and organic matter content appeared to be driving factors of the size structure and functional characteristics of nematodes. Despite the high instability of mudflats, chlorophyll a biomass and meiofauna abundance always tended to be higher toward other world areas. No foraminifera among the six stations of the study were found. Very fluid mud with physical instability of sediment caused a large perturbation to the settlement of meiofauna; the least amounts of chlorophyll a biomass and prokaryotic and meiofauna abundances were found there. Thus, the probable mobility of sediment may select for smaller meiobenthic organisms, mainly

  19. Geographic distribution and dispersal of normapolles genera in North America

    Science.gov (United States)

    Tschudy, R.H.

    1981-01-01

    Normapolles pollen have been found in North America in Cretaceous and Lower Tertiary rocks from the eastern Atlantic Seaboard, the Mississippi embayment region and from the states and provinces from western North America as far north as the District of Mackenzie, Northwest Territories. Previous postulates relating to the Normapolles floral province (western Europe-eastern North America) were re-examined in the light of new finds of Normapolles genera in rocks from west of the Cretaceous epeiric seaway which separated the Normapolles province from the western North American Aquilapollenites province. A study of published occurrences of Normapolles genera and U.S. Geological Survey Denver Laboratory Normapolles records revealed that of the approximately 60 Normapolles genera recognized from western Europe, only 26 of these have been recognized from eastern North America. These data suggest that Normapolles-producing plants originated in western Europe and migrated to eastern North America prior to the opening of the north Atlantic seaway. Ten of these 26 genera also have been found in rocks from west of the Cretaceous epeiric seaway, suggesting that these genera were the only ones able to cross this barrier. At least six genera having Normapolles characteristics occur in eastern North America but have not yet been recorded from Europe. Two additional genera with Normapolles characteristics have been reported only from the Aquilapollenites province of western North America. Several discrepancies in the record need resolution, such as the latitudinal restriction of Thomsonipollis and Nudopollis to areas south 40??N latitude, the absence of records of Thomsonipollis east and north of central Georgia, and the absence of records of Kyandopollenites and Choanopollenites west of eastern Texas. These data show that the known boundaries of the Normapolles province are somewhat hazy and that firm conclusions regarding the geographic distribution and history of dispersal of

  20. Mosques in North America

    Directory of Open Access Journals (Sweden)

    Omar Khalidi

    2008-12-01

    Full Text Available The following article derived from an exhibit catalogue put together by Public Affairs Germany in the U.S. Embassy in Berlin and the U.S. Consulates in Frankfurt and Düsseldorf and accompanied Dr. Omar Khalidi’s photo exhibit “Mosques in America.” There are over 2,000 mosques in the United States, mostly housed in buildings originally built for other purposes. American mosques built in the last few decades, however, in the period in which Islam has begun to feel at home in the United States, are almost universally architect-designed.

  1. North Atlantic Coastal Plain aquifer system

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the North Atlantic Coastal Plain aquifer system in North Carolina, Virginia, Maryland, Deleware, and New Jersey.

  2. 22 CFR 120.31 - North Atlantic Treaty Organization.

    Science.gov (United States)

    2010-04-01

    ... DEFINITIONS § 120.31 North Atlantic Treaty Organization. North Atlantic Treaty Organization (NATO) is..., France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, The Netherlands,...

  3. Heart Failure in North America

    OpenAIRE

    Blair, John E.A.; Huffman, Mark; Shah, Sanjiv J.

    2013-01-01

    Heart failure is a major health problem that affects patients and healthcare systems worldwide. Within the continent of North America, differences in economic development, genetic susceptibility, cultural practices, and trends in risk factors and treatment all contribute to both inter-continental and within-continent differences in heart failure. The United States and Canada represent industrialized countries with similar culture, geography, and advanced economies and infrastructure. During t...

  4. Heart failure in North America.

    Science.gov (United States)

    Blair, John E A; Huffman, Mark; Shah, Sanjiv J

    2013-05-01

    Heart failure is a major health problem that affects patients and healthcare systems worldwide. Within the continent of North America, differences in economic development, genetic susceptibility, cultural practices, and trends in risk factors and treatment all contribute to both inter-continental and within-continent differences in heart failure. The United States and Canada represent industrialized countries with similar culture, geography, and advanced economies and infrastructure. During the epidemiologic transition from rural to industrial in countries such as the United States and Canada, nutritional deficiencies and infectious diseases made way for degenerative diseases such as cardiovascular diseases, cancer, overweight/obesity, and diabetes. This in turn has resulted in an increase in heart failure incidence in these countries, especially as overall life expectancy increases. Mexico, on the other hand, has a less developed economy and infrastructure, and has a wide distribution in the level of urbanization as it becomes more industrialized. Mexico is under a period of epidemiologic transition and the etiology and incidence of heart failure is rapidly changing. Ethnic differences within the populations of the United States and Canada highlight the changing demographics of each country as well as potential disparities in heart failure care. Heart failure with preserved ejection fraction makes up approximately half of all hospital admissions throughout North America; however, important differences in demographics and etiology exist between countries. Similarly, acute heart failure etiology, severity, and management differ between countries in North America. The overall economic burden of heart failure continues to be large and growing worldwide, with each country managing this burden differently. Understanding the inter-and within-continental differences may help improve understanding of the heart failure epidemic, and may aid healthcare systems in delivering

  5. Developments in Impact Assessment in North America

    Science.gov (United States)

    Beginning with a background of recent global developments in this area, this presentation will focus on how global research has impacted North America and how North America is providing additional developments to address the issues of the global economy. Recent developments inc...

  6. Nitrous oxide in the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    S. Walter

    2006-01-01

    Full Text Available In order to get a comprehensive picture of the distribution of nitrous oxide (N2O in the North Atlantic Ocean, measurements of dissolved nitrous oxide were made during three cruises in the tropical, subtropical and cold-temperate North Atlantic Ocean in October/November 2002, March/April 2004, and May 2002, respectively. To account for the history of atmospheric N2O, we suggest a new depth-dependent calculation of excess N2O (ΔN2O. N2O depth profiles showed supersaturation throughout the water column with a distinct increasing trend from the cold-temperate to the tropical region. Lowest nitrous oxide concentrations, near equilibrium and with an average of 11.0±1.7 nmol L−1, were found in the cold-temperate North Atlantic where the profiles showed no clear maxima. Highest values up to 37.3 nmol L−1 occurred in the tropical North Atlantic with clear maxima at approximately 400 m. A positive correlation of nitrous oxide with nitrate, as well as excess nitrous oxide with the apparent oxygen utilization (AOU, was only observed in the subtropical and tropical regions. Therefore, we conclude that the formation of nitrous oxide via nitrification occurs in the tropical region rather than in the cold-temperate region of the North Atlantic Ocean

  7. The North Atlantic Oscillation in the Atlantic-European SLP*

    OpenAIRE

    GLOWIENKA-HENSE, RITA

    2011-01-01

    An analysis of the signature of the North Atlantic Oscillation (NAO) in the Atlantic-European sea level pressure (SLP) is presented for observed (German Weather Service) and ECMWF T21 model data. The former time series consists of 1881–1984 January to December fields and the latter of 42 monthly fields from 3 permanent January simulations. The NAO is shown to be one of the dominant eigenmodes of SLP for all calendar months. A very similar NAO anomaly pattern is filtered from the T21 model dat...

  8. Bathymetry of North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Bathymetry of North America map layer shows depth ranges using colors. The image was derived from the National Geophysical Data Center?s ETOPO2 elevation data,...

  9. Nighttime Lights of North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is an image of nighttime lights for North America, including the Caribbean and most of Mexico. The data were collected in 1996 and 1997 as part of...

  10. On cold spells in North America and storminess in western Europe

    Science.gov (United States)

    Messori, Gabriele; Caballero, Rodrigo; Gaetani, Marco

    2016-06-01

    We discuss the dynamical and statistical links between cold extremes over eastern North America and storminess over western Europe, with a focus on the midlatitude jet stream, the North Atlantic Oscillation (NAO) and the Pacific-North American Pattern (PNA). The analysis is performed on the European Centre for Medium-Range Weather Forecasts 20th Century Reanalysis. The large-scale circulation associated with the cold spells corresponds to advection of cold air from the Arctic region into North America and to a very zonal and intense North Atlantic jet, shifted persistently south of its climatological location. These features of the Atlantic jet are conducive to destructive windstorms and intense precipitation over a large part of southern and continental Europe and the British Isles. The cold spells are preceded by a negative NAO and followed by a positive PNA; however, we interpret the associated circulation anomalies as being distinct from these standard modes of climate variability.

  11. Millennial changes in North Atlantic oxygen concentrations

    Science.gov (United States)

    Hoogakker, B. A. A.; Thornalley, D. J. R.; Barker, S.

    2016-01-01

    Glacial-interglacial changes in bottom water oxygen concentrations [O2] in the deep northeast Atlantic have been linked to decreased ventilation relating to changes in ocean circulation and the biological pump (Hoogakker et al., 2015). In this paper we discuss seawater [O2] changes in relation to millennial climate oscillations in the North Atlantic over the last glacial cycle, using bottom water [O2] reconstructions from 2 cores: (1) MD95-2042 from the deep northeast Atlantic (Hoogakker et al., 2015) and (2) ODP (Ocean Drilling Program) Site 1055 from the intermediate northwest Atlantic. The deep northeast Atlantic core MD95-2042 shows decreased bottom water [O2] during millennial-scale cool events, with lowest bottom water [O2] of 170, 144, and 166 ± 17 µmol kg-1 during Heinrich ice rafting events H6, H4, and H1. Importantly, at intermediate depth core ODP Site 1055, bottom water [O2] was lower during parts of Marine Isotope Stage 4 and millennial cool events, with the lowest values of 179 and 194 µmol kg-1 recorded during millennial cool event C21 and a cool event following Dansgaard-Oeschger event 19. Our reconstructions agree with previous model simulations suggesting that glacial cold events may be associated with lower seawater [O2] across the North Atlantic below ˜ 1 km (Schmittner et al., 2007), although in our reconstructions the changes are less dramatic. The decreases in bottom water [O2] during North Atlantic Heinrich events and earlier cold events at the two sites can be linked to water mass changes in relation to ocean circulation changes and possibly productivity changes. At the intermediate depth site a possible strong North Atlantic Intermediate Water cell would preclude water mass changes as a cause for decreased bottom water [O2]. Instead, we propose that the lower bottom [O2] there can be linked to productivity changes through increased export of organic material from the surface ocean and its subsequent remineralization in the water column

  12. Two Distinct Roles of Atlantic SSTs in ENSO Variability: North Tropical Atlantic SST and Atlantic Nino

    Science.gov (United States)

    Ham, Yoo-Geun; Kug, Jong-Seong; Park, Jong-Yeon

    2013-01-01

    Two distinct roles of the Atlantic sea surface temperatures (SSTs), namely, the North Tropical Atlantic (NTA) SST and the Atlantic Nino, on the El Nino-Southern Oscillation (ENSO) variability are investigated using the observational data from 1980 to 2010 and coupled model experiments. It appears that the NTA SST and the Atlantic Nino can be used as two independent predictors for predicting the development of ENSO events in the following season. Furthermore, they are likely to be linked to different types of El Nino events. Specifically, the NTA SST cooling during February, March, and April contributes to the central Pacific warming at the subsequent winter season, while the negative Atlantic Nino event during June, July, and August contributes to enhancing the eastern Pacific warming. The coupled model experiments support these results. With the aid of a lagged inverse relationship, the statistical forecast using two Atlantic indices can successfully predict various ENSO indices.

  13. FRESHWATER SNAILS (MOLLUSCA: GASTROPODA) OF NORTH AMERICA

    Science.gov (United States)

    Freshwater gastropod mollusks are represented in North America (north of Mexico) by 15 families, 78 genera and, as treated in this manual, 499 species. They are grouped into two large subclasses, the gill-breathing, operculated Prosobranchia and the lung-breathing, non-operculate...

  14. 76 FR 14101 - Bruss North America; Russell Springs, KY; Bruss North America; Orion, MI; Amended Revised...

    Science.gov (United States)

    2011-03-15

    ... notice was published in the Federal Register on February 10, 2011 (76 FR 7590). At the request of the... Employment and Training Administration Bruss North America; Russell Springs, KY; Bruss North America; Orion... show that worker separations occurred during the relevant time period at the Orion, Michigan...

  15. 78 FR 61844 - North Atlantic Coast Comprehensive Study

    Science.gov (United States)

    2013-10-04

    ... Department of the Army; Corps of Engineers North Atlantic Coast Comprehensive Study AGENCY: Department of the... Atlantic Coast Comprehensive Study (Hurricane Sandy). The USACE is preparing a report that will be submitted to Congress in 2015. The goals of the North Atlantic Coast Comprehensive Study authorized...

  16. Rainfall variability and predictability issues for North America

    Science.gov (United States)

    Hunt, B. G.

    2016-04-01

    A multi-millennial simulation with a coupled global climatic model has been used to investigate extreme rainfall events, mainly droughts, over North America. A rainfall index, based on the US Dust Bowl region, was used to generate a time series from which the extreme events could be identified. A very wide range of drought and pluvial multiyear sequences was obtained, all attributable to internal climatic variability. This time series reproduced the basic characteristics of the corresponding observed time series. Composites of years with negative rainfall anomalies over North America from the simulation replicated the observed rainfall composite for the Dust Bowl era, both in spatial character and intensity. Examination of individual years of a simulated composite revealed not only a wide range of rainfall anomaly patterns, dominated by drought conditions, but also ENSO distributions that included El Niño events as well as the expected La Niña events. Composites for pluvial conditions over North America were associated with composited El Niño events, as expected. Correlation of the simulated Dust Bowl rainfall with global surface temperatures identified a principal connection with the ENSO region. No systematic relationship was obtained in the simulation between the Atlantic multidecadal oscillation and Dust Bowl region rainfall, with the simulated oscillation having a much more variable periodicity than that found in the limited observations. However, a marked connection was found for SST anomalies adjacent to the northeast coast of North America, but this appears to be forced by ENSO events. A scatter diagram of NINO3.4 SST anomalies with the Dust Bowl region rainfall anomalies, for observations and the simulation, revealed inconsistencies between the occurrence of an ENSO event and the "expected" rainfall anomaly. This, and other analysis, resulted in the conclusion that annual or longer term rainfall predictions over North America, with any systematic

  17. Impact of the Interdecadal Pacific Oscillation on Tropical Cyclone Activity in the North Atlantic and Eastern North Pacific

    OpenAIRE

    Wenhong Li; Laifang Li; Yi Deng

    2015-01-01

    Tropical cyclones (TCs) are among the most devastating weather systems affecting the United States and Central America (USCA). Here we show that the Interdecadal Pacific Oscillation (IPO) strongly modulates TC activity over the North Atlantic (NA) and eastern North Pacific (eNP). During positive IPO phases, less (more) TCs were observed over NA (eNP), likely due to the presence of stronger (weaker) vertical wind shear and the resulting changes in genesis potential. Furthermore, TCs over NA te...

  18. Mechanisms and predictability of North Atlantic - European Climate

    OpenAIRE

    Pohlmann, H.

    2005-01-01

    This study investigates the mechanisms of North Atlantic-European climate using atmosphere general circulation models (AGCMs). Experiments with the AGCM ECHAM4, in which the sea surface temperature (SST) forcing is restricted to either the Atlantic or the Indo-Pacific oceans, show that both oceanic regions have an influence on North Atlantic-European climate in winter. In the experiment with SST forcing restricted to the Indo-Pacific oceans the atmospheric response projects on the North Atlan...

  19. Gaz de France action in North America

    International Nuclear Information System (INIS)

    This paper describes the action of Gaz de France (GDF), a french gas utility, in North America. GDF becomes interested in north american market and its subsidiary , GDF Quebec, has taken a partnership, SOQUIP, for the establishment of a joint venture OPTIGAZ, in Quebec, which manages Pointe-du-Lac underground facility for liquefied natural gas storage. In USA, GDF has taken a share in Tejas Power Corporation (TPC) which has developed also gas underground storage facilities in Texas and in Louisiana

  20. Rat Lungworm Expands into North America

    Centers for Disease Control (CDC) Podcasts

    2016-01-21

    Emily York, integrated pest management specialist at the Sam Noble Museum of Natural History, discusses the rat lungworm expansion in North America.  Created: 1/21/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/21/2016.

  1. Chinese Studies Librarianship in North America

    Institute of Scientific and Technical Information of China (English)

    Karen T. Wei

    2004-01-01

    Although American libraries had begun collecting Chinese language materials in the 19th century, notably the United States Library of Congress in 1869, Yale in 1878, Harvard in 1879, and Berkeley in 1896, East Asian studies librarianship in North America, including China studies librarianship, was not fully developed until the 1960s. There was no formal organization that represented the interest of Chinese studies librarians because there were few of them and most of them were China scholars rather than trained librarians. More than 100 years later, the number of Chinese studies librarians in North America has increased considerably,primarily in response to the demand in the field of China studies and more recently to the needs of immigrant population and the general public who has an interest in China.This paper traces the history and growth of Chinese studies librarianship in North America, documents the development of the professional organization that represents Chinese studies librarians, and examines the training programs that prepare them for their jobs. It also attempts to propose an international exchange forum aiming to bring together Chinese studies librarians in North America and librarians in China in sharing their experience and expertise to achieve the ultimate goal of serving the users.

  2. Forest health conditions in North America

    International Nuclear Information System (INIS)

    Some of the greatest forest health impacts in North America are caused by invasive forest insects and pathogens (e.g., emerald ash borer and sudden oak death in the US), by severe outbreaks of native pests (e.g., mountain pine beetle in Canada), and fires exacerbated by changing climate. Ozone and N and S pollutants continue to impact the health of forests in several regions of North America. Long-term monitoring of forest health indicators has facilitated the assessment of forest health and sustainability in North America. By linking a nationwide network of forest health plots with the more extensive forest inventory, forest health experts in the US have evaluated current trends for major forest health indicators and developed assessments of future risks. Canada and Mexico currently lack nationwide networks of forest health plots. Development and expansion of these networks is critical to effective assessment of future forest health impacts. - The forests of North America continue to face many biotic and abiotic stressors including fragmentation, fires, native and invasive pests, and air pollution

  3. Plate tectonic reconstructions and paleogeographic maps of the central and North Atlantic oceans

    OpenAIRE

    Sibuet, Jean-Claude; Rouzo, Stephane; Srivastava, Shiri

    2012-01-01

    We have established a new plate kinematic model of the central and North Atlantic oceans between North America, Africa, Meseta, Iberia, Flemish Cap, and Galicia Bank from Late Triassic to Late Cretaceous to better understand the nature and timing of rifting of Nova Scotia and Morocco conjugate continental margins since Late Triassic. The maps of salt distributions at the Sinemurian-Pliensbachian limit (190 Ma; after salt deposition) and in middle Bajocian (170 Ma) show that an area of the Nov...

  4. Gas deregulation in North America

    International Nuclear Information System (INIS)

    Contains Executive Summary and Chapters on: The North American gas industry; Upstream deregulation in the US and Canada; Retail regulation in the US and Canada; Customer choice in Pennsylvania and Ohio; Customer choice in Massachusetts; Deregulation legislation in Georgia; US pilot programme results; The Canadian experience; Market centres, hubs and storage; Marketers and trading companies; New roles for pipelines; Mergers and Joint ventures; Opportunities in Mexico; Conclusions - the pros and cons of deregulation. (Author)

  5. Uranium resources and geology of North America

    International Nuclear Information System (INIS)

    Since about the mid seventies, the International Atomic Energy Agency has held meetings on the geology and uranium resources of different geographic regions of the world. As a continuation of this series the Technical Committee Meeting on Uranium Resources and Geology of North America was held between 1-3 September 1987 in Saskatoon, Canada. The meeting took place in the University of Saskatchewan, hosted by the Department of Geological Sciences in cooperation with the Department of Energy, Mines and Resources Canada. Thirty-six technical papers were presented to a group of over 85 participants from seven countries. These papers provided an excellent coverage of uranium occurrences and deposits and their geological framework in Canada and the USA, with analogies from other parts of the world. North America, the region dealt with in this meeting, is of eminent significance for the world's uranium production and the nuclear industry. Total WOCA U-resources according to the classification developed by the IAEA and the Nuclear Energy Agency of OECD are periodically collected by these two organisations for their report on Uranium Resources, Production and Demand. Currently total WOCA known U resources recoverable at costs of less than $130/kg U or $50/lb U3O8) amount to 3.5 million t U, of which about 25% are located in North America, while the remainder is equally divided among Africa, Australia and the rest of WOCA (Asia, Europe, South America). Refs, figs and tabs

  6. Height System Unification in North America

    Science.gov (United States)

    Sideris, Michael; Amjadiparvar, Babak

    2015-04-01

    GOCE has contributed important gravity information towards the definition and realization of the new North American height reference system. In addition to the new gravimetric geoid models based on GOCE, offsets of the classical levelling-based vertical datums in North America, namely CGVD28 in Canada and NAVD88 in the USA and Mexico, can be computed with respect to a global equipotential surface defined by means of a GOCE-based geoid. Although the two datums will eventually be replaced by a common and continent-wide vertical datum (and in fact the new Canadian height datum established in 2013 is already geoid based), their connection and unification is of great interest to the scientific and user communities. This study investigates the practical implementation of the geodetic boundary value problem (GBVP) approach as a rigorous method for unifying classical levelling-based vertical datums. The so-called indirect bias term, the effect of the GOCE geoid omission error, the effect of the systematic levelling datum errors and distortions, and the effect of the data errors on the datum unification are of great importance for the practical implementation of this approach. These factors are investigated numerically using the GNSS-levelling and tide gauge (TG) stations in Canada, the USA, Alaska, and Mexico. The results show that the indirect bias term can be omitted if a GOCE-based global geopotential model is used in geoid computation. This is significant because the omission of the indirect bias term simplifies the geoid computations as well as the linear system of equations for the estimation of datum offsets. Because of the existing systematic levelling errors and distortions in the Canadian and US levelling networks, the datum offsets are investigated in eight smaller regions along Canadian and US coastal areas instead of over the whole North American land mass. The effect of the omission error on the datum offsets decreases significantly in areas with good

  7. The enigmatic whale: the North Atlantic humpback

    Directory of Open Access Journals (Sweden)

    Tim D Smith

    2013-10-01

    Full Text Available We know more about the North Atlantic humpback whale (Megaptera novaeangliae than we do for virtually any other cetacean, yet attempts to use this information to describe the status of the populations in this ocean basin have not proven satisfactory. The North Atlantic humpback has been the subject of extensive research over the past few decades, resulting in a substantial amount of knowledge about what has proven to be a species with a very complex life history and population structure. While several population models have been developed to integrate the available information, the data overall are not well described by any of the models. This has left considerable uncertainty about population status, and has raised questions about the interpretation of some of the data. We describe 7 specific areas where puzzling or ambiguous observations have been made; these require closer attention if population status is to be determined. These areas raise several fundamental questions, including: How many breeding populations are there? How much do the populations mix on the feeding grounds? How has the distribution of animals on both feeding and breeding grounds changed? We identify additional research needed to address the 7 areas and these questions in particular, so that population status might be determined.

  8. The North Atlantic Oscillation: variability and interactions with the North Atlantic ocean and Artic sea ice

    Energy Technology Data Exchange (ETDEWEB)

    Jung, T.

    2000-07-01

    The North Atlantic oscillation (NAO) represents the dominant mode of atmospheric variability in the North Atlantic region and describes the strengthening and weakening of the midlatitude westerlies. In this study, variability of the NAO during wintertime and its relationship to the North Atlantic ocean and Arctic sea ice is investigated. For this purpose, observational data are analyzed along with integrations of models for the Atlantic ocean, Arctic sea ice, and the coupled global climate system. From a statistical point of view, the observed NAO index shows unusually high variance on interdecadal time scales during the 20th century. Variability on other time scales is consistent with realizations of random processes (''white noise''). Recurrence of wintertime NAO anomalies from winter-to-winter with missing signals during the inbetween nonwinter seasons is primarily associated with interdecadal variability of the NAO. This recurrence indicates that low-frequency changes of the NAO during the 20th century were in part externally forced. (orig.)

  9. 78 FR 36753 - North Atlantic Coast Comprehensive Study

    Science.gov (United States)

    2013-06-19

    ... Department of the Army; Corps of Engineers North Atlantic Coast Comprehensive Study AGENCY: Department of the Army, U.S. Army Corps of Engineers, DoD. ACTION: Notice of Study Initiation. SUMMARY: The Congressional.... The goals of the North Atlantic Coast Comprehensive Study authorized under the Disaster...

  10. The impact of North Atlantic sea surface temperature errors on the simulation of North Atlantic European region climate

    OpenAIRE

    Keeley, Sarah; Sutton, Rowan; Shaffrey, Len

    2012-01-01

    Current state-of-the-art climate models fail to capture accurately the path of the Gulf Stream and North Atlantic Current. This leads to a warm bias near the North American coast, where the modelled Gulf Stream separates from the coast further north, and a cold anomaly to the east of the Grand Banks of Newfoundland, where the North Atlantic Current remains too zonal in this region. Using an atmosphere-only model forced with the sea surface temperature (SST) biases in the North Atlantic, we...

  11. North America natural gas supply trends

    International Nuclear Information System (INIS)

    The paper explores (a) how much natural gas is used in North America, (b) where these supplies of gas come from, and (c) the prognosis for long-term gas supply availability in North America. Natural gas use is growing at 2.6% per year in the US and supplies in the US and Canada are growing 1.4 and 5%, respectively. More basins holding natural gas resources are proving up and developing new reserves using the latest technology and efficiency improvements which ensures longer, more reliable, flexible gas supplies for growing markets throughout the country. As more natural gas and MTBE are used in motor vehicles, (1) pollution problems from motor vehicles will decrease, (2) less oil needs to be imported, (3) more gas production leads to domestic energy jobs being created in the US in more geographic regions, and (4) the domestic economy will benefit

  12. Industry analysis certification organisations in North America

    OpenAIRE

    Kulsky, William

    2006-01-01

    Manufacturers of electrical devices in North America have traditionally been regulatory bound to demonstrate that their products comply with all applicable national standards prior to distribution or use. The means and methods available to do so have substantially changed in the last two decades. The purpose of this paper is to analyze the approach the certification industry has adopted to accommodate change and to evaluate its ability to evolve and meet foreseeable trends. The analysis will ...

  13. The EPR for North America

    International Nuclear Information System (INIS)

    As the supplier of 30 percent of the world's nuclear generating capacity, Framatome ANP, an AREVA and, Siemens company, has been a major contributor in the development of today's international fleet of nuclear power plants. Additionally, as a member of the AREVA global family of companies, Framatome ANP is a major element of the world's largest vertically integrated nuclear supplier. The EPR is the latest evolutionary pressurized water reactor design developed by Framatome ANP. The EPR benefits from the global operating experience of the international fleet of nuclear reactors. Framatome ANP is continuing to play a leadership role in the global renaissance of nuclear power. In December 2003, a Framatome ANP and Siemens consortium signed a firm price, turn-key contract with the Finnish utility TVO for an EPR to be constructed at the Olkiluoto site, In October 2004, it was announced that France would build its first EPR at the Flamanville site as a demonstration plant for a future series of advanced nuclear plants. In February 2005, Framatome ANP submitted a proposal for the supply of four EPR's in China which would be the beginning of a series of new construction in that country. Momentum is also building for new nuclear plants in Canada. Many reports in the past year, including those published by the Canadian Energy Research Institute, indicate that new electricity supplies will be required to meet the growing energy needs of Canada, especially in Ontario. The shutdown of approximately 7,000 MWe of coal-fired generation in Ontario by 2007 will further complicate the energy supply situation. Furthermore, various reports indicate as much as 24,000 MWe of new Canadian electricity generation could be required by 2020. Due to this developing potentially large electricity supply-demand imbalance, some industry officials believe the first North American order for a new nuclear plant will be placed in Canada. It is not surprising then that Framatome ANP is focusing on

  14. Modes of winter precipitation variability in the North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Zorita, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik; Saenz, J.; Fernandez, J.; Zubillaga, J. [Bilbao Univ. (Spain)

    2001-07-01

    The modes of variability of winter precipitation in the North Atlantic sector are identified by Empirical Orthogonal Functions Analysis in the NCEP/NCAR global reanalysis data sets. These modes are also present in a gridded precipitation data set over the Western Europe. The large-scale fields of atmospheric seasonal mean circulation, baroclinic activity, evaporation and humidity transport that are connected to the rainfall modes have been also analyzed in order to investigate the physical mechanisms that are causally linked to the rainfall modes. The results indicate that the leading rainfall mode is associated to the North Atlantic oscillation and represents a meridional redistribution of precipitation in the North Atlantic through displacements of the storm tracks. The second mode is related to evaporation anomalies in the Eastern Atlantic that precipitate almost entirely in the Western Atlantic. The third mode seems to be associated to meridional transport of water vapor from the Tropical Atlantic. (orig.)

  15. Fostering renewable electricity markets in North America

    International Nuclear Information System (INIS)

    This paper provided an overview of key market demand and supply drivers for the renewable electricity in Canada, the United States and Mexico. The aim of the paper was to assist North American governments in supporting the development of renewable electricity by addressing barriers that currently contribute to higher costs as well as challenges related to policy implementation. The paper outlined regulatory mandates and discussed issues related to voluntary purchases, and financial incentives. Current policy frameworks for renewable electricity were also examined. Opportunities for developing the renewable electricity market North America were explored. Wind power environmental standards were reviewed. Various green pricing schemes were discussed. The paper also included recommendations for the current electricity market as well as for members of the North American Agreement on Environmental Cooperation. 84 refs., 4 tabs., 7 figs

  16. Fostering renewable energy markets in North America

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jeremy [North American Comission for Environmental Cooperation (CEC), (United States)

    2007-06-15

    This presentation describes projects, programs and other issues addressed in order to promote renewable energy markets in North America. These are carried out by the North American Commission for Environmental Cooperation (CEC). In the first part of this presentation, there are going to be found some of the rules imposed by the North American Agreement on Environmental Cooperation (NAAEC). Then, it is shown the structure of the CEC as well as its programs, besides, there are presented the environment projects and the objectives along with their respective trades. There are described both benefits environmental and non-environmental. Also, there are shown the issues which the CEC is working in. And finally, it is shown a list mentioning the aspects that would change if: the expansion of the Mexico's Federal Commission of Electricity (CFE), happens, the grid-interconnected and the self supply of Renewable Electricity increase. [Spanish] En esta presentacion se describen los proyectos, los programas y otras cuestiones, cuyo objetivo es impulsar los mercados de energia renovable en America del Norte, realizadas por la North American Commission for Environmental Cooperation. En la primera parte, se encuentran algunas de las reglas impuestas por el Acuerdo de Cooperacion Ambiental de America del Norte (ACAAN). Enseguida, se muestra la estructura y los programas de la Comision para la Cooperacion Ambiental (CCA). Asimismo, se describen los proyectos ambientales, los objetivos junto con sus correspondientes tratados. Mas adelante, se explican tanto los beneficios ambientales como aquellos que no lo son. Igualmente, explican las cuestiones que podrian cambiar de: suceder la expansion de la Comision Federal de Electricidad (CFE), incrementarse el auto- suministro de la energia renovable y los sistemas interconectados.

  17. North America and Asia Pacific LNG markets

    International Nuclear Information System (INIS)

    The liquefied natural gas (LNG) export opportunities in the Asia Pacific market were reviewed. Some of the differences that affect a North American LNG projects compared to more typical LNG projects were also outlined. The two main aspects of the LNG market in North America include the establishment of LNG import terminals on the east and southern coasts of the United States and the development of export oriented LNG projects. The Pac-Rim LNG project calls for initial delivery to South Korea of 4.0 MTPA by the end of 2000. A large LNG project has also been proposed for the year 2005 which would use Prudhoe Bay gas. Generally, in North America, there is little use for large scale LNG import projects because of the vast pipeline network that delivers gas reliably and at low cost anywhere in North America. However, LNG remains a good alternative for the Asia Pacific region because of the lack of a pipeline network. Also, Japan, Korea and Taiwan, the three main centers for LNG demand, have no domestic energy supplies and rely on imported energy sources. China is another major market opportunity for LNG. The Pac-Rim LNG project differs from others of its kind in that usually, an LNG project is based on the availability of large reservoirs of natural gas owned by state governments and involves production agreements with multi-national oil and gas companies. This scenario is simply not possible in Canada's deregulated environment. In contrast, the existence of upstream facilities, technical expertise, and low capital costs, hence reduced risks and time to develop an LNG project, gives Canada significant advantages. 3 tabs., 3 figs

  18. Seasonal Climate Associated with Major Shipping Routes in the North Pacific and North Atlantic

    Directory of Open Access Journals (Sweden)

    Jau-Ming Chen

    2014-01-01

    Full Text Available The major shipping routes in the North Pacific (NP and North Atlantic (NA are analyzed via ship-reported records compiled by the International Comprehensive Ocean-Atmosphere Data Set (ICOADS. The shipping route seasonal characteristics and associated climatic features are also examined. In the NP, the dominant cross-basin route takes a great-circle path between East Asia and North America along 54°N54°N north of the Aleutian Islands throughout the year. This route penetrates the Aleutian low center where ocean waves and winds are relatively weaker than those in the _ southern section south of 50°N.50°N. Moreover, the _ spherical shape makes a higher-latitude route shorter in navigational distance across the NP than a lower-latitude route. Two additional mid-latitude routes through the 40°40° - 50°N50°N region appear in summer when the Aleutian low vanishes. In the NA, the major shipping routes form an X-shaped pattern in the oceans south of 40°N40°N to connect North America/the Panama Canal and the Mediterranean Sea/the British Isles and Europe. These major shipping routes are far from the influence of the Icelandic low and thus are used throughout the year due to the stability in marine conditions and their general efficiency. A third and more zonal route appears to the north of the X-shaped routes in the 40°40° - 50°N50°N region. Weak influence from the Icelandic low on marine conditions during summer and spring means that more ships take this route in summer and spring than in winter and fall.

  19. NOrth AMerica Soil (NOAM-SOIL) Database

    Science.gov (United States)

    Miller, D. A.; Waltman, S. W.; Geng, X.; James, D.; Hernandez, L.

    2009-05-01

    NOAM-SOIL is being created by combining the CONUS-SOIL database with pedon data and soil geographic data coverages from Canada and Mexico. Completion of the in-progress NOrth AMerica Soil (NOAM-SOIL) database will provide complete North America coverage comparable to CONUS. Canadian pedons, which number more than 500, have been painstakingly transcribed to a common format, from hardcopy, and key- entered. These data, along with map unit polygons from the 1:1,000,000 Soil Landscapes of Canada, will be used to create the required spatial data coverages. The Mexico data utilizes the INEGI 1:1,000,000 scale soil map that was digitized by U. S. Geological Survey EROS Data Center in the mid 1990's plus about 20,000 pedons. The pedon data were published on the reverse side of the paper 1:250,000 scale Soil Map of Mexico and key entered by USDA and georeferenced by Penn State to develop an attribute database that can be linked to the 1:1,000,000 scale Soil Map of Mexico based on taxonomic information and geographic proximity. The essential properties that will be included in the NOAM-SOIL data base are: layer thickness (depth to bedrock or reported soil depth); available water capacity; sand, silt, clay; rock fragment volume; and bulk density. For quality assurance purposes, Canadian and Mexican soil scientists will provide peer review of the work. The NOAM-SOIL project will provide a standard reference dataset of soil properties for use at 1km resolution by NACP modelers for all of North America. All data resources, including metadata and selected raw data, will be provided through the Penn State web site: Soil Information for Environmental Modeling and Ecosystem Management (www.soilinfo.psu.edu). Progress on database completion is reported.

  20. Volcanic forcing of the North Atlantic Oscillation over the last 2,000 years

    Science.gov (United States)

    Breitenbach, Sebastian F. M.; Ridley, Harriet E.; Lechleitner, Franziska A.; Asmerom, Yemane; Rehfeld, Kira; Prufer, Keith M.; Kennett, Douglas J.; Aquino, Valorie V.; Polyak, Victor; Goswami, Bedartha; Marwan, Norbert; Haug, Gerald H.; Baldini, James U. L.

    2015-04-01

    The North Atlantic Oscillation (NAO) is a principal mode of atmospheric circulation in the North Atlantic realm (Hurrell et al. 2003) and influences rainfall distribution over Europe, North Africa and North America. Although observational data inform us on multi-annual variability of the NAO, long and detailed paleoclimate datasets are required to understand the mechanisms and full range of its variability and the spatial extent of its influence. Chronologies of available proxy-based NAO reconstructions are often interdependent and cover only the last ~1,100 years, while longer records are characterized by low sampling resolution and chronological constraints. This complicates the reconstruction of regional responses to NAO changes. We present data from a 2,000 year long sub-annual carbon isotope record from speleothem YOK-I from Yok Balum Cave, Belize, Central America. YOK-I has been extensively dated using U-series (Kennett et al. 2012). Monitoring shows that stalagmite δ13C in Yok Balum cave is governed by infiltration changes associated with tropical wet season rainfall. Higher (lower) δ13C values reflect drier (wetter) conditions related to Intertropical Convergence Zone position and trade winds intensity. Comparison with NAO reconstructions (Proctor et al. 2000, Trouet et al. 2009, Wassenburg et al. 2013) reveals that YOK-I δ13C sensitively records NAO-related rainfall dynamics over Belize. The Median Absolute Deviation (MAD) of δ13C extends NAO reconstructions to the last 2,000 years and indicates that high latitude volcanic aerosols force negative NAO phases. We infer that volcanic aerosols modify inter-hemispheric temperature contrasts at multi-annual scale, resulting in meridional relocation of the ITCZ and the Bermuda-Azores High, altering NAO and tropical rainfall patterns. Decade-long dry periods in the 11th and the late 18th century relate to major high northern latitude eruptions and exemplify the climatic response to volcanic forcing by

  1. Inventory of Atlantic White Cedar Remnant Stands in North Carolina.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This inventory was commissioned by the U.S. Air Force to identify the location and condition of extant remnant Atlantic white cedar groves and stands in North...

  2. Operational numerical prediction of rapid cyclogenesis over the North Atlantic

    OpenAIRE

    GADD, A. J.; HALL, C. D.; KRUZE, R. E.

    2011-01-01

    The current generation of operational numerical weather prediction models has shown considerable skill in handling cyclogenesis. This paper assesses the accuracy of forecasts of rapid cyclogenesis over the North Atlantic from the operational NWP system at Bracknell and attempts to isolate the factors relevant to successful prediction. Illustrative material is drawn in particular from the case of the record low pressure centre that developed over the North Atlantic on 14 December 1986.DOI: 10....

  3. On multidecadal and quasi-decadal North Atlantic variability

    OpenAIRE

    Alvarez-Garcia, F.; Latif, Mojib; Biastoch, Arne

    2008-01-01

    Observed sea surface temperatures (SSTs) in the North Atlantic from 1958 through 2000, as well as data from an ocean model simulation driven with the atmospheric variability observed during the same period, are examined using multichannel singular spectrum analysis. The two leading oscillatory modes are associated with a multidecadal and a quasi-decadal period. The former is connected to a basinwide uniform SST pattern and changes in the deep North Atlantic meridional overturning circulation....

  4. Imaging the lithosphere of rifted passive margins using waveform tomography: North Atlantic, South Atlantic and beyond

    Science.gov (United States)

    Lebedev, Sergei; Schaeffer, Andrew; Celli, Nicolas Luca

    2016-04-01

    Lateral variations in seismic velocities in the upper mantle reflect variations in the temperature of the rocks at depth. Seismic tomography thus provides a proxy for lateral changes in the temperature and thickness of the lithosphere. It can map the deep boundaries between tectonic blocks with different properties and age of the lithosphere. Our 3D tomographic models of the upper mantle and the crust at the Atlantic and global scales are constrained by an unprecedentedly large global dataset of broadband waveform fits (over one million seismograms) and provide improved resolution of the lithosphere, compared to other available models. The most prominent high-velocity anomalies, seen down to 150-200 km depths, indicate the cold, thick, stable mantle lithosphere beneath Precambrian cratons, including those in North America, Greenland, northern and eastern Europe, Africa and South America. The dominant, large-scale, low-velocity feature is the global system of mid-ocean ridges, with broader low-velocity regions near hotspots, including Iceland. Currently active continental rifts show highly variable expression in the upper mantle, from pronounced low velocities to weak anomalies; this correlates with the amount of magmatism within the rift zone. Rifted passive margins have typically undergone cooling since the rifting and show more subtle variations in their seismic-velocity structure. Their thermal structure and evolution, however, are also shaped by 3D geodynamic processes since their formation, including cooling by the adjacent cratonic blocks inland and heating by warm oceanic asthenosphere.

  5. Reorganization of the North Atlantic Oscillation during early Holocene deglaciation

    Science.gov (United States)

    Wassenburg, Jasper A.; Dietrich, Stephan; Fietzke, Jan; Fohlmeister, Jens; Jochum, Klaus Peter; Scholz, Denis; Richter, Detlev K.; Sabaoui, Abdellah; Spötl, Christoph; Lohmann, Gerrit; Andreae, Meinrat O.; Immenhauser, Adrian

    2016-08-01

    The North Atlantic Oscillation is the dominant atmospheric pressure mode in the North Atlantic region and affects winter temperature and precipitation in the Mediterranean, northwest Europe, Greenland, and Asia. The index that describes the sea-level pressure difference between Iceland and the Azores is correlated with a dipole precipitation pattern over northwest Europe and northwest Africa. How the North Atlantic Oscillation will develop as the Greenland ice sheet melts is unclear. A potential past analogue is the early Holocene, during which melting ice sheets around the North Atlantic freshened surface waters, affecting the strength of the meridional overturning circulation. Here we present a Holocene rainfall record from northwest Africa based on speleothem δ18O and compare it against a speleothem-based rainfall record from Europe. The two records are positively correlated during the early Holocene, followed by a shift to an anti-correlation, similar to the modern record, during the mid-Holocene. On the basis of our simulations with an Earth system model, we suggest the shift to the anti-correlation reflects a large-scale atmospheric and oceanic reorganization in response to the demise of the Laurentide ice sheet and a strong reduction of meltwater flux to the North Atlantic, pointing to a potential sensitivity of the North Atlantic Oscillation to the melting of ice sheets.

  6. Toxocariasis in North America: a systematic review.

    Directory of Open Access Journals (Sweden)

    Rachel M Lee

    2014-08-01

    Full Text Available Toxocariasis is an important neglected tropical disease that can manifest as visceral or ocular larva migrans, or covert toxocariasis. All three forms pose a public health problem and cause significant morbidity in areas of high prevalence. To determine the burden of toxocariasis in North America, we conducted a systematic review of the literature following PRISMA guidelines. We found 18 articles with original prevalence, incidence, or case data for toxocariasis. Prevalence estimates ranged from 0.6% in a Canadian Inuit community to 30.8% in Mexican children with asthma. Commonly cited risk factors included: African-American race, poverty, male sex, and pet ownership or environmental contamination by animal feces. Increased prevalence of Toxocara spp. infection was linked in a group of case control studies conducted in Mexico to several high risk groups including waste pickers, asthmatic children, and inpatient psychiatry patients. Further research is needed to determine the true current burden of toxocariasis in North America; however the prevalence estimates gathered in this review suggest that the burden of disease is significant.

  7. The bentonite industry in North America

    International Nuclear Information System (INIS)

    The Canadian Nuclear Fuel Waste Management Program is studying a concept for the disposal of nuclear fuel waste at a depth of 500 to 1000 m below the surface in stable crystalline rock of the Canadian Shield. The waste containers would be surrounded by a clay-based buffer material, composed of equal proportions of bentonite clay and silica sand. In the reference disposal concept, some 1.9 x 105 Mg of used fuel would be emplaced. This would require 2.5 x 106 Mg of bentonite. A review of the bentonite industry in North America was carried out to establish the availability of sufficient high-quality material. There are proven reserves of sodium bentonite clay in excess of 1.5 x 108 Mg, and vast supplies are known to exist but not yet proven. The Canadian conceptual disposal vault would require 6 x 104 Mg of sodium bentonite each year for 40 years. The bentonite industry of North America has an installed annual production capacity of 2 x 107 Mg. A disposal vault would therefore require approximately 2% of the industry capacity. A number of commercial products have been screened for potential suitability for use as a component of the buffer. Ten currently marketed bentonite products have been identified as meeting the initial quality standards for the buffer, and two non-commercial bentonites have been identified as having the potential for use in a disposal vault. (Author) (14 figs., 7 tabs., 18 refs.)

  8. The East Atlantic - West Russia Teleconnection in the North Atlantic: Climate Impact and Relation to Rossby Wave Propagation

    Science.gov (United States)

    Lim, Young-Kwon

    2014-01-01

    Large-scale winter teleconnection of the East Atlantic - West Russia (EA-WR) over the Atlantic and surrounding regions is examined in order to quantify its impacts on temperature and precipitation and identify the physical mechanisms responsible for its existence. A rotated empirical orthogonal function (REOF) analysis of the upper-tropospheric monthly height field captures successfully the EA-WR pattern and its interannual variation, with the North Atlantic Oscillation as the first mode. EA-WRs climate impact extends from eastern North America to Eurasia. The positive (negative) EA-WR produces positive (negative) temperature anomalies over the eastern US, western Europe and Russia east of Caspian Sea, with negative (positive) anomalies over eastern Canada, eastern Europe including Ural Mountains and the Middle East. These anomalies are largely explained by lower-tropospheric temperature advections. Positive (negative) precipitation anomalies are found over the mid-latitude Atlantic and central Russia around 60E, where lower-level cyclonic (anticyclonic) circulation anomaly is dominant. The eastern Canada and the western Europe are characterized by negative (positive) precipitation anomalies.The EA-WR is found to be closely associated with Rossby wave propagation. Wave activity fluxes show that it is strongly tied to large-scale stationary waves. Furthermore, a stationary wave model (SWM) forced with vorticity transients in the mid-latitude Atlantic (approximately 40N) or diabatic heat source over the subtropical Atlantic near the Caribbean Sea produces well-organized EA-WR-like wave patterns, respectively. Sensitivity tests with the SWM indicate improvement in the simulation of the EA-WR when the mean state is modified to have a positive NAO component that enhances upper-level westerlies between 40-60N.

  9. Decadal predictions of the North Atlantic CO2 uptake

    Science.gov (United States)

    Li, Hongmei; Ilyina, Tatiana; Müller, Wolfgang A.; Sienz, Frank

    2016-03-01

    As a major CO2 sink, the North Atlantic, especially its subpolar gyre region, is essential for the global carbon cycle. Decadal fluctuations of CO2 uptake in the North Atlantic subpolar gyre region are associated with the evolution of the North Atlantic Oscillation, the Atlantic meridional overturning circulation, ocean mixing and sea surface temperature anomalies. While variations in the physical state of the ocean can be predicted several years in advance by initialization of Earth system models, predictability of CO2 uptake has remained unexplored. Here we investigate the predictability of CO2 uptake variations by initialization of the MPI-ESM decadal prediction system. We find large multi-year variability in oceanic CO2 uptake and demonstrate that its potential predictive skill in the western subpolar gyre region is up to 4-7 years. The predictive skill is mainly maintained in winter and is attributed to the improved physical state of the ocean.

  10. Decadal predictions of the North Atlantic CO2 uptake.

    Science.gov (United States)

    Li, Hongmei; Ilyina, Tatiana; Müller, Wolfgang A; Sienz, Frank

    2016-01-01

    As a major CO2 sink, the North Atlantic, especially its subpolar gyre region, is essential for the global carbon cycle. Decadal fluctuations of CO2 uptake in the North Atlantic subpolar gyre region are associated with the evolution of the North Atlantic Oscillation, the Atlantic meridional overturning circulation, ocean mixing and sea surface temperature anomalies. While variations in the physical state of the ocean can be predicted several years in advance by initialization of Earth system models, predictability of CO2 uptake has remained unexplored. Here we investigate the predictability of CO2 uptake variations by initialization of the MPI-ESM decadal prediction system. We find large multi-year variability in oceanic CO2 uptake and demonstrate that its potential predictive skill in the western subpolar gyre region is up to 4-7 years. The predictive skill is mainly maintained in winter and is attributed to the improved physical state of the ocean. PMID:27026490

  11. Overview of the Summer 2004 Intercontinental Chemical Transport Experiment–North America (INTEX-A)

    OpenAIRE

    Singh, H. B.; Brune, W H; J. H. Crawford; Jacob, Daniel J.; Russel, P. B.

    2006-01-01

    The INTEX-A field mission was conducted in the summer of 2004 (1 July to 15 August 2004) over North America (NA) and the Atlantic in cooperation with multiple national and international partners as part of a consortium called ICARTT. The main goals of INTEX-A were to (1) characterize the composition of the troposphere over NA, (2) characterize the outflow of pollution from NA and determine its chemical evolution during transatlantic transport, (3) validate satellite observations of tropospher...

  12. The climate of North America during the past 2,000 years reconstructed from pollen data

    Science.gov (United States)

    Ladd, Matthew; Viau, Andre; Gajewski, Konrad

    2013-04-01

    The temperature of the warmest month was reconstructed for the past 2,000 years using almost 750 pollen sites from the North American Pollen Database. The modern analogue technique (MAT)implemented using MATTOOLS was used to quantify paleoclimates using a modern pollen database with over 4,800 calibration sites from across North America. Across North America, both the Medieval Warm Period (MWP) and Little Ice Age (LIA) were cooler than the present (1961-1990 AD, and the MWP was warmer than the LIA over at least three ecoregions in North America. Regional time series from the forest-tundra, boreal, conifer-hardwood forest show positive anomalies up to 0.6 °C during the MWP and up to -0.3 °C during the LIA. The reconstructions from the Southwestern United States, arctic, prairie and mountain vegetation ecoregions are less reliable due to fewer available data. These reconstructed anomalies during the MWP and LIA are significant deviations from the long-term neoglacial cooling. There is evidence for a poleward shift of the summer Subtropical High Pressure system in the North Atlantic during the MWP. This reconstruction provides important insight into the climate for large regions of North America during the MWP which is precisely where data and reconstructions are needed to better understand the geographical extent of the climate anomalies of this time period. These pollen-based reconstructions are comparable to those based on tree-rings.

  13. North Atlantic Deep Water Production during the Last Glacial Maximum

    Science.gov (United States)

    Howe, Jacob N. W.; Piotrowski, Alexander M.; Noble, Taryn L.; Mulitza, Stefan; Chiessi, Cristiano M.; Bayon, Germain

    2016-06-01

    Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO2. The water mass structure of the glacial deep Atlantic Ocean and the mechanism by which it may have sequestered carbon remain elusive. Here we present neodymium isotope measurements from cores throughout the Atlantic that reveal glacial-interglacial changes in water mass distributions. These results demonstrate the sustained production of North Atlantic Deep Water under glacial conditions, indicating that southern-sourced waters were not as spatially extensive during the Last Glacial Maximum as previously believed. We demonstrate that the depleted glacial δ13C values in the deep Atlantic Ocean cannot be explained solely by water mass source changes. A greater amount of respired carbon, therefore, must have been stored in the abyssal Atlantic during the Last Glacial Maximum. We infer that this was achieved by a sluggish deep overturning cell, comprised of well-mixed northern- and southern-sourced waters.

  14. 78 FR 60270 - BP America Inc., BP Corporation North America Inc., BP America Production Company, and BP Energy...

    Science.gov (United States)

    2013-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission BP America Inc., BP Corporation North America Inc., BP America Production Company, and BP Energy Company; Notice of Designation of Commission Staff as Non-Decisional With...

  15. Incursions of southern-sourced water into the deep North Atlantic during late Pliocene glacial intensification

    Science.gov (United States)

    Lang, David C.; Bailey, Ian; Wilson, Paul A.; Chalk, Thomas B.; Foster, Gavin L.; Gutjahr, Marcus

    2016-05-01

    The circulation and internal structure of the oceans exert a strong influence on Earth's climate because they control latitudinal heat transport and the segregation of carbon between the atmosphere and the abyss. Circulation change, particularly in the Atlantic Ocean, is widely suggested to have been instrumental in the intensification of Northern Hemisphere glaciation when large ice sheets first developed on North America and Eurasia during the late Pliocene, approximately 2.7 million years ago. Yet the mechanistic link and cause/effect relationship between ocean circulation and glaciation are debated. Here we present new records of North Atlantic Ocean structure using the carbon and neodymium isotopic composition of marine sediments recording deep water for both the Last Glacial to Holocene (35-5 thousand years ago) and the late Pliocene to earliest Pleistocene (3.3-2.4 million years ago). Our data show no secular change. Instead we document major southern-sourced water incursions into the deep North Atlantic during prominent glacials from 2.7 million years ago. Our results suggest that Atlantic circulation acts as a positive feedback rather than as an underlying cause of late Pliocene Northern Hemisphere glaciation. We propose that, once surface Southern Ocean stratification and/or extensive sea-ice cover was established, cold-stage expansions of southern-sourced water such as those documented here enhanced carbon dioxide storage in the deep ocean, helping to increase the amplitude of glacial cycles.

  16. Chromosomal differences between European and North American Atlantic salmon discovered by linkage mapping and supported by fluorescence in situ hybridization analysis

    Directory of Open Access Journals (Sweden)

    Brenna-Hansen Silje

    2012-08-01

    Full Text Available Abstract Background Geographical isolation has generated a distinct difference between Atlantic salmon of European and North American Atlantic origin. The European Atlantic salmon generally has 29 pairs of chromosomes and 74 chromosome arms whereas it has been reported that the North American Atlantic salmon has 27 chromosome pairs and an NF of 72. In order to predict the major chromosomal rearrangements causing these differences, we constructed a dense linkage map for Atlantic salmon of North American origin and compared it with the well-developed map for European Atlantic salmon. Results The presented male and female genetic maps for the North American subspecies of Atlantic salmon, contains 3,662 SNPs located on 27 linkage groups. The total lengths of the female and male linkage maps were 2,153 cM and 968 cM respectively, with males characteristically showing recombination only at the telomeres. We compared these maps with recently published SNP maps from European Atlantic salmon, and predicted three chromosomal reorganization events that we then tested using fluorescence in situ hybridization (FISH analysis. The proposed rearrangements, which define the differences in the karyotypes of the North American Atlantic salmon relative to the European Atlantic salmon, include the translocation of the p arm of ssa01 to ssa23 and polymorphic fusions: ssa26 with ssa28, and ssa08 with ssa29. Conclusions This study identified major chromosomal differences between European and North American Atlantic salmon. However, while gross structural differences were significant, the order of genetic markers at the fine-resolution scale was remarkably conserved. This is a good indication that information from the International Cooperation to Sequence the Atlantic salmon Genome, which is sequencing a European Atlantic salmon, can be transferred to Atlantic salmon from North America.

  17. Seafloor spreading pattern of the North Atlantic between 10o and 40o N : a reconstruction based on shipborne measurements and satellite altimeter data

    NARCIS (Netherlands)

    Roest, W.R.

    1987-01-01

    The history of the relative motion between North America and Africa is recorded in the floor of the central North Atlantic Ocean. The resulting pattern of magnetic anomalies and fracture zones in the area between 10° and 40° N was analysed using shipborne measurements and Seasat altimeter data. This

  18. Seafloor spreading pattern of the North Atlantic between 10⁰ and 40⁰ N : a reconstruction based on shipborne measurements and satellite altimeter data

    NARCIS (Netherlands)

    Roest, W.R.

    1987-01-01

    The history of the relative motion between North America and Africa is recorded in the floor of the central North Atlantic Ocean. The resulting pattern of magnetic anomalies and fracture zones in the area between 10° and 40° N was analysed using shipborne measurements and Seasat altimeter data. This

  19. Large Scale Drivers for the Extreme Storm Season over the North Atlantic and the UK in Winter 2013-14

    Science.gov (United States)

    Wild, Simon; Befort, Daniel J.; Leckebusch, Gregor C.

    2016-04-01

    The British Isles experienced exceptional stormy and rainy weather conditions in winter 2013-2014 while large parts of central North America recorded near record minimum surface temperatures values. Potential drivers for these cold conditions include increasingly warm surface waters of the tropical west Pacific. It has been suggested these increasing sea surface temperatures could also be the cause for extreme weather over the Europe, particularly the UK. Testing this hypothesis, we investigate mechanisms linking the tropical west Pacific and European wind storm activity. We will firstly analyse anomaly patterns along such a potential link in winter 2013-14. Secondly, we will investigate whether these identified anomaly patterns show a strong interannual relationship in the recent past. Our results, using primarily ERA-Interim Reanalysis from 1979 to 2014, show an absolute maximum of wind storm frequency over the northeast Atlantic and the British Isles in winter 2013-14. We also find absolute minimum surface temperatures in central North America and increased convective activity over the tropical west Pacific in the same season. The winter 2013-14 was additionally characterized by anomalous warm sea surface temperatures over the subtropical northwest Atlantic. Although the interannual variability of wind storms in the northeast Atlantic and surface temperatures in North America are significantly anti-correlated, we cannot directly relate wind storm frequency with tropical west Pacific anomalies. We thus conclude that the conditions over the Pacific in winter 2013-14 were favourable but not sufficient to explain the record number of wind storms in this season. Instead, we suggest that warm north Atlantic sea surface temperature anomalies in combination with cold surface temperatures over North America played a more important role for generating higher wind storm counts over the northeast Atlantic and the UK.

  20. Socially Engaged Buddhist Nuns: Activism in Taiwan and North America

    Directory of Open Access Journals (Sweden)

    Karma Lekshe Tsomo

    2015-02-01

    Full Text Available The last decades of the twentieth century have been a time of new visibility and social activism for Buddhists in Taiwan and around the world. This paper compares the social engagement of nuns in the Chinese Buddhist tradition in Taiwan and North America. I would like to argue that whereas nuns in Taiwan have developed a variety of approaches to social involvement, their counterparts in the Chinese diaspora in North America have had to face a set of challenges specific to overseas Chinese communities in addition to Chinese Buddhist tradition. The article concludes with reflections on the prospects for nuns' social activism in Taiwan and North America in future years.

  1. Lead isotopes in the western North Atlantic: Transient tracers of pollutant lead inputs

    International Nuclear Information System (INIS)

    In the early 1980s, Patterson and colleagues demonstrated that most lead in oceanic surface waters had an anthropogenic origin. Their discovery occurred during the phasing out of leaded gasoline in North America initiated in the previous decade. The corresponding decrease in anthropogenic lead emissions, verified by Pb/210Pb ratios, accounted for the systematic decline in lead concentrations in surface waters of the western Sargasso Sea. Subsequent changes in anthropogenic lead inputs to the western Sargasso Sea surface waters have been documented by measurements of lead concentrations, isotopic compositions (206Pb/207Pb, 208Pb/206Pb), and Pb/210Pb ratios in precipitation and seawater for the period of 1981 to 1994. These data indicate the easterly trade winds are now the primary source of atmospheric lead in Bermuda, and they confirm that the decline of lead concentrations in the North Atlantic is associated with the phasing out of leaded gasoline in North America and western Europe over the past decade. Moreover, temporal variations in the relative contribution of industrial lead inputs from the two sides of the North Atlantic over that period can be quantified based on differences in their isotopic composition. The transient character of those isotopic signatures also allows calculations of pollutant lead penetration rates into the mixed layer and upper thermocline of the western Sargasso Sea

  2. Deglacial hydroclimate of midcontinental North America

    Science.gov (United States)

    Voelker, Steven L.; Stambaugh, Michael C.; Guyette, Richard P.; Feng, Xiahong; Grimley, David A.; Leavitt, Steven W.; Panyushkina, Irina; Grimm, Eric C.; Marsicek, Jeremiah P.; Shuman, Bryan; Brandon Curry, B.

    2015-03-01

    During the last deglaciation temperatures over midcontinental North America warmed dramatically through the Bølling-Allerød, underwent a cool period associated with the Younger-Dryas and then reverted to warmer, near modern temperatures during the early Holocene. However, paleo proxy records of the hydroclimate of this period have presented divergent evidence. We reconstruct summer relative humidity (RH) across the last deglacial period using a mechanistic model of cellulose and leaf water δ18O and δD combined with a pollen-based temperature proxy to interpret stable isotopes of sub-fossil wood. Midcontinental RH was similar to modern conditions during the Last Glacial Maximum, progressively increased during the Bølling-Allerød, peaked during the Younger-Dryas, and declined sharply during the early Holocene. This RH record suggests deglacial summers were cooler and characterized by greater advection of moisture-laden air-masses from the Gulf of Mexico and subsequent entrainment over the mid-continent by a high-pressure system over the Laurentide ice sheet. These patterns help explain the formation of dark-colored cumulic horizons in many Great Plains paleosol sequences and the development of no-analog vegetation types common to the Midwest during the last deglacial period. Likewise, reduced early Holocene RH and precipitation correspond with a diminished glacial high-pressure system during the latter stages of ice-sheet collapse.

  3. Variability of the North Atlantic Current over the Common Era

    Science.gov (United States)

    Moffa Sanchez, P.; Hall, I. R.; Born, A.; Thornalley, D. J.; Barker, S.; Richter, T.

    2014-12-01

    Over the last 2000 years, the climate of the North Atlantic region was punctuated by centennial oscillations, which despite their small magnitude had important societal impacts, particularly in NW Europe. The most favoured explanations for this climate variability invoke changes in external forcings (such as solar activity and explosive volcanism) amplified by ocean and atmosphere feedbacks, mainly involving the Atlantic Meridional Overturning Circulation (AMOC) and the North Atlantic Oscillation. However, the scarcity of highly resolved archives has hampered our understanding of the involvement of the ocean-atmosphere interactions in these climatic oscillations. We present a subdecadally resolved temperature and salinity record derived from paired Mg/Ca-δ18O measurements on planktonic foraminifera from a marine sediment core located in the pathway of the North Atlantic Current. Our findings show a strong centennial co-variability of the temperature and salinity of the surface limb of the AMOC with solar irradiance (Moffa-Sánchez et al. 2014- NGS). Climate model results from this study show a similar correlation over the last millennium and we infer that the hydrographic changes were linked to the strength of the subpolar gyre associated with changes in atmospheric circulation. Specifically, in the simulation, low solar irradiance promotes the development of frequent and persistent atmospheric blocking events, in which a quasi-stationary high-pressure system in the eastern North Atlantic, also known as blocking event, modifies the flow of the westerly winds. To further explore the response of the upper limb of the AMOC to solar forcing found in Moffa-Sánchez et al. 14, we synthesize new and available proxy-data from the North Atlantic Current in combination with analysis from CMIP5 simulations of the last millennium.

  4. Effects of the North Atlantic Oscillation on sea ice breeding habitats of harp seals ( Pagophilus groenlandicus) across the North Atlantic

    Science.gov (United States)

    Friedlaender, Ari S.; Johnston, David W.; Halpin, Patrick N.

    2010-07-01

    Harp seals ( Pagophilus groenlandicus) are an abundant and commercially exploited species of phocid seal in the North Atlantic. Harp seals are entirely dependent on annual sea ice for breeding purposes and the distribution, abundance, and constitution of sea ice in this region are subject to tremendous interannual variability. As such, harp seal population dynamics are likely intimately tied to climate variability and global change. We used satellite-derived images of sea ice cover to determine trends in available habitat at the four major harp seal breeding areas in the North Atlantic, and assessed linkages amongst sea ice conditions and variability in the North Atlantic Oscillation (NAO) during 1978-2006. The White Sea breeding area had the highest annual ice concentrations, while the Gulf of St. Lawrence and Front regions were the most variable over time. We confirmed a consistent positive correlation between the NAO index and the amount of sea ice cover in Western North Atlantic breeding areas off Canada. Furthermore, we found an opposite and consistent negative correlation between the NAO and sea ice cover in the eastern-most breeding areas, leading to an out-of-phase signal between the Western and Eastern (particularly the White Sea) North Atlantic. These results indicate that sea ice dynamics in the breeding regions of harp seals are controlled, to some extent, by the phase of the NAO and its effects on weather across the North Atlantic. Previous studies indicate that poor ice conditions can have negative effects on harp seal survival and the consistent relationships between breeding habitat and NAO conditions that are described here have implications for both the biology and management of harp seal populations.

  5. Surface electric fields for North America during historical geomagnetic storms

    Science.gov (United States)

    Wei, Lisa H.; Homeier, Nichole; Gannon, Jennifer L.

    2013-01-01

    To better understand the impact of geomagnetic disturbances on the electric grid, we recreate surface electric fields from two historical geomagnetic storms—the 1989 “Quebec” storm and the 2003 “Halloween” storms. Using the Spherical Elementary Current Systems method, we interpolate sparsely distributed magnetometer data across North America. We find good agreement between the measured and interpolated data, with larger RMS deviations at higher latitudes corresponding to larger magnetic field variations. The interpolated magnetic field data are combined with surface impedances for 25 unique physiographic regions from the United States Geological Survey and literature to estimate the horizontal, orthogonal surface electric fields in 1 min time steps. The induced horizontal electric field strongly depends on the local surface impedance, resulting in surprisingly strong electric field amplitudes along the Atlantic and Gulf Coast. The relative peak electric field amplitude of each physiographic region, normalized to the value in the Interior Plains region, varies by a factor of 2 for different input magnetic field time series. The order of peak electric field amplitudes (largest to smallest), however, does not depend much on the input. These results suggest that regions at lower magnetic latitudes with high ground resistivities are also at risk from the effect of geomagnetically induced currents. The historical electric field time series are useful for estimating the flow of the induced currents through long transmission lines to study power flow and grid stability during geomagnetic disturbances.

  6. Ice Age Geomorphology of North America

    Science.gov (United States)

    Wickert, A. D.; Anderson, R. S.; Mitrovica, J. X.; Picard, K.

    2012-12-01

    The Last Glacial Cycle in North America dramatically modified drainage patterns and geomorphology on a continental scale. As a consequence, the evolution of river systems holds information on the patterns of glaciation and isostatic response. This information can, in principle, be used to reconstruct the volumes of ice sheet sectors and eroded material by connecting the upstream ice sheets with stable isotope and other sedimentary records in offshore basins. Here we integrate this coupled geomorphic-hydrologic-glacial-sedimentary-paleoceanographic system to solve both the forward problem, how rivers evolve in response to Ice Age forcing, as well as the inverse problem, how fluvial systems record Quaternary history. The connections that define this system provide a link between climate and geomorphology that extends beyond the traditionally considered watershed-to-landscape scale by incorporating solid Earth deformations, large-scale shoreline migration, and the high amplitude changes in climate that drive the growth and decay of major ice sheets and water delivery to the bounding river systems. We address this continental scale problem using a valley-resolving drainage reconstruction that incorporates a realistic ice sheet history, a gravitationally self-consistent treatment of ice-age sea-level changes that includes shoreline migration, and precipitation and evapotranspiration retrodicted using general circulation model (GCM) runs. Drainage divides over the flat-lying North American interior migrate hundreds to thousands of kilometers in response to dynamic interactions between ice sheets and solid Earth response, and these changes coupled with post last glacial maximum (LGM) ice sheet melting drive high-amplitude variability in water and sediment discharge to the oceans. The Mackenzie River Delta records a sedimentary record produced by a highly non-eustatic sea level history and massive glacial sediment inputs routed along the axis that divided the Cordilleran

  7. Phylogeographic surveys and apomictic genetic connectivity in the North Atlantic red seaweed Mastocarpus stellatus.

    Science.gov (United States)

    Li, Jing-Jing; Hu, Zi-Min; Liu, Ruo-Yu; Zhang, Jie; Liu, Shao-Lun; Duan, De-Lin

    2016-01-01

    The North Atlantic red alga Mastocarpus stellatus is characterized by two life histories (sexual-type and direct-type), which correspond to two geographically isolated breeding groups. These features enable M. stellatus to be an interesting model to investigate how environmental shift and apomictic propagation have influenced its population genetic structure, historical demography and distribution dynamic. To test these ideas, we obtained 456 specimens from 15 locations on both sides of the North Atlantic and sequenced portion of the nuclear internal transcribed spacer (ITS), mitochondrial cox2-3 region (COX) and plastid RuBisCo spacer (RLS). Median-joining networks and ML trees inferred from COX and RLS consistently revealed two gene lineages (mtDNA: CN, CS; cpDNA: RN, RS). The concatenated COX and RLS markers yielded three cytotypes: a northern CN-RN, a southern CS-RS and a mixed cytotype CS-RN, which enabled us to roughly separate samples into D (direct-type life-cycle) and S (sexual-type life-cycle) groups (northern CN-RN and mixed cytotype CS-RN=D; southern CS-RS=S). Pairwise FST analysis of the D group revealed a high level of genetic differentiation both along European coasts and across the Atlantic basin. Bayesian skyline plots (BSPs) and IMa analyses indicated that M. stellatus underwent slight demographic expansion at the late-Pleistocene, with the beginning of divergence between lineages dating to c. 0.189Ma (95%HPD: 0.083-0.385Ma). IMa analyses also revealed asymmetric genetic exchange among European populations and a predominant postglacial trans-Atlantic migration from Norway and Galway Bay to North America. Our study highlights the importance of phylogeographic approaches to discover the imprints of climate change, life histories and gene flow in driving population genetic connectivity and biogeographic distribution of intertidal seaweeds in the North Atlantic. PMID:26528630

  8. The North Atlantic Oscillation and oceanic precipitation variability

    Energy Technology Data Exchange (ETDEWEB)

    Mariotti, Annarita [University of Maryland, Earth System Science Interdisciplinary Center (ESSIC), College Park, MD (United States); ENEA, Rome (Italy); Arkin, Phillip [University of Maryland, Earth System Science Interdisciplinary Center (ESSIC), College Park, MD (United States)

    2007-01-15

    Global North Atlantic Oscillation (NAO) oceanic precipitation features in the latter half of the twentieth century are documented based on the intercomparison of multiple state-of-the-art precipitation datasets and the analysis of the NAO atmospheric circulation and SST anomalies. Most prominent precipitation anomalies occur over the ocean in the North Atlantic, where in winter a ''quadrupole-like'' pattern is found with centers in the western tropical Atlantic, sub-tropical Atlantic, high-latitude eastern Atlantic and over the Labrador Sea. The extent of the sub-tropical and high-latitude center and the amount of explained variance (over 50%) are quite remarkable. However, the tropical Atlantic center is probably the most intriguing feature of this pattern apparently linking the NAO with ITCZ variability. In summer, the pattern is ''tripole-like'' with centers in the eastern Mediterranean Sea, the North Sea/Baltic Sea and in the sub-polar Atlantic. In the eastern Indian Ocean, the correlation is positive in winter and negative in summer, with some link to ENSO variability. The sensitivity of these patterns to the choice of the NAO index is minor in winter while quite important in summer. Interannual NAO precipitation anomalies have driven similar fresh water variations in these ''key'' regions. In the sub-tropical and high-latitude Atlantic in winter precipitation anomalies have been roughly 15 and 10% of climatology per unit change of the NAO, respectively. Decadal changes of the NAO during the last 50 years have also influenced precipitation and fresh water flux at these time-scales, with values lower (higher) than usual in the high-latitude eastern North Atlantic (Labrador Sea) in the 1960s and the late 1970s, and an opposite situation since the early 1980s; in summer the North Sea/Baltic region has been drier than usual during the period 1965-1975 when the NAO was generally positive. (orig.)

  9. Bathymetric Shaded Relief of North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Bathymetric Shaded Relief of North America map layer shows depth ranges using colors, with relief enhanced by shading. The image was derived from the National...

  10. Imperiled Freshwater and Diadromous Fishes of North America

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — List of imperiled freshwater and diadromous fishes of North America as determined by the 2008 American Fisheries Society (AFS) Endangered Species Committee (ESC) on...

  11. Topographic and Bathymetric Shaded Relief of North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Topographic and Bathymetric Shaded Relief of North America map layer shows depth and elevation ranges using colors, with relief enhanced by shading. The image...

  12. Classification of Forest Fragmentation in North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of North America including the Caribbean and most of Mexico. The map layer is an excerpt from a global assessment of forest...

  13. Grayscale North America Shaded Relief ? 1-Kilometer Resolution - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The grayscale North America shaded relief data were derived from the GTOPO30 elevation data. GTOPO30 is a global digital elevation model (DEM) with a horizontal...

  14. Browning boreal forests of western North America

    Science.gov (United States)

    Verbyla, David

    2011-12-01

    The GIMMS NDVI dataset has been widely used to document a 'browning trend' in North American boreal forests (Goetz et al 2005, Bunn et al 2007, Beck and Goetz 2011). However, there has been speculation (Alcaraz-Segura et al 2010) that this trend may be an artifact due to processing algorithms rather than an actual decline in vegetation activity. This conclusion was based primarily on the fact that GIMMS NDVI did not capture NDVI recovery within most burned areas in boreal Canada, while another dataset consistently showed post-fire increasing NDVI. I believe that the results of Alcaraz-Segura et al (2010) were due simply to different pixel sizes of the two datasets (64 km2 versus 1 km2 pixels). Similar results have been obtained from tundra areas greening in Alaska, with the results simply due to these pixel size differences (Stow et al 2007). Furthermore, recent studies have documented boreal browning trends based on NDVI from other sensors. Beck and Goetz (2011) have shown the boreal browning trend derived from a different sensor (MODIS) to be very similar to the boreal browning trend derived from the GIMMS NDVI dataset for the circumpolar boreal region. Parent and Verbyla (2010) found similar declining NDVI patterns based on NDVI from Landsat sensors and GIMMS NDVI in boreal Alaska. Zhang et al (2008) found a similar 'browning trend' in boreal North America based on a production efficiency model using an integrated AVHRR and MODIS dataset. The declining NDVI trend in areas of boreal North America is consistent with tree-ring studies (D'Arrigo et al 2004, McGuire et al 2010, Beck et al 2011). The decline in tree growth may be due to temperature-induced drought stress (Barber et al 2000) caused by higher evaporative demands in a warming climate (Lloyd and Fastie 2002). In a circumpolar boreal study, Lloyd and Bunn (2007) found that a negative relationship between temperature and tree-ring growth occurred more frequently in warmer parts of species' ranges

  15. CHARACTERIZATION OF WESTERN NORTH ATLANTIC RIGHT WHALE SPRING FEEDING HABITAT

    Science.gov (United States)

    The Great South Channel region of the southwestern Gulf of Maine, between George's Bank and Cape Cod, is the primary spring feeding ground for the western North Atlantic population of the I northern right whale, E. glacialis .Since this whale is so endangered, it is critical to i...

  16. Forestry serving urban societies in the north atlantic region

    DEFF Research Database (Denmark)

    2010-01-01

    In the North Atlantic Region, the social services provided by forests play a major role. With the high level of urbanisation in many of these countries, forests and other green areas are of great importance as recreational settings for urban dwellers. In order to ensure that forests cater for the...

  17. Northeast China summer temperature and North Atlantic SST

    Science.gov (United States)

    Wu, Renguang; Yang, Song; Liu, Shi; Sun, Li; Lian, Yi; Gao, Zongting

    2011-08-01

    A previous study revealed a close relationship between interannual variations of northeast China (NEC) summer temperature and a tripole sea surface temperature (SST) anomaly pattern in the North Atlantic in preceding spring. The present study investigates the change in the above relationship and the plausible causes for the change. A tripole SST index is defined with its positive value corresponding to positive SST anomalies in the tropics and midlatitudes and negative SST anomalies in the subtropics. The tripole SST anomaly pattern has a weak correlation with NEC summer temperature during the 1950s through the mid-1970s, in sharp contrast to the 1980s and 1990s. This change is related to the difference in the persistence of the tripole SST pattern. Before the late 1970s, the tripole SST pattern weakened from spring to summer, and thus, the spring North Atlantic tripole SST pattern had a weak connection with NEC summer temperature. On the contrary, after the late 1970s, the tripole SST pattern displayed a tendency of persistence from spring to summer, contributing to circulation changes that affected NEC summer temperature. There are two factors for the persistence of the tripole SST pattern from spring to summer. One is the North Atlantic air-sea interaction, and the other is the persistence of SST anomalies in the eastern equatorial Pacific during the decay of El Niño-Southern Oscillation (ENSO). It is shown that the North Atlantic SST anomalies can have an impact on NEC summer temperature independent of ENSO.

  18. Undergraduate landscape architecture program ranked No. 1 in North America

    OpenAIRE

    Chadwick, Heather Riley

    2009-01-01

    Virginia Tech's undergraduate landscape architecture program, in the School of Architecture + Design, College of Architecture and Urban Studies, has been ranked No. 1 in North America in the 11th annual America's Best Architecture and Design Schools study by DesignIntelligence on behalf of the Design Futures Council.

  19. Sulphur in the western North Atlantic Ocean atmosphere: results from a summer 1988 ship/aircraft experiment

    Science.gov (United States)

    Galloway, James N.; Keene, William C.; Pszenny, Alexander A. P.; Whelpdale, Douglas M.; Sievering, Herman; Merrill, John T.; Boatman, Joe F.

    1990-12-01

    To investigate the relative importance of anthropogenic versus marine sources of sulfur in the North Atlantic Ocean troposphere, sulfur species were measured from aircraft, ship, and island based platforms as part of the Global Change Expedition/Coordinated Air-Sea Experiment/Western Atlantic Ocean Experiment conducted during the summer of 1988. Four synoptic meteorological cases were examined: flow from highly populated North America, lightly populated North America, tropical oceanic regions, and polar oceanic regions. Literature values suggest that 2-10 μmol m-2 day-1 of (CH3)2S are emitted from the ocean to the atmosphere in marine regions associated with the first three synoptic cases. Data from this experiment indicate that 36, 16, and 14 μmol m-2 day-1, for the highly populated North America, lightly populated North America, and tropical oceanic regions synoptic cases, respectively, were deposited to the ocean's surface. Differences between previously estimated natural emissions and calculated deposition suggest that anthropogenic sources of sulfur contribute significantly to sulfur deposition for these cases. The sulfur deposition rate for the polar oceanic regions synoptic case was 20 μmol m-2 day-1 . Given the larger range of literature values for the corresponding (CH3)2S emission rate (1-14 μmol m-2 day-1 ) , however, the relative importance of the nonmarine S source is less certain in this case.

  20. Solar Influence on the North Atlantic Oscillation - Initial Results

    CERN Document Server

    Dacie, Sally

    2015-01-01

    Some initial investigations into various atmospheric phenomena and the influence of the solar cycle on weather have been made. Strongly negative North Atlantic Oscillation (NAO) indices, which cause cold and dry winter weather in North West Europe, rarely occur during periods of high solar activity. Coupling between the troposphere and stratosphere is discussed, particularly in the context of Polar-night jet oscillation events (defined by Hitchcock et al., 2013) and the Quasi-Biennial Oscillation. The energy of North Atlantic hurricanes (as indicated by the Accumulated Cyclone Energy Index, ACE) is also linked to solar activity, via UV heating at the tropopause (Elsner et al., 2010), and is suggested as a possible mechanism through which solar activity could influence the NAO. Finally the lack of solar influence on the NAO before $\\sim$ 1950 is addressed, with a possible cause being the smaller solar cycle amplitudes. This short report contains several ideas, which may be worth pursuing further.

  1. Surface Wind Observational Database in North Eastern North America: Quality Control Procedure and Climatological Variability

    Science.gov (United States)

    Lucio-Eceiza, Etor E.; Fidel González-Rouco, J.; Navarro, Jorge; Hidalgo, Ángela; Conte, Jorge; Beltrami, Hugo

    2015-04-01

    This work summarizes the design and application of a Quality Control (QC) procedure for an observational surface wind database located in North Eastern North America. It also presents some insights of the long-term climatological variability over the region. The database consists of 527 sites (487 land stations and 40 buoys) with varying resolutions of hourly, 3 hourly and 6 hourly data, compiled from three different source institutions. The records span from 1940 to 2010 and cover an approximate spatial extension of 2.2 × 106 km2. The QC process is composed of different phases focused either on problems related with the providing source institutions or measurement errors. Due to the size of the data set, a great effort has been made on the automation of the procedures. A number of problems are associated with data management and data conventions: unification of measurement units and recording times due to the variety of institutional sources; detection of erroneous data sequence duplications within a station or among different ones; and detection of errors related with physically unrealistic data measurements. From the other hand there is a variety of treated instrumental errors: problems related with low variability, placing particular emphasis on the detection of unrealistic low wind speed records with the help of regional references; high variability related erroneous records; wind speed biases on week to monthly timescales and homogenization of wind direction records. As a result, around 1.7% of wind speed records and 0.4% of wind direction records have been deleted, making a combined total of 1.9% of removed records. Around 2.4% of wind direction data have been also corrected. The already quality controlled database allows for subsequent climatological analyses. The intra and inter decadal variability of the monthly surface wind field in such a vast and orographically complex region as the North Eastern North America is explored. Several decades of quality

  2. Adult Education Faculty and Programs in North America

    Science.gov (United States)

    Tisdell, Elizabeth J.; Wright, Robin Redmon; Taylor, Edward W.

    2016-01-01

    This article reports on the findings of a quantitative survey of North American adult education faculty and a textual analysis of websites of adult education graduate programs in North America conducted in the fall of 2013. This study examined background information about adult education faculty and programs; the nature of faculty work interests,…

  3. Constraints from observations and modeling on atmosphere–surface exchange of mercury in eastern North America

    Directory of Open Access Journals (Sweden)

    Shaojie Song

    2016-04-01

    Full Text Available Abstract Atmosphere–surface exchange of mercury, although a critical component of its global cycle, is currently poorly constrained. Here we use the GEOS-Chem chemical transport model to interpret atmospheric Hg0 (gaseous elemental mercury data collected during the 2013 summer Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks (NOMADSS aircraft campaign as well as ground- and ship-based observations in terms of their constraints on the atmosphere–surface exchange of Hg0 over eastern North America. Model–observation comparison suggests that the Northwest Atlantic may be a net source of Hg0, with high evasion fluxes in summer (our best sensitivity simulation shows an average oceanic Hg0 flux of 3.3 ng m-2 h-1 over the Northwest Atlantic, while the terrestrial ecosystem in the summer of the eastern United States is likely a net sink of Hg0 (our best sensitivity simulation shows an average terrestrial Hg0 flux of -0.6 ng m-2 h-1 over the eastern United States. The inferred high Hg0 fluxes from the Northwest Atlantic may result from high wet deposition fluxes of oxidized Hg, which are in turn related to high precipitation rates in this region. We also find that increasing simulated terrestrial fluxes of Hg0 in spring compared to other seasons can better reproduce observed seasonal variability of Hg0 concentration at ground-based sites in eastern North America.

  4. Impact of the Interdecadal Pacific Oscillation on Tropical Cyclone Activity in the North Atlantic and Eastern North Pacific

    Science.gov (United States)

    Li, Wenhong; Li, Laifang; Deng, Yi

    2015-07-01

    Tropical cyclones (TCs) are among the most devastating weather systems affecting the United States and Central America (USCA). Here we show that the Interdecadal Pacific Oscillation (IPO) strongly modulates TC activity over the North Atlantic (NA) and eastern North Pacific (eNP). During positive IPO phases, less (more) TCs were observed over NA (eNP), likely due to the presence of stronger (weaker) vertical wind shear and the resulting changes in genesis potential. Furthermore, TCs over NA tend to keep their tracks more eastward and recurve at lower latitudes during positive IPO phases. Such variations are largely determined by changes in steering flow instead of changes in genesis locations. Over the eNP, smaller track variations are observed at different IPO phases with stable, westward movements of TCs prevailing. These findings have substantial implications for understanding decadal to inter-decadal fluctuations in the risk of TC landfalls along USCA coasts.

  5. Summer North Atlantic Oscillation and flood variability in Switzerland

    Science.gov (United States)

    Peña, Juan Carlos; Schulte, Lothar; Badoux, Alexandre

    2016-04-01

    The study analyses the possible links between flood frequency in Switzerland and the North Atlantic dynamics over the last two centuries. Given the intricate topography of Switzerland, it will generate a territorial division to retain main physiographic and environmental dissimilarities between different regions. The flood variability in Switzerland over the period 1800-2010 has been determined from a flood damage index for July and August months. The index considers very severe and catastrophic floods from existing flood inventories, summarizing both the severity of these events, their spatial extent and the regional differences. Special attention will be focused on the disparities between flood dynamics at northern and southern slopes of the Alps. The analysis of the possible links between floods and North Atlantic dynamics is focused on the low-frequency atmospheric circulation patterns. Summer climate in the North Atlantic-European sector shows a principal pattern of year-to-year variability, although this pattern is weaker than the North Atlantic Oscillation (NAO) in winter and is confined to northern latitudes. By analogy the climatology community refers to this pattern as the Summer North Atlantic Oscillation (SNAO), which is defined as the main empirical orthogonal function of the standardized anomalies of the European mean sea level pressure during July and August. The flood damage index provides evidences of floods clusters in: 1830-1851, 1881-1927, 1977-1990 and 2005 to present. These clusters coincide with those reported from Switzerland and from some areas of the European continent such as the Czech Republic, Italy and the eastern half of the Iberian Peninsula. This link is not so close when compared with the flood occurrences in Germany. The analysis of the principal mode of low-frequency atmospheric variability shows that the Swiss river catchments situated on the center and southern flank of the Alps are affected by atmospherically unstable areas

  6. Toxaphene in minke whales (Balaenoptera acutorostrata) from the North Atlantic

    International Nuclear Information System (INIS)

    Toxaphene contamination of minke whales (Balaenoptera acutorostrata) from North Atlantic waters was examined for the first time. Total toxaphene and ΣCHB (sum of 11 chlorobornanes) concentrations in blubber samples ranged from 170 ± 110 and 41 ± 39 ng/g lipid weight (l.w.) for female minke whales from southeastern Greenland to 5800 ± 4100 and 1100 ± 780 ng/g l.w. for males from the North Sea, respectively. Very large variations in toxaphene concentrations among sampling areas were observed suggesting a spatial segregation of minke whales. However, much of the apparent geographical discrimination was explained by the seasonal fluctuation of animal fat mass. Patterns of CHBs in males revealed that recalcitrant CHBs were in higher proportions in animals from the more easterly areas than in animals from the more westerly areas. This trend may be influenced by the predominance of the US, over the European, input of toxaphene to North Atlantic waters. - High levels of toxaphene were found in different sub-populations of minke whales from North Atlantic waters

  7. A Comparative Analysis of Primary and Extreme Characteristics of Dry or Wet Status between Asia and North America

    Institute of Scientific and Technical Information of China (English)

    HUA Lijuan; MA Zhuguo; ZHONG Linhao

    2011-01-01

    In this study, the Palmer Drought Severity Index (PDSI) was used to analyze the average and extreme dry/wet states of Asia and North America from 1953 to 2003. The results indicate that the two continents underwent drying trends during this period. Compared with North America, Asia showed more severe drought trends. However, more significant and regular seasonal variation for drought was found in North America. The driest regions in Asia were located in the northern region of China, Mongolia, and eastern mid-Siberian plateau. Most regions in central North America were relatively wetter than other regions.The northern and southwestern regions of North America, as well as the Atlantic and Pacific coastal areas,experienced the most drought during this period. A sharp increase of the drought area and the number of extreme drought events took place from 1997 to 2003 in both Asia and North America. Severe drought events were more likely to occur during the summer on both continents. Asia had the most extreme drought events during July, but North America reached its highest drought frequency from June to September. In Asia, a persistent increasing trend of extreme drought emerged throughout the studied period. However,a more complex evolution of drought emerged in North America: a decreasing trend appeared before the mid-1960s and an increasing trend appeared after the late 1970s. A relatively steady dry/wet status was observed between the mid-1960s and the late 1970s. The role of exceptional, extreme drought events with respect to the La Nifia event was considered during 1997-2003.

  8. A mid to late Holocene cryptotephra framework from eastern North America

    Science.gov (United States)

    Mackay, Helen; Hughes, Paul D. M.; Jensen, Britta J. L.; Langdon, Pete G.; Pyne-O'Donnell, Sean D. F.; Plunkett, Gill; Froese, Duane G.; Coulter, Sarah; Gardner, James E.

    2016-01-01

    Holocene cryptotephras of Alaskan and Pacific Northwestern origin have recently been detected ca. 7000 km away on the east coast of North America. This study extends the emerging North American tephrochronological framework by geochemically characterising seventeen cryptotephra layers from four newly explored peatlands. All detected tephras were deposited during the late Holocene, with no horizons present in the peat between ca. 3000-5000 years ago. The prevalence of the Alaskan White River Ash eastern lobe (AD 847 ± 1) is confirmed across the eastern seaboard from Newfoundland to Maine and a regional depositional pattern from Mount St Helens Set W (AD 1479-1482) is presented. The first occurrences of four additional cryptotephras in eastern North America are described, three of which may originate from source regions in Mexico, Kamchatka (Russia) and Hokkaido (Japan). The possibility of such tephras reaching eastern North America presents the opportunity to link palaeo-archives from the tropics and eastern Asia with those from the western Atlantic seaboard, aiding inter-regional comparisons of proxy-climatic records.

  9. North Atlantic SST anomalies and the cold North European weather events of winter 2009/10 and December 2010

    OpenAIRE

    Buchan, Jian; Hirschi, Joel; Blaker, Adam; Sinha, Bablu

    2014-01-01

    Northern Europe experienced consecutive periods of extreme cold weather in the winter of 2009/2010 and in late 2010. These periods were characterised by a tripole pattern in North Atlantic sea surface temperature (SST) anomalies and exceptionally negative phases of the North Atlantic Oscillation (NAO). A global Ocean-Atmosphere General Circulation Model (OAGCM) is used to investigate the ocean’s role in influencing North Atlantic and European climate. Observed SST anomalies are used to force ...

  10. North Atlantic explosive cyclones and large scale atmospheric variability modes

    Science.gov (United States)

    Liberato, Margarida L. R.

    2015-04-01

    Extreme windstorms are one of the major natural catastrophes in the extratropics, one of the most costly natural hazards in Europe and are responsible for substantial economic damages and even fatalities. During the last decades Europe witnessed major damage from winter storms such as Lothar (December 1999), Kyrill (January 2007), Klaus (January 2009), Xynthia (February 2010), Gong (January 2013) and Stephanie (February 2014) which exhibited uncommon characteristics. In fact, most of these storms crossed the Atlantic in direction of Europe experiencing an explosive development at unusual lower latitudes along the edge of the dominant North Atlantic storm track and reaching Iberia with an uncommon intensity (Liberato et al., 2011; 2013; Liberato 2014). Results show that the explosive cyclogenesis process of most of these storms at such low latitudes is driven by: (i) the southerly displacement of a very strong polar jet stream; and (ii) the presence of an atmospheric river (AR), that is, by a (sub)tropical moisture export over the western and central (sub)tropical Atlantic which converges into the cyclogenesis region and then moves along with the storm towards Iberia. Previous studies have pointed to a link between the North Atlantic Oscillation (NAO) and intense European windstorms. On the other hand, the NAO exerts a decisive control on the average latitudinal location of the jet stream over the North Atlantic basin (Woollings et al. 2010). In this work the link between North Atlantic explosive cyclogenesis, atmospheric rivers and large scale atmospheric variability modes is reviewed and discussed. Liberato MLR (2014) The 19 January 2013 windstorm over the north Atlantic: Large-scale dynamics and impacts on Iberia. Weather and Climate Extremes, 5-6, 16-28. doi: 10.1016/j.wace.2014.06.002 Liberato MRL, Pinto JG, Trigo IF, Trigo RM. (2011) Klaus - an exceptional winter storm over Northern Iberia and Southern France. Weather 66:330-334. doi:10.1002/wea.755 Liberato

  11. Changing statistics of storms in the North Atlantic?

    International Nuclear Information System (INIS)

    Problems in the present discussion about increasing storminess in the North Atlantic area are discusesd. Observational data so far available do not indicate a change in the storm statistics. Output from climate models points to an itensified storm track in the North Atlantic, but because of the limited skill of present-day climate models in simulating high-frequency variability and regional details any such 'forecast' has to be considered with caution. A downscaling procedure which relates large-scale time-mean aspects of the state of the atmosphere and ocean to the local statistics of storms is proposed to reconstruct past variations of high-frequency variability in the atmosphere (storminess) and in the sea state (wave statistics). First results are presented. (orig.)

  12. The arctic mirage and the early north atlantic.

    Science.gov (United States)

    Sawatzky, H L; Lehn, W H

    1976-06-25

    The arctic mirage is a phenomenon that is common in higher latitudes. It occurs under conditions of pronounced temperature inversion, which impart to the air a refractive capability that may equal or exceed the curvature of the earth. Manifestations of the arctic mirage, though largely forgotten in modern times, are described in the earliest accounts of North Atlantic discovery. This interdisciplinary investigation, combining historical induction with scientific observation and analysis, has suggested a new interpretation of historical events. We believe that information gleaned from these mirages was vital to Norse navigation and exploration in the North Atlantic. We further contend that the mirage may furnish a logical basis for the pervasive ancient and medieval concept of the flat or saucer-shaped world. PMID:17739820

  13. A seasonal diary of phytoplankton in the North Atlantic

    DEFF Research Database (Denmark)

    Lindemann, Christian; St. John, Michael

    2014-01-01

    In recent years new biological and physical controls have been suggested to drive phytoplankton bloom dynamics in the North Atlantic. A better understanding of the mechanisms driving primary production has potentially important implications for the understanding of the biological carbon pump, as it...... are not mutually exclusive, but rather complementary. Thus, moving beyond the “single mechanism” point of view, here we present an integrated conceptual model of the physical and biological controls on phytoplankton dynamics in the North Atlantic. Further we believe that the acclimation of...... physiological rates can play an important role in mediating phytoplankton dynamics. Thus, this view emphasizes the occurrence of multiple controls and relates their variations in impact to climate change...

  14. Eddy length scales in the North Atlantic Ocean

    OpenAIRE

    Eden, Carsten

    2007-01-01

    Eddy length scales are calculated from satellite altimeter products and in an eddy-resolving model of the North Atlantic Ocean. Four different measures for eddy length scales are derived from kinetic energy densities in wave number space and spatial decorrelation scales. Observational estimates and model simulation agree well in all these measures near the surface. As found in previous studies, all length scales are, in general, decreasing with latitude. They are isotropic and proportional to...

  15. Statistical modelling of North Atlantic tropical cyclone tracks

    OpenAIRE

    Hall, Timothy M.; Jewson, Stephen

    2007-01-01

    We present a statistical model of North Atlantic tropical cyclone tracks from genesis site through lysis. To propagate tracks we use the means and variances of latitudinal and longitudinal displacements and model the remaining anomalies as autoregressive. Coefficients are determined by averaging near-neighbour historical track data, with ‘near’ determined optimally by using jackknife out-of-sample validation to maximize the likelihood of the observations. The number of cyclones in a simulated...

  16. Polar vortex controls coupling of North Atlantic Ocean and atmosphere

    OpenAIRE

    Graf, H; Walter, K.

    2005-01-01

    The structure of the North Atlantic leading atmospheric winter variability mode strongly depends on the state of the polar stratospheric vortex. If the polar vortex is strong, one teleconnection pattern emerges in the upper troposphere, while two mostly independent ones appear when the vortex is weak. The anomaly patterns associated with the different polarities of these modes show strong differences in the wind fields and in the correlation of atmospheric variability with the sea surface tem...

  17. Health outcomes among HIV-positive Latinos initiating antiretroviral therapy in North America versus Central and South America

    OpenAIRE

    Carina Cesar; Koethe, John R; Mark J Giganti; Peter Rebeiro; Althoff, Keri N; Sonia Napravnik; Angel Mayor; Beatriz Grinsztejn; Marcelo Wolff; Denis Padgett; Juan Sierra-Madero; Eduardo Gotuzzo; Sterling, Timothy R; James Willig; Julie Levison

    2016-01-01

    Introduction: Latinos living with HIV in the Americas share a common ethnic and cultural heritage. In North America, Latinos have a relatively high rate of new HIV infections but lower rates of engagement at all stages of the care continuum, whereas in Latin America antiretroviral therapy (ART) services continue to expand to meet treatment needs. In this analysis, we compare HIV treatment outcomes between Latinos receiving ART in North America versus Latin America. Methods: HIV-positive adult...

  18. Cenozoic uplift and subsidence in the North Atlantic region

    DEFF Research Database (Denmark)

    Anell, Ingrid Anna Margareta; Thybo, Hans; Artemieva, Irina

    2009-01-01

    the surrounding areas. (2) A regional increase in subsidence in the offshore marginal areas of Norway, the northern North Sea, the northern British Isles and west Greenland took place in the Eocene (ca 57-35 Ma). (3) The Oligocene and Miocene (35-5 Ma) were characterized by regional tectonic...... quiescence, with only localised uplift, probably related to changes in plate dynamics. (4) The second major phase of regional uplift that affected all marginal areas of the North Atlantic occurred in the Plio-Pleistocene (5-0 Ma). Its amplitude was enhanced by erosion-driven glacio-isostatic compensation...

  19. Water mass pathways to the North Atlantic oxygen minimum zone

    Science.gov (United States)

    Peña-Izquierdo, Jesús; van Sebille, Erik; Pelegrí, Josep L.; Sprintall, Janet; Mason, Evan; Llanillo, Pedro J.; Machín, Francisco

    2015-05-01

    The water mass pathways to the North Atlantic Oxygen Minimum Zone (naOMZ) are traditionally sketched within the cyclonic tropical circulation via the poleward branching from the eastward flowing jets that lie south of 10°N. However, our water mass analysis of historic hydrographic observations together with numerical Lagrangian experiments consistently reveal that the potential density level of σθ = 26.8 kg m-3 (σ26.8, approximately 300 m depth) separates two distinct regimes of circulation within the Central Water (CW) stratum of the naOMZ. In the upper CW (above σ26.8), and in agreement with previous studies, the supply of water mainly comes from the south with a predominant contribution of South Atlantic CW. In the lower CW (below σ26.8), where minimal oxygen content is found, the tropical pathway is instead drastically weakened in favor of a subtropical pathway. More than two thirds of the total water supply to this lower layer takes place north of 10°N, mainly via an eastward flow at 14°N and northern recirculations from the northern subtropical gyre. The existence of these northern jets explains the greater contribution of North Atlantic CW observed in the lower CW, making up to 50% of the water mass at the naOMZ core. The equatorward transfer of mass from the well-ventilated northern subtropical gyre emerges as an essential part of the ventilation of the naOMZ.

  20. Inventory of Atlantic White-Cedar Remnant Stands in North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report addresses Atlantic white cedar swamp restoration in North Carolina refuges. The ecology, use, and historical distribution of Atlantic white-cedar (AWC)...

  1. Inverted barometer contributions to recent sea level changes along the northeast coast of North America

    Science.gov (United States)

    Piecuch, Christopher G.; Ponte, Rui M.

    2015-07-01

    Regional sea level (SL) changes reflect dynamic and isostatic ocean effects. Recent works have interpreted accelerated and extreme SL changes along the northeast coast of North America primarily in terms of dynamic changes; however, dedicated study of isostatic changes related to surface atmospheric pressure loading—the inverted barometer (IB) effect—has been lacking. This investigation uses five different atmospheric pressure products to analyze the influence of the IB effect on annual mean SL from tide gauge records. The IB effect explains ˜25% of interannual SL variance and accounts for ˜50% of the magnitude of a recent extreme event of SL rise along Atlantic Canada and New England. Estimated IB effects also amount to ˜10-30% of recent multidecadal SL accelerations over the Mid-Atlantic Bight and Southern New England. These findings reiterate the need for careful estimation and removal of isostatic effects for studies of dynamic SL.

  2. Socially Engaged Buddhist Nuns: Activism in Taiwan and North America

    OpenAIRE

    Karma Lekshe Tsomo

    2015-01-01

    The last decades of the twentieth century have been a time of new visibility and social activism for Buddhists in Taiwan and around the world. This paper compares the social engagement of nuns in the Chinese Buddhist tradition in Taiwan and North America. I would like to argue that whereas nuns in Taiwan have developed a variety of approaches to social involvement, their counterparts in the Chinese diaspora in North America have had to face a set of challenges specific to overseas Chinese com...

  3. Summer precipitation anomalies in Asia and North America induced by Eurasian non-monsoon land heating versus ENSO

    Science.gov (United States)

    Zhao, Ping; Wang, Bin; Liu, Jiping; Zhou, Xiuji; Chen, Junming; Nan, Sulan; Liu, Ge; Xiao, Dong

    2016-02-01

    When floods ravage Asian monsoon regions in summer, megadroughts often attack extratropical North America, which feature an intercontinental contrasting precipitation anomaly between Asia and North America. However, the characteristics of the contrasting Asian-North American (CANA) precipitation anomalies and associated mechanisms have not been investigated specifically. In this article, we firmly establish this summer CANA pattern, providing evidence for a significant effect of the land surface thermal forcing over Eurasian non-monsoon regions on the CANA precipitation anomalies by observations and numerical experiments. We show that the origin of the CANA precipitation anomalies and associated anomalous anticyclones over the subtropical North Pacific and Atlantic has a deeper root in Eurasian non-monsoon land surface heating than in North American land surface heating. The ocean forcing from the ENSO is secondary and tends to be confined in the tropics. Our results have strong implications to interpretation of the feedback of global warming on hydrological cycle over Asia and North America. Under the projected global warming due to the anthropogenic forcing, the prominent surface warming over Eurasian non-monsoon regions is a robust feature which, through the mechanism discussed here, would favor a precipitation increase over Asian monsoon regions and a precipitation decrease over extratropical North America.

  4. Summer precipitation anomalies in Asia and North America induced by Eurasian non-monsoon land heating versus ENSO.

    Science.gov (United States)

    Zhao, Ping; Wang, Bin; Liu, Jiping; Zhou, Xiuji; Chen, Junming; Nan, Sulan; Liu, Ge; Xiao, Dong

    2016-01-01

    When floods ravage Asian monsoon regions in summer, megadroughts often attack extratropical North America, which feature an intercontinental contrasting precipitation anomaly between Asia and North America. However, the characteristics of the contrasting Asian-North American (CANA) precipitation anomalies and associated mechanisms have not been investigated specifically. In this article, we firmly establish this summer CANA pattern, providing evidence for a significant effect of the land surface thermal forcing over Eurasian non-monsoon regions on the CANA precipitation anomalies by observations and numerical experiments. We show that the origin of the CANA precipitation anomalies and associated anomalous anticyclones over the subtropical North Pacific and Atlantic has a deeper root in Eurasian non-monsoon land surface heating than in North American land surface heating. The ocean forcing from the ENSO is secondary and tends to be confined in the tropics. Our results have strong implications to interpretation of the feedback of global warming on hydrological cycle over Asia and North America. Under the projected global warming due to the anthropogenic forcing, the prominent surface warming over Eurasian non-monsoon regions is a robust feature which, through the mechanism discussed here, would favor a precipitation increase over Asian monsoon regions and a precipitation decrease over extratropical North America. PMID:26916258

  5. North Atlantic multidecadal variability in coupled climate models - Mechanisms and responses

    OpenAIRE

    Medhaug, Iselin

    2011-01-01

    Global atmosphere-ocean general circulation models have been used to investigate mechanisms controlling the North Atlantic low-frequency variability, with the focus on the Atlantic Meridional Overturning Circulation, the Subpolar Gyre dynamics and the North Atlantic basin scale sea surface temperatures, called the Atlantic Multidecadal Oscillation. The understanding of the dynamics of, and mechanisms behind the variability in these components of the climate system are of great ...

  6. Influence of the North Atlantic Oscillation on the Canary Islands precipitation

    OpenAIRE

    García Herrera, Ricardo; Gallego Puyol, David; Hernández Martín, Emiliano; Gimeno, Luis; Ribera Rodríguez, Pedro

    2001-01-01

    The aim of this paper is to investigate the relationship between the Canary Island rainfall and the Atlantic large-scale circulation, characterized by the North Atlantic oscillation (NAO) index. The Canary Islands are located in the Atlantic subtropical belt under the direct influence of the Azores high and the trade winds. Their steep orography makes the islands very sensitive to small variations in a synoptic situation, thus providing an excellent natural observatory for the North Atlantic ...

  7. The 8th Century Megadrought Across North America

    Science.gov (United States)

    Stahle, D. W.; Therrell, M. D.; Cleaveland, M. K.; Fye, F. K.; Cook, E. R.; Grissino-Mayer, H. D.; Acuna-Soto, R.

    2002-12-01

    Tree-ring data suggest that the 8th and 16th century megadroughts may have been the most severe and sustained droughts to impact North America in the past 1500 years. The 16th century megadrought may have persisted for up to 40 years, and extended from the tropics to the boreal forest and from the Pacific to Atlantic coasts. Evidence for the 8th century drought is sparse, but tree-ring and lake sediment data indicate that this drought extended from the northern Great Plains, across the southwestern United States, and into central Mexico and the Yucatan peninsula. Tree-ring data from Colorado and New Mexico document severe drought from A.D. 735-765, and may provide accurate and precise dating for the onset of the epic droughts reconstructed during the late first millennium A.D. with sedimentary data from Elk Lake, Minnesota; Moon Lake, South Dakota; La Piscina de Yuriria, Guanajuato; and Lake Chichancanab, Yucatan. If these chronological refinements are correct, then the sedimentary records suggest much greater persistence to the 8th century megadrought than indicated by the very high resolution tree-ring data, and a strong second pulse of prolonged drought late in the first millennium. Analyses of instrumental precipitation and drought indices during the 20th century, along with tree-ring reconstructions of climate in Mexico and the Southwest, indicate that annual and decadal droughts can both simultaneously impact the entire region from New Mexico and Texas down into central Mexico. The intensity and large-scale impact of drought across this region seem to be greatest when La Nina conditions and the low phase of the North Pacific oscillation prevail. The tree-ring dated 8th century megadrought occurred near the decline of the Classic Period civilizations at Teotihuacan in central Mexico and in the Mayan region of the Yucatan. The 8th century megadrought may have interacted with anthropogenic environmental degradation, epidemic disease, and social upheaval to

  8. Computer codes for birds of North America

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Purpose of paper was to provide a more useful way to provide codes for all North American species, thus making the list useful for virtually all projects concerning...

  9. Fuyao Aims for North America Expansion

    Institute of Scientific and Technical Information of China (English)

    JESSY ZHANG

    2006-01-01

    @@ China's auto-part industry has grown powerful enough to shake the world. Most recently, the acquisition attempt by a Chinese autoglass maker on a North Americac project shocked competitors.Fuyao Glass, China's largest and the world's sixth largest autoglass maker, announced thatthey have now entered the final stage of acqtuiring the North American glass-making assets of Ford Motor Co. which has been struggling through a painful restructuring.

  10. Timing of migratory baleen whales at the Azores in relation to the North Atlantic spring bloom

    NARCIS (Netherlands)

    F. Visser; K.L. Hartman; G.J. Pierce; V.D. Valavanis; J. Huisman

    2011-01-01

    Each year, a phytoplankton spring bloom starts just north of the North Atlantic Subtropical Gyre, and then expands northwards across the entire North Atlantic. Here, we investigate whether the timing of the spring migration of baleen whales is related to the timing of the phytoplankton spring bloom,

  11. Recent advances in the compilation of holocene relative Sea-level database in North America

    Science.gov (United States)

    Horton, B.; Vacchi, M.; Engelhart, S. E.; Nikitina, D.

    2015-12-01

    Reconstruction of relative sea level (RSL) has implications for investigation of crustal movements, calibration of earth rheology models and the reconstruction of ice sheets. In recent years, efforts were made to create RSL databases following a standardized methodology. These regional databases provided a framework for developing our understanding of the primary mechanisms of RSL change since the Last Glacial Maximum and a long-term baseline against which to gauge changes in sea-level during the 20th century and forecasts for the 21st. Here we present two quality-controlled Holocene RSL database compiled for North America. Along the Pacific coast of North America (British Columbia, Canada to California, USA), our re-evaluation of sea-level indicators from geological and archaeological investigations yield 841 RSL data-points mainly from salt and freshwater wetlands or adjacent estuarine sediment as well as from isolation basin. Along the Atlantic coast of North America (Hudson Bay, Canada to South Carolina, USA), we are currently compiling a database including more than 2000 RSL data-points from isolation basin, salt and freshwater wetlands, beach ridges and intratidal deposits. We outline the difficulties and solutions we made to compile databases in such different depostional environment. We address complex tectonics and the framework to compare such large variability of RSL data-point. We discuss the implications of our results for the glacio-isostatic adjustment (GIA) models in the two studied regions.

  12. Hydrogeology in North America: past and future

    Science.gov (United States)

    Narasimhan, T. N.

    2005-03-01

    This paper is a retrospective on the evolution of hydrogeology in North America over the past two centuries, and a brief speculation of its future. The history of hydrogeology is marked by developments in many different fields such as groundwater hydrology, soil mechanics, soil science, economic geology, petroleum engineering, structural geology, geochemistry, geophysics, marine geology, and more recently, ecology. The field has been enriched by the contributions of distinguished researchers from all these fields. At present, hydrogeology is in transition from a state of discovering new resources and exploiting them efficiently for maximum benefit, to one of judicious management of finite, interconnected resources that are vital for the sustenance of humans and other living things. The future of hydrogeology is likely to be dictated by the subtle balance with which the hydrological, erosional, and nutritional cycles function, and the decision of a technological society to either adapt to the constraints imposed by the balance, or to continue to exploit hydrogeological systems for maximum benefit. Although there is now a trend towards ecological and environmental awareness, human attitudes could change should large parts of the populated world be subjected to the stresses of droughts that last for many decades. Cet article est une rétrospective de l'évolution de l'hydrogéologie en Amérique du Nord sur les deux derniers siècles, et une brève évaluation de son futur. L'histoire de l'hydrogéologie est marquée par le développement de plusieurs techniques de terrain telles, l'hydrologie des eaux souterraines, la mécanique des sols, les sciences du sol, la géologie économique, l' ingénierie pétrolière, la géologie structurale, la géochimie, la géophysique, la géologie marine et plus récemment l'écologie. La science a été enrichie par la contribution de plusieurs chercheurs distingués, provenant de toutes ces branches. A présent, l

  13. Effects of aerosols on precipitation in north-eastern North America

    Directory of Open Access Journals (Sweden)

    R. Mashayekhi

    2013-10-01

    Full Text Available The changes in precipitation over north-eastern North America caused by chemistry – and particularly anthropogenic aerosols – are investigated using the Chemistry version of the Weather Research and Forecasting (WRF/Chem v3.4 model. The simulations were carried out for a five-month period from April to August 2009. The model results show that non-negligible changes in both convective and cloud-resolved (non-convective precipitation are caused by chemistry and/or aerosols over most parts of the domain. The changes can be attributed to both radiative and microphysical interactions with the meteorology. A chemistry-induced change of approximately −15% is found in the five-month mean daily convective precipitation over areas with high convective rain; most of this can be traced to radiative effects. Although, total non-convective rain is less than total convective rain in the domain, chemistry-induced effects on the former are more pronounced than those on the latter. A chemistry-induced increase of about +30% is evident in the five-month mean daily non-convective precipitation over the heavily urbanized parts of the Atlantic coast. The effects of aerosols on cloud microphysics and precipitation were examined for two particle size ranges: 0.039–0.1 μm and 1–2.5 μm. Strongly positive spatial correlation between cloud droplet number and non-convective rain are found for activated (cloud-borne aerosols in both size ranges. Non-activated (interstitial aerosols have a positive correlation with cloud droplet number and non-convective rain when they are small and an inverse correlation for larger particles.

  14. Cortinarius bovarius (Agaricales, a new species from western North America

    Directory of Open Access Journals (Sweden)

    Kare Liimatainen

    2013-05-01

    Full Text Available Cortinarius bovarius sp. nov., a conifer associated taxon growing on calcareous ground, is described from western North America. Phylogenetic relationships and species limits were investigated using rDNA ITS and nuclear rpb2 sequences, morphological and ecological data. The species belongs to section Bovini and its closest relative is European C. bovinus.

  15. Aridland Springs in North America: Ecology and Conservation

    OpenAIRE

    Kate Smith

    2012-01-01

    Review of Aridland Springs in North America: Ecology and Conservation. Lawrence E. Stevens and Vicky J. Meretsky, editors. 2008. The University of Arizona Press and the Arizona‐SonoraDesert Museum, Tucson.Pp. 406, 4 black‐and‐white photos, 28 illustrations, 38 tables, 8 maps, bibliography.$75.00 (cloth). ISBN 978‐0‐8165‐2645‐1.

  16. PARASITES OF FRESHWATER FISHES IN NORTH AMERICA: WHY SO NEGLECTED?

    Czech Academy of Sciences Publication Activity Database

    Scholz, Tomáš; Choudhury, A.

    2014-01-01

    Roč. 100, č. 1 (2014), s. 26-45. ISSN 0022-3395 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Trematode * North America * Cestoda * Acanthocephala * Digenea Subject RIV: EG - Zoology Impact factor: 1.227, year: 2014

  17. Key Challenges to Collegiate Music Education Programs in North America

    Science.gov (United States)

    Jones, Patrick M.

    2012-01-01

    Higher education is the linchpin of music education in North America. It is primarily in collegiate institutions that music teachers are educated throughout the life cycles of their careers. This begins with preservice programs, typically at the baccalaureate level, and continues with in-service professional development and graduate degree…

  18. New digital magnetic anomaly database for North America

    Science.gov (United States)

    Finn, C.A.; Pilkington, M.; Cuevas, A.; Hernandez, I.; Urrutia, J.

    2001-01-01

    The Geological Survey of Canada (GSC), U.S. Geological Survey (USGS), and Consejo de Recursos Minerales of Mexico (CRM) are compiling an upgraded digital magnetic anomaly database and map for North America. This trinational project is expected to be completed by late 2002.

  19. Bermuda Contribution to a North Atlantic Aerobiology Study

    Science.gov (United States)

    2003-01-01

    The primary aim of this project, a 6-month effort that commenced October 1 2002 (with no-cost extension until September 30 2003) was to collect a weekly time series of marine aerosol samples at Bermuda for the enumeration, culture and characterization of microbes, particularly those associated with soil dust and other aerosol particles originating from North Africa, North America, and Asia. Such airborne microbes may play important roles as pathogens, and also in the large-scale biogeochemical exchange between land, atmosphere and ocean.

  20. Radium 226 in the deep north-eastern Atlantic Ocean

    International Nuclear Information System (INIS)

    With reference to the distribution of radium-226 in the western equatorial and north-eastern deep Atlantic Ocean it was possible to establish structures in the correlations of radium-226 to its chemical homologue Ba and dissolved SiO2. An 11-box model of the deep Atlantic Ocean was used to obtain information on the size of the radium-226 and Ba sources. The soil source derives mainly from the dissolution of barite. For the first time, an evaluation of the radium-226 flow resulting from the dissolution of particulate matter is presented. The box model and the radium-226 concentrations measured put down the value as 23-46·10-21 mol/m2s. (DG)

  1. Shale gas in North America and Europe

    OpenAIRE

    MICHAEL H. STEPHENSON

    2016-01-01

    According to the U.S. Energy Information Administration, shale gas will provide half of the United States’ domestic gas by 2035. The United States has already moved from being one of the world's largest importers of gas to being self-sufficient in less than a decade, bringing hundreds of thousands of jobs and attracting back companies that long ago left America in search of cheap manufacturing costs. But the increase in shale gas extraction has also had an environmental cost. There is clear s...

  2. Lianas as invasive species in North America: Chapter 28

    Science.gov (United States)

    Leicht-Young, Stacey A.; Pavlovic, Noel B.

    2015-01-01

    Liana diversity is typically low in the temperate zones; however, the influx of non-native invasive liana species in North America has increased local diversity at the expense of native habitats and species. Some of the most illustrative studies of invasive lianas in temperate North America compared the biological traits of invasive lianas with native congeners or ecological analogs. The majority of these studies focused on two species, Celastrus orbiculatus (oriental bittersweet) and Lonicera japonica (Japanese honeysuckle). Temperate zone lianas generally have higher photosynthetic rates than other early successional species and their host trees. Invasive lianas are having an increasing impact on the dynamics and trajectories of North American plant communities. They often exhibit superior growth and survival compared to their native counterparts, and in some cases, invasive lianas may directly contribute to the decline of their native correlates.

  3. South Atlantic Bight Habitat Mapping on NOAA Ship Nancy Foster in North Atlantic Ocean between 20070626 and 20070702

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This expedition on the NOAA Ship Nancy Foster used the recently-developed National Undersea Research Center for the North Atlantic and Great Lakes (NURC-NAGL) ROV...

  4. Current velocity and hydrographic observations in the Southwestern North Atlantic Ocean: Subtropical Atlantic Climate Studies (STACS), 1989 (NODC Accession 9100033)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The primary objective of the STACS program are to increase our understanding of the dynamics of the North Atlantic circulation and the role of the ocean circulation...

  5. Oxygen trends over five decades in the North Atlantic

    Science.gov (United States)

    Stendardo, I.; Gruber, N.

    2012-11-01

    We investigate long-term trends in dissolved oxygen in the North Atlantic from 1960 to 2009 on the basis of a newly assembled high-quality dataset consisting of oxygen data from three different sources: CARINA, GLODAP and the World Ocean Database. Oxygen trends are determined along isopycnal surfaces for eight regions and five water masses using a general least-squares linear regression method that accounts for temporal auto-correlation. Our results show a significant decrease of oxygen in the Upper (UW), Mode (MW) and Intermediate (IW) waters in almost all regions over the last 5 decades. Over the same period, oxygen increased in the Lower Intermediate Water (LIW) and Labrador Sea Water (LSW) throughout the North Atlantic. The observed oxygen decreases in the MW and IW of the northern and eastern regions are largely driven by changes in circulation and/or ventilation, while changes in solubility are the main driver for the oxygen decrease in the UW and the increases in the LIW and LSW. From 1960 until 2009 the UW, MW, and IW horizons have lost a total of -57 ± 34 Tmol, while the LIW and LSW horizons have gained 46 ± 47 Tmol, integrating to a roughly constant oxygen inventory in the North Atlantic. Comparing our oxygen trends with those of the oceanic heat content, we find an O2 to heat change ratio of -3.6 ± 2.8 nmol J-1 for the UW, MW and IW, and a ratio of -2.8 ± 3.4 nmol J-1 for the LIW and LSW. These ratios are substantially larger than those expected from solubility alone.

  6. Observed trends of anthropogenic acidification in North Atlantic water masses

    Directory of Open Access Journals (Sweden)

    M. Vázquez-Rodríguez

    2012-03-01

    Full Text Available The lack of observational pH data has made difficult assessing recent rates of ocean acidification, particularly in the high latitudes. Here we present a time series of high-quality carbon system measurements in the North Atlantic, comprising fourteen cruises spanning over 27 yr (1981–2008 and covering important water mass formation areas like the Irminger and Iceland basins. We provide direct quantification of anthropogenic acidification rates in upper and intermediate North Atlantic waters by removing the natural variability of pH from the observations. Bottle data were normalised to basin-average conditions using climatological data and further condensed into averages per water mass and year to examine the temporal trends. The highest acidification rates of all inspected water masses were associated with surface waters in the Irminger Sea (−0.0018 ± 0.0001 yr−1 and the Iceland Basin (−0.0012 ± 0.0002 yr−1 and, unexpectedly, with Labrador Seawater (LSW which experienced an unprecedented pH drop of −0.0015 ± 0.001 yr−1. The latter stems from the formation by deep convection and the rapid propagation in the North Atlantic subpolar gyre of this well-ventilated water mass. The high concentrations of anthropogenic CO2 are effectively transported from the surface into intermediate waters faster than via downward diffusion, thus accelerating the acidification rates of LSW. An extrapolation of the observed lineal trends of acidification suggests that the pH of LSW could drop 0.45 units with respect to pre-industrial levels by the time atmospheric CO2 concentrations double the present ones.

  7. A Holocene Database of Relative Sea Levels for North America and the Caribbean: Implications for Geophysical Models

    Science.gov (United States)

    Engelhart, S. E.; Peltier, W. R.; Horton, B. P.; Khan, N. S.; Liu, S.; Vacchi, M.

    2011-12-01

    We have expanded the previously available quality-controlled database of relative sea-level (RSL) observations for the U.S. Atlantic coast with data from the Atlantic coast of Canada, the Pacific coast of North America and the Caribbean. The Holocene sea-level database for the U.S. Atlantic coast consisted of 836 sea-level indicators. The database documented a decreasing rate of relative sea-level (RSL) rise through time with no evidence of sea level being above present in the middle to late Holocene. The highest rates of rise were found in the mid-Atlantic region. We employed the database to constrain an ensemble of glacial isostatic adjustment (GIA) models using two ice (ICE-5G and ICE-6G) and two mantle viscosity variation (VM5a and VM5b). We identified significant misfits between observations and predictions using ICE-5G with the VM5a viscosity profile. ICE-6G provides some improvement for the northern Atlantic region, but misfits remain elsewhere. Decreasing the upper mantle and transition zone viscosity from 0.5*1021 Pa s (VM5a) to 0.25*1021 Pa s (VM5b) removed significant discrepancies between observations and predictions along the mid-Atlantic coastline, although misfits remained in the southern Atlantic region. The addition of new data from areas more proximal and distal to Laurentide ice loading has allowed us to further investigate the VM5b mantle viscosity profile.

  8. Liquefied natural gas : North America's introduction to an emerging world gas market

    International Nuclear Information System (INIS)

    The background of liquefied natural gas (LNG) and the market for LNG was presented along with illustrative examples of capital expenditure profiles for selected LNG projects. Investment outside the North American market for LNG, and long term LNG contracts were also discussed along with the growth rate of LNG. The author also presented a historical and forecast chart of firm, probable and possible LNG liquefaction capacity by region as well as a chart of regional destination of new LNG contract supplies from operating, firm and probable liquefaction plants in the Atlantic Basin and the Middle East. Other charts included contractual dedication to North American markets from operating, firm and probable liquefaction plants compared with actual and similar charts for European and Asian markets. A comparison of United States LNG terminal imports with capacity was also illustrated. Netbacks for selected Atlantic Basin arbitrage patterns from Trinidad and Nigeria to Spain and the United States Gulf Coast and netbacks from the United States Gulf Coast, Spain and Japan to the Middle East showing arbitrage patterns were also presented. The presentation concluded that North America faces a new era in gas supply as it moves to supplement continental resources with LNG imports from world markets. tabs., figs

  9. Seabirds of the Atlantic Frontier, north and west of Scotland

    Science.gov (United States)

    Reid, James B.; Pollock, Claire M.; Mavor, Roddy

    2001-05-01

    The marine environment of the Atlantic Frontier region north and west of Scotland, the focus of recent oil exploration, hosts internationally important concentrations of seabirds. Twenty-three species breed in colonies on the coasts and islands that rise from these waters and a further 25 species use them for feeding at various times of the year. The importance of these populations are set in an international context and their composition and occurrence in the deep waters of the Atlantic Frontier and adjacent continental shelf waters, as revealed by 20 years of at-sea surveys, is described. Deep waters are especially important for procellariiformes whereas shelf waters are important for all species, and overall seabird diversity is greater in shelf waters. The effects of oil pollution on seabirds can be severe, and although the effect of pollution in deep, oceanic waters might be minimal, prevailing currents and winds might result in greater impacts on more westerly, shelf waters. While the perceived threats from oil exploration in the Atlantic Frontier might be small the important seabird assemblage in the region should be considered in future exploitation of hydrocarbons here.

  10. North Atlantic migratory bird flyways provide routes for intercontinental movement of avian influenza viruses

    Science.gov (United States)

    Dusek, Robert J.; Hallgrimsson, Gunnar T.; Ip, Hon S.; Jónsson, Jón E.; Sreevatsan, Srinand; Nashold, Sean W.; TeSlaa, Joshua L.; Enomoto, Shinichiro; Halpin, Rebecca A.; Lin, Xudong; Federova, Nadia; Stockwell, Timothy B.; Dugan, Vivien G.; Wentworth, David E.; Hall, Jeffrey S.

    2014-01-01

    Avian influenza virus (AIV) in wild birds has been of increasing interest over the last decade due to the emergence of AIVs that cause significant disease and mortality in both poultry and humans. While research clearly demonstrates that AIVs can move across the Pacific or Atlantic Ocean, there has been no data to support the mechanism of how this occurs. In spring and autumn of 2010 and autumn of 2011 we obtained cloacal swab samples from 1078 waterfowl, gulls, and shorebirds of various species in southwest and west Iceland and tested them for AIV. From these, we isolated and fully sequenced the genomes of 29 AIVs from wild caught gulls (Charadriiformes) and waterfowl (Anseriformes) in Iceland. We detected viruses that were entirely (8 of 8 genomic segments) of American lineage, viruses that were entirely of Eurasian lineage, and viruses with mixed American-Eurasian lineage. Prior to this work only 2 AIVs had been reported from wild birds in Iceland and only the sequence from one segment was available in GenBank. This is the first report of finding AIVs of entirely American lineage and Eurasian lineage, as well as reassortant viruses, together in the same geographic location. Our study demonstrates the importance of the North Atlantic as a corridor for the movement of AIVs between Europe and North America.

  11. A magmatic probe of dynamic topography beneath western North America

    Science.gov (United States)

    Klöcking, M.; White, N. J.; Maclennan, J.

    2014-12-01

    A region centered on the Yellowstone hotspot and encompassing the Colorado Plateau sits at an elevation 2 km higher than the cratonic North America. This difference broadly coincides with tomographically observed variations in lithospheric thickness: ~120 km beneath western North America, ~240 km beneath the craton. Thermochronology of the Grand Canyon area, sedimentary flux to the Gulf of Mexico, and river profile inversion all suggest that regional uplift occurred in at least two separate stages. High resolution seismic tomographic models, using USArray data, have identified a ring of low velocity material beneath the edges of the Colorado Plateau. Magmatism coincides with these low velocity zones and shows distinct phases: an overall increase in volume around 40 Ma and a change from lithospheric to asthenospheric signatures around 5 Ma. Volcanism is also observed to migrate north-east with time. Here, we attempt to integrate these different observations with lithospheric thickness. A dynamic topography model of progressive lithospheric erosion over a hot mantle plume might account for uplift as well as the temporal and spatial distribution of magmatism across western North America. Thinning of the lithosphere around the edges of the Colorado Plateau in combination with the hotter mantle potential temperature of a plume could create isostatic and dynamic uplift as well as allowing for melt production. To test this model, we have analysed around 100 samples from volcanic centers across western North America by ICP-MS for rare earth elements (REE). Most of the samples are younger than 5 Ma, and all of them have previously been analysed by XRF. Using trace element ratios such as La/Yb and Nb/Y we assess depth of melting and melt fraction, respectively. In addition, we use REE inversion modelling to estimate melt fractions as a function of depth and temperature of melting. The results are compared to existing constraints on lithospheric thickness and mantle potential

  12. Cortinarius section Sanguinei in North America.

    Science.gov (United States)

    Niskanen, Tuula; Liimatainen, Kare; Ammirati, Joseph F; Hughes, Karen

    2013-01-01

    The North American species of Cortinarius section Sanguinei were studied using morphological characters and ITS and RPB2 sequence data. Several type collections also were examined. Four species were identified: C. harrisonii sp. nov, C. neosanguineus sp. nov., C. sanguineus and C. sierraensis comb. nov. Of these, C. sanguineus also occurs in Europe together with C. puniceus, a fifth member of the section. Typical features of these species include ± red, fairly small basidiomata, stipe basal mycelium often with yellow to reddish yellow tints, amygdaloid to ellipsoid spores, and aniline-red lamellar trama and pileipellis hyphae when mounted in KOH. Two other species with red lamellae C. marylandensis comb. nov. and C. smithii stat. nov. & nom. nov. also are discussed. PMID:22962360

  13. Initializing decadal climate predictions over the North Atlantic region

    Science.gov (United States)

    Matei, Daniela Mihaela; Pohlmann, Holger; Jungclaus, Johann; Müller, Wolfgang; Haak, Helmuth; Marotzke, Jochem

    2010-05-01

    Decadal climate prediction aims to predict the internally-generated decadal climate variability in addition to externally-forced climate change signal. In order to achieve this it is necessary to start the predictions from the current climate state. In this study we investigate the forecast skill of the North Atlantic decadal climate predictions using two different ocean initialization strategies. First we apply an assimilation of ocean synthesis data provided by the GECCO project (Köhl and Stammer, 2008) as initial conditions for the coupled model ECHAM5/MPI-OM. Hindcast experiments are then performed over the period 1952-2001. An alternative approach is one in which the subsurface ocean temperature and salinity are diagnosed from an ensemble of ocean model runs forced by the NCEP-NCAR atmospheric reanalyzes for the period 1948-2007, then nudge into the coupled model to produce initial conditions for the hindcast experiments. An anomaly coupling scheme is used in both approaches to avoid the hindcast drift and the associated initial shock. Differences between the two assimilation approaches are discussed by comparing them with the observational data in key regions and processes. We asses the skill of the initialized decadal hindcast experiments against the prediction skill of the non-initialized hindcasts simulation. We obtain an overview of the regions with the highest predictability from the regional distribution of the anomaly correlation coefficients and RMSE for the SAT. For the first year the hindcast skill is increased over almost all ocean regions in the NCEP-forced approach. This increase in the hindcast skill for the 1 year lead time is somewhat reduced in the GECCO approach. At lead time 5yr and 10yr, the skill enhancement is still found over the North Atlantic and North Pacific regions. We also consider the potential predictability of the Atlantic Meridional Overturning Circulation (AMOC) and Nordic Seas Overflow by comparing the predicted values to

  14. Blue whale (Balaenoptera musculus) sounds from the North Atlantic

    Science.gov (United States)

    Mellinger, David K.; Clark, Christopher W.

    2003-08-01

    Sounds of blue whales were recorded from U.S. Navy hydrophone arrays in the North Atlantic. The most common signals were long, patterned sequences of very-low-frequency sounds in the 15-20 Hz band. Sounds within a sequence were hierarchically organized into phrases consisting of one or two different sound types. Sequences were typically composed of two-part phrases repeated every 73 s: a constant-frequency tonal ``A'' part lasting approximately 8 s, followed 5 s later by a frequency-modulated ``B'' part lasting approximately 11 s. A common sequence variant consisted only of repetitions of part A. Sequences were separated by silent periods averaging just over four minutes. Two other sound types are described: a 2-5 s tone at 9 Hz, and a 5-7s inflected tone that swept up in frequency to ca. 70 Hz and then rapidly down to 25 Hz. The general characteristics of repeated sequences of simple combinations of long-duration, very-low-frequency sound units repeated every 1-2 min are typical of blue whale sounds recorded in other parts of the world. However, the specific frequency, duration, and repetition interval features of these North Atlantic sounds are different than those reported from other regions, lending further support to the notion that geographically separate blue whale populations have distinctive acoustic displays.

  15. 48 CFR 225.871 - North Atlantic Treaty Organization (NATO) cooperative projects.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false North Atlantic Treaty Organization (NATO) cooperative projects. 225.871 Section 225.871 Federal Acquisition Regulations System... Other International Agreements and Coordination 225.871 North Atlantic Treaty Organization...

  16. 50 CFR 224.105 - Speed restrictions to protect North Atlantic Right Whales.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Speed restrictions to protect North Atlantic Right Whales. 224.105 Section 224.105 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE... AND ANADROMOUS SPECIES § 224.105 Speed restrictions to protect North Atlantic Right Whales. (a)...

  17. Elemental composition of air masses under different altitudes in Azores, central north Atlantic

    International Nuclear Information System (INIS)

    Between 8th July 2002 and 18th June 2004, aerosol samples were collected in Azores. Their inorganic composition was obtained by neutron activation analysis in order to study the differences of aerosols in two atmospheric altitudes of the central north Atlantic: (1) PICO-NARE observatory (Lower Free Troposphere-LFT) at Pico mountain summit (38,470 deg N, 28,404 deg W, 2,225 m a.s.l.) in Pico Island, Azores, where air masses from the surrounding continents (Africa, Europe, Central and North America) pass through, carrying aerosols with anthropogenic (Sb, Br, Mo, U, Se and Tb) and/or natural emissions (Fe, Co, La, Na, Sm, Cr, Zn, Hf, K and Th); (2) TERCEIRA-NARE station (Marine Boundary Layer) at Serreta (38,69 deg N, 27,36 deg W, 50 m a.s.l.), in Terceira Island, Azores, where natural aerosols (I, Cl, Na, Br and other soil related elements) are predominant. However, a combined interpretation of the data points out to a co-existence of the anthropogenic elements Sb and Mo, eventually with similar origins as the ones passing Pico Mountain summit. Very high concentrations and enrichment factors for Sb, Mo and Br in LFT, higher than the ones found in other areas, confirm atmospheric long-range transport mainly from the west boundary of north Atlantic; this may indicate eventual accumulation and persistence of those elements in the area due to the presence of Azores high pressures or the Hadley cells effect. A significant correlation between Fe and Yb and the enrichment of rare earth elements (La, Sm, Tb and Yb) and Th in LFT aerosols, both reflect a mineral dust intrusions from north Africa (Sahara and Sahel region). (author)

  18. Emigrated neuroscientists from Berlin to North America.

    Science.gov (United States)

    Holdorff, Bernd

    2016-01-01

    The highest number of German scholars and physicians, forced by the National Socialist regime to emigrate for "race" or political reasons, were from Berlin. Language and medical exams were requested differently in their new host country-the United States-leading to a concentration of immigrants in the New York and Boston areas. Very early Emergency Committees in Aid of German Scholars and Physicians were established. Undergraduate students (like F. A. Freyhan, H. Lehmann, and H.-L. Teuber) from Berlin seemed to integrate easily, in contrast to colleagues of more advanced age. Some of the former chiefs and senior assistants of Berlin's neurological departments could achieve a successful resettlement (C. E. Benda, E. Haase, C. F. List, and F. Quadfasel) and some a minor degree of success (F. H. Lewy and K. Goldstein). A group of neuropsychiatrists from Bonhoeffer's staff at the Berlin Charité Hospital could rely on the forceful intercession of their former chief. The impact of the émigré colleagues on North American neuroscience is traced in some cases. Apart from the influential field of psychoanalysis, a more diffuse infiltration of German and European neuropsychiatry may be assumed. The contribution to the postwar blossoming of neuropsychology by the émigré neuroscientists K. Goldstein, F. Quadfasel, and H.-L. Teuber is demonstrated in this article. PMID:26853762

  19. Analysis of the Remote Access Market in North America

    OpenAIRE

    Björk, Mikael; Blanc, Dominique

    2012-01-01

    How can a small European technology company make it to the giant North American market? This thesis deals with how a new entrant with disruptive technologies and products in the remote access automation market could enter and develop a business in North America where this market barely exists. To address this problem, we have analyzed if the Porter Five Force framework together with the Blue Ocean concept is a viable approach to evaluate a company’s competitive edge, and what strategy to appl...

  20. Natural gas pricing and contracting practices in North America

    International Nuclear Information System (INIS)

    Over the past 5 years the natural gas industry in North America has undergone substantial change as a result of the deregulated market. A comparison is provided of the key contract parameters in gas purchase contracts utilized by local distribution companies, industrial customers, cogenerators and marketers. Issues discussed include pricing mechanisms, indexed contracts, negotiated contracts, combinations, dispute resolution, supply, government regulation, industry structures, financial considerations, perception, geological influences, demand, transmission, storage, distribution, price trends and forecasts, Order 636 in the U.S., the evolution of North American market hubs, the futures market, and 'daisy chains' of connecting pipelines. 15 refs., 7 figs., 1 tab

  1. Detection of group 1 coronaviruses in bats in North America

    Science.gov (United States)

    Dominguez, S.R.; O'Shea, T.J.; Oko, L.M.; Holmes, K.V.

    2007-01-01

    The epidemic of severe acute respiratory syndrome (SARS) was caused by a newly emerged coronavirus (SARS-CoV). Bats of several species in southern People's Republic of China harbor SARS-like CoVs and may be reservoir hosts for them. To determine whether bats in North America also harbor coronaviruses, we used reverse transcription-PCR to detect coronavirus RNA in bats. We found coronavirus RNA in 6 of 28 fecal specimens from bats of 2 of 7 species tested. The prevalence of viral RNA shedding was high: 17% in Eptesicus fuscus and 50% in Myotis occultus. Sequence analysis of a 440-bp amplicon in gene 1b showed that these Rocky Mountain bat coronaviruses formed 3 clusters in phylogenetic group 1 that were distinct from group 1 coronaviruses of Asian bats. Because of the potential for bat coronaviruses to cause disease in humans and animals, further surveillance and characterization of bat coronaviruses in North America are needed.

  2. Social Pedagogy in North America: historical background and current developments

    Directory of Open Access Journals (Sweden)

    Daniel Schugurensky

    2015-12-01

    Full Text Available In North America, the use of the term ‘social pedagogy’ is a relatively new phenomenon, but social pedagogical practices have been used for a long time. The recent interest in the field of social pedagogy can be explained in part by the publication of an unprecedented volume of books and articles in English language, the creation of a new international journal, the simultaneous development of graduate programs in social pedagogy in the UK and the USA, and the establishment of a social pedagogy association that brings together academics and practitioners. In North America, social pedagogy thinking is influenced by the history of the field, by current social pedagogy theory and practice in other parts of the world, and by several traditions that connect education with social change. The paper discusses ten of them: indigenous education, progressive education, social movement learning, community development, public pedagogy, popular education, participatory action research, social economy, participatory democracy, and critical theory. 

  3. Aerosol Daytime Variations over North and South America Derived from Multiyear AERONET Measurements

    Science.gov (United States)

    Zhang, Yan; Yu, Hongbin; Eck, Tom F.; Smirnov, Alexander; Chin, Mian; Remer, Lorraine A.; Bian, Huisheng; Tan, Qian; Levy, Roberrt; Holben, Brent N.

    2012-01-01

    This study analyzes the daytime variation of aerosol with seasonal distinction by using multi-year measurements from 54 of the Aerosol Robotic Network (AERONET) sites over North America, South America, and islands in surrounding oceans. The analysis shows a wide range of daily variability of aerosol optical depth (AOO) and Angstrom exponent depending on location and season. Possible reasons for daytime variations are given. The largest AOO daytime variation range at 440 nm, up to 75%, occurs in Mexico City, with maximum AOO in the afternoon. Large AOO daily variations are also observed in the polluted mid-Atlantic U.S. and U.S. West Coast with maximum AOO occurring in the afternoon in the mid-Atlantic U.S., but in the morning in the West Coast. In South American sites during the biomass burning season (August to October), maximum AOO generally occurs in the afternoon. But the daytime variation becomes smaller when sites are influenced more by long-range transported smoke than by local burning. Islands show minimum AOO in the morning and maximum AOO in the afternoon. The diverse patterns of aerosol daytime variation suggest that geostationary satellite measurements would be invaluable for characterizing aerosol temporal variations on regional and continental scales. In particular, simultaneous measurements of aerosols and aerosol precursors from a geostationary satellite would greatly aid in understanding the evolution of aerosol as determined by emissions, chemical transformations, and transport processes.

  4. Yochelcionella (Mollusca, Helcionelloida) from the lower Cambrian of North America

    OpenAIRE

    Atkins C J; Peel J S

    2008-01-01

    Five named species of the helcionelloid mollusc genus Yochelcionella Runnegar & Pojeta, 1974 are recognized from the lower Cambrian (Cambrian Series 2) of North America: Yochelcionella erecta (Walcott, 1891), Y. americana Runnegar &Pojeta, 1980, Y. chinensis Pei, 1985, Y. greenlandica Atkins & Peel, 2004 and Y. gracilis Atkins & Peel, 2004, linking lower Cambrian o...

  5. A refugee's perspective on their neurosurgical care in North America

    OpenAIRE

    C Michael Honey; Anujan Poologaindran; Maureen Mayhew; Laura Vander Steen; Christopher Charles Gillis

    2015-01-01

    Background: There is a growing population of refugees within North America and an increasing awareness of their unique medical requirements. These requirements include both a well-recognized need to understand the different pathologies that can present in these patients as well as the rarely described need to understand their unique perspective and how this can impact their medical care, especially for routine neurosurgical conditions. This paper highlights a refugee′s perspective toward the ...

  6. North America: Multiplying media in a dynamic landscape

    OpenAIRE

    Eid, Mahmoud; Buchanan, Carrie

    2005-01-01

    Perhaps no region on earth has been as affected by the dramatic pace and extent of media development since 1990 as North America, where most have ready access to new media, such as the Internet and the latest telecommunications devices, as well as the traditional newspapers, radio and television. Even traditional media have undergone profound change as convergence and cross–ownership brought them together in vast media conglomerates dominated by a handful of global corporations. Digitization ...

  7. Helminth parasites of the osprey, Pandion haliaetus, in North America

    Science.gov (United States)

    Kinsella, J.M.; Cole, Rebecca A.; Forrester, Donald J.; Roderick, Constance L.

    1996-01-01

    A total of 28 species of helminths (17 trematodes, 3 cestodes, 7 nematodes, and 1 acanthocephalan) was recovered from 17 ospreys (Pandion haliaetus) from the United States. Intensities of infection were low and no lesions were attributed to the parasites. Seven species appear to be specialists in ospreys, 2 species generalists in raptors, and the remainder generalists in other orders of fish-eating birds. Pandiontrema rjikovi, Diasiella diasi, and Contracaecum pandioni are reported for the first time from North America.

  8. Clinical characteristics of Takotsubo cardiomyopathy in North America

    OpenAIRE

    Saeed Ahmed; Patompong Ungprasert; Supawat Ratanapo; Tanveer Hussain; Riesenfeld, Erik P.

    2013-01-01

    Background: Takotsubo cardiomyopathy (TC) or transient left ventricular apical ballooning syndrome is an acute cardiac syndrome characterized by transient wall motion abnormalities extending beyond a single epicardial vessel in the absence of significant obstructive coronary artery disease. Aim: This study was to describe the clinical characteristics of TC in North America. Materials and Methods: We identified 10 patients who met the Mayo Clinic criteria for TC using our Electronic Medical Re...

  9. Best strategy through Marketing Alliances for Switzerland Tourism North America

    OpenAIRE

    Bourquin, Charlotte; Holleran, James

    2014-01-01

    Having partnerships with Marketing Alliances has been proved to be an effective way for Switzerland Tourism North America to push the Destination promotion and sales as well as increase the awareness of Switzerland with the network. The two existing partnerships are with Virtuoso and Signature Travel Network, both luxury/leisure focused companies. Particularly successful results have been observed with Virtuoso. The process of choosing the right partnership has to be carefully defined ...

  10. US of tissue banking and transplantation in North America

    International Nuclear Information System (INIS)

    Tissue banking in North America began as surgical bone banking in individual hospitals and progressed to recovery of cadaveric tissues, initially by the United States Navy Tissue Bank and more recently to regional tissue banks throughout North America. The American Association of Tissue Banks was established in 1976 to develop standards for tissue banking and the eventual inspection and accreditation of tissue banks. The gathering of statistics of tissue banking practices was first undertaken in 1992, from accredited tissue banks. The most recent statistics were compiled in 1997 and will be reported at this conference.There are currently 63 accredited tissue banks in North America, 60 in the United States and three in Canada. Overall, tissue donation has increased by 48% during this 5 year reporting time. During the same period, the number of living surgical bone donors has decreased from nearly 3,000 to less than 500. This impact is largely due to the new regulations that have been implemented by the Food and Drug Administration (FDA). There were over 340,000 bone grafts distributed in 1996, an increase of 20% over 1992, 33% were not sterilized, 21% were sterilized using irradiation, and 45% were demineralized. Only 1% were processed using ethylene oxide as a sterilant, a decrease from 15% in 1992. The primary mode of preservation and storage is freeze-drying with 90% of the tissues falling into this category and the rest being frozen. The second largest number of grafts distributed were skin grafts. Total tissue grafts distributed including cornea was 445,417. In January 1998, the FDA Final Rule regarding regulation of tissue banking became effective. The elements of that Final Rule and new tissue banking rules the FDA has proposed will be discussed along with regulations recently published by the Health and Human Services Department relative to organ and tissue donor referrals. Tissue Banking in North America continues to evolve and has become more and more

  11. Oral Rabies Vaccination in North America: Opportunities, Complexities, and Challenges

    OpenAIRE

    Dennis Slate; Timothy P Algeo; Kathleen M Nelson; Chipman, Richard B.; Dennis Donovan; Blanton, Jesse D.; Michael Niezgoda; Rupprecht, Charles E.

    2009-01-01

    Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV). Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, a...

  12. Recent Rates of Forest Harvest and Conversion in North America

    Science.gov (United States)

    Masek, Jeffrey G.; Cohen, Warren B.; Leckie, Donald; Wulder, Michael A.; Vargas, Rodrigo; de Jong, Ben; Healey, Sean; Law, Beverly; Birdsey, Richard; Houghton, R. A.; Mildrexler, David; Goward, Samuel; Smith, W. Brad

    2011-01-01

    Incorporating ecological disturbance into biogeochemical models is critical for estimating current and future carbon stocks and fluxes. In particular, anthropogenic disturbances, such as forest conversion and wood harvest, strongly affect forest carbon dynamics within North America. This paper summarizes recent (2000.2008) rates of extraction, including both conversion and harvest, derived from national forest inventories for North America (the United States, Canada, and Mexico). During the 2000s, 6.1 million ha/yr were affected by harvest, another 1.0 million ha/yr were converted to other land uses through gross deforestation, and 0.4 million ha/yr were degraded. Thus about 1.0% of North America fs forests experienced some form of anthropogenic disturbance each year. However, due to harvest recovery, afforestation, and reforestation, the total forest area on the continent has been roughly stable during the decade. On average, about 110 m3 of roundwood volume was extracted per hectare harvested across the continent. Patterns of extraction vary among the three countries, with U.S. and Canadian activity dominated by partial and clear ]cut harvest, respectively, and activity in Mexico dominated by conversion (deforestation) for agriculture. Temporal trends in harvest and clearing may be affected by economic variables, technology, and forest policy decisions. While overall rates of extraction appear fairly stable in all three countries since the 1980s, harvest within the United States has shifted toward the southern United States and away from the Pacific Northwest.

  13. Recent rates of forest harvest and conversion in North America

    Science.gov (United States)

    Masek, Jeffrey G.; Cohen, Warren B.; Leckie, Donald; Wulder, Michael A.; Vargas, Rodrigo; de Jong, Ben; Healey, Sean; Law, Beverly; Birdsey, Richard; Houghton, R. A.; Mildrexler, David; Goward, Samuel; Smith, W. Brad

    2011-12-01

    Incorporating ecological disturbance into biogeochemical models is critical for estimating current and future carbon stocks and fluxes. In particular, anthropogenic disturbances, such as forest conversion and wood harvest, strongly affect forest carbon dynamics within North America. This paper summarizes recent (2000-2008) rates of extraction, including both conversion and harvest, derived from national forest inventories for North America (the United States, Canada, and Mexico). During the 2000s, 6.1 million ha/yr were affected by harvest, another 1.0 million ha/yr were converted to other land uses through gross deforestation, and 0.4 million ha/yr were degraded. Thus about 1.0% of North America's forests experienced some form of anthropogenic disturbance each year. However, due to harvest recovery, afforestation, and reforestation, the total forest area on the continent has been roughly stable during the decade. On average, about 110 m3 of roundwood volume was extracted per hectare harvested across the continent. Patterns of extraction vary among the three countries, with U.S. and Canadian activity dominated by partial and clear-cut harvest, respectively, and activity in Mexico dominated by conversion (deforestation) for agriculture. Temporal trends in harvest and clearing may be affected by economic variables, technology, and forest policy decisions. While overall rates of extraction appear fairly stable in all three countries since the 1980s, harvest within the United States has shifted toward the southern United States and away from the Pacific Northwest.

  14. A revised estimate of Pacific-North America motion and implications for Western North America plate boundary zone tectonics

    Science.gov (United States)

    Demets, Charles; Gordon, Richard G.; Stein, Seth; Argus, Donald F.

    1987-01-01

    Marine magnetic profiles from the Gulf of Californa are studied in order to revise the estimate of Pacific-North America motion. It is found that since 3 Ma spreading has averaged 48 mm/yr, consistent with a new global plate motion model derived without any data. The present data suggest that strike-slip motion on faults west of the San Andreas is less than previously thought, reducing the San Andreas discrepancy with geodetic, seismological, and other geologic observations.

  15. 46 CFR 42.03-15 - The Great Lakes of North America.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false The Great Lakes of North America. 42.03-15 Section 42.03... VOYAGES BY SEA Application § 42.03-15 The Great Lakes of North America. (a) The term “Great Lakes of North America” means those waters of North America which are defined in § 42.05-40, and in the exception...

  16. Uncertainty Quantification for a Climatology of the Frequency and Spatial Distribution of North Atlantic Tropical Cyclone Landfalls

    Science.gov (United States)

    Tolwinski-Ward, S. E.; Stransky, S. M.

    2014-12-01

    We develop a Bayesian hierarchical model for the climatological frequency of Atlantic Basin tropical cyclone (TC) landfalls along the coast of North and Central America. The model is explicitly spatial, with a covariance structure that incorporates the effects of coastline geometry, and is resolved at impacts-relevant, 50-mile coastal increments. The model is based on a negative binomial regression on the phase of the Southern Oscillation, North Atlantic Oscillation, and the Atlantic Multidecadal Oscillation, and also accounts explicitly for the time-dependent uncertainty in the historical data used to fit it. The statistically-inferred climatology is interpreted in terms of current scientific understanding of the mechanisms through which related large-scale climatic variability affects the development and motion of Atlantic tropical cyclones. We also probe the spatial posterior probability distribution to quantify and rank the uncertainty in the climatology of TC landfalls that can be attributed to climatic variability, model parameter uncertainty, uncertainty in the historical landfall positions, a possible undercount bias early in the historical record, and sampling variability from the finite length of the observations. Given more detailed, expert information about uncertainty for each specific storm in the historical dataset, the model could be used to develop a definitive TC landfall climatology. It could also be used in conjunction with spatial information about exposures for risk management applications.

  17. Monitoring the North Atlantic using ocean colour data

    Science.gov (United States)

    Fuentes-Yaco, C.; Caverhill, C.; Maass, H.; Porter, C.; White, GN, III

    2016-04-01

    The Remote Sensing Unit (RSU) at the Bedford Institute of Oceanography (BIO) has been monitoring the North Atlantic using ocean colour products for decades. Optical sensors used include CZCS, POLDER, SeaWiFS, MODIS/Aqua and MERIS. The monitoring area is defined by the Atlantic Zone Monitoring Program (AZMP) but certain products extend into Arctic waters, and all-Canadian waters which include the Pacific coast. RSU provides Level 3 images for various products in several formats and a range of temporal and spatial resolutions. Basic statistics for pre-defined areas of interest are compiled for each product. Climatologies and anomaly maps are also routinely produced, and custom products are delivered by request. RSU is involved in the generation of Level 4 products, such as characterizing the phenology of spring and fall phytoplankton blooms, computing primary production, using ocean colour to aid in EBSA (Ecologically and Biologically Significant Area) definition and developing habitat suitability maps. Upcoming operational products include maps of diatom distribution, biogeochemical province boundaries, and products from sensors such as VIIRS (Visible Infrared Imaging Radiometer Suite), OLCI (Ocean Land Colour Instrument), and PACE (Pre-Aerosol, Clouds and ocean Ecosystem) hyperspectral microsatellite mission.

  18. Valuable biomolecules from nine North Atlantic red macroalgae

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft;

    2016-01-01

    In modern society, novel marine resources are scrutinized pursuing compounds of use in the medical, pharmaceutical, biotech, food or feed industry. Few of the numerous marine macroalgae are currently exploited. In this study, the contents of nutritional compounds from nine common North Atlantic red......, glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception of...... phosphorus, were higher than those described for conventional food. Low sodium/potassium ratios (0.08 - 2.54) suggested a potential for using the ash fraction for sodium salt replacement. The algae constituted rich sources of carbohydrates (40% to 71% of DM) which show their potential for a broader...

  19. Sting jets in intense winter North-Atlantic windstorms

    International Nuclear Information System (INIS)

    Extratropical cyclones dominate autumn and winter weather over western Europe. The strongest cyclones, often termed windstorms, have a large socio-economic impact due to the strong surface winds and associated storm surges in coastal areas. Here we show that sting jets are a common feature of windstorms; up to a third of the 100 most intense North-Atlantic winter windstorms over the last two decades satisfy conditions for sting jets. The sting jet is a mesoscale descending airstream that can cause strong near-surface winds in the dry slot of the cyclone, a region not usually associated with strong winds. Despite their localized transient nature, these sting jets can cause significant damage, a prominent example being the storm that devastated southeast England on 16 October 1987. We present the first regional climatology of windstorms with sting jets. Previously analysed sting-jet cases appear to have been exceptional in their track over northwest Europe rather than in their strength. (letter)

  20. The North Atlantic Oscillation system and plant phenology

    Science.gov (United States)

    Hubálek, Zdenek

    2016-05-01

    The onset of flowering in 78 wild and domesticated terrestrial plant species recorded in South Moravia (Czech Republic) from 1965 to 2014 was correlated with the North Atlantic Oscillation (NAO) index of the preceding winter. Flowering occurred significantly earlier following positive winter NAO phases (causing spring to be warmer than normal in Central Europe) in nearly all early-flowering (March, April) species; high Pearson correlation values were recorded in, e.g., goat willow, spring snowflake, golden bell, cornelian cherry, sweet violet, cherry plum, grape hyacinth, apricot, blackthorn, common dandelion, cherry, southern magnolia, common apple, cuckoo flower, European bird cherry, and cherry laurel. In contrast, the timing of later-flowering plant species (May to July) did not correlate significantly with the winter NAO index. It was found that local temperature is obviously a proximate factor of plant phenology, while the winter NAO is the ultimate factor, affecting temperature and other meteorological phenomena in Central Europe during spring season.

  1. Late Miocene biogeography and paleoclimatology of the central North Atlantic

    Science.gov (United States)

    Poore, R.Z.

    1981-01-01

    Quantitative analyses of planktonic foraminiferal assemblages from Deep Sea Drilling Project (DSDP) Holes 334 and 410 demonstrate that subpolar and subtropical faunal provinces existed in the North Atlantic during the late Miocene. Climatic oscillations are clearly recorded in Hole 410 by variations in abundance of the Neogloboquadrina subpolar assemblage. These climatic oscillations have a period of about 1 m.y. Higher frequency oscillations with a periodicity of one to several hundred thousand years are evident from about 6.5 to 7.5 m.y. and are probably present throughout the entire late Miocene. A revised age of 7.0 m.y. is proposed for the first occurrence of the calcareous nannofossil Amaurolithus primus (the Amaurolithus datum). ?? 1981.

  2. Functional responses of North Atlantic fish eggs to increasing temperature

    DEFF Research Database (Denmark)

    Tsoukali, Stavroula; Visser, Andre; MacKenzie, Brian

    2016-01-01

    Temperature increase associated with global climate change can be expected to directly influence the spawning success of fish species, with implications for abundance and distribution. We conducted a meta-analysis to investigate and compare responses of development time, cumulative degree-days and...... survival of fish eggs from 32 populations of 17 species in the North Atlantic to different temperatures in order to determine potential consequences of global warming for these species. The response of development time exhibited a similar decreasing trend with respect to temperature across species. The...... similar slopes of regression lines relating lntransformed development time and temperature indicate similar sensitivity to temperature changes. Across-species differences were mainly driven by intercept values, indicating up to 8- fold differences in development time at given temperature. There was an...

  3. Marine biogenic source of atmospheric organic nitrogen in the subtropical North Atlantic.

    Science.gov (United States)

    Altieri, Katye E; Fawcett, Sarah E; Peters, Andrew J; Sigman, Daniel M; Hastings, Meredith G

    2016-01-26

    Global models estimate that the anthropogenic component of atmospheric nitrogen (N) deposition to the ocean accounts for up to a third of the ocean's external N supply and 10% of anthropogenic CO2 uptake. However, there are few observational constraints from the marine atmospheric environment to validate these findings. Due to the paucity of atmospheric organic N data, the largest uncertainties related to atmospheric N deposition are the sources and cycling of organic N, which is 20-80% of total N deposition. We studied the concentration and chemical composition of rainwater and aerosol organic N collected on the island of Bermuda in the western North Atlantic Ocean over 18 mo. Here, we show that the water-soluble organic N concentration ([WSON]) in marine aerosol is strongly correlated with surface ocean primary productivity and wind speed, suggesting a marine biogenic source for aerosol WSON. The chemical composition of high-[WSON] aerosols also indicates a primary marine source. We find that the WSON in marine rain is compositionally different from that in concurrently collected aerosols, suggesting that in-cloud scavenging (as opposed to below-cloud "washout") is the main contributor to rain WSON. We conclude that anthropogenic activity is not a significant source of organic N to the marine atmosphere over the North Atlantic, despite downwind transport from large pollution sources in North America. This, in conjunction with previous work on ammonium and nitrate, leads to the conclusion that only 27% of total N deposition to the global ocean is anthropogenic, in contrast to the 80% estimated previously. PMID:26739561

  4. The alkenone temperature signal in western North Atlantic surface waters

    Science.gov (United States)

    Conte, M. H.; Weber, J. C.; King, L. L.; Wakeham, S. G.

    2001-12-01

    Haptophyte algae-derived long-chain C 37-C 39 alkenones and alkyl alkenoates were analyzed in euphotic zone particulate matter collected over a 7 yr period at the Oceanic Flux Program/Bermuda Atlantic Time Series (OFP/BATS) site in the western Sargasso Sea. Surface water temperatures at the site range annually from 19 to 29°C. Alkenone concentrations ranged from 100 ng L -1 following the passage of storms. Highest seasonal concentrations occurred during the late winter and spring. Under stratified conditions, alkenone concentrations in the surface mixed layer (0-20 m) were generally 2 to 4 times higher than in the deep fluorescent maximum (75-110 m), consistent with Emiliania huxleyi concentration profiles (Haidar and Thierstein, 2001) and indicated that alkenone production primarily occurs within the upper euphotic zone in this region. Alkenone compound distributions and the temperature calibrations of C 37 and C 38 methyl and ethyl alkenone unsaturation (U 37K', U 38MeK, and U 38EtK, respectively) were remarkably similar to that observed in an E. huxleyi strain previously isolated from the same area (Conte et al., 1998), providing strong evidence that E. huxleyi is the predominant alkenone synthesizer and that characteristics exhibited by randomly isolated clones in culture are, in many cases, consistent with those of populations in the region of origin. The Bermuda calibration of U 37K' vs. water temperature (U 37K' = -1.9835 + 0.2004T - 0.0034T 2, r 2 = 0.95, n = 91) is nonlinear and falls along the same trendline as euphotic zone particulates from warm (> 15°C) waters of the eastern North Atlantic (Conte and Eglinton, 1993) and Mediterranean (Ternois et al., 1997). The combined North Atlantic temperature calibration (U 37K' = - 1.1365 + 0.1257T - 0.0018T 2, r 2 = 0.963, n = 134) differs significantly from published coretop sediment calibrations (Rosell-Melé et al., 1995; Müller et al., 1998) based on sea surface temperature maps (Levitus and Boyer, 1994

  5. Terrane Stations: intra-oceanic subduction assembled western North America

    Science.gov (United States)

    Sigloch, K.; Mihalynuk, M. G.

    2012-12-01

    The western quarter of North America consists of accreted terranes, crustal blocks that were added to the margin in a series of collisions over the past 200 million years - but why? The most widely accepted explanation posits a scenario analogous to Andean subduction, with these terranes conveyed to the continental margin while the oceanic Farallon plate subducted under it. Yet purely Andean-style subduction under North America is questionable as a terrane delivery mechanism, since no comparable accretion sequence took place along the South American margin, and since North American terranes are of very varied provenance. We consider this geological question directly related to a geodynamical one: Why has it been so difficult to reconcile - even on the largest scale - the geometries and locations of slabs in the lower-mantle, as imaged by seismic tomography, with Cretaceous plate reconstructions of the North American west coast (unless anomalous mantle rheology or ad hoc shifts of absolute reference frame are invoked)? This problem was recognized soon after the discovery of the massive, lower-mantle "Farallon slabs" by Grand (1994), but has recently been aggravated by the discovery of additional, more westerly deep slabs (Sigloch et al. 2008), thanks to USArray. Not all of these slabs can be Farallon, unless very non-vertical and/or uneven slab sinking behavior is allowed for. As a joint solution, we offer a radical reinterpretation of paleogeography and test it quantitatively: The seas west of Cretaceous North America must have resembled today's western Pacific. The Farallon and two more plates subducted into the intra-oceanic trenches of a vast archipelago in the eastern Panthalassa (proto-Pacific) ocean, both from the east and the west. The trenches remained stationary throughout much of Jurassic and Cretaceous times, depositing the massive, near-vertical slab walls imaged in the lower mantle today. On their overriding plates, island arcs and subduction complexes

  6. Heat wave frequency variability over North America: Two distinct leading modes

    Science.gov (United States)

    Wu, Zhiwei; Lin, Hai; Li, Jianping; Jiang, Zhihong; Ma, Tingting

    2012-01-01

    Seasonal prediction of heat wave variability is a scientific challenge and of practical importance. This study investigates the heat wave frequency (HWF) variability over North America (NA) during the past 53 summers (1958-2010). It is found that the NA HWF is dominated by two distinct modes: the interdecadal (ID) mode and the interannual (IA) mode. The ID mode primarily depicts a HWF increasing pattern over most of the NA continent except some western coastal areas. The IA mode resembles a tripole HWF anomaly pattern with three centers over the northwestern, central, and southern NA. The two leading modes have different dynamic structures and predictability sources. The ID mode is closely associated with the prior spring sea surface temperature anomaly (SSTA) in the tropical Atlantic and tropical western Pacific that can persist throughout the summer, whereas the IA mode is linked to the development of El Niño-Southern Oscillation. A simplified general circulation model is utilized to examine the possible physical mechanism. For the ID mode the tropical Atlantic SSTA can induce a Gill-type response which extends to NA, while the northwestern Pacific SSTA excites a Rossby wave train propagating eastward toward NA. These two flow patterns jointly contribute to the formation of the large-scale circulation anomalies associated with the ID mode. For the IA mode the corresponding circulation anomalies are basically similar to a Pacific-North America pattern. The subsidence associated with high-pressure anomalies warms and dries the boundary layer, inhibiting cloud formation. The resulting surface radiative heating further warms the surface. For the low-pressure anomalies the situation is just opposite. Through such processes these SSTAs can exert profound influences on the HWF variability over NA.

  7. Causes of decadal climate variability over the North Pacific and North America

    International Nuclear Information System (INIS)

    The cause of decadal climate variability over the North Pacific and North America is investigated by analyzing data from a multi-decadal integration with a state of the art coupled ocean-atmosphere model and observations. About one third of the low-frequency climate variability in the region of interest can be attributed to a cycle involving unstable air-sea interactions between the subtropical gyre circulation in the North Pacific and the Aleutian low pressure system. The existence of this cycle provides a basis for long-range climate forecasting over the western United States at decadal time scales. (orig.)

  8. The observational influence of the North Atlantic SST tripole on the early spring atmospheric circulation

    Science.gov (United States)

    Han, Zhe; Luo, Feifei; Wan, Jianghua

    2016-03-01

    This study investigated the forcing of the North Atlantic sea surface temperature (SST) tripole on the North Atlantic Oscillation (NAO)-like circulation in early spring (February-April) in observations. Corresponding to an SST tripole forcing in early spring, the atmospheric circulation is very weak and insignificant. However, further analyses indicate that the observational effect of the SST anomalies on the NAO-like circulation is disturbed by the concomitant sea ice anomalies. With the linear effects of sea ice anomalies removed, there is an equivalent barotropic NAO-like circulation in early spring related to a North Atlantic SST tripole.

  9. Latitudinal disparity in the reproductive cycle of sharpnose shark, Rhizoprionodon lalandii (Elasmobranchii: Carcharhinidae, in Atlantic waters off South America

    Directory of Open Access Journals (Sweden)

    Morgana M. Macedo

    2012-10-01

    Full Text Available Geographical variation in biophysical conditions may strongly influence the life history characteristics of widely distributed species, such as the Brazilian sharpnose shark, Rhizoprionodon lalandii (Müller & Henle, 1839. Here, we use original and secondary data of reproductive traits of R. lalandii to identify population differences among northern/northeastern and southern Atlantic waters of South America. In the southeast region, birth occurs between December and March, and the young become frequent along the coast between April and September. Mating occurs mainly between March and June, when females with bite marks are common. Females in early pregnancy occur between March and September. The reproductive cycle of R. lalandii in the northern/northeastern region was approximately six months ahead of the cycle described for the southeastern region. These results support the hypothesis that environmental conditions in the North-Northeast and Southeast generate differences in life history traits, resulting in at least two distinct populations along the Brazilian coast.

  10. 77 FR 62535 - Hydro Aluminum North America, Inc., Midwest Region, Including On-Site Leased Workers From...

    Science.gov (United States)

    2012-10-15

    ... Employment and Training Administration Hydro Aluminum North America, Inc., Midwest Region, Including On- Site Leased Workers From Employment Group, Aerotek, and Manpower, Kalamazoo, Michigan; Hydro Aluminum North... and former workers of Hydro Aluminum North America, Inc., Kalamazoo, Michigan. The subject...

  11. Catalogue of Geadephaga (Coleoptera: Adephaga of America, north of Mexico

    Directory of Open Access Journals (Sweden)

    Yves Bousquet

    2012-11-01

    Full Text Available All scientific names of Trachypachidae, Rhysodidae, and Carabidae (including cicindelines recorded from America north of Mexico are catalogued. Available species-group names are listed in their original combinations with the author(s, year of publication, page citation, type locality, location of the name-bearing type, and etymology for many patronymic names. In addition, the reference in which a given species-group name is first synonymized is recorded for invalid taxa. Genus-group names are listed with the author(s, year of publication, page citation, type species with way of fixation, and etymology for most. The reference in which a given genus-group name is first synonymized is recorded for many invalid taxa. Family-group names are listed with the author(s, year of publication, page citation, and type genus. The geographical distribution of all species-group taxa is briefly summarized and their state and province records are indicated.One new genus-group taxon, Randallius new subgenus (type species: Chlaenius purpuricollis Randall, 1838, one new replacement name, Pterostichus amadeus new name for Pterostichus vexatus Bousquet, 1985, and three changes in precedence, Ellipsoptera rubicunda (Harris, 1911 for Ellipsoptera marutha (Dow, 1911, Badister micans LeConte, 1844 for Badister ocularis Casey, 1920, and Agonum deplanatum Ménétriés, 1843 for Agonum fallianum (Leng, 1919, are proposed. Five new genus-group synonymies and 65 new species-group synonymies, one new species-group status, and 12 new combinations (see Appendix 5 are established.The work also includes a discussion of the notable private North American carabid collections, a synopsis of all extant world geadephagan tribes and subfamilies, a brief faunistic assessment of the fauna, a list of valid species-group taxa, a list of North American fossil Geadephaga (Appendix 1, a list of North American Geadephaga larvae described or illustrated (Appendix 2, a list of Geadephaga species

  12. Wave Extremes in the North East Atlantic from Ensemble Forecasts

    CERN Document Server

    Breivik, Øyvind; Bidlot, Jean-Raymond; Carrasco, Ana; Saetra, Øyvind; 10.1175/JCLI-D-12-00738.1

    2013-01-01

    A method for estimating return values from ensembles of forecasts at advanced lead times is presented. Return values of significant wave height in the North-East Atlantic, the Norwegian Sea and the North Sea are computed from archived +240-h forecasts of the ECMWF ensemble prediction system (EPS) from 1999 to 2009. We make three assumptions: First, each forecast is representative of a six-hour interval and collectively the data set is then comparable to a time period of 226 years. Second, the model climate matches the observed distribution, which we confirm by comparing with buoy data. Third, the ensemble members are sufficiently uncorrelated to be considered independent realizations of the model climate. We find anomaly correlations of 0.20, but peak events (>P97) are entirely uncorrelated. By comparing return values from individual members with return values of subsamples of the data set we also find that the estimates follow the same distribution and appear unaffected by correlations in the ensemble. The a...

  13. Collapse of the western North America climate dipole during the MCA and LIA

    Science.gov (United States)

    Asmerom, Y.; Polyak, V. J.; Rasmussen, J.; Burns, S. J.; Lachniet, M. S.

    2011-12-01

    Understanding of the teleconnections between regional climate regimes and the time-scale of the stability of these teleconnections is crucial for building predictive models of climate change. Using annually-resolved speleothem physical (band thickness, hiatus and mineralogy) and oxygen and carbon isotopic effective moisture proxy data, we show climate variability in the southwestern United States (SW) during the critical Medieval Climate Anomaly and Little Ice Age (LIA) intervals. Although the MCA overall was not markedly drier than the wet latter half of the LIA, it was punctuated by multiple megadroughts. The driest interval was the early LIA, during which we identify an extended multi-century drought, which we will refer to as a Super Drought (SD), occurring during the early LIA ca. AD 1350 to AD 1650. There is a well-established dipole response to Pacific Decadal Oscillation (PDO) and El Nino-Southern Oscillation (ENSO) variability between the SW and northwestern United States (NW), and the SW and the Asian monsoon during the modern and overall Holocene climate regime. Our data indicate that this climate dipole apparently collapsed during the MCA-LIA, extending back to about 300 AD, such that pluvial and drought intervals in the SW and NW, and SW and Asian monsoon occur contemporaneously over this period. The modern positive relationship between moisture and the PDO observed in the SW is also reversed. During this interval the PDO is negatively correlated with SW moisture amount. In addition, the strong solar control of Holocene climate observed previously in western North America and the Asian monsoon is weakened during parts of this interval, such that solar maxima and minima do not correlate coherently with precipitation variability both in North America and the Asian monsoon. The MCA-early LIA period in which the megadroughts dominate occurs within the prominently positive phase of the North Atlantic Oscillation (NAO). One potential mechanism of propagating

  14. 77 FR 16538 - Endangered and Threatened Species; Initiation of 5-Year Review for the North Atlantic Right Whale...

    Science.gov (United States)

    2012-03-21

    ...; Initiation of 5-Year Review for the North Atlantic Right Whale and the North Pacific Right Whale AGENCY... review of North Atlantic right whale (Eubalaena glacialis) and North Pacific right whale (Eubalaena... of any such information on these whales that has become available since the last status review...

  15. Phylogeography of infectious haematopoietic necrosis virus in North America

    DEFF Research Database (Denmark)

    Kurath, G.; Garver, K.A.; Troyer, R.M.;

    2003-01-01

    Infectious hematopoietic necrosis virus (IHNV) is a rhabdoviral pathogen that infects wild and cultured salmonid fish throughout the Pacific Northwest of North America. IHNV causes severe epidemics in young fish and can cause disease or occur asymptomatically in adults. In a broad survey of 323...... IHNV field isolates, sequence analysis of a 303 nucleotide variable region within the glycoprotein gene revealed a maximum nucleotide diversity of 8(.)6%, indicating low genetic diversity overall for this virus. Phylogenetic analysis revealed three major virus genogroups, designated U, M and L, which...

  16. Borderlands : Comparing Border Security in North America and Europe

    OpenAIRE

    Brunet-Jailly, Emmanuel

    2007-01-01

    Border security has been high on public-policy agendas in Europe and North America since the September 11, 2001 attacks on the World Trade Centre in New York City and on the headquarters of the American military in Washington DC. Governments are now confronted with managing secure borders, a policy objective that in this era of increased free trade and globalization must compete with intense cross-border flows of people and goods. Border-security policies must enable security personnel to ide...

  17. A revision of the Alpova diplophloeus complex in North America.

    Science.gov (United States)

    Hayward, Jeremy; Tourtellot, Samuel G; Horton, Thomas R

    2014-01-01

    Alpova diplophloeus (Boletales, Paxillaceae) is the only currently recognized Alpova in North America with a brownish peridium, large gleba chambers and which forms ectomycorrhizas with Alnus. However, A. diplophloeus as currently circumscribed is a polyphyletic species, with at least three distinct genetic entities. Using a combination of molecular and morphological characters, we examined the type collections of A. diplophloeus, as well as species synonymized with it, including A. cinnamomeus and Rhizopogon parvisporus. We also examined several other collections of A. diplophloeus complex basidiomata. We describe A. diplophloeus sensu stricto; we also resurrect A. cinnamomeus, synonymized with R. parvisporus and describe a new species, A. concolor, from the complex. PMID:24891419

  18. Renewable energy in North America: Moving toward a richer mix

    Energy Technology Data Exchange (ETDEWEB)

    Cobey, Cathy

    2010-09-15

    A follow-up to our January study with Economist Intelligence Unit, Renewable energy in North America. The update will further our call to action for a concerted group effort by energy suppliers, corporate consumers and government. 1. Introduction - State of the industry, progress made to replace carbon-based fossil fuels with alternative energy - Barriers - Pressure from public and government 2. Recent progress - Examine existing government incentive programs - International commitments - Examine the role of energy suppliers, corporate consumers and government 3. Call to Action - Creating an environment that encourages both supply and demand of renewable energy.

  19. PAGES-Powell North America 2k database

    Science.gov (United States)

    McKay, N.

    2014-12-01

    Syntheses of paleoclimate data in North America are essential for understanding long-term spatiotemporal variability in climate and for properly assessing risk on decadal and longer timescales. Existing reconstructions of the past 2,000 years rely almost exclusively on tree-ring records, which can underestimate low-frequency variability and rarely extend beyond the last millennium. Meanwhile, many records from the full spectrum of paleoclimate archives are available and hold the potential of enhancing our understanding of past climate across North America over the past 2000 years. The second phase of the Past Global Changes (PAGES) North America 2k project began in 2014, with a primary goal of assembling these disparate paleoclimate records into a unified database. This effort is currently supported by the USGS Powell Center together with PAGES. Its success requires grassroots support from the community of researchers developing and interpreting paleoclimatic evidence relevant to the past 2000 years. Most likely, fewer than half of the published records appropriate for this database are publicly archived, and far fewer include the data needed to quantify geochronologic uncertainty, or to concisely describe how best to interpret the data in context of a large-scale paleoclimatic synthesis. The current version of the database includes records that (1) have been published in a peer-reviewed journal (including evidence of the record's relationship to climate), (2) cover a substantial portion of the past 2000 yr (>300 yr for annual records, >500 yr for lower frequency records) at relatively high resolution (<50 yr/observation), and (3) have reasonably small and quantifiable age uncertainty. Presently, the database includes records from boreholes, ice cores, lake and marine sediments, speleothems, and tree rings. This poster presentation will display the site locations and basic metadata of the records currently in the database. We invite anyone with interest in

  20. Coupling of the distribution of silicon isotopes to the meridional overturning circulation of the North Atlantic Ocean

    Science.gov (United States)

    Brzezinski, Mark A.; Jones, Janice L.

    2015-06-01

    The distribution of silicon isotopes within silicic acid, δ30Si(OH)4, was examined along a section in the North Atlantic from the Cape Verde Islands off Africa to Cape Cod, Massachusetts in North America. Surface water displayed elevated δ30Si(OH)4 associated with biological fractionation of Si during silica production. Below 300 m variations in δ30Si(OH)4 were closely tied to the distribution of water masses as diagnosed through optimum multiparameter analysis, confirming a tight relationship between δ30Si(OH)4 and the meridional overturning circulation in the Atlantic. A linear relationship between δ30Si(OH)4 and the inverse of silicic acid concentration supported control of Si isotope distribution by conservative mixing of end member water masses of different isotopic composition in the Atlantic. There was a suggestion of a weak local minimum in δ30Si(OH)4 in deep waters above the Trans-Atlantic Geotraverse hydrothermal zone on the mid-Atlantic Ridge consistent with the light δ30Si(OH)4 of hydrothermal waters. The lightest δ30Si(OH)4 values were observed in the deep western and deep eastern basins where Antarctic Bottom Water (AABW) dominated. The heaviest values in subsurface waters occurred in North Atlantic Deep Water due to strong ventilation and the contribution of heavy northern source waters that are influenced by the Arctic Ocean. The concept of a silicon isotope bipole is introduced to explain how the isotopic differences between the northern and southern end-member water masses arise, and how they influence Si isotope distributions. Northern end-member water masses are heavy due to the influence of the Arctic Ocean. Bottom topography prevents light deep waters from entering the Arctic and the further removal of light isotopes through local biological productivity results in extremely heavy δ30Si(OH)4 within the Arctic. Light AABW dominates the southern end member. The Southern Ocean silicic acid trap distills heavier isotopes of Si out of the

  1. Bat white-nose syndrome in North America

    Science.gov (United States)

    Blehert, David S.; Lorch, Jeffrey M.; Ballmann, Anne E.; Cryan, Paul M.; Meteyer, Carol U.

    2011-01-01

    * The newly described fungus, Geomyces destructans, causes an invasive skin infection in bats and is the likely agent of white-nose syndrome (WNS). * With immune system functions and body temperatures reduced during hibernation, bats may be unusually susceptible to a pathogenic fungus such as G. destructans. * WNS was first observed in a popular show cave near Albany, New York, leading some investigators to suspect that a visitor inadvertently introduced G. destructans at this site, triggering a wider WNS outbreak in North America. * Biologists trying to manage WNS within North American bat populations face major challenges, including the variety of susceptible host species, incredible dispersal capabilities of bats, difficulties in treating such populations, and persistence of the pathogen in their vulnerable underground habitats.

  2. Rapid Middle Eocene temperature change in western North America

    Science.gov (United States)

    Methner, Katharina; Mulch, Andreas; Fiebig, Jens; Wacker, Ulrike; Gerdes, Axel; Graham, Stephan A.; Chamberlain, C. Page

    2016-09-01

    Eocene hyperthermals are among the most enigmatic phenomena of Cenozoic climate dynamics. These hyperthermals represent temperature extremes superimposed on an already warm Eocene climate and dramatically affected the marine and terrestrial biosphere, yet our knowledge of temperature and rainfall in continental interiors is still rather limited. We present stable isotope (δ18O) and clumped isotope temperature (Δ47) records from a middle Eocene (41 to 40 Ma) high-elevation mammal fossil locality in the North American continental interior (Montana, USA). Δ47 paleotemperatures of soil carbonates delineate a rapid +9/-11 °C temperature excursion in the paleosol record. Δ47 temperatures progressively increase from 23 °C ± 3 °C to peak temperatures of 32 °C ± 3 °C and subsequently drop by 11 °C. This hyperthermal event in the middle Eocene is accompanied by low δ18O values and reduced pedogenic carbonate concentrations in paleosols. Based on laser ablation U/Pb geochronology of paleosol carbonates in combination with magnetostratigraphy, biostratigraphy, stable isotope, and Δ47 evidence, we suggest that this pronounced warming event reflects the Middle Eocene Climatic Optimum (MECO) in western North America. The terrestrial expression of northern hemisphere MECO in western North America appears to be characterized by warmer and wetter (sub-humid) conditions, compared to the post-MECO phase. Large and rapid shifts in δ18O values of precipitation and pedogenic CaCO3 contents parallel temperature changes, indicating the profound impact of the MECO on atmospheric circulation and rainfall patterns in the western North American continental interior during this transient warming event.

  3. Shared identity and reconciliation: can a future security framework in Northeast Asia draw from experiences of the North Atlantic security cooperation?

    OpenAIRE

    Langenbach, Andreas

    2013-01-01

    Approved for public release; distribution is unlimited In the wake of the deteriorating relations between the former Allies of the Second World War, several European countries, the United States of America, and Canada came together to provide for their security and in 1949 formed a unique security alliance, the North Atlantic Treaty Organization. In addition to its collective defense function, the creators of NATO also paid attention to community building among the alliance members. After ...

  4. Spatio-temporal Interplay of RWTs and Cyclones in the North Atlantic

    Science.gov (United States)

    Schuster, M.; Ulbrich, U.

    2014-12-01

    . The Two-Way-Nested region, thus the CCLM domain, covers Central America and the North Atlantic (CANA) and therefore includes the Gulf stream region, whose prevalent strong meridional SST gradients favor the development of perturbations which then propagate downstream, commonly develop into extra-tropical cyclones and strike Europe.

  5. Abrupt changes in the southern extent of North Atlantic Deep Water during Dansgaard-Oeschger events

    Science.gov (United States)

    Gottschalk, Julia; Skinner, Luke C.; Misra, Sambuddha; Waelbroeck, Claire; Menviel, Laurie; Timmermann, Axel

    2015-12-01

    The glacial climate system transitioned rapidly between cold (stadial) and warm (interstadial) conditions in the Northern Hemisphere. This variability, referred to as Dansgaard-Oeschger variability, is widely believed to arise from perturbations of the Atlantic Meridional Overturning Circulation. Evidence for such changes during the longer Heinrich stadials has been identified, but direct evidence for overturning circulation changes during Dansgaard-Oeschger events has proven elusive. Here we reconstruct bottom water [CO32-] variability from B/Ca ratios of benthic foraminifera and indicators of sedimentary dissolution, and use these reconstructions to infer the flow of northern-sourced deep water to the deep central sub-Antarctic Atlantic Ocean. We find that nearly every Dansgaard-Oeschger interstadial is accompanied by a rapid incursion of North Atlantic Deep Water into the deep South Atlantic. Based on these results and transient climate model simulations, we conclude that North Atlantic stadial-interstadial climate variability was associated with significant Atlantic overturning circulation changes that were rapidly transmitted across the Atlantic. However, by demonstrating the persistent role of Atlantic overturning circulation changes in past abrupt climate variability, our reconstructions of carbonate chemistry further indicate that the carbon cycle response to abrupt climate change was not a simple function of North Atlantic overturning.

  6. Climate Prediction Center (CPC) Monthly North Atlantic Oscillation (NAO) teleconnection index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the North Atlantic Oscillation (NAO) teleconnection pattern. The data spans the period 1950 to present. The index is derived from a...

  7. Historical North Atlantic Tropical Cyclone Tracks, 1851-2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This Historical North Atlantic Tropical Cyclone Tracks file contains the six-hourly (0000, 0600, 1200, 1800 UTC) center locations and intensities for all northern...

  8. Monitoring and Mitigation Alternatives for Protection of North Atlantic Right Whales during Offshore Wind Farm Installation

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Halvorsen, Michele B.; Matzner, Shari; Copping, Andrea E.; Stavole, Jessica

    2012-09-01

    Progress report on defining and determining monitoring and mitigation measures for protecting North Atlantic Right Whales from the effects of pile driving and other activities associated with installation of offshore wind farms.

  9. An extreme event of sea-level rise along the Northeast Coast of North America in 2009-2010.

    Science.gov (United States)

    Goddard, Paul B; Yin, Jianjun; Griffies, Stephen M; Zhang, Shaoqing

    2015-01-01

    The coastal sea levels along the Northeast Coast of North America show significant year-to-year fluctuations in a general upward trend. The analysis of long-term tide gauge records identified an extreme sea-level rise (SLR) event during 2009-10. Within this 2-year period, the coastal sea level north of New York City jumped by 128 mm. This magnitude of interannual SLR is unprecedented (a 1-in-850 year event) during the entire history of the tide gauge records. Here we show that this extreme SLR event is a combined effect of two factors: an observed 30% downturn of the Atlantic meridional overturning circulation during 2009-10, and a significant negative North Atlantic Oscillation index. The extreme nature of the 2009-10 SLR event suggests that such a significant downturn of the Atlantic overturning circulation is very unusual. During the twenty-first century, climate models project an increase in magnitude and frequency of extreme interannual SLR events along this densely populated coast. PMID:25710720

  10. AMO-like variations of holocene sea surface temperatures in the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    S. Feng

    2009-12-01

    Full Text Available Instrumental records of the North Atlantic sea surface temperatures (SST show a significant 60–80 year cycle, referred to as the Atlantic Multidecadal Oscillation (AMO. During AMO warm (cold phases, SST over the entire North Atlantic Ocean is dominated by basin-wide positive (negative anomalies. We analyzed SST variations in the North Atlantic Ocean for the last 10 ka. The long-term and centennial variations of Holocene SST in the North Atlantic demonstrate a basin-wide mode that clearly resembles the AMO signal recorded during the recent instrumental period. The long-term changes of Holocene SST were controlled by the solar insolation related to the orbital variations, and the centennial variations were closely coupled with the intensity of the thermohaline circulation. The spatial extent in the Atlantic realm of temperature anomalies around two specific time intervals, 8.2 ka and during the medieval warm period, also resemble the observed temperature anomalies associated with the AMO. These results demonstrate that the modern AMO, and centennial and longer time scale SST variations during the Holocene share a similar spatial extent in the North Atlantic, and presumably as well physical processes associated with their existence and their far-field teleconnection effects.

  11. Drought-induced vegetation stress in southwestern North America

    International Nuclear Information System (INIS)

    Trends towards earlier greenup and increased average greenness have been widely reported in both humid and dry ecosystems. By analyzing NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data from 1982 to 2007, we report complex trends in both the growing season amplitude and seasonally integrated vegetation greenness in southwestern North America and further highlight regions consistently experiencing drought stress. In particular, greenness measurements from 1982 to 2007 show an increasing trend in grasslands but a decreasing trend in shrublands. However, vegetation greenness in this period has experienced a strong cycle, increasing from 1982 to 1993 but decreasing from 1993 to 2007. The significant decrease during the last decade has reduced vegetation greenness by 6% in shrublands and 13% in grasslands (16% and 21%, respectively, in the severe drought years). The greenness cycle correlates to both annual precipitation and dry season length derived from NOAA North America Regional Reanalysis data. If drought events continue as predicted by climate models, they will exacerbate ecosystem degradation and reduce carbon uptake.

  12. 2014 outbreak of enterovirus D68 in North America.

    Science.gov (United States)

    Messacar, Kevin; Abzug, Mark J; Dominguez, Samuel R

    2016-05-01

    Enterovirus D68 (EV-D68) is an emerging picornavirus which causes severe respiratory disease, predominantly in children. In 2014, the largest and most widespread outbreak of EV-D68 described to date was reported in North America. Hospitals throughout the United States and Canada reported surges in patient volumes and resource utilization from August to October, 2014. In the US a total of 1,153 infections were confirmed in 49 states, although this is an underestimate of the likely millions of cases that occurred but were not tested. EV-D68 was detected in 14 patients who died; the role of the virus in these deaths is unknown. A possible association between EV-D68 and cases of acute flaccid paralysis with spinal cord gray matter lesions, known as acute flaccid myelitis, was observed during the outbreak and is under investigation. The 2014 outbreak of EV-D68 in North America demonstrates the public health importance of this emerging pathogen. J. Med. Virol. 88:739-745, 2016. © 2015 Wiley Periodicals, Inc. PMID:26489019

  13. Mental Health Problems in Primary Care: Progress in North America

    Directory of Open Access Journals (Sweden)

    Kathryn M. Magruder

    2007-03-01

    Full Text Available Background and Objectives: Research in the last decade has acknowledged that primary care plays a pivotal role in the delivery of mental health services. The aim of this paper is to review major accomplishments, emerging trends, and continuing gaps concerning mental health problems in primary care in North America. Methods: Literature from North America was reviewed and synthesized. Results: Major accomplishments include: the development and adoption of a number of clinical guidelines specifically for mental health conditions in primary care, the acceptance of the chronic care model as a framework for treating depression in primary care, and the clear adoption of pharmacologic approaches as the predominant mode for treating depression and anxiety. Emerging trends include: the use of non-physician facilitators as care managers in the treatment of depression in primary care, increasing use of technology in the assessment and treatment of mental health conditions in primary care, and dissemination and implementation of integrated mental health treatment approaches. Lingering issues include: the difficulty in moving beyond problem identification and initiation of treatment to sustaining evidence-based treatments, agreement on a common metric to evaluate outcomes, and the stigma still associated with mental illness. Conclusion: Though there now exists a solid and growing evidence base for the delivery of mental health services in primary care, there are still significant challenges which must be overcome in order to make further advances.

  14. Frequency of marine heatwaves in the North Atlantic and North Pacific since 1950

    Science.gov (United States)

    Scannell, Hillary A.; Pershing, Andrew J.; Alexander, Michael A.; Thomas, Andrew C.; Mills, Katherine E.

    2016-03-01

    Extreme and large-scale warming events in the ocean have been dubbed marine heatwaves, and these have been documented in both the Northern and Southern Hemispheres. This paper examines the intensity, duration, and frequency of positive sea surface temperature anomalies in the North Atlantic and North Pacific Oceans over the period 1950-2014 using an objective definition for marine heatwaves based on their probability of occurrence. Small-area anomalies occur more frequently than large-area anomalies, and this relationship can be characterized by a power law distribution. The relative frequency of large- versus small-area anomalies, represented by the power law slope parameter, is modulated by basin-scale modes of natural climate variability and anthropogenic warming. Findings suggest that the probability of marine heatwaves is a trade-off between size, intensity, and duration and that region specific variability modulates the frequency of these events.

  15. Intensified impact of tropical Atlantic SST on the western North Pacific summer climate under a weakened Atlantic thermohaline circulation

    OpenAIRE

    Chen, Wei; Lee, June-Yi; Lu, Riyu; Dong, Buwen; Ha, Kyung-Ja

    2015-01-01

    The tropical North Atlantic (TNA) sea surface temperature (SST) has been identified as one of regulators on the boreal summer climate over the western North Pacific (WNP), in addition to SSTs in the tropical Pacific and Indian Oceans. The major physical process proposed is that the TNA warming induces a pair of cyclonic circulation anomaly over the eastern Pacific and negative precipitation anomalies over the eastern to central tropical Pacific, which in turn lead to an anticyclonic circulati...

  16. Apocalypse Then: The Evolution of the North Atlantic Economy and the Global Crisis

    OpenAIRE

    Tamim Bayoumi; Trung Bui

    2011-01-01

    The financial crisis that struck the global economy in late 2008 had its origins in excesses in the US housing market. Its reverberations, however, were felt around the world and nowhere more keenly than in Western Europe. While North Atlantic trade links were in relative stasis, the North Atlantic furnished a uniquely close relationship across financial institutions, as a combination of dominant US financial markets, European competition policy, and differences in financial regulation made t...

  17. Pollution from Aircraft Emissions in the North Atlantic Flight Corridor: Overview on the POLINAT Projects

    OpenAIRE

    Schumann, U.; H. Schlager; F. Arnold; J. Ovarlez; Kelder, H.; O. Hov; Hayman, G.; I. S. A. Isaksen; Staehelin, J.; Whitefield, P.D.

    2000-01-01

    The Pollution From Aircraft Emissions in the North Atlantic Flight Corridor (POLINAT) projects were undertaken to investigate the impact of aircraft engine exhaust emissions on the state of the atmosphere in the North Atlantic flight corridor. Changes in the composition of the lower stratosphere and upper troposphere from aircraft emissions are identified from combined measurements and model analyses. Measurements were performed using the Deutsches Zentrum für Luft- und Raumfahrt Falcon resea...

  18. Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

    OpenAIRE

    Chust, Guillem; Castellani, Claudia; Licandro, Priscilla; Ibaibarriaga, Leire; Sagarminaga, Yolanda; Irigoien, Xabier

    2014-01-01

    In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was trigger...

  19. Global Climate network evolves with North Atlantic Oscillation phases: Coupling to Southern Pacific Ocean

    CERN Document Server

    Guez, Oded; Berezin, Yehiel; Wang, Yang; Havlin, Shlomo

    2013-01-01

    We construct a network from climate records of atmospheric temperature at surface level, at different geographical sites in the globe, using reanalysis data from years 1948-2010. We find that the network correlates with the North Atlantic Oscillation (NAO), both locally in the north Atlantic, and through coupling to the southern Pacific Ocean. The existence of tele-connection links between those areas and their stability over time allows us to suggest a possible physical explanation for this phenomenon.

  20. Impact of North Atlantic Current changes on the Nordic Seas and the Arctic Ocean

    OpenAIRE

    Kauker, Frank; Gerdes, Rüdiger; Karcher, Michael; Köberle, Cornelia

    2005-01-01

    The impact of North Atlantic Current (NAC) volume, heat, and salt transport variability onto the NordicSeas and the Arctic Ocean is investigated using numerical hindcast and sensitivity experiments. Theocean-sea ice model reproduces observed propagation pathways and speeds of SST anomalies.Part of the signal reaching the entrance to the Nordic Seas between Iceland and Scotland originatesin the lower latitude North Atlantic. Response experiments with different prescribed conditionsat 50N show ...

  1. The Iceland–Lofotes pressure difference: different states of the North Atlantic low-pressure zone

    OpenAIRE

    Jahnke-Bornemann, Annika; Brümmer, Burghard

    2009-01-01

    The extended North Atlantic low-pressure zone exhibits two pressure minima in the long-term winter mean: the primary one west of Iceland and the secondary one near Norwegian Lofotes Islands. Based on the ERA-40 data set and on wintertime monthly sea level pressure (SLP) anomalies at both places, the states of co- and antivariability are investigated. The covariability represents states of a strongly or weakly developed North Atlantic low-pressure zone. The difference between these two states ...

  2. How the Subpolar gyre strength influences phytoplankton blooms dynamics in the North Atlantic

    OpenAIRE

    Ferreira, Ana Sofia; Payne, Mark; Mackenzie, Brian; Visser, Andre

    2012-01-01

    Changes in the North Atlantic Subpolar gyre (NASPG) have been linked to the interannual variability of primary production. However, little is known about the mechanisms behind both environmental processes, and how the NASPG strength may extend its potential impacts to higher trophic levels, including early life stages of commercial fish species. We assess NASPG strength effect on North Atlantic phytoplankton bloom dynamics. We analyse time‐series (from 1998 to 2010) of chlorophyll a (Chl a, f...

  3. Causes of Low Frequency North Atlantic SST Variability in a Coupled GCM

    OpenAIRE

    Schneider, E.K.; Kirtman, B. P.; Wu, Z.

    2004-01-01

    The low frequency sea surface temperature (SST) variability in the North Atlantic is studied using the Center for Ocean-Land-Atmosphere Studies (COLA) anomaly coupled general circulation model. The main focus is placed on the relative roles of stable and unstable coupled feedbacks in inducing the low frequency SST variability in various regions of the North Atlantic. To examine this question, a recently developed coupling technique, interactive ensembles, is applied to reduce t...

  4. Influence of the North Atlantic SST Variability on the Atmospheric Circulation during the Twentieth Century

    OpenAIRE

    Gastineau, Guillaume; Frankignoul, Claude

    2015-01-01

    International audience The ocean–atmosphere coupling in the North Atlantic is investigated during the twentieth century using maximum covariance analysis of sea surface temperature (SST) and 500-hPa geopotential height analyses and performing regressions on dynamical diagnostics such as Eady growth rate, wave activity flux, and velocity potential. The North Atlantic Oscillation (NAO) generates the so-called SST anomaly tripole. A rather similar SST anomaly tripole, with the subpolar anomal...

  5. A composite annual-resolution stalagmite record of North Atlantic climate over the last three millennia

    OpenAIRE

    Andy Baker; Hellstrom, John C.; Kelly, Bryce F. J.; Gregoire Mariethoz; Valerie Trouet

    2015-01-01

    Annually laminated stalagmites can be used to construct a precise chronology, and variations in laminae thickness provide an annual growth-rate record that can be used as a proxy for past climate and environmental change. Here, we present and analyse the first composite speleothem annual growth-rate record based on five stalagmites from the same cave system in northwest Scotland, where precipitation is sensitive to North Atlantic climate variability and the winter North Atlantic Oscillation (...

  6. Atmospheric multidecadal variations in the North Atlantic realm: proxy data, observations, and atmospheric circulation model studies

    OpenAIRE

    Grosfeld, K.; G. Lohmann; N. Rimbu; Fraedrich, K.; F. Lunkeit

    2007-01-01

    We investigate the spatial and temporal characteristics of multidecadal climate variability in the North Atlantic realm, using observational data, proxy data and model results. The dominant pattern of multidecadal variability of SST depicts a monopolar structure in the North Atlantic during the instrumental period with cold (warm) phases during 1900–1925 and 1970–1990 (1870–1890 and 1940–1960). Two atmospheric general circulation models of different com...

  7. The atmospheric response to North Atlantic SST anomalies in seasonal prediction experiments

    OpenAIRE

    Lin, Hai; DEROME, JACQUES

    2011-01-01

    Seasonal forecasts performed over a 26 yr period as part of the Historical Seasonal Forecasting Project (HFP) are used to analyze the influence of North Atlantic sea surface temperature (SST) anomalies on the atmospheric circulation, its seasonality, and model dependence. The signals related to the El Ni˜no events are first removed from both the SST and the atmospheric data. The North Atlantic SST and the ensemble mean forecast are then correlated over the 26 yr to identify the model response...

  8. Dangerous dining: surface foraging of North Atlantic right whales increases risk of vessel collisions

    OpenAIRE

    Susan E Parks; Warren, Joseph D.; Stamieszkin, Karen; Mayo, Charles A.; Wiley, David

    2011-01-01

    North Atlantic right whales are critically endangered and, despite international protection from whaling, significant numbers die from collisions with ships. Large groups of right whales migrate to the coastal waters of New England during the late winter and early spring to feed in an area with large numbers of vessels. North Atlantic right whales have the largest per capita record of vessel strikes of any large whale population in the world. Right whale feeding behaviour in Cape Cod Bay (CCB...

  9. North America's Midcontinent Rift: when Rift MET Lip

    Science.gov (United States)

    Stein, C. A.; Stein, S. A.; Kley, J.; Keller, G. R., Jr.; Bollmann, T. A.; Wolin, E.; Zhang, H.; Frederiksen, A. W.; Ola, K.; Wysession, M. E.; Wiens, D.; Alequabi, G.; Waite, G. P.; Blavascunas, E.; Engelmann, C. A.; Flesch, L. M.; Rooney, T. O.; Moucha, R.; Brown, E.

    2015-12-01

    Rifts are segmented linear depressions, filled with sedimentary and igneous rocks, that form by extension and often evolve into plate boundaries. Flood basalts, a class of Large Igneous Provinces (LIPs), are broad regions of extensive volcanism due to sublithospheric processes. Typical rifts are not filled with flood basalts, and typical flood basalts are not associated with significant crustal extension and faulting. North America's Midcontinent Rift (MCR) is an unusual combination. Its 3000-km length formed as part of the 1.1 Ga rifting of Amazonia (Precambrian NE South America) from Laurentia (Precambrian North America) and became inactive once seafloor spreading was established, but contains an enormous volume of igneous rocks. MCR volcanics are significantly thicker than other flood basalts, due to deposition in a narrow rift rather than a broad region, giving a rift geometry but a LIP's magma volume. Structural modeling of seismic reflection data shows an initial rift phase where flood basalts filled a fault-controlled extending basin, and a postrift phase where volcanics and sediments were deposited in a thermally subsiding basin without associated faulting. The crust thinned during rifting and rethickened during the postrift phase and later compression, yielding the present thicker crust. The coincidence of a rift and LIP yielded the world's largest deposit of native copper. This combination arose when a new rift associated with continental breakup interacted with a mantle plume or anomalously hot or fertile upper mantle. Integration of diverse data types and models will give insight into questions including how the magma source was related to the rifting, how their interaction operated over a long period of rapid plate motion, why the lithospheric mantle below the MCR differs only slightly from its surroundings, how and why extension, volcanism, and compression varied along the rift arms, and how successful seafloor spreading ended the rift phase. Papers

  10. Atlantic salmon, Salmo salar L. are broadly susceptible to isolates representing the North American genogroups of infectious hematopoietic necrosis virus

    Science.gov (United States)

    Kurath, Gael; Winton, James R.; Dale, Ole Bendik; Purcell, Maureen K.; Falk, Knut; Busch, Robert D.

    2016-01-01

    Beginning in 1992, three epidemic waves of infectious hematopoietic necrosis, often with high mortality, occurred in farmed Atlantic salmon Salmo salar L. on the west coast of North America. We compared the virulence of eleven strains of infectious hematopoietic necrosis virus (IHNV), representing the U, M and L genogroups, in experimental challenges of juvenile Atlantic salmon in freshwater. All strains caused mortality and there was wide variation within genogroups: cumulative mortality for five U-group strains ranged from 20 to 100%, four M-group strains ranged 30-63% and two L-group strains varied from 41 to 81%. Thus, unlike Pacific salmonids, there was no apparent correlation of virulence in a particular host species with virus genogroup. The mortality patterns indicated two different phenotypes in terms of kinetics of disease progression and final per cent mortality, with nine strains having moderate virulence and two strains (from the U and L genogroups) having high virulence. These phenotypes were investigated by histopathology and immunohistochemistry to describe the variation in the course of IHNV disease in Atlantic salmon. The results from this study demonstrate that IHNV may become a major threat to farmed Atlantic salmon in other regions of the world where the virus has been, or may be, introduced.

  11. Factors affecting expanded electricity trade in North America

    Energy Technology Data Exchange (ETDEWEB)

    Hill, L.J.

    1994-01-01

    The authors explore factors that affect electricity trade between enterprises in the US and Canada and the US and Mexico. They look to those underlying policy and institutional factors that affect the relative costs of producing electricity in the three countries. In particular, they consider six factors that appear to have a significant impact on electricity trade in North America: differences in the types of economic regulation of power leading to differences in cost recovery for wholesale and retail power and wheeling charges; changing regulatory attitudes, placing more emphasis on demand-side management and environmental concerns; differences in energy and economic policies; differences in national and subnational environmental policies; changing organization of electric power industries which may foster uncertainty, change historical relationships, and provide other potentially important sources of power for distribution utilities; and differences in the ability of enterprises to gain access to electric power markets because of restrictions placed on transmission access. In Section 2, the authors discuss the regulation of electricity trade in North America and provide an overview of the recent trading experience for electricity between Canada and the US and between Mexico and the US, including the volume of that trade over the past decade and existing transmission capacity between regions of the three countries. In Section 3, they look at the benefits that accrue to trading counties and what those benefits are likely to be for the three countries. The discussion in Section 4 centers on the relevant provisions of the Canada Free Trade Agreement and the proposed North American Free Trade Agreement. In Section 5, they set the stage for the discussion of policy and institutional differences presented in Section 6 by outlining differences in the organization of the electric power sectors of Canada, the US, and Mexico. The study is synthesized in Section 7.

  12. North Tropical Atlantic influence on western Amazon fire season variability

    Science.gov (United States)

    Fernandes, Katia; Baethgen, Walter; Bernardes, Sergio; DeFries, Ruth; DeWitt, David G.; Goddard, Lisa; Lavado, Waldo; Lee, Dong Eun; Padoch, Christine; Pinedo-Vasquez, Miguel; Uriarte, Maria

    2011-06-01

    The prevailing wet climate in the western Amazon is not favorable to the natural occurrence of fires. Nevertheless, the current process of clearing of humid forests for agriculture and cattle ranching has increased the vulnerability of the region to the spread of fires. Using meteorological stations precipitation and the Moderate Resolution Spectroradiometer (MODIS) Active-Fires (AF) during 2000-2009, we show that fire anomalies vary closely with July-August-September (JAS) precipitation variability as measured by the Standardized Precipitation Index (SPI). The precipitation variability is, in turn, greatly determined by sea surface temperature (SST) anomalies in the North Tropical Atlantic (NTA). We develop a linear regression model to relate local fire activity to an index of the NTA-SST. By using seasonal forecasts of SST from a coupled model, we are able to predict anomalous JAS fire activity as early as April. We applied the method to predict the severe 2010 JAS season, which indicated strongly positive seasonal fire anomalies within the 95% prediction confidence intervals in most western Amazon. The spatial distribution of predicted SPI was also in accordance with observed precipitation anomalies. This three months lead time precipitation and fire prediction product in the western Amazon could help local decision makers to establish an early warning systems or other appropriate course of action before the fire season begins.

  13. BrO measurements over the Eastern North-Atlantic

    Directory of Open Access Journals (Sweden)

    M. Martin

    2009-04-01

    Full Text Available The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many was, e.g. since it catalytically destroys ozone, changes the NO2/NO-ratio as well as the OH/HO2-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere are not yet fully understood.

    We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN. Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7 ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from the African coast.

  14. BrO measurements over the Eastern North-Atlantic

    Directory of Open Access Journals (Sweden)

    U. Platt

    2009-12-01

    Full Text Available The aim of the work presented here was to detect BrO in the marine boundary layer over the Eastern North-Atlantic by Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS of scattered sunlight. With this technique, information about the concentration and the vertical profile of trace gases in the atmosphere can be gained. BrO can be formed in the marine atmosphere by degradation of biogenic organohalogens or by oxidation of bromide in sea salt aerosol. BrO influences the chemistry in marine air in many ways, e.g. since it catalytically destroys ozone, changes the NO2/NO-ratio as well as the OH/HO2-ratio and oxidises DMS. However, the abundance and the significance of BrO in the marine atmosphere is not yet fully understood.

    We report on data collected during a ship cruise, which took place along the West African Coast in February 2007, within the framework of the Surface Ocean PRocesses in the ANthropocene project (SOPRAN. Tropospheric BrO could be detected during this cruise at peak mixing ratios of (10.2±3.7 ppt at an assumed layer height of 1 km on 18 February 2007. Furthermore, it was found that the mean BrO concentrations increased when cruising close to the African Coast suggesting that at least part of the BrO might have originated from there.

  15. North Atlantic climate variability in coupled models and data

    Directory of Open Access Journals (Sweden)

    S. K. Kravtsov

    2008-01-01

    Full Text Available We show that the observed zonally averaged jet in the Northern Hemisphere atmosphere exhibits two spatial patterns with broadband variability in the decadal and inter-decadal range; these patterns are consistent with an important role of local, mid-latitude ocean–atmosphere coupling. A key aspect of this behaviour is the fundamentally nonlinear bi-stability of the atmospheric jet's latitudinal position, which enables relatively small sea-surface temperature anomalies associated with ocean processes to affect the large-scale atmospheric winds. The wind anomalies induce, in turn, complex three-dimensional anomalies in the ocean's main thermocline; in particular, they may be responsible for recently reported cooling of the upper ocean. Both observed modes of variability, decadal and inter-decadal, have been found in our intermediate climate models. One mode resembles North Atlantic tri-polar sea-surface temperature (SST patterns described elsewhere. The other mode, with mono-polar SST pattern, is novel; its key aspects include interaction of oceanic turbulence with the large-scale oceanic flow. To the extent these anomalies exist, the interpretation of observed climate variability in terms of natural and human-induced changes will be affected. Coupled mid-latitude ocean-atmosphere modes do, however, suggest some degree of predictability is possible.

  16. Estimating the Length of the North Atlantic Basin Hurricane Season

    Science.gov (United States)

    Wilson, Robert M.

    2012-01-01

    For the interval 1945-2011, the length of the hurricane season in the North Atlantic basin averages about 130 +/- 42 days (the +/-1 standard deviation interval), having a range of 47 to 235 days. Runs-testing reveals that the annual length of season varies nonrandomly at the 5% level of significance. In particular, its trend, as described using 10-yr moving averages, generally has been upward since about 1979, increasing from about 113 to 157 days (in 2003). Based on annual values, one finds a highly statistically important inverse correlation at the 0.1% level of significance between the length of season and the occurrence of the first storm day of the season. For the 2012 hurricane season, based on the reported first storm day of May 19, 2012 (i.e., DOY = 140), the inferred preferential regression predicts that the length of the current season likely will be about 173 +/- 23 days, suggesting that it will end about November 8 +/- 23 days, with only about a 5% chance that it will end either before about September 23, 2012 or after about December 24, 2012.

  17. Interannual to decadal predictability in the North Atlantic Europe region

    Science.gov (United States)

    Jouzeau, A.; Terray, L.

    2003-04-01

    A 200-year control experiment is performed with the third version of the ARPEGE-Climat atmospheric model coupled to the ORCALIM2 (ORCA/Louvain Ice Model) sea-ice/ocean model. This study takes place in the framework of the PREDICATE project. The simulation shows low frequency fluctuations (period of 30-50 years) in the Thermohaline Circulation (THC) of about 15% of the mean transport. Two 25-year long ensemble experiments are then conducted, contrasting opposite phases of the THC: the first ensemble starts at a maximum of the intensity of the THC, the second one at a minimum. For each ensemble, the different members (6 members for each ensemble) only differ by infinitesimal perturbations of their initial atmospheric conditions. We use these ensembles to study the potential predictability at interannual to decadal time scales. The preliminary results suggest the existence of predictability up to several years in the THC and SST in the North Atlantic. On the other hand, there seems to be very little predictability (beyond one year) arising from atmospheric variables. These results are obtained using a simple predictability index introduced by Collins and Allen (2001) which measures the rate of spread of the ensembles of simulations against climatology. A cluster analysis will then be performed to investigate the modification of the frequency of occurrence of the main climatic regimes and their links with the THC states.

  18. North Pacific seasonality and the glaciation of North America 2.7 million years ago

    OpenAIRE

    Haug, G. H.; Ganopolski, A.; Sigman, D. M.; Rosell-Mele, A.; G. E. A. Swann; R. Tiedemann; S. L. Jaccard; J. Bollmann; Maslin, M. A.; Leng, M. J.; Eglinton, G.;  ,

    2005-01-01

    In the context of gradual Cenozoic cooling, the timing of the onset of significant Northern Hemisphere glaciation 2.7 million years ago is consistent with Milankovitch’s orbital theory, which posited that ice sheets grow when polar summertime insolation and temperature are low. However, the role of moisture supply in the initiation of large Northern Hemisphere ice sheets has remained unclear. The subarctic Pacific Ocean represents a significant source of water vapour to boreal North America, ...

  19. Effects of tropical North Atlantic SST on tropical cyclone genesis in the western North Pacific

    Science.gov (United States)

    Yu, Jinhua; Li, Tim; Tan, Zhemin; Zhu, Zhiwei

    2016-02-01

    The tropical cyclone genesis number (TCGN) in July-October (JASO) over the western North Pacific (WNP) exhibits a robust interannual variation. It shows a longitudinally tri-pole pattern with a high in the eastern WNP and South China Sea (SCS) and a low in the western WNP, which explain 42.2 and 23.4 % of total TCGN variance in the eastern WNP and SCS, respectively. The high-low-high pattern is similar to that derived from a TC genesis potential index (GPI). To understand the cause of the longitudinal distribution of the dominant interannual mode, we examine the contributions of environmental parameters associated with GPI. It is found that relative humidity and relative vorticity are important factors responsible for TC variability in the SCS, while vertical shear and relative vorticity are crucial in determining TC activity in eastern WNP. A simultaneous correlation analysis shows that the WNP TCGN in JASO is significantly negatively correlated (with a correlation coefficient of -0.5) with sea surface temperature anomalies (SSTA) in the tropical North Atlantic (TNA). The longitudinal distribution of TC genesis frequency regressed onto TNA SSTA resembles that regressed upon the WNP TCGN series. The spatial patterns of regressed environmental variables onto the SSTA over the TNA also resemble those onto TCGN in the WNP, that is, an increase of relative humidity in the SCS and a weakening of vertical shear in the eastern WNP are all associated with cold SSTA in the TNA. Further analyses show that the cold SSTA in the TNA induce a negative heating in situ. In response to this negative heating, a low (upper)-level anomalous aniti-cyclonic (cyclonic) flows appear over the subtropical North Atlantic and eastern North Pacific, and to east of the cold SSTA, anomalous low-level westerlies appear in the tropical Indian Ocean. Given pronounced mean westerlies in northern Indian Ocean in boreal summer, the anomalous westerly flows increase local surface wind speed and surface

  20. Surface changes in the North Atlantic meridional overturning circulation during the last millennium.

    Science.gov (United States)

    Wanamaker, Alan D; Butler, Paul G; Scourse, James D; Heinemeier, Jan; Eiríksson, Jón; Knudsen, Karen Luise; Richardson, Christopher A

    2012-01-01

    Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation dynamics likely amplified the relatively warm conditions during the Medieval Climate Anomaly and the relatively cool conditions during the Little Ice Age within the North Atlantic sector. PMID:22692542

  1. Hydrography and through-flow in the north-eastern North Atlantic Ocean: the NANSEN project

    Science.gov (United States)

    van Aken, H. M.; Becker, G.

    The circulation and hydrography of the north-eastern North Atlantic has been studied with an emphasis on the upper layers and the deep water types which take part in the thermohaline overturning of the Oceanic Conveyor Belt. Over 900 hydrographic stations were used for this study, mainly from the 1987-1991 period. The hydrographic properties of Subpolar Mode Water in the upper layer, which is transported towards the Norwegian Sea, showed large regional variation. The deep water mass was dominated by the cold inflow of deep water from the Norwegian Sea and by a cyclonic recirculation of Lower Deep Water with a high Antarctic Bottom Water content. At intermediate levels the dominating water type was Labrador Sea Water with only minor influence of Mediterranean Sea Water. In the permanent pycnocline traces of Antarctic Intermediate Water were found. Geostrophic transports have been estimated, and these agreed in order of magnitude with the local heat budget, with current measurements, with data from surface drifters, and with the observed water mass modification. A total of 23 Sv of surface water entered the region, of which 20 Sv originated from the North Atlantic Current, while 3 Sv entered via an eastern boundary current. Of this total, 13 Sv of surface water left the area across the Reykjanes Ridge, and 7 Sv entered the Norwegian Sea, while 3 Sv was entrained by the cold overflow across the Iceland-Scotland Ridge. Approximately 1.4 Sv of Norwegian Sea Deep Water was involved in the overflow into the Iceland Basin, which, with about 1.1 Sv of entrained water and 1.1 Sv recirculating Lower Deep Water, formed a deep northern boundary current in the Iceland Basin. At intermediate depths, where Labrador Sea Water formed the dominant water type, about 2 Sv of entrained surface water contributed to a saline water mass which was transported westwards along the south Icelandic slope.

  2. Potential for a Second Generation of Emerging Vector Borne Diseases in North America

    Science.gov (United States)

    North America has been dealing with the consequences of the introduction of West Nile virus since it was first discovered in New York City in 1999. Currently there are numerous other vector-borne pathogens that occur in various parts of the world that could be introduced into North America and becom...

  3. Cross-continental patterns in the timing of southward Peregrine Falcon migration in North America

    NARCIS (Netherlands)

    Worcester, R.; Ydenberg, R.C.

    2008-01-01

    We analyzed the timing of southward migration of Peregrine Falcons (Falco peregrinus) across North America, based on passage data compiled by the Hawk Migration Association of North America, supplemented with two other similar datasets collected by individual observers at sites in western Canada. Th

  4. 78 FR 76408 - BMW of North America, LLC, Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2013-12-17

    ... Register (77 FR 63415). One comment was received from Anne K. Mayer which supported granting BMW's petition... National Highway Traffic Safety Administration BMW of North America, LLC, Grant of Petition for Decision of... Transportation (DOT). ACTION: Grant of Petition. SUMMARY: BMW North America, LLC,\\1\\ a subsidiary of BMW...

  5. 76 FR 12410 - BMW of North America, LLC, Receipt of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2011-03-07

    ... complete Privacy Act Statement is in the Federal Register published on April 11, 2000 (65 FR 19477-78). You... National Highway Traffic Safety Administration BMW of North America, LLC, Receipt of Petition for Decision of Inconsequential Noncompliance BMW of North America, LLC (BMW) \\1\\ a subsidiary of BMW AG,...

  6. 77 FR 16892 - BMW of North America, LLC, Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2012-03-22

    ... Federal Register (76 FR 12410). No comments were received. To view the petition and all supporting... National Highway Traffic Safety Administration BMW of North America, LLC, Grant of Petition for Decision of... Petition Grant. SUMMARY: BMW of North America, LLC (BMW) \\1\\ a subsidiary of BMW AG, Munich, Germany,...

  7. Coherent decadal sea level variations across gyre boundaries in the North Atlantic

    Science.gov (United States)

    Thompson, P. R.; Mitchum, G. T.

    2010-12-01

    Tide gauge sea level variability in the western Atlantic at periods greater than about 18 months is in phase and highly coherent from Texas to Nova Scotia. A simple mean over the gauges analyzed in this region explained more than 50% of the total variance in the gauges and has a primary time-scale of variation in the decadal band. Decadal sea level variability in the western Atlantic is most often attributed to open ocean wind forcing and long Rossby waves, which act to spin up or spin down the subtropical gyre. However, this explanation is not sufficient to explain why sea levels along the coastal edge of the Gulf Stream are in phase and highly correlated with sea levels in the Gulf of Mexico and subpolar gyre. Furthermore, there is evidence that decadal variations in North American sea levels are coherent and of opposite phase with respect to gauges along the European coast of the subtropical gyre, which is not expected from a mechanism requiring westward propagation. A linear regression of North Atlantic sea surface temperature onto the composite low-passed sea level signal from around the North Atlantic showed a basin-wide pattern of sea surface temperature similar to the North Atlantic Tripole (NAT) identified in various studies of decadal climate variability in the North Atlantic. The emergence of the NAT pattern from tide gauge sea levels suggested the low-frequency coherence of sea level is indicative of a basin-scale decadal climate mode and that the steric contribution to decadal sea level variability in the Gulf Stream region is as important as the dynamic contribution from open ocean wind forcing. We explored the relative roles of dynamic and steric sea level change in the coherent nature of decadal sea level signals around the North Atlantic basin, and we propose basin-scale mechanisms to link decadal sea level change between the gyres and zonally across the Atlantic.

  8. Assessment of sea surface temperature variations in the central North Atlantic using the alkenone unsaturation index (U 37k')

    Science.gov (United States)

    Villanueva, Joan; Grimalt, Joan O.; Cortijo, Elsa; Vidal, Laurence; Labeyrie, Laurent

    1998-07-01

    A high resolution record of U 37k' -derived SST estimations has been obtained in a core from the central North Atlantic Ocean (SU90/08, 43°30'N, 30°24'W) spanning a time period of 280 ky. The general trend of the U 37k' profile parallels closely the δ 180 signal and represent an independent confirmation that the SST variations in the glacial-interglacial time scales are correlated with the northern ice sheets evolution. In contrast to the CLIMAP (1984) conclusions based on the foraminiferal transfer function technique, the SST during the last interglacial period (LIP, isotopic stage 5.5) are 2-3°C warmer than during the Holocene. This result is in good agreement with many studies based in coastal and continental records that strongly suggest warmer climatic conditions over North America and Europe. Finally, the SST estimates during the last glacial maximum (LGM, 18 ky BP) where 4.5°C cooler than during the previous glacial period (PGP, stage 6). We argue that this difference is caused by a northward position of the polar front during the PGP in the Central North Atlantic.

  9. A survey of transmission tariffs in North America

    International Nuclear Information System (INIS)

    One goal of electricity restructuring is to facilitate voluntary transactions in workably competitive wholesale electricity markets. Unfettered wholesale trading, however, can only take place under open and comparable access to transmission by all market participants at non-discriminatory tariffs. Since a rich body of literature exists for topics like nodal pricing, transmission rights, ancillary services, and optimal dispatch, this paper's focus is to survey the transmission tariffs actually used in North America to achieve open and comparable transmission access. In doing so, it provides a practical guide to developing a transmission tariff, illustrated by the survey's role in shaping the tariff filed by a company like the British Columbia Transmission Company (BCTC) with its regulator, the British Columbia Utilities Commission (BCUC). (author)

  10. Recent trends in gas contracting in North America

    International Nuclear Information System (INIS)

    An overview of recent business trends impacting upon natural gas contracting in North America is provided. Among the trends examined are supply and demand, natural gas prices, access to the U.S. market, gas sales contracts, electronic gas sales, retail level marketing, the growing popularity of 'one-stop shopping', and standardization of contracts. Overall, supplies appear to be adequate for now, demand is growing, prices are volatile, short-term contracts are more popular than long-term ones, electronic commerce combined with one-stop shopping marketing at the retail level is growing, and standardization of spot and short-term gas sales contracts is slowly being accepted by industry as a means to to improve the efficiency of the market. 12 refs

  11. Reducing inequities in colorectal cancer screening in North America

    Directory of Open Access Journals (Sweden)

    Kathleen M Decker

    2014-01-01

    Full Text Available Colorectal cancer (CRC is an important cause of mortality and morbidity in North America. Screening using a fecal occult blood test, flexible sigmoidoscopy, or colonoscopy reduces CRC mortality through the detection and treatment of precancerous polyps and early stage CRC. Although CRC screening participation has increased in recent years, large inequities still exist. Minorities, new immigrants, and those with lower levels of education or income are much less likely to be screened. This review provides an overview of the commonly used tests for CRC screening, disparities in CRC screening, and promising methods at the individual, provider, and system levels to reduce these disparities. Overall, to achieve high CRC participation rates and reduce the burden of CRC in the population, a multi-faceted approach that uses strategies at all levels to reduce CRC screening disparities is urgently required.

  12. Why different gas flux velocity parameterizations result in so similar flux results in the North Atlantic?

    Science.gov (United States)

    Piskozub, Jacek; Wróbel, Iwona

    2016-04-01

    The North Atlantic is a crucial region for both ocean circulation and the carbon cycle. Most of ocean deep waters are produced in the basin making it a large CO2 sink. The region, close to the major oceanographic centres has been well covered with cruises. This is why we have performed a study of net CO2 flux dependence upon the choice of gas transfer velocity k parameterization for this very region: the North Atlantic including European Arctic Seas. The study has been a part of a ESA funded OceanFlux GHG Evolution project and, at the same time, a PhD thesis (of I.W) funded by Centre of Polar Studies "POLAR-KNOW" (a project of the Polish Ministry of Science). Early results have been presented last year at EGU 2015 as a PICO presentation EGU2015-11206-1. We have used FluxEngine, a tool created within an earlier ESA funded project (OceanFlux Greenhouse Gases) to calculate the North Atlantic and global fluxes with different gas transfer velocity formulas. During the processing of the data, we have noticed that the North Atlantic results for different k formulas are more similar (in the sense of relative error) that global ones. This was true both for parameterizations using the same power of wind speed and when comparing wind squared and wind cubed parameterizations. This result was interesting because North Atlantic winds are stronger than the global average ones. Was the flux result similarity caused by the fact that the parameterizations were tuned to the North Atlantic area where many of the early cruises measuring CO2 fugacities were performed? A closer look at the parameterizations and their history showed that not all of them were based on North Atlantic data. Some of them were tuned to the South Ocean with even stronger winds while some were based on global budgets of 14C. However we have found two reasons, not reported before in the literature, for North Atlantic fluxes being more similar than global ones for different gas transfer velocity parametrizations

  13. Relation between the wind stress curl in the North Atlantic and the Atlantic inflow to the Nordic Seas

    OpenAIRE

    Sandø, Anne Britt; Furevik, Tore

    2008-01-01

    In this study an isopycnic coordinate ocean model has been used to investigate the relationships between the North Atlantic wind stress curl (WSC) and the inflow of Atlantic water to the Nordic Seas. For the period 1995–2001, there is a maximum in the correlation between the zonally averaged WSC at 55!N and the inflow with a 15-month time lag, capturing a relation already found in observational data. In the model this relation is linked to the mixing along the western flank of the...

  14. Temperature fluctuations in the Atlantic Ocean

    International Nuclear Information System (INIS)

    The article discusses the temperature fluctuations in connection with drought in Africa, the climate in North America, the European heat waves and the frequent tropical hurricanes in the Atlantic Ocean. Problems with climate modelling and some pollution aspects are mentioned

  15. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

    Science.gov (United States)

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-05-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  16. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America

    Science.gov (United States)

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A.; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L.; Pharr, G. Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    SUMMARY Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts including avian, swine, equine, canine, and sea mammals. These H3 viruses are both antigenically and genetically diverse. Here we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other, and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about 4 units, and each unit corresponds to a 2log2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  17. EGFR Expression in Gallbladder Carcinoma in North America

    Directory of Open Access Journals (Sweden)

    Matthew Kaufman, Bhoomi Mehrotra, Sewanti Limaye, Sherrie White, Alexander Fuchs, Yehuda Lebowicz, Sandy Nissel-Horowitz, Adrienne Thomas

    2008-01-01

    Full Text Available BACKGROUND: Increased epidermal growth factor receptor (EGF receptor expression has been noted in various cancers and has become a useful target for therapeutic interventions. Small studies from Asia and Australia have demonstrated EGFR over-expression in gallbladder cancer. We sought to evaluate the expression of EGFR in a series of 16 gallbladder cancer patients from North America. METHODS: Using tumor registry data, we identified 16 patients diagnosed with gall bladder carcinoma at our medical center between the years of 1998 and 2005. We performed a retrospective review of these patients' charts, obtained cell blocks from pathology archives and stained for EGFR and Her2/neu. RESULTS: Fifteen of sixteen patients were noted to over-express EGFR. Three were determined 1+, nine were 2+ and three were 3+. Eight patients had poorly differentiated adenocarcinoma, six had moderately differentiated and two had well-differentiated tumors. In this small series, there was a trend toward shorter survival and more poorly differentiated tumors in patients with greater intensity of EGFR expression. One patient was EGFR negative but 3+ for erb-2/Her 2-neu expression. No patient co-expressed EGFR and Her-2-neu. Median survival of patients in this series was 17 months. CONCLUSION: In view of our observations confirming the over-expression of EGFR in our patient population in North America, and the recent success of EGFR targeted therapies in other solid tumors that over-express EGFR, it may now be appropriate to evaluate agents targeting this pathway either as single agents or in combination with standard chemotherapy.

  18. Free tropospheric transport of microorganisms from Asia to North America

    Science.gov (United States)

    D. Smith; Dan Jaffe; Michele Birmele; Griffin, Dale W.; Andrew Schuerger; Hee, J.; Michael Roberts

    2012-01-01

    Microorganisms are abundant in the troposphere and can be transported vast distances on prevailing winds. This study measures the abundance and diversity of airborne bacteria and fungi sampled at the Mt. Bachelor Observatory (located 2.7 km above sea level in North America) where incoming free tropospheric air routinely arrives from distant sources across the Pacific Ocean, including Asia. Overall deoxyribonucleic acid (DNA) concentrations for microorganisms in the free troposphere, derived from quantitative polymerase chain reaction assays, averaged 4.94 × 10(-5) ng DNA m(-3) for bacteria and 4.77 × 10(-3) ng DNA m(-3) for fungi. Aerosols occasionally corresponded with microbial abundance, most often in the springtime. Viable cells were recovered from 27.4 % of bacterial and 47.6 % of fungal samples (N = 124), with 49 different species identified by ribosomal DNA gene sequencing. The number of microbial isolates rose significantly above baseline values on 22-23 April 2011 and 13-15 May 2011. Both events were analyzed in detail, revealing distinct free tropospheric chemistries (e.g., low water vapor, high aerosols, carbon monoxide, and ozone) useful for ruling out boundary layer contamination. Kinematic back trajectory modeling suggested air from these events probably originated near China or Japan. Even after traveling for 10 days across the Pacific Ocean in the free troposphere, diverse and viable microbial populations, including presumptive plant pathogens Alternaria infectoria and Chaetomium globosum, were detected in Asian air samples. Establishing a connection between the intercontinental transport of microorganisms and specific diseases in North America will require follow-up investigations on both sides of the Pacific Ocean.

  19. Assessing The Effectiveness Of Soil Carbon Sequestration In North America

    Science.gov (United States)

    Jain, A. K.; Yang, X.; Post, W.

    2006-12-01

    Soil carbon sequestration has been shown to be an important part of a portfolio of carbon sequestration strategies in the U.S. and Canada, and one that can be implemented at relatively low costs. This analysis focuses on the estimate of carbon sequestration in soil as a result of a change from conventional plow tillage (CT) to no-till (NT) in North America and the resulting uptake of CO2 from 1981-2000. We use the terrestrial component of the Integrated Science Assessment Model (ISAM-2), which simulates carbon and nitrogen fluxes as well as the interactions between carbon cycle and nitrogen cycle within the terrestrial biosphere at a 0.5o x 0.5o spatial resolution. To estimate carbon sequestration in soils, following a change in cropland management from CT to NT, we implement empirically-based sequestration estimates, or CMR curves in the ISAM. The CMR curves are based on the mean annual change in soil carbon over the expected duration of active sequestration. These empirical relationships have been developed for changes from CT to NT for five different climate regions, which are consistent with those used in the IPCC guidelines for carbon accounting. To calculate sequestration rates in North America, we use the measured area under NT over the period 1981- 2000. Cropland management (CT to NT) is accompanied by changes in CO2 concentration, climate, land use and land cover, and nitrogen deposition. Since these changes affect carbon and nitrogen cycles, and the interaction between them, which could augment or lessen carbon sequestration, we take a holistic approach to study carbon sequestration by incorporating major environmental changes.

  20. Structure and dynamics of basin forested wetlands in North America

    International Nuclear Information System (INIS)

    Freshwater basin wetlands are found in depressions of various depths, generally in areas where precipitation exceeds evapotranspiration or where the depression intersects the water table creating groundwater seeps or springs. Forested basins are those that contain woody vegetation with the potential for reaching tree stature; they do not include woody shrub wetlands. In North America these areas are mainly in the central and eastern region. Pertinent information and reviews on the distribution, floristic composition, structure and dynamics of basin forested wetlands are summarized. The major emphasis is on freshwater wetlands, but data for saltwater wetlands mainly from Florida and tropical America are included. The external factors affecting basin wetlands or the important components of a wetlands energy signature are described as well as the distribution and floristic composition of representative basin wetlands. Sections on structural characteristics, organic matter dynamics, and nutrient cycling comprise the bulk of quantitative information. The effects of disturbances, both natural and human induced, with varying degrees of impact depending upon the intensity and on the part of the ecosystem to which the stressor is applied are evaluated. Examples of stressors in basin wetlands include water impoundment, water diversion, thermal stress from hot water, sedimentation, addition of toxic substances, addition of wastewater, oil spills, and harvesting. 86 refs., 5 figs., 11 tabs

  1. Troposphere–stratosphere response to large-scale North Atlantic Ocean variability in an atmosphere/ocean coupled model

    OpenAIRE

    Omrani, N.; Bader, J.; Keenlyside, N.; E. Manzini

    2016-01-01

    The instrumental records indicate that the basin-wide wintertime North Atlantic warm conditions are accompanied by a pattern resembling negative North Atlantic oscillation (NAO), and cold conditions with pattern resembling the positive NAO. This relation is well reproduced in a control simulation by the stratosphere resolving atmosphere–ocean coupled Max-Planck-Institute Earth System Model (MPI-ESM). Further analyses of the MPI-ESM model simulation shows that the large-scale warm North Atlant...

  2. Prediction skill of monthly SST in the North Atlantic Ocean in NCEP Climate Forecast System version 2

    Science.gov (United States)

    Hu, Zeng-Zhen; Kumar, Arun; Huang, Bohua; Wang, Wanqiu; Zhu, Jieshun; Wen, Caihong

    2013-06-01

    This work evaluates the skill of retrospective predictions of the second version of the NCEP Climate Forecast System (CFSv2) for the North Atlantic sea surface temperature (SST) and investigates the influence of El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) on the prediction skill over this region. It is shown that the CFSv2 prediction skill with 0-8 month lead displays a "tripole"-like pattern with areas of higher skills in the high latitude and tropical North Atlantic, surrounding the area of lower skills in the mid-latitude western North Atlantic. This "tripole"-like prediction skill pattern is mainly due to the persistency of SST anomalies (SSTAs), which is related to the influence of ENSO and NAO over the North Atlantic. The influences of ENSO and NAO, and their seasonality, result in the prediction skill in the tropical North Atlantic the highest in spring and the lowest in summer. In CFSv2, the ENSO influence over the North Atlantic is overestimated but the impact of NAO over the North Atlantic is not well simulated. However, compared with CFSv1, the overall skills of CFSv2 are slightly higher over the whole North Atlantic, particularly in the high latitudes and the northwest North Atlantic. The model prediction skill beyond the persistency initially presents in the mid-latitudes of the North Atlantic and extends to the low latitudes with time. That might suggest that the model captures the associated air-sea interaction in the North Atlantic. The CFSv2 prediction is less skillful than that of SSTA persistency in the high latitudes, implying that over this region the persistency is even better than CFSv2 predictions. Also, both persistent and CFSv2 predictions have relatively low skills along the Gulf Stream.

  3. Harbour porpoises (Phocoena phocoena in the North Atlantic: Biological parameters

    Directory of Open Access Journals (Sweden)

    Christina Lockyer

    2013-10-01

    Full Text Available Biological parameters for harbour porpoises are reviewed throughout their range in the North Atlantic. Most information is based on studies of a combination of directed catches, bycatches and strandings. All these sources are valuable for providing biological information, but each carries some bias when it comes to interpretation of parameters, especially those involving age structure. Information on age-related parameters, reproduction and growth is presented and assessed by region and/or population, of which there may be 14 throughout the North Atlantic. Among age related parameters, maximum longevity recorded is 24 years; maximal rate of population growth is probably 9.4% but in the range 5-10%; mortality is highest in year 1, and <5% of the population live beyond 12 years; an estimate of 0.867 with a maximum age of 23 years has been given for survival. Among reproductive parameters, age at sexual maturation falls between 3-4 years for both sexes; age at first parturition is probably 4-5 years; age at first ovulation is >3 years; ovulation rates fall in the range 0.64 - 0.988 corpus per year, and reproductive interval is 1.01-1.57 years; pregnancy rates are generally in the range 0.74 - 0.986 per year, meaning that not all females produce a calf every year; there is seasonal breeding/mating in the period June–August; gestation lasts 10-11 months; parturition generally occurs between mid-May to mid-July; duration of lactation is uncertain, but is probably at least 8 months; size at birth is usually in the range 65-75 cm with a maximum size of about 80 cm. Sex ratio is biased to males throughout life: 1.1-1.2 males : 1.0 females in the foetal stage, and 1.1-1.7 males : 1.0 females post-natal. Growth parameters indicate an asymptotic length and weight that varies with population, but usually falls in the range 153-163 cm and 55-65 kg for females and 141-149 cm and 46-51 kg for males. Growth models used for length and weight

  4. Model investigations of the North Atlantic spring bloom initiation

    Science.gov (United States)

    Kuhn, Angela M.; Fennel, Katja; Mattern, Jann Paul

    2015-11-01

    The spring bloom - a massive growth of phytoplankton that occurs annually during the spring season in mid and high latitudes - plays an important role in carbon export to the deep ocean. The onset of this event has been explained from bottom-up and top-down perspectives, exemplified by the "critical-depth" and the "dilution-recoupling" hypotheses, respectively. Both approaches differ in their key expectations about how seasonal fluctuations of the mixed layer affect the plankton community. Here we assess whether the assumptions inherent to these hypotheses are met inside a typical onedimensional Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) model, optimized to best represent climatological annual cycles of satellite-based phytoplankton biomass in the Subpolar North Atlantic. The optimized model is used in idealized experiments that isolate the effects of mixed layer fluctuations and zooplankton grazing, in order to elucidate their significance. We analyzed the model sensitivity qualitatively and using a second-order Taylor series decomposition of the model equations. Our results show that the conceptual bases of both bottom-up and top-down approaches are required to explain the process of blooming; however, neither of their bloom initiation mechanisms fully applies in the experiments. We find that a spring bloom can develop in the absence of mixed layer fluctuations, and both its magnitude and timing seem to strongly depend on nutrient and light availability. Furthermore, although zooplankton populations modulate the phytoplankton concentrations throughout the year, directly prescribed and physically driven changes in zooplankton grazing do not produce significant time shifts in bloom initiation, as hypothesized. While recognizing its limitations, our study emphasizes the processes that require further testing in order to discern among competing hypotheses.

  5. Preparation of mercury emissions inventory for eastern North America.

    Science.gov (United States)

    Walcek, Chris; De Santis, Steven; Gentile, Thomas

    2003-01-01

    Point and area inventories of anthropogenic mercury emissions documented by US and Canadian environmental agencies have been aggregated into a single archive for analysis and air pollution modeling work. For 5341 point sources and 1634 aggregated area sources, mercury emissions are apportioned among elemental gaseous [Hg(0)], reactive gaseous[Hg(II)], and particulate [Hg(p)] emissions using speciation factors derived from available monitoring measurements. According to this inventory, 4.82 x 10(5) mol of mercury were emitted in calendar year 1996 in the latitude range 24-51 degrees north, and longitude range 64-91 degrees west, which covers most of North America east of the Mississippi River. Using speciation factors consistent with past emission source studies, we find the relative emission proportions among Hg(0):Hg(II):Hg(p) species are 47:35:18. Maps of the various mercury species' emissions patterns are presented. Gridded emission patterns show local mercury emission extremes associated with individual cement production and municipal incineration facilities, and in contrast to past inventories, population centers do not stand out. Considerable uncertainties are still present in estimating emissions from large point sources, as are methods of apportioning emissions among various mercury species. PMID:12667765

  6. BTU convergence spawning gas market opportunities in North America

    International Nuclear Information System (INIS)

    The so-called BTU convergence of US electric power and natural gas sectors is spawning a boom in market opportunities in the US Northeast that ensures the region will be North America's fastest growing gas market. That's the view of Catherine Good Abbott, CEO of Columbia Gas Transmission Corp., who told a Ziff Energy conference in Calgary that US Northeast gas demand is expected to increase to almost 10 bcfd in 2000 and more than 12 bcfd in 2010 from about 8 bcfd in 1995 and only 3 bcfd in 1985. The fastest growth will be in the US Northeast's electrical sector, where demand for gas is expected to double to 4 bcfd in 2010 from about 2 bcfd in 1995. In other presentations at the Ziff Energy conference, speakers voiced concerns about the complexity and speed of the BTU convergence phenomenon and offered assurances about the adequacy of gas supplies in North American to meet demand growth propelled by the BTU convergence boom. The paper discusses the gas demand being driven by power utilities, the BTU convergence outlook, electric power demand, Canadian production and supply, and the US overview

  7. The 2004 Sumatra tsunami as recorded on the Atlantic coast of South America

    Directory of Open Access Journals (Sweden)

    R. N. Candella

    2008-01-01

    Full Text Available The 2004 Sumatra tsunami propagated throughout the World Ocean and was clearly recorded by tide gauges on the Atlantic coast of South America. A total of 17 tsunami records were found and subsequently examined for this region. Tsunami wave heights and arrival times are generally consistent with numerical modeling results. Maximum wave heights of more than 1.2 m were observed on the coasts of Uruguay and southeastern Brazil. Marked differences in tsunami height from pairs of closely located tide gauge sites on the coast of Argentina illustrate the importance that local topographic resonance effects can have on the observed wave response. Findings reveal that, outside the Indian Ocean, the highest waves were recorded in the South Atlantic and not in the Pacific as has been previously suggested.

  8. Nested-grid simulation of mercury over North America

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2012-01-01

    Full Text Available We have developed a new high-resolution (1/2° latitude by 2/3° longitude nested-grid mercury (Hg simulation over North America employing the GEOS-Chem global chemical transport model. Emissions, chemistry, deposition, and meteorology are self-consistent between the global and nested domains. Compared to the global model (4° latitude by 5° longitude, the nested model shows improved skill at capturing the high spatial and temporal variability of Hg wet deposition over North America observed by the Mercury Deposition Network (MDN in 2008–2009. The nested simulation resolves features such as land/ocean contrast and higher deposition due to orographic precipitation, and predicts more efficient convective rain scavenging of Hg over the southeast United States. However, the nested model overestimates Hg wet deposition over the Ohio River Valley region (ORV by 27%. We modify anthropogenic emission speciation profiles in the US EPA National Emission Inventory (NEI to account for the rapid in-plume reduction of reactive to elemental Hg (IPR simulation. This leads to a decrease in the model bias to +3% over the ORV region. Over the contiguous US, the correlation coefficient (r between MDN observations and our IPR simulation increases from 0.63 to 0.78. The IPR nested simulation generally reproduces the seasonal cycle in surface concentrations of speciated Hg from the Atmospheric Mercury Network (AMNet and Canadian Atmospheric Mercury Network (CAMNet. In the IPR simulation, annual mean reactive gaseous and particulate-bound Hg are within 80% and 10% of observations, respectively. In contrast, the simulation with unmodified anthropogenic Hg speciation profiles overestimates these observations by factors of 2 to 4. The nested model shows improved skill at capturing the horizontal variability of Hg observed over California during the ARCTAS aircraft campaign. We find that North American anthropogenic emissions account for 10–22% of Hg wet

  9. Invasion of Asian tiger shrimp, Penaeus monodon Fabricius, 1798, in the western north Atlantic and Gulf of Mexico

    Science.gov (United States)

    Fuller, Pam L.; Knott, David M.; Kingsley-Smith, Peter R.; Morris, James A.; Buckel, Christine A.; Hunter, Margaret E.; Hartman, Leslie D.

    2014-01-01

    After going unreported in the northwestern Atlantic Ocean for 18 years (1988 to 2006), the Asian tiger shrimp, Penaeus monodon, has recently reappeared in the South Atlantic Bight and, for the first time ever, in the Gulf of Mexico. Potential vectors and sources of this recent invader include: 1) discharged ballast water from its native range in Asia or other areas where it has become established; 2) transport of larvae from established non-native populations in the Caribbean or South America via ocean currents; or 3) escape and subsequent migration from active aquaculture facilities in the western Atlantic. This paper documents recent collections of P. monodon from the South Atlantic Bight and the Gulf of Mexico, reporting demographic and preliminary phylogenetic information for specimens collected between North Carolina and Texas from 2006 through 2012. The increased number of reports in 2011 and 2012, ranging from 102 mm to 298 mm total length, indicates that an adult population is present in densities sufficient for breeding, which is indicative of incipient establishment. Based on these reports of P. monodon, its successful invasion elsewhere, and its life history, we believe that this species will become common in the South Atlantic Bight and Gulf of Mexico in less than 10 years. Penaeus monodon is an aggressive predator in its native range and, if established, may prey on native shrimps, crabs, and bivalves. The impacts of an established P. monodon population are potentially widespread (e.g., alterations in local commercial fisheries, direct and indirect pressures on native shrimp, crab and bivalve populations, and subsequent impacts on the populations of other predators of those organisms) and should be considered by resource managers. The impacts of P. monodon on native fauna and the source(s) or vector(s) of the invasion, however, remain unknown at this time.

  10. Prediction of interannual North Atlantic sea surface temperature and its remote influence over land

    Science.gov (United States)

    Lienert, Fabian; Doblas-Reyes, Francisco J.

    2016-07-01

    The quality of a multimodel of six coupled climate forecast systems initialized with observations—relative to the accompanying uninitialized system—to re-forecast the future annual-mean North Atlantic sea surface temperature (SST) departures is described. The study concludes that, measured by the anomaly correlation (AC) skill, the evolution of the leading two empirical orthogonal function modes of North Atlantic SSTs are skillfully forecast throughout the 9-year forecast range. This skill results in part from the predictions of the trend. The skill of the detrended modes, i.e., in absence of SST variability generated by the trend, is reduced, but still statistically distinguishable from zero throughout the 9-year forecast for the first mode and exclusively in the first two forecast years for the second mode. The initialization effect on the AC skill in the initialized system is statistically distinguishable from the one without initialization for the detrended first mode during the first three forecast years and the first forecast year only when the trend in North Atlantic SSTs is included. All six initialized systems of the multimodel are capable to skillfully forecast the shift of the full first mode of North Atlantic SST anomalies in the mid 1990s at all leads with HadCM 3 and EC-Earth 2.3 outperforming other systems. All systems share an intrinsic bias in simulating annual-mean SST variability in the North Atlantic. The study finds that the area-average AC skill (i.e., of a forecast containing regional information) of the North Atlantic influence on anomalous European temperature in the initialized multimodel is positive and statistically distinguishable from zero throughout the 9-year forecast for the full field case. On the other hand, a continent-wide forecast (i.e., without any regional information) of future European precipitation departures associated with North Atlantic SST variability is skillful throughout the 9-year forecast for the full field

  11. Vertical slab sinking and westward subduction offshore of Mesozoic North America

    Science.gov (United States)

    Sigloch, Karin; Mihalynuk, Mitchell G.

    2013-04-01

    Subducted slabs in the mantle, as imaged by seismic tomography, preserve a record of ancient subduction zones. Ongoing debate concerns how direct this link is. How long ago did each parcel of slab subduct, and where was the trench located relative to the imaged slab position? Resolving these questions will benefit paleogeographic reconstructions, and restrict the range of plausible rheologies for mantle convection simulations. We investigate one of the largest and best-constrained Mesozoic slab complexes, the "Farallon" in the transition zone and lower mantle beneath North America. We quantitatively integrate observations from whole-mantle P-wave tomography, global plate reconstructions, and land geological evidence from the North American Cordillera. These three data sets permit us to test the simplest conceivable hypothesis for linking slabs to paleo-trenches: that each parcel of slab sank only vertically shortly after entering the trench That is, we test whether within the limits of tomographic resolution, all slab material lies directly below the location where it subducted beneath its corresponding arc. Crucially and in contrast to previous studies, we do not accept or impose an Andean-style west coast trench (Farallon-beneath-continent subduction) since Jurassic times, as this scenario is inconsistent with many geological observations. Slab geometry alone suggests that trenches started out as intra-oceanic because tomography images massive, linear slab "walls" in the lower mantle, extending almost vertically from about 800 km to 2000+ km depth. Such steep geometries would be expected from slabs sinking vertically beneath trenches that were quasi-stationary over many tens of millions of years. Intra-oceanic trenches west of Mesozoic North America could have been stationary, whereas a coastal Farallon trench could not, because the continent moved westward continuously as the Atlantic opened. Overlap of North American west-coast positions, as reconstructed in a

  12. Impact of the North Atlantic sea surface temperature tripole on the East Asian summer monsoon

    Science.gov (United States)

    Zuo, Jinqing; Li, Weijing; Sun, Chenghu; Xu, Li; Ren, Hong-Li

    2013-07-01

    A strong (weak) East Asian summer monsoon (EASM) is usually concurrent with the tripole pattern of North Atlantic SST anomalies on the interannual timescale during summer, which has positive (negative) SST anomalies in the northwestern North Atlantic and negative (positive) SST anomalies in the subpolar and tropical ocean. The mechanisms responsible for this linkage are diagnosed in the present study. It is shown that a barotropic wave-train pattern occurring over the Atlantic-Eurasia region likely acts as a link between the EASM and the SST tripole during summer. This wave-train pattern is concurrent with geopotential height anomalies over the Ural Mountains, which has a substantial effect on the EASM. Diagnosis based on observations and linear dynamical model results reveals that the mechanism for maintaining the wave-train pattern involves both the anomalous diabatic heating and synoptic eddy-vorticity forcing. Since the North Atlantic SST tripole is closely coupled with the North Atlantic Oscillation (NAO), the relationships between these two factors and the EASM are also examined. It is found that the connection of the EASM with the summer SST tripole is sensitive to the meridional location of the tripole, which is characterized by large seasonal variations due to the north-south movement of the activity centers of the NAO. The SST tripole that has a strong relationship with the EASM appears to be closely coupled with the NAO in the previous spring rather than in the simultaneous summer.

  13. Atmospheric multidecadal variations in the North Atlantic realm: proxy data, observations, and atmospheric circulation model studies

    Directory of Open Access Journals (Sweden)

    K. Grosfeld

    2007-01-01

    Full Text Available We investigate the spatial and temporal characteristics of multidecadal climate variability in the North Atlantic realm, using observational data, proxy data and model results. The dominant pattern of multidecadal variability of SST depicts a monopolar structure in the North Atlantic during the instrumental period with cold (warm phases during 1900–1925 and 1970–1990 (1870–1890 and 1940–1960. Two atmospheric general circulation models of different complexity forced with global SST over the last century show SLP anomaly patterns from the warm and cold phases of the North Atlantic similar to the corresponding observed patterns. The analysis of a sediment core from Cariaco Basin, a coral record from the northern Red Sea, and a long-term sea level pressure (SLP reconstruction reveals that the multidecadal mode of the atmospheric circulation characterizes climate variability also in the pre-industrial era. The analyses of SLP reconstruction and proxy data depict a persistent atmospheric mode at least over the last 300 years, where SLP shows a dipolar structure in response to monopolar North Atlantic SST, in a similar way as the models' responses do. The combined analysis of observational and proxy data with model experiments provides an understanding of multidecadal climate modes during the late Holocene. The related patterns are useful for the interpretation of proxy data in the North Atlantic realm.

  14. Atmospheric multidecadal variations in the North Atlantic realm: proxy data, observations, and atmospheric circulation model studies

    Directory of Open Access Journals (Sweden)

    K. Grosfeld

    2006-08-01

    Full Text Available We investigate the spatial and temporal characteristics of multidecadal climate variability in the North Atlantic realm, using observational data, proxy data and model results. The dominant pattern of multidecadal variability of SST depicts a monopolar structure in the North Atlantic during the instrumental period with cold (warm phases during 1900–1925 and 1970–1990 (1870–1890 and 1940–1960. Two atmospheric general circulation models of different complexity forced with global SST over the last century show SLP anomaly patterns from the warm and cold phases of the North Atlantic similar to the corresponding observed patterns. The analysis of a sediment core from Cariaco Basin, a coral record from the northern Red Sea, and a long-term sea level pressure (SLP reconstruction reveals that the multidecadal mode of the atmospheric circulation characterizes climate variability also in the pre-industrial era. The analyses of SLP reconstruction and proxy data depict a persistent atmospheric mode at least over the last 300 years, where SLP shows a dipolar structure in response to monopolar North Atlantic SST, in a similar way as the models' responses do. The combined analysis of observational and proxy data with model experiments provides an understanding of multidecadal climate modes during the late Holocene. The related patterns are useful for the interpretation of proxy data in the North Atlantic realm.

  15. Statistical Aspects of Tropical Cyclone Activity in the North Atlantic Basin, 1945-2010

    Science.gov (United States)

    Wilson, Robert M.

    2012-01-01

    Examined are statistical aspects of the 715 tropical cyclones that formed in the North Atlantic basin during the interval 1945-2010. These 715 tropical cyclones include 306 storms that attained only tropical storm strength, 409 hurricanes, 179 major or intense hurricanes, and 108 storms that struck the US coastline as hurricanes. Comparisons made using 10-year moving average (10-yma) values between tropical cyclone parametric values and surface air and ENSO-related parametric values indicate strong correlations to exist, in particular, against the Armagh Observatory (Northern Ireland) surface air temperature, the Atlantic Multi-decadal Oscillation (AMO) index, the Atlantic Meridional Mode (AMM) index, and the North Atlantic Oscillation (NAO) index, in addition to the Oceanic Ni o index (ONI) and Quasi-Biennial Oscillation (QBO) indices. Also examined are the decadal variations of the tropical cyclone parametric values and a look ahead towards the 2012 hurricane season and beyond.

  16. Reduced North Atlantic deep water coeval with the glacial Lake Agassiz freshwater outburst.

    Science.gov (United States)

    Kleiven, Helga Kikki Flesche; Kissel, Catherine; Laj, Carlo; Ninnemann, Ulysses S; Richter, Thomas O; Cortijo, Elsa

    2008-01-01

    An outstanding climate anomaly 8200 years before the present (B.P.) in the North Atlantic is commonly postulated to be the result of weakened overturning circulation triggered by a freshwater outburst. New stable isotopic and sedimentological records from a northwest Atlantic sediment core reveal that the most prominent Holocene anomaly in bottom-water chemistry and flow speed in the deep limb of the Atlantic overturning circulation begins at approximately 8.38 thousand years B.P., coeval with the catastrophic drainage of Lake Agassiz. The influence of Lower North Atlantic Deep Water was strongly reduced at our site for approximately 100 years after the outburst, confirming the ocean's sensitivity to freshwater forcing. The similarities between the timing and duration of the pronounced deep circulation changes and regional climate anomalies support a causal link. PMID:18063758

  17. Kernel Density Estimation of Tropical Cyclone Frequencies in the North Atlantic Basin

    OpenAIRE

    Timothy A. Joyner; Robert V. Rohli

    2010-01-01

    Previous research has identified specific areas of frequent tropical cyclone activity in the North Atlantic basin. This study examines long-term and decadal spatio-temporal patterns of Atlantic tropical cyclone frequencies from 1944 to 2009, and analyzes categorical and decadal centroid patterns using kernel density estimation (KDE) and centrographic statistics. Results corroborate previous research which has suggested that the Bermuda-Azores anticyclone plays an integral role in the directio...

  18. Impact of tropical Pacific variability on the mean North Atlantic thermohaline circulation

    OpenAIRE

    Semenov, Vladimir; Latif, Mojib

    2006-01-01

    A series of 500 years long coupled general circulation model simulations has been performed, in which the sea surface temperatures (SSTs) in different tropical oceans have been prescribed from climatology. A statistically significant reduction by about one Sverdrup of the meridional overturning circulation (MOC) in the North Atlantic was found when the tropical Pacific SSTs do not vary interannually. Anomalously low salinities originating in the tropical Atlantic due to increased precipitatio...

  19. Seasonal forecasting of intense tropical cyclones over the North Atlantic and the western North Pacific basins

    Science.gov (United States)

    Choi, Woosuk; Ho, Chang-Hoi; Jin, Chun-Sil; Kim, Jinwon; Feng, Song; Park, Doo-Sun R.; Schemm, Jae-Kyung E.

    2016-02-01

    Intense tropical cyclones (TCs) accompanying torrential rain and powerful wind gusts often cause substantial socio-economic losses in the regions around their landfall. This study analyzes intense TCs in the North Atlantic (NA) and the western North Pacific (WNP) basins during the period 1982-2013. Different intensity criteria are used to define intense TCs for these two basins, category 1 and above for NA and category 3 and above for WNP, because the number of TCs in the NA basin is much smaller than that in the WNP basin. Using a fuzzy clustering method, intense TC tracks in the NA and the WNP basins are classified into two and three representative patterns, respectively. On the basis of the clustering results, a track-pattern-based model is then developed for forecasting the seasonal activities of intense TCs in the two basins. Cross-validation of the model skill for 1982-2013 as well as verification of a forecast for the 2014 TC season suggest that our intense TC model is applicable to operational uses.

  20. Age Dependent 3-D Magnetic Modeling of the North Pacific and North Atlantic Oceanic Crust at Intermediate Wavelengths

    Science.gov (United States)

    Yanez, Gonzalo A.; LaBrecque, John L.

    1996-01-01

    Three-dimensional magnetic modeling of the North Atlantic and Northeast pacific is performed at intermediate wavelengths using three models for the acquisition of a natural remanent magnetization. It is shown that a remanent magnetization which is dependent on the rustal age is the dominant source for the intermediate wavelength pattern in both basins.

  1. Uranium production capability: North America, Australia, Asia and Africa

    International Nuclear Information System (INIS)

    With the apparent need for additional primary uranium supply, the paper discusses necessary preconditions for mine construction and then reviews the supply potential in North America, Australia, Africa and Asia. Canadian uranium supply will increase from 12 000 t U to over 16 000 t U by 2011 with the commencement of production at the Cigar Lake mine and the eventual mining of the Midwest Lake deposit. Canadian production levels will then begin a slow and steady decline from 2014 onwards as existing economic deposits become exhausted. Production in the United States of America will continue to be dominated by in situ leech mines but certain conventional mines will provide some additional production. Total US production may reach 4000 t U by 2010. Future Australian production levels are clouded in uncertainty. Restrictive Government policies are once again having an impact on uranium prices. A potential tripling of production at Olympic Dam, however, will have a dramatic impact on uranium supplies if a decision to expand production is indeed made. Depending upon market forces, Government and corporate decisions, uranium production in Australia could vary from as little as 4500 t U to as much as 22 000 t U by 2020. After 30 years of production, Phase 1 mining at the Roessing mine in Namibia is nearly complete and the mine is now faced with a series of difficult decisions in order to remain in operation beyond 2009. Steady output from existing mines in Niger is expected for at least a further ten years, and additional mining opportunities have been identified. Other potential African production sources are also discussed. Mongolia has the potential to become a new modest sized producer, depending upon the outcome of further studies. Production levels in India and China are expected to increase modestly in order to help satisfy domestic needs. (author)

  2. Intensified impact of tropical Atlantic SST on the western North Pacific summer climate under a weakened Atlantic thermohaline circulation

    Science.gov (United States)

    Chen, Wei; Lee, June-Yi; Lu, Riyu; Dong, Buwen; Ha, Kyung-Ja

    2015-10-01

    The tropical North Atlantic (TNA) sea surface temperature (SST) has been identified as one of regulators on the boreal summer climate over the western North Pacific (WNP), in addition to SSTs in the tropical Pacific and Indian Oceans. The major physical process proposed is that the TNA warming induces a pair of cyclonic circulation anomaly over the eastern Pacific and negative precipitation anomalies over the eastern to central tropical Pacific, which in turn lead to an anticyclonic circulation anomaly over the western to central North Pacific. This study further demonstrates that the modulation of the TNA warming to the WNP summer climate anomaly tends to be intensified under background of the weakened Atlantic thermohaline circulation (THC) by using a water-hosing experiment. The results suggest that the weakened THC induces a decrease in thermocline depth over the TNA region, resulting in the enhanced sensitivity of SST variability to wind anomalies and thus intensification of the interannual variation of TNA SST. Under the weakened THC, the atmospheric responses to the TNA warming are westward shifted, enhancing the anticyclonic circulation and negative precipitation anomaly over the WNP. This study supports the recent finding that the negative phase of the Atlantic multidecadal oscillation after the late 1960s has been favourable for the strengthening of the connection between TNA SST variability and WNP summer climate and has important implications for seasonal prediction and future projection of the WNP summer climate.

  3. Free troposphere ozone and carbon monoxide over the North Atlantic for 2001–2011

    Directory of Open Access Journals (Sweden)

    A. Kumar

    2013-06-01

    Full Text Available In-situ measurements of carbon monoxide (CO and ozone (O3 at the Pico Mountain Observatory (PMO located in the Azores, Portugal are analyzed together with results from atmospheric chemical transport modeling (GEOS-Chem and satellite remote sensing (AIRS for CO and TES for O3 to examine the evolution of free-troposphere CO and O3 over the North Atlantic for 2001–2011. GEOS-Chem captured the seasonal cycles for CO and O3 well but significantly underestimated the mixing ratios of CO, particularly in spring. Statistically significant (using a significance level of 0.05 decreasing trends were found for both CO and O3 based on harmonic regression analysis of the measurement data. The best estimates of the trend for CO and O3 measurements are −0.31 ± 0.30 (2-σ ppbv yr−1 and −0.21 ± 0.11 (2-σ ppbv yr−1, respectively. Similar decreasing trends for both species were obtained with GEOS-Chem simulation results. The major factor contributing to the reported decrease in CO and O3 mixing ratios at PMO over the past decade is the decline in anthropogenic CO and O3-precursor emissions in regions such as North America and Europe. The increase in Asian emissions does not seem to outweigh the impact of these declines resulting in overall decreasing trends for both CO and O3. For O3, however, increase in atmospheric water vapor content associated with climate change also appears to be a contributing factor causing enhanced destruction of the O3 during transport from source regions. These hypotheses are supported by results from the GEOS-Chem tagged CO and tagged O3 simulations.

  4. Pan-Continental Droughts in North America over the Last Millennium

    Science.gov (United States)

    Cook, Benjamin I.; Smerdon, Jason E.; Seager, Richard; Cook, Edward R.

    2014-01-01

    Regional droughts are common in North America, but pan-continental droughts extending across multiple regions, including the 2012 event, are rare relative to single-region events. Here, the tree-ring-derived North American Drought Atlas is used to investigate drought variability in four regions over the last millennium, focusing on pan-continental droughts. During the Medieval Climate Anomaly (MCA), the central plains (CP), Southwest (SW), and Southeast (SE) regions experienced drier conditions and increased occurrence of droughts and the Northwest (NW) experienced several extended pluvials. Enhanced MCA aridity in the SW and CP manifested as multidecadal megadroughts. Notably, megadroughts in these regions differed in their timing and persistence, suggesting that they represent regional events influenced by local dynamics rather than a unified, continental-scale phenomena. There is no trend in pan-continental drought occurrence, defined as synchronous droughts in three or more regions. SW, CP, and SE (SW+CP+SE) droughts are the most common, occurring in 12 percent of all years and peaking in prevalence during the twelfth and thirteenth centuries; patterns involving three other regions occur in about 8 percent of years. Positive values of the Southern Oscillation index (La Nina conditions) are linked to SW, CP, and SE (SW+CP+SE) droughts and SW, CP, and NW (SW+CP+NW) droughts, whereas CP, NW, and SE (CP+NW+SE) droughts are associated with positive values of the Pacific decadal oscillation and Atlantic multidecadal oscillation. While relatively rare, pan-continental droughts are present in the paleo record and are linked to defined modes of climate variability, implying the potential for seasonal predictability. Assuming stable drought teleconnections, these events will remain an important feature of future North American hydroclimate, possibly increasing in their severity in step with other expected hydroclimate responses to increased greenhouse gas forcing.

  5. Variability of Fram Strait Ice Flux and North Atlantic Oscillation

    Science.gov (United States)

    Kwok, Ron

    1999-01-01

    An important term in the mass balance of the Arctic Ocean sea ice is the ice export. We estimated the winter sea ice export through the Fram Strait using ice motion from satellite passive microwave data and ice thickness data from moored upward looking sonars. The average winter area flux over the 18-year record (1978-1996) is 670,000 square km, approximately 7% of the area of the Arctic Ocean. The winter area flux ranges from a minimum of 450,000 sq. km in 1984 to a maximum of 906,000 sq km in 1995. The daily, monthly and interannual variabilities of the ice area flux are high. There is an upward trend in the ice area flux over the 18-year record. The average winter volume flux over the winters of October 1990 through May 1995 is 1745 cubic km ranging from a low of 1375 cubic km in 1990 to a high of 2791 cubic km in 1994. The sea-level pressure gradient across the Fram Strait explains more than 80% of the variance in the ice flux over the 18-year record. We use the coefficients from the regression of the time-series of area flux versus pressure gradient across the Fram Strait and ice thickness data to estimate the summer area and volume flux. The average 12-month area flux and volume flux are 919,000 sq km and 2366 cubic km. We find a significant correlation (R =0.86) between the area flux and positive phases of the North Atlantic Oscillation (NAO) index over the months of December through March. Correlation between our six years of volume flux estimates and the NAO index gives R =0.56. During the high NAO years, a more intense Icelandic low increases the gradient in the sea-level pressure by almost 1 mbar across the Fram Strait thus increasing the atmospheric forcing on ice transport. Correlation is reduced during the negative NAO years because of decreased dominance of this large-scale atmospheric pattern on the sea-level pressure gradient across the Fram Strait. Additional information is contained in the original.

  6. Glacier response to North Atlantic climate variability during the Holocene

    Directory of Open Access Journals (Sweden)

    N. L. Balascio

    2015-05-01

    Full Text Available Small glaciers and ice caps respond rapidly to climate variations and records of their past extent provide information on the natural envelope of past climate variability. Millennial-scale trends in Holocene glacier size are well documented and correspond with changes in Northern Hemisphere summer insolation. However, there is only sparse and fragmentary evidence for higher frequency variations in glacier size because in many Northern Hemisphere regions glacier advances of the past few hundred years were the most extensive and destroyed the geomorphic evidence of ice growth and retreat during the past several thousand years. Thus, most glacier records have been of limited use for investigating centennial scale climate forcing and feedback mechanisms. Here we report a continuous record of glacier activity for the last 9.5 ka from southeast Greenland, derived from high-resolution measurements on a proglacial lake sediment sequence. Physical and geochemical parameters show that the glaciers responded to previously documented Northern Hemisphere climatic excursions, including the "8.2 ka" cooling event, the Holocene Thermal Maximum, Neoglacial cooling, and 20th Century warming. In addition, the sediments indicate centennial-scale oscillations in glacier size during the late Holocene. Beginning at 4.1 ka, a series of abrupt glacier advances occurred, each lasting ~100 years and followed by a period of retreat, that were superimposed on a gradual trend toward larger glacier size. Thus, while declining summer insolation caused long-term cooling and glacier expansions during the late Holocene, climate system dynamics resulted in repeated episodes of glacier expansion and retreat on multi-decadal to centennial timescales. These episodes coincided with ice rafting events in the North Atlantic Ocean and periods of regional ice cap expansion, which confirms their regional significance and indicates that considerable glacier activity on these timescales is a

  7. Oceanic dominance of interannual subtropical North Atlantic heat content variability

    Directory of Open Access Journals (Sweden)

    M. Sonnewald

    2013-01-01

    Full Text Available Ocean heat content varies on a range of timescales. Traditionally the atmosphere is seen to dominate the oceanic heat content variability. However, this variability can be driven either by oceanic or atmospheric heat fluxes. To diagnose the relative contributions and respective timescales, this study uses a box model forced with output from an ocean general circulation model (OGCM to investigate the heat content variability of the upper 800 m of the subtropical North Atlantic from 26° N to 36° N. The ocean and air-sea heat flux data needed to force the box model is taken from a 19 yr (1988 to 2006 simulation performed with the 1/12° version of the OCCAM OGCM. The box model heat content is compared to the corresponding heat content in OCCAM for verification. The main goal of the study is to identify to what extent the seasonal to interannual ocean heat content variability is of atmospheric or oceanic origin. To this end, the box model is subjected to a range of scenarios forced either with the full (detrended ocean and air-sea fluxes, or their deseasoned counterparts. Results show that in all cases, the seasonal variability is dominated by the seasonal component of the air-sea fluxes, which produce a seasonal range in mean temperature of the upper 800 m of ~ 0.42 °C. However, on longer timescales oceanic heat transport dominates, with changes of up to ~ 0.30 °C over 4 yr.

    The technique is subsequently applied to observational data. For the ocean heat fluxes, we use data from the RAPID program at 26° N from April 2004 to January 2011. At 36° N heat transport is inferred using a linear regression model based on the oceanic low-frequency transport in OCCAM. The air-sea flux from OCCAM is used for the period 2004 to 2006 when the RAPID timeseries and the OCCAM simulation overlap, and a climatology is used for the air-sea flux from 2006 onwards. The results confirm that on longer (> 2 yr timescales the ocean dominates the ocean heat

  8. The atmospheric response over the North Atlantic decadal changes in sea surface temperature

    Energy Technology Data Exchange (ETDEWEB)

    Venzke, S. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Allen, M.R. [Rutherford Appleton Lab., Chilton (United Kingdom). Dept. of Space Sciences]|[Oxford Univ. (United Kingdom). Atmospheric, Oceanic and Planetary Physics; Sutton, R.T. [Oxford Univ. (United Kingdom). Atmospheric, Oceanic and Planetary Physics]|[Reading Univ. (United Kingdom). Dept. of Meteorology; Rowell, D.P. [Hadley Centre for Climate Prediction and Research, Bracknell (United Kingdom). Meteorological Office

    1998-05-04

    Decadal fluctuations in the climate of the North Atlantic/European region may be influenced by interactions between the atmosphere and the Atlantic ocean, possibly as part of a coupled ocean-atmosphere mode of variability. For such a mode to exist, a consistent atmospheric response to fluctuations in North Atlantic sea surface temperatures (SST) is required. Furthermore, this response must provide feedbacks to the ocean. Whether a consistent response exists, and whether it yields the required feedbacks, are issues that remain controversial. We address these issues using a novel approach to analyse an ensemble of six integrations of the Hadley Centre atmospheric general circulation model (HadAM1), all forced with observed SST and sea-ice extents for the period 1949-93. Characterising the forced atmospheric response is complicated by the presence of internal variability. We use a generalisation of principal component analysis to estimate the common forced response given the knowledge of internal variability provided by the ensemble. In the North Atlantic we identify a remote atmospheric response to El Ni no / southern oscillation (ENSO) and a further response related to a tripole pattern in North Atlantic SST. The latter, which is most consistent in spring, involves atmospheric circulation changes over the entire region, including a dipole pattern in sea level pressure often associated with the North Atlantic oscillation (NAO). Only over the tropical/subtropical Atlantic, however, does it account for a substantial fraction of the total variance. We investigate how the atmospheric response could feed back to affect the ocean, and in particular the SST tripole. 46 refs.

  9. A Review of ENSO Influence on the North Atlantic. A Non-Stationary Signal

    Directory of Open Access Journals (Sweden)

    Belén Rodríguez-Fonseca

    2016-06-01

    Full Text Available The atmospheric seasonal cycle of the North Atlantic region is dominated by meridional movements of the circulation systems: from the tropics, where the West African Monsoon and extreme tropical weather events take place, to the extratropics, where the circulation is dominated by seasonal changes in the jetstream and extratropical cyclones. Climate variability over the North Atlantic is controlled by various mechanisms. Atmospheric internal variability plays a crucial role in the mid-latitudes. However, El Niño-Southern Oscillation (ENSO is still the main source of predictability in this region situated far away from the Pacific. Although the ENSO influence over tropical and extra-tropical areas is related to different physical mechanisms, in both regions this teleconnection seems to be non-stationary in time and modulated by multidecadal changes of the mean flow. Nowadays, long observational records (greater than 100 years and modeling projects (e.g., CMIP permit detecting non-stationarities in the influence of ENSO over the Atlantic basin, and further analyzing its potential mechanisms. The present article reviews the ENSO influence over the Atlantic region, paying special attention to the stability of this teleconnection over time and the possible modulators. Evidence is given that the ENSO–Atlantic teleconnection is weak over the North Atlantic. In this regard, the multidecadal ocean variability seems to modulate the presence of teleconnections, which can lead to important impacts of ENSO and to open windows of opportunity for seasonal predictability.

  10. Depth Profiles of Persistent Organic Pollutants in the North and Tropical Atlantic Ocean.

    Science.gov (United States)

    Sun, Caoxin; Soltwedel, Thomas; Bauerfeind, Eduard; Adelman, Dave A; Lohmann, Rainer

    2016-06-21

    Little is known of the distribution of persistent organic pollutants (POPs) in the deep ocean. Polyethylene passive samplers were used to detect the vertical distribution of truly dissolved POPs at two sites in the Atlantic Ocean. Samplers were deployed at five depths covering 26-2535 m in the northern Atlantic and Tropical Atlantic, in approximately one year deployments. Samplers of different thickness were used to determine the state of equilibrium POPs reached in the passive samplers. Concentrations of POPs detected in the North Atlantic near the surface (e.g., sum of 14 polychlorinated biphenyls, PCBs: 0.84 pg L(-1)) were similar to previous measurements. At both sites, PCB concentrations showed subsurface maxima (tropical Atlantic Ocean -800 m, North Atlantic -500 m). Currents seemed more important in moving POPs to deeper water masses than the biological pump. The ratio of PCB concentrations in near surface waters (excluding PCB-28) between the two sites was inversely correlated with congeners' subcooled liquid vapor pressure, in support of the latitudinal fractionation. The results presented here implied a significant amount of HCB is stored in the Atlantic Ocean (4.8-26% of the global HCB environmental burdens), contrasting traditional beliefs that POPs do not reach the deep ocean. PMID:27174500

  11. Predicting Pleistocene climate from vegetation in North America

    Science.gov (United States)

    Loehle, C.

    2007-02-01

    Climates at the Last Glacial Maximum have been inferred from fossil pollen assemblages, but these inferred climates are colder for eastern North America than those produced by climate simulations. It has been suggested that low CO2 levels could account for this discrepancy. In this study biogeographic evidence is used to test the CO2 effect model. The recolonization of glaciated zones in eastern North America following the last ice age produced distinct biogeographic patterns. It has been assumed that a wide zone south of the ice was tundra or boreal parkland (Boreal-Parkland Zone or BPZ), which would have been recolonized from southern refugia as the ice melted, but the patterns in this zone differ from those in the glaciated zone, which creates a major biogeographic anomaly. In the glacial zone, there are few endemics but in the BPZ there are many across multiple taxa. In the glacial zone, there are the expected gradients of genetic diversity with distance from the ice-free zone, but no evidence of this is found in the BPZ. Many races and related species exist in the BPZ which would have merged or hybridized if confined to the same refugia. Evidence for distinct southern refugia for most temperate species is lacking. Extinctions of temperate flora were rare. The interpretation of spruce as a boreal climate indicator may be mistaken over much of the region if the spruce was actually an extinct temperate species. All of these anomalies call into question the concept that climates in the zone south of the ice were extremely cold or that temperate species had to migrate far to the south. An alternate hypothesis is that low CO2 levels gave an advantage to pine and spruce, which are the dominant trees in the BPZ, and to herbaceous species over trees, which also fits the observed pattern. Thus climate reconstruction from pollen data is probably biased and needs to incorporate CO2 effects. Most temperate species could have survived across their current ranges at lower

  12. Status of woodland caribou in western north America

    Directory of Open Access Journals (Sweden)

    E. Janet Edmonds

    1991-10-01

    Full Text Available A review of current population size and trends of woodland caribou (Rangifer tarandus caribou in seven jurisdictions in western North America shows a wide range of situations. A total maximum population estimate of woodland caribou west of the Ontario/Manitoba border is 61 090. Of 44 herds or populations described in this review: 14 are stable; two are stable to slightly decreasing; four are decreasing; four are increasing; and 22 are of unknown status. Caribou are classified as a threatened species in Alberta and as an endangered species in Washington/Idaho. The decline of caribou in North America following settlement (Bergerud, 1974 has continued along the southern edge of woodland caribou distribution. Direct loss of habitat to logging, mines and dams continued throughout the I960s, 1970s and 1980s. The secondary effects of these habitat changes, (i.e. increased roads leading to increased hunting and poaching, and increased early succession habitat leading to increased alternate prey/predator densities has led in some cases to the total loss or decreased size of local herds. Three ecotypes of woodland caribou are described and their relative distribution delineated. These ecotypes live under different environmental conditions and require different inventory and management approaches. Woodland caribou herds in northern B.C., Yukon and N.W.T. generally are of good numbers and viable (stable or increasing, and management primarily is directed at regulating human harvest and natural predation to prevent, herd declines. Land use activities such as logging or energy development are not extensive. Managers in southern caribou ranges stress the need for a better understanding of caribou population stability within mixed prey/predator regimes; how habitat changes (eg. through logging affect these regimes; and how to develop effective land use guidelines for resource extraction that can sustian caribou populations and maintain resource industries

  13. Magnitude and Carbon Consequences of Forest Management in North America

    Science.gov (United States)

    Masek, J.; Kurz, W.; de Jong, B. H.

    2009-12-01

    The carbon balance of forests depends on the type, frequency and severity of recent disturbances (carbon source) and the rate of recovery from past disturbance (carbon sink). Harvest and land cover conversion represent significant forest disturbance agents over much of North America. For example, pine forests in the southeastern US are typically harvested at ~20 year intervals, and may occupy about half the regional landscape, resulting in regional landscape turnover rates of 2-3% per year. Inventory data are the primary source for quantifying information on harvest and conversion in the U.S., Mexico, and Canada. Recent inventory data from these countries indicate timber production of 424 million cu m, 163 million cu m, and 7 million cu m, respectively, with significant year-to-year variability associated with wood products demand and timber price. Areas affected by harvest activity vary as well, with 3.97 Mha (million hectares) and 1.04 Mha affected by harvest in the US and Canada, respectively. Forest cover conversion (deforestation) is thought to be relatively minor in the US and Canada, but recent estimates suggest that forest and woodland cover in Mexico declined by 300-500 Kha/yr during the 1990’s. Recently, satellite remote sensing data products on forest change have been generated that complement the traditional inventory approach. These products are particularly useful for “wall-to-wall” estimates of forest conversion and tracking small disturbances. The type and severity of disturbance cannot be easily determined using satellite observations, however, and therefore some care must be taken to reconcile these products with ground-based data. In this talk we review available resources for characterizing “carbon relevant” information on the magnitude (area, type of activity) of forest management in North America, and attempt a first-order comparison between remote sensing and inventory estimates. We also discuss strategies that might be employed to

  14. Statistical Aspects of the North Atlantic Basin Tropical Cyclones: Trends, Natural Variability, and Global Warming

    Science.gov (United States)

    Wilson, Robert M.

    2007-01-01

    Statistical aspects of the North Atlantic basin tropical cyclones for the interval 1945- 2005 are examined, including the variation of the yearly frequency of occurrence for various subgroups of storms (all tropical cyclones, hurricanes, major hurricanes, U.S. landfalling hurricanes, and category 4/5 hurricanes); the yearly variation of the mean latitude and longitude (genesis location) of all tropical cyclones and hurricanes; and the yearly variation of the mean peak wind speeds, lowest pressures, and durations for all tropical cyclones, hurricanes, and major hurricanes. Also examined is the relationship between inferred trends found in the North Atlantic basin tropical cyclonic activity and natural variability and global warming, the latter described using surface air temperatures from the Armagh Observatory Armagh, Northern Ireland. Lastly, a simple statistical technique is employed to ascertain the expected level of North Atlantic basin tropical cyclonic activity for the upcoming 2007 season.

  15. Linkage Between Mei-yu Precipitation and North Atlantic SST on the Decadal Timescale

    Institute of Scientific and Technical Information of China (English)

    GU Wei; LI Chongyin; WANG Xin; ZHOU Wen; LI Weijing

    2009-01-01

    This paper investigates the relationship between mei-yu and North Atlantic sea surface temperature anomalies (SSTA). Results show that they are significantly associated with each other on the decadal timescale. Both mei-yu precipitation and mei-yu duration are characterized by significant decadal variability. Their decadal components are closely correlated with a triple mode of North Atlantic SSTA in the preceding winter. Regression analysis demonstrates that the wintertime North Atlantic SSTA may impose a delayed impact on East Asia Summer Monsoon (EASM) circulation and mei-yu on the decadal timescale. The persistency of SSTA plays an important role during this course. The triple SSTA mode can persist from winter until late spring. It is suggested that the springtime SSTA may excite a stationary wave-train propagating from west Eurasia to East Asia and exert an impact on mei-yu.

  16. Probable changes in lake chemistry in Canada’s Atlantic Provinces under proposed North American emission reductions

    Directory of Open Access Journals (Sweden)

    T. A. Clair

    2003-01-01

    Full Text Available Atlantic Canada, located in the extreme north-eastern portion of North America, receives acid precipitation from all major acid emission sources on the eastern part of the continent. The region was glaciated and has thin soils over a generally poorly acid buffering bedrock. Because of regional topography, large groupings of lakes occur in a number of regions. Environment Canada and the Government of New Brunswick have operated lake sampling networks in trend detection studies and have concentrated their work on these lake groupings. The MAGIC model has been applied to these lakes and their catchments to see: a what initial water chemistry conditions existed before acidification began, b what the chemistry was like during the worst of regional acid deposition, and c what it would be like under deposition conditions predicted for new Canadian and US emission reduction proposals. While pH, sulphate, acid neutralisation capacity (ANC and the sum of the base cations (SBC of all lakes have been significantly affected by acid deposition, water chemistry conditions are now considerably better than they were in 1975, at the worst of the deposition. However, a 50% reduction in acid deposition from Year 2000 deposition amounts will not return water chemistry to original conditions in most of the region. Keywords: Atlantic Canada, monitoring networks, acidification, predictions, MAGIC

  17. Gamma radiation monitoring at the Eastern North Atlantic (ENA), Graciosa Island ARM facility

    Science.gov (United States)

    Barbosa, Susana; Miranda, Pedro; Azevedo, Eduardo B.; Nitschke, Kim

    2016-04-01

    Continuous monitoring of gamma radiation is often performed in nuclear facilities and industrial environments as a way to control the ambient radioactivity and give warning of potential accidents. However, gamma radiation is also ubiquitous in the natural environment. The main sources are i) cosmic radiation from space, including secondary radiation from the interaction with atoms in the atmosphere, ii) terrestrial sources from mineral grains in soils and rocks, particularly Potassium (K-40), Uranium (U-238) and Thorium (Th-232) and their decay products (e.g. Radium, Ra-226) , and iii) airborne Radon gas (Rn-222), which is the dominant source of natural environmental radioactivity. The temporal variability of this natural radiation background needs to be well understood and quantified in order to discriminate non-natural sources of radiation in the environment and artificial radionuclides contamination. To this end, continuous gamma radiation monitoring is being performed at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM), established and supported by the Department of Energy (DOE) of the United States of America with the collaboration of the local government and University of the Azores. The site is unique for the study of the natural radioactivity background on one hand due to the remote oceanic geographical location, in the middle of the North Atlantic Ocean and clear of direct continental influence, and on the other hand because of the comprehensive dataset of atmospheric parameters that is available for enhancing the interpretation of the radiation measurements, as a result of the vast array of very detailed and high-quality atmospheric measurements performed at the ARM-ENA facility. Gamma radiation in the range 475 KeV to 3000 KeV is measured continuously with a 3" x 3" NaI(Tl) scintillator. The campaign started started in May 2015, with gamma

  18. Climate directly influences Eocene mammal faunal dynamics in North America.

    Science.gov (United States)

    Woodburne, Michael O; Gunnell, Gregg F; Stucky, Richard K

    2009-08-11

    The modern effect of climate on plants and animals is well documented. Some have cautioned against assigning climate a direct role in Cenozoic land mammal faunal changes. We illustrate 3 episodes of significant mammalian reorganization in the Eocene of North America that are considered direct responses to dramatic climatic events. The first episode occurred during the Paleocene-Eocene Thermal Maximum (PETM), beginning the Eocene (55.8 Ma), and earliest Wasatchian North American Land Mammal Age (NALMA). The PETM documents a short (<170 k.y.) global temperature increase of approximately 5 degrees C and a substantial increase in first appearances of mammals traced to climate-induced immigration. A 4-m.y. period of climatic and evolutionary stasis then ensued. The second climate episode, the late early Eocene Climatic Optimum (EECO, 53-50 Ma), is marked by a temperature increase to the highest prolonged Cenozoic ocean temperature and a similarly distinctive continental interior mean annual temperature (MAT) of 23 degrees C. This MAT increase [and of mean annual precipitation (MAP) to 150 cm/y) promoted a major increase in floral diversity and habitat complexity under temporally unique, moist, paratropical conditions. Subsequent climatic deterioration in a third interval, from 50 to 47 Ma, resulted in major faunal diversity loss at both continental and local scales. In this Bridgerian Crash, relative abundance shifted from very diverse, evenly represented, communities to those dominated by the condylarth Hyopsodus. Rather than being "optimum," the EECO began the greatest episode of faunal turnover of the first 15 m.y. of the Cenozoic. PMID:19666605

  19. Links between tropical rainfall and North Atlantic climate during the last glacial period

    Science.gov (United States)

    Deplazes, Gaudenz; Lückge, Andreas; Peterson, Larry C.; Timmermann, Axel; Hamann, Yvonne; Hughen, Konrad A.; Röhl, Ursula; Laj, Carlo; Cane, Mark A.; Sigman, Daniel M.; Haug, Gerald H.

    2013-03-01

    During the last glacial period, the North Atlantic regionexperienced pronounced, millennial-scale alternations between cold, stadial conditions and milder interstadial conditions--commonly referred to as Dansgaard-Oeschger oscillations--as well as periods of massive iceberg discharge known as Heinrich events. Changes in Northern Hemisphere temperature, as recorded in Greenland, are thought to have affected the location of the Atlantic intertropical convergence zone and the strength of the Indian summer monsoon. Here we use high-resolution records of sediment colour--a measure of terrigenous versus biogenic content--from the Cariaco Basin off the coast of Venezuela and the Arabian Sea to assess teleconnections with the North Atlantic climate system during the last glacial period. The Cariaco record indicates that the intertropical convergence zone migrated seasonally over the site during mild stadial conditions, but was permanently displaced south of the basin during peak stadials and Heinrich events. In the Arabian Sea, we find evidence of a weak Indian summer monsoon during the stadial events. The tropical records show a more variable response to North Atlantic cooling than the Greenland temperature records. We therefore suggest that Greenland climate is especially sensitive to variations in the North Atlantic system--in particular sea-ice extent--whereas the intertropical convergence zone and Indian monsoon system respond primarily to variations in mean Northern Hemisphere temperature.

  20. Bacterial and archaeal dynamics in phylogeny and function in the North Atlantic deep waters

    Science.gov (United States)

    Herndl, G. J.; Brink, M.; Agogue, H.

    2009-04-01

    The diversity and specific functional aspects linked to the N cycle of the bacterio- and archaeoplankton were investigated in the major deep water masses of the North Atlantic following the main driver of the thermohaline circulation, the North Atlantic Deep Water, from 65°N to 5°S. The phylogenetic composition of Bacteria and Archaea is not only depth-dependent but, specific water masses harbor specific prokaryotic communities. The specific composition of these communities in a particular water mass is maintained even over large distances. The distribution of archaeal and bacterial amoA genes were also determined. Archaeal amoA copy numbers decreased drastically with depth especially in the eastern subtropical Atlantic. This coincides with the lower nutrient concentration of the deep waters in the southern parts of the North Atlantic and the older age of the deep-water masses there. These data demonstrate that the diversity and potential nitrification activity are closely linked to the hydrology and chemical characteristics of the major water masses in the North Atlantic.

  1. EProjected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

    OpenAIRE

    M. Gehlen; Seferian, R.; Jones, D.O.B.; Roy, Tilla; R. Roth; Barry, J.; L. Bopp; Doney, S. C.; Dunne, J.P.; C. Heinze; Joos, F.; Orr, J.C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

    2014-01-01

    This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500m depth in the North Atlantic sector will experience pH reduc...

  2. Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

    OpenAIRE

    M. Gehlen; Séférian, R.; Jones, D.O.B.; Roy, T; R. Roth; Barry, J.; L. Bopp; Doney, S. C.; Dunne, J.P.; C. Heinze; Joos, F.; Orr, J.C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

    2014-01-01

    This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will experience pH redu...

  3. Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

    OpenAIRE

    M. Gehlen; Séférian, R.; Jones, D.O.B.; Roy, T; R. Roth; Barry, J.; L. Bopp; Doney, S. C.; Dunne, J.P.; C. Heinze; Joos, F.; Orr, J.C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

    2014-01-01

    This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will ...

  4. Synoptic-scale analysis of mechanisms driving surface chlorophyll dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Hatun, H.; Counillon, F.; Payne, Mark; Visser, Andre

    2015-01-01

    show that, in terms of bottom-up processes alone, there is a dominant physical mechanism, namely mixed-layer shoaling, that best predicts the interannual variation in the initial increase in surface chlorophyll across large sectors of the North Atlantic. We further show that different regions are...... governed by different physical phenomena and that wind-driven mixing is a common component, with either heat flux or light as triggers. We believe these findings to be relevant to the ongoing discussion on North Atlantic bloom onset....

  5. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns

    Science.gov (United States)

    Wilson, Robert M.

    2009-01-01

    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  6. Distributional shifts of species in the North Atlantic: the rule or the exception?

    DEFF Research Database (Denmark)

    Payne, Mark

    This work addresses recent shifts in the distribution of marine pelagic fish in the northern North Atlantic and attempts to set them in the context of climate variability, climate change, population dynamics and migration processes. Shifts in the distribution of North-east Atlantic mackerel, and...... presented and discussed here. These examples are then used to illustrate the potential importance of various mechanisms that can control the distribution of these species, such as climate variability and change, and population and migration dynamics. A set of simple analytical approaches is demonstrated...

  7. Perchlorate and nitrate in leafy vegetables of North America.

    Science.gov (United States)

    Sanchez, C A; Crump, K S; Krieger, R I; Khandaker, N R; Gibbs, J P

    2005-12-15

    In previous studies trace levels of perchlorate were found in lettuce (Lactuca sativa L.) irrigated with Colorado River water, which is contaminated with low levels of perchlorate from aerospace and defense related industries. In this paper, we report the results of a survey conducted across North America to evaluate the occurrence of perchlorate in leafy vegetables produced outside the lower Colorado River region, and evaluate the relative iodide uptake inhibition potential to perchlorate and nitrate in these leafy vegetables. Conventionally and organically produced lettuce and other leafy vegetable samples were collected from production fields and farmers' markets in the central and coastal valleys of California, New Mexico, Colorado, Michigan, Ohio, New York, Quebec, and New Jersey. Results show that 16% of the conventionally produced samples and 32% of the organically produced samples had quantifiable levels of perchlorate using ion chromatography. Estimated perchlorate exposure from organically produced leafy vegetables was approximately 2 times that of conventional produce, but generally less than 10% of the reference dose recommended by the National Academy of Sciences. Furthermore, the iodide uptake inhibition potential of perchlorate was less than 1% of that of the nitrate present. These data are consistent with those of other reported perchlorate survey work with lettuce, bottled water, breast milk, dairy milk, and human urine, and suggest a wide national presence of perchlorate. PMID:16475313

  8. Can coyotes affect deer populations in Southeastern North America?

    Energy Technology Data Exchange (ETDEWEB)

    Kilgo, J., C.; Ray, H., Scott; Ruth, Charles; Miller, Karl, V.

    2010-07-01

    ABSTRACT The coyote (Canis latrans) is a recent addition to the fauna of eastern North America, and in many areas coyote populations have been established for only a decade or two. Although coyotes are known predators of white-tailed deer (Odocoileus virginianus) in their historic range, effects this new predator may have on eastern deer populations have received little attention. We speculated that in the southeastern United States, coyotes may be affecting deer recruitment, and we present 5 lines of evidence that suggest this possibility. First, the statewide deer population in South Carolina has declined coincident with the establishment and increase in the coyote population. Second, data sets from the Savannah River Site (SRS) in South Carolina indicate a new mortality source affecting the deer population concurrent with the increase in coyotes. Third, an index of deer recruitment at SRS declined during the period of increase in coyotes. Fourth, food habits data from SRS indicate that fawns are an important food item for coyotes during summer. Finally, recent research from Alabama documented significant coyote predation on fawns there. Although this evidence does not establish cause and effect between coyotes and observed declines in deer recruitment, we argue that additional research should proactively address this topic in the region. We identified several important questions on the nature of the deer–coyote relationship in the East.

  9. In the spotlight: New hydro development in North America

    International Nuclear Information System (INIS)

    1992 was a year of progress for many segments of the hydropower industry as developers worked to bring new projects on line. This industry overview features several of these projects and offers a preview of 1993 activity. The only operating privately owned hydroelectric project in Texas. The largest hydro plant in the province of Manitoba. The world's largest submersible hydroturbine-generator. These projects and others-completed and placed in service in 1992-can claim a special place in the history books. For each of the 31 hydro projects in North America that began operating in 1992, there's a unique story to tell. Each called upon the time, talent, commitment, ingenuity, and perseverance of those involved in their development. In aggregate, these projects contribute nearly 3,800 MW of clean, renewable electrical capacity that can be used efficiently and cost-effectively to help meet the power demands of customers in the US and Canada. Utilities, state agencies, municipalities, and independent power developers played roles in developing new hydro in 1992. We offer a sampling of their work to illustrate progress made in the past year

  10. Ecosystem biophysical memory in the southwestern North America climate system

    International Nuclear Information System (INIS)

    To elucidate the potential role of vegetation to act as a memory source in the southwestern North America climate system, we explore correlation structures of remotely sensed vegetation dynamics with precipitation, temperature and teleconnection indices over 1982–2006 for six ecoregions. We found that lagged correlations between vegetation dynamics and climate variables are modulated by the dominance of monsoonal or Mediterranean regimes and ecosystem-specific physiological processes. Subtropical and tropical ecosystems exhibit a one month lag positive correlation with precipitation, a zero- to one-month lag negative correlation with temperature, and modest negative effects of sea surface temperature (SST). Mountain forests have a zero month lag negative correlation with precipitation, a zero–one month lag negative correlation with temperature, and no significant correlation with SSTs. Deserts show a strong one–four month lag positive correlation with precipitation, a low zero–two month lag negative correlation with temperature, and a high four–eight month lag positive correlation with SSTs. The ecoregion-specific biophysical memories identified offer an opportunity to improve the predictability of land–atmosphere interactions and vegetation feedbacks onto climate. (letter)

  11. Monarch butterfly migration and parasite transmission in eastern North America.

    Science.gov (United States)

    Bartel, Rebecca A; Oberhauser, Karen S; De Roode, Jacobus C; Altizer, Sonia M

    2011-02-01

    Seasonal migration occurs in many animal systems and is likely to influence interactions between animals and their parasites. Here, we focus on monarch butterflies (Danaus plexippus) and a protozoan parasite (Ophryocystis elektroscirrha) to investigate how host migration affects infectious disease processes. Previous work showed that parasite prevalence was lower among migratory than nonmigratory monarch populations; two explanations for this pattern are that (1) migration allows animals to periodically escape contaminated habitats (i.e., migratory escape), and (2) long-distance migration weeds out infected animals (i.e., migratory culling). We combined field-sampling and analysis of citizen science data to examine spatiotemporal trends of parasite prevalence and evaluate evidence for these two mechanisms. Analysis of within-breeding-season variation in eastern North America showed that parasite prevalence increased from early to late in the breeding season, consistent with the hypothesis of migratory escape. Prevalence was also positively related to monarch breeding activity, as indexed by larval density. Among adult monarchs captured at different points along the east coast fall migratory flyway, parasite prevalence declined as monarchs progressed southward, consistent with the hypothesis of migratory culling. Parasite prevalence was also lower among monarchs sampled at two overwintering sites in Mexico than among monarchs sampled during the summer breeding period. Collectively, these results indicate that seasonal migration can affect parasite transmission in wild animal populations, with implications for predicting disease risks for species with threatened migrations. PMID:21618914

  12. Energy balances for Europe and North America 1970-2000

    International Nuclear Information System (INIS)

    This publication is based on the ECE Energy Data Bank collected by the Senior Advisers to ECE Governments on Energy, supplemented by other official data available to the secretariat. The Energy Data Base contains energy balances from 1960 to 1985 for the market economy countries of western Europe and North America and from 1965 to 1985 for the centrally planned economy countries of eastern Europe. During the first session of the Senior Advisers to ECE Governments on Energy held in 1979, countries decided to circulate a questionnaire on Selected Energy Issues covering the years 1973, 1978, 1980, 1985, 1990 and 2000 (ECE/ENERGY/2, para. 29). While the methodology for establishing the balances has been mutually agreed, the assumptions underlying each country's forecast are not necessarily comparable. At their fifth session held from 23 to 27 September 1985, the Senior Advisers to ECE Governments on Energy agreed to issue a second questionnaire to collect revised projections for the years 1990 and 2000 (ECE/ENERGY/11, para. 50(b)). Information received served as benchmarks to construct a time series from 1970 to 1985. Commodities listed include solid fossil fuels, petroleum fuels, gaseous fuels both natural and derived, nuclear energy, hydro- and geothermal energy, electricity, steam and hot water, energy derived from non-conventional energy sources (solar, wind, wave, tidal, etc.)

  13. Sustainable energy developments in Europe and North America

    International Nuclear Information System (INIS)

    Europe and North America account for 70% of world energy consumption, 61% of which are fossil fuels. Energy trends and patterns in this region, if pursued, would heavily impact on region- and world-wide energy and ecosystems. Would projected trends and supply structures by ''sustainable'', i.e. ''meet the needs of the present without compromising the ability of future generations to meet their own needs'' (World Commission on Environment and Development)? What adaptations are warranted? What role could and should be played by regional energy and environmental co-operation, including through the United Nations Economic Commission for Europe? These are the issues dealt with by the present study mandated by the Senior Advisers to ECE Governments on Energy - a principal subsidiary body of the UN-ECE - in 1988 and reviewed in 1990. In line with a decision taken by the Senior Advisers to ECE Governments on Energy at their seventh session in October 1990, the study is released to the public domain, as customary under the responsibility of the secretariat. Refs, figs and tabs

  14. School and community relations in North America: Creative tensions

    Science.gov (United States)

    Loughran, E.; Reed, H. B.

    1980-09-01

    School and community relations in North America reflect creative tensions between the conserving forces of schooling and the changing forces of community. During crisis periods community development needs may modify the school's focus on individual learner growth, but generally schools use the community to extend and enrich the traditional modes. School and community interactions are chiefly characterized by such settings as community schools, community education, adult education, home and school (PTA) associations, work-study programs, curriculum-community resource programs. Recent social forces are creating heightened tensions: cultural pluralism, reduced resources, Third World influences, international conflicts, personal alienation, population concerns, energy problems, community power issues. These forces are gradually shifting school and community concepts towards ones of education and community. Education goes well beyond schooling, including all agencies having an organized influence on community development: libraries, voluntary groups, unions, business, human service agencies, government units, as well as schools. This shift requires research to develop nonformal concepts and practices, along with formal pedagogy, to increase the positive impacts of educational networks on community, as well as individual, development. These new directions have not yet significantly modified the traditional meaning of school and community relations.

  15. Boettger stoneware from North America and Europe; are they authentic

    International Nuclear Information System (INIS)

    In the early 18th century, Johann Friedrich Boettger, an alchemist recently arrived in Dresden, was assigned to ceramic experimentation under the orders of Augustus the Strong, Elector of Saxony and King of Poland. The Elector and his advisors hoped to discover the secret of making hard paste porcelain like the wares imported into Europe from China and Japan. In 1706-1707, Boettger produced his first ceramic body, a red stoneware similar to the wares produced in Yixing, China. The first objects were made following the forms of chinese prototypes or European metalwork of the period. Recently, the authenticity of a number of 'Boettger' objects in various museums and private collections in North America and Europe has been questioned. To aide in resolving these questions several non-destructive analytical techniques have been employed, the most important being PIXE. This report is on an initial study of 25 objects with 16 elements from Al to Zr and Pb being analysed. The results strongly suggest three different groupings, one of objects from the Meissen factory during the 20th century, one from the work of Boettger himself early in the 18th century and one from an as yet unknown time period and site. The first two groups were previously identified by one of the authors (C.N.)

  16. New and little known species of Lepechinella (Crustacea, Amphipoda, Lepechinellidae and an allied new genus Lepesubchela from the North Atlantic

    Directory of Open Access Journals (Sweden)

    Per-Otto Johansen

    2015-06-01

    Full Text Available New species of Lepechinella, L. norvegica sp. nov. and L. victoriae sp. nov., from the North East Atlantic are described together with the new, closely related genus and species Lepesubchela christinae gen. et sp. nov. Lepechinella arctica Schellenberg, 1926 from north of Spitsbergen and Lepechinella schellenbergi Stephensen, 1944 from Greenland are redescribed. A key to the species of Atlantic and Arctic Lepechinella is provided. Descriptions of taxonomic characters from related species in the Atlantic and Arctic are discussed.

  17. Chronological history of zebra and quagga mussels (Dreissenidae) in North America, 1988-2010

    Science.gov (United States)

    Benson, Amy J.

    2013-01-01

    An unprecedented invasion began in North America in the mid-/late-1980s when two Eurasian mussel species, Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel), became established in Laurentian Great Lakes. It is believed that Lake Erie was the initial location of establishment for both species, and within 3 years, zebra mussels had been found in all the Great Lakes. Since 1986, the combined distribution of two dreissenids has expanded throughout the Great Lakes region and the St. Lawrence River in Canada and also in the United States from the Great Lakes to the Mississippi Basin including Arkansas, Cumberland, Illinois, Missouri, Ohio, and Tennessee river basins. The distribution of dreissenid mussels in the Atlantic drainage has been limited to the Hudson and Susquehanna rivers. In the western United States, the quagga mussel established a large population in the lower Colorado River and spread to reservoirs in Arizona, California, Colorado, Nevada, and Utah. Overall, dreissenid species have been documented in 131 river systems and 772 inland lakes, reservoirs, and impoundments in the United States.

  18. Historical North Atlantic Tropical Cyclone Tracks 1851-2005, Geographic NAD83, NOAA (2006) [atlantic_hurricane_tracks_1851_2005_NOAA_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — This Historical North Atlantic Tropical Cyclone Tracks file contains the 6-hourly (0000, 0600, 1200, 1800 UTC) center locations and intensities for all subtropical...

  19. A synthesis of ENSO effects on drylands in Australia, North America and South America

    Science.gov (United States)

    Holmgren, M.; Stapp, P.; Dickman, C. R.; Gracia, C.; Graham, S.; Gutiérrez, J. R.; Hice, C.; Jaksic, F.; Kelt, D. A.; Letnic, M.; Lima, M.; López, B. C.; Meserve, P. L.; Milstead, W. B.; Polis, G. A.; Previtali, M. A.; Richter, M.; Sabaté, S.; Squeo, F. A.

    2006-01-01

    Fundamentally, El Niño Southern Oscillation (ENSO) is a climatic and oceanographic phenomenon, but it has profound effects on terrestrial ecosystems. Although the ecological effects of ENSO are becoming increasingly known from a wide range of terrestrial ecosystems (Holmgren et al., 2001), their impacts have been more intensively studied in arid and semiarid systems. In this brief communication, we summarize the main conclusions of a recent symposium on the effects of ENSO in these ecosystems, which was convened as part of the First Alexander von Humboldt International Conference on the El Niño Phenomenon and its Global Impact, in Guayaquil, Ecuador, from 16-20 May 2005. Participants in the symposium shared results and perspectives from research conducted in North and South America and Australia, regions where the ecological effects of ENSO have been studied in depth. Although the reports covered a wide array of organisms and ecological systems (Fig. 1), a recurring theme was the strong increase in rainfall associated with ENSO events in dry ecosystems (during the El Niño phase of the oscillation in the Americas and the La Niña phase in Australia). Because inter-annual variability in precipitation is such a strong determinant of productivity in arid and semiarid ecosystems, increased ENSO rainfall is crucial for plant recruitment, productivity and diversity in these ecosystems. Several long-term studies show that this pulse in primary productivity causes a subsequent increase in herbivores, followed by an increase in carnivores, with consequences for changes in ecosystem structure and functioning that can be quite complex.

  20. Managing weather and climate risks to agriculture in North America, Central America and the Caribbean

    Directory of Open Access Journals (Sweden)

    Harlan D. Shannon

    2015-12-01

    Full Text Available In recent decades, numerous weather- and climate-related natural disasters have impacted North America, Central America, and the Caribbean, repeatedly demonstrating how vulnerable local agriculture is to extreme episodic events. Given this recent history, and expectations that the frequency and intensity of some episodic events will increase with climate change, it is becoming increasingly important for farmers to proactively manage weather and climate risks to agriculture to protect their livelihoods. Some farmers in this region already apply various strategies to help reduce weather and climate risks and uncertainties, including farming in multiple locations, diversifying crops and varieties, seeking alternative sources of income, and purchasing crop insurance. Such efforts often help farmers maintain a more stable income while also protecting and preserving the productivity of the land. Other farmers, however, have failed to implement basic risk management strategies despite the clear benefits. Reasons for these failures can be attributed to inadequate farmer education and training, a lack of tools to help facilitate the practical application of risk management concepts, and poor communications between the agrometeorological and farming communities. The agrometeorological community can help overcome these obstacles by building upon existing efforts that have successfully educated farmers about weather and climate risks to agriculture and have equipped farmers with the data, tools, and applications necessary to manage these risks. Farmer input is critical to preparing effective educational and training materials and developing user-friendly risk management tools. The agrometeorological community should solicit input from farmers regularly to ensure that farmers are obtaining the information necessary to effectively manage weather and climate risks to agriculture.

  1. USGS Small-scale Dataset - Bathymetry of North America 200506 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Bathymetry of North America map layer shows depth ranges using colors. The image was derived from the National Geophysical Data Center's ETOPO2 elevation data,...

  2. USGS Small-scale Dataset - Bathymetric Shaded Relief of North America 200509 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Bathymetric Shaded Relief of North America map layer shows depth ranges using colors, with relief enhanced by shading. The image was derived from the National...

  3. Platycorypha nigrivirga Burckhardt (Hemiptera: Sternorrhyncha: Psylloidea), tipu psyllid, new to North America

    OpenAIRE

    Rung,Alessandra; Arakelian, Gevork; Gill, Ray; Nisson, Nick

    2009-01-01

    The tipu psyllid, Platycorypha nigrivirga Burckhardt (Hemiptera: Sternorrhyncha: Psylloidea), is reported for the first time in North America (USA: California). Diagnostic characters for identification of adults and nymphs, host and damage data, and known distribution are given.

  4. Notes on Clavarioid fungi—IX. Addendum to Clavulinopsis in North America

    NARCIS (Netherlands)

    Petersen, Ronald H.

    1971-01-01

    This paper constitutes an addendum to a previous paper by the author on the genus Clavulinopsis in North America. One new species is described, Clavulinopsis subaustralis Petersen, and one new combination made, Clavulinopsis laeticolor f. coccineo-basalis (Joss.) Petersen.

  5. STUDIES ON RARE AND POORLY KNOWN LEECHES (ANNELIDA: HIRUDINEA: GLOSSIPHONIIDAE) IN EASTERN NORTH AMERICA

    Science.gov (United States)

    Three taxa within the leech family Glossiphoniidae, Actinobdella inequiannulata, Placobdella hollensis, and Theromyzon spp., though widespread in eastern North America, remain poorly known with respect to their biology and systematics. All three taxa have been collected in New E...

  6. Color North America Shaded Relief – 1-Kilometer Resolution - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The North America Shaded Relief data were derived from the GTOPO30 elevation data. GTOPO30 is a global digital elevation model (DEM) with a horizontal grid spacing...

  7. Eelgrass (Zostera marina) Microsatellite DNA Data; Pacific Coast of North America, 2000-2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains genetic information collected from eelgrass (Zostera marina) populations along the Pacific coast of North America from Alaska to Baha...

  8. 78 FR 14778 - Application to Export Electric Energy; Shell Energy North America (US), L.P.

    Science.gov (United States)

    2013-03-07

    ...Shell Energy North America (US), L.P. (Shell Energy) has applied to renew its authority to transmit electric energy from the United States to Mexico pursuant to section 202(e) of the Federal Power...

  9. 78 FR 14779 - Application to Export Electric Energy; Shell Energy North America (US), L.P.

    Science.gov (United States)

    2013-03-07

    ...Shell Energy North America (US), L.P. (Shell Energy) has applied to renew its authority to transmit electric energy from the United States to Canada pursuant to section 202(e) of the Federal Power...

  10. Interdecadal North-Atlantic meridional overturning circulation variability in EC-EARTH

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, Bert; Drijfhout, Sybren; Hazeleger, Wilco

    2012-12-15

    The Atlantic meridional overturning circulation (AMOC) in a 600 years pre-industrial run of the newly developed EC-EARTH model features marked interdecadal variability with a dominant time-scale of 50-60 years. An oscillation of approximately 2 Sverdrup (1 Sv = 10{sup 6} m{sup 3} s{sup -1}) is identified, which manifests itself as a monopole causing the overturning to simultaneously strengthen (/weaken) and deepen (/shallow) as a whole. Eight years before the AMOC peaks, density in the Labrador-Irminger Sea region reaches a maximum, triggering deep water formation. This density change is caused by a counterclockwise advection of temperature and salinity anomalies at lower latitudes, which we relate to the north-south excursions of the subpolar-subtropical gyre boundary and variations in strength and position of the subpolar gyre and the North Atlantic Current. The AMOC fluctuations are not directly forced by the atmosphere, but occur in a delayed response of the ocean to forcing by the North Atlantic Oscillation, which initiates ''intergyre''-gyre fluctuations. Associated with the AMOC is a 60-year sea surface temperature variability in the Atlantic, with a pattern and timescale showing similarities with the real-world Atlantic Multidecadal Variability. This good agreement with observations lends a certain degree of credibility that the mechanism that is described in this article could be seen as representative of the real climate system. (orig.)

  11. Corporate responsibility reporting of the largest forest industry companies in North America

    OpenAIRE

    Li, Ning

    2009-01-01

    Forest products marketing This exploratory study aims to analyze the CR reporting by eleven largest forest products companies in North America. Both annual reports and sustainability reports produced in year 2006 by eleven largest forest products companies in North America were chosen for this very study. To ensure the comparability of the results, the study adopts the similar variables in operationalizations by Routto (2008), who studied the CR reporting of European forest products compan...

  12. Emerging Themes in Residential Child and Youth Care Practice in North America

    OpenAIRE

    Garfat, Thom

    2003-01-01

    Child and Youth Care practice in North America is, as it should be, in constant evolution. A review of the literature, conversations about practice and participation in the activities of the field reveal certain treads or themes which reft.ect the state of the field at this particular point in time. This paper identifies and reft.ects on some of those that seem most relevant to contemporary Child and Youth Care practice in North America.

  13. Necrotizing Fasciitis Caused by Hypermucoviscous Klebsiella pneumoniae in a Filipino Female in North America

    OpenAIRE

    Ng, Daniel; Frazee, Brad

    2014-01-01

    Necrotizing fasciitis caused by Klebsiella pneumoniae has been described in Southeast Asia, but has only recently begun to emerge in North America. The hypermucoviscous strain of K. pneumoniae is a particularly virulent strain known to cause devastatingly invasive infections, including necrotizing fasciitis. Here we present the first known case of necrotizing fasciitis caused by hypermucoviscous K. pneumoniae in North America. [West J Emerg Med. 2015;16(1):–0.

  14. Oral rabies vaccination in north america: opportunities, complexities, and challenges.

    Science.gov (United States)

    Slate, Dennis; Algeo, Timothy P; Nelson, Kathleen M; Chipman, Richard B; Donovan, Dennis; Blanton, Jesse D; Niezgoda, Michael; Rupprecht, Charles E

    2009-01-01

    Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV). Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, and research in border areas among Canada, Mexico, and the US. Advances in enhanced surveillance have facilitated sampling of greater scope and intensity near ORV zones for improved rabies management decision-making in real time. The value of enhanced surveillance as a complement to public health surveillance was best illustrated in Ohio during 2007, where 19 rabies cases were detected that were critical for the formulation of focused contingency actions for controlling rabies in this strategically key area. Diverse complexities and challenges are commonplace when applying ORV to control rabies in wild meso-carnivores. Nevertheless, intervention has resulted in notable successes, including the elimination of an arctic fox (Vulpes lagopus) rabies virus variant in most of southern Ontario, Canada, with ancillary benefits of elimination extending into Quebec and the northeastern US. Progress continues with ORV toward preventing the spread and working toward elimination of a unique variant of gray fox (Urocyon cinereoargenteus) rabies in west central Texas. Elimination of rabies in coyotes (Canis latrans) through ORV contributed to the US being declared free of canine rabies in 2007. Raccoon (Procyon lotor) rabies control continues to present the greatest challenges among meso-carnivore rabies reservoirs, yet to date intervention has prevented this variant from gaining a broad geographic foothold beyond ORV zones designed to prevent its spread from the eastern US. Progress continues

  15. Knowledge exchange for climate adaptation planning in western North America

    Science.gov (United States)

    Garfin, Gregg; Orr, Barron

    2015-04-01

    In western North America, the combination of sustained drought, rapid ecosystem changes, and land use changes associated with urban population growth has motivated concern among ecosystem managers about the implications of future climate changes for the landscapes which they manage. Through literature review, surveys, and workshop discussions, we assess the process of moving from concern, to planning, to action, with an emphasis on questions, such as: What are the roles of boundary organizations in facilitating knowledge exchange? Which practices lead to effective interactions between scientists, decision-makers, and knowledge brokers? While there is no "one size fits all" science communication method, the co-production of science and policy by research scientists, science translators, and decision-makers, as co-equals, is a resource intensive, but effective practice for moving adaptation planning forward. Constructive approaches make use of alliances with early adopters and opinion leaders, and make strong communication links between predictions, impacts and solutions. Resource managers need information on the basics of regional climate variability and global climate change, region-specific projections of climate changes and impacts, frank discussion of uncertainties, and opportunities for candid exploration of these topics with peers and subject experts. Research scientists play critical roles in adaptation planning discussions, because they assist resource managers in clarifying the cascade of interactions leading to potential impacts and, importantly, because decision-makers want to hear the information straight from the scientists conducting the research, which bolsters credibility. We find that uncertainty, formerly a topic to avoided, forms the foundation for constructive progress in adaptation planning. Candid exploration of the array of uncertainties, including those due to modeling, institutional, policy and economic factors, with practitioners, science

  16. Economics issues - nuclear power generation in North America

    International Nuclear Information System (INIS)

    The structure of the US utility industry is in transition. Political, social, and economic factors are contributing to a rapid shift from a monopoly structure (captive markets, cost-plus prices, negotiated rate of return on capital) to a highly competitive one (choices for customers, prices determined by the market place, earnings based on market price less cost). The rate of change has been accelerating. For example, what just two years ago would have been thought of as highly unlikely -- competition for the individual electric customer -- is now part of the plan in California and other states. In our view, technology is at the root of many of these structural changes with more to come. Yet another round of technological change is afoot, involving even more efficient gas turbines, new methods of utilizing transmission lines, distributed generation, and new opportunities for electricity use and service. It can be argued that the restructuring of the marketplace reflects, in some measure, anticipation for these advances. For the foreseeable future, nuclear energy will continue to play a significant role in the generating grid of North America. However, new nuclear generation will be held to standards of competition that are dictated by market forces, and by advances in competing technologies for base load generation. It is important to understand these forces, and devise a response which ensures that nuclear energy will continue to provide a viable, competitive, and environmentally superior option for generating electricity in the 21st century. The EPRI Nuclear Power program is focused on achieving these goals. (author)

  17. Oral rabies vaccination in north america: opportunities, complexities, and challenges.

    Directory of Open Access Journals (Sweden)

    Dennis Slate

    Full Text Available Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV. Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, and research in border areas among Canada, Mexico, and the US. Advances in enhanced surveillance have facilitated sampling of greater scope and intensity near ORV zones for improved rabies management decision-making in real time. The value of enhanced surveillance as a complement to public health surveillance was best illustrated in Ohio during 2007, where 19 rabies cases were detected that were critical for the formulation of focused contingency actions for controlling rabies in this strategically key area. Diverse complexities and challenges are commonplace when applying ORV to control rabies in wild meso-carnivores. Nevertheless, intervention has resulted in notable successes, including the elimination of an arctic fox (Vulpes lagopus rabies virus variant in most of southern Ontario, Canada, with ancillary benefits of elimination extending into Quebec and the northeastern US. Progress continues with ORV toward preventing the spread and working toward elimination of a unique variant of gray fox (Urocyon cinereoargenteus rabies in west central Texas. Elimination of rabies in coyotes (Canis latrans through ORV contributed to the US being declared free of canine rabies in 2007. Raccoon (Procyon lotor rabies control continues to present the greatest challenges among meso-carnivore rabies reservoirs, yet to date intervention has prevented this variant from gaining a broad geographic foothold beyond ORV zones designed to prevent its spread from the eastern US

  18. Arctic sea ice bordering on the North Atlantic and intera- nnual climate variations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Variations of winter Arctic sea ice bordering on the North Atlantic are closely related to climate variations in the same region. When winter North Atlantic Oscillation (NAO) index is positive (negative) anomaly phase, Icelandic Low is obviously deepened and shifts northwards (southwards). Simultaneously, the Subtropical High over the North Atlantic is also intensified, and moves northwards (south-wards). Those anomalies strengthen (weaken) westerly be-tween Icelandic Low and the Subtropical High, and further result in positive (negative) sea surface temperature (SST) anomalies in the mid-latitude of the North Atlantic, and increase (decrease) the warm water transportation from the mid-latitude to the Barents Sea, which causes positive (nega-tive) mixed-layer water temperature anomalies in the south part of the Barents Sea. Moreover, the distribution of anom-aly air temperature clearly demonstrates warming (cooling) in northern Europe and the subarctic regions (including the Barents Sea) and cooling (warming) in Baffin Bay/ Davis Strait. Both of distributions of SST and air temperature anomalies directly result in sea ice decrease (increase) in the Barents/Kara Seas, and sea ice increase (decrease) in Baffin Bay/Davis Strait.

  19. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Visser, Andre; Richardson, Katherine;

    2015-01-01

    Significance Every autumn across the North Atlantic, large numbers of zooplankton copepods migrate from the surface waters into the ocean's interior to hibernate at depths of 600–1,400 m. Through this migration, they actively transport lipid carbon to below the permanent thermocline, where it is...

  20. Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    T. Morato

    2013-05-01

    Full Text Available This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic and in the Mediterranean Sea is large with around 557 and 101 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 616 000 km2 in the OSPAR region and of about 89 500 km2 in the Mediterranean Sea. The presence of seamounts in the north-east Atlantic has been known since the late 19th century, but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region, 22 in the Mediterranean Sea (9.2% of all seamounts in the region and 25 in the north-east Atlantic south of the OSPAR area have in situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms.

  1. Synoptic scale analysis of mechanisms driving surface chlorophyll dynamics in the North Atlantic

    Directory of Open Access Journals (Sweden)

    A. S. A. Ferreira

    2015-01-01

    Full Text Available Several hypotheses have been proposed for phytoplankton bloom onset in the North Atlantic. The physical properties driving phytoplankton seasonality can also be used as indicators of the greening of the oceans. Our main objective is to examine which bottom-up processes can best predict changes in the growing phase of phytoplankton surface blooms in the North Atlantic, by applying novel phenology algorithms to ocean colour data. We construct indicator fields and time series which, in various combinations, provide models consistent with the principle dynamics previously proposed. Using a multi-model inference approach, we investigate the evidence supporting these models, and how it varies in space. We show that, in terms of bottom-up processes alone, there is a dominant physical mechanism (mixed layer shoaling best predicting the North Atlantic phytoplankton surface chlorophyll. We further show that different regions are governed by different physical phenomena, and that wind-driven mixing is a common component with either heat flux or light as triggers. We believe these findings to be relevant for the ongoing discussion on North Atlantic bloom onset.

  2. Restoration and enhancement of Atlantic salmon populations: what we have learned from North Iberian rivers

    OpenAIRE

    Horreo J.L.; De La Hoz J.; Machado-Schiaffino G.; Pola I.G.; Garcia-Vazquez E.

    2012-01-01

    Found on the southernmost edge of the species’ natural distribution, North Iberian Atlantic salmon populations are extremely vulnerable to environmental change. In the last few decades, associated with global indicators of climate change, these populations have been experiencing a sharp decline. Efforts have been made to address their decline, principally through stocking, supportive breeding and habitat restoration...

  3. WATERFOWL-HABITAT ASSOCIATIONS DURING WINTER IN A URBAN NORTH ATLANTIC ESTUARY

    Science.gov (United States)

    Coastal habitats near urban centres in North Atlantic estuaries often support substantial numbers of wintering waterfowl, but little is known of the effects of landscape setting and urbanisation on habitat use. We conducted surveys of waterfowl at 32 wintering sites in Narraganse...

  4. RIVALITAS PERANCIS-AMERIKA SERIKAT DI NORTH ATLANTIC TREATY ORGANIZATION PASCA PERANG DINGIN

    OpenAIRE

    RIO ARIANTO, ADI

    2012-01-01

    Penelitian ini menggambarkan tentang rivalitas antara Perancis dan Amerika Serikat di North Atlantic Treaty Organization (NATO) pasca Perang Dingin. Pembahasan ini difokuskan pada konflik kepentingan antara Perancis dan Amerika Serikat di NATO. Penelitian ini mencoba memahami perilaku kedua negara ??????Perancis dan Amerika Serikat di NATO, kemudian menelaah pengaruhnya terhadap bentuk kebijakan dan kinerja NATO dalam melihat postur keamanan internasional di masa kekinian. Metode Penelitia...

  5. 77 FR 22221 - Security Zones; North Atlantic Treaty Organization (NATO) Summit, Chicago, IL

    Science.gov (United States)

    2012-04-13

    ...) Summit, Chicago, Illinois in the Federal Register (77 FR 13232). Although the G8 Summit is now planned to... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; North Atlantic Treaty Organization (NATO... NATO Summit and associated events, which will be held in Chicago from May 16, 2012, through May...

  6. 77 FR 25892 - Security Zones; North Atlantic Treaty Organization (NATO) Summit, Chicago, IL

    Science.gov (United States)

    2012-05-02

    ... proposed rule (77 FR 13232) that would establish four separate security zones in the Chicago Harbor and Chicago River during the NATO Summit. This statement is incorrect. The Coast Guard received one comment... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA87 Security Zones; North Atlantic Treaty Organization...

  7. Nearshore marine benthic invertebrates moving north along the U.S. Atlantic coast

    Science.gov (United States)

    Numerous species have shifted their ranges north in response to global warming. We examined 21 years (1990-2010) of marine benthic invertebrate data from the National Coastal Assessment’s monitoring of nearshore waters along the US Atlantic coast. Data came from three bioge...

  8. Rosacea flaccida n. sp., a new species of siphonophore (Calycophorae Prayinae) from the North Atlantic Ocean

    NARCIS (Netherlands)

    Biggs, D.C.; Pugh, P.R.; Carré, C.

    1978-01-01

    Rosacea flaccida, a new prayine siphonophore, is described from specimens collected by SCUBA divers in the upper 30m of the subtropical and temperate North Atlantic Ocean. The new species has stoutly cylindrical, flaccid nectophores and delicate flattened bracts. The nectophores are morphologically

  9. Using species-area relationships to inform baseline conservation targets for the deep North East Atlantic.

    Science.gov (United States)

    Foster, Nicola L; Foggo, Andrew; Howell, Kerry L

    2013-01-01

    Demands on the resources of the deep-sea have increased in recent years. Consequently, the need to create and implement a comprehensive network of Marine Protected Areas (MPAs) to help manage and protect these resources has become a global political priority. Efforts are currently underway to implement MPA networks in the deep North East Atlantic. To ensure these networks are effective, it is essential that baseline information be available to inform the conservation planning process. Using empirical data, we calculated conservation targets for sessile benthic invertebrates in the deep North East Atlantic for consideration during the planning process. We assessed Species-Area Relationships across two depth bands (200-1100 m and 1100-1800 m) and nine substrata. Conservation targets were predicted for each substratum within each depth band using z-values obtained from fitting a power model to the Species-Area Relationships of observed and estimated species richness (Chao1). Results suggest an MPA network incorporating 10% of the North East Atlantic's deep-sea area would protect approximately 58% and 49% of sessile benthic species for the depth bands 200-1100 m and 1100-1800 m, respectively. Species richness was shown to vary with substratum type indicating that, along with depth, substratum information needs to be incorporated into the conservation planning process to ensure the most effective MPA network is implemented in the deep North East Atlantic. PMID:23527053

  10. Parasitic anemone infects the invasive ctenophore Mnemiopsis leidyi in the North East Atlantic

    DEFF Research Database (Denmark)

    Selander, Erik; Møller, Lene Friis; Sundberg, Per;

    2010-01-01

    We report of the first finding of parasitic sea anemone larvae infecting the invasive ctenophore Mnemiopsis leidyi in the North East Atlantic. Parasitic anemone larvae are common in the native habitat of Mnemiopsis, but have not previously been reported from any of the locations where Mnemiopsis...

  11. Estimating the North Atlantic mean dynamic topography and geostrophic currents with GOCE

    DEFF Research Database (Denmark)

    Bingham, Rory J.; Knudsen, Per; Andersen, Ole Baltazar

    2011-01-01

    Three GOCE gravity models were released in July 2010 based on two months of observations. Subsequently, two second generation models, based on 8 months of observations, were released in March 2011. This paper compares these five models in terms of the mean North Atlantic circulation that can be d...

  12. Whales, Dolphins, and Porpoises of the Western North Atlantic: A Guide to Their Identification.

    Science.gov (United States)

    Leatherwood, Stephen; And Others

    This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in western North Atlantic, including the Caribbean Sea, the Gulf of Mexico, and the coastal waters of the United States and Canada. The animals described are not grouped by scientific relationships but by similarities in appearance…

  13. A new Benthopelagic species of Heterokrohnia (Chaetognatha) from the North Atlantic Ocean

    NARCIS (Netherlands)

    Casanova, Jean-Paul; Chidgey, Kathleen

    1990-01-01

    A new species of Heterokrohnia, H. mirabiloides, is described from the “Discovery” collections made in the North-East Atlantic. It differs from the two other species of the “mirabilis” group mainly in the cephalic armature, particularly the posterior teeth which are much less numerous and bent at ri

  14. A short note on the biogeographic patterns of the Chaetognatha fauna in the North Atlantic

    NARCIS (Netherlands)

    A.C. Pierrot-Bults

    2008-01-01

    Three different hydrographic regimes were identified during the MAR-ECO cruise in the North Atlantic in June 2004 between 59°N and 42°N. Chaetognaths were sampled with a non-quantitative open plankton net through the entire water column. The species composition of the chaetognaths differed between t

  15. Surface temperatures of the Mid-Pliocene North Atlantic Ocean: Implications for future climate

    Science.gov (United States)

    Dowsett, H.J.; Chandler, M.A.; Robinson, M.M.

    2009-01-01

    The Mid-Pliocene is the most recent interval in the Earth's history to have experienced warming of the magnitude predicted for the second half of the twenty-first century and is, therefore, a possible analogue for future climate conditions. With continents basically in their current positions and atmospheric CO2 similar to early twenty-first century values, the cause of Mid-Pliocene warmth remains elusive. Understanding the behaviour of the North Atlantic Ocean during the Mid-Pliocene is integral to evaluating future climate scenarios owing to its role in deep water formation and its sensitivity to climate change. Under the framework of the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) sea surface reconstruction, we synthesize Mid-Pliocene North Atlantic studies by PRISM members and others, describing each region of the North Atlantic in terms of palaeoceanography. We then relate Mid-Pliocene sea surface conditions to expectations of future warming. The results of the data and climate model comparisons suggest that the North Atlantic is more sensitive to climate change than is suggested by climate model simulations, raising the concern that estimates of future climate change are conservative. ?? 2008 The Royal Society.

  16. High frequency variability in recent climate and the North Atlantic Oscillation

    Czech Academy of Sciences Publication Activity Database

    Bodri, L.; Čermák, Vladimír

    2003-01-01

    Roč. 74, 1/2 (2003), s. 33-40. ISSN 0177-798X R&D Projects: GA AV ČR IAA3012005 Institutional research plan: CEZ:AV0Z3012916 Keywords : North Atlantic Oscillation * recent climate * temperature variability Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.147, year: 2003

  17. On the ocurrence of Groszwetterlagen in winter related to anomalies in North Atlantic sea temperature

    NARCIS (Netherlands)

    Oerlemans, J.

    1975-01-01

    In this article, the main results of an investigation concerning the relation between deviating Atlantic sea temperatures and the frequency of occurrence of "Grof wetterlagen" in winter are presented. It appeared that blocking systems over North-west Europe more frequently occur if in the northern p

  18. Continental outflow from the US to the upper troposphere over the North Atlantic during the NASA INTEX-NA Airborne Campaign

    Directory of Open Access Journals (Sweden)

    S. Y. Kim

    2008-04-01

    Full Text Available A case of continental outflow from the United States (US was examined using airborne measurements from NASA DC-8 flight 13 during the Intercontinental Chemical Transport Experiment – North America (INTEX-NA. Mixing ratios of methane (CH4 and carbon monoxide (CO at 8–11 km altitude over the North Atlantic were elevated to 1843 ppbv and 134 ppbv respectively, while those of carbon dioxide (CO2 and carbonyl sulfide (COS were reduced to 372.4 ppmv and 411 pptv respectively. In this region, urban and industrial influences were evidenced by elevated mixing ratios and good linear relationships between urban and industrial tracers compared to North Atlantic background air. Moreover, low mixing ratios and a good correlation between COS and CO2 showed a fingerprint of terrestrial uptake and minimal dilution during rapid transport over a 1–2 day time period. Analysis of synoptic conditions, backward trajectories, and photochemical aging estimates based on C3H8/C2H6 strongly suggested that elevated anthropogenic tracers in the upper troposphere of the flight region were the result of transport via convection and warm conveyor belt (WCB uplifting of boundary layer air over the southeastern US. This mechanism is supported by the similar slope values of linear correlations between long-lived (months anthropogenic tracers (e.g., C2Cl4 and CHCl3 from the flight region and the planetary boundary layer in the southeastern US. In addition, the aircraft measurements suggest that outflow from the US augmented the entire tropospheric column at mid-latitudes over the North Atlantic. Overall, the flight 13 data demonstrate a pervasive impact of US anthropogenic emissions on the troposphere over the North Atlantic.

  19. Rapid convective outflow from the U.S. to the upper troposphere over the North Atlantic during the NASA INTEX-NA airborne campaign: flight 13 case study

    Directory of Open Access Journals (Sweden)

    S. Y. Kim

    2007-11-01

    Full Text Available A case study of convective outflow from the United States (U.S. was examined using airborne measurements from NASA DC-8 flight 13 during the Intercontinental Chemical Transport Experiment – North America (INTEX-NA. Mixing ratios of methane (CH4 and carbon monoxide (CO at 8–11 km altitude over the North Atlantic were elevated to 1843 ppbv and 134 ppbv respectively, while those of carbon dioxide (CO2 and carbonyl sulfide (COS were reduced to 372.4 ppmv and 411 pptv respectively. In this region, urban and industrial influence was evidenced by elevated mixing ratios and good linear relationships between urban and industrial tracers compared to North Atlantic background air. Moreover, low mixing ratios and a good correlation between COS and CO2 showed a fingerprint of terrestrial uptake and minimal dilution during rapid transport over a 1–2 day time period. Analysis of synoptic conditions, backward trajectories, and photochemical aging estimates based on C3H8/C2H6 strongly suggested that elevated anthropogenic tracers in the upper troposphere of the flight region were the result of fast transport via convective uplifting of boundary layer air over the southeastern U.S. This mechanism is supported by the similar slopes values of linear correlations between long-lived (months anthropogenic tracers (e.g., C2Cl4 and CHCl3 from the flight region and the planetary boundary layer in the southeastern U.S. In addition, the aircraft measurements suggest that outflow from the U.S. augmented the entire tropospheric column at mid-latitudes over the North Atlantic. Overall, the flight 13 data demonstrate a pervasive impact of U.S. anthropogenic emissions on the troposphere over the North Atlantic.

  20. Influence of small-scale North Atlantic sea surface temperature patterns on the marine boundary layer and free troposphere: a study using the atmospheric ARPEGE model

    Science.gov (United States)

    Piazza, Marie; Terray, Laurent; Boé, Julien; Maisonnave, Eric; Sanchez-Gomez, Emilia

    2016-03-01

    A high-resolution global atmospheric model is used to investigate the influence of the representation of small-scale North Atlantic sea surface temperature (SST) patterns on the atmosphere during boreal winter. Two ensembles of forced simulations are performed and compared. In the first ensemble (HRES), the full spatial resolution of the SST is maintained while small-scale features are smoothed out in the Gulf Stream region for the second ensemble (SMTH). The model shows a reasonable climatology in term of large-scale circulation and air-sea interaction coefficient when compared to reanalyses and satellite observations, respectively. The impact of small-scale SST patterns as depicted by differences between HRES and SMTH shows a strong meso-scale local mean response in terms of surface heat fluxes, convective precipitation, and to a lesser extent cloudiness. The main mechanism behind these statistical differences is that of a simple hydrostatic pressure adjustment related to increased SST and marine atmospheric boundary layer temperature gradient along the North Atlantic SST front. The model response to small-scale SST patterns also includes remote large-scale effects: upper tropospheric winds show a decrease downstream of the eddy-driven jet maxima over the central North Atlantic, while the subtropical jet exhibits a significant northward shift in particular over the eastern Mediterranean region. Significant changes are simulated in regard to the North Atlantic storm track, such as a southward shift of the storm density off the coast of North America towards the maximum SST gradient. A storm density decrease is also depicted over Greenland and the Nordic seas while a significant increase is seen over the northern part of the Mediterranean basin. Changes in Rossby wave breaking frequencies and weather regimes spatial patterns are shown to be associated to the jets and storm track changes.

  1. An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    S. Duperron

    2013-05-01

    Full Text Available Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae. Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

  2. The later evolution of modern sport in Latin America: the North American influence.

    Science.gov (United States)

    Arbena, J L

    2001-01-01

    American impact on modern sports in Latin America overlaps geographically and chronologically with the European, especially British, impact. Principally baseball in the Caribbean basin, more recently basketball and volleyball across the hemisphere and occasionally American football in more limited areas illustrate a north-to-south movement executed by businessmen, educators, missionaries, military personnel, returning travelers (often students), sports entrepreneurs and television. Often initially supported by promoters of development within Latin America, this transfer has altered local recreational patterns and attracted Latin athletes to pursue careers in North America, provoking accusations of cultural imperialism and exploitation. PMID:18592684

  3. The 2007 North Atlantic spring bloom in operational analysis from the TOPAZ system

    Directory of Open Access Journals (Sweden)

    A. Samuelsen

    2009-02-01

    Full Text Available A reanalysis of the North Atlantic spring bloom in 2007 was produced using the real-time analyses from the TOPAZ (Towards an Operational Prediction system for the North Atlantic European coastal Zones North Atlantic and Arctic forecasting system. The TOPAZ system uses a hybrid coordinate general circulation ocean model and assimilates physical observations: sea surface anomalies, sea surface temperatures, and sea-ice concentrations using the Ensemble Kalman Filter. This ocean model was coupled to an ecosystem model, NORWECOM (Norwegian Ecological Model System, and the TOPAZ-NORWECOM coupled model was run throughout the spring and summer of 2007. The ecosystem model was run online, restarting from analyzed physical fields (result after data assimilation every 7 days. Biological variables were not assimilated in the model. The forecast was compared to remotely sensed chlorophyll and in-situ data. The impact of physical data assimilation on the ecosystem model was determined by comparing the results to those from a model without assimilation of physical data. The regions of focus are the North Atlantic and the Arctic Ocean. The results show that the model reproduces a realistic annual cycle, but the chlorophyll concentrations tend to be too low during winter and spring and too high during summer. Surface nutrients on the other hand are generally too low throughout the year. Assimilation of physical variables does not affect the results from the ecosystem model significantly. The differences between the weekly mean values of chlorophyll are normally within 5–10% during the summer months, and the maximum difference of ~20% occurs in the Arctic, also during summer. Special attention was paid to the nutrient input from the North Atlantic to the Nordic Seas and the impact of ice-assimilation on the ecosystem. The ice-assimilation increased the phytoplankton concentration: because there was less ice in the assimilation run, this increased both the

  4. Synoptic eddy feedback and air-sea interaction in the North Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Lin-Lin [University of Hawaii at Manoa, International Pacific Research Center, Honolulu, HI (United States); University of California, Department of Land, Air and Water Resources, Davis, CA (United States)

    2007-11-15

    This paper explores the role of synoptic eddy feedback in the air-sea interaction in the North Atlantic region, particularly the interaction between the North Atlantic Oscillation (NAO) and the North Atlantic sea surface temperature anomalies (SSTA) tripole. A linearized five-layer primitive equation atmospheric model with synoptic eddy and low-frequency flow (SELF) interaction is coupled with a linearized oceanic mixed-layer model to investigate this issue. In this model, the ''climatological'' storm track/activity (or synoptic eddy activity) is characterized in terms of spatial structures, variances, decay time scales and propagation speeds through the complex empirical orthogonal function (CEOF) analysis on the observed data, which provides a unique tool to investigate the role of synoptic eddy feedback in the North Atlantic air-sea coupling. Model experiments show that the NAO-like atmospheric circulation anomalies can produce tripole-like SSTA in the North Atlantic Ocean, and the tripole-like SSTA can excite a NAO-like dipole with an equivalent barotropic structure in the atmospheric circulation, which suggests a positive feedback between the NAO and the SSTA tripole. This positive feedback makes the NAO/SSTA tripole-like mode be the leading mode of the coupled dynamical system. The synoptic eddy feedback plays an essential role in the origin of the NAO/SSTA tripole-like leading mode and the equivalent barotropic structure in the atmosphere. Without synoptic eddy feedback, the atmosphere has a baroclinic structure in the response field to the tripole-like SSTA forcing, and the leading mode of the dynamic system does not resemble NAO/SSTA tripole pattern. (orig.)

  5. On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?

    Science.gov (United States)

    Couldrey, Matthew P.; Oliver, Kevin I. C.; Yool, Andrew; Halloran, Paul R.; Achterberg, Eric P.

    2016-05-01

    The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2 concentration gradient, ΔpCO2, and the temperature- and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2 and k both contribute significantly to interannual F variability but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2, and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2 and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of nonseasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer-term flux variability.

  6. Impact of the North Atlantic Sea Surface Temperature Tripole on the East Asian Summer Monsoon

    Institute of Scientific and Technical Information of China (English)

    ZUO Jinqing; LI Weijing; SUN Chenghu; XU Li; REN Hong-Li

    2013-01-01

    A strong (weak) East Asian summer monsoon (EASM) is usually concurrent with the tripole pattern of North Atlantic SST anomalies on the interannual timescale during summer,which has positive (negative)SST anomalies in the northwestern North Atlantic and negative (positive) SST anomalies in the subpolar and tropical ocean.The mechanisms responsible for this linkage are diagnosed in the present study.It is shown that a barotropic wave-train pattern occurring over the Atlantic-Eurasia region likely acts as a link between the EASM and the SST tripole during summer.This wave-train pattern is concurrent with geopotential height anomalies over the Ural Mountains,which has a substantial effect on the EASM.Diagnosis based on observations and linear dynamical model results reveals that the mechanism for maintaining the wave-train pattern involves both the anomalous diabatic heating and synoptic eddy-vorticity forcing.Since the North Atlantic SST tripole is closely coupled with the North Atlantic Oscillation (NAO),the relationships between these two factors and the EASM are also examined.It is found that the connection of the EASM with the summer SST tripole is sensitive to the meridional location of the tripole,which is characterized by large seasonal variations due to the north-south movement of the activity centers of the NAO.The SST tripole that has a strong relationship with the EASM appears to be closely coupled with the NAO in the previous spring rather than in the simultaneous summer.

  7. Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America

    Science.gov (United States)

    The book “Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America” summarizes published research in soil science and agronomy from various field experiments conducted in the soil-climatic/agro-ecological regions of the Northern Great Plains of North America....

  8. Multi-decadal uptake of carbon dioxide into subtropical mode water of the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    N. R. Bates

    2012-07-01

    Full Text Available Natural climate variability impacts the multi-decadal uptake of anthropogenic carbon dioxide (Cant into the North Atlantic Ocean subpolar and subtropical gyres. Previous studies have shown that there is significant uptake of CO2 into subtropical mode water (STMW of the North Atlantic. STMW forms south of the Gulf Stream in winter and constitutes the dominant upper-ocean water mass in the subtropical gyre of the North Atlantic Ocean. Observations at the Bermuda Atlantic Time-series Study (BATS site near Bermuda show an increase in dissolved inorganic carbon (DIC of +1.51 ± 0.08 μmol kg−1 yr−1 between 1988 and 2011, but also an increase in ocean acidification indicators such as pH at rates (−0.0022 ± 0.0002 yr−1 higher than the surface ocean (Bates et al., 2012. It is estimated that the sink of CO2 into STMW was 0.985 ± 0.018 Pg C (Pg = 1015 g C between 1988 and 2011 (70 ± 1.8% of which is due to uptake of Cant. The sink of CO2 into the STMW is 20% of the CO2 uptake in the North Atlantic Ocean between 14°–50° N (Takahashi et al., 2009. However, the STMW sink of CO2 was strongly coupled to the North Atlantic Oscillation (NAO, with large uptake of CO2 into STMW during the 1990s during a predominantly NAO positive phase. In contrast, uptake of CO2 into STMW was much reduced in the 2000s during the NAO neutral/negative phase. Thus, NAO induced variability of the STMW CO2 sink is important when evaluating multi-decadal changes in North Atlantic Ocean CO2 sinks.

  9. Invasion of the red seaweed Heterosiphonia japonica spans biogeographic provinces in the Western North Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Christine Newton

    Full Text Available The recent invasion of the red alga Heterosiphonia japonica in the western North Atlantic Ocean has provided a unique opportunity to study invasion dynamics across a biogeographical barrier. Native to the western North Pacific Ocean, initial collections in 2007 and 2009 restricted the western North Atlantic range of this invader to Rhode Island, USA. However, through subtidal community surveys, we document the presence of Heterosiphonia in coastal waters from Maine to New York, USA, a distance of more than 700 km. This geographical distribution spans a well-known biogeographical barrier at Cape Cod, Massachusetts. Despite significant differences in subtidal community structure north and south of Cape Cod, Heterosiphonia was found at all but two sites surveyed in both biogeographic provinces, suggesting that this invader is capable of rapid expansion over broad geographic ranges. Across all sites surveyed, Heterosiphonia comprised 14% of the subtidal benthic community. However, average abundances of nearly 80% were found at some locations. As a drifting macrophyte, Heterosiphonia was found as intertidal wrack in abundances of up to 65% of the biomass washed up along beaches surveyed. Our surveys suggest that the high abundance of Heterosiphonia has already led to marked changes in subtidal community structure; we found significantly lower species richness in recipient communities with higher Heterosiphona abundances. Based on temperature and salinity tolerances of the European populations, we believe Heterosiphonia has the potential to invade and alter subtidal communities from Florida to Newfoundland in the western North Atlantic.

  10. Trophic ecology and bioindicator potential of the North Atlantic tope shark.

    Science.gov (United States)

    Torres, Paulo; da Cunha, Regina Tristão; Maia, Rodrigo; Dos Santos Rodrigues, Armindo

    2014-05-15

    Sharks are top marine predators vital in maintaining ecosystem health and food web structure. In order to assess tope shark (Galeorhinus galeus) trophic ecology, stable isotope ratios and trace metal concentrations in muscle tissue were determined, according to size and gender, for 124 individuals caught within the Mid-Atlantic region. Data was complemented and analysed according to previous stomach content information and compared with studies performed in the North East Atlantic. Our results revealed that tope sharks fed at a low trophic level and within a more pelagic-based food web when compared with other North Atlantic regions. MixSIR application reflected its piscivorous diet and study area topography, oligotrophic waters and volcanic nature, suggesting the occurrence of a Mid-Atlantic tope shark population. Considering a non-anthropogenic volcanic source for observed metal contents, the results reflect bioaccumulation and suggest biomagnification processes for As and Hg. These metals exceeded legislated maximum limits for some countries with a maximum of 28.98 ± 1.26 and 0.57 ± 0.01 mg kg(-1) wet weight, respectively, increasing significantly with size for both males and females. Conversely, Cr, Rb and Zn were relatively stable while Cd and Pb were not detected. Hg and Se were strongly correlated, suggesting a Se toxicity mitigation role. Given the tope shark travel capacity and the results obtained, the species may be used as a Mid-Atlantic bioindicator of environmental quality. PMID:24631620

  11. Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic

    Directory of Open Access Journals (Sweden)

    Detlev Helmig

    2015-08-01

    Full Text Available Abstract A record spanning ten years of non-methane hydrocarbon (NMHC data from the Pico Mountain Observatory (PMO, Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposphere. The quantity ln([propane]/[ethane] was used as an indicator of both photochemical processing and a marker for the occurrence of pollution transport events detected at the station. The Pico data were compared with three other continuous NMHC data sets from sites bordering the North Atlantic, i.e. the Global Atmospheric Watch (GAW stations at Summit, Greenland, Hohenpeisssenberg, Germany, and Cape Verde, using ln([propane]/[ethane] results as an indicator for the degree of photochemical processing (aging seen in the data. Comparisons of these three data sets showed some significant differences in the seasonal background and range of observed values. The statistical distribution of binned monthly data was determined, and individual sample events were then scaled to the monthly median observed value. Back trajectories, determined by the HYSPLIT model were used to investigate the geographic origin of the observed trace gases as a function of the degree of photochemical processing. Results show that PMO samples have been subjected to a diversity of air transport and aging, from highly processed air to freshly emitted air throughout the year, and in particular during summer months. The predominant air transport is from North America, with only occasional influence from continental areas located east and southeast (Europe and Africa. The available record was found to be too variable and still too short to allow deciphering NMHC trends from the data. Ethane and

  12. The Radiative Role of Free Tropospheric Aerosols and Marine Clouds over the Central North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Mazzoleni, Claudio [Michigan Technological University; Kumar, Sumit [Michigan Technological University; Wright, Kendra [Michigan Technological University; Kramer, Louisa [Michigan Technological University; Mazzoleni, Lynn [Michigan Technological University; Owen, Robert [Michigan Technological University; Helmig, Detlev [University of Colorado at Boulder

    2014-12-09

    The scientific scope of the project was to exploit the unique location of the Pico Mountain Observatory (PMO) located in the summit caldera of the Pico Volcano in Pico Island in the Azores, for atmospheric studies. The observatory, located at 2225m a.s.l., typically samples free tropospheric aerosols laying above the marine low-level clouds and long-range transported from North America. The broad purpose of this research was to provide the scientific community with a better understanding of fundamental physical processes governing the effects of aerosols on radiative forcing and climate; with the ultimate goal of improving our abilities to understand past climate and to predict future changes through numerical models. The project was 'exploratory' in nature, with the plan to demonstrate the feasibility of deploying for the first time, an extensive aerosol research package at PMO. One of the primary activities was to test the deployment of these instruments at the site, to collect data during the 2012 summer season, and to further develop the infrastructure and the knowledge for performing novel research at PMO in follow-up longer-term aerosol-cloud studies. In the future, PMO could provide an elevated research outpost to support the renewed DOE effort in the Azores that was intensified in 2013 with the opening of the new sea-level ARM-DOE Eastern North Atlantic permanent facility at Graciosa Island. During the project period, extensive new data sets were collected for the planned 2012 season. Thanks to other synergistic activities and opportunities, data collection was then successfully extended to 2013 and 2014. Highlights of the scientific findings during this project include: a) biomass burning contribute significantly to the aerosol loading in the North Atlantic free troposphere; however, long-range transported black carbon concentrations decreased substantially in the last decade. b) Single black carbon particles – analyzed off-line at the electron

  13. North Atlantic Right Whale Sighting Advisory System (NARWSS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Since 1995, PSB has been conducting line-transect aerial abundance surveys over waters ranging from North Carolina to the Gulf of St. Lawrence in Nova Scotia,...

  14. Passive Acoustic Studies of North Atlantic Right Whales

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Passive acoustic monitoring buoys have been deployed in shallow waters between North Carolina and Northern Florida since 2003. These units are bottom mounted...

  15. Health outcomes among HIV-positive Latinos initiating antiretroviral therapy in North America versus Central and South America

    Directory of Open Access Journals (Sweden)

    Carina Cesar

    2016-03-01

    Full Text Available Introduction: Latinos living with HIV in the Americas share a common ethnic and cultural heritage. In North America, Latinos have a relatively high rate of new HIV infections but lower rates of engagement at all stages of the care continuum, whereas in Latin America antiretroviral therapy (ART services continue to expand to meet treatment needs. In this analysis, we compare HIV treatment outcomes between Latinos receiving ART in North America versus Latin America. Methods: HIV-positive adults initiating ART at Caribbean, Central and South America Network for HIV (CCASAnet sites were compared to Latino patients (based on country of origin or ethnic identity starting treatment at North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD sites in the United States and Canada between 2000 and 2011. Cox proportional hazards models compared mortality, treatment interruption, antiretroviral regimen change, virologic failure and loss to follow-up between cohorts. Results: The study included 8400 CCASAnet and 2786 NA-ACCORD patients initiating ART. CCASAnet patients were younger (median 35 vs. 37 years, more likely to be female (27% vs. 20% and had lower nadir CD4 count (median 148 vs. 195 cells/µL, p<0.001 for all. In multivariable analyses, CCASAnet patients had a higher risk of mortality after ART initiation (adjusted hazard ratio (AHR 1.61; 95% confidence interval (CI: 1.32 to 1.96, particularly during the first year, but a lower hazard of treatment interruption (AHR: 0.46; 95% CI: 0.42 to 0.50, change to second-line ART (AHR: 0.56; 95% CI: 0.51 to 0.62 and virologic failure (AHR: 0.52; 95% CI: 0.48 to 0.57. Conclusions: HIV-positive Latinos initiating ART in Latin America have greater continuity of treatment but are at higher risk of death than Latinos in North America. Factors underlying these differences, such as HIV testing, linkage and access to care, warrant further investigation.

  16. North American Water Program (NAWP): A Vision to Address North America's Freshwater Sustainability Challenges

    Science.gov (United States)

    Belvedere, D. R.; Houser, P. R.; Schiffer, R. A.; Entin, J. K.

    2013-12-01

    Dramatically changing climates has had an indelible impact on North America's water crisis; the rapid melting of glaciers has profound implications for the sustainability of Canada's rivers. However, projective increases in water demand from increasing population, industrial energy, and agriculture needs may have four times more impact on the water supply-demand imbalance than climate change. Reliable prediction of hydrologic change and extremes is of critical importance for policy and decision makers to adapt to these future water challenges. However, the models that we use to understand and forecast water availability, flooding, and drought are simply not up to the task of addressing our most pressing societal issues and national security. We need a decisive and coordinative effort to systematically improve water cycle prediction skill, coupled with reliable methodologies to translate those predictions into actionable water supply and quality information to support sustainable water management - this is a primary motivation for the proposed North American Water Program (NAWP). To decisively address these challenges, we recommend that NAWP coalesce an interdisciplinary, international and interagency effort to make significant contributions to continental-to-decision-scale hydroclimate science and solutions. By entraining, integrating and coordinating the vast array of interdisciplinary observationable and prediction resources available, NAWP will significantly advance skill in predicting, assessing, and managing variability and changes in North American water resources, as an integral part of the global climate system. We adopt three challenges to organize NAWP efforts. The first deals with developing a scientific basis and tools for mitigating and adapting to changes in the water supply-demand balance. The second challenge is benchmarking; to use incomplete and uncertain observations to assess water storage and quality dynamics, and to characterize the

  17. Salt transport in the Subpolar Gyre amplifies North Atlantic climate variability

    Science.gov (United States)

    Born, Andreas; Stocker, Thomas F.; Britt Sandø, Anne

    2016-04-01

    Transport of salt in the Irminger Current, the northern branch of the Atlantic Subpolar Gyre coupling the eastern and western subpolar North Atlantic, plays an important role for climate variability across a wide range of time scales. High-resolution ocean modeling and observations indicate that salinities in the eastern subpolar North Atlantic decrease with enhanced circulation of the North Atlantic subpolar gyre. This has led to the perception that a stronger SPG also transports less salt westward, which would weaken deep convection in the Labrador Sea and thus the gyre itself. In this study, we analyze a regional ocean model and a comprehensive global coupled climate model, and show that a stronger SPG transports more salt in the Irminger Current irrespective of lower salinities in its source region. The additional salt converges in the Labrador Sea and the Irminger Basin by eddy transports, increases surface salinity in the western SPG, and favors more intense deep convection. This is part of a positive feedback mechanism with large implications for climate variability and predictability.

  18. Phylogeography and population dynamics of the white-sided dolphin (Lagenorhynchus acutus) in the North Atlantic

    KAUST Repository

    Banguera-Hinestroza, E.

    2014-02-27

    Highly mobile species in the marine environment may be expected to show little differentiation at the population level, but this is often not the case. Instead cryptic population structure is common, and effective conservation will require an understanding of how these patterns evolve. Here we present an assessment from both sides of the North Atlantic of differentiation among populations of a dolphin species that inhabits mainly pelagic waters, the Atlantic white-sided dolphin. We compare eleven putative populations in the western and eastern North Atlantic at mtDNA and microsatellite DNA loci and find reduced nucleotide diversity and signals for historical bottlenecks and post-bottleneck expansions in all regions. We calculate expansion times to have occurred during the early Holocene, following the last glacial maximum (LGM). We find evidence for connectivity among populations from either side of the North Atlantic, and differentiation between putative populations in the far northeast compared with all other areas sampled. Some data suggest the possibility of separate refugia during the LGM explaining this pattern, although ongoing ecological processes may also be a factor. We discuss the implications for developing effective programs of conservation and management in the context of ongoing anthropogenic impact. © 2014 Springer Science+Business Media Dordrecht.

  19. Low-frequency storminess signal at Bermuda linked to cooling events in the North Atlantic region

    Science.gov (United States)

    Hengstum, Peter J.; Donnelly, Jeffrey P.; Kingston, Andrew W.; Williams, Bruce E.; Scott, David B.; Reinhardt, Eduard G.; Little, Shawna N.; Patterson, William P.

    2015-02-01

    North Atlantic climate archives provide evidence for increased storm activity during the Little Ice Age (150 to 600 calibrated years (cal years) B.P.) and centered at 1700 and 3000 cal years B.P., typically in centennial-scale sedimentary records. Meteorological (tropical versus extratropical storms) and climate forcings of this signal remain poorly understood, although variability in the North Atlantic Oscillation (NAO) or Atlantic Meridional Overturning Circulation (AMOC) are frequently hypothesized to be involved. Here we present records of late Holocene storminess and coastal temperature change from a Bermudian submarine cave that is hydrographically circulated with the coastal ocean. Thermal variability in the cave is documented by stable oxygen isotope values of cave benthic foraminifera, which document a close linkage between regional temperature change and NAO phasing during the late Holocene. However, erosion of terrestrial sediment into the submarine cave provides a "storminess signal" that correlates with higher-latitude storminess archives and broader North Atlantic cooling events. Understanding the driver of this storminess signal will require higher-resolution storm records to disentangle the contribution of tropical versus extratropical cyclones and a better understanding of cyclone activity during hemispheric cooling periods. Most importantly, however, the signal in Bermuda appears more closely correlated with proxy-based evidence for subtle AMOC reductions than NAO phasing.

  20. Lithospheric Signature of Paleorifts in Cratonal Europe and North America

    Science.gov (United States)

    Keller, G. R.; Stephenson, R. A.; Mickus, K. L.

    2002-12-01

    Southwestern North America and Central Europe share many aspects of their Neoproterozoic and Phanerozoic tectonic evolution. In particular, the break-up of late Precambrian supercontinent created the continental blocks called Laurentia and Baltica. Passive margins developed during and after the rifting that formed these continents, and these margins were deformed by Paleozoic orogenies (Appalachian-Ouachita; Caledonian-Variscan respectively). Our group has studied the Ouachita orogeny that affected southern Laurentia for many years and has recently had the opportunity to study Central Europe by participating in several large seismic experiments. The results of the POLONAISE' 97 experiment delineated the rifted margin of Baltica, and we interpret it to be quite similar to crustal models we have developed for the Ouachita margin. For example, the Holy Cross Mountains in southern Poland exposed a crustal block that is similar to the Devil's River uplift in west Texas. The Polish basin contains a thick pre-Permian section similar to that observed along the Ouachita orogenic belt that is overlain by a Permian and younger sequence that is analogous to the Gulf Coast sequence. Both the Variscan orogeny in Central Europe and the Ouachita orogeny appear to be the result of soft collisions that have left the pre-orogenic rifted margins largely intact. In terms of continental tectonics, rifts that do not succeed in breaking a continent apart are sometimes referred to as having "failed". These failed rifts usually are the sites of post-rift sedimentation that contain important records of continental evolution and prolific petroleum resources. During the past 15 years, a number of studies have shown that the modification of the lithosphere (most evidence is actually for the crust) in failed rifts takes on many forms, is highly variable, and is often very substantial. Although semantic arguments are seldom productive, these results call into question any perception that these

  1. Variability of heat and salinity content in the North Atlantic in the last decade

    OpenAIRE

    Ivchenko, V. O.; N. C. Wells; Aleynik, D. L.; Shaw, A. G. P.

    2009-01-01

    The analysis of the heat and salinity contents have been made for the Northern Atlantic for the decade between January 1999 and December 2008. This analysis is based on the Argo profiling data for the upper 2000 m. Basin-averaged values of anomaly of heat (AHC) and anomaly of salinity content (ASC) are robust and stable. The AHC and ASC demonstrate positive trends in the last decade in the upper 2000 m of the North Atlantic. The linear trend of AHC and ASC are (126.43±18.52)&ti...

  2. Multi-decadal uptake of carbon dioxide into subtropical mode water of the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    N. R. Bates

    2011-12-01

    Full Text Available Natural climate variability impacts the multi-decadal uptake of anthropogenic carbon dioxide (Cant into the North Atlantic Ocean subpolar and subtropical gyres. Previous studies have shown that there is significant uptake of CO2 into the subtropical mode water (STMW that forms south of the Gulf Stream in winter and constitutes the dominant upper-ocean water mass in the subtropical gyre of the North Atlantic Ocean. Observations at the Bermuda Atlantic Time-series Study (BATS site near Bermuda show an increase in dissolved inorganic carbon (DIC of +1.51 ± 0.08 μmol kg−1 yr−1 between 1988 and 2011. It is estimated that the sink of CO2 into STMW was 0.985 ± 0.018 Pg C (Pg = 1015 g C between 1988 and 2011 (~70 % of which is due to uptake of Cant. However, the STMW sink of CO2 was strongly coupled to the North Atlantic Oscillation (NAO with large uptake of CO2 into STMW during the 1990s (NAO positive phase. In contrast, uptake of CO2 into STMW was much reduced in the 2000s during the NAO neutral/negative phase. Thus, NAO induced variability of the STMW CO2 sink is important when evaluating multi-decadal changes in North Atlantic Ocean CO2 sinks.

  3. Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

    KAUST Repository

    Chust, Guillem

    2013-09-16

    In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was triggered by sea warming, using Generalized Additive Models. To this end, the population gravity centre of observed data was compared with that of a series of simulation experiments: (i) a model using only climate factors (i.e. niche-based model) to simulate species habitat suitability, (ii) a model using only temporal and spatial terms to reconstruct the population distribution, and (iii) a model using both factors combined, using a subset of observations as independent dataset for validation. Our findings show that only C. finmarchicus had a consistent poleward shift, triggered by sea warming, estimated in 8.1 km per decade in the North Atlantic (16.5 per decade for the northeast), which is substantially lower than previous works at the assemblage level and restricted to the Northeast Atlantic. On the contrary, C. helgolandicus is expanding in all directions, although its northern distribution limit in the North Sea has shifted northward. Calanus glacialis and C. hyperboreus, which have the geographic centres of populations mainly in the NW Atlantic, showed a slight southward shift, probably responding to cool water penetrating southward in the Labrador Current. Our approach, supported by high model accuracy, shows its power in detecting species latitudinal shifts and identifying its causes, since the trend of occurrence observed data is influenced by the sampling frequency, which has progressively concentrated to lower latitudes with time. © 2013 © 2013 International Council for

  4. The role of salinity in the decadal variability of the North Atlantic meridional overturning circulation

    Energy Technology Data Exchange (ETDEWEB)

    Frankignoul, Claude [Universite Pierre et Marie Curie, Paris 6, LOCEAN/IPSL, Paris Cedex 05 (France); Deshayes, Julie; Curry, Ruth [Woods Hole Oceanographic Institution, Woods Hole, MA (United States)

    2009-11-15

    An OGCM hindcast is used to investigate the linkages between North Atlantic Ocean salinity and circulation changes during 1963-2003. The focus is on the eastern subpolar region consisting of the Irminger Sea and the eastern North Atlantic where a careful assessment shows that the simulated interannual to decadal salinity changes in the upper 1,500 m reproduce well those derived from the available record of hydrographic measurements. In the model, the variability of the Atlantic meridional overturning circulation (MOC) is primarily driven by changes in deep water formation taking place in the Irminger Sea and, to a lesser extent, the Labrador Sea. Both are strongly influenced by the North Atlantic Oscillation (NAO). The modeled interannual to decadal salinity changes in the subpolar basins are mostly controlled by circulation-driven anomalies of freshwater flux convergence, although surface salinity restoring to climatology and other boundary fluxes each account for approximately 25% of the variance. The NAO plays an important role: a positive NAO phase is associated with increased precipitation, reduced northward salt transport by the wind-driven intergyre gyre, and increased southward flows of freshwater across the Greenland-Scotland ridge. Since the NAO largely controlled deep convection in the subpolar gyre, fresher waters are found near the sinking region during convective events. This markedly differs from the active influence on the MOC that salinity exerts at decadal and longer timescales in most coupled models. The intensification of the MOC that follows a positive NAO phase by about 2 years does not lead to an increase in the northward salt transport into the subpolar domain at low frequencies because it is cancelled by the concomitant intensification of the subpolar gyre which shifts the subpolar front eastward and reduces the northward salt transport by the North Atlantic Current waters. This differs again from most coupled models, where the gyre

  5. Elastic thickness estimates at north east passive margin of North America and its implications

    Indian Academy of Sciences (India)

    R T Ratheesh Kumar; Tanmay K Maji; Suresh Ch Kandpal; D Sengupta; Rajesh R Nair

    2011-06-01

    Global estimates of the elastic thickness (Te) of the structure of passive continental margins show wide and varying results owing to the use of different methodologies. Earlier estimates of the elastic thickness of the North Atlantic passive continental margins that used flexural modelling yielded a Te value of ∼20–100 km. Here, we compare these estimates with the Te value obtained using orthonormalized Hermite multitaper recovered isostatic coherence functions. We discuss how Te is correlated with heat flow distribution and depth of necking. The E–W segment in the southern study region comprising Nova Scotia and the Southern Grand Banks show low Te values, while the zones comprising the NE–SW zones, viz., Western Greenland, Labrador, Orphan Basin and the Northern Grand Bank show comparatively high Te values. As expected, Te broadly reflects the depth of the 200–400°C isotherm below the weak surface sediment layer at the time of loading, and at the margins most of the loading occurred during rifting. We infer that these low Te measurements indicate Te frozen into the lithosphere. This could be due to the passive nature of the margin when the loads were emplaced during the continental break-up process at high temperature gradients.

  6. Hydrographic changes in the subpolar North Atlantic at the MCA to LIA transition

    Science.gov (United States)

    Divine, Dmitry; Miettinen, Arto; Husum, Katrine; Koc, Nalan

    2016-04-01

    A network of four marine sediment cores from the northern North Atlantic is used to study hydrographic changes in surface water masses during the last 2000 years with a special focus on the Medieval Climate Anomaly (MCA) to the Little Ice Age (LIA) transition. Three of the cores are recovered from the sites located on main pathways of warm Atlantic water to the Arctic: M95-2011 (Vøring plateau, Norwegian Sea), Rapid-21 COM and LO-14 (Reykjanes Ridge, south of Iceland). The fourth core MD99-2322 is from the SE Greenland shelf (Denmark Strait), and it is influenced by the cold water outflow from the Arctic. The cores were analyzed continuously for planktonic diatoms with a high decadal to subdecadal temporal resolution. Past changes in the spatial distribution of surface water masses have been studied identifying factors, or typical species compositions, in downcore diatom assemblages. To derive the factors a Q-mode factor analysis has been applied to the extended modern calibration data set of 184 surface sediment samples from the North Atlantic, the Labrador Sea, the Nordic Seas, and Baffin Bay. SSTs have also been reconstructed using transfer functions. Variations of the reconstructed SSTs and loadings of major contributing factors reveal a complex regional pattern of changes in the structure of circulation during the MCA/LIA transition (1200-1400 AD). In the Norwegian Sea, the factors associated with assemblages typical for warmer and saline North Atlantic waters are partly displaced by colder and fresher water dwelling diatoms suggesting an eastward migration of mixed Arctic/Atlantic water masses into the Norwegian Sea. The two cores south of Iceland show a westward propagation of a warm water pulse as evidenced by the dominance of assemblages, which today are typical for the waters ca 5° further south than the current study sites. At the SE Greenland shelf an abrupt shift (ca. 50 years) in factors associated with different sea ice zone dwelling diatoms

  7. Correlation of the Late Pleistocene Usselo Horizon (Europe) and the Clovis Layer (North America)

    Science.gov (United States)

    Kloosterman, J. B.

    2007-05-01

    those of the Irish elk, the cave bear, and cave lion. Recently, Richard Firestone and Allen West in North America have carried out an intensive field and laboratory investigation, suspecting an extraterrestrial cause for the extinctions and the cultural discontinuity, with the Clovis layer as the extinction layer, an all-important witness to the catastrophe. They achieved positive results, the most spectacular one perhaps being the iridium content, because that element became well-known in the 1980s as an impact indicator in the K-T boundary layer. Other results include the presence of glass-like carbon, magnetic microspherules, and high levels of potassium-40. Being aware of the similarities in the Late Pleistocene stratigraphical records of Europe and North America, I contacted Firestone and West in 2005, and early in 2006 I sent them samples of the Usselo Horizon from Lommel, Belgium. The analyses they carried out yielded high levels of impact indicators, including magnetic grains, metallic spherules, carbon glass, charcoal, and in the magnetic fraction, high iridium content. These findings largely confirm the identity of the two ET impact layers on either side of the Atlantic Ocean. Hijszeler(1957) Geol.Mijnb.NS 19: 288-302. Haynes and Hemmings (1968) Science 159: 186-7. Wolbach, et al. (1985) Science 230: 167-170. Kloosterman (1999) Symp. New Scenarios of Solar System Evolution, Univ.Bergamo. (Abstract 2002). Kloosterman (2000) De Laag van Usselo, de Wereldbrand en de Verdwijntruc. Bres 201: 63-74. Kloosterman (2006) "De Komeetinslag van 13.000 jaar geleden." Frontier Mag. 12/1: 44- 45. Firestone, et al. (2006) The Cycle of Cosmic Catastrophes. Bear and Co., Rochester, Vermont.

  8. EXPANDING GEOGRAPHICAL RANGE OF CACTOBLASTIS CACTORUM (LEPIDOPTERA: PYRALIDAE) IN NORTH AMERICA

    Science.gov (United States)

    Observational surveys and virgin female-baited traps have identified the continued spread of the cactus moth, Cactoblastis cactorum, along the Atlantic and Gulf Coasts of the United States. The moth is infesting native and ornamental cacti north to Charleston, SC and west to St. George Island, FL. ...

  9. The mechanisms of North Atlantic CO2 uptake in a large Earth System Model ensemble

    Science.gov (United States)

    Halloran, P. R.; Booth, B. B. B.; Jones, C. D.; Lambert, F. H.; McNeall, D. J.; Totterdell, I. J.; Völker, C.

    2015-07-01

    The oceans currently take up around a quarter of the carbon dioxide (CO2) emitted by human activity. While stored in the ocean, this CO2 is not influencing Earth's radiation budget; the ocean CO2 sink therefore plays an important role in mitigating global warming. CO2 uptake by the oceans is heterogeneous, with the subpolar North Atlantic being the strongest CO2 sink region. Observations over the last 2 decades have indicated that CO2 uptake by the subpolar North Atlantic sink can vary rapidly. Given the importance of this sink and its apparent variability, it is critical that we understand the mechanisms behind its operation. Here we explore the combined natural and anthropogenic subpolar North Atlantic CO2 uptake across a large ensemble of Earth System Model simulations, and find that models show a peak in sink strength around the middle of the century after which CO2 uptake begins to decline. We identify different drivers of change on interannual and multidecadal timescales. Short-term variability appears to be driven by fluctuations in regional seawater temperature and alkalinity, whereas the longer-term evolution throughout the coming century is largely occurring through a counterintuitive response to rising atmospheric CO2 concentrations. At high atmospheric CO2 concentrations the contrasting Revelle factors between the low latitude water and the subpolar gyre, combined with the transport of surface waters from the low latitudes to the subpolar gyre, means that the subpolar CO2 uptake capacity is largely satisfied from its southern boundary rather than through air-sea CO2 flux. Our findings indicate that: (i) we can explain the mechanisms of subpolar North Atlantic CO2 uptake variability across a broad range of Earth System Models; (ii) a focus on understanding the mechanisms behind contemporary variability may not directly tell us about how the sink will change in the future; (iii) to identify long-term change in the North Atlantic CO2 sink we should focus

  10. Trends of anthropogenic CO2 storage in North Atlantic water masses

    Directory of Open Access Journals (Sweden)

    P. Lherminier

    2010-01-01

    Full Text Available A high-quality inorganic carbon system database spanning over three decades (1981–2006 and comprising 13 cruises has allowed applying the φCT° method and coming up with accurate estimates of the anthropogenic CO2 (Cant stored in the main water masses of the North Atlantic. In the studied region, strong convective processes convey surface properties, like Cant, into deeper ocean layers and confer this region an added oceanographic interest from the point of view of air-sea CO2 exchanges. Commonly, a tendency for decreasing Cant storage rates towards the deep layers has been observed. In the Iberian Basin, the deep waters (North Atlantic Deep Water have low Cant values and negligible Cant storage rates, while the North Atlantic Central Water in the upper layers shows the largest Cant concentrations and capacity to increase its storage on a yearly basis (1.13±0.14 μmol kg−1 yr−1. This unmatched Cant storage capacity of the warm upper limb of the Meridional Overturning Circulation weakens towards the Irminger basin (0.68±0.06 μmol kg−1 yr−1 due to the lowering of the buffering capacity. The mid and deep waters in the Irminger Sea show rather homogeneous Cant storage rates (between 0.33 and 0.45 μmol kg−1 yr−1, whereas in the Iceland basin these layers seem to have been less affected by Cant. The Cant storage rates in the study region during the 1991–1997 high NAO (North Atlantic Oscillation phase are ~48% higher than during the 1997–2006 low NAO phase that followed. This result suggests that a net decrease in the strength of the North Atlantic sink of atmospheric CO2has taken place during the present decade. The changes in deep-water ventilation together with a detrimental renewal of the main water masses are likely the main driving processes causing this weakening of the North Atlantic CO2sink.

  11. CLIMATIC IMPLICATIONS OF THE FRESH WATER EXPANSION IN THE GREENLAND SEA AND THE NORTH ATLANTIC

    Directory of Open Access Journals (Sweden)

    A. V. Popov

    2012-01-01

    Full Text Available In second part of XX century there are three valuable salinity anomalies in North Atlantic, so-called «The Great Salinity Anomaly» (GSA, which can be characterized as a large, near-surface pool of fresher water [31–33, 36, 37]. There are GSA’70s, GSA’80s and GSA’90s. Dickson [37] described this event as one of dramatic and prolonged changes in ocean’s climate in XX century. In this paper, we have shown genesis of GSA’70s connected with ice production in Arctic flaw leads. Formation of GSAs’ in 1980s and 1990s has, at least, two main reasons. First is fresh water pools and huge amounts of ice carried out fromArcticBasin. The second one is recirculation of previous salinity anomaly inSubarcticBasin. Phenomenological model of climate change formation in polar and subpolar zone of North Hemisphere is presented in the paper. Examination conditions of previous GSA’s appearance and analysis of valuable fresh water intrusions in North Atlantic allow us to conclude that conditions for GSA’2010s are formed already and started to propagate inNorth Atlantic. For the first time we described GSA during its appearance, not post factum. Thus, we are standing at the break point of relatively long cooling inArctic.

  12. A spatially explicit estimate of the prewhaling abundance of the endangered North Atlantic right whale.

    Science.gov (United States)

    Monsarrat, Sophie; Pennino, M Grazia; Smith, Tim D; Reeves, Randall R; Meynard, Christine N; Kaplan, David M; Rodrigues, Ana S L

    2016-08-01

    The North Atlantic right whale (NARW) (Eubalaena glacialis) is one of the world's most threatened whales. It came close to extinction after nearly a millennium of exploitation and currently persists as a population of only approximately 500 individuals. Setting appropriate conservation targets for this species requires an understanding of its historical population size, as a baseline for measuring levels of depletion and progress toward recovery. This is made difficult by the scarcity of records over this species' long whaling history. We sought to estimate the preexploitation population size of the North Atlantic right whale and understand how this species was distributed across its range. We used a spatially explicit data set on historical catches of North Pacific right whales (NPRWs) (Eubalaena japonica) to model the relationship between right whale relative density and the environment during the summer feeding season. Assuming the 2 right whale species select similar environments, we projected this model to the North Atlantic to predict how the relative abundance of NARWs varied across their range. We calibrated these relative abundances with estimates of the NPRW total prewhaling population size to obtain high and low estimates for the overall NARW population size prior to exploitation. The model predicted 9,075-21,328 right whales in the North Atlantic. The current NARW population is thus recovery. According to the model, in June-September NARWs concentrated in 2 main feeding areas: east of the Grand Banks of Newfoundland and in the Norwegian Sea. These 2 areas may become important in the future as feeding grounds and may already be used more regularly by this endangered species than is thought. PMID:26632250

  13. Recent changes in the surface salinity of the North Atlantic subpolar gyre

    Science.gov (United States)

    Reverdin, Gilles; Durand, Fabien; Mortensen, John; Schott, F.; Valdimarsson, H.; Zenk, W.

    2002-12-01

    Sea surface salinity (SSS) was measured since 1896 along 60°N between Greenland and the North Sea and since 1993 between Iceland and Newfoundland. Along 60°N away from the shelves, and north of 53°N, the amplitude of the seasonal cycle is comparable to or less than interannual variability. In these parts of the North Atlantic subpolar gyre, large-scale deviations from the seasonal cycle correlate from one season to the next. This suggests that in these regions, summer and autumn surface data are useful for monitoring changes in upper ocean salinity best diagnosed from less common winter surface data. Further south near the subarctic front, the Labrador Current or near shelves where seasonal variability is strong, this is not the case. Along 60°N, the multiannual low-frequency variability is well correlated across the basin and exhibits fresher surface water since the mid 1970s than in the late 1920s to 1960s. SSS in the Irminger Sea along 60°N lags by 1-year SSS farther east in the Iceland Basin. Variability between Iceland and Newfoundland within the Irminger Sea north of 54°N presents similar characteristics to what is observed along 60°N. Variability near the northwest corner of the North Atlantic Current (52°N/45°W) is larger and is not correlated to what is found further north. Maps of SSS were constructed for a few recent seasons between July 1996 and June 2000, which illustrate the fresh conditions found usually during that period across the whole North Atlantic subpolar gyre, although this includes an episode of higher salinity. The SSS anomaly maps have large uncertainties but suggest that the highest SSS occurred before the spring of 1998 in the Iceland Basin, and after that, in the Irminger Sea. This is followed by fresher conditions, first in the Labrador and Iceland Basin, reaching recently the Irminger Sea.

  14. Holocene relative sea-level changes from North America and the Caribbean

    Science.gov (United States)

    Horton, Benjamin; Engelhart, Simon; Vacchi, Matteo; Khan, Nicole; Peltier, Dick; Roy, Keven

    2014-05-01

    Reconstructions of Holocene relative sea level (RSL) are important for identifying the ice equivalent meltwater contribution to sea-level change during deglaciation. Holocene RSL reconstructions from near, intermediate and far field regions enable the assessment of earth and ice parameters of Glacial Isostatic Adjustment (GIA) models. RSL reconstructions provide data for estimating rates of spatially variable and ongoing vertical land motion; a requirement for understanding the variation in modern and late Holocene sea level as recorded by instrumental and proxy records. Here we explain the methodology employed to reconstruct former sea levels, which follows the practice of the International Geoscience Programme (IGCP). We produce sea level index points from the Pacific and Atlantic coasts of North America and the Caribbean. Index points are defined as the most reliable observations of former sea levels. They consist of an estimate of X (age) and Y (the position of former RSL). Where a suite of index points are developed for a locality or region, they describe changes in RSL through time and estimate rates of change. A valid index point must meet the following four criteria; (1) location of the sample is known; (2) the altitude of the sample (and the error associated with measuring that altitude) is known; (3) the indicative meaning (the relationship between the sample and a tide level) is estimated; and (4) the age of the sample, which is commonly radiocarbon dated is calibrated to sidereal years using the latest calibration curves. In total databases have over 2000 sea-level index points from formerly ice covered, uplifting regions of Canada, to the region of forebulge collapse along the subsiding mid-Atlantic and mid-Pacific coastlines of the United States, to the tropical regions of the Caribbean. Recent analyses of these new published databases have led to a further refinement of the most recent of the ICE-NG (VMX) series of global models of GIA. The records

  15. Year aridity index patterns in northwest China and the relationship to summer North Atlantic sea surface temperature

    Institute of Scientific and Technical Information of China (English)

    YAN Yan; ZHAO Xinyi; ZHOU Liping

    2008-01-01

    Aim to linking the variability of drought in northwest China to the oceanic influence of North Atlantic SSTs at the background of global warming and at the regional climate change shifting stages, year aridity index variations in northwest China and summer North Atlantic sea surface temperature (SST) variations are examined for the 44 a period of 1961--2004 using singular value de-composition (SVD) analysis. Results show that the SST anomalies (SSTA) in the North Atlantic in summer reflected three basic models. The first SVD mode of SST pattern shows a dipole - like variation with the positive center located at southwest and nega-tive center at northeast of extratropical North Atlantic. And it strongly relates to the positive trend in AI variation in northwest China. The second coupled modes display the coherent positive anomalies in extratropical North Atlantic SST and the marked opposite trend of AI variability between north and south of Xinjiang. In addition, the lag correlation analysis of the first mode of SSTA and geopotential heights at 500 hPa variations also shows that the indication of the former influencing the latter configuration, which re-sult in higher air temperature and less precipitation when the SSTA in the North Atlantic Ocean in summer motivated Eurasian cir-culation of EA pattern, further to influence the wet - dry variations in northwest China by the ocean-to - atmosphere forcing.

  16. A Reassessment of the Integrated Impact of Tropical Cyclones on Surface Chlorophyll in the Western Subtropical North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Foltz, Gregory R.; Balaguru, Karthik; Leung, Lai-Yung R.

    2015-02-28

    The impact of tropical cyclones on surface chlorophyll concentration is assessed in the western subtropical North Atlantic Ocean during 1998–2011. Previous studies in this area focused on individual cyclones and gave mixed results regarding the importance of tropical cyclone-induced mixing for changes in surface chlorophyll. Using a more integrated and comprehensive approach that includes quantification of cyclone-induced changes in mixed layer depth, here it is shown that accumulated cyclone energy explains 22% of the interannual variability in seasonally-averaged (June–November) chlorophyll concentration in the western subtropical North Atlantic, after removing the influence of the North Atlantic Oscillation (NAO). The variance explained by tropical cyclones is thus about 70% of that explained by the NAO, which has well-known impacts in this region. It is therefore likely that tropical cyclones contribute significantly to interannual variations of primary productivity in the western subtropical North Atlantic during the hurricane season.

  17. Historical North Atlantic Hurricane Tracks - Major Storms with Landfall in the United States, 1851-2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This Historical North Atlantic Hurricane Tracks file of major storms with landfall in the United States contains the six-hourly (0000, 0600, 1200, 1800 UTC) center...

  18. WATER TEMPERATURE and Other Data from ATLANTIS II From North Atlantic Ocean from 19791017 to 19791102 (NODC Accession 8600043)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Helium and Tritium data from the North Atlantic ocean was submitted by Dr. William Jenkins from Woods Hole Oceanographic Institution (WHOI). The data were collected...

  19. Coral Research Data from NOAA's Undersea Research Center, North Atlantic and Great Lakes Region, NOAA's Undersea Research Program (NURP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's Undersea Research Center for the NOAA's Undersea Research Center for the North Atlantic and Great Lakes region (NAGL) explores and studies the waters off the...

  20. Tropical Cyclone Exposure for U.S. waters within the North Atlantic Ocean basin, 1900-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent modeled, historical exposure of U.S. offshore and coastal waters to tropical cyclone activity within the North Atlantic Ocean basin. BOEM Outer...

  1. Inverted Barometer Contributions to Accelerated and Extreme Annual Mean Sea Level Changes Along the East Coast of North America

    Science.gov (United States)

    Piecuch, C. G.; Ponte, R. M.

    2015-12-01

    Recent works have interpreted accelerated and extreme sea level (SL) changes along the northeast coast of North America primarily in terms of dynamic changes related to the meridional overturning or coastal circulations. Isostatic changes related to surface atmospheric pressure loading —the inverted barometer (IB) effect— have been deemed relatively unimportant, but a comprehensive analysis of the IB effect has been lacking. In this work, we use five different atmospheric pressure products to analyze the influence of the IB effect on annual mean SL from tide gauge records. Consistently across all products, the IB effect accounts for about 50% of the magnitude of a recent extreme event of SL rise in 2009 along Atlantic Canada and New England. In fact, the unique nature of the event was largely a result of the extreme IB signal. Estimated IB effects also amount to about 10-30% of recent multidecadal SL accelerations over the Mid-Atlantic Bight and Southern New England. These findings reiterate the need for careful estimation of IB effects for studies that want to interpret observed SL in terms of dynamic ocean circulation changes.

  2. Vertical density gradient in the eastern North Atlantic during the last 30,000 years

    Energy Technology Data Exchange (ETDEWEB)

    Rogerson, M.; Ramirez, J. [University of Hull, Geography Department, Hull (United Kingdom); Bigg, G.R. [University of Sheffield, Department of Geography, Sheffield (United Kingdom); Rohling, E.J. [University of Southampton, National Oceanography Centre, School of Ocean and Earth Science, Southampton (United Kingdom)

    2012-08-15

    Past changes in the density and momentum structure of oceanic circulation are an important aspect of changes in the Atlantic Meridional Overturning Circulation and consequently climate. However, very little is known about past changes in the vertical density structure of the ocean, even very extensively studied systems such as the North Atlantic. Here we exploit the physical controls on the settling depth of the dense Mediterranean water plume derived from the Strait of Gibraltar to obtain the first robust, observations-based, probabilistic reconstruction of the vertical density gradient in the eastern North Atlantic during the last 30,000 years. We find that this gradient was weakened by more than 50%, relative to the present, during the last Glacial Maximum, and that changes in general are associated with reductions in AMOC intensity. However, we find only a small change during Heinrich Event 1 relative to the Last Glacial Maximum, despite strong evidence that overturning was substantially altered. This implies that millennial-scale changes may not be reflected in vertical density structure of the ocean, which may be limited to responses on an ocean-overturning timescale or longer. Regardless, our novel reconstruction of Atlantic density structure can be used as the basis for a dynamical measure for validation of model-based AMOC reconstructions. In addition, our general approach is transferrable to other marginal sea outflow plumes, to provide estimates of oceanic vertical density gradients in other locations. (orig.)

  3. Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

    Science.gov (United States)

    Li, Xichen; Holland, David M; Gerber, Edwin P; Yoo, Changhyun

    2014-01-23

    In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution. Antarctic climate is influenced by, among other factors, changes in radiative forcing and remote Pacific climate variability, but none explains the observed Antarctic Peninsula warming or the sea-ice redistribution in austral winter. However, in the north and tropical Atlantic Ocean, the Atlantic Multidecadal Oscillation (a leading mode of sea surface temperature variability) has been overlooked in this context. Here we show that sea surface warming related to the Atlantic Multidecadal Oscillation reduces the surface pressure in the Amundsen Sea and contributes to the observed dipole-like sea-ice redistribution between the Ross and Amundsen-Bellingshausen-Weddell seas and to the Antarctic Peninsula warming. Support for these findings comes from analysis of observational and reanalysis data, and independently from both comprehensive and idealized atmospheric model simulations. We suggest that the north and tropical Atlantic is important for projections of future climate change in Antarctica, and has the potential to affect the global thermohaline circulation and sea-level change. PMID:24451542

  4. Reconstructing Hydrologic Variability in Southwestern North America Using Speleothem Proxies and Precipitation Isotopes from California

    Science.gov (United States)

    McCabe-Glynn, Staryl

    Precipitation in southwestern North America has exhibited significant natural variability over the past few thousand years. This variability has been attributed to sea surface temperature regimes in the Pacific and Atlantic oceans, and to the attendant shifts in atmospheric circulation patterns. In particular, decadal variability in the North Pacific has influenced precipitation in this region during the twentieth century, but links to earlier droughts and pluvials are unclear. Here I assess these links using delta18 O measurements from a speleothem from southern California that spans AD 854-- 2007. I show that variations in the oxygen isotopes of the speleothem correlate to sea surface temperatures in the Kuroshio Extension region of the North Pacific, which affect the atmospheric trajectory and isotopic composition of moisture reaching the study site. Interpreting our speleothem data as a record of sea surface temperatures in the Kuroshio Extension, I find a strong 22-year periodicity, suggesting a persistent solar influence on North Pacific decadal variability. A comparison with tree-ring records of precipitation during the past millennium shows that some droughts occurred during periods of warmth in the Kuroshio Extension, similar to the instrumental record. However, other droughts did not and instead were likely influenced by other factors. The carbon isotope record indicates drier conditions are associated with higher delta13C values and may be a suitable proxy for reconstructing past drought variability. More research is needed to determine the controls on trace element concentrations. Finally, I find a significant increase in sea surface temperature variability over the past 150 years, which may reflect an influence of greenhouse gas concentrations on variability in the North Pacific. While drought is a common feature of climate in this region, most climate models also project extreme precipitation events to increase in frequency and severity because the

  5. NORTH ATLANTIC OSCILLATION AND RAINFALL VARIABILITY ON THE SOUTHERN COAST OF THE MEDITERRANEAN

    Directory of Open Access Journals (Sweden)

    BENOIT L.

    2014-03-01

    Full Text Available Regions of the south-western Mediterranean basin were the focus of many studies since they have experienced a series of climate changes. The contribution of the North Atlantic Oscillation in precipitations is required to be analyzed with the aim to understand the possible hydrological changes. In this way, an analysis of precipitations along the coast of central Maghreb (Morocco, Algeria and Tunisia was carried. The present analysis was performed using (1 The graphical method of information processing and (2 wavelet transform technique. Results can be summarized as the following. Results show a high drought observed in all studied regions since the med-eighties and a return of the wet period since year 2003. Moreover, we demonstrate significant links of precipitations with the North Atlantic Oscillation

  6. Environmental radioactivity in the North Atlantic region. The Faroe Islands and Greenland included. 1984

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90 and cesium-137 was determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes) and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in human diet in the Faroes and Greenland in 1984. Results from samplings of surface sea water and seaweed in the Norwegian and Greenland Seas and along the Norwegian and Greenland west coasts are reported. Beside radiocesium and 90Sr some of these samples have also been anlysed for tritium, polonium, plutonium and americium. Finally technetium-99 data on seaweed samples collected in the North Atlantic region since the beginning of the sixties are presented. (author)

  7. Environmental radioactivity in the North Atlantic region. The Faroe Islands and Greenland included. 1985

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90 and cesium-137 was determined in samples of precipitation, sea water vegetation, various foodstuffs (including milk in the Faroes) and drinking water. Estimates are given of the mean contents of 90Sr a 137Cs in human diet in the Faroes and Greenland in 1985. Results from samplings of surface sea water and seaweed in the English Channel, the Fram Strait and along the Norwegian and Greenland coast are reported. Beside radiocesium and 90Sr some of these samples have also been analysed for tritium, plutonium and americium. Finally technetium-99 data on seaweed and sea water samples collected in the North Atlantic region are presented. 14 refs. (author)

  8. Environmental radioactivity in the North Atlantic region. The Faroe Islands and Greenland included. 1983

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in the North Atlantic region including the Faroe Islands and Greenland are reported. Strontium-90 and cesium-137 was determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes) and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in human diet in the Faroes and Greenland in 1983. Results from samplings of surface sea water and seaweed in the Norwegian and Greenland Seas and along the Norwegian and Greenland west coasts are reported. Beside radiocesium and 90Sr some of these samples have also been anlysed for tritium,plutonium and americium. Finally technetium-99 data on seaweed samples collected in the North Atlantic region since the beginning of the sixties are presented. (author)

  9. How the Subpolar gyre strength influences phytoplankton blooms dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Payne, Mark; MacKenzie, Brian;

    2012-01-01

    , including early life stages of commercial fish species. We assess NASPG strength effect on North Atlantic phytoplankton bloom dynamics. We analyse time‐series (from 1998 to 2010) of chlorophyll a (Chl a, from the Globcolour project) annual anomaly as a proxy of phytoplankton abundance, and of sea surface......Changes in the North Atlantic Subpolar gyre (NASPG) have been linked to the interannual variability of primary production. However, little is known about the mechanisms behind both environmental processes, and how the NASPG strength may extend its potential impacts to higher trophic levels...... anomaly in chlorophyll concentrations and the gyre index was found for the southern region (region 3). Indications of a strong influence of NASPG index are related to areas within the gyre, which may have an impact in the ecosystem functioning. The results also suggest that physical forcing other than the...

  10. On the changes in number and intensity of North Atlantic tropical cyclones

    CERN Document Server

    Briggs, W M

    2007-01-01

    Bayesian statistical models were developed for the number of tropical cyclones and the rate at which these cyclones became hurricanes in the North Atlantic. We find that, controlling for the cold tongue index and the North Atlantic oscillation index, there is high probability that the number of cyclones has increased in the past thirty years; but the rate at which these storms become hurricanes appears to be constant. We also investigate storm intensity by measuring the distribution of individual storm lifetime in days, storm track length, and Emanuel's power dissiptation index. We find little evidence that the distribution of individual storm intensity is changing through time. Any increase in cumulative yearly storm intensity and potential destructiveness, therefore, is due to the increasing number of storms and not due to any increase in the intensity of individual storms.

  11. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Hall

    Full Text Available Wild waterfowl are primary reservoirs of avian influenza viruses (AIV. However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61% in these sea duck populations but low virus prevalence (0.3%. Using these data we estimated that an antibody half-life of 141 weeks (3.2 years would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  12. Avian influenza ecology in North Atlantic sea ducks: Not all ducks are created equal

    Science.gov (United States)

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J Christian; Soos, Catherine; Dusek, Robert; Allen, R. Bradford; Nashold, Sean W.; Teslaa, Joshua L.; Jónsson, Jón Einar; Ballard, Jennifer R.; Harms, Naomi Jnae; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  13. The role of tropical Atlantic SST anomalies in modulating western North Pacific tropical cyclone genesis

    Science.gov (United States)

    Huo, Liwei; Guo, Pinwen; Hameed, Saji N.; Jin, Dachao

    2015-04-01

    The connection between north tropical Atlantic (NTA) sea surface temperature (SST) anomalies and tropical cyclone (TC) genesis over the western North Pacific (WNP) and associated physical mechanisms are investigated in this study. We demonstrate a remarkable negative correlation of WNP TC genesis frequency with the (preceding) boreal spring NTA SST anomalies. Our analysis suggests that major factors for TC genesis including distributions of large-scale vorticity and midtropospheric humidity are rendered unfavorable by remote teleconnections while barotropic energy conversion from the large-scale flow is suppressed. As shown in recent studies, the remote teleconnection from the Atlantic is sustained and enhanced throughout the typhoon season through local air-sea interactions. These results suggest that boreal spring NTA SST anomaly could be a new predictor for the seasonal WNP TC activity.

  14. Pliocene sea surface temperatures of the north atlantic ocean at 3.0 Ma

    Science.gov (United States)

    Dowsett, H.J.; Poore, R.Z.

    1991-01-01

    Sea-surface temperature (SST) estimates based on quantitative analysis of planktic foraminifer faunas in North Atlantic deep sea cores suggest that high-frequency, low-amplitude variability related to orbital forcing was superimposed on long-term changes that delineate intervals within the Pliocene that were both warmer and cooler than today. SST estimates from several DSDP and ODP sites, as well as land sections, have been combined into a synoptic view of SST during a Pliocene warm interval centered at about 3.0 Ma. The Pliocene North Atlantic warm interval SST estimates show little evidence for warming in tropical regions whereas mid- to high-latitude areas show moderate to strong warming. SST estimates for the last interglacial (Isotope Stage 5e) show a similar pattern, but warming during the last interglacial was not as pronounced as the Middle Pliocene warming. The regional distribution of SST estimates during these past warm events suggests an increase in ocean circulation. ?? 1991.

  15. Mid-2000s North Atlantic shift: Heat budget and circulation changes

    Science.gov (United States)

    Somavilla, R.; González-Pola, C.; Schauer, U.; Budéus, G.

    2016-03-01

    Prior to the 2000s, the North Atlantic was the basin showing the greatest warming. However, since the mid-2000s during the so-called global warming hiatus, large amounts of heat were transferred in this basin from upper to deeper levels while the dominance in terms of atmospheric heat capture moved into the Indo-Pacific. Here we show that a large transformation of modal waters in the eastern North Atlantic (ENA) played a crucial role in such contrasting behavior. First, strong winter mixing in 2005 transformed ENA modal waters into a much saltier, warmer, and denser variety, transferring upper ocean heat and salt gained slowly over time to deeper layers. The new denser waters also altered the zonal dynamic height gradient reversing the southward regional flow and enhancing the access of saltier southern waters to higher latitudes. Then, the excess salinity in northern regions favored additional heat injection through deep convection events in later years.

  16. Mapping tectonic deformation in the crust and upper mantle beneath Europe and the North Atlantic Ocean.

    Science.gov (United States)

    Zhu, Hejun; Tromp, Jeroen

    2013-08-23

    We constructed a three-dimensional azimuthally anisotropic model of Europe and the North Atlantic Ocean based on adjoint seismic tomography. Several features are well correlated with historical tectonic events in this region, such as extension along the North Atlantic Ridge, trench retreat in the Mediterranean, and counterclockwise rotation of the Anatolian Plate. Beneath northeastern Europe, the direction of the fast anisotropic axis follows trends of ancient rift systems older than 350 million years, suggesting "frozen-in" anisotropy related to the formation of the craton. Local anisotropic strength profiles identify the brittle-ductile transitions in lithospheric strength. In continental regions, these profiles also identify the lower crust, characterized by ductile flow. The observed anisotropic fabric is generally consistent with the current surface strain rate measured by geodetic surveys. PMID:23929947

  17. Late Cretaceous restructuring of terrestrial communities facilitated the end-Cretaceous mass extinction in North America

    Science.gov (United States)

    Mitchell, Jonathan S.; Roopnarine, Peter D.; Angielczyk, Kenneth D.

    2012-11-01

    The sudden environmental catastrophe in the wake of the end-Cretaceous asteroid impact had drastic effects that rippled through animal communities. To explore how these effects may have been exacerbated by prior ecological changes, we used a food-web model to simulate the effects of primary productivity disruptions, such as those predicted to result from an asteroid impact, on ten Campanian and seven Maastrichtian terrestrial localities in North America. Our analysis documents that a shift in trophic structure between Campanian and Maastrichtian communities in North America led Maastrichtian communities to experience more secondary extinction at lower levels of primary production shutdown and possess a lower collapse threshold than Campanian communities. Of particular note is the fact that changes in dinosaur richness had a negative impact on the robustness of Maastrichtian ecosystems against environmental perturbations. Therefore, earlier ecological restructuring may have exacerbated the impact and severity of the end-Cretaceous extinction, at least in North America.

  18. The Younger Dryas ET Impact Theory and Terminal Pleistocene Mammalian Extinctions in North America

    Science.gov (United States)

    Erlandson, J. M.; Kennett, D. J.; Kennett, J.; Braje, T.; Culleton, B.

    2007-05-01

    Despite decades of intensive study and debate, no consensus has been reached on what caused the extinction of North America's mammalian megafauna at the end of the Pleistocene. In a scholarly standoff, prominent scientists have shown that neither "human overkill" or "climate change" models adequately account for the patterns found in the paleontological and archaeological records of North America. The Younger Dryas ET Impact theory may dramatically alter this debate, adding a catastrophic trigger to help explain the rapid extinction of many large mammals about 12,900 years ago. New data suggest that an extraterrestrial impact focused in northern and eastern North America may have devastated the megafauna through: (1) direct mortality caused by the impacts shock wave, debris, and massive wildfires; (2) dramatic reduction of terrestrial food supplies, rapid climatic change, and ecological reorganization; and (3) coup-de-grace effects of surviving human populations rapidly expanding after the impact.

  19. Projected hydrogen cost from methane reforming for North America 2015-2050

    International Nuclear Information System (INIS)

    The Hydrogen Futures Simulation Model (H2Sim) was used to project the cost for hydrogen at the point of sale to light duty vehicles for distributed, small-scale steam methane reforming. Projections cover the period from 2010-2050 in North America, and take into account assumptions about the quantity of recoverable natural gas remaining in North America. We conclude that there is a window for distributed reforming to play a positive role in supplying a H2 fuel infrastructure, but this window is closing rapidly. The analysis assumes that production from natural gas reserves in North America will peak sometime before 2050 and demand will cause the price to rise after the peak of production in a manner consistent with Hotelling's model. We consider three scenarios for when the peak occurs, and evaluate the impact on the cost of hydrogen fuel produced via distributed small scale reforming in these three scenarios. (authors)

  20. Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic

    OpenAIRE

    Detlev Helmig; Mauricio Muoz; Jacques Hueber; Claudio Mazzoleni; Lynn Mazzoleni; Owen, Robert C.; Maria Val-Martin; Paulo Fialho; Christian Plass-Duelmer; Palmer, Paul I.; Lewis, Alastair C.; Gabriele Pfister

    2015-01-01

    Abstract A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposp...

  1. Remote Acoustic Monitoring of North Atlantic Right Whales (Eubalaena glacialis) Reveals Seasonal and Diel Variations in Acoustic Behavior

    OpenAIRE

    Matthews, Leanna P.; Jessica A McCordic; Susan E Parks

    2014-01-01

    Remote acoustic monitoring is a non-invasive tool that can be used to study the distribution, behavior, and habitat use of sound-producing species. The North Atlantic right whale (Eubalaena glacialis) is an endangered baleen whale species that produces a variety of stereotyped acoustic signals. One of these signals, the "gunshot" sound, has only been recorded from adult male North Atlantic right whales and is thought to function for reproduction, either as reproductive advertisement for femal...

  2. Report of the Regional Coordination Meeting for the North Atlantic 2014 (RCM NA 2014)

    OpenAIRE

    Rodríguez-Gutiérrez, J. (José); Juárez, A.; ZENNER A.; Harley, B.; J./Elson; Beek, F.; ZARAUZ L.; Mugerza, E.; McCorminck, H.; Reis, D.; Ulleweit, J.; Pout, A. (Alastair); DINTHEER C.; Azevedo, M.; Dias, M.

    2014-01-01

    The 11th RCM North Atlantic was held in Horta (Portugal) 22-26 September 2014. Due to the delayed introduction of the revised DCF the European Commission decided a roll-over in 2013 meaning Member States National Programmes 2011-2013 remains unchanged for the period 2014-2017. The limitations this decision brings for coordination of current MS national programmes have allowed RCM NA to focus in three major different aspects of the data collection where...

  3. Regional-Scale Ozone Deposition to North-East Atlantic Waters

    OpenAIRE

    C. D. O'Dowd; Jennings, S. G.; Tripathi, O. P.; S Varghese; Coleman, L.

    2010-01-01

    A regional climate model is used to evaluate dry deposition of ozone over the North East Atlantic. Results are presented for a deposition scheme accounting for turbulent and chemical enhancement of oceanic ozone deposition and a second non-chemical, parameterised gaseous dry deposition scheme. The first deposition scheme was constrained to account for sea-surface ozone-iodide reactions and the sensitivity of modelled ozone concentrations to oceanic iodide concentration was investigated. Simul...

  4. Impacts of the North Atlantic Oscillation on stream water chemistry in mid-Wales

    OpenAIRE

    L. Ness; Neal, C.; Davies, T.D.; Reynolds, B.

    2002-01-01

    Analysis of winter stream chemistry data from the Afon Hafren in mid-Wales reveals links between stream chemistry and the North Atlantic Oscillation (NAO). K, Y, Al and dissolved organic carbon (DOC) concentrations increase during high NAO index months (relatively warm and wet weather), while Ca, Mg and NO3 concentrations increase during low NAO months (relatively cold and dry conditions) with the increased concentrations lasting int...

  5. Impacts of the North Atlantic Oscillation on stream water chemistry in mid-Wales

    OpenAIRE

    L. Ness; Neal, C.; Davies, T.D.; Reynolds, B.

    2004-01-01

    Analysis of winter stream chemistry data from the Afon Hafren in mid-Wales reveals links between stream chemistry and the North Atlantic Oscillation (NAO). K, Y, Al and dissolved organic carbon (DOC) concentrations increase during high NAO index months (relatively warm and wet weather), while Ca, Mg and NO3 concentrations increase during low NAO months (relatively cold and dry conditions) with the increased concentrations lasting into the next month. The cause of the concentration c...

  6. Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

    Science.gov (United States)

    Gehlen, M.; Séférian, R.; Jones, D. O. B.; Roy, T.; Roth, R.; Barry, J.; Bopp, L.; Doney, S. C.; Dunne, J. P.; Heinze, C.; Joos, F.; Orr, J. C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

    2014-12-01

    This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will experience pH reductions exceeding -0.2 units by 2100. Increased stratification in response to climate change partially alleviates the impact of ocean acidification on deep benthic environments. We report on major pH reductions over the deep North Atlantic seafloor (depth >500 m) and at important deep-sea features, such as seamounts and canyons. By 2100, and under the high CO2 scenario RCP8.5, pH reductions exceeding -0.2 (-0.3) units are projected in close to 23% (~15%) of North Atlantic deep-sea canyons and ~8% (3%) of seamounts - including seamounts proposed as sites of marine protected areas. The spatial pattern of impacts reflects the depth of the pH perturbation and does not scale linearly with atmospheric CO2 concentration. Impacts may cause negative changes of the same magnitude or exceeding the current target of 10% of preservation of marine biomes set by the convention on biological diversity, implying that ocean acidification may offset benefits from conservation/management strategies relying on the regulation of resource exploitation.

  7. Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

    OpenAIRE

    M. Gehlen; Séférian, R.; Jones, D.O.B.; Roy, T; R. Roth; Barry, J.; L. Bopp; Doney, S. C.; Dunne, J.P.; C. Heinze; Joos, F.; Orr, J.C.; Resplandy, L.; Segschneider, J.; Tjiputra, J.

    2014-01-01

    This study aims at evaluating the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCP). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully-coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m dep...

  8. Projection of North Atlantic Oscillation and its effect on tracer transport

    OpenAIRE

    Bacer, Sara; Christoudias, Theodoros; Pozzer, Andrea

    2016-01-01

    The North Atlantic Oscillation (NAO) plays an important role in the climate variability of the Northern Hemisphere with significant consequences on long-range pollutant transport. We investigate the evolution of pollutant transport in the 21st century influenced by the NAO under a global climate change scenario. We use a free-running simulation performed by the ECHAM/MESSy Atmospheric Chemistry (EMAC) model coupled with the ocean general circulation model MPIOM, covering the period from 1950 ...

  9. The mechanisms of North Atlantic CO2 uptake in a large Earth System Model ensemble

    Directory of Open Access Journals (Sweden)

    P. R. Halloran

    2014-10-01

    vary rapidly. Given the importance of this sink and its apparent variability, it is critical that we understand the mechanisms behind its operation. Here we explore subpolar North Atlantic CO2 uptake across a large ensemble of Earth System Model simulations, and find that models show a peak in sink strength around the middle of the century after which CO2 uptake begins to decline. We identify different drivers of change on interannual and multidecadal timescales. Short-term variability appears to be driven by fluctuations in regional seawater temperature and alkalinity, whereas the longer-term evolution throughout the coming century is largely occurring through a counterintuitive response to rising atmospheric CO2 concentrations. At high atmospheric CO2 concentrations the contrasting Ravelle factors between the subtropical and subpolar gyres, combined with the transport of surface waters from the subtropical to subpolar gyre, means that the subpolar CO2 uptake capacity is largely satisfied from its southern boundary rather than through air–sea CO2 flux. Our findings indicate that: (i we can explain the mechanisms of subpolar North Atlantic CO2 uptake variability across a broad range of Earth System Models, (ii a focus on understanding the mechanisms behind contemporary variability may not directly tell us about how the sink will change in the future, (iii to identify long-term change in the North Atlantic CO2 sink we should focus observational resources on monitoring subtropical as well as the subpolar seawater CO2, (iv recent observations of a weakening subpolar North Atlantic CO2 sink suggests that the sink strength is already in long-term decline.

  10. Differential timing of gene expression regulation between leptocephali of North Atlantic eels in the Sargasso Sea

    OpenAIRE

    Bernatchez, Louis; Saint-Cyr, Jérôme; Maes, Gregory E; Kalujnaia, S.; Cramb, Gordon; Castonguay, Martin; Als, Thomas Damm; Hansen, Michael Møller

    2011-01-01

    The unique life-history characteristics of North Atlantic catadromous eels have long intrigued evolutionary biologists, especially with respect to mechanisms that could explain their persistence as two ecologically very similar but reproductively and geographically distinct species. Differential developmental schedules during young larval stages have commonly been hypothesized to represent such a key mechanism. We performed a comparative analysis of gene expression by means of microarray expe...

  11. The Hydromedusae of the Amsterdam Mid North Atlantic Plankton Expedition, 1980 (Coelenterata, Hydrozoa)

    OpenAIRE

    Winkler, J.Th.

    1982-01-01

    A faunistic description is given of the Hydromedusae collected during the 1980 Amsterdam Mid North Atlantic Plankton Expedition. In all, 30 species have been caught during the sampling period April 11-May 2, 1980. Remarks are made on structural details of some of the specimens collected. Latitudinal and vertical distribution patterns are given and data on the abundance of some species are recorded. For several bathypelagic species a faunal boundary is assessed at about 40°N, probably coincidi...

  12. Assessing patterns of hybridization between North Atlantic eels using diagnostic single-nucleotide polymorphisms

    OpenAIRE

    Pujolar, M; Jacobsen, W; Als, D; Frydenberg, J.; Magnussen, E.; Jonsson, B.; Jiang, X.; L. Cheng; Bekkevold, D; Maes, G.E.; Bernatchez, L.; Hansen, M.

    2014-01-01

    The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify species-specific diagnostic single-nucleotide polymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N =159) a...

  13. NORTH ATLANTIC OSCILLATION AND RAINFALL VARIABILITY ON THE SOUTHERN COAST OF THE MEDITERRANEAN

    OpenAIRE

    BENOIT, L; NOUACEUR ZEINEDDINE; TURKI IMEN; JEMAI HIBA; Habib, A; Ellouz, M.

    2014-01-01

    Regions of the south-western Mediterranean basin were the focus of many studies since they have experienced a series of climate changes. The contribution of the North Atlantic Oscillation in precipitations is required to be analyzed with the aim to understand the possible hydrological changes. In this way, an analysis of precipitations along the coast of central Maghreb (Morocco, Algeria and Tunisia) was carried. The present analysis was performed using (1) The graphical method of information...

  14. Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

    DEFF Research Database (Denmark)

    Borrell, Asuncion; Velasquez Vacca, Adriana; Pinela, Ana M.;

    2013-01-01

    In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly......, use of habitat and/or migratory destinations are dissimilar between whales from the two regions and suggest that the North Atlantic population of sperm whales is more structured than traditionally accepted....

  15. Modelling the future biogeography of North Atlantic zooplankton communities in response to climate change

    KAUST Repository

    Villarino, E

    2015-07-02

    Advances in habitat and climate modelling allow us to reduce uncertainties of climate change impacts on species distribution. We evaluated the impacts of future climate change on community structure, diversity, distribution and phenology of 14 copepod species in the North Atlantic. We developed and validated habitat models for key zooplankton species using continuous plankton recorder (CPR) survey data collected at mid latitudes of the North Atlantic. Generalized additive models (GAMs) were applied to relate the occurrence of species to environmental variables. Models were projected to future (2080–2099) environmental conditions using coupled hydroclimatix–biogeochemical models under the Intergovernmental Panel on Climate Change (IPCC) A1B climate scenario, and compared to present (2001–2020) conditions. Our projections indicated that the copepod community is expected to respond substantially to climate change: a mean poleward latitudinal shift of 8.7 km per decade for the overall community with an important species range variation (–15 to 18 km per decade); the species seasonal peak is expected to occur 12–13 d earlier for Calanus finmarchicus and C. hyperboreus; and important changes in community structure are also expected (high species turnover of 43–79% south of the Oceanic Polar Front). The impacts of the change expected by the end of the century under IPCC global warming scenarios on copepods highlight poleward shifts, earlier seasonal peak and changes in biodiversity spatial patterns that might lead to alterations of the future North Atlantic pelagic ecosystem. Our model and projections are supported by a temporal validation undertaken using the North Atlantic climate regime shift that occurred in the 1980s: the habitat model built in the cold period (1970–1986) has been validated in the warm period (1987–2004).

  16. Standardizacija materijalnih sredstava u Severnoatlantskom savezu / Materiel standardization in North Atlantic Treaty Organisation

    Directory of Open Access Journals (Sweden)

    Miroslav Glišić

    2005-11-01

    Full Text Available U radu je prikazan proces standardizacije materijalnih sredstava u Severnoatlantskom savezu kroz sagledavanje njegovog mesta i uloge u okviru zajedničke standardizacije, koja se realizuje radi dostizanja interoperabilnosti između vojnih snaga zemalja uključenih u evroatlantske integracije. / This paper presents a process of materiel standardization in the North Atlantic Treaty Organization through analysis of its place and role in common standardization process that should achieve interoperability between allied forces.

  17. Clock genes in a north Atlantic key zooplankter - Expression during overwintering in a high Arctic fjord

    OpenAIRE

    Häfker, N. Sören; Meyer, Bettina; Teschke, Mathias

    2016-01-01

    The copepod Calanus finmarchicus plays a crucial role in the north Atlantic food web, channelling energy from phytoplankton primary production to higher trophic levels including commercially important fish stocks like herring and cod. The copepod species is spreading northward into the Arctic due to ocean warming. The activity phase of C. finmarchicus in spring/summer is characterized by diel vertical migration, meaning that the animals migrate to surface waters around sunset to feed, and bac...

  18. Cephalopods in the North-Eastern Atlantic: Species, Biogeography, Ecology, explotation and conservation

    OpenAIRE

    Hastie, L. C.; Pierce, G.J.; Jing WANG; Bruno, I. (Isabel); Moreno, A.; Piatkowski, Uwe; Robin, J P

    2009-01-01

    Cephalopods play a significant role in coastal and oceanic ecosystems, both as consumers of invertebrates and small fish and as the prey of some fish, seabirds and marine mammals and other large predators. Approximately 30 species of cephalopod have been recorded in the north-eastern Atlantic and adjacent waters, including 18 teuthid (squid), seven sepiolid (bobtail), three sepiid (cuttlefish) and 10 octopod (octopus) species. A number of these are exploited commercially and support important...

  19. Salinity variability in the North Atlantic through synergetic analysis of Argo floats and satellite altimetry data

    Science.gov (United States)

    Stendardo, Ilaria; Rhein, Monika; Klein, Birgit; Roessler, Achim

    2015-04-01

    Salinity distribution in the North Atlantic is affected by changes in the circulation and freshwater fluxes. Changes in salinity are introduced into the ocean's interior by vertical processes like subduction or convection, and transported along circulation pathways. At a given location and depth, salinity could vary by water mass changes due to changes in the freshwater flux, or by vertical migration of density surfaces caused either by wind-driven changes of ocean ventilation or by thermodynamic processes, like poleward migration of isopycnals as a result of surface warming. Changes in the wind driven circulation with a consequence shift of the subpolar front, that separates the fresher subpolar from the saline subtropical gyre, also have a marked influence on upper ocean salinity in the subpolar North Atlantic. Due to the lack of temporal and spatial resolution of salinity observations, salinity anomalies in the last century could only be studied by 5-year means. Thanks to the Argo program, the temporal and spatial resolution of salinity and temperature profiles since early 2000 have significantly improved, allowing to calculate even monthly means. To further improve temporal and spatial resolution of salinity, Argo profiles are combined with altimetry data and a "Transfer function", the Gravest Empirical Mode (GEM), is calculated. The GEM technique exploits the relationship between T/S profiles and dynamic height in order to parameterize salinity data as a function of dynamic height from the satellite altimetry. This technique gives the opportunity to extend the investigation of the salinity variability, with extremely high temporal (daily) and spatial (1/4°) resolution, back to 1993, the beginning of the altimetry data. This method was tested on several regions of the North Atlantic and it works particularly well for some of them, for example in the regions where the North Atlantic Current plays an important role. Within these regions salinity variability in

  20. The North Atlantic Oscillation, climate change and the ecology of British insects

    OpenAIRE

    Westgarth-Smith, Angus

    2012-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Evidence is accumulating that climate change is having a significant effect on a wide range of organisms spanning the full range of biodiversity found on this planet. This study investigates the ecological role of climate change, the North Atlantic Oscillation (NAO) and habitat change on British insect populations. Despite the NAO having a considerable effect on British weather, the role of t...

  1. Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

    OpenAIRE

    Borrell, Asuncion; Velasquez Vacca, Adriana; Pinela, Ana M.; Kinze, Carl; Lockyer, Christina H.; Vighi, Morgana; Aguilar, Alex

    2013-01-01

    In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential...

  2. GLANAM (Glaciated North Atlantic Margins): A Marie Curie Initial Training Network between Norway, the UK & Denmark

    Science.gov (United States)

    Petter Sejrup, Hans; Oline Hjelstuen, Berit

    2015-04-01

    GLANAM (Glaciated North Atlantic Margins) is an Initial Training Network (ITN) funded under the EU Marie Curie Programme. It comprises 10 research partners from Norway, UK and Denmark, including 7 University research teams, 1 industrial full partner and 2 industrial associate partners. The GLANAM network will employ and train 15 early career researchers (Fellows). The aim of GLANAM is to improve the career prospects and development of young researchers in both the public and private sector within the field of earth science, focusing on North Atlantic glaciated margins. The young scientists will perform multi-disciplinary research and receive training in geophysics, remote sensing, GIS, sedimentology, geomorphology, stratigraphy, geochemistry and numerical modeling through three interconnected work packages that collectively address knowledge gaps related to the large, glacial age, sedimentary depocentres on the North Atlantic margin. The 15 Fellows will work on projects that geographically extend from Ireland in the south to the High Arctic. Filling these gaps will not only result in major new insights regarding glacial age processes on continental margins in general, but will also provide paleoclimate information essential for understanding the role of marine-based ice sheets in the climate system and for the testing of climate models. GLANAM brings together leading European research groups working on glaciated margins in a coordinated and collaborative research and training project. Focusing on the North Atlantic margins, this coordinated approach will lead to a major advance in the understanding of glaciated margins more widely and will fundamentally strengthen European research and build capacity in this field.

  3. Long-term variability of the southern Adriatic circulation in relation to North Atlantic Oscillation

    OpenAIRE

    Shabrang, L.; Menna, M.; C. Pizzi; Lavigne, H.; G. Civitarese; M. Gačić

    2016-01-01

    The interannual variability of the South Adriatic Gyre and its relation to the wind vorticity and the large-scale climatic pattern (North Atlantic Oscillation – NAO) was studied using the time series of satellite altimetric data and ocean surface wind products. The cyclonic circulation observed in the southern Adriatic area was partly sustained by the local wind forcing, as suggested by the positive correlation between the rate of change of the current vorticity and the wind...

  4. Identity construction and maintenance in the North Atlantic c. AD800-1250

    OpenAIRE

    Knight, Dayanna

    2014-01-01

    This study is a multivalent investigation of Scandinavian identity formation and cultural structures within the north Atlantic that looks specifically at the construction and maintenance of island identities circa AD800-1250. This not only includes consideration of the Norse settlers but also the effects of contact between the emerging island cultural identities and continental Europe. In order to do this zones of settlement have been defined to better compare the expansion of medieval Scand...

  5. The meiofauna : macrofauna ratio across the continental slope of the Goban Spur (north-east Atlantic)

    OpenAIRE

    Flach, E.; Van Averbeke, J.; C. H. R. Heip

    1999-01-01

    Meio- and macrofauna density and biomass were estimated at the OMEX-transect across the continental slope of the Goban Spur at water depths ranging from 208 to 4460 m in the north-east Atlantic. A linear increase in the ratio between meio- and macrofauna densities with increasing water depth was found. At the continental shelf meiofauna densities were similar to 50 times higher than macrofauna densities, whereas in the abyss meiofauna densities were more than 1000 times higher. This change in...

  6. Ecological genetics in the North Atlantic: environmental gradients and adaptation at specific loci

    OpenAIRE

    Schmidt, P. S.; Serrão, Ester; Pearson, G A; Riginos, C; Rawson, P D; Hilbish, T. J.; Brawley, S. H.; Trussell, G. C.; Carrington, E; Wethey, D. S.; Grahame, J W; Bonhomme, F.; Rand, D. M.

    2008-01-01

    The North Atlantic intertidal community provides a rich set of organismal and environmental material for the study of ecological genetics. Clearly defined environmental gradients exist at multiple spatial scales: there are broad latitudinal trends in temperature, meso-scale changes in salinity along estuaries, and smaller scale gradients in desiccation and temperature spanning the intertidal range. The geology and geography of the American and European coasts provide natural replication of th...

  7. Simulated North Atlantic-Nordic Seas water mass exchanges in an isopycnic coordinate OGCM

    OpenAIRE

    Nilsen, Jan Even Øie; Gao, Yongqi; Drange, Helge; Furevik, Tore; Bentsen, Mats

    2003-01-01

    The variability in the volume exchanges between the North Atlantic and the Nordic Seas during the last 50 years is investigated using a synoptic forced, global version of the Miami Isopycnic Coordinate Ocean Model (MICOM). The simulated volume fluxes agree with the existing observations. The net volume flux across the Faroe-Shetland Channel (FSC) is positively correlated with the net flux through the Denmark Strait (DS; R = 0.74 for 3 years low pass filtering), but negatively correlated with ...

  8. Spatial patterns of North Atlantic Oscillation influence on mass balance variability of European glaciers

    OpenAIRE

    Marzeion, B.; A. Nesje

    2012-01-01

    We present and validate a set of minimal models of glacier mass balance variability. The most skillful model is then applied to reconstruct 7735 individual time series of mass balance variability for all glaciers in the European Alps and Scandinavia. Subsequently, we investigate the influence of atmospheric variability associated with the North Atlantic Oscillation (NAO) on the glaciers' mass balances.

    We find a spatial coherence in the glaciers' sensitivity to NA...

  9. Seasonal phytoplankton blooms in the North Atlantic linked to the overwintering strategies of copepods

    OpenAIRE

    Friedland, Kevin D.; Record, Nicholas R.; Asch, Rebecca G.; Trond Kristiansen; Saba, Vincent S; Drinkwater, Kenneth F.; Stephanie Henson; Leaf, Robert T.; Ryan E. Morse; Johns, David G.; Large, Scott I.; Hjøllo, Solfrid S.; Nye, Janet A.; Mike A. Alexander; Rubao Ji

    2016-01-01

    Abstract The North Atlantic Ocean contains diverse patterns of seasonal phytoplankton blooms with distinct internal dynamics. We analyzed blooms using remotely-sensed chlorophyll a concentration data and change point statistics. The first bloom of the year began during spring at low latitudes and later in summer at higher latitudes. In regions where spring blooms occurred at high frequency (i.e., proportion of years that a bloom was detected), there was a negative correlation between bloom ti...

  10. Latitudinal variation in virus-induced mortality of phytoplankton across the North Atlantic Ocean.

    Science.gov (United States)

    Mojica, Kristina D A; Huisman, Jef; Wilhelm, Steven W; Brussaard, Corina P D

    2016-02-01

    Viral lysis of phytoplankton constrains marine primary production, food web dynamics and biogeochemical cycles in the ocean. Yet, little is known about the biogeographical distribution of viral lysis rates across the global ocean. To address this, we investigated phytoplankton group-specific viral lysis rates along a latitudinal gradient within the North Atlantic Ocean. The data show large-scale distribution patterns of different virus groups across the North Atlantic that are associated with the biogeographical distributions of their potential microbial hosts. Average virus-mediated lysis rates of the picocyanobacteria Prochlorococcus and Synechococcus were lower than those of the picoeukaryotic and nanoeukaryotic phytoplankton (that is, 0.14 per day compared with 0.19 and 0.23 per day, respectively). Total phytoplankton mortality (virus plus grazer-mediated) was comparable to the gross growth rate, demonstrating high turnover rates of phytoplankton populations. Virus-induced mortality was an important loss process at low and mid latitudes, whereas phytoplankton mortality was dominated by microzooplankton grazing at higher latitudes (>56°N). This shift from a viral-lysis-dominated to a grazing-dominated phytoplankton community was associated with a decrease in temperature and salinity, and the decrease in viral lysis rates was also associated with increased vertical mixing at higher latitudes. Ocean-climate models predict that surface warming will lead to an expansion of the stratified and oligotrophic regions of the world's oceans. Our findings suggest that these future shifts in the regional climate of the ocean surface layer are likely to increase the contribution of viral lysis to phytoplankton mortality in the higher-latitude waters of the North Atlantic, which may potentially reduce transfer of matter and energy up the food chain and thus affect the capacity of the northern North Atlantic to act as a long-term sink for CO2. PMID:26262815

  11. Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

    OpenAIRE

    Andersson, C.; F. S. R. Pausata; E. Jansen; Risebrobakken, B.; Telford, R J

    2010-01-01

    The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6000 years before present (6 ka). For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records ba...

  12. Role of ozone in the solar cycle modulation of the North Atlantic Oscillation

    OpenAIRE

    Kuroda, Yuhji; Yamazaki, Koji; Shibata, Kiyotaka

    2008-01-01

    The effect of ozone on the 11-year solar cycle modulation of the winter-mean North Atlantic Oscillation (NAO) is examined through analyses of observed meteorological and ozone data from 1978 to 2000. It is found that a significant ozone anomaly associated with the winter NAO is created in winter in high solar (HS) years only and the anomaly persists from spring to summer, creating a large temperature anomaly in the lower stratosphere through radiative heating. Such a temperature anomaly in th...

  13. Large-scale impact of Saharan dust on the North Atlantic Ocean circulation

    OpenAIRE

    Serra, N; Martínez Avellaneda, N.; Stammer, D.

    2014-01-01

    The potential for a dynamical impact of Saharan mineral dust on the North Atlantic Ocean large-scale circulation is investigated. To this end, an ocean general circulation model forced by atmospheric fluxes is perturbed by an idealized, seasonally varying, net shortwave flux anomaly, as it results from remote sensing observations of aerosol optical thickness representing Saharan dust load in the atmosphere. The dust dynamical impact on the circulation is assessed through a comparison between ...

  14. The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region

    OpenAIRE

    Breiteig, Tarjei

    2009-01-01

    The North Atlantic Oscillation (NAO) is generally regarded to largely be a product of processes internal to the troposphere. This thesis investigates various aspects of how the NAO and related climatical fields are influenced by two of the tropospheric boundary components; the stratosphere above and the ocean below. The thesis consists of five manuscripts, three considering the role of the stratosphere, and two considering the role of the ocean. Data provided by the NCEP/NCA...

  15. Relationships between the North Atlantic Oscillation index and temperatures in Europe in global climate models

    Czech Academy of Sciences Publication Activity Database

    Beranová, Romana; Kyselý, Jan

    2013-01-01

    Roč. 57, č. 1 (2013), s. 138-153. ISSN 0039-3169 R&D Projects: GA ČR GAP209/10/2045 Institutional support: RVO:68378289 Keywords : North Atlantic Oscillation * global climate models * climate change * surface air temperature * Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.752, year: 2013 http://link.springer.com/article/10.1007%2Fs11200-012-0824-0#

  16. High-resolution Neogene and Quaternary estimates of Nubia-Eurasia-North America Plate motion

    Science.gov (United States)

    DeMets, C.; Iaffaldano, G.; Merkouriev, S.

    2015-10-01

    Reconstructions of the history of convergence between the Nubia and Eurasia plates constitute an important part of a broader framework for understanding deformation in the Mediterranean region and the closing of the Mediterranean Basin. Herein, we combine high-resolution reconstructions of Eurasia-North America and Nubia-North America Plate motions to determine rotations that describe Nubia-Eurasia Plate motion at ˜1 Myr intervals for the past 20 Myr. We apply trans-dimensional hierarchical Bayesian inference to the Eurasia-North America and Nubia-North America rotation sequences in order to reduce noise in the newly estimated Nubia-Eurasia rotations. The noise-reduced rotation sequences for the Eurasia-North America and Nubia-North America Plate pairs describe remarkably similar kinematic histories since 20 Ma, consisting of relatively steady seafloor spreading from 20 to 8 Ma, ˜20 per cent opening-rate slowdowns at 8-6.5 Ma, and steady plate motion from ˜7 Ma to the present. Our newly estimated Nubia-Eurasia rotations predict that convergence across the central Mediterranean Sea slowed by ˜50 per cent and rotated anticlockwise after ˜25 Ma until 13 Ma. Motion since 13 Ma has remained relatively steady. An absence of evidence for a significant change in motion immediately before or during the Messinian Salinity Crisis at 6.3-5.6 Ma argues against a change in plate motion as its causative factor. The detachment of the Arabian Peninsula from Africa at 30-24 Ma may have triggered the convergence rate slowdown before 13 Ma; however, published reconstructions of Nubia-Eurasia motion for times before 20 Ma are too widely spaced to determine with confidence whether the two are correlated. A significant discrepancy between our new estimates of Nubia-Eurasia motion during the past few Myr and geodetic estimates calls for further investigation.

  17. Interannual-to-decadal variability of the North Atlantic from an ocean data assimilation system

    Energy Technology Data Exchange (ETDEWEB)

    Masina, S.; Di Pietro, P.; Navarra, A. [Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy)

    2004-10-01

    An ocean analysis, assimilating both surface and subsurface hydrographic temperature data into a global ocean model, has been produced for the period 1958-2000, and used to study the time and space variations of North Atlantic upper ocean heat content (HC). Observational evidence is presented for interannual-to-decadal variability of upper ocean thermal fluctuations in the North Atlantic related to the North Atlantic Oscillation (NAO) variability over the last 40 years. The assimilation scheme used in the ocean analysis is a univariate, variational optimum interpolation of temperature. The first guess is produced by an eddy permitting global ocean general circulation forced by atmospheric reanalysis from the National Center for Environmental Prediction (NCEP). The validation of the ocean analysis has been done through the comparison with objectively analyzed observations and independent data sets. The method is able to compensate for the model systematic error to reproduce a realistic vertical thermal structure of the region and to improve consistently the model estimation of the time variability of the upper ocean temperature. Empirical orthogonal function (EOF) analysis shows that an important mode of variability of the wintertime upper ocean climate over the North Atlantic during the period of study is characterized by a tripole pattern both for SST and upper ocean HC. A similar mode is found for summer HC anomalies but not for summer SST. Over the whole period, HC variations in the subtropics show a general warming trend while the tropical and north eastern part of the basin have an opposite cooling tendency. Superimposed on this linear trend, the HC variability explained by the first EOF both in winter and summer conditions reveals quasi-decadal oscillations correlated with changes in the NAO index. On the other hand, there is no evidence of correlation in time between the NAO index and the upper ocean HC averaged over the whole North Atlantic which exhibits a

  18. Economic integration in North America: Formal, Informal and Spatial Aspects.

    OpenAIRE

    Proulx, P.P.

    1996-01-01

    An exemination of a series of indicators of economic integration in the western hemisphere (Canada-USA-Latin America) indicates that it is proceeding under the influence of formal trade agreements and informal forces including technological change, multinational firm rationalization and location strategies, etc.

  19. Variability in north tropical atlantic over the last 20 000 years and holocene gulf stream activity

    International Nuclear Information System (INIS)

    Modern oceanographical studies shown that most of the ocean heat content in the North Atlantic Western Boundary Current region is stored in the upper 400 meters. To study past heat content and Gulf Stream activity, we performed coupled analyses of oxygen isotopic and trace elemental composition on several foraminifera species to reconstruct upper water column temperature and salinity. Calcification depths of Globorotalia inflata, Globorotalia truncatulinoides and Pulleniatina obliquiloculata have been constrain by correlating modern hydrographic data to oxygen isotopic measurement of North Atlantic core-top samples. We found that the three deep-dwelling foraminifera species have a preferred habitat at the base of the seasonal thermocline (Cleroux et al, 2007). The same set of North Atlantic core-tops has been used to define relationships between trace elemental compositions and temperature. We established calibrations between Mg/Ca ratio or Sr/Ca ratio and temperature for the three deep-dwelling foraminifera (Cleroux et al, submitted). We apply this strategy on the core MD99-2203 located off Cape Hatteras where the Gulf Stream separate from the United States coast. High-resolution surface reconstructions over the Holocene show low amplitude periodic temperature and salinity changes that could be related to NAO type mechanisms. Large hydrological changes in sub-surface reflect variations of Labrador current and Mode Water influences. Using recent studies on Mode Water formation and Gulf Stream heat advection, we interpret our results in term of ocean heat content and Gulf Stream activity. (author)

  20. What drives seasonal change in oligotrophic area in the subtropical North Atlantic?

    Science.gov (United States)

    Dave, Apurva C.; Barton, Andrew D.; Lozier, M. Susan; McKinley, Galen A.

    2015-06-01

    The oligotrophic regions of the subtropical gyres cover a significant portion of the global ocean, and exhibit considerable but poorly understood intraseasonal, interannual, and longer-term variations in spatial extent. Here using historical observations of surface ocean nitrate, wind, and currents, we have investigated how horizontal and vertical supplies of nitrate control seasonal changes in the size and shape of oligotrophic regions of the subtropical North Atlantic. In general, the oligotrophic region of the subtropical North Atlantic is associated with the region of weak vertical supply of nitrate. Though the total vertical supply of nitrate here is generally greater than the total horizontal supply, we find that seasonal expansion and contraction of the oligotrophic region is consistent with changes in horizontal supply of nitrate. In this dynamic periphery of the subtropical gyre, the seasonal variations in chlorophyll are linked to variations in horizontal nitrate supply that facilitate changes in intracellular pigment concentrations, and to a lesser extent, phytoplankton biomass. Our results suggest that horizontal transports of nutrient are crucial in setting seasonal cycles of chlorophyll in large expanses of the subtropical North Atlantic, and may play a key and underappreciated role in regulating interannual variations in these globally important marine ecosystems.

  1. The mechanism of multidecadal variability in the Arctic and North Atlantic in climate model INMCM4

    International Nuclear Information System (INIS)

    Data from a 500-year preindustrial control run of climate model INMCM4 show distinct climate variability in the Arctic and North Atlantic with a period of 35–50 years. The variability can be seen as anomalies of upper ocean density that appear in the Arctic and propagate to the North Atlantic. The density gradient in a northeast–southwest direction alternates with the density gradient in a northwest–southeast direction. A positive density anomaly in the Arctic is associated with a positive salinity anomaly, a positive surface temperature anomaly and a reduction of sea ice in the Barents and Kara Seas. The nature of the variability is a vertical advection of density by thermal currents similar to that proposed in Dijkstra et al (2008 Phil. Trans. R. Soc. A 366). The cycle of model variability shows that after a negative anomaly of density in the northwest Atlantic, one should expect warming in the Arctic in 5–10 years. The ensemble of decadal predictions with climate model INMCM4 starting from 1995 shows that warming in the western Arctic and especially in the Barents Sea observed in 1996–2010 can be reproduced by eight of ten ensemble members. Arctic climate predictability in this case is associated with a proposed mechanism of a 35–50 year North Atlantic–Arctic oscillation. (letter)

  2. North atlantic deepwater temperature change during late pliocene and late quaternary climatic cycles

    Science.gov (United States)

    Dwyer, G.S.; Cronin, T. M.; Baker, P.A.; Raymo, M.E.; Buzas, Jeffrey S.; Correge, T.

    1995-01-01

    Variations in the ratio of magnesium to calcium (Mg/Ca) in fossil ostracodes from Deep Sea Drilling Project Site 607 in the deep North Atlantic show that the change in bottom water temperature during late Pliocene 41,000-year obliquity cycles averaged 1.5??C between 3.2 and 2.8 million years ago (Ma) and increased to 2.3??C between 2.8 and 2.3 Ma, coincidentally with the intensification of Northern Hemisphere glaciation. During the last two 100,000-year glacial-to-interglacial climatic cycles of the Quaternary, bottom water temperatures changed by 4.5??C. These results show that glacial deepwater cooling has intensified since 3.2 Ma, most likely as the result of progressively diminished deep-water production in the North Atlantic and of the greater influence of Antarctic bottom water in the North Atlantic during glacial periods. The ostracode Mg/Ca data also allow the direct determination of the temperature component of the benthic foraminiferal oxygen isotope record from Site 607, as well as derivation of a hypothetical sea-level curve for the late Pliocene and late Quaternary. The effects of dissolution on the Mg/Ca ratios of ostracode shells appear to have been minimal.

  3. Phylogeography of Labrus bergylta (Pisces: Labridae in the north-eastern Atlantic

    Directory of Open Access Journals (Sweden)

    Frederico Almada

    2015-12-01

    Full Text Available The ballan wrasse, Labrus bergylta (Labridae, is a protogynous hermaphrodite fish common in the north-eastern Atlantic from Norway to Morocco. It is a commercially important resource for local fisheries and is currently being used as cleaner fish to control sea lice in salmon farms in northern Europe. We analysed the phylogeographic patterns of this species using mitochondrial (control region and nuclear (I intron of the S7 gene markers in populations throughout its distributional range. The results revealed a marked genetic structure of L. bergylta along the sampled area, with a major separation found between the Archipelago of the Azores and all remaining locations and also a clear separation between the north-eastern Atlantic and Scandinavian locations. Similarly to other temperate species the genetic diversity decreased from north-eastern Atlantic to Scandinavian populations. Haplotype networks confirm the distinctiveness of the population from the Azores and show that Scandinavian populations also present some distinct haplotypes. The phylogeographic pattern and diversity indices found for the ballan wrasse are discussed and compared with others found for different labrid species. The recognition of different populations of L. bergylta may be an in important result for fisheries management and also for future regulation of capture and translocation of specimens to be used as cleaners in aquaculture facilities.

  4. Explosive development of winter storm Xynthia over the subtropical North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    M. L. R. Liberato

    2013-09-01

    Full Text Available In winter of 2009–2010 south-western Europe was hit by several destructive windstorms. The most important was Xynthia (26–28 February 2010, which caused 64 reported casualties and was classified as the 2nd most expensive natural hazard event for 2010 in terms of economic losses. In this work we assess the synoptic evolution, dynamical characteristics and the main impacts of storm Xynthia, whose genesis, development and path were very uncommon. Wind speed gusts observed at more than 500 stations across Europe are evaluated as well as the wind gust field obtained with a regional climate model simulation for the entire North Atlantic and European area. Storm Xynthia was first identified on 25 February around 30° N, 50° W over the subtropical North Atlantic Ocean. Its genesis occurred on a region characterized by warm and moist air under the influence of a strong upper level wave embedded in the westerlies. Xynthia followed an unusual SW–NE path towards Iberia, France and central Europe. The role of moist air masses on the explosive development of Xynthia is analysed by considering the evaporative sources. A lagrangian model is used to identify the moisture sources, sinks and moisture transport associated with the cyclone during its development phase. The main supply of moisture is located over an elongated region of the subtropical North Atlantic Ocean with anomalously high SST, confirming that the explosive development of storm Xynthia had a significant contribution from the subtropics.

  5. Temperature-dependence of planktonic metabolism in the Subtropical North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    L. S. García-Corral

    2014-02-01

    Full Text Available The temperature dependence of planktonic metabolism in the Subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP, community respiration (CR and net community production (NCP, as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperatures gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, being the highest rates observed during the spring transect. The overall mean integrated GPP/CR ratio was of 1.39 ± 0.27 decreasing from winter to summer and the NCP for the Subtropical North Atlantic Ocean during this cruises, was net autotrophy (NCP > 0 in about two-thirds of the total sampled communities (68.2%. Here, we reported the activation energies describing the temperature-dependence of planktonic community metabolism, which generally was higher for CR than for GPP in the Subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Also, we performed an assessment of the activation energies describing the responses to in situ temperature at field (EaCR = 1.64 ± 0.36 eV and those derive experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV, which showed a great consistency.

  6. Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C. Andersson

    2009-07-01

    Full Text Available The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6 ka. For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3 upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

  7. Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C. Andersson

    2010-03-01

    Full Text Available The early to mid-Holocene thermal optimum is a well-known feature in a wide variety of paleoclimate archives from the Northern Hemisphere. Reconstructed summer temperature anomalies from across northern Europe show a clear maximum around 6000 years before present (6 ka. For the marine realm, Holocene trends in sea-surface temperature reconstructions for the North Atlantic and Norwegian Sea do not exhibit a consistent pattern of early to mid-Holocene warmth. Sea-surface temperature records based on alkenones and diatoms generally show the existence of a warm early to mid-Holocene optimum. In contrast, several foraminifer and radiolarian based temperature records from the North Atlantic and Norwegian Sea show a cool mid-Holocene anomaly and a trend towards warmer temperatures in the late Holocene. In this paper, we revisit the foraminifer record from the Vøring Plateau in the Norwegian Sea. We also compare this record with published foraminifer based temperature reconstructions from the North Atlantic and with modelled (CCSM3 upper ocean temperatures. Model results indicate that while the seasonal summer warming of the sea-surface was stronger during the mid-Holocene, sub-surface depths experienced a cooling. This hydrographic setting can explain the discrepancies between the Holocene trends exhibited by phytoplankton and zooplankton based temperature proxy records.

  8. Climatic freshening of the deep North Atlantic (north of 500N) over the past 20 years. Final report

    International Nuclear Information System (INIS)

    The Transient Tracers in the Ocean (TTO) program was initiated as a multi-institution, multi-year effort to study ocean transport processes by measuring the distributions of man-made trace substances as they penetrate into the oceans. During the first major field effort of the TTO program, we carried out a seven leg cruise in 1981, occupying 250 geochemical stations covering the North Atlantic from 150N to Spitsbergen. Samples were taken for the measurement of tracers such as tritium (and its daughter 3He) and 14C which were produced by atmospheric nuclear weapons testing, and tracers that are byproducts of industrial activities, e.g. 85Kr and trichlorofluoromethane. In addition, a series of precise measurements of nutrients, dissolved oxygen and hydrographic properties were made. We report here preliminary hydrographic results from the three most northerly legs, which show a temperature-salinity relationship throughout a large portion of the water volume north of 500N systematically different from previously obtained (IGY) data. We contend that this difference is a result of a climatic variation in atmospheric and cryospheric conditions which manifest itself in a net change in the temperature and salinity characteristics of the overflow waters which supply the North Atlantic Deep Water masses. 11 references, 3 figures

  9. Gravity anomalies, plate tectonics and the lateral growth of Precambrian North America

    Science.gov (United States)

    Thomas, M. D.; Grieve, R. A. F.; Sharpton, V. L.

    1988-01-01

    The widespread gravity coverage of North America provides a picture of the gross structural fabric of the continent via the trends of gravity anomalies. The structural picture so obtained reveals a mosaic of gravity trend domains, many of which correlate closely with structural provinces and orogenic terranes. The gravity trend map, interpreted in the light of plate-tectonic theory, thus provides a new perspective for examining the mode of assembly and growth of North America. Suture zones, palaeosubduction directions, and perhaps, contrasting tectonic histories may be identified using gravity patterns.

  10. The southern edge of cratonic North America: Evidence from new magnetic satellite observations

    DEFF Research Database (Denmark)

    Purucker, M.; Mandea, M.; Hulot, G.;

    2002-01-01

    A global model is developed for both induced and remanent magnetizations in the terrestrial lithosphere. The model is compared with, and well-described by, Ørsted satellite observations. Interpretation of the observations over North America suggests that the large total field anomalies, associated...... with spherical harmonic degrees 15-26 and centered over Kentucky and the south-central United States, are the manifestations of the magnetic edges of the southern boundaries of cratonic North America. The techniques and models developed here may be of use in defining other cratonic boundaries....

  11. The southern edge of cratonic North America: Evidence from new satellite magnetometer observations

    DEFF Research Database (Denmark)

    Purucker, M.; Langlais, B.; Olsen, Nils;

    2002-01-01

    [1] A global model is developed for both induced and remanent magnetizations in the terrestrial lithosphere. The model is compared with, and well-described by, Orsted satellite observations. Interpretation of the observations over North America suggests that the large total field anomalies......, associated with spherical harmonic degrees 15-26 and centered over Kentucky and the south-central United States, are the manifestations of the magnetic edges of the southern boundaries of cratonic North America. The techniques and models developed here may be of use in defining other cratonic boundaries....

  12. Gravity anomalies, plate tectonics and the lateral growth of Precambrian North America

    International Nuclear Information System (INIS)

    The widespread gravity coverage of North America provides a picture of the gross structural fabric of the continent via the trends of gravity anomalies. The structural picture so obtained reveals a mosaic of gravity trend domains, many of which correlate closely with structural provinces and orogenic terranes. The gravity trend map, interpreted in the light of plate-tectonic theory, thus provides a new perspective for examining the mode of assembly and growth of North America. Suture zones, palaeosubduction directions, and perhaps, contrasting tectonic histories may be identified using gravity patterns

  13. The GBVP approach for vertical datum unification: recent results in North America

    Science.gov (United States)

    Amjadiparvar, B.; Rangelova, E.; Sideris, M. G.

    2016-01-01

    Two levelling-based vertical datums have been used in North America, namely CGVD28 in Canada and NAVD88 in the USA and Mexico. Although the two datums will be replaced by a common and continent-wide vertical datum in a few years, their connection and unification are of great interest to the scientific and user communities. In this paper, the geodetic boundary value problem (GBVP) approach is studied as a rigorous method for connecting two or more vertical datums through computed datum offsets from a global equipotential surface defined by a GOCE-based geoid. The so-called indirect bias term, the effect of the GOCE geoid omission error, the effect of the systematic levelling datum errors and distortions, and the effect of the geodetic data errors on the datum unification are four important factors affecting the practical implementation of this approach. These factors are investigated numerically using the GNSS-levelling and tide gauge stations in Canada, the USA, Alaska, and Mexico. The results show that the indirect bias term can be omitted if a GOCE-based global geopotential model is used in gravimetric geoid computations. The omission of the indirect bias term simplifies the linear system of equations for the estimation of the datum offset(s). Because of the existing systematic levelling errors and distortions in the Canadian and US levelling networks, the datum offsets are investigated in eight smaller regions along the Canadian and US coastal areas. Using GNSS-levelling stations in the US coastal regions, the mean datum offset can be estimated with a 1 cm standard deviation if the GOCE geoid omission error is taken into account by means of the local gravity and topographic information. In the Canadian Atlantic and Pacific regions, the datum offsets can be estimated with 2.3 and 3.5 cm standard deviation, respectively, using GNSS-levelling stations. However, due to the low number of tide gauge stations, the standard deviation of the CGVD28 and NAVD88 datum

  14. Wind Powering America: The Next Steps in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Banks, Jennifer L. [North Carolina Solar Center; Scanlin, Dennis [Appalachian State University; Quinlan, Paul [North Carolina Sustainable Energy Association

    2013-06-18

    The goal of this project is to apply the WPA’s proactive outreach strategy to the problem of educating the public about the likely transmission infrastructure developments concomitant to the significant development of wind energy resources in North Carolina. Given the lead time to develop significant new transmission infrastructure (5-10 years), it is critical to begin this outreach work today, so that wind resources can be developed to adequately meet the 20% by 2030 goal in the mid- to long-term (10-20 years). The project team planned to develop a transmission infrastructure outreach campaign for North Carolina by: (1) convening a utility interest group (UIG) of the North Carolina Wind Working Group (NC WWG) consisting of electric utilities in the state and the Southeast; and (2) expanding outreach to local and state government officials in North Carolina.

  15. North and South Atlantic Bidecadal SL variability: Rossby Waves, AMOC fingerprints and Regime Shifts

    Science.gov (United States)

    Vianna, M. L.; Menezes, V. V.

    2014-12-01

    The relationship between the North and South Atlantic bidecadal sea level (SL) oscillations in the twentieth century (1908-2008) is investigated using SODA 2.2.4 reanalysis and 102 monthly mean SL time series from TG stations provided by PSMSL. Bidecadal SL signal extraction was done using our method of subjectively choosing groupings of space-time data into non-overlapping period bands by use of Singular Spectrum Analysis (SSA)/ Maximum Entropy Method (MEM) analysis. A CEOF analysis of the SODA bidecadal band shows dominance of 22-24 year periods. Propagating bidecadal mode expansions were then determined through this analysis, which gives two principal modes. The first mode is dominant from 1915 to 1965 and the second from 1970 onward. The amplitude variabilities obtained suggests the presence of regime shifts, which coincide in time with shifts actually observed in European climate and South African lobster fisheries. The first mode is characterized by states with North and South Atlantic subtropical gyres in phase, while tropical and subpolar regions are in opposite phase relative to them. The second mode is characterized by the subpolar gyre and North subtropical gyre almost in quadrature, with North and South subtropical gyres out of phase. The evolution mechanism of this latter mode is related to east-west density contrasts and westward propagating Rossby waves. These waves show phase speeds dominated by geostrophic self-advection of density anomalies relative to the mean meridional density gradient as known from previous studies, but are shown to be additionally influenced by bottom topography. The oscillations caused by these waves are shown to have phase differences (quadrature in the North Atlantic) with regional indices of bidecadal AMOC oscillations. A number of SL-AMOC fingerprints are also reviewed, and a new eastern equatorial fingerprint is proposed.

  16. Diversity and distribution of microbial eukaryotes in the deep tropical and subtropical North Atlantic Ocean

    Science.gov (United States)

    Morgan-Smith, Danielle; Clouse, Melissa A.; Herndl, Gerhard J.; Bochdansky, Alexander B.

    2013-08-01

    Employing a combination of 4',6-diamidino-2-phenylindole and fluorescein isothiocyanate (DAPI-FITC) staining and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), we distinguished a variety of taxonomic and morphological types of eukaryotic microbes in the central and deep water masses of the tropical and subtropical North Atlantic Ocean. Samples were taken along a transect across the tropical Atlantic, along the equatorial upwelling and into the West-African upwelling region. Samples were collected as deep as 7000 m in the Romanche Fracture Zone within the Mid-Atlantic Ridge. Approximately 50-70% of FISH-identified eukaryotes in deep water masses belong to one of seven groups: kinetoplastids, labyrinthulomycetes, fungi, diplonemids, group II alveolates, MAST 4 (stramenopiles), and an unidentified organism with a peculiar nuclear morphology. A smaller percentage of total eukaryotes was identified in the Central Water, especially in the oxygen minimum zone, than in deep water masses. CARD-FISH probes designed to identify broad taxonomic groups revealed kinetoplastids and fungi were more abundant than noted in previous studies employing 18S rRNA gene clone libraries. Group II alveolates, in contrast, were much less prevalent than previously reported. On a second survey, eukaryotic microbes were enumerated in the deep-sea basins below the North Atlantic subtropical gyre including the Vema Fracture Zone, which is another prominent trench in the Mid-Atlantic Ridge. The abundance of eukaryotes and chlorophyll concentrations were significantly different between the two cruises, which covered very different hydrographic regimes with associated high and low levels of primary production, respectively.

  17. Biogeography of jellyfish in the North Atlantic, by traditional and genomic methods

    Science.gov (United States)

    Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R. R.; Raab, K.; Stern, R.; Tranter, P.

    2015-07-01

    Scientific debate on whether or not the recent increase in reports of jellyfish outbreaks represents a true rise in their abundance has outlined a lack of reliable records of Cnidaria and Ctenophora. Here we describe different jellyfish data sets produced within the EU programme EURO-BASIN. These data were assembled with the aim of creating an improved baseline and providing new data that can be used to evaluate the current diversity and standing stocks of jellyfish in the North Atlantic region. Using a net adapted to sample gelatinous zooplankton quantitatively, cnidarians and ctenophores were collected from the epipelagic layer during spring-summer 2010-2013, in inshore and offshore waters between lat 59 and 68° N and long 62° W and 5° E. Jellyfish were also identified and counted in samples opportunistically collected by other sampling equipment in the same region and at two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of cnidarian blooms across the North Atlantic Basin. Overall the data show high variability in jellyfish abundance and diversity, mainly in relation to different water masses and bathymetry. Higher densities were generally recorded on the shelves, where the communities tend to be more diverse due to the presence of meropelagic medusae. Comparison of net records from the G.O. Sars transatlantic cruise shows that information on jellyfish diversity differs significantly depending on the sampling gear utilised. Indeed, the big trawls mostly collect relatively large scyphozoan and hydrozoan species, while small hydrozoans and early stages of Ctenophora are only caught by smaller nets. Based on CPR data from 2009 to 2012, blooms of cnidarians occurred in all seasons across the whole North Atlantic Basin. Molecular analysis revealed that, contrary to previous hypotheses, the CPR is able to detect

  18. The role of emergency medicine physicians in trauma care in North America: evolution of a specialty

    OpenAIRE

    Grossman Michael D

    2009-01-01

    Abstract The role of Emergency Medicine Physicians (EMP) in the care of trauma patients in North America has evolved since the advent of the specialty in the late 1980's. The evolution of this role in the context of the overall demands of the specialty and accreditation requirements of North American trauma centers will be discussed. Limited available data published in the literature examining the role of EMP's in trauma care will be reviewed with respect to its implications for an expanded r...

  19. An animated tectonic reconstruction of southwestern North America since 36 Ma

    OpenAIRE

    McQuarrie, Nadine; Wernicke, Brian P.

    2005-01-01

    We present tectonic reconstructions and an accompanying animation of deformation across the North America–Pacific plate boundary since 36 Ma. Intraplate deformation of southwestern North America was obtained through synthesis of kinematic data (amount, timing, and direction of displacement) along three main transects through the northern (40°N), central (36°N– 37°N), and southern (34°N) portions of the Basin and Range province. We combined these transects with...

  20. Common Ancestry of Borrelia burgdorferi Sensu Lato Strains from North America and Europe

    OpenAIRE

    Postic, D; Ras, N. Marti; Lane, R S; Humair, P.-F.; Wittenbrink, M. M.; Baranton, G

    1999-01-01

    Ten atypical European Borrelia burgdorferi sensu lato (Borrelia spp.) strains were genetically characterized, and the diversity was compared to that encountered among related Borrelia spp. from North America. Phylogenetic analyses of a limited region of the genome and of the whole genome extend existing knowledge about borrelial diversity reported earlier in Europe and the United States. Our results accord with the evidence that North American and European strains may have a common ancestry.

  1. A Market Analysis for PVD Coating System of Aurora North America

    OpenAIRE

    Chen, Wen-Hao Arthur

    2012-01-01

    Aurora North America, a venture founded by Dr. Da-Yung Wang, endeavours to offer its coating products while providing low-cost, quality solutions to North American manufacturers who apply thin-films to their goods. The objective of this proposed research is to provide a comprehensive analysis of the market opportunities for Aurora. This paper seeks to identify markets that have yet to fully adopt Physical Vapor Deposition (PVD) technology, as well as their potential customers. Market trend of...

  2. Initial Value Predictability of Intrinsic Oceanic Modes and Implications for Decadal Prediction over North America

    Energy Technology Data Exchange (ETDEWEB)

    Branstator, Grant

    2014-12-09

    The overall aim of our project was to quantify and characterize predictability of the climate as it pertains to decadal time scale predictions. By predictability we mean the degree to which a climate forecast can be distinguished from the climate that exists at initial forecast time, taking into consideration the growth of uncertainty that occurs as a result of the climate system being chaotic. In our project we were especially interested in predictability that arises from initializing forecasts from some specific state though we also contrast this predictability with predictability arising from forecasting the reaction of the system to external forcing – for example changes in greenhouse gas concentration. Also, we put special emphasis on the predictability of prominent intrinsic patterns of the system because they often dominate system behavior. Highlights from this work include: • Development of novel methods for estimating the predictability of climate forecast models. • Quantification of the initial value predictability limits of ocean heat content and the overturning circulation in the Atlantic as they are represented in various state of the artclimate models. These limits varied substantially from model to model but on average were about a decade with North Atlantic heat content tending to be more predictable than North Pacific heat content. • Comparison of predictability resulting from knowledge of the current state of the climate system with predictability resulting from estimates of how the climate system will react to changes in greenhouse gas concentrations. It turned out that knowledge of the initial state produces a larger impact on forecasts for the first 5 to 10 years of projections. • Estimation of tbe predictability of dominant patterns of ocean variability including well-known patterns of variability in the North Pacific and North Atlantic. For the most part these patterns were predictable for 5 to 10 years. • Determination of

  3. Variability and propagation of Labrador Sea Water in the southern subpolar North Atlantic

    Science.gov (United States)

    Kieke, Dagmar; Klein, Birgit; Stramma, Lothar; Rhein, Monika; Koltermann, Klaus Peter

    2009-10-01

    The variability of two modes of Labrador Sea Water (LSW) (upper and deep Labrador Sea Water) and their respective spreading in the interior North Atlantic Ocean are investigated by means of repeated ship surveys carried out along the zonal WOCE line A2/AR19 located at 43-48°N (1993-2007) and along the GOOS line at about 48-51°N (1997-2002). Hydrographic section data are complemented by temperature, salinity, and velocity time series recorded by two moorings. They have been deployed at the western flank of the Mid-Atlantic Ridge (MAR) in the Newfoundland Basin during 1996-2004. The analysis of hydrographic anomalies at various longitudes points to a gradual eastward propagation of LSW-related signals, which happens on time scales of 3-6 years from the formation region towards the MAR. Interactions of the North Atlantic Current (NAC) with the Deep Western Boundary Current (DWBC) close to Flemish Cap point to the NAC being the main distributor of the different types of LSW into the interior of the Newfoundland Basin. Comparisons between the ship data and the mooring records revealed that the mooring sites are located in a region affected by highly variable flow. The mooring time series demonstrate an elevated level of variability with eddy activity and variability associated with the NAC considerably influencing the LSW signals in this region. Hydrographic data taken from Argo profiles from the vicinity of the mooring sites turned out to mimic quite well the temporal evolution captured by the moorings. There is some indication of occasional southward flow in the LSW layer near the MAR. If this can be considered as a hint to an interior LSW-route, it is at least of minor importance in comparison to the DWBC. It acts as an important supplier for the interior North Atlantic, distributing older and recently formed LSW modes southward along the MAR.

  4. Modal composition of the central water in the North Atlantic subtropical gyre

    Directory of Open Access Journals (Sweden)

    A. Cianca

    2009-10-01

    Full Text Available The modal composition of the Central Water in the North Atlantic subtropical gyre is not clearly defined, as there are some uncertainties related to mode identification, as well as modes which are not well documented. This study shows that eastern North Atlantic Central Water (eastern NACW in the subtropical gyre is composed of three modes: The North Atlantic Subpolar Mode Water (NASPMW σt=27.1 to 27.3, the Madeira Mode Water (MMW σt=26.4 to 26.6, and the mode water with a σt near 27.0, which is currently not well documented. We confirmed this mode based on the similarities found between it and the mode waters already reported. The similarities were determined from comparative analyses of the temperature/salinity standard curves and the gradients of the potential density anomalies of two concurrent data sets from two subtropical time-series stations (Bermuda Atlantic Time-series Study, BATS, in the west, and European Station for Time-series in the Ocean Canary Islands, ESTOC, in the east. In order to establish the outcropping regions, the corresponding pycnostads were determined using another climatologic data set (World Ocean Database, WOD2005. In this case, the pycnostads were located based on the presence of standard deviation minima from the average density anomalies. Finally, we confirmed that the pycnostads corresponded to the temperature values related to the modes by overlaying the characteristic modal isotherm of each of the modes in the geographic distribution of the pycnostads. Sea surface temperature data (SST from the Ocean Pathfinder Program (OPP were used to estimate the isotherms. The results showed a clear correspondence between the modal isotherms and the pycnostads, for both the modes that have already been documented and the mode confirmed in this study.

  5. Seasonal phytoplankton blooms in the North Atlantic linked to the overwintering strategies of copepods

    Directory of Open Access Journals (Sweden)

    Kevin D. Friedland

    2016-04-01

    Full Text Available Abstract The North Atlantic Ocean contains diverse patterns of seasonal phytoplankton blooms with distinct internal dynamics. We analyzed blooms using remotely-sensed chlorophyll a concentration data and change point statistics. The first bloom of the year began during spring at low latitudes and later in summer at higher latitudes. In regions where spring blooms occurred at high frequency (i.e., proportion of years that a bloom was detected, there was a negative correlation between bloom timing and duration, indicating that early blooms last longer. In much of the Northeast Atlantic, bloom development extended over multiple seasons resulting in peak chlorophyll concentrations in summer. Spring bloom start day was found to be positively correlated with a spring phenology index and showed both positive and negative correlations to sea surface temperature and the North Atlantic Oscillation in different regions. Based on the characteristics of spring and summer blooms, the North Atlantic can be classified into two regions: a seasonal bloom region, with a well-defined bloom limited to a single season; and a multi-seasonal bloom region, with blooms extending over multiple seasons. These regions differed in the correlation between bloom start and duration with only the seasonal bloom region showing a significant, negative correlation. We tested the hypothesis that the near-surface springtime distribution of copepods that undergo diapause (Calanus finmarchicus, C. helgolandicus, C. glacialis, and C. hyperboreus may contribute to the contrast in bloom development between the two regions. Peak near-surface spring abundance of the late stages of these Calanoid copepods was generally associated with areas having a well-defined seasonal bloom, implying a link between bloom shape and their abundance. We suggest that either grazing is a factor in shaping the seasonal bloom or bloom shape determines whether a habitat is conducive to diapause, while recognizing

  6. 75 FR 51846 - BlueScope Buildings North America Including Workers Whose Unemployment Insurance (UI) Wages Are...

    Science.gov (United States)

    2010-08-23

    ... Register on June 7, 2010 (75 FR 32224). At the request of the State Agency, the Department reviewed the... Employment and Training Administration BlueScope Buildings North America Including Workers Whose Unemployment...Scope Buildings North America had their wages reported through a separate unemployment insurance...

  7. 76 FR 44623 - Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South...

    Science.gov (United States)

    2011-07-26

    ... COMMISSION Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South... portion of this proceeding regarding the application of Nuclear Innovation North America LLC (NINA) for... and Economic Development Coalition, the South Texas Association for Responsible Energy, and...

  8. 78 FR 68102 - Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South...

    Science.gov (United States)

    2013-11-13

    ... COMMISSION Atomic Safety and Licensing Board; In the Matter of Nuclear Innovation North America LLC (South... application of Nuclear Innovation North America LLC (NINA) for combined licenses that would authorize NINA to.../reactors/new-reactors/col/south-texas-project.html . These and other documents relating to this...

  9. 77 FR 39689 - Application To Export Electric Energy; IPR-GDF SUEZ Energy Marketing North America, Inc.

    Science.gov (United States)

    2012-07-05

    ..., Federal power marketing agencies, and other entities within the United States. The existing international... Application To Export Electric Energy; IPR-GDF SUEZ Energy Marketing North America, Inc. AGENCY: Office of... Marketing North America, Inc. (GSEMNA) has applied for authority to transmit electric energy from the...

  10. 75 FR 64306 - Shell Energy North America (US), LP; Notice of Institution of Proceeding and Refund Effective Date

    Science.gov (United States)

    2010-10-19

    ... Energy Regulatory Commission Shell Energy North America (US), LP; Notice of Institution of Proceeding and... U.S.C. 824e (2005), concerning the justness and reasonableness of Shell Energy North America (US), LP's market- based rate authority in the Central and Southwest balancing authority area. Shell...

  11. 75 FR 76037 - HAVI Logistics, North America a Subsidiary of HAVI Group, LP Including On-Site Leased Workers of...

    Science.gov (United States)

    2010-12-07

    ..., Bloomingdale, Illinois. The Notice was published in the Federal Register on September 21, 2010 (75 FR 57516... Employment and Training Administration HAVI Logistics, North America a Subsidiary of HAVI Group, LP Including... Logistics, North America, Lisle, IL; Amended Certification Regarding Eligibility To Apply for...

  12. 76 FR 16447 - Lafarge North America, Inc., a Subsidiary of Lafarge, Including On-Site Leased Workers From...

    Science.gov (United States)

    2011-03-23

    ... December 13, 2010 (75 FR 77668). At the request of the State agency, the Department reviewed the... Employment and Training Administration Lafarge North America, Inc., a Subsidiary of Lafarge, Including On..., applicable to workers of Lafarge North America, Inc., a subsidiary of Lafarge, Seattle, Washington....

  13. 77 FR 52393 - Petition for Exemption From the Vehicle Theft Prevention Standard; BMW of North America, LLC

    Science.gov (United States)

    2012-08-29

    ... Standard; BMW of North America, LLC AGENCY: National Highway Traffic Safety Administration (NHTSA... full the BMW of North America, LLC (BMW) petition for exemption of the Carline 4 vehicle line in... parts-marking requirements of the Theft Prevention Standard (49 CFR part 541). BMW...

  14. 77 FR 37956 - BMW of North America, LLC, a Subsidiary of BMW AG; Receipt of Petition for Decision of...

    Science.gov (United States)

    2012-06-25

    ... Register published on April 11, 2000, (65 FR 19477-78). The petition, supporting materials, and all... National Highway Traffic Safety Administration BMW of North America, LLC, a Subsidiary of BMW AG; Receipt... Administration, DOT. ACTION: Receipt of Petition. SUMMARY: BMW of North America, LLC,\\1\\ a subsidiary of BMW...

  15. 77 FR 63415 - BMW of North America, LLC, a Subsidiary of BMW AG, Receipt of Petition for Decision of...

    Science.gov (United States)

    2012-10-16

    ... Statement is available for review in the Federal Register published on April 11, 2000, (65 FR 19477-78). The... National Highway Traffic Safety Administration BMW of North America, LLC, a Subsidiary of BMW AG, Receipt... Administration, DOT. ACTION: Receipt of petition. SUMMARY: BMW North America, LLC,\\1\\ a subsidiary of BMW...

  16. 77 FR 56700 - BMW of North America, LLC, a Subsidiary of BMW AG, Receipt of Petition for Decision of...

    Science.gov (United States)

    2012-09-13

    ... Statement is available for review in the Federal Register published on April 11, 2000, (65 FR 19477-78). The... National Highway Traffic Safety Administration BMW of North America, LLC, a Subsidiary of BMW AG, Receipt... Administration, DOT. ACTION: Receipt of petition. SUMMARY: BMW of North America, LLC (BMW),\\1\\ a subsidiary...

  17. 78 FR 21189 - Petition for Exemption From the Vehicle Theft Prevention Standard; BMW of North America, LLC

    Science.gov (United States)

    2013-04-09

    ... the agency (58 FR 44872, dated August 25, 1993), NHTSA's review of the theft data for 10 General... Standard; BMW of North America, LLC AGENCY: National Highway Traffic Safety Administration (NHTSA... full the BMW of North America, LLC (BMW) petition for exemption of the X4 vehicle line in...

  18. 78 FR 43964 - BMW of North America, LLC, a Subsidiary of BMW AG, Grant of Petition for Decision of...

    Science.gov (United States)

    2013-07-22

    ... Register (77 FR 37956.) No comments were received. To view the petition and all supporting documents log... National Highway Traffic Safety Administration BMW of North America, LLC, a Subsidiary of BMW AG, Grant of... Administration, DOT. ACTION: Grant of petition. SUMMARY: BMW of North America, LLC \\1\\ a subsidiary of BMW...

  19. 78 FR 38799 - BMW of North America, LLC, a Subsidiary of BMW AG, Grant of Petition for Decision of...

    Science.gov (United States)

    2013-06-27

    ... a 30-day public comment period, on September 13, 2012 in the Federal Register (77 FR 56700). No... National Highway Traffic Safety Administration BMW of North America, LLC, a Subsidiary of BMW AG, Grant of... Administration, DOT. ACTION: Grant of Petition. SUMMARY: BMW of North America, LLC (BMW) \\1\\, a subsidiary of...

  20. 77 FR 45596 - Shell Energy North America (US), L.P. v. California Independent System Operator Corporation...

    Science.gov (United States)

    2012-08-01

    ... Energy Regulatory Commission Shell Energy North America (US), L.P. v. California Independent System... Energy North America (US), L.P. (Complainant) filed a formal complaint against the California Independent... Commission's list of Corporate Officials. Any person desiring to intervene or to protest this filing...