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.
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.
Ince, E. S.; Sideris, M. G.; Rangelova, E.
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.
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.
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
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
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...
Sallenger,, Asbury H., Jr.; Doran, Kara S.; Howd, Peter A.
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.
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.
Karegar, Makan A.; Dixon, Timothy H.; Engelhart, Simon E.
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.
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.
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.
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
Garver, Kyle A; Johnson, Stewart C; Polinski, Mark P; Bradshaw, Julia C; Marty, Gary D; Snyman, Heindrich N; Morrison, Diane B; Richard, Jon
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
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.
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.”
Lang, David C.; Bailey, Ian; Wilson, Paul A.; Foster, Gavin L.; Bolton, Clara T.; Friedrich, Oliver; Gutjahr, Marcus
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.
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...
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
Haug, G. H.; Deplazes, G.; Peterson, L. C.; Brauer, A.; Mingram, J.; Dulski, P.; Sigman, D. M.
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
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...
Christine, Dupuy; Hien, Nguyen Thanh; David, Mizrahi; Jérôme, Jourde; Martine, Bréret; Hélène, Agogué; Laureen, Beaugeard; Pierrick, Bocher
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
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
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.
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.
... DEFINITIONS § 120.31 North Atlantic Treaty Organization. North Atlantic Treaty Organization (NATO) is..., France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, The Netherlands,...
Blair, John E.A.; Huffman, Mark; Shah, Sanjiv J.
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...
Blair, John E A; Huffman, Mark; Shah, Sanjiv J
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
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...
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
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...
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,...
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...
Messori, Gabriele; Caballero, Rodrigo; Gaetani, Marco
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.
Hoogakker, B. A. A.; Thornalley, D. J. R.; Barker, S.
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
Ham, Yoo-Geun; Kug, Jong-Seong; Park, Jong-Yeon
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.
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...
... 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...
... 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...
Hunt, B. G.
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
Wenhong Li; Laifang Li; Yi Deng
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...
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...
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
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.
Karen T. Wei
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.
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
Sibuet, Jean-Claude; Rouzo, Stephane; Srivastava, Shiri
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...
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)
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
Sideris, Michael; Amjadiparvar, Babak
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
Tim D Smith
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.
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.)
... 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...
Keeley, Sarah; Sutton, Rowan; Shaffrey, Len
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...
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
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 ...
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
Zorita, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik; Saenz, J.; Fernandez, J.; Zubillaga, J. [Bilbao Univ. (Spain)
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.)
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
Brown, Jeremy [North American Comission for Environmental Cooperation (CEC), (United States)
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.
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
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.
Miller, D. A.; Waltman, S. W.; Geng, X.; James, D.; Hernandez, L.
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.
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.
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
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...
GADD, A. J.; HALL, C. D.; KRUZE, R. E.
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....
Alvarez-Garcia, F.; Latif, Mojib; Biastoch, Arne
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....
Lebedev, Sergei; Schaeffer, Andrew; Celli, Nicolas Luca
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.
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
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.
Rachel M Lee
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.
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.)
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.
Li, Hongmei; Ilyina, Tatiana; Müller, Wolfgang A.; Sienz, Frank
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.
Li, Hongmei; Ilyina, Tatiana; Müller, Wolfgang A; Sienz, Frank
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
Singh, H. B.; Brune, W H; J. H. Crawford; Jacob, Daniel J.; Russel, P. B.
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...
Ladd, Matthew; Viau, Andre; Gajewski, Konrad
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.
Howe, Jacob N. W.; Piotrowski, Alexander M.; Noble, Taryn L.; Mulitza, Stefan; Chiessi, Cristiano M.; Bayon, Germain
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.
... 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...
Lang, David C.; Bailey, Ian; Wilson, Paul A.; Chalk, Thomas B.; Foster, Gavin L.; Gutjahr, Marcus
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.
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.
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
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
Wild, Simon; Befort, Daniel J.; Leckebusch, Gregor C.
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.
Karma Lekshe Tsomo
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.
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
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.
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.
Moffa Sanchez, P.; Hall, I. R.; Born, A.; Thornalley, D. J.; Barker, S.; Richter, T.
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.
Friedlaender, Ari S.; Johnston, David W.; Halpin, Patrick N.
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.
Wei, Lisa H.; Homeier, Nichole; Gannon, Jennifer L.
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.
Wickert, A. D.; Anderson, R. S.; Mitrovica, J. X.; Picard, K.
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
Li, Jing-Jing; Hu, Zi-Min; Liu, Ruo-Yu; Zhang, Jie; Liu, Shao-Lun; Duan, De-Lin
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
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)
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.)
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...
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...
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...
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...
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...
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
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...
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...
Wu, Renguang; Yang, Song; Liu, Shi; Sun, Li; Lian, Yi; Gao, Zongting
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.
Chadwick, Heather Riley
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.
Galloway, James N.; Keene, William C.; Pszenny, Alexander A. P.; Whelpdale, Douglas M.; Sievering, Herman; Merrill, John T.; Boatman, Joe F.
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.
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.
Lucio-Eceiza, Etor E.; Fidel González-Rouco, J.; Navarro, Jorge; Hidalgo, Ángela; Conte, Jorge; Beltrami, Hugo
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
Tisdell, Elizabeth J.; Wright, Robin Redmon; Taylor, Edward W.
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,…
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.
Li, Wenhong; Li, Laifang; Deng, Yi
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.
Peña, Juan Carlos; Schulte, Lothar; Badoux, Alexandre
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
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
HUA Lijuan; MA Zhuguo; ZHONG Linhao
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.
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.
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.
Buchan, Jian; Hirschi, Joel; Blaker, Adam; Sinha, Bablu
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 ...
Liberato, Margarida L. R.
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
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.)
Sawatzky, H L; Lehn, W H
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
Lindemann, Christian; St. John, Michael
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...
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...
Hall, Timothy M.; Jewson, Stephen
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...
Graf, H; Walter, K.
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...
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
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...
Anell, Ingrid Anna Margareta; Thybo, Hans; Artemieva, Irina
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...
Peña-Izquierdo, Jesús; van Sebille, Erik; Pelegrí, Josep L.; Sprintall, Janet; Mason, Evan; Llanillo, Pedro J.; Machín, Francisco
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.
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)...
Piecuch, Christopher G.; Ponte, Rui M.
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.
Karma Lekshe Tsomo
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...
Zhao, Ping; Wang, Bin; Liu, Jiping; Zhou, Xiuji; Chen, Junming; Nan, Sulan; Liu, Ge; Xiao, Dong
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.
Zhao, Ping; Wang, Bin; Liu, Jiping; Zhou, Xiuji; Chen, Junming; Nan, Sulan; Liu, Ge; Xiao, Dong
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
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 ...
García Herrera, Ricardo; Gallego Puyol, David; Hernández Martín, Emiliano; Gimeno, Luis; Ribera Rodríguez, Pedro
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 ...
Stahle, D. W.; Therrell, M. D.; Cleaveland, M. K.; Fye, F. K.; Cook, E. R.; Grissino-Mayer, H. D.; Acuna-Soto, R.
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
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...
@@ 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.
F. Visser; K.L. Hartman; G.J. Pierce; V.D. Valavanis; J. Huisman
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,
Horton, B.; Vacchi, M.; Engelhart, S. E.; Nikitina, D.
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.
Narasimhan, T. N.
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
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.
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.
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.
Scholz, Tomáš; Choudhury, A.
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
Jones, Patrick M.
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…
Finn, C.A.; Pilkington, M.; Cuevas, A.; Hernandez, I.; Urrutia, J.
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.
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.
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)
MICHAEL H. STEPHENSON
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...
Leicht-Young, Stacey A.; Pavlovic, Noel B.
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.
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...
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...
Stendardo, I.; Gruber, N.
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.
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.
Engelhart, S. E.; Peltier, W. R.; Horton, B. P.; Khan, N. S.; Liu, S.; Vacchi, M.
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.
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
Reid, James B.; Pollock, Claire M.; Mavor, Roddy
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.
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.
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.
Klöcking, M.; White, N. J.; Maclennan, J.
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
Niskanen, Tuula; Liimatainen, Kare; Ammirati, Joseph F; Hughes, Karen
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
Matei, Daniela Mihaela; Pohlmann, Holger; Jungclaus, Johann; Müller, Wolfgang; Haak, Helmuth; Marotzke, Jochem
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
Mellinger, David K.; Clark, Christopher W.
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.
... 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...
... 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)...
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)
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
Björk, Mikael; Blanc, Dominique
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...
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
Dominguez, S.R.; O'Shea, T.J.; Oko, L.M.; Holmes, K.V.
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.
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.
Zhang, Yan; Yu, Hongbin; Eck, Tom F.; Smirnov, Alexander; Chin, Mian; Remer, Lorraine A.; Bian, Huisheng; Tan, Qian; Levy, Roberrt; Holben, Brent N.
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.
Atkins C J; Peel J S
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...
C Michael Honey; Anujan Poologaindran; Maureen Mayhew; Laura Vander Steen; Christopher Charles Gillis
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 ...
Eid, Mahmoud; Buchanan, Carrie
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 ...
Kinsella, J.M.; Cole, Rebecca A.; Forrester, Donald J.; Roderick, Constance L.
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.
Saeed Ahmed; Patompong Ungprasert; Supawat Ratanapo; Tanveer Hussain; Riesenfeld, Erik P.
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...
Bourquin, Charlotte; Holleran, James
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 ...
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
Dennis Slate; Timothy P Algeo; Kathleen M Nelson; Chipman, Richard B.; Dennis Donovan; Blanton, Jesse D.; Michael Niezgoda; Rupprecht, Charles E.
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...
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
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.
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
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.
Demets, Charles; Gordon, Richard G.; Stein, Seth; Argus, Donald F.
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.
... 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...
Tolwinski-Ward, S. E.; Stransky, S. M.
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.
Fuentes-Yaco, C.; Caverhill, C.; Maass, H.; Porter, C.; White, GN, III
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.
Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft;
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...
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)
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.
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.
Tsoukali, Stavroula; Visser, Andre; MacKenzie, Brian
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...
Altieri, Katye E; Fawcett, Sarah E; Peters, Andrew J; Sigman, Daniel M; Hastings, Meredith G
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
Conte, M. H.; Weber, J. C.; King, L. L.; Wakeham, S. G.
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
Sigloch, K.; Mihalynuk, M. G.
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
Wu, Zhiwei; Lin, Hai; Li, Jianping; Jiang, Zhihong; Ma, Tingting
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.
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.)
Han, Zhe; Luo, Feifei; Wan, Jianghua
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.
Morgana M. Macedo
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.
... 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...
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
Breivik, Øyvind; Bidlot, Jean-Raymond; Carrasco, Ana; Saetra, Øyvind; 10.1175/JCLI-D-12-00738.1
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...
Asmerom, Y.; Polyak, V. J.; Rasmussen, J.; Burns, S. J.; Lachniet, M. S.
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
...; 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...
Kurath, G.; Garver, K.A.; Troyer, R.M.;
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...
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...
Hayward, Jeremy; Tourtellot, Samuel G; Horton, Thomas R
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
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.
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
Brzezinski, Mark A.; Jones, Janice L.
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
Blehert, David S.; Lorch, Jeffrey M.; Ballmann, Anne E.; Cryan, Paul M.; Meteyer, Carol U.
* 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.
Methner, Katharina; Mulch, Andreas; Fiebig, Jens; Wacker, Ulrike; Gerdes, Axel; Graham, Stephan A.; Chamberlain, C. Page
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.
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 ...
Schuster, M.; Ulbrich, U.
. 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.
Gottschalk, Julia; Skinner, Luke C.; Misra, Sambuddha; Waelbroeck, Claire; Menviel, Laurie; Timmermann, Axel
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.
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...
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...
Carlson, Thomas J.; Halvorsen, Michele B.; Matzner, Shari; Copping, Andrea E.; Stavole, Jessica
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.
Goddard, Paul B; Yin, Jianjun; Griffies, Stephen M; Zhang, Shaoqing
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
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.
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.
Messacar, Kevin; Abzug, Mark J; Dominguez, Samuel R
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
Kathryn M. Magruder
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.
Scannell, Hillary A.; Pershing, Andrew J.; Alexander, Michael A.; Thomas, Andrew C.; Mills, Katherine E.
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.
Chen, Wei; Lee, June-Yi; Lu, Riyu; Dong, Buwen; Ha, Kyung-Ja
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...
Tamim Bayoumi; Trung Bui
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...
Schumann, U.; H. Schlager; F. Arnold; J. Ovarlez; Kelder, H.; O. Hov; Hayman, G.; I. S. A. Isaksen; Staehelin, J.; Whitefield, P.D.
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...
Chust, Guillem; Castellani, Claudia; Licandro, Priscilla; Ibaibarriaga, Leire; Sagarminaga, Yolanda; Irigoien, Xabier
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...
Guez, Oded; Berezin, Yehiel; Wang, Yang; Havlin, Shlomo
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.
Kauker, Frank; Gerdes, Rüdiger; Karcher, Michael; Köberle, Cornelia
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 ...
Jahnke-Bornemann, Annika; Brümmer, Burghard
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 ...
Ferreira, Ana Sofia; Payne, Mark; Mackenzie, Brian; Visser, Andre
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...
Schneider, E.K.; Kirtman, B. P.; Wu, Z.
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...
Gastineau, Guillaume; Frankignoul, Claude
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...
Andy Baker; Hellstrom, John C.; Kelly, Bryce F. J.; Gregoire Mariethoz; Valerie Trouet
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 (...
Grosfeld, K.; G. Lohmann; N. Rimbu; Fraedrich, K.; F. Lunkeit
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...
Lin, Hai; DEROME, JACQUES
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...
Susan E Parks; Warren, Joseph D.; Stamieszkin, Karen; Mayo, Charles A.; Wiley, David
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...
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.
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
Kurath, Gael; Winton, James R.; Dale, Ole Bendik; Purcell, Maureen K.; Falk, Knut; Busch, Robert D.
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.
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.
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
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.
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.
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.
S. K. Kravtsov
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.
Wilson, Robert M.
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.
Jouzeau, A.; Terray, L.
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.
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.; ,
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, ...
Yu, Jinhua; Li, Tim; Tan, Zhemin; Zhu, Zhiwei
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
Wanamaker, Alan D; Butler, Paul G; Scourse, James D; Heinemeier, Jan; Eiríksson, Jón; Knudsen, Karen Luise; Richardson, Christopher A
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
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.
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...
Worcester, R.; Ydenberg, R.C.
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
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Thompson, P. R.; Mitchum, G. T.
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.
Villanueva, Joan; Grimalt, Joan O.; Cortijo, Elsa; Vidal, Laurence; Labeyrie, Laurent
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.
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)
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