Temporary Migrations of Gulf Stream Water on the Atlantic Seaboard

Analyses of 161 thermograms from vessels on the Boston-Bermuda route illustrate temporary migrations of Gulf Stream water during 1932–1938. A northern limit of Gulf Stream waters, determined by the position of the "cold wall", on this route varies between latitudes 36°41′N. and 40°23′N. Average monthly positions of the northern limit indicate that more southerly positions follow the equinoxes. These mean monthly positions, plotted on a lagging scale, are inversely correlated with average monthly differences in sea level between Bermuda and Charleston, S.C., which inverse correlation indicates that the position of the northern limit is related to current strength, decrease in strength being followed by northerly migrations, and increase by southerly migrations. Hydrographic observations off the Canadian Atlantic coast offer some evidence of the influence of these migrations on the waters of this area.

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Satellite Observations of Seasonal and Interannual Changes of Sea Level and Currents over the Scotian Slope

Journal of Physical Oceanography ◽

10.1175/jpo3036.1 ◽

2007 ◽

Vol 37 (4) ◽

pp. 1051-1065 ◽

Cited By ~ 18

Author(s):

Guoqi Han

Keyword(s):

Sea Level ◽

Gulf Stream ◽

Surface Current ◽

Late Summer ◽

Element Model ◽

Current Strength ◽

Altimeter Data ◽

Late Winter ◽

Shelf Edge ◽

Edge Current

Abstract Seasonal and interannual sea level and current variations over the Scotian slope are examined using 10 years of Ocean Topography Experiment (TOPEX)/Poseidon (T/P) satellite altimeter data. Geostrophic surface current anomalies normal to ground tracks are derived from the along-track gradients of sea level anomalies. The altimetric current anomalies are combined with a climatological mean circulation field of a finite-element model to construct nominal absolute currents. The seasonal mean results indicate that the sea level is highest in late summer and lowest in late winter and that the surface slope circulation is strong in winter/autumn and weaker in summer/spring. The total transport associated with the westward shelf-edge current and with the eastward slope current, calculated by combining the T/P data with a climatological seasonal mean density field, reveals a substantial seasonal change dominated by the barotropic component. The present analysis reveals prominent interannual changes of the sea level and current anomalies for the study period. The sea level was lowest in 1996/97, when the Gulf Stream was in its most southern position. The mean winter circulation over the Scotian slope was strongest (up to 30 cm s−1 in both the southwestward shelf-edge current and northeastward slope current) in 1998 and weakest (weaker and broader shelf-edge current) in 1996, which may be related to the fluctuation of the equatorward Labrador Current strength and of the Gulf Stream north–south position. The study also suggests that the root-mean-square current magnitude is positively correlated with the occurrence of the Gulf Stream warm-core rings (WCRs) on the interannual scale, while WCR yearly mean kinematic properties seem to have small variations.

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FATE OF PETROLEUM COMPONENTS IN ESTUARINE WATERS OF THE SOUTHEASTERN UNITED STATES

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1977-1-611 ◽

1977 ◽

Vol 1977 (1) ◽

pp. 611-616 ◽

Cited By ~ 5

Author(s):

Richard F. Lee

Keyword(s):

Water Samples ◽

Gulf Stream ◽

Atlantic Coast ◽

Low Molecular Weight ◽

Degradation Rates ◽

Polycyclic Aromatic ◽

Benzene Toluene ◽

South Atlantic Coast ◽

Detrital Particles ◽

Stream Waters

ABSTRACT Radiolabeled hydrocarbons and phenols were added to water samples from the Skidaway and Cooper Rivers, two estuarine rivers on the U.S. south Atlantic coast. The adsorption of hydrocarbons to particles and microbial degradation of different petroleum components were the processes studied. Alkanes, low molecular weight aromatics (benzene, toluene, naphthalene and methylnaphthalene) and phenols were rapidly degraded to 14CO2. Low degradation rates were observed for the higher weight polycyclic aromatic hydrocarbons, fluorene, anthracene, benz(a)anthracene, and benz(a)pyrene, and from 12 to 70% of these hydrocarbons were absorbed to suspended particles in the water. Radioauto graphs of particles after the addition of 3H-benz(a)pyrene and 3H-hexadecane to the water samples indicated the hydrocarbons associated with detrital particles. This detritus was composed of a mixture of clay, organic matter, plankton remains and living microbes. One area of the Cooper River had visible oil slicks and the degradation rates of added heptadecane (20 μg/l), naphthalene (30 μg/l) and methylnaphthalene (30 μg/l) were 0.4, 2.8 and 1.1 μg/I/day, respectively. In contrast, at a downstream site, where there were no visible slicks, the degradation rate of these same hydrocarbons were 0.1, 0.7 and 0.1 μg/l/day, respectively. Estuarine water had much higher hydrocarbon degradation rates than offshore and Gulf Stream waters.

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Evolution of marine climates of the U.S. Atlantic coast during the past four million years

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1988.0029 ◽

1988 ◽

Vol 318 (1191) ◽

pp. 661-678 ◽

Cited By ~ 34

Keyword(s):

Sea Level ◽

Late Pleistocene ◽

Gulf Stream ◽

Climatic Variability ◽

Atlantic Coast ◽

High Amplitude ◽

Climatic Conditions ◽

Eastern United States ◽

Sea Level Changes ◽

Isthmus Of Panama

Marine climatic and sea-level changes in the eastern United States show two distinct modes: a gradual, directional Pliocene warming that ended with an abrupt regression, and a quasi-cyclic, high-amplitude, high-frequency middle-late Pleistocene pattern of alternating glacials and interglacials. Pliocene marine sediments of the Duplin Formation, deposited during a period of high sea level between 4.0 and 2.8 Ma BP, contain increasing percentages of tropical and subtropical ostracods, signifying a gradual warming. After maximum warm-water temperatures ca . 3.2-2.8 Ma BP, sea level dropped; this was followed by extensive subaerial erosion between about 2.8 and 2.0 Ma BP. This series of events reflects the emergence of the Isthmus of Panama between about 3.5 and 3.0 Ma BP, concomitant intensification of warm Gulf Stream flow along the eastern U.S.A., and initial Pliocene glaciation in the Northern Hemisphere. In the middle-late Pleistocene, glacial-interglacial cycles occurred with a periodicity of ca . 100 ka. Four (possibly five) emerged interglacial marine sequences correlate with deep-sea oxygen-isotope stages 13/11, 7, 5, and 1. During some interglacials, however, climatic conditions ranged from full interglacial warmth to cool, nearly interstadial conditions; this observation indicates short-term regional climatic variability.

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Western boundary circulation and sea level patterns in northern hemisphere oceans

10.5194/egusphere-egu21-15743 ◽

2021 ◽

Author(s):

Samuel Diabaté ◽

Didier Swingedouw ◽

Joël Hirschi ◽

Aurélie Duchez ◽

Philip Leadbitter ◽

...

Keyword(s):

North America ◽

Sea Level ◽

Gulf Stream ◽

Atlantic Coast ◽

Ocean Dynamics ◽

Western Boundary ◽

Tide Gauges ◽

Sea Level Changes ◽

Coastal Sea ◽

The Kuroshio

The sea level changes along the Atlantic coast of the US have received a lot of attention recently because of an increased rate of rise north of the Gulf Stream separation point since the late 1980s (Sallenger et al., 2012 ; Boon, 2012). While sea-level rise is a major issue for coastal community, sea-level measurements in the region are key to understand the past of the nearby Gulf Stream and the large-scale ocean dynamics. Tide gauges on the coastline have measured the inshore sea-level for many decades and provide a unique window on past oceanic circulation. So far, numerous studies have linked the interannual to multi-decadal coastal sea-level changes to ocean dynamics, including the Gulf Stream strength, the divergence of the Sverdrup transport in the basin interior and the Atlantic meridional overturning circulation. However, other studies argue that local and regional processes, such as the alongshore winds or the river discharges, are processes of greater importance to the coastal sea level.The general picture in the Atlantic is hence unclear. Yet, the northwest Atlantic is not the only western boundary region where sea-level has been well sampled. In this study we extend the analysis to the northwest Pacific, where links between the state of the Kuroshio and sea-level are evident (Kawabe, 2005; Sasaki et al., 2014). We discuss similarities and dissimilarities between the western boundary regions. We show for each basin, that the inshore sea level upstream the separation points is in sustained agreement with the meridional shifts of the western boundary current extension. This indicates that long duration tide gauges, such as Fernandina Beach (US) and Hosojima (Japan) could be used as proxies for the Gulf Stream North Wall and the Kuroshio Extension state, respectively.References:Boon, J. D. (2012). Evidence of sea level acceleration at US and Canadian tide stations, Atlantic Coast, North America. Journal of Coastal Research, 28(6), 1437-1445.&#160;Kawabe, M. (2005). Variations of the Kuroshio in the southern region of Japan: Conditions for large meander of the Kuroshio. Journal of oceanography, 61(3), 529-537.Sallenger, A. H., Doran, K. S., & Howd, P. A. (2012). Hotspot of accelerated sea-level rise on the Atlantic coast of North America. Nature Climate Change, 2(12), 884-888.Sasaki, Y. N., Minobe, S., & Miura, Y. (2014). Decadal sea&#8208;level variability along the coast of Japan in response to ocean circulation changes. Journal of Geophysical Research: Oceans, 119(1), 266-275.

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Arsenic Contamination and its Speciation in the Water System around the Abandoned Dongil Au-Ag Mine in Korea

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.277-279.503 ◽

2005 ◽

Vol 277-279 ◽

pp. 503-509 ◽

Cited By ~ 1

Author(s):

Ji Min Yi ◽

Jin Soo Lee ◽

Hyo Taek Chon

Keyword(s):

Stream Water ◽

Arsenic Concentration ◽

Water System ◽

Arsenic Species ◽

High Concentration ◽

Aqua Regia ◽

Sequential Extraction Analysis ◽

Fe Oxyhydroxides ◽

High Level ◽

Stream Waters

This study was made to investigate the extent and degree of As contamination in waters and sediments influenced by previous mining activity in the abandoned Dongil Au-Ag mine. Arsenic species was also identified in surface waters and groundwater. The chemical form of As in sediments was examined using sequential extraction analysis. The major contamination source of As in the mine area is suggested to be tailings with elevated levels of 8,718 As mg/kg. This was associated with the release of high level of As into the water system in the study area. The pH values of water samples ranged from 7.7 to 10.1, which was neutral to strong alkaline due to buffering effect by high concentration of Ca and Mg dissolved from carbonate mineral and weathering of concrete. Stream waters contained high level of As within the range of 40.5 to 150.4 ㎍/L and most waters exceeded the permissible level (50 ㎍/L) of As for stream water in Korea. The concentration ratios of As(Ⅲ) to As (total), however, extended in the range of 5.8 to 75% and increased at low pH condition in stream waters. Arsenic concentration in sediments digested by aqua regia (HNO3+HCl) ranged from 162 to 2,077 mg/kg. The highest concentration of As may be due to the direct inflow of tailings. The relatively high percentage (17.1~35.3%) of As coprecipitated with amorphous Fe oxyhydroxides indicates that more severe contamination of As can occur by re-extracting due to changes of chemical environment such as reducing condition.

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Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201420140007 ◽

2014 ◽

Vol 86 (2) ◽

pp. 671-683 ◽

Cited By ~ 38

Author(s):

JOÃO WAGNER A. CASTRO ◽

KENITIRO SUGUIO ◽

JOSÉ C.S. SEOANE ◽

ALINE M. DA CUNHA ◽

FABIO F. DIAS

Keyword(s):

Sea Level ◽

Rio De Janeiro ◽

Atlantic Coast ◽

Southeastern Brazil ◽

Brazilian Coast ◽

14C Dating ◽

Relative Sea Level ◽

Coastal Evolution ◽

The Holocene ◽

First Time

The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum level of +2.5 m was reached between 4770 and 4490 cal yr BP. At the point of maximum transgression, the sea-level began a general behavior of lowering until the present. These results confirm other data already obtained elsewhere along the Atlantic coast of South America. The results of this study are consistent with previous researches and they help to refine the Holocene sea-level record along the Brazilian coast.

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Effects of aerosols on precipitation in north-eastern North America

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-5111-2014 ◽

2014 ◽

Vol 14 (10) ◽

pp. 5111-5125 ◽

Cited By ~ 8

Author(s):

R. Mashayekhi ◽

J. J. Sloan

Keyword(s):

North America ◽

Atlantic Coast ◽

Inverse Correlation ◽

Cloud Droplet ◽

Cloud Microphysics ◽

Convective Precipitation ◽

Eastern North America ◽

Anthropogenic Aerosols ◽

Convective Rain ◽

North Eastern

Abstract. The changes in precipitation in north-eastern North America caused by chemistry – and particularly anthropogenic aerosols – are investigated using the Weather Research Forecasting with Chemistry (WRF/Chem v3.2) 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. Total convective rain is greater than total non-convective rain in the domain, but 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, representing the nucleation and accumulation modes respectively. 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 sizes.

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