Northeast Corner Research Articles

On the influence of the parameterization of lateral boundary layers on the thermohaline circulation in coarse-resolution ocean models

Because of the first order geostrophic balance in the ocean interior, the parameterization of lateral boundary layers has more influence than the parameterization of viscosity on the thermohaline overturning and the deep water properties in coarse-resolution ocean circulation models. Different formulations of momentum dissipation and associated boundary conditions are implemented within a planetary-geostrophic ocean circulation model for a Cartesian coordinate, flat-bottomed, β-plane, with restoring boundary conditions for the surface density and zero wind stress. Traditional Laplacian friction with a no-slip boundary condition produces an interior circulation in good agreement with geostrophy and the Sverdrup balance, but generates very large vertical (diapycnal) transports at lateral boundaries, especially upwelling in the western boundary current and downwelling in the northeast corner. The meridional and zonal overturning are thus enhanced, but drive to depth surface waters that are not as cold as the ones in the deep convection regions. Rayleigh friction with various frictional closures for the alongshore velocities within a no-normal-flow boundary condition framework efficiently reduces the diapycnal vertical transports along the boundaries, by allowing horizontal recirculation of geostrophic currents impinging into coasts. Hence, these parameterizations induce weaker overturnings, with colder deep water and a sharper thermocline resulting in higher poleward heat transports. We suggest that the upwelling along the boundaries is a consequence of the coarse-resolution dynamics and not only horizontal diffusion (termed the Veronis effect, horizontal diffusion produces large diapycnal fluxes once the isopycnals are tilted by coastal upwellings). Alternative parameterizations for the lateral boundary layers reduce this effect without the need for rotating the mixing tensor along isopycnals. This model comparison proves the need to clearly assess the extent of the diapycnal upwelling in the western boundary currents and to develop physically-based parameterizations of lateral boundary layers in order to improve coarse-resolution OGCMs.

Structures of Furanosides: Density Functional Calculations and High-Resolution X-ray and Neutron Diffraction Crystal Structures

Highly accurate and precise crystal structures of methyl R-D-arabinofuranoside, methyl ‚-D-ribofuranoside, methyl R-D-lyxofuranoside, and methyl R-D-xylofuranoside have been determined at 100 K by X-ray crystallography. The structures of methyl R-D-arabinofuranoside and methyl ‚-D-ribofuranoside have also been determined at 15 K by neutron diffraction. Equilibrium (re) geometries of the same compounds were computed by means of density functional methods using a variety of exchange-correlation functionals and a sequence of basis sets. The validity of the computed results was assessed by several criteria including agreement between computed and observed bond distances and bond angles, agreement between computed and observed ring conformations, and basis set convergence of the computed geometrical parameters. Particular reference was made to computed internal hydrogen bond parameters, which are especially sensitive to the quality of the theoretical treatment. Because of the intrinsic sensitivity of the conformation of the five-membered ring to bond lengths and bond angles, molecular mechanics and small basis set SCF treatments are wholly inadequate. Local density functional theory also fails because of a tendency to strongly underestimate internal hydrogen bond distances. When the B3LYP exchange-correlation functional is used, bond lengths and bond angles agree with the neutron diffraction values to within their experimental uncertainty and the ring conformation is qualitatively correct, as long as a basis set of at least double- œ plus polarization quality (such as cc-pVDZ) is used. Further expansion of the basis set leads to more accurate equilibrium bond lengths and bond angles but does not appreciably affect the ring conformation. For methyl R-D-arabinofuranoside, methyl ‚-D-ribofuranoside, and methyl R-D-xylofuranoside, there is very good correspondence between the best computed and observed ring conformations, even though some intermolecular hydrogen bonds in the crystal give way to internal hydrogen bonds in the predicted gas-phase structures. On the other hand, in the case of methyl R-D-lyxofuranoside, an O2H‚‚‚O4 internal hydrogen bond between the ring oxygen O4 and the hydroxyl hydrogen of a ring carbon (O2H) in the computed structure leads to a very large change of ring conformation from the northeast corner of the pseudorotation pathway (P ) 28°, crystal) to the southeast corner ( P ) 130°, computed).

Micro-spatial variability of soil nitrate following nitrogen fertilization and drip irrigation

Micro-spatial analysis of nitrate (NO3), an environmental contaminant partially attributed to nitrogen fertilization, can be useful for estimating its distribution in soils. A study was conducted to determine the micro-spatial distribution of soil NO3 using kriging and cokriging in a drip-irrigated and nitrogen-fertilized field. One hundred soil samples were collected in a regular grid pattern from a 10 m × 20 m plot, and analyzed for soil NO3 and pH. The effect of reduced sample size on NO3 estimation was also evaluated. The pH data indicated the soils were slightly acidic to neutral with log[NO3] values ranging from 1.66 to 2.95. These parameters were inversely related; which was probably an attribute of soil nitrification process. Sample variograms and cross-variograms suggested that the spatial distribution of pH and log[NO3] could be described by linear models in the area studied, as indicated by small MSE (mean sum error), and RKV (reduced kriging variance) values close to 1. Contour maps based on kriging and cokriging estimates indicated greater homogeneity of the variables in the south-north direction than the east-west, except for zones of high NO3 and low pH in the north-central edge and north-east corner of the grid area. Cokriging of log[NO3] estimation, using pH data, improved MSE, MSSE (mean sum square error), MKV (mean kriging variance), RKV, CEE (correlation between estimated data and error), CEM (correlation between estimated and measured data) by 46, 31, 30, 22, 96, and 98%, respectively, as compared to kriging. Lower cokriging variance for any estimated log[NO3] value, as compared to the kriging analysis, indicated that cokriging provided more accurate estimates. With reduced sample observations (n) for NO3 similar conclusions were obtained; and the estimation accuracy was maintained up to n >70. Cokriging analysis with reduced n also curtailed the analytical cost, and facilitated NO3 estimation by means of pH, which was measured at a cheaper cost.

Forest Pact Bypasses Computer Model

AUSTRALIAMELBOURNE, AUSTRALIA-- Conservation scientists are reeling from the outcome of a fight over one of Australia's richest regions of biodiversity. An innovative and internationally praised scheme for reconciling conflicts over natural resources that tapped a 3-year, $23 million biota survey proved no match this fall for old-fashioned political muscle. The result was a bill passed late last month by state legislators permitting extensive logging in diverse forest ecosystems in the northeast corner of the state of New South Wales.

Pollution history of a tropical estuary revealed by combined hydrodynamic modelling and sediment geochemistry

Hydrodynamic modelling of water movement in Hunts Bay, a protected part of Kingston Harbour, Jamaica, shows that depth averaged tidal flows are very low. In the northeast corner of Hunts Bay, water is essentially stagnant. Even under high flow conditions, much of the Bay bottom water is `bypassed' by buoyant, lower salinity surface flows. The muddy sediments of Hunts Bay reflect these sluggish to stagnant conditions; sediment cores from the northeast corner of the Bay contain progressively higher amounts of organic matter in their upper parts (∼last 15–20 years sedimentation). Combined C/N ratios and stable carbon isotope compositions of this organic matter imply a sewage origin. Both lead and chromium metal concentrations and enrichment factors relative to average crustal shales show geographically related patterns that reflect hydrodynamic circulation predicted by modelling. In particular, metal concentrations and enrichment factors are highest at the northern end of the bay, especially in the northeast corner. Modelling confirms that stagnant conditions would occur in the northeast part of the bay even without the presence of a major causeway. The causeway may contribute to low flow conditions, but is not the principal cause of organic contamination, which is simply an excessive input of sewage.

Geophysical interpretation of tectonic features in Bangladesh

Bangladesh occupies the major part of the Bengal basin. It is mainly a plain fluvi-dieltaic land. Except the eastern and northeastern Tertiary hilly region, the whole country is covered with thick Quaternary sediments.
 Tectonic features in Bangladesh, except the eastern and northeastern hilly structures, are hidden under thick cover of sediments. Gravity anomalies dearly show the locations of major subsurface tectonic features of the country, namely a) Himalayan foredeep, b) Rangpur platform, c) Hinge zone, d) Surma basin and e) Bengal foredeep. Magnetic anomalies and the seismic sections also support the gravity results.
 Shape, extent and depth of the tectonic features in Bangladesh are interpreted from geophysical data, particularly from the gravity data supported by available geological and drilling information. Interpretation shows that the Rangpur platform, situated in the northwestern Bangladesh, is the shallowest subsurface tectonic feature in the country. The northern part of the Rangpur platform slopes down to the Himalayan foredeep and the southern part to the Hinge zone. The Surma Basin, containing very thick sediments, lies in north-east corner of the country; and the Bengal foredeep, the most extended tectonic feature, occupies the southern deltaic part of the country. The Fold Belt, the only exposed tectonic feature, lies in the eastern and northeastern hilly region of the country.

Evolution of the Gorda Escarpment, San Andreas Fault and Mendocino triple junction from multichannel seismic data collected across the northern Vizcaino block, offshore northern California

The Gorda Escarpment is a north facing scarp immediately south of the Mendocino transform fault (the Gorda/Juan de Fuca‐Pacific plate boundary) between 126°W and the Mendocino triple junction. It elevates the seafloor at the northern edge of the Vizcaino block, part of the Pacific plate, ∼1.5 km above the seafloor of the Gorda/Juan de Fuca plate to the north. Stratigraphy interpreted from multichannel seismic data across and close to the Gorda Escarpment suggests that the escarpment is a relatively recent pop‐up feature caused by north‐south compression across the plate boundary. Close to 126°W, the Vizcaino block acoustic basement shallows and is overlain by sediments that thin north toward the Gorda Escarpment. These sediments are tilted south and truncated at the seafloor. By contrast, in a localized region at the eastern end of the Gorda Escarpment, close to the Mendocino triple junction, the top of acoustic basement dips north and is overlain by a 2‐km‐thick wedge of pre‐11 Ma sedimentary rocks that thickens north, toward the Gorda Escarpment. This wedge of sediments is restricted to the northeast corner of the Vizcaino block. Unless the wedge of sediments was a preexisting feature on the Vizcaino block before it was transferred from the North American to the Pacific plate, the strong spatial correlation between the sedimentary wedge and the triple junction suggests the entire Vizcaino block, with the San Andreas at its eastern boundary, has been part of the Pacific plate since significantly before 11 Ma.

Oceanographic conditions east of Iceland

Circulation and hydrography on the shelf east of Iceland and on the western portion of the Iceland‐Faeroe Ridge is described by a series of surveys using temperature‐salinity profilers, moored current meters and satellite‐tracked drifters. The dominant surface current of the region is the northeastward flow of North Atlantic Water at the shelf break southeast of Iceland as it leaves the shelf to join the Iceland‐Faeroe Front. On the bottom beneath it flowing in the opposite direction is a strong, steady current composed of water from the Nordic Seas that has overflowed the ridge and followed along bathymetric contours. North of the front, three comparatively weak currents are identified, formed by splitting of the North Icelandic Irminger Current after it has rounded the northeast corner of Iceland. One branch, the East Icelandic Current, is confined to the shelf and produces a mean, southward flow until it turns eastward to join the Iceland‐Faeroe Front. Another leaves the shelf to form the shallow, southeastward flowing Icelandic Current. The third follows deeper contours of the continental slope and renews waters on the northern flank of the Iceland‐Faeroe Ridge.

The Deanery, Windsor Castle

For almost six and a half centuries, the wardens (and later the Deans) of St George's Chapel have been lodged in the extreme north-east corner of the Lower Ward at Windsor Castle. From fairly modest beginnings, the house developed into a much grander building, after the construction of a huge new chapel in the late fifteenth century. After the Elizabethan settlement it developed further and was a childhood home of Sir Christopher Wren, before being vandalized in the Commonwealth period. Following the Reformation, it was reconstructed and then given a grand new front in 1710 for the first of a series of aristocratic Deans. The final major rebuilding was carried out in 1831 immediately after the demise of George IV, and the house was used by Queen Victoria as a sort of ‘confessional’ and very private access to the royal pew after her widowhood. Today it is still a fine house after being reduced in size for twentieth-century Deans who do not have large families and many servants. Its rendered south front can still be seen immediately behind the buttressed east end of the Albert Memorial Chapel (fig. 1).

Bay of Bengal currents during the Northeast Monsoon

Velocity and property observations were made during February and March 1995 as part of the World Ocean Circulation Experiment (WOCE) Hydrographic Program (WHP) expedition in the Indian Ocean. The observed circulation in the upper 300 m of the ocean during the northeast monsoon is compared to the output of a high‐resolution, 3‐layer, nonlinear model forced by European Center for Medium Range Weather Forecasting (ECMWF) winds. The data identify several new features in the Bay of Bengal: a shelf‐break coastal current in the northeast corner, an eddy and subsurface jet near the South Preparis Channel, and an eastward countercurrent extending from 80°E to the eastern boundary. The countercurrent transports high‐salinity surface water from the northwest Indian Ocean into the bay, and separates the historically observed North Equatorial Current into two currents with separate sources and water properties. The data also detail the spatial structure of the South Equatorial Current and Countercurrent, and show the Equatorial Undercurrent in the eastern half of the Indian Ocean. The model compares well enough with the data to suggest that such realistic models may provide a useful temporal context for the WHP snapshot.

Joint Spanish‐American Research uncovers fracture pattern in northeastern Caribbean

A joint Spanish‐American geophysical cruise north of the Virgin Islands has delineated the fracture pattern of the North American plate as it is overrun by the northeast corner of the Caribbean plate. Previously known fractures parallel to the plate boundary (approximately east‐west) probably result from plate flexure, while newly defined crossing fractures (north‐northeast) may be related to extension produced by the compound bend of the North American plate. The direction of the fractures may be modified by preexisting spreading tectonic fabric.The fieldwork took place in May 1997 aboard the Spanish research vessel Hespérides as part of an ongoing effort to study plate interactions and their seismotectonic effects on Puerto Rico and the Virgin Islands. Multichannel seismic‐reflection profiles, multibeam bathymetry, and gravity and magnetic data were collected on the cruise. Also examined were reprocessed regional seismic lines, newly relocated earthquake epicenters, and satellite gravity data. The program was planned by scientists from the U.S. Geological Survey (USGS), Instituto Español de Oceanografía (IEO), and the Woods Hole Oceanographic Institution.

In‐situmeasurement of soil moisture at the KUREX‐91 Streletskaya steppe sites

Measurements were obtained at Kursk Biospheric Reserve Station (BRS) throughout the period from 6 July through 27 July, 1991. Both gravimetric and dielectric measurements were obtained daily for all sites on the steppe. Soil sampling points were selected near each corner of the three sites (i.e. southeast, southwest, northwest, and northeast field corners). This scheme was slightly modified for the primary site, field 12, to achieve better coincidence with Soviet measurements. The moisture content of the top 10 cm of soil was examined by extracting a cylindrical core approximately 2cm in diameter and 10cm long at four sampling locations in each of the three test sites/fields. Two cores were extracted from each sampling location and combined in a single sampling container for subsequent gravimetric analysis. These samples were weighed in the laboratory several hours after being obtained and placed in drying ovens at a temperature of 110°C for approximately 48 h. Dry weights were then obtained and the origi...

The Deanery, Windsor Castle

For almost six and a half centuries, the wardens (and later the Deans) of St George's Chapel have been lodged in the extreme north-east corner of the Lower Ward at Windsor Castle. From fairly modest beginnings, the house developed into a much grander building, after the construction of a huge new chapel in the late fifteenth century. After the Elizabethan settlement it developed further and was a childhood home of Sir Christopher Wren, before being vandalized in the Commonwealth period. Following the Reformation, it was reconstructed and then given a grand new front in 1710 for the first of a series of aristocratic Deans. The final major rebuilding was carried out in 1831 immediately after the demise of George IV, and the house was used by Queen Victoria as a sort of ‘confessional’ and very private access to the royal pew after her widowhood. Today it is still a fine house after being reduced in size for twentieth-century Deans who do not have large families and many servants. Its rendered south front can still be seen immediately behind the buttressed east end of the Albert Memorial Chapel (fig. 1).

Characterization of the principal tidal current constituents on the Texas‐Louisiana shelf

We analyzed 81 current meter records of varying lengths (3 to 30 months) to describe the principal diurnal (O1, K1, P1, and Q1) and semidiurnal (S2, M2, K2, and N2) tidal current constituents on the Texas‐Louisiana continental shelf. The Louisiana‐Texas Shelf Physical Oceanography Program (LATEX) had 81 current meters at 31 sites and varying depths from April 1992 to December 1994. The local inertial period range across the shelf (24.4 hours to 26.2 hours) and thermal diurnal cycling during the summer season make it difficult to estimate the diurnal tidal constituents. Dominant tidal modes on the shelf are K1, O1, and M2. Absolute and relative energy contained in each tidal constituent varies with shelf location. The northeast corner of the shelf, near Atchafalaya Bay, has the largest tidal currents with maximum surface current amplitudes (at 3 m depth) of about 9 cm s−1, while typical maximum tidal surface currents near the shelf break are between 1 and 2 cm s−1 for each of the K1, O1, and M2 components. In general, the surface tidal currents decrease in magnitude as water depth increases toward the shelf break, although the semidiurnal components are amplified more at midshelf locations than the diurnal components. Examination of tidal ellipses at different depths suggests that the M2 tide has less vertical structure, while the diurnal tides exhibit more shear, particularly at the more shallow locations. Sea surface height constituents estimated at five locations along the Texas‐Louisiana coast are in agreement with historical values.

The influence of the mean state on interdecadal variability in flat-bottomed ocean models

It has been well-demonstrated that many flat-bottomed ocean models possess interdecadal oscillatory solutions. Recently, propagation of viscous (or coarsely resolved) Kelvin waves around the boundary has been implicated in the oscillations. In this paper, we examine how the mean state affects the character of the oscillation. We find that the stratification along the northern boundary has a large effect upon the oscillation. Mean states with an essentially unstratified north-east corner, lead to long period oscillations as the viscous boundary wave slowly crosses the northern boundary. Conversely, mean states with a stratified north-east corner, but unstratified north-west corner, lead to short-period, but larger-amplitude, oscillations since boundary wave propagation is arrested only in the north-west corner.We demonstate that the different character of oscillations under different zonal redistributions of a diagnosed flux are a consequence of the different mean states induced by the redistribution.

Citrus Cutworm Insecticide Efficacy Trials, 1997

Abstract Two insecticide efficacy trials for the control of citrus cutworm were conducted in 1997. In the first experiment, three formulations of Bacillus thuringiensis were tested and compared with a water (check) spray in a commercial block of 32-year-old ‘Washington’ navel orange trees of Exeter Farms, Exeter, California. Applications of MYX 300, MYX 324, and CRYMAX WDG were made on 8 Apr using a Bean hand-sprayer at approximately 300 gpa, 300 psi. In the second experiment, two rates of RH-5992 70 WP and one rate of RH-2485 80WP, each combined with the surfactant Latron CS-7, and a treatment of Spinosad 2SC were compared to a water control spray in a block of 14-yr-old ‘Washington’ navel oranges at the Lindcove Research and Extension Center, Exeter, California. The applications were made on 11 Apr using the same equipment, rate, and pressure as the Exeter Farms test. In both experiments, eight replicated single-tree treatments were used and treatments were assigned on the basis on pre-treatment sampling of larvae. Larvae were collected by placing a canvas beating sheet (112 cm X 75 cm) beneath the outside foliage of the tree and vigorously shaking the foliage 10 times. Citrus cutworm larvae falling on the canvas were counted and recorded, then returned to the foliage. Pre-treatment larval counts involved sampling the Northeast and Southwest corners of the trees at Exeter Farms on 7 Apr and at Lind-cove on 4 Apr. All four tree quadrants were sampled for post-treatment larval counts on 15 Apr and 22 Apr at Exeter Farms; and on 18 Apr and 25 Apr at Lindcove.

An Inner and Outer Gate Complex at Tell en-Nasbeh

At Tell en-Nasbeh (Mizpah), W. F. Bade uncovered a two-chamber gate at the northeast corner of the site and a four-chamber gate on the east side. The relationship of these gates to each other, and to the offset-inset wall of King Asa of Judah, has puzzled scholars. Most have assumed that the four-chamber gate was never completed or only functioned as the settlement's gate until an Assyrian destruction in 701 B. C. It is more likely that the two gates are a single, Inner-Outer Gate complex, built by Asa in the ninth century B. C., which functioned until the Babylonian destruction of Jerusalem in 586, after which the four-chamber gate was replaced by new constructions associated with the transformation of Mizpah into an administrative center under Gedaliah. The two-chamber gate functioned until the fifth century B. C. Fresh evaluations of the topography in the intergate area, the site's stratigraphy and in situ ceramic deposits are marshaled to support this theory.

The square compass rose: the evidence from Taiwan

The ‘compass rose’ is a strikingly geometrical pattern that appears when daily stock returns are plotted against themselves with one day's lag. It is characterized by evenly spaced lines radiating from the origin with the thickest lines pointing in the major directions of a compass. This study uncovers the existence of a new type of compass rose not seen previously that is embedded within several overlapping square patterns. Furthermore, the ‘square’ compass rose patterns documented in this study are not quite as radially symmetrical as those studied by previous researchers in that there exists considerable clustering in the north-east and south-west corners of the square patterns. Finally, previous researchers who examined the compass rose assert that the compass rose does not contribute any additional information and cannot be used to enhance predictability. Contrary to the beliefs of previous researchers, this study demonstrates that the compass rose pattern in the individual stock returns can be used to improve stock return forecasts within an ARMA-GARCH framework. In all cases examined in this study, ARMA-GARCH models that make use of information contained in the compass rose produce improved forecasts compared to identical models that do not incorporate the information contained in the compass rose.

Age and paleoecological significance of an early postglacial fossil assemblage near Marathon, Ontario, Canada

Organic materials recovered from deltaic deposits confined to the Black River Valley near Marathon, Ontario, provide information on lake-level history and local ecology for the region. Radiocarbon samples provide the first age determinations (ca. 8200 BP) for the post-Minong III – IV lake phases along the northeast corner of the Lake Superior basin. A minimum of 49 Coleoptera taxa and 22 vascular plant taxa indicate coniferous-forest and riparian communities. Overbank deposition along rivers flowing from the ice margin provided temporary ponds colonized by sedges and other aquatic plants and animals. Many records for both animals and plants illustrate occurrences of western and Arctic disjunct species in early Holocene time. Some "western" Coleoptera might still be present as disjuncts in the Marathon region.

From Child Development to Community Development: One Agency's Journey

Sheldon Park is a public housing community in the northeast corner of Allegheny County 25 miles from downtown Pittsburgh, Pennsylvania. It consists of 192 units of back-to-back townhouses situated on both sides of an oval road winding through the housing community. Most buildings contain four to six townhouses. The community has large grassy areas with shade trees at the front and back of each unit. In the center of the community is the Community Building, a one-story structure with a large, open activity area, a kitchen, and several meeting rooms.