mid-Atlantic Coast Research Articles

Intertidal and Littoral Ecosystems.

1. Introduction (P.H. Nienhuis and A.C. Mathieson). 2. Physical Characteristics of Littoral Ecosystems, with Special Reference to Marine Plants (K. Luning and R. Asmus). Temperature. Light. Water motion and other physical factors. References. 3. Chemical Characteristics of Marine Littoral Ecosystems (W. Schramm). Introduction. Import and export processes and chemical characteristics. The influence of non-biological processes on chemical characteristics. Biological activity and chemical parameters. References. 4. Vertical Distribution (G. Russell). Zonation. The supralittoral zone. The eulittoral zone. The sublittoral zone. Causes of zonation. References. 5. Shoreline Ecology in Iceland, with Special Emphasis on the Benthic Algal Vegetation (I.M. Munda). Introduction. Geological history. Abiotic environmental factors. Vegetation patterns and species distribution. References. 6. The Baltic Sea Gradient (I. Willentinus). Introduction. A brief qualitative description of the littoral ecosystem. Communities on rocky substrates. Littoral communities on sandy and muddy substrates. Biomass distribution. Functional aspects of the littoral system. Acknowledgements. References. 7. Northwest Atlantic Rocky Shore Ecology (A.C. Mathieson, C.A. Penniman and L.G. Harris). Introduction. Abiotic environment. Biogeography. Community patterns of open coastal rocky ecosystems: littoral and sublittoral zones. Organization of open coastal rocky ecosystems: littoral and sublittoral zones. Primary productivity of benthic communities. Appendix I: Gulf of Maine. Appendix II: Bay of Fundy. Appendix III: Atlantic coast of Nova Scotia. Appendix IV: Gulf of St. Lawrence. Appendix V: Newfoundland. Acknowledgement. References. 8. Littoral and Intertidal Systems in the Mid-Atlantic Coast of the United States (R.J. Orth, K.L. Heck Jr. and R.J. Diaz). Introduction. Physical setting and sediments. Environmental variables. Faunal and floral characteristics. Functional relations. Acknowledgement. References. 9. The Tropical Western Atlantic Including the Caribbean Sea (C.J. Dawes, E.D. McCoy and K.L. Heck, Jr.). Introduction. Physical Characteristics. Floristic Studies. Faunistic Studies. Communities. Photosynthesis and productivity. Grazing and food webs. References. 10. Open Coast Intertidal and Shallow Subtidal Ecosystems of the Northeast Pacific (M.S. Foster, A.P. De Vogelaere, J.S. Oliver, J.S. Pearse and C. Harrold). Introduction. Abiotic environment. Biogeography. Open coast rocky intertidal ecosystems. Rocky subtidal ecosystems. Sandy intertidal and subtidal beaches. Energetics and trophic relationships. Acknowledgement. References. 11. Southern California Rocky Intertidal Ecosystems (M.M. Littler, D.S. Littler, S.N. Murray and R.S. Seapy). Introduction. Community composition and structure. Primary productivity and functional form relationships. Energetic and food-web relationships. Environmental aspects. Human influences. References. 12.

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part V: The Role of an Upper-Level Front in the Generation of a Rainband

Abstract The origins of a rainband of moderate intensity that occurred over the eastern Carolinas is investigated. It is concluded that the band formed in the updraft portion of a thermodynamically direct vertical circulation about an upper-level frontal zone in a region of conditional symmetrical instability (CSI). The release of CSI is presumed to have been responsible for the dimensions of the band and its orientation relative to the shear vector. An adiabatic mechanism for destabilization of the environment of the upper-level front to CSI was explored but found to be insignificant in this case.

Rain rate statistics and fade distributions at 20 and 30 GHz derived from a network of rain gauges in the mid-Atlantic coast over a five year period

The authors examine five years of rain rate and modeled slant path attenuation distributions at 20 and 30 GHz derived from a network of ten tipping bucket rain gauges located on the mid-Atlantic coast of the US in the vicinity of Wallops Island, VA. Distributions are derived from the variable integration time data from 1-min averages or rain rate time series. It is demonstrated that for realistic fade margins at 20 GHz and above, the variable integration time results are adequate to estimate slant path attenuations using models which require 1-min averages. An accurate empirical formula is developed to convert the variable integration time rain rates to 1-min averages. Rain rate and fade distributions corresponding to the overall network average, yearly network average, and site distributions averaged over the five-year period are derived. Significant differences in the distributions are noted for the year-to-year (temporal variability) and the worst year site-to-site (spatial variability) cases. >

The Iroquois and the World's Rim: Speculations on Color, Culture, and Contact

CONTACT BETWEEN THE PEOPLES of the New World and of the Old World had ideational consequences for both. The event of Contact, and more importantly the process of Contact, initiated the reciprocal redefinition of the mythical realities which for centuries, if not millennia, had structured New World and Old World thoughts and behaviors about the other world. Neither the event nor the process of Contact are over. For the Iroquois, dwelling beneath the Great Tree at the center of Earth-Island, indirect knowledge of Contact at the eastern World's Rim and the indirect receipt of exotic trade goods emanating there, appear to have reified and reinvigorated the traditional ritual meanings and functions of light, bright (reflective), and white things. Not least among these were white marine shell and red, upper Great Lakes native copper, into whose meanings and functions were incorporated and assimilated analogous European trade goods of glazed ceramic, glass, and metal. This seemingly innocuous exchange of European baubles, bangles, and beads along the mid-Atlantic Coast of northeastern North America during the sixteenth century catalyzed profound changes in the ideational, sociopolitical, and economic subsystems of coastal and interior native populations. At the turn of the sixteenth century the indigenous populations of northeastern North America were either Algonquian, Northern Iroquoian, or Siouan speakers (c.f. Trigger 1978). The latter were by far in the minority and were found nearer the mid-Atlantic coast, while the majority were speakers of diverse Algonquian languages. With the exception of the Meherrin, Nottaway, and Tuscarora of the coastal Virginia and Carolina regions to the southeast and the socalled St. Lawrence Iroquoians to the northeast, the remaining Northern Iroquoian speakers dwelt in the interior in what is now north central Pennsylvania, western and central New York, and southwestern Ontario, bordering the Great Lakes of Erie and Ontario. These northern Iroquoian speakers have since been linguistically differentiated into eleven regional populations, which with caution can be identified with as many historically attested geosociopolitical entities, or tribes (nations), bearing the same linguistic identifiers (c.f. Lounsbury 1978; Trigger 1978: 282-289, 357-417, 466-524). Caution

Dimension statistics of rain cell cores and associated rain rate isopleths derived from radar measurements in the mid-Atlantic coast of the United States

Employing a multi-year radar database of precipitation in a mid-Atlantic coast region, the authors have characterized rain cell size statistics. The measurements were made with a high resolution, high power radar in which equicircle diameter contours of resolutions of 1 km and greater were identified out to ranges of 100 km from the radar. The rain cell was constructed by its core intensity isopleth and a family of enveloping contours having defined rain rate intervals in the regions between them. The isopleth statistics were extracted from a database of cores with rain level number 7 (18-24 mm/h) and greater.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part IV: Retrieval of the Thermodynamic and Cloud Microphysical Structures of a Frontal Rainband from Doppler Radar Data

Abstract The thermodynamic and cloud structure of a relatively weak wintertime frontal rainband are derived from dual-Doppler radar measurements, soundings and high resolution surface observations, and with a cloud model. These derivations are simplified by the high degree of two-dimensionality and steadiness of the rainband. Water vapor, cloud water, cloud ice, rain, and snow are parameterized in the cloud model, subject to a temperature distribution that is constrained to a dynamical balance. Air temperature is derived from buoyancy, which is retrieved from the airflow assuming momentum and heat balance. The results of the thermodynamic and cloud microphysical retrieval are compared with airborne measurements in the rainband. The analysis indicates that the rainband was driven by a weak cold front aloft (CFA), which made the prefrontal air conditionally symmetrically unstable. The CFA appeared as a midlevel intrusion of cold, dry air on the mesoγ scale. The CFA interacted dynamically with the planetary ...

Range Dynamics of Hudson River Striped Bass along the Atlantic Coast

We analyzed the movements of Hudson River striped bass Morone saxatilis along the Atlantic coast from the results of a tagging program conducted in the Hudson River estuary between 1984 and 1988. Almost 30,000 striped bass were marked with internal anchor tags; most measured between 200 and 800 mm total length (TL). Interpretations of recoveries are conditional because the distribution and selectivity of fishing effort along the Atlantic coast are unknown. The proportion of total recaptures from outside the Hudson River increased significantly with fish length and by season from spring through autumn. The geographic range of recoveries extended from the Bay of Fundy, Nova Scotia, to Cape Hatteras, North Carolina – a coastal range of about 1,500 km. Most fish recaptured in spring had traveled north and east; recoveries from south of the New York Bight were uncommon until autumn. Many recaptures came from tributaries; far northern recaptures, in particular, tended to occur in rivers or near river mouths. Mean monthly distances between the Hudson River and recapture sites were highest from June through October and increased significantly with fish length. Comparisons with previous studies suggested that the effective coastal range of Hudson River striped bass has expanded since midcentury, especially that of 200–400-mm TL fish. Recapture of a Hudson River-tagged striped bass off Cape Hatteras supports previous winter trawling studies that suggested that large Hudson River striped bass join schools of mixed origin that winter off the mid-Atlantic coast.

Spawning Season and First-Year Growth of Adult Bluefish from the New York Bight

Bluefish Pomatomus saltatrix in the western north Atlantic spawn in the South Atlantic Bight in spring and the Mid-Atlantic Bight in summer. We performed back-calculations to length at age 1 from scales of fish captured during June–September 1986 and 1987 from Long Island, New York, to determine if spring- and summer-spawned fish could be identified among summer-spawning adults captured in the New York Bight. Analysis of gonads confirmed that the summer spawning season off New York is a temporally distinct event occurring from late June to late August, with peak activity in July. All fish used for back-calculations were in spawning condition, and most had lengths at age 1 characteristic of a spring birth date (mean length, 26.5 cm). This observation does not support the hypothesis that spring and summer spawners are two different stocks of fish. Contemporary stocks of adult bluefish along the mid-Atlantic coast may consist largely of spring-spawned fish.

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of theUnited States. Part III: The Evolution of a Middle-Tropospheric Cold Front

Abstract The development of a complex middle-tropospheric frontal structure, the various weather associated with itsprogression across the United States, and its role in the production of precipitation in the eastern third of theUnited States are examined. The frontal structure consisted of two features: a middle-tropospheric cold front associated with a strong 500mb short wave that moved eastward from the Pacific Ocean, and a leeside warm front that formed in a northwardsloping zone of warm-air advection associated with a trough in the lee of the Rocky Mountains. The middletropospheric cold front overtook the leeside warm front to produce a warm occlusion-like structure'in the middletroposphere. As this system progressed eastward across the United States precipitation (from light rain to convectiveshowers) occurred along the leading edge of the middle4ropospheric frontal zone, well ahead of a decayingsurface trough. This study highlights the importance of middle-tropospheric frontal structures in the org...

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part III: The Evolution of a Middle-Tropospheric Cold Front

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part III: The Evolution of a Middle-Tropospheric Cold Front

Spatial variability of rain rate and slant path attenuation distributions at 28 GHz in the mid-Atlantic coat region of the United States

Rain rate and corresponding estimated slant-path attenuation distributions derived from two years of measurements are presented for a network of nine rain-gauge sites located in a region whose extent is 70 km north-south and 47 km east-west in the mid-Atlantic coast of the United States in the vicinity of the NASA (US National Aeronautics and Space Administration) Wallops Flight Facility, Wallops Island, VA. The network average rain-rate distribution was compared with a previously measured six year average at one of the site locations. Agreement in rain rates was found to be within approximately 1 mm/h over the percentage range of 1-0.01% of the year, signifying the constancy of the rain-rate climatology for the region, and implying an ergodic rainfall process. Slant-path attenuation statistics were estimated at 28.56 GHz by interfacing the measured rain-rate distributions at each of nine site locations with Crane's Global Model. >

The chemistry of a mesoscale rainband

AbstractA diagnostic modelling study is presented of the chemistry of a cold‐frontal rainband observed on the mid‐Atlantic coast of the United States. Both the chemical and physical data sets were sufficient to allow realistic evaluation of the 2‐D model employed. Utilizing the model, assessment is made of the importance of in‐cloud chemical processes to the deposition on the ground of selected trace chemicals; in‐cloud sulphate production was found to be of great importance. The effects of the rainband on the vertical transport of trace chemicals, and the effects of precipitation‐formation mechanisms on chemical scavenging, are also discussed.

The chemistry of a mesoscale rainband

A diagnostic modelling study is presented of the chemistry of a cold-frontal rainband observed on the mid-Atlantic coast of the United States. Both the chemical and physical data sets were sufficient to allow realistic evaluation of the 2-D model employed. Utilizing the model, assessment is made of the importance of in-cloud chemical processes to the deposition on the ground of selected trace chemicals; in-cloud sulphate production was found to be of great importance. The effects of the rainband on the vertical transport of trace chemicals, and the effects of precipitation-formation mechanisms on chemical scavenging, are also discussed.

Fishes and Decapod Crustaceans of Cape Cod Eelgrass Meadows: Species Composition, Seasonal Abundance Patterns and Comparison with Unvegetated Substrates

Bimonthly trawl samples from eelgrass and nearby unvegetated areas on Cape Cod, Massachusetts, showed greater species richness in eelgrass meadows relative to unvegetated areas, and greater summer abundance in vegetation for decapod crustaceans and fishes. The composition of eelgrass-associated decapods and fishes was dominated by cold-water taxa and was strikingly different from that of the better studied eelgrass meadows of the mid-Atlantic coast. Four of the eight decapod species collected, including the second and third most abundant taxa, do not even appear in collections reported from Chesapeake Bay eelgrass meadows. Similarly, 10 of the 22 fish species taken, including the first and sixth most abundant species, are not reported from Chesapeake Bay eelgrass samples. Cape Cod eelgrass beds seem to play a nursery role for several commercially important fish species, although the nursery function is less obvious than in previously studied mid-Atlantic eelgrass meadows.

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part I: Synoptic Evolution of a Frontal System from the Rockies to the Atlantic Coast

Abstract The frontal structure of a cyclone that developed in the lee of the Rocky Mountains and moved eastward across the United States is examined. The evolutions and interactions of three frontal features are traced: the primary cold front, a shallow secondary arctic front, and a leeside trough. The zone of warm advection associated with the lee trough became more concentrated with time, and eventually resembled a warm front. The primary cold front had a tipped-forward structure, with cold advection aloft preceding cold advection at lower levels. This front overran the trough to form on the East Coast a structure that was similar to a warm occlusion or a split cold front. Two rainbands, parallel to and approximately 225 km ahead of the surface front, formed and dissipated within the inner network of the Genesis of Atlantic Lows Experiment. These rainbands developed at the leading edge of cold advection aloft, and they dissipated as they approached a region of strong convection over the Gulf Stream. Thi...

Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part II: The Mesoscale and Microscale Structures of Some Frontal Rainbands

Abstract The mesoscale and microscale structures of the clouds and precipitation associated with a frontal system on the mid-Atlantic Coast of the United States are investigated using radar reflectivity and Doppler velocity data, surface mesonet, conventional surface, upper-air and microphysical data. The frontal structure showed similarities to a warm occlusion, with code-air advection aloft preceding cold-air advection at lower levels. Six rainbands were observed in association with the frontal system. All of these rainbands developed within the region of coverage of the NWS WSR-57 radar at Cape Hatteras, North Carolina. Two were upper-level features, associated with a prefrontal surge of cold air and the main push of cold dry air aloft. These rainbands were similar in structure to prefrontal surge and wide cold-frontal rainbands, respectively, observed on the Pacific Northwest Coast. The microphysical and small mesoscale structures of the wide cold-frontal rainband are examined. Three of the rainbands ...

Statistical Modeling of Storm Counts

Abstract A statistical model is presented of a recently compiled record of monthly extratropical storm counts for the mid-Atlantic coast of the United States for the period 1942–83. The counts are modeled as a Poisson process with nonstationary mean function. The mean function is decomposed into a secular component and a seasonal cycle. Because the form of the secular component is unknown, a nonparametric regression approach suitable for Poisson data is used to estimate it. The estimated secular component is generally constant through the 1950s, then declines through the 1970s. The estimate is found to be statistically significant. A Fourier series involving two harmonics is fit to the seasonal cycle. A preliminary check indicates that the seasonal cycle remains stable through time. Some diagnostics based on suitably defined residuals are presented that generally confirm the goodness-of-fit and distributional assumptions underlying the model.

Comparisons of sulfate and nitrate production in clouds on the mid-Atlantic and Pacific Northwest Coasts of the United States

Measurements are presented of sulfate and nitrate production in clouds on the East and West coasts of the United States. Sulfate production measured on the mid-Atlantic Coast was significantly greater than on the Pacific Northwest Coast. Nitrate production was significant on the mid-Atlantic Coast but, on average, insignificant on the Pacific Northwest Coast. Measurements of sulfate and nitrate scavenging coefficients by clouds are also presented.

Sediment transport and trapping in marsh systems: Implications of tidal flux studies

Although the concept that marshes act as major sediment sinks may be accurate when viewing them over the last few millennia, tidal transport studies suggest considerable variability with most marshes presently exporting material on an annual basis. High-salinity marshes along the mid-Atlantic coast of the United States appear to be losing 1–2 kg m −2 yr −1 while submerged upland marshes on the Delmarva Peninsula are eroding at rates of up to 14 kg m −2 yr −1. By comparison, at least one deltaic marsh on the Dutch coast along with several estuarine marshes appear to be accumulating sediment. In order to assess the trapping ability of marshes in large estuaries, we constructed a sediment budget for Chesapeake Bay which included a variety of wetland types. Calculations indicate that estuarine marshes trap 5–11% of the annual Chesapeake Bay sediment input, or about one half that previously estimated. It appears that most sedimentation in estuaries, and perhaps other coastal systems, occurs in subtidal flats below the limit of emergent marsh vegetation. As mud flats become vegetated and estuarine infilling proceeds, there may be a tendency for tidal currents to become ebb-dominated which promotes a net export of particulates. The extent to which major storm events are capable of returning enough material to balance the long-term accretionary budget of tidal marshes and keep them abreast of rising sea level is open to question. Differences in tidal dynamics, seasonal changes in sea levels and higher temperatures may help explain why, in the U.S., southern marshes are more susceptible to export and eventual erosion than northern marshes. We hypothesize that another factor, the recent reductions of terrigenous sediment inputs from the southern river systems of the U.S., may also be critical. Sediment starvation may have led to undernourishment of wetland systems of the coastal zone over the last half century which may be reflected in the net export measured in the tidal marshes in this region. Furthermore, we postulate that changes in sediment inputs are more important than eustatic sea level rise in causing the past losses of marshes which are now undergoing mass erosion. Thus, future wetland survival will depend as much as particulate inputs to the coastal zone as on the prospects of a global rise in sea level, and more efforts should be made to quantify the sediment budgets of tidal marshes.

The Genesis of Atlantic Lows Experiment: The Planetary-Boundary-Layer Subprogram of GALE

Abstract The Genesis of Atlantic Lows Experiment (GALE), focused an intensive data-gathering effort along the mid-Atlantic coast of the United States from 15 January through 15 March 1986. Here, the general objectives and experimental layout are described with special emphasis on the planetary-boundary-layer (PBL) component of GALE. Instrumentation is described for buoys, ships, research aircraft, and towers. The networks of the cross-chain long range aid to navigation (LORAN) atmospheric sounding system (CLASS) and the portable automated mesonet (PAM II) are described and their impact on the operation of GALE is outlined. Special use of dual-Doppler radar to obtain detailed wind measurements in the PBL is discussed. Preliminary analyses for a selected observational period are given. Detailed observations of the offshore coastal front reveal direct mesoscale circulations imbedded in the frontal zone. Later in the period, during an intense cold-air outbreak, sensible-heat and latent-heat fluxes over the co...