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43-461: Narragansett Bay is a bay and estuary on the north side of Rhode Island Sound covering 147 square miles (380 km), 120.5 square miles (312 km) of which is in Rhode Island . The bay forms New England 's largest estuary, which functions as an expansive natural harbor and includes a small archipelago. Small parts of the bay extend into Massachusetts . There are more than 30 islands in

86-431: A recessional moraine , and exposed glaciolacustrine sediments. Modern bedforms consist of fields of transverse sand waves , barchanoid waves, giant scour depressions, and pockmarks) . Bedform asymmetry from multibeam bathymetric data indicate that net sediment transport is westward across the northern part of the study area near Fishers Island , and eastward across the southern part near Great Gull Island . Compared to

129-578: A static magnetic field is, by Ampère's law , proportional to the total current enclosed by the loop ∮ ∂ S B ⋅ d l = μ 0 ∬ S J ⋅ d S = μ 0 I enc . {\displaystyle \oint _{\partial S}\mathbf {B} \cdot \mathrm {d} \mathbf {l} =\mu _{0}\iint _{S}\mathbf {J} \cdot \mathrm {d} \mathbf {S} =\mu _{0}I_{\text{enc}}.} For systems with electric fields that change over time,

172-481: A large army". Dutch navigator Adriaen Block explored and mapped the bay in 1614, and nearby Block Island is named in his honor. The first permanent Colonial settlement was established in 1636 by Roger Williams , a former member of the Massachusetts Bay Colony . He was friends with Narragansett sachem Canonicus , who provided him with land on which to build Providence Plantations . Around

215-530: A line integral between any two points in the field is independent of the path taken. It also implies that the vector field can be expressed as the gradient of a scalar function, which is called a potential . Circulation can be related to curl of a vector field V and, more specifically, to vorticity if the field is a fluid velocity field, ω = ∇ × V . {\displaystyle {\boldsymbol {\omega }}=\nabla \times \mathbf {V} .} By Stokes' theorem ,

258-458: A new treatment that involves removal of nitrogen Narragansett Bay is the site of one of the world's longest-running plankton surveys, extending from 1957 through the present. Researchers at the University of Rhode Island ’s Graduate School of Oceanography collect samples weekly and the dataset contains 246 different species. Rhode Island Sound Geographically, Rhode Island Sound is

301-548: A population explosion within these waters. Mnemiopsis leidyi , commonly known as sea walnut comb jellies, and the Lion's mane jellyfish ( Cyanea capillata ), are disrupting habitats with their invasive behavior in the Rhode Island Sound waters. 41°26′00″N 71°12′58″W  /  41.43333°N 71.21611°W  / 41.43333; -71.21611 Circulation (fluid dynamics) In physics, circulation

344-404: Is a ria that consists of a series of flooded river valleys formed of dropped crustal blocks in a horst and graben system that is slowly subsiding between a shifting fault system. Providence is Rhode Island 's capital and largest city and sits at the northernmost arm of the bay. Many of Providence's suburbs are also on the bay, including East Providence , Warwick and Cranston . Newport

387-516: Is a vector representing the differential length of a small element of a defined curve, the contribution of that differential length to circulation is dΓ : d Γ = V ⋅ d l = | V | | d l | cos ⁡ θ . {\displaystyle \mathrm {d} \Gamma =\mathbf {V} \cdot \mathrm {d} \mathbf {l} =\left|\mathbf {V} \right|\left|\mathrm {d} \mathbf {l} \right|\cos \theta .} Here, θ

430-479: Is derived from the southern New England Algonquian word Naiaganset meaning "(people) of the small point of land". The watershed of Narragansett Bay has seven river sub-drainage basins , including the Taunton , Pawtuxet , and Blackstone Rivers , and they provide freshwater input at approximately 2.1 million U.S. gallons (7.9 × 10 ^  L) per day. River water inflow has a seasonal variability, with

473-471: Is highest in winter and lowest in summer, while CSOs increase dramatically following heavy rain. Water from these freshwater inputs mixes with sea water to form a salinity gradient ranging from 24 ppt at the mouth of the Providence River to 32 ppt at the mouth of the bay. Water temperatures range between -0.5 °C and 24 °C over the year. Salinity and temperature patterns measured throughout

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516-563: Is known as the Kutta–Joukowski theorem. This equation applies around airfoils, where the circulation is generated by airfoil action ; and around spinning objects experiencing the Magnus effect where the circulation is induced mechanically. In airfoil action, the magnitude of the circulation is determined by the Kutta condition . The circulation on every closed curve around the airfoil has

559-633: Is located at the south end of Aquidneck Island on the ocean, and is the home of the United States Naval War College , the Naval Undersea Warfare Center , and a major United States Navy training center. The city of Fall River, Massachusetts is located at the confluence of the Taunton River and Mount Hope Bay , which form the northeasternmost part of Narragansett Bay. The southwest side of

602-567: Is majorly impacted by large temporal fluctuations in the Rhode Island waters. In 2008, research conducted by the University of Rhode Island, Graduate School of Oceanography, shows that there is an increase in the abundance of a tunicate species, Didemnum . The species has been spotted in the Rhode Island Sound area since 2000, but has been rapidly increasing in numbers ever since. Two certain species of jellyfish are currently having

645-451: Is the line integral of a vector field around a closed curve. In fluid dynamics , the field is the fluid velocity field . In electrodynamics , it can be the electric or the magnetic field. Circulation was first used independently by Frederick Lanchester , Martin Kutta and Nikolay Zhukovsky . It is usually denoted Γ ( Greek uppercase gamma ). If V is a vector field and d l

688-450: Is the angle between the vectors V and d l . The circulation Γ of a vector field V around a closed curve C is the line integral : Γ = ∮ C V ⋅ d l . {\displaystyle \Gamma =\oint _{C}\mathbf {V} \cdot \mathrm {d} \mathbf {l} .} In a conservative vector field this integral evaluates to zero for every closed curve. That means that

731-632: The flux of curl or vorticity vectors through a surface S is equal to the circulation around its perimeter, Γ = ∮ ∂ S V ⋅ d l = ∬ S ∇ × V ⋅ d S = ∬ S ω ⋅ d S {\displaystyle \Gamma =\oint _{\partial S}\mathbf {V} \cdot \mathrm {d} \mathbf {l} =\iint _{S}\nabla \times \mathbf {V} \cdot \mathrm {d} \mathbf {S} =\iint _{S}{\boldsymbol {\omega }}\cdot \mathrm {d} \mathbf {S} } Here,

774-859: The Block Island Sound, the Rhode Island Sound is more prone to stratification since water currents are less dynamic in this area. Kelp population density is higher in the Rhode Island Sound compared to other temperate locations, particularly locations north of Rhode Island. However, even though annual kelp production is higher, the productivity of individual plants is lower due to lower biomass accumulation of fucoid algae. Studies conducted by Pilson, Asare, and Harlin between 1983 and 1985 illustrated that algal species such as Laminaria saccharina living in Rhode Island Sound waters have maximum nitrogen accumulation in their tissues, which directly correlates with maximum ambient inorganic nitrogen levels in tissues of other algal species as well. The cause of this

817-566: The North to South nutrient concentration gradient in the bay (24). Near the Providence River, biomass levels are highest in the summer and lowest in the winter. In the east and west passages there are peaks in the spring and fall. Annual blooms have shrunk over the last decade (2006 onward) as the amount of nitrogen (an important nutrient) supply to the bay has decreased by more than 50% due to wastewater treatment facilities switching to

860-438: The bay in his ship La Dauphine in 1524 after visiting New York Bay . Verrazzano called the bay Refugio , the "Refuge". It has several entrances, however, and historians can only speculate as to the exact route of his voyage and the location where he laid anchor, along with a corresponding uncertainty over which tribe made contact with him. Verrazzano reported that he found clearings and open forests suitable for travel "even by

903-525: The bay includes the seaside tourist towns of Narragansett and Wickford . Quonset Point , south of Warwick, gives its name to the Quonset hut . Tides in the watershed are measured at Providence, Fall River, Quonset Point, Conimicut Light , Prudence Island, and Newport. In shallow water, sound waves are used to measure water height by precisely measuring their travel time. In deeper water, tides are measured with pressure-sensing tide gauges that are placed on

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946-527: The bay indicate a range of mixed to stratified conditions and the amount of time it takes for the total volume of fresh water in the bay to be equaled by the fresh water input (flushing time) varies from 40 days to 10 days, depending on freshwater input. Dissolved oxygen levels in Narragansett Bay are seasonal with lower levels in the summer and higher levels in the winter. This is due to warmer temperatures and higher biological demand for oxygen in

989-532: The bay was probably in the early 16th century. At the time, the area surrounding the bay was inhabited by two different Indian tribes: the Narragansetts occupied the west side of the bay, and the Wampanoags lived on the east side, occupying the land east to Cape Cod . It is accepted by most historians that first contact by Europeans was made by Giovanni da Verrazzano , an Italian explorer who entered

1032-431: The bay. In the winter, winds come from the northwest, helping move water towards the bay's mouth; in the summer, they are out of the southwest and move water towards the head of the bay. Wind-driven waves of over 4.25 feet (1.30 m) also help mix surface waters. Density-driven forces are the third factor affecting circulation. Fresh water inflow comes from natural sources such as atmospheric precipitation and inflow from

1075-531: The bay; the three largest ones are Aquidneck Island , Conanicut Island , and Prudence Island . Bodies of water that are part of Narragansett Bay include the Sakonnet River , Mount Hope Bay , and the southern, tidal part of the Taunton River . The bay opens on Rhode Island Sound and the Atlantic Ocean; Block Island lies less than 20 miles (32 km) southwest of its opening. "Narragansett"

1118-829: The capture and burning of the British customs schooner Gaspee . The American victory contributed to the eventual start of the war at the Battles of Lexington and Concord in Massachusetts three years later. The event is celebrated in Pawtuxet Village as the Gaspee Days Celebration in June which includes burning the ship in effigy. Roger Williams and other early colonists named the islands Prudence , Patience , Hope , Despair , and Hog . To remember

1161-419: The circulation is mostly well-mixed; however, the Providence River does show some vertical stratification. Narragansett Bay circulation is made up of forces provided by the winds, tides, and changes in water density within the watershed. Its circulation is the result of the flow of fresh water at the head interacting with salt water at the point where the bay meets the open ocean. Residence time of water due to

1204-430: The circulation of Narragansett Bay is 10–40 days, with an average of 26 days. Tidal mixing is the dominant driver of circulation patterns in the bay, where currents can reach up to 2.5 feet per second. Non-tidal currents such as the flow of low salinity water at the surface out of the bay and high salinity deep water into the bay contribute to a current of about 0.33 feet per second. Winds also drive circulation patterns in

1247-404: The closed integration path ∂S is the boundary or perimeter of an open surface S , whose infinitesimal element normal d S = n dS is oriented according to the right-hand rule . Thus curl and vorticity are the circulation per unit area, taken around a local infinitesimal loop. In potential flow of a fluid with a region of vorticity , all closed curves that enclose the vorticity have

1290-417: The curl of the electric field is equal to the negative rate of change of the magnetic field, ∇ × E = − ∂ B ∂ t {\displaystyle \nabla \times \mathbf {E} =-{\frac {\partial \mathbf {B} }{\partial t}}} or that the circulation of the electric field around a loop is equal to the negative rate of change of

1333-419: The eastward extension of Block Island Sound . Northeast of Rhode Island Sound is Buzzards Bay . The Rhode Island Sound is approximately 2,500 km (970 sq mi) and has a maximum depth of 60 metres (200 ft). Average wave heights range from one to three metres (3.3 to 9.8 ft). Circulation and current strength are mostly impacted by the surrounding geology and not by wind strength. This causes

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1376-643: The highest flow in the spring and the minimum flow in early fall. The bay is a ria estuary (a drowned river valley) which is composed of the Sakonnet River valley, the East Passage river valley, and the West Passage river valley. The bathymetry varies greatly among the three passages, with the average depths of the East, West, and Sakonnet River passages being 121 feet (37 m), 33 feet (10 m), and 25 feet (7.6 m) respectively. Narragansett Bay

1419-658: The magnetic field flux through any surface spanned by the loop, by Stokes' theorem ∮ ∂ S E ⋅ d l = ∬ S ∇ × E ⋅ d S = − d d t ∫ S B ⋅ d S . {\displaystyle \oint _{\partial S}\mathbf {E} \cdot \mathrm {d} \mathbf {l} =\iint _{S}\nabla \times \mathbf {E} \cdot \mathrm {d} \mathbf {S} =-{\frac {\mathrm {d} }{\mathrm {d} t}}\int _{S}\mathbf {B} \cdot \mathrm {d} \mathbf {S} .} Circulation of

1462-400: The many rivers that feed into the watershed, and human-made sources such as water treatment plants. Fresh and saltwater mixing results in a salinity range in the bay of 24 parts per thousand (ppt) in the upper Providence River area to 32 ppt at the mouth of the bay. The bay's currents and circulation patterns greatly influence the sediment deposits within the region. The majority of

1505-648: The names, colonial school children often recited the poem: "Patience, Prudence, Hope, and Despair. And the little Hog over there." Narragansett Bay is divided by Conanicut Island into east and west passages. Its depth averages approximately 9.0 meters throughout the bay, but it is shallower in the west passage and deeper in the east. Narragansett Bay receives freshwater input from several sources, including rivers (approximately 80%), direct precipitation (13%), wastewater treatment facilities (9%), and unknown amounts from ground-water and combined sewer overflows (CSOs). The freshwater input varies greatly from season to season as it

1548-421: The ocean floor to measure water height. The bay's tides are semi-diurnal, meaning that the region experiences two high and low tides daily. The tides range in height from 3.6 feet (1.1 m) at the bay's mouth and 4.6 feet (1.4 m) at its head. Water depth varies about 4 feet (1.2 m) between high and low tide. The lunar, semi-diurnal M2 tide occurs at a period of 12.42 hours, with two tides occurring in

1591-772: The same time, the Dutch established a trading post approximately 12 miles (20 km) to the southwest which was under the authority of New Amsterdam in New York Bay. In 1643, Williams traveled to England and was granted a charter for the Colony of Rhode Island and Providence Plantations . The Gaspee Affair was an important naval event which moved the Thirteen Colonies toward the American Revolution . It occurred in Narragansett Bay in 1772 and involved

1634-613: The same value for circulation. In fluid dynamics, the lift per unit span (L') acting on a body in a two-dimensional flow field is directly proportional to the circulation, i.e. it can be expressed as the product of the circulation Γ about the body, the fluid density ρ {\displaystyle \rho } , and the speed of the body relative to the free-stream v ∞ {\displaystyle v_{\infty }} : L ′ = ρ v ∞ Γ {\displaystyle L'=\rho v_{\infty }\Gamma } This

1677-475: The same value, and is related to the lift generated by each unit length of span. Provided the closed curve encloses the airfoil, the choice of curve is arbitrary. Circulation is often used in computational fluid dynamics as an intermediate variable to calculate forces on an airfoil or other body. In electrodynamics, the Maxwell-Faraday law of induction can be stated in two equivalent forms: that

1720-555: The sea floor habitats in the Rhode Island Sound to be constantly changing. Studies conducted in 2006 by the Coastal Marine and Geology Program and the Long Island Sound Resource Center used digital terrain models to make topographical depictions of unknown glacial features and bedforms. Newfound glacial features include an ice-sculptured bedrock surface, residual stagnant-ice-contact deposits,

1763-466: The sediments within the bay are fine-grained material such as detritus, clay-silt, and sand-silt-clay. Scientists have been able to identify 11 types of sediment that range from coarse gravels to fine silts. the bay's currents deposit fine materials through the harbors of the lower and middle sections of the bay, and the coarse, heavy materials are deposited in the lower areas of the bay where the water velocities are higher. The first visit by Europeans to

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1806-571: The summer and the opposite in the winter. Narragansett Bay is also subject to periodic summer hypoxic events in the Northern half of the bay, nearing anoxic conditions in some parts. Phytoplankton forms the base of the food chain for many of the bay's marine animals. General trends in phytoplankton biomass across the bay are characterized by highest levels in the Providence River and lowest levels in Rhode Island Sound , correlating with

1849-487: The watershed every 24 hours and 50 minutes. The watershed's neap and spring tides occur every 14.8 days. In Narragansett bay, the tides show a distinct double-peak flood during high tide and single peak ebb during low tide. The movement of water within a system is its circulation . Estuaries are given a classification depending on the pattern of their circulations. The circulation classification can be well-mixed, partially mixed, salt wedge, or Fjord-type. For Narragansett,

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