25 research outputs found
Extratropical storm inundation testbed: Intermodel comparisons in Scituate, Massachusetts: EXTRATROPICAL STORM INUNDATION TESTBED
The Integrated Ocean Observing System Super-regional Coastal Modeling Testbed had one objective to evaluate the capabilities of three unstructured-grid fully current-wave coupled ocean models (ADCIRC/SWAN, FVCOM/SWAVE, SELFE/WWM) to simulate extratropical storm-induced inundation in the US northeast coastal region. Scituate Harbor (MA) was chosen as the extratropical storm testbed site, and model simulations were made for the 24-27 May 2005 and 17-20 April 2007 (Patriot's Day Storm) nor'easters. For the same unstructured mesh, meteorological forcing, and initial/boundary conditions, intermodel comparisons were made for tidal elevation, surface waves, sea surface elevation, coastal inundation, currents, and volume transport. All three models showed similar accuracy in tidal simulation and consistency in dynamic responses to storm winds in experiments conducted without and with wave-current interaction. The three models also showed that wave-current interaction could (1) change the current direction from the along-shelf direction to the onshore direction over the northern shelf, enlarging the onshore water transport and (2) intensify an anticyclonic eddy in the harbor entrance and a cyclonic eddy in the harbor interior, which could increase the water transport toward the northern peninsula and the southern end and thus enhance flooding in those areas. The testbed intermodel comparisons suggest that major differences in the performance of the three models were caused primarily by (1) the inclusion of wave-current interaction, due to the different discrete algorithms used to solve the three wave models and compute water-current interaction, (2) the criterions used for the wet-dry point treatment of the flooding/drying process simulation, and (3) bottom friction parameterizations
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Wetland‐estuarine‐shelf interactions in the Plum Island Sound and Merrimack River in the Massachusetts coast
Wetland‐estuarine‐shelf interaction processes in the Plum Island Sound and Merrimack River system in the Massachusetts coast are examined using the high‐resolution
unstructured grid, finite volume, primitive equations, coastal ocean model. The
computational domain covers the estuarine and entire intertidal area with a horizontal
resolution of 10–200 m. Driven by five tidal constituents forcing at the open boundary on
the inner shelf of the eastern coast of the Gulf of Maine, the model has successfully
simulated the 3‐D flooding/drying process, temporal variability, and spatial distribution of
salinity as well as the water exchange flux through the water passage between the Plum
Island Sound and Merrimack River. The model predicts a complex recirculation loop
around the Merrimack River, shelf, and Plum Island Sound. During the ebb tide, salt water
in the Plum Island Sound is injected into the Merrimack River, while during flood tide, a
significant amount of the freshwater in the Merrimack River is forced into Plum Island
Sound. This water exchange varies with the magnitude of freshwater discharge and wind
conditions, with a maximum contribution of ∼30%–40% variability in salinity over tidal
cycles in the mouth of the Merrimack River. Nonlinear tidal rectification results in a
complex clockwise residual recirculation loop around the Merrimack River, shelf, and
Plum Island Sound. The net water flux from Plum Island Sound to the Merrimack River
varies with the interaction between tide, river discharge, and wind forcing. This interaction,
in turn, affects the salt transport from this system to the shelf. Since the resulting water
transport into the shelf significantly varies with the variability of the wind, models that fail
to resolve this complex estuarine and shelf system could either overestimate or
underestimate the salt content over the shelf.KEYWORDS: Wetland-estuarine-shelf interactions, Merrimack River, Massachusetts, Plum Island Sound, Massachusett
Research on the Application of Cross-Specialty Education and Situational Simulation Teaching in Operation Nursing Practice Teaching
Objective To examine the practical effect of inter-professional education and situational simulation teaching implemented in surgical nursing practice teaching. Methods On the whole, 100 undergraduate nursing students in the operating room of the hospital of the authors from May 2019 to August 2020 were selected. These students fell to two groups with the random number table method. The control received the regular teaching, and the research group were given the interprofessional education and context. The Simulation teaching was conducted to compare the theoretical knowledge, skill level, various abilities of the two groups of students, as well as the satisfaction of the operating room doctors to the nursing cooperation of the interns. Results The research group achieved higher theoretical knowledge and a higher skill level than the control (p < 0.05); the various abilities of the research group were higher than those of the control (p < 0.05); the operating room doctors of the research group were more satisfied with the nursing cooperation of interns, as compared with those of the control (p < 0.05). Conclusion In the surgical nursing practice teaching, the inter-professional education and the situational simulation teaching have significant effects and are worth clinical applications
Extratropical storm inundation testbed : intermodel comparisons in Scituate, Massachusetts
Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 118 (2013): 5054–5073, doi:10.1002/jgrc.20397.The Integrated Ocean Observing System Super-regional Coastal Modeling Testbed had one objective to evaluate the capabilities of three unstructured-grid fully current-wave coupled ocean models (ADCIRC/SWAN, FVCOM/SWAVE, SELFE/WWM) to simulate extratropical storm-induced inundation in the US northeast coastal region. Scituate Harbor (MA) was chosen as the extratropical storm testbed site, and model simulations were made for the 24–27 May 2005 and 17–20 April 2007 (“Patriot's Day Storm”) nor'easters. For the same unstructured mesh, meteorological forcing, and initial/boundary conditions, intermodel comparisons were made for tidal elevation, surface waves, sea surface elevation, coastal inundation, currents, and volume transport. All three models showed similar accuracy in tidal simulation and consistency in dynamic responses to storm winds in experiments conducted without and with wave-current interaction. The three models also showed that wave-current interaction could (1) change the current direction from the along-shelf direction to the onshore direction over the northern shelf, enlarging the onshore water transport and (2) intensify an anticyclonic eddy in the harbor entrance and a cyclonic eddy in the harbor interior, which could increase the water transport toward the northern peninsula and the southern end and thus enhance flooding in those areas. The testbed intermodel comparisons suggest that major differences in the performance of the three models were caused primarily by (1) the inclusion of wave-current interaction, due to the different discrete algorithms used to solve the three wave models and compute water-current interaction, (2) the criterions used for the wet-dry point treatment of the flooding/drying process simulation, and (3) bottom friction parameterizations.This project was supported by NOAA
via the U.S.IOOS Office (award: NA10NOS0120063 and
NA11NOS0120141) and was managed by the Southeastern Universities
Research Association. The Scituate FVCOM setup was supported by the
NOAA-funded IOOS NERACOOS program for NECOFS and the MIT
Sea Grant College Program through grant 2012-R/RC-127.2014-04-0
Investigation and assessment of ecological water resources in the salt marsh area of a salt lake: A case study of West Taijinar Lake in the Qaidam Basin, China.
The water ecology of salt marshes plays a crucial role in climate regulation, industrial production, and flood control. Due to a poor understanding of water ecology and the extensive mining of salt resources, concerns are mounting about declining groundwater levels, shrinking salt marshes, and other problems associated with the simple yet extremely fragile water ecosystem of salt marshes in arid salt lake areas. This study assessed the ecological status of water resources in the downstream salt marsh area of West Taijinar Lake in the Qaidam Basin, China (2010-2018). Using data from a field investigation, the water ecosystem was divided into an ecological pressure subsystem, an environmental quality subsystem, and a socio-economic subsystem according to an analytic hierarchy process. Each subsystem was quantitatively assessed using the ecological footprint model, the single-factor index, and available data for the salt marsh area. The results showed that water resources were always in a surplus state during the study period, whose development and utilization had a safe status. Surface water had low plankton diversity with no evidence of eutrophication, but its Cl- and SO42- concentrations were too high for direct industrial water uses. Groundwater quality was classified into class V because of high salt concentrations, which could be considered for industrial use given the demand of industrial production. The socio-economic efficiency of water resources was high, as distinguished by decreased water consumption per 10,000 yuan GDP and excellent flood resistance. In conclusion, the ecological status of water resources was deemed good in the study area and this could help sustain regional development. However, since the water ecology in this area is mainly controlled by annual precipitation, it would be challenging to deal with the uneven distribution of precipitation and flood events and to make full use of them for groundwater recharge. This study provides insight into the impact of salt lake resource exploration on water ecology, and the results can be useful for the rational utilization of water resources in salt marshes in other arid areas
Investigating the Shear Strength of Granitic Gneiss Residual Soil Based on Response Surface Methodology
The shear strength of granitic gneiss residual soil (GGRS) determines the stability of colluvial landslides in the Huanggang area, China. It depends on several parameters that represent its structure and state as well as their interactions, and therefore requires accurate assessment. For an effective evaluation of shear strength parameters of GGRS based on these factors and their interactions, three parameters, namely, moisture content, bulk density, and fractal dimension of grain size, were selected as influencing factors in this study based on a thorough investigation of the survey data and physical property tests of landslides in the study area. The individual effects and interaction of the factors were then incorporated by implementing a series of direct shear tests employing the response surface methodology (RSM) into the regression model of the shear parameters. The results indicate that the factors affecting shear parameters in the order of greater to lower are bulk density, moisture content, and fractal dimension, and their interactions are insignificant. The proposed model was validated by applying it to soil specimens from other landslide sites with the same parent bedrock, showing the validity of the strength regression model. This study demonstrates that RSM can be applied for parameter estimation of soils and provide reliable performance, and is also significant for conducting landslide investigation, evaluation, and regional risk assessment
Identification of persistent benthic assemblages in areas with different temperature variability patterns through broad-scale mapping.
Ecosystem-based management is a place-based approach that considers the relationships between system parts. Due to the complexity of ecosystems in the marine environment it is often difficult to define these relationships in space and time. Maps illustrate spatial concepts. Here we promote ecosystem-based spatial thinking by layering datasets from a larger project that mapped benthic fauna, substrate characteristics, and oceanic conditions on monthly, annual and decadal time scales along the U.S. continental shelf. By combining maps of persistent benthic megafauna and bottom temperature variability over approximately 90,000 km2, we identified wide spread benthic animal assemblages and regional disparity in temperature variability. From a broad-scale perspective the locations of the assemblage appear to be related to sea scallop population dynamics and indicate potential regional differences in climate change resiliency. These findings offer information on a scale that correlates with marine spatial planning, and could be used as a starting point for further investigation. To spur additional analysis and facilitate their linkage to other datasets, these datasets are available through public, online data portals. Overall, this study demonstrates how the growth of maps from single to multiple elements can help promote and facilitate the multifactor, ecosystem-based thinking needed to support regional ocean planning
Mechanism studies of seasonal variability of dissolved oxygen in Mass Bay: A multi-scale FVCOM/UG-RCA application
Long-term (1992-2010) water quality monitoring records reveal that the dissolved oxygen (DO) concentration in Mass Bay exhibits a well-defined seasonal cycle, highest in March-April and lowest in October. This pattern persists in all years with insignificant interannual variability. A multi-domain-nested coupled physical-biogeochemical model was developed and applied to simulate the DO field over the 16-year period 1995-2010. The model-computed DO and nitrogen concentrations were in good agreement with observations. An EOF analysis of the modeled DO field indicates that DO in Mass Bay features both well-defined seasonal and spatial modes. The magnitude and phase of the DO seasonal cycle vary more significantly in the southern bay than in the northern bay. Horizontal advection, which is connected to the western Gulf of Maine coastal currents, plays a dominant role in the DO variability in the northern bay. The southern bay features a well-defined local retention mechanism with a longer residence time. In this region, the DO variation is controlled predominantly by local biogeochemical processes. Since the photosynthetic minus respiration production of DO is always balanced to a large degree by the oxidation of organic matters, reaeration becomes a major driver for the seasonal cycle of DO. © 2013 Elsevier B.V