In situ hydrodynamic and morphodynamic measurements during extreme storm events

Post-Hurricane Michael damage assessment using ADCIRC storm surge hindcast, image classification, and LiDAR

Shore & Beach ◽

10.34237/1008741 ◽

2019 ◽

pp. 3-14 ◽

Cited By ~ 1

Author(s):

Joshua Davis ◽

Diana Mitsova ◽

Tynon Briggs ◽

Tiffany Briggs

Keyword(s):

Wave Energy ◽

Field Studies ◽

Feedback Mechanism ◽

Water Velocity ◽

Airborne Lidar ◽

Storm Events ◽

Magnetic Current ◽

Coastal Mapping ◽

Electro Magnetic

Wave forcing from hurricanes, nor’easters, and energetic storms can cause erosion of the berm and beach face resulting in increased vulnerability of dunes and coastal infrastructure. LIDAR or other surveying techniques have quantified post-event morphology, but there is a lack of in situ hydrodynamic and morphodynamic measurements during extreme storm events. Two field studies were conducted in March 2018 and April 2019 at Bethany Beach, Delaware, where in situ hydrodynamic and morphodynamic measurements were made during a nor’easter (Nor’easter Riley) and an energetic storm (Easter Eve Storm). An array of sensors to measure water velocity, water depth, water elevation and bed elevation were mounted to scaffold pipes and deployed in a single cross-shore transect. Water velocity was measured using an electro-magnetic current meter while water and bed elevations were measured using an acoustic distance meter along with an algorithm to differentiate between the water and bed during swash processes. GPS profiles of the beach face were measured during every day-time low tide throughout the storm events. Both accretion and erosion were measured at different cross-shore positions and at different times during the storm events. Morphodynamic change along the back-beach was found to be related to berm erosion, suggesting an important morphologic feedback mechanism. Accumulated wave energy and wave energy flux per unit area between Nor’easter Riley and a recent mid-Atlantic hurricane (Hurricane Dorian) were calculated and compared. Coastal Observations: JALBTCX/NCMP emergency-response airborne Lidar coastal mapping & quick response data products for 2016/2017/2018 hurricane impact assessments

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Coliform transport in a pristine reservoir: modeling and field studies

Water Science & Technology ◽

10.2166/wst.1998.0124 ◽

1998 ◽

Vol 37 (2) ◽

pp. 137-144 ◽

Cited By ~ 11

Author(s):

Elisa Garvey ◽

John E. Tobiason ◽

Michael Hayes ◽

Evelyn Wolfram ◽

David A. Reckhow ◽

...

Keyword(s):

Model Development ◽

Fate And Transport ◽

Field Studies ◽

Meteorological Conditions ◽

Reservoir Modeling ◽

Vertical Circulation ◽

Quality Model ◽

Circulation Patterns ◽

In Situ Experiments

This paper reports on field studies and model development aimed at understanding coliform fate and transport in the Quabbin Reservoir, an oligotrophic drinking water supply reservoir. An investigation of reservoir currents suggested the importance of wind driven phenomena, and that both lateral and vertical circulation patterns exist. In-situ experiments of coliform decay suggested dependence on light intensity and yielded an appropriate decay coefficient to be used in CE-QUAL-W2, a two-dimensional hydrodynamic and water quality model. Modeling confirmed the sensitivity of reservoir outlet concentration to vertical variability within the reservoir, meteorological conditions, and location of coliform source.

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Real-life Field Studies of the NOx Removing Properties of Photocatalytic Surfaces in Roskilde and Copenhagen Airport, Denmark

Journal of Photocatalysis ◽

10.2174/2665976x01999200811155905 ◽

2020 ◽

Vol 01 ◽

Author(s):

Henrik Jensen ◽

Pernille D. Pedersen

Keyword(s):

Air Quality ◽

High Stability ◽

Reference Site ◽

Real Life ◽

Field Studies ◽

The Real ◽

Before And After ◽

Parking Lot ◽

Photocatalytic Concrete

Aims: To evaluate the real-life effect of photocatalytic surfaces on the air quality at two test-sites in Denmark. Background: Poor air quality is today one of the largest environmental issues, due to the adverse effects on human health associated with high levels of air pollution, including respiratory issues, cardiovascular disease (CVD), and lung cancer. NOx removal by TiO2 based photocatalysis is a tool to improve air quality locally in areas where people are exposed. Methods: Two test sites were constructed in Roskilde and Copenhage airport. In Roskilde, the existing asphalt at two parking lots was treated with TiO2 containing liquid and an in-situ ISO 22197-1 test setup was developed to enable in-situ evaluation of the activity of the asphalt. In CPH airport, photocatalytic concrete tiles were installed at the "kiss and fly" parking lot, and NOx levels were continuously monitored in 0.5 m by CLD at the active site and a comparable reference site before and after installation for a period of 2 years. Results: The Roskilde showed high stability of the photocatalytic coating with the activity being largely unchanged over a period of 2 years. The CPH airport study showed that the average NOx levels were decreased by 12 % comparing the before and after NOx concentrations at the active and reference site. Conclusion: The joined results of the two Danish demonstration projects illustrate a high stability of the photocatalytic coating as well as a high potential for improvements of the real-life air quality in polluted areas.

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Observations of Tidal Flat Sedimentation within a Native and an Exotic Spartina Species

Water ◽

10.3390/w13111566 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1566

Author(s):

Barbara Proença ◽

Florian Ganthy ◽

Richard Michalet ◽

Aldo Sottolichio

Keyword(s):

Single Point ◽

Field Measurements ◽

Species Variation ◽

Storm Events ◽

Level Variation ◽

Wave Forcing ◽

Bed Elevation ◽

Sediment Stabilization ◽

Consistent Response

Field measurements of bed elevation and related wave events were performed within a tidal marsh, on two cordgrass species, Spartina anglica (exotic) and Spartina maritima (native), in the Bay of Arcachon (SW France). Bed- and water-level time series were used to infer on the sediment behavior patterns from short to long term. A consistent response was found between the bed-level variation and the wave forcing, with erosion occurring during storms and accretion during low energy periods. Such behavior was observed within the two species, but the magnitude of bed-level variation was higher within the native than the exotic Spartina. These differences, in the order of millimeters, were explained by the opposite allocation of biomass of the two species. On the long term, the sedimentation/erosion patterns were dominated by episodic storm events. A general sediment deficit was observed on the site, suggested by an overall bed-level decrease registered within both species. However, further verification of within species variation needs to be considered when drawing conclusions. Despite possible qualitative limitations of the experimental design, due to single point survey, this work provides original and considerable field data to the understanding the different species ability to influence bed sediment stabilization and their potential to build marsh from the mudflat pioneer stage. Such information is valuable for coastal management in the context of global change.

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Wave Breaking Dissipation in a Young Wind Sea

Journal of Physical Oceanography ◽

10.1175/jpo-d-12-0237.1 ◽

2014 ◽

Vol 44 (1) ◽

pp. 104-127 ◽

Cited By ~ 31

Author(s):

Michael Schwendeman ◽

Jim Thomson ◽

Johannes R. Gemmrich

Keyword(s):

Wind Waves ◽

Phase Speed ◽

Field Studies ◽

Turbulent Energy ◽

Strength Parameter ◽

Video Recordings ◽

Sonar System ◽

Wind Sea ◽

Equilibrium Range

Abstract Coupled in situ and remote sensing measurements of young, strongly forced wind waves are applied to assess the role of breaking in an evolving wave field. In situ measurements of turbulent energy dissipation from wave-following Surface Wave Instrument Float with Tracking (SWIFT) drifters and a tethered acoustic Doppler sonar system are consistent with wave evolution and wind input (as estimated using the radiative transfer equation). The Phillips breaking crest distribution Λ(c) is calculated using stabilized shipboard video recordings and the Fourier-based method of Thomson and Jessup, with minor modifications. The resulting Λ(c) are unimodal distributions centered around half of the phase speed of the dominant waves, consistent with several recent studies. Breaking rates from Λ(c) increase with slope, similar to in situ dissipation. However, comparison of the breaking rate estimates from the shipboard video recordings with the SWIFT video recordings show that the breaking rate is likely underestimated in the shipboard video when wave conditions are calmer and breaking crests are small. The breaking strength parameter b is calculated by comparison of the fifth moment of Λ(c) with the measured dissipation rates. Neglecting recordings with inconsistent breaking rates, the resulting b data do not display any clear trends and are in the range of other reported values. The Λ(c) distributions are compared with the Phillips equilibrium range prediction and previous laboratory and field studies, leading to the identification of several inconsistencies.

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Imaging the Plasmasphere and Topside Ionosphere during Geomagnetic Storms based on a Tomographic Algorithm

10.5194/egusphere-egu21-2512 ◽

2021 ◽

Author(s):

Fabricio Prol ◽

Mainul Hoque

Keyword(s):

Electron Density ◽

Space Weather ◽

Geomagnetic Storms ◽

Recovery Phase ◽

Topside Ionosphere ◽

Storm Events ◽

Density Distributions ◽

Defense Meteorological Satellite Program ◽

Meteorological Satellite

<p>In this study, TEC measurements from METOP (Meteorological Operational) satellites are used together with a tomographic algorithm to estimate electron density distributions during geomagnetic storm events. The proposed method is applied during four geomagnetic storms to check the tomographic capabilities for space weather monitoring. The developed method was capable to successfully capture and reconstruct well-known enhancement and decrease of electron density during the geomagnetic storms. The comparison with in-situ electron densities from DMSP (Defense Meteorological Satellite Program) satellites has shown an improvement around 11% and a better plasma description compared to the background. Our study also reveals that the plasmasphere TEC contribution to ground-based TEC may vary 10 to 60% during geomagnetic storms, and the contribution tends to reduce during the storm-recovery phase.</p>

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Sampling and Reconstructing User Experience

Mobile and Handheld Computing Solutions for Organizations and End-Users ◽

10.4018/978-1-4666-2785-7.ch013 ◽

2013 ◽

pp. 225-245

Author(s):

Panos Markopoulos ◽

Vassilis-Javed Khan

Keyword(s):

Experience Sampling ◽

Field Studies ◽

Reconstruction Method ◽

Working Parents ◽

Diary Method ◽

User Attitudes ◽

Communication Needs ◽

Sampling And Reconstruction

The Experience Sampling and Reconstruction Method (ESRM) is a research method suitable for user studies conducted in situ that is needed for the design and evaluation of ambient intelligence technologies. ESRM is a diary method supported by a distributed application, Reconexp, which runs on a mobile device and a website, enabling surveying user attitudes, experiences, and requirements in field studies. ESRM combines aspects of the Experience Sampling Method and the Day Reconstruction Method aiming to reduce data loss, improve data quality, and reduce burden put upon participants. The authors present a case study of using this method in the context of a study of communication needs of working parents with young children. Requirements for future developments of the tool and the method are discussed.

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General Overview of Autonomous Forward-Deployed Systems and Their Energy Needs

Marine Technology Society Journal ◽

10.4031/mtsj.51.4.3 ◽

2017 ◽

Vol 51 (4) ◽

pp. 6-11

Author(s):

Dallas J. Meggitt ◽

Michèle Bullock

Keyword(s):

Wave Energy ◽

Energy System ◽

Energy Requirements ◽

Practical Implementation ◽

Surveillance Systems ◽

Sensor Systems ◽

Solar Panels ◽

Remote Sensor ◽

Deployed Systems

AbstractForward-deployed and remote sensor systems all require persistent, autonomous, reliable in situ sources of energy. There are several different classes of forward-deployed systems, each of which typically has a different range of energy requirements. Some of these systems are buoys; others are bottom-laid. Several such systems are being developed for a variety of scientific and military applications, including, for example, (1) remote systems with a single or small number of sensors; (2) networked scientific sensor systems (Undersea Distributed Networks); (3) low-power, forward-deployed surveillance systems with many sensors; and (4) forward-deployed communications relay systems. Energy requirements for these systems depend on several factors, including overall energy requirements, mission duration, duty cycle, observability, and fixed or mobile system. Many previous and current forward-deployed systems have depended on batteries for energy, but batteries are limited in the amount of energy they can store unless they can be recharged or replaced. Some previous systems have used diesel, sometimes in combination with solar panels and battery backups, but solar panels degrade and lose efficiency with salt encrustation, corrosion, and bird excrement. Recent developments in reliable, scalable wave energy technology, together with relatively efficient energy storage technologies, offer the opportunity for application of these technologies for providing autonomous power to remote sensor systems. This paper describes several remote sensor systems, reviews and summarizes energy requirements for these systems, and provides in situ wave energy system concepts to meet these requirements. The paper focuses on wave energy as being closest to practical implementation of current renewable energy technologies.

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Identifying a possible stratification phenomenon in ionospheric F2 layer using the data observed by the DEMETER satellite: method and results

Annales Geophysicae ◽

10.5194/angeo-37-645-2019 ◽

2019 ◽

Vol 37 (4) ◽

pp. 645-655 ◽

Cited By ~ 1

Author(s):

Xiuying Wang ◽

Dehe Yang ◽

Dapeng Liu ◽

Wei Chu

Keyword(s):

Electron Density ◽

Langmuir Probe ◽

Geomagnetic Equator ◽

Density Data ◽

Demeter Satellite ◽

Summer Hemisphere ◽

Electro Magnetic ◽

First Time ◽

Different Altitudes

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe aboard the DEMETER (Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions) satellite at different altitudes, are analyzed, and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method is thus an effective one, which can also be used in similar studies of comparing fluctuated data.

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Nutrient concentration in sediments accumulated in pre-treatment basins of urban LID technologies

Water Science & Technology ◽

10.2166/wst.2019.033 ◽

2019 ◽

Vol 79 (5) ◽

pp. 1000-1006 ◽

Cited By ~ 2

Author(s):

F. K. F. Geronimo ◽

M. C. Maniquiz-Redillas ◽

J. S. Hong ◽

L. H. Kim

Keyword(s):

Low Impact Development ◽

Limiting Factor ◽

Particle Sizes ◽

Storm Events ◽

Nutrient Reduction ◽

Sediment Retention ◽

The Difference ◽

Pre Treatment ◽

Sand And Gravel

Abstract In this study, the contribution of pre-treatment basins of low impact development (LID) technologies to nutrient reduction performance was evaluated by understanding the distribution of nutrient in sediments accumulated in each system. The captured sediments were mostly silt to medium sand ranging from 9% to 92% of the sediments collected. Greater average N and P concentrations were found in silt particles amounting to 345 mg/kg and 696 mg/kg, respectively compared to sand and gravel. Although, N concentrations in accumulated sediments were found to be highly variable at different particle sizes (CV: 0.24 to 0.77) compared to P concentration (CV: 0.08 to 0.36) attributed to effective P treatment mechanism through deposition compared to complex nitrogen removal mechanisms. In addition, the difference between N and P concentrations of sediments collected in the pre-treatment basins of LID technologies and in-situ soil was attributed to the continuous pollutant input to the LID technologies during storm events. The study proved that pre-treatment basins of stormwater LID technologies reinforced the nutrient removal performances through sediment retention. The findings of this research may be used to design pre-treatment basins of LID technologies considering nutrients as a limiting factor.

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