Origin and Fate of the Chukchi Slope Current Using a Numerical Model and In‐situ Data

A variety of current profile data sources are compared for a deepwater site offshore Brazil. These data were gathered for consideration as part of the Worldwide Approximations of Current Profiles (WACUP) Joint Industry Project, described separately in OMAE2012-83348. The primary source of data for current profile characterisation is site specific full water column measurement. Sufficiently high vertical and temporal resolutions are required to capture the dominant oceanographic processes. Such in-situ data are generally expensive and time consuming to collect, so there is an increasing tendency for numerical model current data to be considered for engineering applications. In addition to being relatively inexpensive and quick to obtain, model data are also typically of much longer duration. This potentially allows inter-annual variability and rare extreme events to be captured. However, the accuracy and reliability of numerical model data remains questionable, or unproven, in many deepwater development regions. This paper explores the suitability of such models to represent a deepwater site offshore Brazil, in relation to the key oceanographic processes revealed within the in-situ data.

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Deepwater Current Profile Data Sources for Riser Engineering Offshore West Africa

Volume 5: Ocean Engineering ◽

10.1115/omae2013-10540 ◽

2013 ◽

Cited By ~ 1

Author(s):

Gus Jeans ◽

Liam Harrington-Missin ◽

Mark Calverley ◽

Christophe Maisondieu ◽

Cyril Frelin ◽

...

Keyword(s):

Numerical Model ◽

West Africa ◽

Primary Source ◽

Current Data ◽

Model Data ◽

Current Profile ◽

Field Development ◽

In Situ Data ◽

Reliable Quantification

Reliable quantification of current profiles is required for safe and cost effective offshore exploration and field development. The current regime offshore West Africa is often considered benign, compared to some regions of oil and gas activity, but still presents challenges to reliable quantification. A key challenge to all offshore developments is acquisition of appropriate data. The primary source of data for riser design is site specific full water column measurement. Such in-situ data are generally expensive and time consuming to collect, so there is an increasing tendency for numerical model current data to be considered. Model data are often relatively quick and inexpensive to obtain, with the added benefit of a much longer duration, potentially allowing inter-annual variability and extreme events to be captured. However, the accuracy and reliability of numerical model data remains questionable, or unproven, in many deepwater development regions. This paper explores the suitability of such models to represent a deepwater site offshore West Africa, in relation to the key oceanographic processes revealed within the in-situ data.

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Current Profile Data Sources for Engineering Design West of Shetlands

Volume 8B: Ocean Engineering ◽

10.1115/omae2014-24114 ◽

2014 ◽

Cited By ~ 1

Author(s):

Gus Jeans ◽

Joe Fox ◽

Claire Channelliere

Keyword(s):

Numerical Model ◽

Engineering Design ◽

Current Data ◽

Data Sources ◽

Model Data ◽

Current Profile ◽

Profile Data ◽

Field Development ◽

In Situ Data

Current profile data sources considered for derivation of engineering design criteria West of Shetland are described. The region is impacted by a variety of oceanographic processes that combine to produce a complex current regime. Reliable quantification of the resulting current profiles is required for safe and cost effective offshore exploration and field development. A key challenge to all offshore developments is acquisition of appropriate data. Site specific measurement remains the primary current profile data source for engineering applications, with full water column coverage at sufficient resolution required for riser design. Such in-situ data are generally expensive and time consuming to collect, so there is an increasing tendency for numerical model current data to be considered. Model data are often relatively quick and inexpensive to obtain, with the added benefit of a much longer duration, potentially allowing inter-annual variability and extreme events to be captured. However, the accuracy and reliability of numerical model data remains questionable, or unproven, in many deepwater development regions. This paper describes a recent study in which in-situ data remained the primary source for derivation of current profile criteria for engineering design. Short duration proprietary data were supplemented by additional public domain data from nearby sites in a regional synthesis, with critical results. The performance and benefits of readily available model data are also considered.

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STORM ICE OIL WIND WAVE WATCH SYSTEM (SIOWS): WEB GIS APPLICATION FOR MONITORING THE ARCTIC

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b93852689d4.28131112 ◽

2017 ◽

Author(s):

Alexander Myasoedov ◽

Sergey Azarov ◽

Ekaterina Balashova ◽

...

Keyword(s):

Satellite Data ◽

Wind Wave ◽

Arctic Region ◽

Web Gis ◽

The Arctic ◽

Flexible Tool ◽

In Situ Data ◽

Current State ◽

Watch System

Working with satellite data, has long been an issue for users which has often prevented from a wider use of these data because of Volume, Access, Format and Data Combination. The purpose of the Storm Ice Oil Wind Wave Watch System (SIOWS) developed at Satellite Oceanography Laboratory (SOLab) is to solve the main issues encountered with satellite data and to provide users with a fast and flexible tool to select and extract data within massive archives that match exactly its needs or interest improving the efficiency of the monitoring system of geophysical conditions in the Arctic. SIOWS - is a Web GIS, designed to display various satellite, model and in situ data, it uses developed at SOLab storing, processing and visualization technologies for operational and archived data. It allows synergistic analysis of both historical data and monitoring of the current state and dynamics of the "ocean-atmosphere-cryosphere" system in the Arctic region, as well as Arctic system forecasting based on thermodynamic models with satellite data assimilation.

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Critical Dynamics of Defects and Mechanisms of Damage-Failure Transitions in Fatigue

Materials ◽

10.3390/ma14102554 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2554

Author(s):

Oleg Naimark ◽

Vladimir Oborin ◽

Mikhail Bannikov ◽

Dmitry Ledon

Keyword(s):

Fatigue Damage ◽

Kinetic Equations ◽

Experimental Methodology ◽

Preliminary Deformation ◽

Scaling Properties ◽

In Situ Data ◽

Number Of Cycles ◽

Fish Eye ◽

Very High

An experimental methodology was developed for estimating a very high cycle fatigue (VHCF) life of the aluminum alloy AMG-6 subjected to preliminary deformation. The analysis of fatigue damage staging is based on the measurement of elastic modulus decrement according to “in situ” data of nonlinear dynamics of free-end specimen vibrations at the VHCF test. The correlation of fatigue damage staging and fracture surface morphology was studied to establish the scaling properties and kinetic equations for damage localization, “fish-eye” nucleation, and transition to the Paris crack kinetics. These equations, based on empirical parameters related to the structure of the material, allows us to estimate the number of cycles for the nucleation and advance of fatigue crack.

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Measuring and inferring the ice thickness distribution of four glaciers in the Tien Shan, Kyrgyzstan

Journal of Glaciology ◽

10.1017/jog.2020.104 ◽

2020 ◽

pp. 1-18

Author(s):

Lander Van Tricht ◽

Philippe Huybrechts ◽

Jonas Van Breedam ◽

Johannes J. Fürst ◽

Oleg Rybak ◽

...

Keyword(s):

Cross Validation ◽

Thickness Distribution ◽

Tien Shan ◽

Ice Thickness ◽

Ice Volume ◽

In Situ Data ◽

Radio Echo Sounding ◽

Thickness Measurements ◽

Tien Shan Mountains

Abstract Glaciers in the Tien Shan mountains contribute considerably to the fresh water used for irrigation, households and energy supply in the dry lowland areas of Kyrgyzstan and its neighbouring countries. To date, reconstructions of the current ice volume and ice thickness distribution remain scarce, and accurate data are largely lacking at the local scale. Here, we present a detailed ice thickness distribution of Ashu-Tor, Bordu, Golubin and Kara-Batkak glaciers derived from radio-echo sounding measurements and modelling. All the ice thickness measurements are used to calibrate three individual models to estimate the ice thickness in inaccessible areas. A cross-validation between modelled and measured ice thickness for a subset of the data is performed to attribute a weight to every model and to assemble a final composite ice thickness distribution for every glacier. Results reveal the thickest ice on Ashu-Tor glacier with values up to 201 ± 12 m. The ice thickness measurements and distributions are also compared with estimates composed without the use of in situ data. These estimates approach the total ice volume well, but local ice thicknesses vary substantially.

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Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽

10.3390/buildings11070276 ◽

2021 ◽

Vol 11 (7) ◽

pp. 276

Author(s):

Nisar Ali Khan ◽

Giorgio Monti ◽

Camillo Nuti ◽

Marco Vailati

Keyword(s):

Numerical Model ◽

Construction Materials ◽

Building Codes ◽

Construction Technique ◽

Infill Walls ◽

Mortar Strength ◽

Materials Used ◽

Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

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Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-9435-2016 ◽

2016 ◽

Vol 16 (14) ◽

pp. 9435-9455 ◽

Cited By ~ 8

Author(s):

Matthew J. Alvarado ◽

Chantelle R. Lonsdale ◽

Helen L. Macintyre ◽

Huisheng Bian ◽

Mian Chin ◽

...

Keyword(s):

Optical Properties ◽

Size Distribution ◽

Aerosol Size Distribution ◽

Visible Radiation ◽

Submicron Aerosol ◽

In Situ Data ◽

Aerosol Absorption ◽

Aerosol Scattering ◽

The Impact

Abstract. Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction throughout the aerosol size distribution. Using a core-shell mixing rule in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for modeling the time-varying mixing states of aerosols in future versions of ASP.

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