ORCID Profile
0000-0002-9374-9357
Current Organisations
Universitas Padjadjaran
,
Bureau of Meteorology
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Physical Oceanography | Oceanography | Geophysical Fluid Dynamics | Climatology (excl. Climate Change Processes) | Numerical Computation | Climate Change Processes
ANZSRC Socio-Economic Objective (SEO)
Climate Change Models | Physical and Chemical Conditions of Water in Marine Environments | Climate Variability (excl. Social Impacts) | Marine Oceanic Processes (excl. climate related) |
Related Links
Publications
Dynamics and Predictability of El Niño–Southern Oscillation: An Australian Perspective on Progress and Challenges
Publisher: American Meteorological Society
Date: 03-2019
Abstract: El Niño and La Niña, the warm and cold phases of El Niño–Southern Oscillation (ENSO), cause significant year-to-year disruptions in global climate, including in the atmosphere, oceans, and cryosphere. Australia is one of the countries where its climate, including droughts and flooding rains, is highly sensitive to the temporal and spatial variations of ENSO. The dramatic impacts of ENSO on the environment, society, health, and economies worldwide make the application of reliable ENSO predictions a powerful way to manage risks and resources. An improved understanding of ENSO dynamics in a changing climate has the potential to lead to more accurate and reliable ENSO predictions by facilitating improved forecast systems. This motivated an Australian national workshop on ENSO dynamics and prediction that was held in Sydney, Australia, in November 2017. This workshop followed the aftermath of the 2015/16 extreme El Niño, which exhibited different characteristics to previous extreme El Niños and whose early evolution since 2014 was challenging to predict. This essay summarizes the collective workshop perspective on recent progress and challenges in understanding ENSO dynamics and predictability and improving forecast systems. While this essay discusses key issues from an Australian perspective, many of the same issues are important for other ENSO-affected countries and for the international ENSO research community.
The Modulation of Equatorial Turbulence by Tropical Instability Waves in a Regional Ocean Model
Publisher: American Meteorological Society
Date: 04-2015
Abstract: Small-scale turbulent mixing in the upper Equatorial Undercurrent (EUC) of the eastern Pacific cold tongue is a critical component of the SST budget that drives variations in SST on a range of time scales. Recent observations have shown that turbulent mixing within the EUC is modulated by tropical instability waves (TIWs). A regional ocean model is used to investigate the mechanisms through which large-scale TIW circulation modulates the small-scale shear, stratification, and shear-driven turbulence in the EUC. Eulerian analyses of time series taken from both the model and the Tropical Atmosphere Ocean (TAO) array suggest that increases in the zonal shear of the EUC drive increased mixing on the leading edge of the TIW warm phase. A Lagrangian vorticity analysis attributes this increased zonal shear to horizontal vortex stretching driven by the strain in the TIW horizontal velocity field acting on the existing EUC shear. To investigate the impact of horizontal vortex stretching on the turbulent heat flux averaged over a TIW period the effects of periodic TIW strain are included as forcing in a simple 1D mixing model of the EUC. Model runs with TIW forcing show turbulent heat fluxes up to 30% larger than runs without TIW forcing, with the magnitude of the increase being sensitive to the vertical mixing scheme used in the model. These results emphasize the importance of coupling between the large-scale circulation and small-scale turbulence in the equatorial regions, with implications for the SST budget of the equatorial Pacific.
Reviving the information veracity in healthcare supply chain with blockchain: a systematic review
Publisher: Informa UK Limited
Date: 09-04-2023
Supplementary material to "ACCESS-OM2: A Global Ocean-Sea Ice Model at Three Resolutions"
Publisher: Copernicus GmbH
Date: 30-04-2019
A research program for studying the impact of process representation on risk analysis
Publisher: Springer International Publishing
Date: 2013
Contribution of tropical instability waves to ENSO irregularity
Publisher: Springer Science and Business Media LLC
Date: 02-05-2018
Key Role of Diabatic Processes in Regulating Warm Water Volume Variability over ENSO Events
Publisher: American Meteorological Society
Date: 15-11-2020
Abstract: The equatorial Pacific warm water volume (WWV), defined as the volume of water warmer than 20°C near the equator, is a key predictor for El Niño–Southern Oscillation (ENSO), and yet much about the in idual processes that influence it remains unknown. In this study, we conduct idealized ENSO simulations forced with symmetric El Niño– and La Niña–associated atmospheric anomalies as well as a historical 1979–2016 hindcast simulation. We use the water mass transformation framework to examine the in idual contributions of diabatic and adiabatic processes to changes in WWV. We find that in both sets of simulations, El Niño’s discharge and La Niña’s recharge periods are initiated by diabatic fluxes of volume across the 20°C isotherm associated with changes in surface forcing and vertical mixing. Changes in adiabatic horizontal volume transport above 20°C between the equator and subtropical latitudes dominate at a later stage. While surface forcing and vertical mixing deplete WWV during El Niño, surface forcing during La Niña drives a large increase partially compensated for by a decrease driven by vertical mixing. On average, the ratio of diabatic to adiabatic contributions to changes in WWV during El Niño is about 40% to 60% during La Niña this ratio changes to 75% to 25%. The increased importance of the diabatic processes during La Niña, especially the surface heat fluxes, is linked to the shoaling of the 20°C isotherm in the eastern equatorial Pacific and is a major source of asymmetry between the two ENSO phases, even in the idealized simulations where the wind forcing and adiabatic fluxes are symmetric.
Off-Equatorial Deep-Cycle Turbulence Forced by Tropical Instability Waves in the Equatorial Pacific
Publisher: American Meteorological Society
Date: 05-2021
Abstract: The equatorial Pacific cold tongue is a site of large heat absorption by the ocean. This heat uptake is enhanced by a daily cycle of shear turbulence beneath the mixed layer—“deep-cycle turbulence”—that removes heat from the sea surface and deposits it in the upper flank of the Equatorial Undercurrent. Deep-cycle turbulence results when turbulence is triggered daily in sheared and stratified flow that is marginally stable (gradient Richardson number Ri ≈ 0.25). Deep-cycle turbulence has been observed on numerous occasions in the cold tongue at 0°, 140°W, and may be modulated by tropical instability waves (TIWs). Here we use a primitive equation regional simulation of the cold tongue to show that deep-cycle turbulence may also occur off the equator within TIW cold cusps where the flow is marginally stable. In the cold cusp, preexisting equatorial zonal shear u z is enhanced by horizontal vortex stretching near the equator, and subsequently modified by horizontal vortex tilting terms to generate meridional shear υ z off of the equator. Parameterized turbulence in the sheared flow of the cold cusp is triggered daily by the descent of the surface mixing layer associated with the weakening of the stabilizing surface buoyancy flux in the afternoon. Observational evidence for off-equatorial deep-cycle turbulence is restricted to a few CTD casts, which, when combined with shear from shipboard ADCP data, suggest the presence of marginally stable flow in TIW cold cusps. This study motivates further observational c aigns to characterize the modulation of deep-cycle turbulence by TIWs both on and off the equator.
Modulation of Tropical Instability Wave Intensity by Equatorial Kelvin Waves
Publisher: American Meteorological Society
Date: 09-2016
Abstract: Tropical instability waves (TIWs) and equatorial Kelvin waves are dominant sources of intraseasonal variability in the equatorial Pacific Ocean, and both play important roles in the heat and momentum budgets of the large-scale flow. While in idually they have been well studied, little is known about how these two features interact, although satellite observations suggest that TIW propagation speed and litude are modulated by Kelvin waves. Here, the influence of Kelvin waves on TIW kinetic energy (TIWKE) is examined using an ensemble set of 1/4° ocean model simulations of the equatorial Pacific Ocean. The results suggest that TIWKE can be significantly modified by 60-day Kelvin waves. To leading order, TIWs derive kinetic energy from the meridional shear and available potential energy of the background zonal currents, while losing TIWKE to friction and the radiation of waves. The passage of Kelvin waves disrupts this balance. Downwelling (upwelling) Kelvin waves induce decay (growth) in TIWKE through modifications to the background currents and the TIWs’ Reynolds stresses. These modulations in TIWKE affect eddy heat fluxes and the downward radiation of waves, with implications for the variability of SST and the energetics of abyssal flows in the eastern equatorial Pacific.
Adiabatic and Diabatic Signatures of Ocean Temperature Variability
Publisher: American Meteorological Society
Date: 03-2022
Abstract: Anthropogenically induced radiative imbalances in the climate system lead to a slow accumulation of heat in the ocean. This warming is often obscured by natural modes of climate variability such as El Niño–Southern Oscillation (ENSO), which drive substantial ocean temperature changes as a function of depth and latitude. The use of watermass coordinates has been proposed to help isolate forced signals and filter out fast adiabatic processes associated with modes of variability. However, how much natural modes of variability project into these different coordinate systems has not been quantified. Here we apply a rigorous framework to quantify ocean temperature variability using both a quasi-Lagrangian, watermass-based temperature coordinate and Eulerian depth and latitude coordinates in a free-running climate model under preindustrial conditions. The temperature-based coordinate removes the adiabatic component of ENSO-dominated interannual variability by definition, but a substantial diabatic signal remains. At slower (decadal to centennial) frequencies, variability in the temperature- and depth-based coordinates is comparable. Spectral analysis of temperature tendencies reveals the dominance of advective processes in latitude and depth coordinates while the variability in temperature coordinates is related closely to the surface forcing. Diabatic mixing processes play an important role at slower frequencies where quasi-steady-state balances emerge between forcing and mixing in temperature, advection and mixing in depth, and forcing and advection in latitude. While watermass-based analyses highlight diabatic effects by removing adiabatic variability, our work shows that natural variability has a strong diabatic component and cannot be ignored in the analysis of long-term trends. Quantifying the ocean warming associated with anthropogenically induced radiative imbalances in the climate system can be challenging due to the superposition with modes of internal climate variability such as El Niño. One method proposed to address this issue is the analysis of temperature changes in fluid-following (or “watermass”) coordinates that filter out fast adiabatic processes associated with these modes of variability. In this study we compare a watermass-based analysis with more traditional analyses of temperature changes at fixed depth and latitude to show that even natural modes of climate variability exhibit a substantial signal in watermass coordinates, particularly at decadal and slower frequencies. This natural variability must be taken into account when analyzing long-term temperature trends in the ocean.
Abyssal ocean overturning shaped by seafloor distribution
Publisher: Springer Science and Business Media LLC
Date: 09-11-2017
DOI: 10.1038/NATURE24472
Abstract: The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows-referred to as the abyssal overturning circulation-is key to quantifying the ocean's ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32° S, the depth distribution of the seafloor compels dense southern-origin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure.
The state of implementing big data in banking business processes: An Indonesian perspective
Publisher: LLC CPC Business Perspectives
Date: 19-09-2022
DOI: 10.21511/BBS.17(3).2022.10
Abstract: Notwithstanding the perceived global potentiality, how big data enhances decision-making quality prompts an intriguing inquiry, especially in an increasingly competitive banking environment in developing economies. Building on an industry data-driven framework, this study strives to understand the state of implementing big data in the Indonesian banking sector. A deductively organized descriptive method employing in-depth interviews was conducted with subject matter experts representing Indonesian banking-related areas. The result and the following analysis show the modest status of big data implementation across three major banks and two complementary companies, as indicated by many elements of the framework phases that were found during the early adoption stage. This denotes a steady buy-in across banking business processes as particularly reflected in the framework’s four phases – continuing push to meet the variety aspect (intelligence), structured data architecture domination (design), limited choice of performance indicator for big data value (choice), and customer–corporate vision decoupling (implementation). While Indonesian banks have evidently initiated the big data implementation, further improvement remains imperative for the decision-making process. Accordingly, big data should be tightly coupled with a strong data-driven vision that drives decision-making across intra-firm actors. Handling data omnipresence shall be viewed as the embodiment of a data-driven vision.
What is the heat uptake potential of Antarctic Bottom Water?
Publisher: Copernicus GmbH
Date: 03-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-3825
Abstract: & & Antarctic Bottom Water (AABW) is a cold dense water mass which sinks around Antarctica keeping the abyssal ocean relatively cool. Recent observations have suggested a component of recent deep ocean warming is linked to AABW. Here we explore how much changes in AABW could affect changes in vertical ocean heat transport in a warming climate. If the AABW circulation were to be completely extinguished, for ex le due to increases in upper ocean thermal stratification, AABW would cease to cool the deep ocean and hence lead to an effective warming of the abyss. Therefore, we propose that long term mean vertical heat transport of the AABW circulation is an effective upper bound on the change in heat transport that can be affected by changes in AABW. We call this upper bound the & #8216 heat uptake potential& #8217 . We analyse AABW circulations in an ensemble of numerical climate models. We find that the AABW circulation contributes between 0.05Wm& sup& -2& /sup& and 0.15Wm& sup& -2& /sup& to the global vertical heat balance in the model& #8217 s pre-industrial states. Indeed, under abrupt CO& sub& & /sub& forcing changes, AABW heat transport systematically reduces (in some cases completely), with the largest reductions occurring in models with the largest pre-industrial mean heat transports. The AABW circulation vertical heat transport is found to be highly correlated with the minimum of the Meridional Overturning Circulation at 50& sup& o& /sup& S in the models, suggesting there may be observable constraints on the heat uptake potential of AABW.& &
Embedding governance risk and compliance (GRC) elements in business process modeling
Publisher: IEEE
Date: 11-2018
Observations of Submesoscale Variability and Frontal Subduction within the Mesoscale Eddy Field of the Tasman Sea
Publisher: American Meteorological Society
Date: 05-2020
Abstract: Submesoscale lenses of water with anomalous hydrographic properties have previously been observed in the East Australian Current (EAC) system, embedded within the thermocline of mesoscale anticyclonic eddies. The waters within these lenses have high oxygen content and temperature–salinity properties that signify a surface origin. However, it is not known how these lenses form. This study presents field observations that provide insight into a possible generation mechanism via subduction at upper-ocean fronts. High-resolution hydrographic and velocity measurements of submesoscale activity were taken across a front between a mesoscale eddy dipole downstream of the EAC separation point. The front had O (1) Rossby number, strong vertical shear, and flow conducive to symmetric instability. Frontogenesis was measured in conjunction with subduction of an anticyclonic water parcel, indicative of intrathermocline eddy formation. Twenty-five years of satellite imagery reveals the existence of strong mesoscale strain coupled with strong temperature fronts in this region and indicates the conditions that led to frontal subduction observed here are a persistent feature. These processes impact the vertical export of tracers from the surface and dissipation of mesoscale kinetic energy, implicating their importance for understanding regional ocean circulation and biological productivity.
Evidence for seafloor‐intensified mixing by surface‐generated equatorial waves
Publisher: American Geophysical Union (AGU)
Date: 04-02-2016
DOI: 10.1002/2015GL066472
Popout transitions in weakly stretched single-chain multi-block copolymers in poor solvents
Publisher: IOP Publishing
Date: 09-2011
Potential Vorticity Dynamics of Tropical Instability Vortices
Publisher: American Meteorological Society
Date: 03-2014
Abstract: Tropical instability vortices (TIVs) in the equatorial Pacific exhibit energetic horizontal and vertical circulation characterized by regions of high Rossby number and low Richardson number. Their strong anticyclonic vorticity and vertical shear can influence the broader-scale circulation by driving lateral mixing and vertical exchange between the ocean surface and interior. The authors use a set of nested high-resolution simulations of the equatorial Pacific, with a finest grid size of 3 km, to examine the vortex dynamics associated with TIV core water formation. TIV cores are characterized by low values of the Ertel potential vorticity (PV) as the relative vorticity is anticyclonic with magnitude comparable to the local Coriolis parameter. A study of the variation of PV and other scalars along Lagrangian fluid parcel tracks entering the TIVs shows that the low-PV water in their cores is a mix of Equatorial Undercurrent (EUC) water and North Equatorial Counter Current (NECC) water. The EUC water is characterized by strong horizontal vorticity, and thus, the baroclinic component of the PV is nonnegligible and acts as a source for the anticyclonic vorticity of TIVs. This horizontal vorticity is tilted by an ageostrophic secondary circulation associated with strain-induced frontogenesis that tends to form along the path of the EUC water that enters the vortex. Frontogenesis disrupts the cyclogeostrophic balance of the frontal flow and drives differential vertical motions across the front. These results emphasize the role of submesoscale physics in the equatorial region, which are active when both the Rossby and Richardson numbers are O(1).
Super Residual Circulation: a new perspective on ocean vertical heat transport
Publisher: American Meteorological Society
Date: 21-05-2021
Abstract: Ocean circulation and mixing regulate Earth’s climate by moving heat vertically within the ocean. We present a new formalism to diagnose the role of ocean circulation and diabatic processes in setting vertical heat transport in ocean models. In this formalism we use temperature tendencies, rather than explicit vertical velocities to diagnose circulation. Using quasi-steady state simulations from the Australian Community Climate and Earth-System Simulator Ocean Model (ACCESS-OM2), we diagnose a diathermal overturning circulation in temperature-depth space. Furthermore, projection of tendencies due to diabatic processes onto this coordinate permits us to represent these as apparent overturning circulations. Our framework permits us to extend the concept of Super-Residual Transport (SRT), which combines mean and eddy advection terms with subgridscale isopycnal mixing due to mesoscale eddies, but excludes small-scale three dimensional turbulent mixing effect, to construct a new overturning circulation – the ‘Super Residual Circulation’ (SRC). We find that in the coarse resolution version of ACCESS-OM2 (nominally 1° horizontal resolution) the SRC is dominated by an ~11 Sv circulation which transports heat upward. The SRC’s upward heat transport is ~2 times larger in a finer horizontal resolution (0.1°) version of ACCESS, suggesting a differing balance of super-residual and parameterized small-scale processes may emerge as eddies are resolved. Our analysis adds new insight into super-residual processes, as the SRC elucidates the pathways in temperature and depth space along which watermass transformation occurs.
From Mixing to the Large Scale Circulation: How the Inverse Cascade Is Involved in the Formation of the Subsurface Currents in the Gulf of Guinea.
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-5371
Abstract: & & We analyse the results from a numerical model at high resolution. We focus on the formation and maintenance of subsurface equatorial currents in the Gulf of Guinea and we base our analysis on the evolution of potential vorticity (PV). We highlight the link between submesoscale processes (involving mixing, friction and filamentation), mesoscale vortices and the mean currents in the area. In the simulation, eastward currents, the South and North Equatorial Undercurrents (SEUC and NEUC respectively) and the Guinea Undercurrent (GUC), are shown to be linked to the westward currents located equatorward. We show that east of 20& sup& & #9702 & /sup& W, both westward and eastward currents are associated with the spreading of PV tongues by mesoscale vortices. The Equatorial Undercurrent (EUC) brings salty waters into the Gulf of Guinea. Mixing diffuses the salty anomaly downward. Meridional advection, mixing and friction are involved in the formation of fluid parcel swith PV anomalies in the lower part and below the pycnocline, north and south of the EUC, in the Gulf of Guinea. These parcels gradually merge and vertically align, forming nonlinear anticyclonic vortices that propagate westward, spreading and horizontally mixing their PV content by stirring filamentation and diffusion, up to 20& sup& & #9702 & /sup& W. When averaged over time, this creates regions of nearly homogeneous PV within zonal bands between 1.5& sup& & #9702 & /sup& and 5& sup& & #9702 & /sup& S or N. This mean PV field is associated with westward and eastward zonal jets flanking the EUC with the homogeneous PV tongues corresponding to the westward currents, and the strong PV gradient regions at their edges corresponding to the eastward currents. Mesoscale vortices strongly modulate the mean fields explaining the high spatial and temporal variability of the jets.& &
The Influence of Business Process Representation on Performance of Different Task Types
Publisher: American Accounting Association
Date: 11-02-2020
DOI: 10.2308/ISYS-52385
Abstract: The analysis of business processes is an integral part of audit methodology. In both auditing research and process modeling research, there is an ongoing debate on which representation format might be best suited to support analysis tasks. Most important in this context is the question of whether process models as visual representation might be superior to textual narratives. This paper investigates the affinity of different tasks with two process representational formats: textual narratives and visual diagrams (BPMN models). Our findings demonstrate that the representation format has an impact on task performance and that the direction of this impact depends upon the affinity of the tasks type with the representation format. This implies that auditors are best provided with different process representations, depending on the task they are performing. These findings have important implications for research on auditing tasks, and more broadly also for software engineering and information systems research.
In-app controls for small business accounting information system: a study of domain understanding
Publisher: Emerald
Date: 12-11-2019
DOI: 10.1108/JSBED-12-2018-0372
Abstract: The purpose of this paper is to examine the context of cognitive load and the role of in-app controls that serve as visual aids to promote business process understanding and the use of accounting information system (AIS) for small business users. In total, 164 participants from small- and medium-sized enterprises were invited to participate in an experiment with between-subjects 2×2 factorial design. Researchers provided two sets of manipulations in the form of in-app control aids, namely Navigation and Guidance. Groups of in iduals either received both navigation and guidance, only navigation or only guidance, or no treatment at all. These four different groups were then tested by a range of tasks to measure user understanding on small business domain knowledge and accounting business process provided by the system. The findings indicate that although several early indications were visually observed wherein Navigation and Guidance may help reduce in idual cognitive load and hence provide potential value for a better understanding of business process, the statistical analysis has not yet been able to substantiate the differences. Despite visually supporting the hypotheses, neither Navigation nor Guidance proved significant on accuracy (scores), efficiency (time) and in idual cognitive difficulties. It appears that a systematic training on the accounting process is arguably imperative in order to reduce the extraneous cognitive load due to a relative gap of accounting logic and users’ knowledge of their business process. Ultimately, it would promote the germane knowledge where the integration of user’s own business process and accounting process can manifest effectively. Aligned with the findings of the research and its correlation with learning, apparently the learning process is not merely determined not only by the application control features being embedded, but also by the domain knowledge of in iduals who interact with the system. Training related to the discussion of the accounting process should be conducted more intensively to minimize the gap between the knowledge upon the problems on in idual business process and the mechanism of the accounting process. This research takes a new approach in examining user acceptance toward an AIS by comparing task performance with and without the assistive devices, to assess how these visual aids may overcome the cognitive load of the in idual.
Barotropic Kelvin Wave‐Induced Bottom Boundary Layer Warming Along the West Antarctic Peninsula
Publisher: American Geophysical Union (AGU)
Date: 03-2019
DOI: 10.1029/2018JC014227
Atlantic Ocean Heat Transport Enabled by Indo‐Pacific Heat Uptake and Mixing
Publisher: American Geophysical Union (AGU)
Date: 11-12-2019
DOI: 10.1029/2019GL085160
Sensitivity of a Coarse-Resolution Global Ocean Model to Spatially Variable Neutral Diffusion
Publisher: Wiley
Date: 24-11-2021
The Geography of Numerical Mixing in a Suite of Global Ocean Models
Publisher: American Geophysical Union (AGU)
Date: 07-2021
DOI: 10.1029/2020MS002333
Abstract: Numerical mixing, defined here as the physically spurious tracer diffusion due to the numerical discretization of advection, is known to contribute to biases in ocean models. However, quantifying numerical mixing is nontrivial, with most studies utilizing targeted experiments in idealized settings. Here, we present a water mass transformation‐based method for quantifying numerical mixing that can be applied to any conserved variable in general circulation models. Furthermore, the method can be applied within in idual fluid columns to provide spatial information. We apply the method to a suite of global ocean model simulations with differing grid spacings and subgrid‐scale parameterizations. In all configurations numerical mixing drives diathermal heat transport of comparable magnitude to that associated with explicit parameterizations. Numerical mixing is prominent in the tropical thermocline, where it is sensitive to the vertical diffusivity and resolution. At colder temperatures numerical mixing is sensitive to the presence of explicit neutral diffusion, suggesting that it may act as a proxy for neutral diffusion when it is explicitly absent. Comparison of otherwise equivalent 1/4° and 1/10° configurations with grid‐scale dependent horizontal viscosity shows only a modest enhancement in numerical mixing at 1/4°. However, if the lateral viscosity is maintained while resolution is increased then numerical mixing is reduced by almost 35 % . This result suggests that the common practice of reducing viscosity in order to maximize permitted variability must be considered carefully. Our results provide a detailed view of numerical mixing in ocean models and pave the way for improvements in parameter choices and numerical methods.
Diapycnal Transport near a Sloping Bottom Boundary
Publisher: American Meteorological Society
Date: 11-2020
Abstract: The diapycnal motion in the stratified ocean near a sloping bottom boundary is studied using analytical solutions from one-dimensional boundary layer theory. Bottom-intensification of the diapycnal mixing intensity ensures that in the stratified mixing layer (SML), where isopycnals are relatively flat, the diapycnal motion is downward toward denser fluid. In contrast, convergence of the diffusive buoyancy flux near the seafloor drives diapycnal upwelling in what we define as the bottom boundary layer (BBL). Much of the one-dimensional BBL is characterized by a stratification only slightly reduced from that in the SML because the maximum in the buoyancy flux at the top of the BBL, where the diapycnal velocity changes sign, must occur in well-stratified fluid. The diapycnal upwelling in the BBL is determined by variations not only in the magnitude of the buoyancy gradient but also in the curvature of isopycnals. The net diapycnal upwelling is concentrated in the bottom half of the BBL where the magnitude of the buoyancy gradient changes most rapidly. The curvature effect drives upwelling near the seafloor that only makes a significant contribution to the net upwelling for steep slopes. The structure of the diapycnal velocity in this stratified BBL differs from the case of a turbulent well-mixed BBL that has been assumed in some recent theoretical studies on bottom-intensified mixing. This work therefore extends recent theories in a way that should be more applicable to abyssal ocean observations where well-mixed BBLs are not common.
Climate Recorded in Seawater: A Workshop on Water-Mass Transformation Analysis for Ocean and Climate Studies
Publisher: American Meteorological Society
Date: 09-2019
Ridges, Seamounts, Troughs, and Bowls: Topographic Control of the Dianeutral Circulation in the Abyssal Ocean
Publisher: American Meteorological Society
Date: 04-2018
Abstract: In situ observations obtained over the last several decades have shown that the intensity of turbulent mixing in the abyssal ocean is enhanced toward the seafloor. Consequently, a new paradigm has emerged whereby dianeutral downwelling dominates in the ocean interior and dianeutral upwelling only occurs within thin bottom boundary layers. This study shows that when mixing is bottom intensified the net abyssal dianeutral transports and the stratification can depend on subtle features of the seafloor geometry. Under an assumption of depth-independent net dianeutral upwelling, small changes in the curvature of the seafloor can result in interior stratification that is bottom intensified, uniform, or surface intensified. Further, when the net dianeutral transport is allowed to vary in the vertical, changes in the seafloor slope and bathymetric contour length with height can drive lateral exchange between the boundary layer and interior, with particularly strong lateral outflows predicted at the crests of midocean ridges. Finally, using a realistic neutral density climatology the authors suggest that the increase in the perimeter of abyssal neutral density surfaces with height drives much of the dianeutral upwelling at depths greater than 4 km, while the increase in the slope of the seafloor at shallower depths acts to oppose upwelling. These results add to a growing body of literature highlighting the key control of seafloor geometry on the abyssal overturning circulation.
Critical Success Factors Enterprise Resource Planning (ERP) Implementation in Higher Education
Publisher: Universitas Padjadjaran
Date: 16-01-2021
Abstract: One of the technologies that can optimize the data management system in Higher Education is the Enterprise Resource Planning (ERP) information system. However, in its implementation, failures often occur. This research was conducted to formulate the key factors for the successful implementation of ERP systems in universities. The research method used is descriptive qualitative through case studies on 4 c uses in West Java. The 20 key factors taken are the result of iterations of 32 works of literature in the 2016-2019 timeframe. The results of the study provide an overview of the key success factors that have emerged at each college and university.
JOURNEY AND PERFORMANCE OF E-TAX INVOICING IN INDONESIA: A SYSTEMATIC LITERATUR REVIEW
Publisher: Universitas Airlangga
Date: 26-05-2023
DOI: 10.20473/JRABA.V8I1.42077
Abstract: This study aims to analyze the development of research results in relation to the implementation, issues, and problems of performance of e-tax invoicing in Indonesia to determine benefits of e-tax invoicing implementation for improving compliance how do users perceive the implementation e-tax invoicing and what is the impact of the performance of e-tax invoicing in increasing state revenue. This study uses a Systematic Literature Review method that systematically identify and review journal articles to answer the research questions. The PRISMA protocol was established by selecting articles obtained from the Google Scholar database, identifying them based on the year of the article from 2014 to 2022, screening by applying quality assessment and criteria of limitations, and reviewing the eligibility of articles resulting in the remaining 28 articles from accredited journal. The results indicate that: (i) on the subject research of the development of e-tax invoicing in Indonesia discussed the implementation of e-tax invoicing, and analyzed the issues and problems arising from changes in e-tax invoicing from one period to another (ii) e-tax invoicing plays a role in increasing taxpayer compliance in administration of Value Added Tax reporting (iii) the perceptions of e-tax invoice users about the usability and convenience of e-tax invoicing, have affected the use of etax invoicing, and the quality of the system affects user satisfaction (iv) e-tax invoicing ultimately lead to an increase in state revenue. This study is expected to enrich the literature related to e-tax invoicing in Indonesia so that other researchers can develop another topic on e-tax invoicing. Practically, this study also can be used by the government to develop policies and revise regulations related to tax collection, especially Value Added Tax. It can also provide consideration to tax payer in deciding to use e-tax invoicing from Directorate General of Taxation or host-to-host etax invoicing.
The interpretation of temperature and salinity variables in numerical ocean model output, and the calculation of heat fluxes and heat content
Publisher: Copernicus GmbH
Date: 19-01-2021
DOI: 10.5194/GMD-2020-426
Abstract: Abstract. The 2010 international thermodynamic equation of seawater, TEOS-10, defined the enthalpy and entropy of seawater, thus enabling the global ocean heat content to be calculated as the volume integral of the product of in situ density, ρ, and potential enthalpy, h0 (with reference sea pressure of 0 dbar). In terms of Conservative Temperature, Θ, ocean heat content is the volume integral of ρcp0Θ, where cp0 is a constant isobaric heat capacity. However, several ocean models in CMIP6 (as well as all of those in previous Coupled Model Intercomparison Project phases, such as CMIP5) have not been converted from EOS-80 (Equation of State - 1980) to TEOS-10, so the question arises of how the salinity and temperature variables in these models should be interpreted. In this article we address how heat content, surface heat fluxes and the meridional heat transport are best calculated in these models, and also how these quantities should be compared with the corresponding quantities calculated from observations. We conclude that even though a model uses the EOS-80 equation of state which expects potential temperature as its input temperature, the most appropriate interpretation of the model's temperature variable is actually Conservative Temperature. This interpretation is needed to ensure that the air-sea heat flux that leaves/arrives-in the atmosphere is the same as that which arrives-in/leaves the ocean. We also show that the salinity variable carried by TEOS-10 based models is Preformed Salinity, while the prognostic salinity of EOS-80 based models is also proportional to Preformed Salinity. These interpretations of the salinity and temperature variables in ocean models are an update on the comprehensive Griffies et al. (2016) paper that discusses the interpretation of many aspects of coupled model runs.
Single Chain Asymmetric Block Copolymers in Poor Solvents. Candidates for Patchy Colloids
Publisher: American Chemical Society (ACS)
Date: 13-07-2011
DOI: 10.1021/MA200085W
Recent trajectory of ocean heat uptake estimated from novel 1972-2017 ocean sea-ice model hindcast simulations
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-8096
Abstract: & & Uptake and storage of heat by the ocean plays a critical role in modulating the Earth's climate system. In the last 50 years, the ocean has absorbed over 90% of the additional energy accumulating in the Earth system due to radiative imbalance. However, our knowledge about ocean heat uptake (OHU), transport and storage is strongly constrained by the sparse observational record with large uncertainties. In this study, we conduct a suite of historical 1972& #8211 hindcast simulations using a global ocean-sea ice model that are specifically designed to account for a cold start climate and model drift. The hindcast simulations are initialised from an equilibrated control simulation that uses repeat decade forcing over the period 1962-1971. This repeat decade forcing approach is a compromise between an early unobserved period (where our confidence in the forcing is low) and later periods (which would result in a shorter experiment period and a smaller fraction of the total OHU). The simulations are aimed at giving a good estimate of the trajectory of OHU in the tropics, the extratropics and in idual ocean basins in recent decades. Many modelling studies that look at recent OHU rates so far use a simpler approach for the forcing. For ex le, they use repeating cycles of 1950-2010 Coordinated Ocean Reference Experiment (CORE) forcing that is consistent with the Ocean Model Intercomparison Project 2 (OMIP-2). However, this approach cannot account for model drift. The new simulations here highlight the dominant role of the extratropics, and in particular the Southern Ocean in OHU. In contrast, little heat is absorbed in the tropics and simulations forced with only tropical trends in atmospheric forcing show only weak global ocean heat content trends. Almost 50% of the heat taken up from the atmosphere in the Southern Ocean is transported into the Atlantic Ocean. Two-thirds of this Southern Ocean-sourced heat is then subsequently lost to the atmosphere in the North Atlantic but nevertheless this basin gains heat overall. Our results help to estimate the large-scale cycling of anthropogenic heat within the ocean today and have implications for heat content trends under a changing climate.& &
ACCESS-OM2 v1.0: a global ocean–sea ice model at three resolutions
Publisher: Copernicus GmbH
Date: 05-02-2020
Abstract: Abstract. We introduce ACCESS-OM2, a new version of the ocean–sea ice model of the Australian Community Climate and Earth System Simulator. ACCESS-OM2 is driven by a prescribed atmosphere (JRA55-do) but has been designed to form the ocean–sea ice component of the fully coupled (atmosphere–land–ocean–sea ice) ACCESS-CM2 model. Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1∘ horizontal grid spacing), an eddy-permitting resolution (nominally 0.25∘), and an eddy-rich resolution (0.1∘ with 75 vertical levels) the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system. The different resolutions have been developed simultaneously, both to allow for testing at lower resolutions and to permit comparison across resolutions. In this paper, the model is introduced and the in idual components are documented. The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running ocean–sea ice models at higher resolution. We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents, and the abyssal overturning cell but that there is scope for improvements in sub-grid-scale parameterizations at the highest resolution.
Adiabatic and diabatic signatures of ocean temperature variability
Publisher: Copernicus GmbH
Date: 27-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-2085
Abstract: & & Anthropogenically induced radiative imbalances in the climate system lead to a slow accumulation of heat in the ocean. This warming is often obscured by natural modes of climate variability such as the El Nino-Southern Oscillation (ENSO), which drive substantial ocean temperature changes as a function of depth and latitude. The use of watermass coordinates has been proposed to help isolate forced signals and filter out fast adiabatic processes associated with modes of variability. However, how much natural modes of variability project into these different coordinate systems has not been quantified. Here we apply a rigorous framework to quantify ocean temperature variability using both a quasi-Lagrangian watermass-based temperature coordinate and Eulerian depth and latitude coordinates in a free-running climate model under pre-industrial conditions. The temperature-based coordinate effectively filters out the adiabatic component of ENSO-dominated interannual variability, while a substantial diabatic signal remains. At slower (decadal to centennial) frequencies, variability in the temperature- and depth-based coordinates is comparable. Spectral analysis of temperature tendencies reveals the dominance of advective processes in latitude- and depth-coordinates while the variability in temperature-coordinates is related closely to the surface forcing. Diabatic mixing processes play an important role at slower frequencies where quasi steady-state balances emerge between forcing and mixing in temperature, advection and mixing in depth and forcing and advection in latitude. Our work suggests that watermass based analyses accurately filter out adiabitic variability and highlight diabatic effects, but also that natural variability has a strong diabatic component and can not be ignored in the analysis of long term trends.& &
Tracer Transport within Abyssal Mixing Layers
Publisher: American Meteorological Society
Date: 10-2019
Abstract: Mixing layers near sloped topography in the abyss are thought to play a critical role in the global overturning circulation. Yet the behavior of passive tracers within sloping boundary layer systems has received little attention, despite the extensive use of tracer observations to understand abyssal circulation. Here, we investigate the behavior of a passive tracer released near a sloping boundary within a flow governed by one-dimensional boundary layer theory. The spreading rate of the tracer across isopycnals is influenced by factors such as the bottom-intensification of mixing, the dipole of upwelling (in the boundary layer) and downwelling (in the outer mixing layer), and along-isopycnal diffusion. For isolated near-boundary tracer releases, the bulk diffusivity, proportional to the rate of increase of the variance of the tracer distribution in buoyancy space, is much less than what would be expected from averaging the diapycnal diffusivity over the tracer patch. This stems from the presence of the bottom boundary that prevents tracer diffusion through it. Furthermore, when along-isopycnal diffusion is weak, the boundary tends to drive the tracer up the slope toward less dense fluid on average due to asymmetries between boundary layer and interior flows. With strong along-isopycnal diffusion this upslope movement is reduced, while at the same time the average diapycnal spreading rate is increased due to a reduced influence of the bottom boundary. These results have implications for what can be learned about the characteristics of mixing near sloping boundaries from past and future tracer-release experiments.
Fraud analytics practices in public-sector transactions: a systematic review
Publisher: Emerald
Date: 17-10-2023
Blockchain Disruption on Management Accountant's Role: Systematic Literature Review
Publisher: Universitas Padjadjaran
Date: 13-01-2021
Abstract: Blockchain considered as an emerging technology that potentially disrupts how management accountant work and his role. This research intends to understand what Blockchain’s capabilities will disrupt the profession by conducting a systematic literature review (SLR). A protocol of SLR is inspired by Kitchenham, Van Akthley, and Okoli in their works. The protocol consists of identifying purpose and outcome research, definition research question, preparing search and review protocol, title and abstract screening, paper quality assessment, data extraction, and data analysis. MAXQDA was used to conduct the SLR protocol. Seven academic journal databases were used in the searching stage. Kitchenham’s guidelines inspire data extraction and narrative synthesis. This study finds that Blockchain enables the user to do real-time accounting, gather data for supervising and monitoring function, and streamline the accounting practice process. With these findings, the management accountant can prepare to blockchain disruption by upgrading his analytics and computation skills.
Sensitivity of a Coarse‐Resolution Global Ocean Model to a Spatially Variable Neutral Diffusivity
Publisher: American Geophysical Union (AGU)
Date: 03-2022
DOI: 10.1029/2021MS002914
Abstract: Motivated by recent advances in mapping mesoscale eddy tracer mixing in the ocean we evaluate the sensitivity of a coarse‐resolution global ocean model to a spatially variable neutral diffusion coefficient κ n ( x , y , z ). We gradually introduce physically motivated models for the horizontal (mixing length theory) and vertical (surface mode theory) structure of κ n along with suppression of mixing by mean flows. Each structural feature influences the ocean's hydrography and circulation to varying extents, with the suppression of mixing by mean flows being the most important factor and the vertical structure being relatively unimportant. When utilizing the full theory (experiment “FULL”) the interhemispheric overturning cell is strengthened by 2 Sv at 26°N (a ∼20% increase), bringing it into better agreement with observations. Zonal mean tracer biases are also reduced in FULL. Neutral diffusion impacts circulation through surface temperature‐induced changes in surface buoyancy fluxes and nonlinear equation of state effects. Surface buoyancy forcing anomalies are largest in the Southern Ocean where a decreased neutral diffusivity in FULL leads to surface cooling and enhanced dense‐to‐light surface water mass transformation, reinforced by reductions in cabbeling and thermobaricity. The increased water mass transformation leads to enhanced midlatitude stratification and interhemispheric overturning. The spatial structure for κ n in FULL is important as it enhances the interhemispheric cell without degrading the Antarctic bottom water cell, unlike a spatially uniform reduction in κ n . These results highlight the sensitivity of modeled circulation to κ n and motivate the use of physics‐based models for its structure.
Fifty Year Trends in Global Ocean Heat Content Traced to Surface Heat Fluxes in the Sub‐Polar Ocean
Publisher: American Geophysical Union (AGU)
Date: 24-04-2021
DOI: 10.1029/2020GL091439
Abstract: The ocean has absorbed approximately 90% of the accumulated heat in the climate system since 1970. As global warming accelerates, understanding ocean heat content changes and tracing these to surface heat input is increasingly important. We introduce a novel framework by organizing the ocean into temperature‐percentiles from warmest to coldest, allowing us to trace ocean temperature changes to changes in surface fluxes and mixing. Applying this framework to observations and historical CMIP6 simulations, we find that 50 ± 6% of surface heat uptake between 1970 and 2014 is confined to isotherms in the coldest 90% of the ocean volume. These isotherms outcrop over only 23% of the ocean's surface area in the sub‐polar regions, implying a disproportionately large heat input per unit area. Additionally, a cooling bias in the CMIP6 models is traced to inaccurate sea surface temperatures and surface heat fluxes into the warmest 5%–20% of the ocean volume.
Watermass co-ordinates isolate the historical climate change signal
Publisher: Wiley
Date: 18-05-2022
ACCESS Datasets for CMIP6: Methodology & Idealised Experiments
Publisher: CSIRO Publishing
Date: 14-07-2022
DOI: 10.1071/ES21031
Abstract: The Australian Community Climate and Earth System Simulator (ACCESS) has contributed to the World Climate Research Programme’s Coupled Model Intercomparison Project Phase 6 (CMIP6) using two fully coupled model versions (ACCESS-CM2 and ACCESS-ESM1.5) and two ocean–sea-ice model versions (1° and 0.25° resolution versions of ACCESS-OM2). The fully coupled models differ primarily in the configuration and version of their atmosphere components (including the aerosol scheme), with smaller differences in their sea-ice and land model versions. Additionally, ACCESS-ESM1.5 includes biogeochemistry in the land and ocean components and can be run with an interactive carbon cycle. CMIP6 comprises core experiments and associated thematic Model Intercomparison Projects (MIPs). This paper provides an overview of the CMIP6 submission, including the methods used for the preparation of input forcing datasets and the post-processing of model output, along with a comprehensive list of experiments performed, detailing their initialisation, duration, ensemble number and computational cost. A small selection of model output is presented, focusing on idealised experiments and their variants at global scale. Differences in the climate simulation of the two coupled models are highlighted. ACCESS-CM2 produces a larger equilibrium climate sensitivity (4.7°C) than ACCESS-ESM1.5 (3.9°C), likely a result of updated atmospheric parameterisation in recent versions of the atmospheric component of ACCESS-CM2. The idealised experiments run with ACCESS-ESM1.5 show that land and ocean carbon fluxes respond to both changing atmospheric CO2 and to changing temperature. ACCESS data submitted to CMIP6 are available from the Earth System Grid Federation (0.22033/ESGF/CMIP6.2281 and 0.22033/ESGF/CMIP6.2288). The information provided in this paper should facilitate easier use of these significant datasets by the broader climate community.
From Mixing to the Large Scale Circulation: How the Inverse Cascade Is Involved in the Formation of the Subsurface Currents in the Gulf of Guinea
Publisher: MDPI AG
Date: 29-08-2020
Abstract: In this paper, we analyse the results from a numerical model at high resolution. We focus on the formation and maintenance of subsurface equatorial currents in the Gulf of Guinea and we base our analysis on the evolution of potential vorticity (PV). We highlight the link between submesoscale processes (involving mixing, friction and filamentation), mesoscale vortices and the mean currents in the area. In the simulation, eastward currents, the South and North Equatorial Undercurrents (SEUC and NEUC respectively) and the Guinea Undercurrent (GUC), are shown to be linked to the westward currents located equatorward. We show that east of 20° W, both westward and eastward currents are associated with the spreading of PV tongues by mesoscale vortices. The Equatorial Undercurrent (EUC) brings salty waters into the Gulf of Guinea. Mixing diffuses the salty anomaly downward. Meridional advection, mixing and friction are involved in the formation of fluid parcels with PV anomalies in the lower part and below the pycnocline, north and south of the EUC, in the Gulf of Guinea. These parcels gradually merge and vertically align, forming nonlinear anticyclonic vortices that propagate westward, spreading and horizontally mixing their PV content by stirring filamentation and diffusion, up to 20° W. When averaged over time, this creates regions of nearly homogeneous PV within zonal bands between 1.5° and 5° S or N. This mean PV field is associated with westward and eastward zonal jets flanking the EUC with the homogeneous PV tongues corresponding to the westward currents, and the strong PV gradient regions at their edges corresponding to the eastward currents. Mesoscale vortices strongly modulate the mean fields explaining the high spatial and temporal variability of the jets.
The Impact of Indonesian Throughflow Constrictions on Eastern Pacific Upwelling and Water‐Mass Transformation
Publisher: American Geophysical Union (AGU)
Date: 05-2022
DOI: 10.1029/2022JC018509
Abstract: The Indonesian Throughflow (ITF) is a key link in the global ocean overturning circulation. Heat gained from upwelling and watermass transformation in the eastern equatorial Pacific Ocean (PO) is transported through the ITF into the Indian Ocean, ultimately connecting to high‐latitude regions of heat loss such as the North Atlantic. However, state‐of‐the‐art General Circulation Models (GCMs) often poorly simulate upwelling, particularly in the eastern Pacific boundary regions. Recent studies have hypothesized that these difficulties may be related to biases in downstream ITF volume and heat transport, whereby insufficient warm surface water from the western PO passes through the ITF, a complex region that is hard to accurately represent in models. Here, we test this hypothesis using a coarse‐resolution ocean model by artificially widening the ITF and allowing greater quantities of warm water to exit the western PO. This reduces the Indo‐Pacific sea‐surface height and pressure gradient biases. Using diagnostics in temperature coordinates, we trace the source of increased ITF warm‐water transport to enhanced watermass transformation of cold‐to‐warm waters in the eastern tropical PO. Additional cool water is brought to the surface in the Cold Tongue region, resulting in an enhancement of surface flux‐driven warming. However, we find only limited evidence for changes in upwelling at lower temperatures along the eastern PO margins, considerably less than hypothesized in a previous study. Our experiment provides useful insights to help understand simulated ITF mass and heat transport biases and their links with the tropical PO in GCMs.
Propagation of barotropic Kelvin waves around Antarctica
Publisher: Springer Science and Business Media LLC
Date: 05-05-2022
DOI: 10.1007/S10236-022-01506-Y
Abstract: Barotropic (i.e., depth-uniform) coastal oceanic Kelvin waves can provide rapid teleconnections from climate and weather events in one location to remote regions of the globe. Studies suggest that barotropic Kelvin waves observed around Antarctica may provide a mechanism for rapidly propagating circulation anomalies around the continent, with implications for continental shelf temperatures along the West Antarctic Peninsula and thus Antarctic ice mass loss rates. However, how the propagation of Kelvin waves around Antarctica is influenced by features such as coastal geometry and variations in bathymetry remains poorly understood. Here we study the propagation of barotropic Antarctic Kelvin waves using a range of idealized model simulations. Using a single-layer linear shallow water model with 1 ∘ horizontal resolution, we gradually add complexity of continental configuration, realistic bathymetry, variable planetary rotation, and forcing scenarios, to isolate sources and sinks of wave energy and the mechanisms responsible. We find that approximately 75 % of sub-inertial barotropic Kelvin wave energy is scattered away from Antarctica as other waves in one circumnavigation of the continent, due mostly to interactions with bathymetry. Super-inertial barotropic Kelvin waves lose nearly 95 % of their energy in one circumpolar loop, due to interactions with both coastal geometry and bathymetry. These results help to explain why only sustained signals of low-frequency resonant barotropic Kelvin waves have been observed around Antarctica, and contribute to our understanding of the role of rapid, oceanic teleconnections in climate.
The geography of numerical mixing in a suite of global ocean models
Publisher: Wiley
Date: 29-09-2020
Review on Process Representation in Accounting Information System
Publisher: Global Academy of Training and Research (GATR) Enterprise
Date: 14-01-2015
DOI: 10.35609/GJBSSR.2015.3.1(1)
Abstract: Objective - Understanding business processes is becoming increasingly critical. In light of the understanding of business process, the notion of understandability has received much attention in accounting information system (AIS). The current study focuses on the comparison of different representation format, namely diagram-oriented and textual-oriented. Type the brief purpose of the paper and illustrate the direction that is taken, whether it is empirical or theoretical testing in analyzing the research subject. Methodology/Technique - The paper looks at, through systematic approach the collection of prior research papers relevant to the use of representation format depicting business processes and/or other information artifacts. Findings - Observable differences have been studied between different representation modes in which understandability serves as part of a dimension of interest. Experimental works It appeared that here is also inconclusive concession with regard to the review. Such a comparison is highly relevant, as business process is attributed with risks that may affect the organization at different level of exposures. This paper strives to contribute to the body of knowledge by focusing on the current state of the relationship between different process representation formats with a user utilizes in relation with a process perspective of accounting and information system. Type of Paper - Conceptual Keywords: Business Process Accounting information system Diagrammatic Textual Process Representation Experimental.
Reply to “Comments on ‘Diathermal Heat Transport in a Global Ocean Model’”
Publisher: American Meteorological Society
Date: 08-2019
Abstract: Hochet and Tailleux (2019), in a comment on Holmes et al. (2019), argue that under the incompressible Boussinesq approximation the “sum of the volume fluxes through any kind of control volume must integrate to zero at all times.” They hence argue that the expression in Holmes et al. (2019) for the change in the volume of seawater warmer than a given temperature is inaccurate. Here we clarify what is meant by the term “volume flux” as used in Holmes et al. (2019) and also more generally in the water-mass transformation literature. Specifically, a volume flux across a surface can occur either due to fluid moving through a fixed surface, or due to the surface moving through the fluid. Interpreted in this way, we show using several ex les that the statement from Hochet and Tailleux (2019) quoted above does not apply to the control volume considered in Holmes et al. (2019). Hochet and Tailleux (2019) then derive a series of expressions for the water-mass transformation or volume flux across an isotherm in the general, compressible case. In the incompressible Boussinesq limit these expressions reduce to a form (similar to that provided in Holmes et al. 2019) that involves the temperature derivative of the diabatic heat fluxes. Due to this derivative, can be difficult to robustly estimate from ocean model output. This emphasizes one of the advantages of the approach of Holmes et al. (2019), namely, does not appear in the internal heat content budget and is not needed to describe the flow of internal heat content into and around the ocean.
Robotic Process Automation in Action : A Use Case in Accounting Task
Publisher: Universitas Padjadjaran
Date: 2022
DOI: 10.24198/DIGITS.V1I1.38534
Abstract: Robotic Process Automation (RPA) allow people focus on meaningful tasks rather than transferrable recurring and non-value-added ones. Whereas it provides an opportunity to foster agility and productivity, RPA is also perceived to put accountants at risk as many repetitive processes clinging to the profession can be substituted by the technology. As there is little study on how RPA is immersed into play this research aims to fill this spot by designing RPA solution for typical accounting taks in telecommunication entity. Design science methodology (DSR) was employed to guide the process of artifact development. Building on the initial as-is process model, RPA-oriented process model was then produced and then processed according to DSR method into an instantiation. The accounting task design result shows substantive progress in average throughput time from pre-RPA task 02:41 minutes to post-RPA of 19 seconds with no error conceded, thus creating 7 times faster processing. The current research is an important breakthrough for organizations to foster adaptive business process, especially in accounting domain.
Finding the suitable process modeling for AIS teaching: An experimental study
Publisher: IEEE
Date: 10-2018
Localized rapid warming of West Antarctic subsurface waters by remote winds
Publisher: Springer Science and Business Media LLC
Date: 17-07-2017
DOI: 10.1038/NCLIMATE3335
ACCESS-OM2: A Global Ocean-Sea Ice Model at Three Resolutions
Publisher: Copernicus GmbH
Date: 30-04-2019
DOI: 10.5194/GMD-2019-106
Abstract: Abstract. We introduce a new version of the ocean-sea ice implementation of the Australian Community Climate and Earth System Simulator, ACCESS-OM2. The model has been developed with the aim of being aligned as closely as possible with the fully coupled (atmosphere-land-ocean-sea ice) ACCESS-CM2. Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1° horizontal grid spacing), an eddy-permitting resolution (nominally 0.25°) and an eddy-rich resolution (0.1° with 75 vertical levels), where the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system. The different resolutions have been developed simultaneously, both to allow testing at lower resolutions and to permit comparison across resolutions. In this manuscript, the model is introduced and the in idual components are documented. The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running ocean-sea ice models at higher resolution. We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents and the abyssal overturning cell, but that there is scope for improvements in sub-grid scale parameterisations at the highest resolution.
Internal salt content: a useful framework for understanding the oceanic branch of the water cycle
Publisher: American Meteorological Society
Date: 13-04-2021
Abstract: The global water cycle is dominated by an atmospheric branch which transfers fresh water away from subtropical regions and an oceanic branch which returns that fresh water from subpolar and tropical regions. Salt content is commonly used to understand the oceanic branch because surface freshwater fluxes leave an imprint on ocean salinity. However, freshwater fluxes do not actually change the amount of salt in the ocean and – in the mean – no salt is transported meridionally by ocean circulation. To study the processes which determine ocean salinity we introduce a new variable: “internal salt” and its counterpart “internal fresh water”. Precise budgets for internal salt in salinity coordinates relate meridional and diahaline transport to surface freshwater forcing, ocean circulation and mixing, and reveal the pathway of fresh water in the ocean. We apply this framework to a 1° global ocean model. We find that in order for fresh water to be exported from the ocean’s tropical and subpolar regions to the subtropics, salt must be mixed across the salinity surfaces that bound those regions. In the tropics, this mixing is achieved by parameterized vertical mixing, along-isopycnal mixing, and numerical mixing associated with truncation errors in the model’s advection scheme, while along-isopycnal mixing dominates at high latitudes. We analyze the internal freshwater budgets of the Indo-Pacific and Atlantic Ocean basins and identify the transport pathways between them which redistribute fresh water added through precipitation, balancing asymmetries in freshwater forcing between the basins.
Planetary-wave induced strengthening of the AMOC forced by poleward intensified Southern Hemisphere westerly winds
Publisher: American Meteorological Society
Date: 11-05-2021
Abstract: The Atlantic meridional overturning circulation (AMOC) plays a key role in determining the distribution of heat and nutrients in the global ocean. Climate models suggest that Southern Ocean winds will strengthen and shift poleward in the future, which could have implications for future AMOC trends. Using a coupled global-ocean sea-ice model at 1/4°horizontal resolution, we study the response of the North Atlantic overturning to two anomalous Southern Ocean wind-forcing ( τ +15% ), and a poleward intensification( ). In both scenarios a strengthening in the North Atlantic overturning develops within a decade, with a much stronger response in the case. In , we find that the primary link between the North Atlantic response and the Southern Ocean forcing is via the propagation of baroclinic waves. In fact, due to the rapid northward propagation of these waves, changes in the AMOC in the case appear to originate in the North Atlantic and propagate southward, whereas in the τ +15% case AMOC anomalies propagate northward from the Southern Ocean. We find the difference to be predominately caused by the sign of the baroclinic waves propagating from the forcing region into the North Atlantic downwelling in the τ +15% case, versus upwelling in the case. In the case, upwelling waves propagating into the NADW formation regions along shelf-slope topography bringing dense water to the surface. This reduces vertical density gradients leading to deeper wintertime convective overturn of surface waters, and an intensification of the AMOC.
Diathermal Heat Transport in a Global Ocean Model
Publisher: American Meteorological Society
Date: 2019
Abstract: The rate at which the ocean moves heat from the tropics toward the poles, and from the surface into the interior, depends on diabatic surface forcing and diffusive mixing. These diabatic processes can be isolated by analyzing heat transport in a temperature coordinate (the diathermal heat transport). This framework is applied to a global ocean sea ice model at two horizontal resolutions (1/4° and 1/10°) to evaluate the partioning of the diathermal heat transport between different mixing processes and their spatial and seasonal structure. The diathermal heat transport peaks around 22°C at 1.6 PW, similar to the peak meridional heat transport. Diffusive mixing transfers this heat from waters above 22°C, where surface forcing warms the tropical ocean, to temperatures below 22°C where midlatitude waters are cooled. In the control 1/4° simulation, half of the parameterized vertical mixing is achieved by background diffusion, to which sensitivity is explored. The remainder is associated with parameterizations for surface boundary layer, shear instability, and tidal mixing. Nearly half of the seasonal cycle in the peak vertical mixing heat flux is associated with shear instability in the tropical Pacific cold tongue, highlighting this region’s global importance. The framework presented also allows for quantification of numerical mixing associated with the model’s advection scheme. Numerical mixing has a substantial seasonal cycle and increases to compensate for reduced explicit vertical mixing. Finally, applied to Argo observations the diathermal framework reveals a heat content seasonal cycle consistent with the simulations. These results highlight the utility of the diathermal framework for understanding the role of diabatic processes in ocean circulation and climate.
Are ocean gyres driven by wind stress, surface buoyancy fluxes, or both?
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-14617
Abstract: The large-scale ocean circulation is fuelled by a combination of winds and buoyancy (or heat) fluxes acting on the ocean& #8217 s surface. Gyres are central features of large-scale ocean circulation and are involved in the transport of many tracers like heat, nutrients, carbon-dioxide and so on within and across ocean basins. Traditionally, the gyre circulation is explained by the relationship between meridional transport and wind stress curl, known as the Sverdrup balance. However, it has been proposed that surface buoyancy fluxes may also contribute to the formation of gyres, although such a theoretical relationship is lacking in oceanographic literature. Through a series of eddy-permitting global ocean model simulations, we aspire to better understand the relative contribution of wind stress and surface buoyancy fluxes on large-scale ocean circulation. We perturb the atmospheric forcing by spatially varying the wind stresses and/or surface buoyancy fluxes, while minimising the associated changes in mixed layer dynamics. We compare perturbed forcing simulations with a control simulation in an attempt to decompose the large- scale ocean circulation into buoyancy and wind-driven components.
The geography of numerical mixing in a suite of global ocean models
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-9319
Abstract: & & Numerical mixing, the physically spurious diffusion of tracers due to the numerical discretization of advection, is known to contribute to biases in ocean circulation models. However, quantifying numerical mixing is non-trivial, with most studies utilizing specifically targeted experiments in idealized settings. Here, we present a precise method based on water-mass transformation for quantifying numerical mixing, including its spatial structure, that can be applied to any conserved variable in global general circulation ocean models. The method is applied to a suite of global MOM5 ocean-sea ice model simulations with differing grid spacings and sub-grid scale parameterizations. In all configurations numerical mixing drives across-isotherm heat transport of comparable magnitude to that associated with explicitly-parameterized mixing. Numerical mixing is prominent at warm temperatures in the tropical thermocline, where it is sensitive to the vertical diffusivity and resolution. At colder temperatures, numerical mixing is sensitive to the presence of explicit neutral diffusion, suggesting that much of the numerical mixing in these regions acts as a proxy for neutral diffusion when it is explicitly absent. Comparison of equivalent (with respect to vertical resolution and explicit mixing parameters) 1/4-degree and 1/10-degree horizontal resolution configurations shows only a modest enhancement in numerical mixing at the eddy-permitting 1/4-degree resolution. Our results provide a detailed view of numerical mixing in ocean models and pave the way for future improvements in numerical methods.& &
Buoyant Gravity Currents Released from Tropical Instability Waves
Publisher: American Meteorological Society
Date: 02-2018
Abstract: Two extremely sharp fronts with changes in sea surface temperature .4°C over lateral distances of ~1 m were observed in the equatorial Pacific at 0°, 140°W and at 0.75°N, 110°W. In both cases, layers of relatively warm and fresh water extending to ~30-m depth propagated to the southwest as gravity currents. Turbulent kinetic energy dissipation rates averaging 4.5 × 10 −6 W kg −1 were measured with a microstructure profiler within the warm layer behind the leading edge of the fronts—1000 times greater than dissipation in the ambient water ahead of the fronts. From satellite images, these fronts were observed to propagate ahead of the trailing edge of a tropical instability wave (TIW) cold cusp. Results from an ocean model with 6-km grid resolution suggest that TIW fronts may release gravity currents through frontogenesis and loss of balance as the fronts approach the equator and the Coriolis parameter weakens. Sharp frontal features appear to be ubiquitous in the eastern tropical Pacific, have an influence on the distribution of biogeochemical tracers and organisms, and play a role in transferring energy out of the TIW field toward smaller scales and dissipation.
Related Organisations
University Of California Santa Barbara
Location: United States of America
Related Funding Activities
Building Australia’s Next-generation Ocean-sea Ice Model
Start Date: 2021
End Date: 2021
Funder: Australian Research Council
View Funded ActivityMixing And Air-sea Coupling In The Pacific: Toward Better El Nino Forecasts
Start Date: 2021
End Date: 2021
Funder: Australian Research Council
View Funded ActivityDiscovery Early Career Researcher Award - Grant ID: DE210100004
Start Date: 08-2021
End Date: 08-2025
Amount: $440,185.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP200100406
Start Date: 06-2021
End Date: 06-2025
Amount: $1,161,512.00
Funder: Australian Research Council
View Funded Activity