Impacts of initial conditions and model configuration on simulations of polar lows near Svalbard using Polar WRF with 3DVAR

2021 ◽  
Author(s):  
Jianjun Xue ◽  
David H. Bromwich ◽  
Ziniu Xiao ◽  
Lesheng Bai
Keyword(s):  
Initial Conditions ◽  
Polar Lows ◽  
Model Configuration

scholarly journals CAFE60v1: A 60-year large ensemble climate reanalysis. Part I: System design, model configuration and data assimilation.

2021 ◽  
pp. 1-48
Author(s):  
Terence J. OߣKane ◽  
Paul A. Sandery ◽  
Vassili Kitsios ◽  
Pavel Sakov ◽  
Matthew A. Chamberlain ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Sea Ice ◽  
System Design ◽  
Retrospective Analysis ◽  
Initial Conditions ◽  
Design Model ◽  
Large Ensemble ◽  
Strongly Coupled ◽  
Model Configuration ◽  
Coupled Data Assimilation

AbstractWe detail the system design, model configuration and data assimilation evaluation for the CSIRO Climate retrospective Analysis and Forecast Ensemble system: version 1. CAFE60v1 has been designed with the intention of simultaneously generating both initial conditions for multi-year climate forecasts and a large ensemble retrospective analysis of the global climate system from 1960 to present. Strongly coupled data assimilation (SCDA) is implemented via an ensemble transform Kalman filter in order to constrain a general circulation climate model to observations. Satellite (altimetry, sea surface temperature, sea ice concentration) and in-situ ocean temperature and salinity profiles are directly assimilated each month, whereas atmospheric observations are sub-sampled from the JRA-55 atmospheric reanalysis. Strong coupling is implemented via explicit cross domain covariances between ocean, atmosphere, sea ice and ocean biogeochemistry. Atmospheric and surface ocean fields are available at daily resolution and monthly resolution for the land, subsurface ocean and sea ice. The system produces 96 climate trajectories (state estimates) over the most recent six decades as well as a complete data archive of initial conditions potentially enabling individual forecasts for all members each month over the 60 year period. The size of the ensemble and application of strongly coupled data assimilation lead to new insights for future reanalyses.

scholarly journals The Marine Virtual Laboratory (version 2.1): enabling efficient ocean model configuration

2016 ◽  
Vol 9 (9) ◽  
pp. 3297-3307
Author(s):  
Peter R. Oke ◽  
Roger Proctor ◽  
Uwe Rosebrock ◽  
Richard Brinkman ◽  
Madeleine L. Cahill ◽  
...  
Keyword(s):  
General Circulation ◽  
Initial Conditions ◽  
Scientific Research ◽  
Ocean Model ◽  
Virtual Laboratory ◽  
Time Space ◽  
Starting Point ◽  
Model Configuration ◽  
Regional Ocean Model ◽  
Ocean General Circulation

Abstract. The technical steps involved in configuring a regional ocean model are analogous for all community models. All require the generation of a model grid, preparation and interpolation of topography, initial conditions, and forcing fields. Each task in configuring a regional ocean model is straightforward – but the process of downloading and reformatting data can be time-consuming. For an experienced modeller, the configuration of a new model domain can take as little as a few hours – but for an inexperienced modeller, it can take much longer. In pursuit of technical efficiency, the Australian ocean modelling community has developed the Web-based MARine Virtual Laboratory (WebMARVL). WebMARVL allows a user to quickly and easily configure an ocean general circulation or wave model through a simple interface, reducing the time to configure a regional model to a few minutes. Through WebMARVL, a user is prompted to define the basic options needed for a model configuration, including the model, run duration, spatial extent, and input data. Once all aspects of the configuration are selected, a series of data extraction, reprocessing, and repackaging services are run, and a “take-away bundle” is prepared for download. Building on the capabilities developed under Australia's Integrated Marine Observing System, WebMARVL also extracts all of the available observations for the chosen time–space domain. The user is able to download the take-away bundle and use it to run the model of his or her choice. Models supported by WebMARVL include three community ocean general circulation models and two community wave models. The model configuration from the take-away bundle is intended to be a starting point for scientific research. The user may subsequently refine the details of the model set-up to improve the model performance for the given application. In this study, WebMARVL is described along with a series of results from test cases comparing WebMARVL-configured models to observations and manually configured models. It is shown that the automatically configured model configurations produce a good starting point for scientific research.

Ensemble decadal predictions from analysed initial conditions

2007 ◽  
Vol 365 (1857) ◽  
pp. 2179-2191 ◽  
Author(s):  
Alberto Troccoli ◽  
T.N Palmer
Keyword(s):  
Time Scales ◽  
Initial Conditions ◽  
Coupled Model ◽  
Seasonal Prediction ◽  
Model Configuration ◽  
Global Cooling ◽  
The Impact ◽  
Climatic Signals ◽  
Different Levels ◽  
Initialization Procedure

Sensitivity experiments using a coupled model initialized from analysed atmospheric and oceanic observations are used to investigate the potential for interannual-to-decadal predictability. The potential for extending seasonal predictions to longer time scales is explored using the same coupled model configuration and initialization procedure as used for seasonal prediction. It is found that, despite model drift, climatic signals on interannual-to-decadal time scales appear to be detectable. Two climatic states have been chosen: one starting in 1965, i.e. ahead of a period of global cooling, and the other in 1994, ahead of a period of global warming. The impact of initial conditions and of the different levels of greenhouse gases are isolated in order to gain insights into the source of predictability.

scholarly journals The Marine Virtual Laboratory: enabling efficient ocean model configuration

2015 ◽  
Vol 8 (11) ◽  
pp. 9741-9768
Author(s):  
P. R. Oke ◽  
R. Proctor ◽  
U. Rosebrock ◽  
R. Brinkman ◽  
M. L. Cahill ◽  
...  
Keyword(s):  
General Circulation ◽  
Initial Conditions ◽  
Scientific Research ◽  
Ocean Model ◽  
Virtual Laboratory ◽  
Time Space ◽  
Starting Point ◽  
Model Configuration ◽  
Regional Ocean Model ◽  
Ocean General Circulation

Abstract. The technical steps involved in configuring a regional ocean model are analogous for all community models. All require the generation of a model grid, preparation and interpolation of topography, initial conditions, and forcing fields. Each task in configuring a regional ocean model is straight-forward – but the process of downloading and reformatting data can be time-consuming. For an experienced modeller, the configuration of a new model domain can take as little as a few hours – but for an inexperienced modeller, it can take much longer. In pursuit of technical efficiency, the Australian ocean modelling community has developed the Web-based MARine Virtual Laboratory (WebMARVL). WebMARVL allows a user to quickly and easily configure an ocean general circulation or wave model through a simple interface, reducing the time to configure a regional model to a few minutes. Through WebMARVL, a user is prompted to define the basic options needed for a model configuration, including the: model, run duration, spatial extent, and input data. Once all aspects of the configuration are selected, a series of data extraction, reprocessing, and repackaging services are run, and a "take-away bundle" is prepared for download. Building on the capabilities developed under Australia's Integrated Marine Observing System, WebMARVL also extracts all of the available observations for the chosen time-space domain. The user is able to download the take-away bundle, and use it to run the model of their choice. Models supported by WebMARVL include three community ocean general circulation models, and two community wave models. The model configuration from the take-away bundle is intended to be a starting point for scientific research. The user may subsequently refine the details of the model set-up to improve the model performance for the given application. In this study, WebMARVL is described along with a series of results from test cases comparing WebMARVL-configured models to observations and manually-configured models. It is shown that the automatically-configured model configurations produce a good starting point for scientific research.

Sebuah Generalisasi Baru Barisan Fibonacci-Lucas

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Musraini M Musraini M ◽  
Rustam Efendi ◽  
Rolan Pane ◽  
Endang Lily
Keyword(s):  
Recurrence Relation ◽  
Initial Conditions ◽  
Lucas Sequence ◽  
Binet’S Formula

Barisan Fibonacci dan Lucas telah digeneralisasi dalam banyak cara, beberapa dengan mempertahankan kondisi awal, dan lainnya dengan mempertahankan relasi rekurensi. Makalah ini menyajikan sebuah generalisasi baru barisan Fibonacci-Lucas yang didefinisikan oleh relasi rekurensi B_n=B_(n-1)+B_(n-2),n≥2 , B_0=2b,B_1=s dengan b dan s bilangan bulat  tak negatif. Selanjutnya, beberapa identitas dihasilkan dan diturunkan menggunakan formula Binet dan metode sederhana lainnya. Juga dibahas beberapa identitas dalam bentuk determinan.   The Fibonacci and Lucas sequence has been generalized in many ways, some by preserving the initial conditions, and others by preserving the recurrence relation. In this paper, a new generalization of Fibonacci-Lucas sequence is introduced and defined by the recurrence relation B_n=B_(n-1)+B_(n-2),n≥2, with ,  B_0=2b,B_1=s                          where b and s are non negative integers. Further, some identities are generated and derived by Binet’s formula and other simple methods. Also some determinant identities are discussed.

Meningkatkan Kemampuan Guru dalam Menerapkan Model Pembelajaran Problem Centered Learning Melalui Focus Group Discission di Sekolah Dasar Negeri 187/X Bangun Karya Tahun 2019/2020

2020 ◽  
Vol 10 (1) ◽  
pp. 86
Author(s):  
Mujiem Mujiem
Keyword(s):  
Elementary School ◽  
Action Research ◽  
Focus Group ◽  
Initial Conditions ◽  
Learning Model ◽  
Class Action ◽  
Learning Activities ◽  
Implementation Phase ◽  
The Subject ◽  
Academic Year

This research is a classroom action research that aims to improve the ability of teachers to apply the problem centered learning model of learning in the Elementary School 187/ X Bangun Karya, Academic Year 2019/2020. The subject of this study was a teacher at 187 / X Bangun Karya Elementary School, Rantau Rasau District, Tanjung Jabung Timur District, Jambi Province. This class action research was carried out in two cycles, each cycle consisting of two meetings. The results of the evaluation are converted into a recapitulation table of the results of cycle I. The conversion results state that the research has not yet reached the target, it needs to be continued with cycle II. The results of observers in the implementation phase of the second cycle showed that all parts of the learning activities were going well, so that there were no more parts of the learning activities that needed to be improved. While the results of the second cycle are converted with the results of the recapitulation table states that the study has reached the target limit of completeness criteria in the first cycle that is equal to 50% and an average of 68.7 in the initial conditions of improvement in the second cycle completeness criteria to be 100% and the average namely 91.7 states that the Focus Group Discission can improve the ability of teachers to apply the Problem Centered Learning learning model in learning in 187 / X Public Elementary School Build Work Year 2019/2020.

Dynamics of the macromolecular composition of the biomass of microalgae in the morning under natural light. Model

2020 ◽  
pp. 45-52
Author(s):  
Alexander S. Lelekov ◽  
Anton V. Shiryaev
Keyword(s):  
Biochemical Composition ◽  
Initial Conditions ◽  
Natural Light ◽  
Photoautotrophic Growth ◽  
Structural Part ◽  
Basic Model ◽  
Microalgae Culture ◽  
Simulation Results ◽  
Structural Parts ◽  
Macromolecular Composition

The work is devoted to modeling the growth of optically dense microalgae cultures in natural light. The basic model is based on the idea of the two-stage photoautotrophic growth of microalgae. It is shown that the increase in the intensity of sunlight in the first half of the day can be described by a linear equation. Analytical equations for the growth of biomass of microalgae and its macromolecular components are obtained. As the initial conditions, it is assumed that at the time of sunrise, the concentration of reserve biomass compounds is zero. The simulation results show that after sunrise, the growth of the microalgae culture is due only to an increase in the reserve part of the biomass, while the structural part practically does not change over six hours. Changes in the ratio of the reserve and structural parts of the biomass indicate a change in the biochemical composition of cells.

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