scholarly journals Rescaled Statistics and Wavelet Analysis on Agricultural Drought Disaster Periodic Fluctuations in China from 1950 to 2016

2018 ◽  
Vol 10 (9) ◽  
pp. 3257 ◽  
Author(s):  
Qian Wang ◽  
Yangyang Liu ◽  
Linjing Tong ◽  
Weihong Zhou ◽  
Xiaoyu Li ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Time Scale ◽  
Large Scale ◽  
Periodic Variation ◽  
Agricultural Drought ◽  
Small Scale ◽  
Multiple Time ◽  
Disaster Area ◽  
Period 2 ◽  
Drought Disaster

An agricultural drought disaster was analyzed with the new insight of rescaled statistics (R/S) and wavelet analysis in this study. The results showed that: (1) the Hurst index of the agricultural disaster area, the inundated area of agricultural drought disaster, and the grain loss was 0.821, 0.874, and 0.953, respectively, indicating that the process of the agricultural drought disaster had stronger positive continuity during the study period; (2) based on the Morlet analysis of the agricultural disaster area, the inundated area of the agricultural drought disaster, and the grain loss of China from 1950 to 2016, the time series of the agricultural drought had multiple time scale features with the periodic variation on a large scale containing the periodic variation on a small scale; and (3) in the last 67 years, the strong wavelet energy spectrum of the agricultural disaster area, the inundated area of the agricultural drought disaster, and the grain loss was at the time scale of ≈22–32 years, ≈24–32 years, and ≈25–32 years, respectively. In addition, the first major period in the agricultural drought disaster area, the inundated area of agricultural drought disaster, and the grain loss had average periods of approximately 16 years, 16 years, and 18 years, respectively.

scholarly journals MaBμlS-2: high-precision microlensing modelling for the large-scale survey era

2020 ◽  
Vol 498 (2) ◽  
pp. 2196-2218
Author(s):  
David Specht ◽  
Eamonn Kerins ◽  
Supachai Awiphan ◽  
Annie C Robin
Keyword(s):  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Near Infrared ◽  
Event Rate ◽  
Structural Features ◽  
Small Scale ◽  
Stellar Kinematics ◽  
Full Account ◽  
Space Telescope

ABSTRACT Galactic microlensing datasets now comprise in excess of 104 events and, with the advent of next-generation microlensing surveys that may be undertaken with facilities such as the Rubin Observatory (formerly LSST) and Roman Space Telescope (formerly WFIRST), this number will increase significantly. So too will the fraction of events with measurable higher order information, such as finite-source effects and lens–source relative proper motion. Analysing such data requires a more sophisticated Galactic microlens modelling approach. We present a new second-generation Manchester–Besançon Microlensing Simulator (MaBμlS-2), which uses a version of the Besançon population synthesis Galactic model that provides good agreement with stellar kinematics observed by the Hubble Space Telescope (HST) towards the bulge. MaBμlS-2 provides high-fidelity signal-to-noise limited maps of the microlensing optical depth, rate and average time-scale towards a 400 deg2 region of the Galactic bulge in several optical to near-infrared pass-bands. The maps take full account of the unresolved stellar background, as well as limb-darkened source profiles. Comparing MaBμlS-2 with the efficiency-corrected OGLE-IV 8000 event sample shows a much improved agreement over the previous version of MaBμlS and succeeds in matching even small-scale structural features in the OGLE-IV event rate map. However, evidence remains for a small underprediction of the event rate per source and overprediction of the time-scale. MaBμlS-2 is available online (www.mabuls.net, Specht & Kerins) to provide on-the-fly maps for user-supplied cuts in survey magnitude, event time-scale and relative proper motion.

scholarly journals A severe blizzard event in Romania – a case study

2009 ◽  
Vol 9 (2) ◽  
pp. 623-634 ◽  
Author(s):  
F. Georgescu ◽  
S. Tascu ◽  
M. Caian ◽  
D. Banciu
Keyword(s):  
Numerical Simulations ◽  
Time Scale ◽  
Large Scale ◽  
Forecast Accuracy ◽  
Horizontal Resolution ◽  
Maximum Temperature ◽  
Small Scale ◽  
Relative Role ◽  
Snow Layer ◽  
Strong Winds

Abstract. During winter cold strong winds associated with snowfalls are not unusual for South and Southeastern Romania. The episode of 2–4 January 2008 was less usual due to its intensity and persistence. It happened after a long period (autumn 2006–autumn 2007) of mainly southerly circulations inducing warm weather, when the absolute record of the maximum temperature was registered. The important snowfalls and snowdrifts, leading to a consistent snow layer (up to 100 cm), produced serious transport and electricity supply perturbations. Since this atypical local weather event was not correctly represented by the operational numerical forecasts, several cross-comparison numerical simulations were performed to analyze the relative role of the coupler/coupling models and to compare two ways of process-scale uncertainties mitigation: optimizing the forecast range and performing ensemble forecast through the perturbation of the lateral boundary conditions. The results underline, for this case, the importance of physical parametrization package on the first place and secondary, the importance of the model horizontal resolution. The resolution increase is beneficial only in the local process representation; on larger scale it may either improve or decrease the accuracy effect, depending on the specified nudging between large-scale and small-scale information. The event capture is likely to be favored by two elements: a more appropriate time-scale of the event's physics and the quality of the transmitted large-scale information. Concerning the time scale, the statistics on skill as a function of forecast range are shown to be a useful tool in order to increase the accuracy of the numerical simulations. Ensembles forecasting versus resolution increase experiments indicate, for such atypical events, an interesting supply in the forecast accuracy through the ensemble method when applied to correct the minimum skill of the deterministic forecast.

The growth of meteorological disturbances

1949 ◽  
Vol 45 (1) ◽  
pp. 92-98 ◽  
Author(s):  
H. Bondi
Keyword(s):  
Heat Conduction ◽  
Temperature Gradient ◽  
Lower Limit ◽  
Time Scale ◽  
Large Scale ◽  
Ideal Gas ◽  
Small Scale ◽  
Sharp Distinction ◽  
The Subject ◽  
The Stability

1. Introduction. A considerable amount of attention has been paid to the problem of determining the conditions which decide whether a liquid heated from below is stable or unstable. The motion consequent upon the disturbance of an unstable ideal gas does not, however, seem to have been treated so far, and this problem forms the subject of the present paper. Heat conduction and viscosity are at first neglected, and we are therefore dealing with the small motions of a gas slightly disturbed from a position of equilibrium under the influence of gravity. The condition for the stability of such a gas is well known, namely, the temperature gradient must be less than the adiabatic gradient. Furthermore, it is known that there is a sharp distinction between slow large-scale (meteorological) and rapidly varying small-scale (acoustical) phenomena. The present paper confirms these points and derives the time scale of meteorological phenomena. Heat conduction and viscosity are then shown to set a lower limit to the dimensions of such disturbances, while the effect of the earth's rotation is shown to be negligible.

scholarly journals PORTFOLIO ROBUSTNESS EVALUATION: A CASE STUDY IN THE ELECTRICITY SECTOR

2015 ◽  
Vol 23 (1) ◽  
pp. 59-80 ◽  
Author(s):  
João Carlos LOURENÇO ◽  
João Oliveira SOARES ◽  
Carlos A. BANA E COSTA
Keyword(s):  
Large Scale ◽  
Evaluation Model ◽  
Electricity Sector ◽  
Small Scale ◽  
Multiple Time ◽  
Electricity Distribution ◽  
Different Types ◽  
Distribution Company ◽  
Multicriteria Decision Support

Managers continually face the task of allocating resources to projects when there is not enough money to fund them all. Portfolio Robustness Evaluation (PROBE) is a multicriteria decision support system developed to help managers to perform that difficult task. This paper presents a PROBE model, developed for an electricity distribution company, to select the best portfolio of projects, subject to budget constraints for different types of projects and various organisational units in multiple time periods. Projects requiring large-scale investments are analysed separately from the small-scale projects. The robustness of the selected portfolio of large-scale projects is analysed in an iterative process where broader uncertainty ranges are considered for the values of the projects, and also when an environmental impact criterion is added to the evaluation model.

scholarly journals The photocycle of orange carotenoid protein conceals distinct intermediates and asynchronous changes in the carotenoid and protein components

2017 ◽  
Author(s):  
E.G. Maksimov ◽  
N.N. Sluchanko ◽  
Y.B. Slonimskiy ◽  
A.V. Stepanov ◽  
E.A. Shirshin ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Intermediate State ◽  
Time Scale ◽  
Large Scale ◽  
Photosynthetic Apparatus ◽  
Water Soluble ◽  
Small Scale ◽  
Orange Carotenoid Protein ◽  
Protein Components ◽  
Structural Methods

AbstractThe 35 kDa water-soluble Orange Carotenoid Protein (OCP) is responsible for photoprotection in cyanobacteria. It acts as a light intensity sensor that simultaneously serves as efficient quencher of phycobilisome excitation energy as well as of reactive oxygen species. Photoactivation triggers large-scale conformational rearrangements to convert OCP from the orange OCPO state to the red active signaling state OCPR, as demonstrated by various structural methods. Eventually, such rearrangements imply complete yet reversible separation of structural domains (C- and N-terminal domain) and significant translocation of the carotenoid cofactor. Very recently, dynamic crystallography of OCPO crystals suggested the existence of photocycle intermediates with small-scale rearrangements that may trigger further transitions in the protein. However, the currently existing gap between the ultra-fast picosecond and 100 millisecond time scale of spectroscopic and structural data precludes knowledge about distinct intermediate states. In this study, we took advantage of single 7 ns laser pulses to study carotenoid absorption transients in OCP on the time-scale from 100 ns to 10 s, which allowed us to detect a red intermediate state preceding the red signaling state OCPR. In addition, time-resolved fluorescence spectroscopy and following assignment of carotenoid-induced quenching of different tryptophan residues revealed a novel orange intermediate state, which appears during back-relaxation of photoactivated OCPR to OCPO. Our results show asynchronous changes in the carotenoid and protein components and provide refined mechanistic information about the OCP photocycle as well as introduce new kinetic signatures for future studies of OCP photoactivity and photoprotection.Significance statementCyanobacteria utilize the Orange Carotenoid Protein (OCP) to protect their photosynthetic apparatus from the harmful effects of intense sunlight. OCP is a blue light-triggered photoswitch, which undergoes photoconversion from its dark adapted orange to the active red state, the latter being able to interact with the phycobilisome antennae and quench their fluorescence, thus avoiding excessive energy flow to the photosystems. With the help of the fluorescence recovery protein (FRP), OCP detaches from phycobilisomes and can return faster into the orange state. Until now, only the thermodynamically stable orange state and the metastable red state are established in a primitive photocycle. In this work, we apply transient absorption and fluorescence spectroscopy and identify two novel photocycle intermediates of physiological relevance.

scholarly journals A multiscale dynamo model driven by quasi-geostrophic convection

2015 ◽  
Vol 780 ◽  
pp. 143-166 ◽  
Author(s):  
Michael A. Calkins ◽  
Keith Julien ◽  
Steven M. Tobias ◽  
Jonathan M. Aurnou
Keyword(s):  
Prandtl Number ◽  
Viscous Dissipation ◽  
Time Scale ◽  
Large Scale ◽  
Force Balance ◽  
Dynamo Model ◽  
Small Scale ◽  
Ohmic Dissipation ◽  
Evolution Time ◽  
Magnetic Prandtl Number

A convection-driven multiscale dynamo model is developed in the limit of low Rossby number for the plane layer geometry in which the gravity and rotation vectors are aligned. The small-scale fluctuating dynamics are described by a magnetically modified quasi-geostrophic equation set, and the large-scale mean dynamics are governed by a diagnostic thermal wind balance. The model utilizes three time scales that respectively characterize the convective time scale, the large-scale magnetic evolution time scale and the large-scale thermal evolution time scale. Distinct equations are derived for the cases of order one and low magnetic Prandtl number. It is shown that the low magnetic Prandtl number model is characterized by a magnetic to kinetic energy ratio that is asymptotically large, with ohmic dissipation dominating viscous dissipation on the large scale. For the order one magnetic Prandtl number model, the magnetic and kinetic energies are equipartitioned and both ohmic and viscous dissipation are weak on the large scales; large-scale ohmic dissipation occurs in thin magnetic boundary layers adjacent to the horizontal boundaries. For both magnetic Prandtl number cases the Elsasser number is small since the Lorentz force does not enter the leading order force balance. The new models can be considered fully nonlinear, generalized versions of the dynamo model originally developed by Childress & Soward (Phys. Rev. Lett., vol. 29, 1972, pp. 837–839), and provide a new theoretical framework for understanding the dynamics of convection-driven dynamos in regimes that are only just becoming accessible to direct numerical simulations.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale

Development of Physics Learning Module Based on Guided Inquiry with Light Wave Material in Class XI of Senior High School

2020 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Evi Rahmawati ◽  
Irnin Agustina Dwi Astuti ◽  
N Nurhayati
Keyword(s):  
Large Scale ◽  
Learning Strategy ◽  
Student Response ◽  
Average Score ◽  
Small Scale ◽  
Design Development ◽  
Teacher Response ◽  
Student Responses ◽  
Analysis Design ◽  
Scientific Skills

IPA Integrated is a place for students to study themselves and the surrounding environment applied in daily life. Integrated IPA Learning provides a direct experience to students through the use and development of scientific skills and attitudes. The importance of integrated IPA requires to pack learning well, integrated IPA integration with the preparation of modules combined with learning strategy can maximize the learning process in school. In SMP 209 Jakarta, the value of the integrated IPA is obtained from 34 students there are 10 students completed and 24 students are not complete because they get the value below the KKM of 68. This research is a development study with the development model of ADDIE (Analysis, Design, Development, Implementation, and Evaluation). The use of KPS-based integrated IPA modules (Science Process sSkills) on the theme of rainbow phenomenon obtained by media expert validation results with an average score of 84.38%, average material expert 82.18%, average linguist 75.37%. So the average of all aspects obtained by 80.55% is worth using and tested to students. The results of the teacher response obtained 88.69% value with excellent criteria. Student responses on a small scale acquired an average score of 85.19% with highly agreed criteria and on the large-scale student response gained a yield of 86.44% with very agreed criteria. So the module can be concluded receiving a good response by the teacher and students.

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