scholarly journals Multifractal analysis of radar rainfall fields over the area of Rome

2005 ◽  
Vol 2 ◽  
pp. 293-299 ◽  
Author(s):  
G. Calenda ◽  
E. Gorgucci ◽  
F. Napolitano ◽  
A. Novella ◽  
E. Volpi
Keyword(s):  
Scale Invariance ◽  
Large Scale ◽  
Doppler Radar ◽  
Risk Mitigation ◽  
Small Scale ◽  
Radar Rainfall ◽  
Invariance Properties ◽  
Meteorological Radar ◽  
Using Data ◽  
Precipitation Events

Abstract. A scale-invariance analysis of space and time rainfall events monitored by meteorological radar over the area of Rome (Italy) is proposed. The study of the scale-invariance properties of intense precipitation storms, particularly important in flood forecast and risk mitigation, allows to transfer rainfall information from the large scale predictive meteorological models to the small scale hydrological rainfall-runoff models. Precipitation events are monitored using data collected by the polarimetric Doppler radar Polar 55C (ISAC-CNR), located 15 km Southeast from downtown. The meteorological radar provides the estimates of rainfall intensity over an area of about 10 000 km2 at a resolution of 2×2 km2 in space and 5 min in time. Many precipitation events have been observed from autumn 2001 up to now. A scale-invariance analysis is performed on some of these events with the aim at exploring the multifractal properties and at understanding their dependence on the meteorological large-scale conditions.

Student Perceptions of Community: A Different Perspective

NASPA Journal ◽  
1998 ◽  
Vol 35 (4) ◽  
Author(s):  
Jackie Clark ◽  
Joan Hirt
Keyword(s):  
Student Perceptions ◽  
Large Scale ◽  
Research University ◽  
Small Scale ◽  
Social Environments ◽  
Common Assumption ◽  
Small Communities ◽  
Public Research University ◽  
The Common ◽  
Using Data

The creation of small communities has been proposed as a way of enhancing the educational experience of students at large institutions. Using data from a survey of students living in large and small residences at a public research university, this study does not support the common assumption that small-scale social environments are more conducive to positive community life than large-scale social environments.

scholarly journals Ionospheric response to magnetar flare: signature of SGR J1550–5418 on coherent ionospheric Doppler radar

2017 ◽  
Vol 35 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Ayman Mahrous
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Doppler Radar ◽  
Ionospheric Disturbance ◽  
Eastern Mediterranean ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Perturbations ◽  
Onset Phase

Abstract. This paper presents observational evidence of frequent ionospheric perturbations caused by the magnetar flare of the source SGR J1550–5418, which took place on 22 January 2009. These ionospheric perturbations are observed in the relative change of the total electron content (ΔTEC/Δt) measurements from the coherent ionospheric Doppler radar (CIDR). The CIDR system makes high-precision measurements of the total electron content (TEC) change along ray-paths from ground receivers to low Earth-orbiting (LEO) beacon spacecraft. These measurements can be integrated along the orbital track of the beacon satellite to construct the relative spatial, not temporal, TEC profiles that are useful for determining the large-scale plasma distribution. The observed spatial TEC changes reveal many interesting features of the magnetar signatures in the ionosphere. The onset phase of the magnetar flare was during the CIDR's nighttime satellite passage. The nighttime small-scale perturbations detected by CIDR, with ΔTEC/Δt  ≥  0.05 TECU s−1, over the eastern Mediterranean on 22 January 2009 were synchronized with the onset phase of the magnetar flare and consistent with the emission of hundreds of bursts detected from the source. The maximum daytime large-scale perturbation measured by CIDR over northern Africa and the eastern Mediterranean was detected after ∼ 6 h from the main phase of the magnetar flare, with ΔTEC/Δt  ≤  0.10 TECU s−1. These ionospheric perturbations resembled an unusual poleward traveling ionospheric disturbance (TID) caused by the extraterrestrial source. The TID's estimated virtual velocity is 385.8 m s−1, with ΔTEC/Δt  ≤  0.10 TECU s−1.

scholarly journals Collective dynamics of bursty particle precipitation initiating in the inner and outer plasma sheet

2009 ◽  
Vol 27 (2) ◽  
pp. 745-753 ◽  
Author(s):  
V. M. Uritsky ◽  
E. Donovan ◽  
A. J. Klimas ◽  
E. Spanswick
Keyword(s):  
Electron Emission ◽  
Plasma Sheet ◽  
Large Scale ◽  
Probability Distributions ◽  
Spatiotemporal Analysis ◽  
Auroral Oval ◽  
Small Scale ◽  
Low Latitude ◽  
Dissipation Mechanism ◽  
Precipitation Events

Abstract. Using multiscale spatiotemporal analysis of bursty precipitation events in the nighttime aurora as seen by the POLAR UVI instrument, we report a set of new statistical signatures of high- and low-latitude auroral activity, signaling a strongly non-uniform distribution of dissipation mechanism in the plasma sheet. We show that small-scale electron emission events that initiate in the equatorward portion of the nighttime auroral oval (scaling mode A1) have systematically steeper power-law slopes of energy, power, area, and lifetime probability distributions compared to the events that initiate at higher latitudes (mode B). The low-latitude group of events also contain a small but energetically important subpopulation of substorm-scale disturbances (mode A2) described by anomalously low distribution exponents characteristic of barely stable thermodynamic systems that are prone to large-scale sporadic reorganization. The high latitude events (mode

Estimation of Elasticities of Substitution for CES Production Functions using Data on Selected Manufacturing Industries in Pakistan

1987 ◽  
Vol 26 (2) ◽  
pp. 161-178 ◽  
Author(s):  
George E. Battese ◽  
Sohail J. Malik
Keyword(s):  
Large Scale ◽  
Weighted Least Squares ◽  
Manufacturing Industries ◽  
Policy Implications ◽  
Production Functions ◽  
Small Scale ◽  
Least Squares Regression ◽  
Firm Level ◽  
Using Data ◽  
Asset Size

Firm-level stochastic CES production functions are specified for large and Small-scale firms in twelve manufacturing industries in Pakistan. Assuming that firms within specified asset-size categories for which aggregative data are available have the same levels of productive inputs, the elasticities of substitution of labour for capital are estimated, using weighted least-squares regression. For large-scale firms, the estimated elasticities are generally not significantly different from one, whereas for small-scale firms the elasticities are significantly smaller than one but greater than zero. These results indicate that there may exist more possibilities for the substitution of labour for capital in manufacturing industries in Pakistan than were claimed by earlier researchers. This finding has important policy implications for Pakistan's economic development.

scholarly journals Sensitivity of Heavy Precipitation Forecasts to Small Modifications of Large-Scale Weather Patterns for the Elbe River

2010 ◽  
Vol 11 (3) ◽  
pp. 770-780 ◽  
Author(s):  
Ingo Schlüter ◽  
Gerd Schädler
Keyword(s):  
Extreme Precipitation ◽  
Large Scale ◽  
Spatiotemporal Variability ◽  
Small Scale ◽  
Synoptic Situation ◽  
Flood Events ◽  
Weather Patterns ◽  
Extreme Precipitation Events ◽  
The Impact ◽  
Precipitation Events

Abstract Extreme flood events are caused by long-lasting and/or intensive precipitation. The detailed knowledge of the distribution, intensity, and spatiotemporal variability of precipitation is, therefore, a prerequisite for hydrological flood modeling and flood risk management. For hydrological modeling, temporal and spatial high-resolution precipitation data can be provided by meteorological models. This study deals with the question of how small changes in the synoptic situation affect the characteristics of extreme forecasts. For that purpose, two historic extreme precipitation events were hindcasted using the Consortium for Small Scale Modeling (COSMO) model of the German Weather Service (DWD) with different grid resolutions (28, 7, and 2.8 km), where the domains with finer resolutions were nested into the ones with coarser resolution. The results show that the model is capable of simulating such extreme precipitation events in a satisfactory way. To assess the impact of small changes in the synoptic situations on extreme precipitation events, the large-scale atmospheric fields were shifted to north, south, east, and west with respect to the orography by about 28 and 56 km, respectively, in one series of runs while in another series, the relative humidity and temperature were increased to modify the amount of precipitable water. Both series were performed for the Elbe flood events in August 2002 and January 2003, corresponding to two very different synoptic situations. The results show that the modeled precipitation can be quite sensitive to small changes of the synoptic situation with changes in the order of 20% for the maximum daily precipitation and that the types of synoptic situations play an important role. While van Bebber weather conditions, of Mediterranean origin, were quite sensitive to modifications, more homogeneous weather patterns were less sensitive.

scholarly journals Sharia Maqashid Index as a measuring performance of Islamic banking: A more holistic approach

2017 ◽  
Vol 14 (2) ◽  
pp. 193-201
Author(s):  
Sri Hartono ◽  
Agus Sobari
Keyword(s):  
Financial Performance ◽  
Commercial Banks ◽  
Large Scale ◽  
Banking System ◽  
Holistic Approach ◽  
Performance Comparison ◽  
Small Scale ◽  
Islamic Banking ◽  
Due Measure ◽  
Using Data

So far, measurements of financial performance of Islamic banking is still predominantly still used by indicators of financial performance of conventional banking system. Its implication, many stakeholders, especially customers of Islamic banks. For Moslems are difficulty in measuring the benefits of the existence of Islamic banking. It is clearly due measure of success of Islamic banking course will be very different from conventional banking successes. If the benchmarks used today is still conventional, the consequences will be contained incorrect results of performance comparison of Islamic banking and conventional banking. Thus, both of the banking system becomes irrelevant and less apt to be compared directly. The size of Islamic banking performance should not directly benchmarking with conventional banking. It must be linked to the objectives and the establishment of Islamic banking noble intentions, namely to provide human well simultaneously implement the principles contained in sharia maqashid. This research will try to practice the measurement of financial performance based Sharia Maqashid and use it to make comparisons between the performance of the national largest-scale of Islamic commercial banks and regional small-scale of Islamic rural banks (BPR Syariah). This study presented using data from the financial statements of the three Islamic commercial banks and three Islamic rural banks (BPR Syariah). The results showed that the performance of the national largest-scale of Islamic commercial banks and regional small-scale of Islamic rural banks (BPR Syariah), all of them, has no a Sharia Maqashid index whose high value. This shows the inconsistency, that should be, the national largest-scale of Islamic banking to always focus on the muamalah objectives according by sharia. From the comparison of financial performance based on sharia maqashid, it turns out the national large-scale of Islamic commercial banks tend to have a lower index of Sharia Maqashid than the regional small-scale of Islamic rural banks (BPR Syariah).

scholarly journals Finescale Structure of the T–S Relation in the Eastern North Atlantic

2005 ◽  
Vol 35 (8) ◽  
pp. 1437-1454 ◽  
Author(s):  
R. Ferrari ◽  
K. L. Polzin
Keyword(s):  
North Atlantic ◽  
Large Scale ◽  
Salinity Gradient ◽  
Mesoscale Eddies ◽  
Thermal Dissipation ◽  
Small Scale ◽  
The North ◽  
Wide Range ◽  
Using Data ◽  
Gyre Circulation

Abstract Distributions of temperature (T) and salinity (S) and their relationship in the oceans are the result of a balance between T–S variability generated at the surface by air–sea fluxes and its removal by molecular dissipation. In this paper the role of different motions in setting the cascade of T–S variance to dissipation scales is quantified using data from the North Atlantic Tracer Release Experiment (NATRE). The NATRE observational programs include fine- and microscale measurements and provide a snapshot of T–S variability across a wide range of scales from basin to molecular. It is found that microscale turbulence controls the rate of thermal dissipation in the thermocline. At this level the T–S relation is established through a balance between large-scale advection by the gyre circulation and small-scale turbulence. Further down, at the level of intermediate and Mediterranean waters, mesoscale eddies are the rate-controlling process. The transition between the two regimes is related to the presence of a strong salinity gradient along density surfaces associated with the outflow of Mediterranean waters. Mesoscale eddies stir this gradient and produce a rich filamentation and salinity-compensated temperature inversions: isopycnal stirring and diapycnal mixing are both required to explain the T–S relation at depth.

scholarly journals Cirrus Mammatus Properties Derived from an Extended Remote Sensing Dataset

2006 ◽  
Vol 63 (2) ◽  
pp. 712-725 ◽  
Author(s):  
Likun Wang ◽  
Kenneth Sassen
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
Doppler Radar ◽  
Three Dimensional ◽  
Remote Sensing Data ◽  
Cloud Base ◽  
Doppler Velocity ◽  
Small Scale ◽  
Length Scales ◽  
Atmospheric Remote Sensing

Abstract The first quantitative and statistical evaluation of cirrus mammatus clouds based on wavelet analysis of remote sensing data is made by analyzing the University of Utah Facility for Atmospheric Remote Sensing (FARS) 10-yr high-cloud dataset. First, a case study of cirrus mammata combining a high-resolution lidar system and a W-band Doppler radar is presented, yielding an assessment of the thermodynamic environment and dynamic mechanisms. Then, 25 cirrus mammatus cases selected from the FARS lidar dataset are used to disclose their characteristic environmental conditions, and vertical and length scales. The results show that cirrus mammata occur in the transition zone from moist (cloudy) to dry air layers with weak wind shear, which suggests that cloud-induced thermal structures play a key role in their formation. Their maximum vertical and horizontal length scales vary from 0.3 to 1.1 km and 0.5 to 8.0 km, respectively. It is also found that small-scale structures develop between the large-scale protuberances. The spectral slopes of the lidar-returned power and mean radar Doppler velocity data extracted from the cirrus cloud-base region further indicate the presence of developed three-dimensional, locally isotropic, homogeneous turbulence generated by buoyancy. Finally, comparisons of anvil and cirrus mammata are made. Although both are generated in a similar environment, cirrus mammata generally do not form fallout fronts like their anvil counterparts, and so do not have their smooth and beautiful outlines.

scholarly journals Evaluation and Intercomparison of High-Resolution Satellite Precipitation Estimates—GPM, TRMM, and CMORPH in the Tianshan Mountain Area

2018 ◽  
Vol 10 (10) ◽  
pp. 1543 ◽  
Author(s):  
Chi Zhang ◽  
Xi Chen ◽  
Hua Shao ◽  
Shuying Chen ◽  
Tong Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Tianshan Mountains ◽  
Small Scale ◽  
Tianshan Mountain ◽  
Precipitation Pattern ◽  
Precipitation Gradient ◽  
Ecological Research ◽  
Satellite Precipitation ◽  
Precipitation Events

With high resolution and wide coverage, satellite precipitation products like Global Precipitation Measurement (GPM) could support hydrological/ecological research in the Tianshan Mountains, where the spatial heterogeneity of precipitation is high, but where rain gauges are sparse and unevenly distributed. Based on observations from 46 stations from 2014–2015, we evaluated the accuracies of three satellite precipitation products: GPM, Tropical Rainfall Measurement Mission (TRMM) 3B42, and the Climate Prediction Center morphing technique (CMORPH), in the Tianshan Mountains. The satellite estimates significantly correlated with the observations. They showed a northwest–southeast precipitation gradient that reflected the effects of large-scale circulations and a characteristic seasonal precipitation gradient that matched the observed regional precipitation pattern. With the highest correlation (R = 0.51), the lowest error (RMSE = 0.85 mm/day), and the smallest bias (1.27%), GPM outperformed TRMM and CMORPH in estimating daily precipitation. It performed the best at both regional and sub-regional scales and in low and mid-elevations. GPM had relatively balanced performances across all seasons, while CMORPH had significant biases in summer (46.43%) and winter (−22.93%), and TRMM performed extremely poorly in spring (R = 0.31; RMSE = 1.15 mm/day; bias = −20.29%). GPM also performed the best in detecting precipitation events, especially light and moderate precipitation, possibly due to the newly added Ka-band and high-frequency microwave channels. It successfully detected 62.09% of the precipitation events that exceeded 0.5 mm/day. However, its ability to estimate severe rainfall has not been improved as expected. Like other satellite products, GPM had the highest RMSE and bias in summer, suggesting limitations in its way of representing small-scale precipitation systems and isolated deep convection. It also underestimated the precipitation in high-elevation regions by 16%, suggesting the difficulties of capturing the orographic enhancement of rainfall associated with cap clouds and feeder–seeder cloud interactions over ridges. These findings suggest that GPM may outperform its predecessors in the mid-/high-latitude dryland, but not the tropical mountainous areas. With the advantage of high resolution and improved accuracy, the GPM creates new opportunities for understanding the precipitation pattern across the complex terrains of the Tianshan Mountains, and it could improve hydrological/ecological research in the area.

Twenty-five years of botanical epidemiology

1988 ◽  
Vol 321 (1207) ◽  
pp. 377-387 ◽  
Keyword(s):  
Large Scale ◽  
Small Scale ◽  
Two Dimensional ◽  
Logistic Equations ◽  
Botanical Epidemiology ◽  
Simulation Techniques ◽  
The Family ◽  
Using Data ◽  
Contact Distribution ◽  
Models Of Disease

Epidemiological models in plant pathology usually belong to the family of logistic equations, describing the increase in disease intensity with time. Expansion and refinement are possible by applying dynamic simulation techniques on digital computers. Among these are models of disease increase in time and two-dimensional (horizontal) space, and spore dispersal in and over a crop in two-dimensional (vertical) space. Recently, an analytical model was developed by Van den Bosch and co-workers to describe focus expansion in time and two-dimensional (horizontal) space as a function of three biological parameters that were relatively easy to measure: gross reproduction, time kernel, and contact distribution. The model was tested using data from previous experiments not designed for this purpose and from a new experiment specifically designed for validation. The model treats focus expansion as a process with a constant radial velocity and seems valid on a small scale of a few metres and, after rescaling, on a large scale of hundreds of kilometres.

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