Lidar Measurements of Bora Wind Effects on Aerosol Loading

Lidar Measurements of Bora Wind Effects on Aerosol
Loading
Maruˇska Mole
University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica
Abstract
In the paper the analysis of wind measurements using two ultrasonic anemometers and a Mie-scattering lidar system is presented. Wind measurements with ultrasonic anemometers enabled a detailed analysis of wind
direction and wind gusts in Vipava valley in winter 2015. During the same
period the aerosol loading in the lower atmosphere was observed using a
lidar system with wavelength of 1064 nm. Both data sets were analyzed in
order to determine the correlation between wind speed and periodic structures appearing in some of the lidar measurements. The observed periodic
structures are believed to be the orographic / gravity waves induced by
the steep local orography. The influence of the wind on the height of planetary boundary layer was studied as well, focusing on the development of
planetary boundary layer during the episodes of Bora wind. The height
of well mixed lower level of atmosphere was used to obtain the depth of
atmosphere with the strong wind during those episodes.
Keywords: writting, LaTex, paper
Email address: maruska.mole@ung.si (Maruˇska Mole)
Preprint submitted to UNG Communication in Science
April 14, 2015
1. Introduction
1.1. Bora as a Downslope Wind
1.2. Planetary Boundary Layer
1.3. Gravity Waves
2. Instrumentation and Experimental Set-up
2.1. Mie-scattering Scanning Lidar
2.2. Bora Wind Measurements with Ultrasonic Anemometers
3. Lidar Observations During Bora Wind Outbreak
3.1. Variations of PBL Height During the Outbreak
3.2. Orographically Induced Waves Above PBL
4. Analysis of Wind and Aerosol Loading Properties
4.1. Periodicity of the Bora Wind
4.2. Correlation Between Wind Speed and Aerosol Loading at Different Heights
4.3. Periodicity of Induced Gravity Waves
5. Conclusions and Future Work
2
Characterization of silicon photomultipliers for use in
the Cherenkov Telescope Array
Gaˇsper Kukec Mezek
Laboratory for astroparticle physics, University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica
Abstract
In many physics applications, a measurement of an observable is performed
through detection of light with photodetectors. The most widely used photodetector in high energy physics is the photomultiplier tube (PMT), that
uses a photosensitive cathode to transform incident light into a measurable
signal through an electron avalanche. Due to their multiple electron acceleration stages they amplify the signal with a high gain and low signal noise,
which enables detection on the single photon level. However, due to their
large vacuum tube and photosensitive cathode, they are very sensitive to
mechanical shocks, can not be used in ambient light and are sensitive to
magnetic fields. Additionally, the voltage requirements to enable electron
avalanches inside the tube are very high (in the range of 1 kV 2 kV).
In recent years, a novel type of photodetectors is being developed that
exploits less demanding semiconductors, called silicon photomultipliers
(SiPM). In contrast to PMTs, they work through the production of electron–
hole pairs in the active area of a PN junction diode and as such require
voltages of under 100 V. One SiPM is constructed from many such diodes
(between 100 and 1000 per mm2 ) that collect the produced charge and then
sum it to output a signal. They can be used at ambient light, are mechanically robust, are insensitive to magnetic fields and produce a signal gain
and light sensitivity similar to that of PMTs. The most noticeable drawback
to SiPMs is a fairly high signal noise, resulting from thermally produced
electron–hole pairs, which can hide the true low level light signal.
In this paper, silicon photomultipliers are considered for high energy physics
use, most notably the Cherenkov Telescope Array (CTA), with description
and results of characterization measurements performed as part of the LabEmail address: gasper.kukec@ung.si (Gaˇsper Kukec Mezek)
Preprint submitted to UNG Communication in Science
April 14, 2015
oratory for astroparticle physics in University of Nova Gorica contribution
to the CTA collaboration.
Keywords:
References
2
Exposure of the Surface Detector of the Pierre
Auger Observatory to Gamma-Ray Bursts UHE
neutrino flux
Marta Trini
April 2015
Abstract
Atmospheric showers induced by ultra high energy neutrinos (UHE⌫s)
can be detected by the surface detector (SD) of the Pierre Auger Observatory. Neutrino induced showers selection, among the nucleonic induced
showers background, is based on young and inclined criteria. Gammaray bursts (GRBs) are supposed to produce large high energy neutrino
emission. In order to estimate the individual GRB neutrino flux limit the
calculation of the exposure of the SD array in function of neutrino energy
is necessary. In this paper we calculate exposure for single GRB, with
zenith angle between 75 and 90 deg, selected from GRBox catalog.
1
Reseach on Polarization Lidar System
Longlong Wang
April 2015
Abstract
The aerosols are closely related to the global climate changing and
environmental issues play an important role in the atmoshere and also in
many areas of scientific researching and application. Polarization lidar as
a Mie lidar, can distinguish the spatial distribution of shperical particales
and non-spherical particles in the atmosphere,which not only can obtain
the optical properties of atmosphere aerosol, but also makes up for the
lack of the observation of Mie lidar.the detection principle of polarization
lidar and the inversion method of depolarization ratio are briefly described
in the paper.
1
Contents
1 Introduction
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 State of the art in the field . . . . . . . . . . . . . . . . . . . . .
1.3 Purpose of the performed research . . . . . . . . . . . . . . . . .
3
3
3
3
2 The detection theory of polarization lidar
2.1 The basic detection principles of polarization lidar . . . . . . . .
3
3
3 Lidar systems
3.1 Lidar equation and inversion method . . . . . . . . . . . . . . . .
4
4
4 Analysis on designing of depolarization lidar system
4.1 Designing of depolarization lidar system . . . . . . . . . . . . . .
4.2 Characteristics of the depolarization lidar data traces . . . . . . .
6
6
6
5 Performance of the depolarization lidar
5.1 Calculation of signal to noise ratio . . . . . . . . . . . . . . . . .
5.2 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
6
6
6 Observations of atmosphere
6
7 Conclusion
6
2
1
1.1
Introduction
Motivation
Atmoshere aerosols means liquid or solid particles the diameter between 0.001100 µm suspended in the atmoshere. The main ingredients are mineral dust, sea
salt, fossil fuel residue, hydrocarbons, sulfate and nitrate particles. Aerosol particles of di↵erent shapes are generally divided into spherical and non-spherical
particles, reflecting di↵erent properties, which can be applied into e↵ectively
distinguishing the di↵erent type of aerosol particles. The continuous observation on aerosol depolarization ratio will contribute to the analysis of the climate
evolution and meanwhile, it is also significantly important in forecasting the
source of polluting aerosols. Understanding of the atmospheric aerosol radiation, climate, environment and other e↵ects, the study or aerosol physical and
optical properties of the atmoshere will be necessary, to bring great significance
of the detection of vertical resoluntion of atmospheric, to bring great significance
of the detection of the vertical resoluntion of atmospheric aerosols. Polarization
lidar is a post-e↵ective detection tool to detect the particle morphology of nonspherical particles using depolarization properties of sacttered Light. Because
Slovenia is located in the area of land-sea, often su↵ered from the African desert
and Bora wind which cause local weather problems. Therefore, the use of lidar
detect the characteristics of shape of particales during these weathers has great
significance for evolution of the climate reseach and prediction.
1.2
State of the art in the field
1.3
Purpose of the performed research
2
2.1
The detection theory of polarization lidar
The basic detection principles of polarization lidar
In the atmosphere, except for a few liquid particles presents a spherical, most
of the aerosol particles are non-spherical particles. Di↵erent shapes of particles
generated echo signals of backscatter having a di↵erent polarization properties, while the polarization lidar takes advantage of depolarization ratio of nonspherical particle is detected to study their optical and physical properties of
the atmosphere. When polarization lidar is being applied to probe atmospheric,
the schematic diagram of depolarization principle of aerosol particles contained
by atmosphere shown in Figure1:
Can be seen from Figure1, as sacttering particles are spherical and isotropic,
the backscatter is linearly polarization light based the on light sacttering theory
of particles, and the vibration direction of electric vector is identical of incident light. However, in the case of non-spherical scattering particales, even if
the incidet light is linearly polarized light, the light of backscatter generated
also trens to be partially polarized light, which is called the phenomenon of
depolarization.
Thus, on the condition of sacttering, as the emitting linearly polarization
laser, deduced from the intensity of light and characteristics of Polarization of
signal detected changing for morphological characteristics of the scattering par-
3
(a) The schematic diagram of spherical
particales depolarization.
(b) The schematic diagram of nonspherical particales depolarization.
Figure 1: The schematic diagram of spherical and non-spherical particales depolarization.
ticales, and the spatial distribution of the optical properties of the atmoshere
spherical and relative properties of non-sperical particles, such as the presence
of characteristics parameters. First, assume that the horizontal line for emitting a polarized light to the intensity of the atmosphere, the atmosphere after
the particle scattering, after the obtained forward scattered light will no longer
maintain the original linear polarization state, but only in the horizontal direction of polarization comprising light, its intensity, but also contains polarized
light in the vertical direction, its strength, wherein the component is the depolarization e↵ects from non-spherical particles. Thus, there is the vertical
component of the backward scattering intensity and the horizontal component
of the echo signal intensity. The ratio is defined as the linear depolarization
ratio, that is:
I1
=
(1)
I2
3
Lidar systems
we can see a funny distribution and in Figure 2 we see something else. The
lidar uses a frequency-tripled high power compact Q-Switched Nd:YAG pulsed
laser. Pulse energy at the wavelength of 355 nm and pulse width of 4 ns is 100
mJ. Pulse repetition frequency is 20 Hz. The receiver was constructed using
a parabolic mirror with a diameter of 800 mm and focal length of 410 mm.
The mirror is made of aluminum coated Pyrex and the coating is protected
with a thin layer of SiO2 . In order to make the lidar system steerable, both
the transmitter and the receiver are mounted on a common frame which can
slid horizontally in or out of the observatory build-ing. The zenith angle of the
entire frame is adjustable using a step motor with 0.1. angular resolution. In the
non-coaxial configuration of lidar system, the estimated complete overlap is from
1000 m, which should be considered in the application of vertical measurements.
3.1
Lidar equation and inversion method
we can see a funny distribution and in Figure ee something else. The lidar uses a
frequency-tripled high power compact Q-Switched Nd:YAG pulsed laser. Pulse
energy at the wavelength of 355 nm and pulse width of 4 ns is 100 mJ. Pulse
4
Figure 2: The configuration of the polarization lidar system
repetition frequency is 20 Hz. The receiver was constructed using a parabolic
mirror with a diameter of 800 mm and focal length of 410 mm. The mirror
is made of aluminum coated Pyrex and the coating is protected with a thin
layer of SiO2 . In order to make the lidar system steerable, both the transmitter
and the receiver are mounted on a common frame which can slid horizontally
in or out of the observatory build-ing. The zenith angle of the entire frame is
adjustable using a step motor with 0.1 angular resolution. In the non-coaxial
configuration of lidar system, the estimated complete overlap is from 1000 m,
which should be considered in the application of vertical measurements.
Z r
 p Pt
Pp = 2 p (r) exp[ 2
↵p (z)dz]
(2)
r
0
Z r
 s Pt
Ps = 2 s (r) exp[
(↵p (z) + ↵s (z))dz]
(3)
r
0
5
Figure 3: The structure of the PBS.
4
Analysis on designing of depolarization lidar
system
4.1
Designing of depolarization lidar system
4.2
Characteristics of the depolarization lidar data traces
5
Performance of the depolarization lidar
5.1
Calculation of signal to noise ratio
5.2
Conclusion
6
Observations of atmosphere
7
Conclusion
References
[1] http://www.treehouse-maps.com/, 12. 2. 2014.
ˇ
[2] Zagar,
M., Rakovec, J., 2007: Characteristics of the Bora wind under di↵erent
conditions of the lee background flow. 29th International Conference on Alpine
Meteorology ICAM 2007, Extended Abstracts, vol. 2, 309-312.
[3] Holton, J. R., 2004: An Introduction to Dynamic Meteorology, Fourth Edition.
Oxford: Elsevier Academic Press.
6
Simulation of micro-nozzle flows with the blob based
method of fundamental solutions
Rizwan Zahoor
University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica
1. Description
Understanding the fundamentals of liquid streams issued from micronozzles is vital for various applications in industry, technology and medicine
(e.g., combustion, agriculture, surface finish, drug delivery, atomic spectrometry etc.). The production of thin, long and stable fluid jets is necessary in every aerosol production process. They are steadily produced in the
laminar regime by injecting sufcient energy into the system to overcome the
resistance offered by the surface tension and viscosity. However, presently
little is known about how the nozzle geometry determines the jet stability.
The most commonly used numerical techniques to explore the solution of
the applied problem require considerable amount of human effort in terms
of mesh generation and calculation time.
Goals of the simulation are to predict the liquid jet shape (diameter,
length) and stability as a function of geometry, material properties and operating conditions, and to find a stable, long and thin jet with lowest possible flow rate.
In this Paper, A novel meshless technique for the solution of Stokes flow
using blob based Method of Fundamental Solution (MFS) will be explored.
Email address: rizwan.zahoor@ung.si (Rizwan Zahoor)
Preprint submitted to UNG Communication in Science
April 14, 2015
Simulation of Fluid Flow in Micro-Nozzles with the
Phase-Field Method
Nazia Talat
University of Nova Gorica, Vipavska 13, SI-5000 Nova Gorica
1. description
Two phase flow in micro channels has gained much attention because of
its wide applicability in modern science and technologies, such as MicroElectro-Mechanical Systems, micro heat exchangers and lab-on-a-chip in
medical and genetic engineering. For optimal design of such devices it
is important to understand the related flow. The behavior of fluid at the
micro-scale level is different from macro-scale level because the factors
such as surface tension, energy dissipation, and fluidic resistance start to
play an important role in the system. At macro-scale level most of the
systems are studied as a sharp- interface model where interface has zero
thickness. Each phase has its own physical properties (density, viscosity,
and concentration etc.) which are uniform with the occupied domain. As
phases are mixed, physical properties may change in a discontinuous way
across the interface. The behavior of such fluidic system can be described
by a set of mass, momentum, energy conservative equations, written for
each component. The solution of such models needs a set of boundary conditions at the interface which are complicated and can give oscillatory behavior during solution procedure. In literature, the methods to predict the
interface between two phase can be classified into two groups: interface
capturing method ( volume of fluid method, level set method) interface
tracking method ( marker and cell , front tracking). At micro-scale level
interface tracking problem can be described by using diffuse interface. In
phase field method interface has a non-zero thickness with various physical
properties like surface tension etc. In phase field method there is no need
of boundary conditions explicitly on the interface and one single equation
Email address: nazia.talat@ung.si (Nazia Talat)
Preprint submitted to UNG Communication in Science
Scope of the paper
April 14, 2015
can be described for the entire system.
2
Implementation of a Quasi-Upwind Scheme in the
Simulation of a Rectangular Cavity
Vanja Hatiˇc
Institute of Metals and Technology, Lepi pot 13, SI-1000 Ljubljana
Abstract
A low frequency electromagnetic casting simulator (LFEMC) was developed on the Institute of Metals and Technology. The LFEMC simulator allows the user to simulate the direct chill casting of aluminium alloys under
the influence of electromagnetic filed. Due to the instability of the results a
new diffraction method of the convection term is sought. A simplified case
of upwind scheme is proposed in the paper. The method is further tested
on a benchmark case of a rectangular cavity.
Keywords: Upwind Scheme, casting simulation, Cavity, electromagnetic
casting
1. Introduction
2. Main text
References
[1] C. Hirsch, Numerical Computation of Internal and External Flows: The
Fundamentals of Computational Fluid Dynamics, Second Edition, 2nd
Edition, Butterworth-Heinemann, Oxford; Burlington, MA, 2007.
[2] S. Patankar, Numerical Heat Transfer and Fluid Flow, 1st Edition, CRC
Press, New York, 1980.
[3] T. Sophy, H. Sadat, On the Numerical Solution of Unsteady Fluid Flow
Problems by a Meshless Method, Revue Europenne des lments 11 (7-8)
(2002) 989–1004. doi:10.3166/reef.11.989-1004.
URL http://www.tandfonline.com/doi/abs/10.3166/reef.11.989-1004
Email address: vanja.hatic@imt.si (Vanja Hatiˇc)
Preprint submitted to UNG Communication in Science
April 14, 2015
ˇ
[4] R. Vertnik, B. Sarler,
Solution of a continuous casting of steel benchmark test by a meshless method, Engineering Analysis with Boundary
Elements 45. doi:10.1016/j.enganabound.2014.01.017.
[5] H. Lin, S. Atluri, The Meshless Local Petrov-Galerkin (MLPG) method
for solving incompressible Navier-Stokes equations, CMES - Computer
Modeling in Engineering and Sciences 2 (2) (2001) 117–142.
2
Modeling coupled thermoelasticity: a comparison of
two meshless approaches.
Boˇstjan Mavriˇc
Institute of Metals and Technology, Lepi pot 11, SI-1000 Ljubljana
Abstract
Something abstract.
Keywords: local radial basis function collocation method, local
Petrov-Galerkin method, meshless methods, kriging, collocation,
thermomechanics
1. Introduction
• Literature review
• Our prev. work
• Any other comparisons of meshless methods? (For mechanics or in
general.)
• Describe which method the results are compared with [1]
2. Governing equations
• Write down the governing equation
• Introduce dimensionless quantities
• Describe problem geometry & boundary conditions
Email address: bostjan.mavric@imt.si (Boˇstjan Mavriˇc)
Preprint submitted to UNG Communication in Science
April 9, 2015
3. Method formulation
3.1. Domain discretization & sub-domain generation
3.2. Construction of local interpolants
3.3. Application to differential operators
4. Results
Provide plots for temperature, axial displacement and stress for the following cases:
4.1. Thermal shock
4.2. Pressure shock
4.3. Thermal and pressure shock in combination.
5. Conclusions
• Our method is the best.
Acknowledgments
Thanks to mr. Hui from Siegen and authors of [1] for their data used in
comparisons. Thanks for funding from ARRS, YR program.
[1] B.-J. Zheng, X.-W. Gao, K. Yang, Chuan-Zeng, A novel meshless local
Petrov-Galerkin method for dynamic coupled thermoelasticity analysis under thermal and mechanical shock loading, Engineering Analysis
with Boundary Elements.
2
SUSTAINABILITY EVALUATION OF DIFFRENT DOMESTIC WASTE COLLECTING APPROACHES
I would like to write about waste management and one of its stages - waste collecon.
Waste has a large impact on the environment. Using the words of Dražen Šimleša, the author of
"Ecological footprint - how development crushed sustainability", we have created a civilizaon of
waste. It is important that we learn to create as less as possible waste or if that is inevitably, to learn
how to reduce it and dispose it in a proper way - recycling and waste separaon.
I am going to propose a new, e&cient model which is going to bring lower consumpon of energy and
lower costs in waste management. It is known, that waste management has a some kind of a life cycle
- one can't go without the other, and in other words said, one has an impact to another.
We live in a world, where informaon travels fast - it is very clear that people can be educated, not
just through schools, but in other ways, how to build and live a sustainable life.
SLAVICA SCHUSTER