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Combined measurments of water vapor over Vipava Valley, Slovenia
Andreja Sušnik, Tingyao He, Fei Gao, Klemen Bergant, Samo Stanič, Darko Veberič, 2013, published scientific conference contribution abstract

Found in: osebi
Keywords: atmosferska fizika, vodna para, Mie lidar, GPS, radiosonde
Published: 22.01.2015; Views: 2810; Downloads: 69
URL Fulltext (0,00 KB)

Lidar observations of atmospheric boundary layer dynamics and aerosol loading in urban environments
Andreja Sušnik, Tingyao He, Fei Gao, Klemen Bergant, Samo Stanič, 2013, published scientific conference contribution abstract

Found in: osebi
Keywords: atmosferska fizika, atmosferska mejna plast, aerosoli, radiosonde
Published: 22.01.2015; Views: 2677; Downloads: 84
URL Fulltext (0,00 KB)

Center za raziskave atmosfere
2014, radio or television broadcast

Found in: osebi
Keywords: ozračje, aerosoli, burja
Published: 22.01.2015; Views: 2710; Downloads: 14
URL Fulltext (0,00 KB)

Študij atmosferskih procesov v Vipavski dolini na podlagi razširjanja aerosolov
Marko Vučković, Janja Vaupotič, Griša Močnik, Samo Stanič, Luka Drinovec, Klemen Bergant, Asta Gregorič, Longlong Wang, Maruška Mole, 2016, published scientific conference contribution

Abstract: Vipavska dolina je geomorfološko dokaj zaprta, kar po eni strani omogoča pojav močne burje, po drugi strani pa ob stabilnih meteoroloških razmererah ugodne pogoje za kopičenje aerosolov znotraj prizemne mejne plasti. Poznavanje dinamike višinske porazdelitve aerosolov s sočasno uporabo prizemnih meritev omogoča raziskave lokalnih emisij aerosolov, transporta aerosolov na daljše razdalje ter značilnih atmosferskih struktur, ki se pojavijo v različnih vremenskih pogojih. Pri meritvah smo uporabili metode daljinskega zaznavanja z lidarjem, ki omogočajo opazovanje časovnega in prostorskega spreminjanja koncentracij aerosolov, ter točkovne meritve, ki omogočajo njihovo prepoznavanje in določanje njihovih lastnosti. Ugotovili smo, da je mogoče lidarske meritve uporabiti za študij vrste atmosferskih procesov in struktur v zelo različnih vremenskih pogojih. Opazili smo manjše konvekcijske strukture znotraj prizemne mejne plasti in gravitacijske valove nad njo. Meritve vsebnosti in lastnosti aerosolov pri tleh kažejo, da se lahko ob stabilnih atmosferskih pogojih v primerih povečanja lokalnih emisij njihove koncentracije hitro povečajo. Dinamiko in strukturo razširjanja aerosolov znotraj Vipavske doline bomo v prihodnje podrobneje raziskali s sočasnim prostorskim pregledovanjem z metodami daljinskega zaznavanja.
Found in: osebi
Keywords: aerosoli, atmosferski procesi, daljinsko zaznavanje, Vipavska dolina
Published: 25.01.2016; Views: 3060; Downloads: 9
.pdf Fulltext (4,02 MB)

Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Darko Veberič, Marta Trini, Samo Stanič, Ahmed Saleh, Gašper Kukec Mezek, Andrej Filipčič, A. Aab, 2016, original scientific article

Abstract: The azimuthal asymmetry in the risetime of signals in Auger surface detector stations is a source of information on shower development. The azimuthal asymmetry is due to a combination of the longitudinal evolution of the shower and geometrical effects related to the angles of incidence of the particles into the detectors. The magnitude of the effect depends upon the zenith angle and state of development of the shower and thus provides a novel observable, (secθ)max, sensitive to the mass composition of cosmic rays above 3×1018  eV. By comparing measurements with predictions from shower simulations, we find for both of our adopted models of hadronic physics (QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass increases slowly with energy, as has been inferred from other studies. However, the mass estimates are dependent on the shower model and on the range of distance from the shower core selected. Thus the method has uncovered further deficiencies in our understanding of shower modeling that must be resolved before the mass composition can be inferred from (secθ)max.
Found in: osebi
Keywords: ultra-high energy cosmic rays (UHECR), UHECR mass composition, Pierre Auger Observatory, extensive air showers, Auger Surface Detector signals risetime, azimuthal symmetry
Published: 15.04.2016; Views: 2414; Downloads: 0
.pdf Fulltext (698,19 KB)

Observations of atmospheric structures in the Vipava valley based on Lidar data
Klemen Bergant, William Eichinger, Samo Stanič, Asta Gregorič, Longlong Wang, Maruška Mole, Marko Vučković, 2016, published scientific conference contribution abstract

Found in: osebi
Keywords: lidar, atmosferske strukture, vremenske razmere
Published: 03.05.2016; Views: 2247; Downloads: 0
.pdf Fulltext (33,19 KB)

Evolution of the planetary boundary layer in the presence of fog and plume
Maruška Mole, Marko Vučković, Klemen Bergant, Asta Gregorič, Samo Stanič, Longlong Wang, 2016, published scientific conference contribution abstract

Found in: osebi
Keywords: lidar, vodna para, sipanje, GPS
Published: 03.05.2016; Views: 2467; Downloads: 1
.pdf Fulltext (35,71 KB)

Measurements and modeling of air mass motion in the troposphere
Miha Živec, 2016, undergraduate thesis

Abstract: Throughout the history human race depended on weather, so one of the priorities for its survival was to understand weather patterns and to be able to forecast weather. With the development of powerful computers, atmospheric numerical methods and precision instruments for atmospheric monitoring, it is possible to predict weather with greater accuracy and for a longer period of time ahead. At the same time, we are able to gain improved understanding of physical processes that occur in the atmosphere and represent one of most important features in our world. This diploma thesis focuses on the lowest part of the atmosphere - troposphere only, as all weather occurs in the troposphere. Weather is a complete collection of momentary thermodynamic states in the atmosphere and is defined with thermodynamic variables and relations between them. The goal of this thesis is development and presentation of a new way to determine the direction and speed of air mass movement, based on the combination of passive and active remote sensing techniques. A lidar is being used to determine the range to an object, in our case a cloud, that can be used as a tracer in the air current. Simultaneously with lidar ranging of clouds that same clouds are being visually monitored in a series of optical photographs. Selecting and following the temporal evolution of distinct cloud features and their range allows us to calculate the speed of clouds. The performance of this method was tested on four cases in Feb. and Mar. 2016. Measurements were performed in Ajdovščina in different weather conditions. Along with remote sensing (infra-red lidar and optical cameras), ground measurements of wind at Ajdovščina were performed. Wind speeds and directions obtained from remote sensing were compared to atmospheric sounding data from Ljubljana and Udine at similar heights and performed within as small as possible time window. In all four cases remote sensing results for wind speeds and directions agree relatively well with atmospheric sounding. Deviations are expected to be primarily due to spatial and temporal mismatch between sounding and remote sensing measurements. Another source of uncertainties are the limitations of the present remote sensing method in the determination of the actual direction of the wind, however, theses limitations could be eliminated in the future by using an all-sky camera and vertical lidar configuration.
Found in: osebi
Keywords: remote sensing, wind, atmosphere
Published: 13.10.2016; Views: 3919; Downloads: 108
.pdf Fulltext (9,48 MB)

Study of the properties of air flow over orographic barrier
Maruška Mole, 2017, doctoral dissertation

Abstract: Earth’s atmosphere is a complex system. All weather phenomena take place in its lowest layer, the troposphere, which is strongly influenced by human activities and the underlying surface orography. A good example of the influence the orography has on the behavior of air flows is the appearance of strong north-east downslope wind in Vipava valley, called Bora. Numerical models used to analyze flows in complex terrain need meteorological data both for setting the initial conditions and the verification of modeling results. Obtaining spatial distributions of meteorological observables can be challenging, especially in the case of strong winds, such as Bora, where traditional methods may be inadequate due to prohibitive wind speeds. In most cases, vertical properties of the atmosphere can be obtained using remote sensing techniques. Contrary to vertical profile measurements with traditional methods, remote sensing techniques do not require the measuring device to be placed within the flow and are therefore more appropriate for measurements in severe weather conditions such as strong winds. The aim of this thesis is a detailed analysis of wind and tropospheric structure properties in and above the Vipava valley in a variety of typical atmospheric conditions, including strong wind events. It employs a combination of high resolution wind and lidar data in addition to standard meteorological measurements. In Ajdovščina, there are four predominant wind directions, two of them directly connected to Bora. In the case of Bora, periodicity analysis of wind data from Ajdovščina yielded a range of possible wind gust periods between 1 and 7 minutes. The periods were not stable, with the periodogram less noisy for stable wind directions. Wavelike structures were found to be present in the troposphere in half of the investigated cases, regardless of the presence of Bora. In statically stable conditions, gravity waves propagated throughout the planetary boundary layer (PBL). In the case of Bora, the PBL experienced oscillations with periods between 1 and 2 minutes. A shear layer was present above the PBL, causing Kelvin-Helmholtz waves at its boundaries with periods ranging from 3 to 6 minutes. In some cases, periodic structures were observed above the shear layer as well, which were found to have longer periods than those within the PBL.
Found in: osebi
Keywords: remote sensing, Vipava valley, wind properties, Bora, wind gusts, wind periodicity, tropospheric structures, Kelvin-Helmholtz waves
Published: 18.09.2017; Views: 2624; Downloads: 73
.pdf Fulltext (45,11 MB)

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