High altitude stations are often emphasized as free tropospheric measuring sites but they remain influenced by atmospheric boundary layer (ABL) air masses due to convective transport processes. The ...local and meso-scale topographical features around the station are involved in the convective boundary layer development and in the formation of thermally induced winds leading to ABL air lifting. The station altitude alone is not a sufficient parameter to characterize the ABL influence. In this study, a topography analysis is performed allowing calculation of a newly defined index called ABL-TopoIndex. The ABL-TopoIndex is constructed in order to correlate with the ABL influence at the high altitude stations and long-term aerosol time series are used to assess its validity. Topography data from the global digital elevation model GTopo30 were used to calculate five parameters for 43 high and 3 middle altitude stations situated on five continents. The geometric mean of these five parameters determines a topography based index called ABL-TopoIndex, which can be used to rank the high altitude stations as a function of the ABL influence. To construct the ABL-TopoIndex, we rely on the criteria that the ABL influence will be low if the station is one of the highest points in the mountainous massif, if there is a large altitude difference between the station and the valleys or high plains, if the slopes around the station are steep, and finally if the inverse drainage basin potentially reflecting the source area for thermally lifted pollutants to reach the site is small. All stations on volcanic islands exhibit a low ABL-TopoIndex, whereas stations in the Himalayas and the Tibetan Plateau have high ABL-TopoIndex values. Spearman's rank correlation between aerosol optical properties and number concentration from 28 stations and the ABL-TopoIndex, the altitude and the latitude are used to validate this topographical approach. Statistically significant (SS) correlations are found between the 5th and 50th percentiles of all aerosol parameters and the ABL-TopoIndex, whereas no SS correlation is found with the station altitude. The diurnal cycles of aerosol parameters seem to be best explained by the station latitude although a SS correlation is found between the amplitude of the diurnal cycles of the absorption coefficient and the ABL-TopoIndex.
This study reveals the effect of aerosols and water vapor on downward longwave radiation in the high mountain region of Musala peak, Bulgaria. The investigated period is 01/01/2017 (Jan. 1st 2017) - ...30/09/2019 (Sep. 30th 2019). Statistical methods are the main tool for discovering the relationships between the different elements. The results indicate that air temperature is the leading factor for downward longwave radiation, specific humidity, and amount of aerosols in the air. That is why, in order to reveal the pure relationship between downward longwave radiation, specific humidity and amount of aerosols in the atmosphere, the air temperature was cleared from the data series. After this procedure, the results show that specific humidity has a significant influence on the downward longwave radiation flux, and an increase of 1% of the specific humidity results in an increase of about 12-15% in the values of the downward longwave radiation. At air temperatures around 0ºC the influence of water vapor on the downward longwave flux is highest, which is due to the phase transitions of the water - a process during which release/absorption of radiation in the longwave spectrum occurs. The amount of aerosols in the atmosphere also has a significant effect on this type of radiation, and an increase of 1% of the amount of aerosols in the air at air temperatures above -5.5°C results in an increase of the downward longwave radiation of about 2-4%. The findings of this study show that coarser and opaque aerosol particles have a stronger effect on downward longwave radiation. In the area of Musala peak, as the air temperature rises, there is an increase in the amount of aerosols in the air, a decrease in their size, and a transition from transparent to opaque aerosols. The combination of these different tendencies causes the influence of aerosols on downward longwave radiation to be strongest in the middle temperature interval - air temperatures between -5.5°C and +5.5°C. Due to the increased total amount of aerosols and increased amount of opaque aerosols, their influence on downward longwave radiation is significant also at air temperatures above 5.5°C.
The aim of this study is to reveal the direct radiative effect of aerosols on global solar shortwave radiation in the region of peak Musala, which has specific climatic and environmental conditions. ...Correlations between the measured global solar shortwave radiation and the total aerosol content, Ångström exponent in the visible spectrum, absorption of radiation by aerosols, scattering of radiation by aerosols, Single Scattering Albedo (SSA) of aerosols are calculated using statistical methods. The results show that the underlying surface through its albedo plays a significant role in terms of the radiative effect of aerosols. At low albedo values, the higher aerosol amounts exert, at surface level, a negative radiative effect and vice versa. However, at high albedo values, the higher aerosol amounts exert, at surface level, a positive radiative effect and vice versa. This is due to the fact that a higher albedo leads to larger amounts of reflected and scattered shortwave radiation, especially close to the earth's surface, which at higher aerosol amounts result in an increase in the amount of scattered shortwave radiation, which also increases the global solar shortwave radiation. The relationships between global solar shortwave radiation and aerosols are, in most cases, non-linear, which is due to the statistical distributions of the studied parameters, which are not normal. Disclosed dependencies should be taken into account when modeling the impact of aerosols on climate change.
•Surface albedo plays a significant role in terms of radiative effect of aerosols.•High albedo leads to a positive radiative effect of aerosols at surface level.•Higher albedo causes larger amounts of reflected and scattered shortwave radiation.•DRE of aerosols at peak Musala changes its sign at albedo values of about 0.4
The article examines the practice of Bulgarian courts regarding the determination of jurisdiction over matters relating to relationships in rem between spouses. The provision of the Bulgarian Private ...International Law Code (Article 8 of the Code) provides that under the terms established by Article 7, the Bulgarian courts shall have jurisdiction over matters relating to relationships in personam and in rem between spouses. Article 7 of the
Code provides that matrimonial matters shall be cognizable in the Bulgarian courts if one of the spouses is a Bulgarian national or is habitually resident in the Republic of Bulgaria.
This article is dedicated to the problem of the agreement on choice of applicable law in matters of relationships in rem between spouses. A short survey of the legislation of the EU member states, as ...well as some non EU member states, is made. The provision of the Bulgarian Private International Law Code provides that spouses may select an applicable law to govern the relationships in rem there between. The choice of applicable law must be evidenced in writing, dated and signed by the spouses. The entry into and the validity of the agreement on choice shall be governed by the selected law. The choice may be made before or after entry into the marriage. The spousesmay change or revoke the choice of applicable law.
The adoption of European legislation on matrimonial property regimes is among the priorities of the Еuropean Union. There are two international conventions of the Hague Conference on Private ...International Law relevant to this issue, namely the Convention of 17 July 1905 on conflict of laws relating to the effects of marriage on the rights and duties of spouses in their personal relationships and with regard to their estates, and the Convention of 14 March 1978 on the law applicable to matrimonial property regimes.
The paper presents an analytical method for calculating the initial velocity and flight distance of a reusable training-practice mortar round for short distance firing intended as a simulator for ...mortar teams. This is the first stage in the overall development of the simulator and the results obtained will be used to determine the elements of the mortar’s internal ballistics. The paper also presents a simulation model developed with MATLAB software program, with which calculations were made for 60 mm, 82 mm and 120 mm training-practice mortars.
The paper investigates the capabilities for increased productivity, reduced lead times, and higher product quality with the concerted use of CAD/CAM/CAE and software platforms for workgroups. For the ...purposes of this report, the design of the reusable training-practice mortar round for short distance firing is used as an example.
The temporal variations of cosmic-ray intensity, measured by ground-based detectors at various latitudes, longitudes, and altitudes, are related to the geophysical and solar phenomena. The latter are ...interplanetary coronal mass ejections and fast solar wind from coronal holes, which cause interplanetary magnetic field (IMF) abrupt variations near Earth. Interacting with the magnetosphere, they cause worldwide sudden decreases (Forbush decreases, FDs) of intensity followed by gradual recovery. The amplitude of the flux depletion depends on the type and energy of the registered particle, which in turn depends on geographical coordinates and the detector's energy threshold and selective power. SEVAN particle detector network with nodes in Europe and Armenia selects three types of particles that demonstrate coherent depletion and recovery and correspond to different energy galactic protons interacting with disturbed magnetospheric plasmas.
On November 3–4, 2021, an interplanetary coronal mass injection (ICME) hit the magnetosphere, sparking a strong G3-class geomagnetic storm and auroras as far south as California and New Mexico. All detectors of the SEVAN network have registered an (FD) of ≈5% depletion in a 1-min time series of count rates. Approaching the maximum solar activity cycle, large variations of the particle flux intensity were registered on February 27, March 23, 2023, and March 24, 2024.
In this work, we present measurements of these FDs performed on mountain altitudes on Aragats (Armenia), Lomnicky Stit (Slovakia), Mileshovka (Czechia), and at sea level DESY (Hamburg, Germany). We compared FD measurements made by SEVAN detectors and neutron monitors located on Aragats and Lomnicky Stit and made a correlation analysis of FD registration at different locations.
•Low energy CR, neutrons, and high energy muons measured by SEVAN detector are sensitive to solar modulation.•SEVAN and NM detectors demonstrate coherent depletion and recovery of cosmic ray fluxes.•SEVAN detectors at mountain altitudes registered a pre-FD increase in fluxes of high-energy muons.•FD coincides with large values of the interplanetary magnetic field B, and small values of geomagnetic field Bx.•SEVAN measurements confirm that FD depends highly on the disturbed IMF rather than its Bz component.
A gamma-spectrometer with a NaI detector and a suitable lead collimator directed to the sky was put in operation at Moussala BEO at an altitude of 2925 m above sea level. The gamma-rays spectrum in ...the 150-6500 keV energy interval was measured at two-hour intervals. In many cases, significant fluctuations were observed in the .sup.222Rn lines intensity. Fluctuations of the gamma-rays intensity in the 2800-6400 keV energy interval were also observed. These gamma-rays originate from the interaction of various cosmic rays with Earth's atmosphere. The device's stability was controlled through the intensity of the 1460 keV gamma-line of the .sup.40K background.Key words: Moussala, gamma-rays, NaI, detector, fluctuations, atmosphere
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