Todor Arsov

BEO Moussala – A New Facility for Complex Environment Studies

The main areas of research at the Basic Environmental Observatory (BEO) Moussala, Rila Mountain, are the aerospace and terrestrial environment. The interactions between cosmic rays and Earth atmosphere, global change parameters and climate research, natural hazards and technological risks are the objectives of the investigations. Real-time measurements of basic parameters of space and atmosphere are carried out. The information is transmitted via a high frequency radio-telecommunication system to the Internet and is stored in a database for further analysis within GAW, EURDEP, EUSAAR and UNBSS international programmes. Ecotoxicological investigations are performed to study the mountain ecosystems. On-line data and detailed information about BEO Moussala are available at: http://beo-db.inrne.bas.bg

BEO Moussala: Complex for Environmental Studies

The main areas of research at the Basic Environmental Observatory (BEO) Moussala, Rila Mountain, are the aerospace and terrestrial environment. The interactions between cosmic rays and the Earth’s atmosphere, global change parameters and climate research, and natural hazards and technological risks are the objectives of the investigations.

Aerosol and gamma background measurements at Basic Environmental Observatory Moussala

Abstract Trans boundary and local pollution, global climate changes and cosmic rays are the main areas of research performed at the regional Global Atmospheric Watch (GAW) station Moussala BEO (2925 m a.s.l., 42°10’45’’ N, 23°35’07’’ E). Real time measurements and observations are performed in the field of atmospheric chemistry and physics. Complex information about the aerosol is obtained by using a threewavelength integrating Nephelometer for measuring the scattering and backscattering coefficients, a continuous light absorption photometer and a scanning mobile particle sizer. The system for measuring radioactivity and heavy metals in aerosols allows us to monitor a large scale radioactive aerosol transport. The measurements of the gamma background and the gamma-rays spectrum in the air near Moussala peak are carried out in real time. The HYSPLIT back trajectory model is used to determine the origin of the data registered. DREAM code calculations [2] are used to forecast the air mass trajectory. The information obtained combined with a full set of corresponding meteorological parameters is transmitted via a high frequency radio telecommunication system to the Internet.

Some connections between aerosols, atmospheric transport, and relative humidity at peak Musala

Some connections between aerosols, atmospheric transport, and relative humidity are investigated based on measurements at Basic Environmental Observatory (BEO) station, peak Musala (2,925 masl) for the period January 2009–January 2010. Data are chosen at 0:00 and 12:00 GMT every day. Main methods employed in this research are statistical—nonparametric tests of Mann–Whitney and Spearman. The main conclusion is that greater aerosol load at peak Musala is connected with transport of air masses from north to east horizon quarters. Bigger particles with longer lifetimes come from there. Air coming from the south horizon quarter is aerosol clearer. Relative humidity shows opposite distribution—higher values for transport from south horizon quarter. Correlation between this parameter and aerosols is negative with significant but small value. Distribution of blue, green, and red scattering and backscattering coefficients is similar to distribution of total aerosol concentration. Correlations between scattering and backscattering coefficients and total aerosol concentration are significant and positive. Courses of total aerosol concentration; diameter of particles with maximum concentration; and blue, green, and red scattering and backscattering coefficients have summer maximum and winter minimum. Diurnal course of total aerosol concentration in the two main seasons, winter (January) and summer (July), has day maximum and night minimum. Aerosols at peak Musala are predominantly of transparent or translucent type. The calculation of Ångström exponent α is more precise by using scattering coefficients. The nephelometers data could successfully characterize the haziness of the atmosphere above peak Musala.

DETECTION OF CORONAL MASS EJECTIONS (CMEs) IN THE PERIOD OF MARCH-MAY 2012 AT MOUSSALA PEAK

A large number of geoeffective solar events were registered during the period of March–May 2012. The events were detected as Forbush effects due to Coronal Mass Ejections (CME) occurring in March–April 2012 and a rare Ground Level Enhancement (GLE) in May, produced by region NOAA 1476 moderately strong (GOES class M5.1) flare at 01:25 UT on 17 May 2012 [1]. The data from permanently operational Cherenkov-water telescope of Basic Environmental Observatory at Moussala are used for observation of those activities. The magnetic IMF disturbances and resulting Forbush decreases were registered with high level of confidence. However, the GLE event detection was not confirmed statistically. The inter-comparison between detector responses of those events is used for preliminary study of the future space weather investigations in the Basic Environmental Observatory at Moussala.