A comparison of glacier melt on debris-covered glaciers in the northern and southern Caucasus

The glacier coverage in the Caucasus Mountains underwent considerable changes during the last decades. In some regions, the observed reduction in glacier area is comparable to those in the European Alps and the extent of supra-glacial debris increased on many glaciers. Only a few glaciers in the Caucasus are monitored on a regular basis, while for most areas no continuous field measurements are available. In this study, regional differences of the conditions for glacier melt with a special focus on debris covered glacier tongues in the well-studied Adyl-su basin on the northern slope of the Caucasus Mountains (Russia) is compared with the Zopkhito basin which has similar characteristics but is located on the southern slope in Georgia. The paper focuses on the effect of supra-glacial debris cover on glacier summer melt. There are systematic differences in the distribution and increase of the debris cover on the glaciers of the two basins. In the Adyl-su basin an extensive debris cover on the glacier tongues is common, however, only those glacier tongues that are positioned at the lowest elevations in the Zopkhito basin show a considerable extent of supra-glacial debris. The observed increase in debris cover is considerably stronger in the north. Field experiments show that thermal resistance of the debris cover in both basins is somewhat higher than in other glaciated regions of the world, but there is also a significant difference between the two regions. A simple ablation model accounting for the effect of debris cover on ice melt shows that melt rates are considerably higher in the northern basin despite a wider debris distribution. This difference between the two regions can be attributed to different meteorological conditions which are characterised by more frequent cloud cover and precipitation in the south. Furthermore ablation is strongly influenced by the occurrence of supra-glacial debris cover in both basins, reducing the total amount of melt on the studied glaciers by about 25 %. This effect mitigates glacier retreat in the lower sectors of the ablation zones considerably. The sensitivity to moderate changes in the debris cover, however, is rather small which implies only gradual changes of the melt regime due to debris cover dynamics during the near future

On the Representativeness of Data from Meteorological Stations in Georgia for Annual and Semi-Annual Sum of Atmospheric Precipitation Around of These Stations

Results of study of the representativeness of data from 39 meteorological stations in Georgia for annual and semi-annual sum of atmospheric precipitation around of these stations are presented. Period of observation – from 1936 to 2015. In particular, it was found that in general for the year data of meteorological stations on precipitations are representative around these stations on distance from 19 km (Mta-Sabueti, Kobuleti) to 46 km (Gori); in cold period of year - from 13 km (Mta-Sabueti) to 49 km (Zugdidi); in warm period of year - from 20 km (Chokhatauri) to 43 km (Pasanauri)

Comparison of data from ground-based and satellite measurements of the monthly sum of atmospheric precipitation on the example of Tbilisi city in 2001-2020

The data of ground-based (Prec_MS) and satellite (Prec_Sat) measurements of the monthly sum of atmospheric precipitation are compared using the example of Tbilisi in 2001-2020. In particular, the following results are obtained. In general, for all observational data (240 months), Prec_MS values vary from 0 to 267.3 mm, and Prec_Sat - from 3.0 to 184.0 mm. Their average values are 43.6 and 64.8 mm, respectively. Monthly mean values of Prec_MS vary from 16.7 mm (January) to 93.2 mm (May) and Prec_Sat values – from 32.5 mm (December) to 114.4 mm (May). Ground-based measurements are lower than satellite data for all months of the year. The difference between the average values of Prec_MS and Prec_Sat over 20 years varies from -8.8 mm (November) to -33.4 mm (March). Ratio between the average values of Prec_MS and Prec_Sat varies from 40.6 % (January) to 81.5 % (May). There is a direct linear correlation between the studied parameters. For all observational data (240 months) coefficient of correlation is 0.86 (high correlation), for separate month changes from 0.65 (July, moderate correlation) to 0.94 (April, very high correlation). Coefficient of correlation between average values of the studied parameters is 0.97 (very high correlation)

Preliminary Results of a Study of the Relationship Between the Variability of the Mean Annual Sum of Atmospheric Precipitation and Landslide Processes in Georgia

Preliminary results of the study of the relationship between the variability of the mean annual sum of atmospheric precipitation and landslide processes in Georgia for 32 years are presented. In particular, it was found that with an increase in the annual sum of atmospheric precipitation, the tendency of increase in the number of landslides is observed in accordance with a second power of polynomia

PREVENTION OF ANTRACYCLIN ANTIBIOTIC DOXORUBICIN СARDIOTOXICITY: A ROLE OF ACE-INHIBITOR PERINDOPRIL

<p><strong>Aim</strong> – to study how anthracyclines influence on cardiovascular system in patients with lymphomas and whether angiotensin-converting enzyme inhibitor Perindopril is cardioprotective in these patients.</p><p><br /><strong>Subjects and methods</strong>. 26 patients with Hodgkin’s disease and non-Hodgkin’s lymphomas were followed before and after treatment with<br />doxorubicin. 12 of these patients with arterial hypertension received angiotensin-converting enzyme inhibitor Рerindopril, 10 mg/d, during<br />treatment with doxorubicin. Cardiological evaluation was performed before and the next day after chemotherapy. Average dose of Doxorubicin was 34,99 ± 13,23 mg/m2.</p><p><br /><strong>Results.</strong> In patients receiving anthracyclines deceleration time DT increased significantly, a significant reduction in heart rate (HR), cardiac<br />output (CO) and cardiac index (CI) were observed also (рDT = 0,037, pHR = 0,048, рСО = 0,007, рCI = 0,007). In patients simultaneously<br />treated with Perindopril these parameters were not statistically different (рDT = 0,92, pHR = 0,22, рCO = 0,35, рCI = 0,39).</p><p><br /><strong>Conclusion.</strong> Administration of anthracyclines (average dose of Doxorubicin 34,99 ± 13,23 mg/m2) leads to DT of the left ventricle and<br />reduction in HR, CJ and CI. Simultaneous treatment with Perindopril in patients receiving anthracyclines preserves DF and prevents heart hemodynamics abnormalities.</p