**7. Conclusions**

Why is then no trend in the development of Snezhnika glacieret, if the temperature rise is a fact? The answer is sought in the influence of precipitation, but data about this climatic element are almost missing in Pirin. However, analysis of precipitation data from Musala (with lots of uncertainties) shows that the stagnation of Snezhnika can be due to the higher sums of

As the annual precipitation in the high parts of Pirin is suggested to be around 1000–1100 mm/ year, 650–700 mm of which during the accumulation season [26, 42], Snezhnika is fed to a greatest extent by avalanche and windblown snow. Thus, it receives snow amounts much larger than the actual sum of atmospheric precipitation. On the contrary, Banski suhodol has much smaller avalanche catchment [8]. It relies most of all on shading, and its variations through years are smaller than those of Snezhnika [3]. Sadly, precipitation data from the devices installed in Pirin

No climatic data are available from the high mountain areas of Prokletije and Durmitor, the closest mountain station being on Bjelašnica peak in Bosnia and Herzegovina (2067 m a. s. l.). Extrapolations of temperature for the last decade however suggest that around 2150 m a. s. l., annual temperatures are around +2°C and more, and even near the highest glaciers, they are positive [12, 14, 18]. These are however temperatures for open slopes. In negative forms, values are by no doubt lower but still high to sustain glaciers. In the Western Balkans, the existence of perennial ice is favoured by the much greater precipitation: annual amounts for the highest areas of Durmitor are about 2600 mm [18, 33], and for the central and western parts of Prokletije 2500–3300 mm, 2/3 of this amount falling in the cold half of the year [12, 43, 48]. This enables formation of glaciers even at altitudes around 2000 m in strongly shaded sites. The plateau surfaces in the south of Debeli namet and Kolata glaciers serve as great sources of snow, so the actual amount of snow can be more than twice the winter precipitation sum. Glaciers around Mt. Jezerce rely most of all on high altitude (comparable to that of Snezhnika in Pirin) and precipitation around 2500 mm/year and those in Karanfili range mainly on strong shading. Glaciers in Hekurave area, especially Mertur glacier, have always been in good condition in the last years (even in 2012 and 2016). This is due to their high altitude, and, possibly due to much higher precipitation (probably around 3000 mm/year), a result of their southern position and

The different trends in small glaciers in the Western and the Eastern Balkans, which were observed in the last two balance years (2014/2015 and 2015/2016) can be explained with some synoptic events of accidental character that affected unevenly the territory of the Peninsula. After a relatively snowless winter, in the beginning of March 2015, a cyclone coming from Greece reached Southern Bulgaria and deposited abundant snow in high mountains, triggered avalanches and piled more than 10 m of snow over Snezhnika and smaller but still amount over Banski suhodol (as it is less prone to avalanche). At the same time, mountains in the western part of the Peninsula did not face that cyclone and remained with little snow. After the summer, melt resulted in a positive balance for Snezhnika, a slightly negative for Banski suhodol and a strongly negative for all glaciers in the Western Balkans. Similar situa-

winter precipitation, which have been registered in most of the years after 2004.

are not reliable [45, 47].

98 Glacier Evolution in a Changing World

greater proximity to the Adriatic.

tion occurred also after the next winter.

At least 16 small glaciers still exist in the mountains of the Balkan Peninsula. Prokletije mountain range provides the best conditions for glacier preservation in the region. Favouring factors for glaciers in the Western Balkans are the high precipitation and the greatest dissection of relief that provides optimal shading conditions. Here, the lowermost small glaciers and snow patches on the Balkans are found. Favouring factors for glacier formation in Pirin are the higher altitude and avalanche occurrence. Small glaciers on the Balkans, which are among the southernmost in Europe, still manage to survive in conditions of climate warming, proved by data from high mountain stations. Further, in a longer term (the last 20 years), they have shown no trend towards shrinkage. Although their area at the end of the balance year shows some correlation with summer temperatures, the neutral balance is reached due to the increased winter precipitation, especially in the last 12–13 years. These facts support the suggestion that small glaciers in such marginal environmental conditions may last much longer than expected.
