144
by both western disturbances in the winter and monsoon circulation in the summer.
Some recent studies suggested that glaciers in this basin predominantly receive
accumulation in the form of snow, receiving ∼80% of its annual precipitation from
mid latitude westerlies during winter (October–April) and ∼20% from ISM during
summer (Azam et al. 2014, 2016; Tawde et al. 2017).
3 Mass Budget Investigations in Svalbard and Himalaya
3.1 Svalbard
In 1950, the Norwegian Polar Institute started the first systematic mass balance
studies on Finsterwalder Breen glacier on the southern side of Van Keulen Fjorden.
These expeditions took place every other year from 1950 to 1966. In 1966, investigations were extended to Austre Broggerbreen (6.1 km
2
) glacier and, a year later, to
Lovenbreen glacier (5.5 km
2
) in the Kongsfjord area. Both glaciers are located close
to Ny-Alesund (79°N; 12°E), on the northwest coast of Spitsbergen. The measurements have been carried out yearly since 1966. Observations for both accumulation
and ablation have been taken by the direct glaciological methods. Russian glaciologists started systematic annual mass balance measurements in 1966 on Voringbreen
glacier in Gronfjorden. During 1973–1976, they extended the studies to three other
glaciers, two in west-central Spitsbergen and one on the east coast. Polish researchers have studied the mass balance on Hansbreen glacier (57 km
2
) in Hornsund, on
the southern Spitsbergen, since 1989 and its frontal position has been mapped for
30 years (Jania and Hagen 1996; Finger et al. 2013). French scientists, in cooperation with Norwegians, have also carried out indirect measurements of mass
balance through shallow core drilling and detection of radioactive reference layers.
These investigations indicate the mean annual accumulation at the drill sites since
the layers were deposited. Several cores at different altitudes in the accumulation
area will permit the calculation of the accumulation area ratio and thus indicate the
net mass balance for the whole glacier (Lefauconnier et al. 1994). Both the
Norwegian and the Russian mass balance measurements have been carried out on
relatively small (2–6 km
2
) isolated cirque- or valley-glaciers close to the coast which
lie at altitudes below 500 m (a.s.l.) (Dowdeswell et al. 1997). Only sporadic measurements have been made on the larger glaciers and ice caps. Therefore, in 2011,
mass balance investigations were started on Kongsvegen (105 km
2
) by NCPOR.
Data revealed that there was no striking changes in net annual mass balance
except normal inter variability during last three decades of twentieth century. The
mean annual specific net balance of studied glaciers by different institutes/universities has been given in the Table 1. There was no significant trend observed in the
summer melting and winter accumulation. Most of the summer ablation was greater
than the winter accumulation except for few observations (Hagen et al. 1993, 2003).
There was a steady decrease in the volume of ice masses of these glaciers, however
there was no evidence for significant increase in melting (Jania and Hagen 1996).
P. Sharma et al.
by both western disturbances in the winter and monsoon circulation in the summer.
Some recent studies suggested that glaciers in this basin predominantly receive
accumulation in the form of snow, receiving ∼80% of its annual precipitation from
mid latitude westerlies during winter (October–April) and ∼20% from ISM during
summer (Azam et al. 2014, 2016; Tawde et al. 2017).
3 Mass Budget Investigations in Svalbard and Himalaya
3.1 Svalbard
In 1950, the Norwegian Polar Institute started the first systematic mass balance
studies on Finsterwalder Breen glacier on the southern side of Van Keulen Fjorden.
These expeditions took place every other year from 1950 to 1966. In 1966, investigations were extended to Austre Broggerbreen (6.1 km
2
) glacier and, a year later, to
Lovenbreen glacier (5.5 km
2
) in the Kongsfjord area. Both glaciers are located close
to Ny-Alesund (79°N; 12°E), on the northwest coast of Spitsbergen. The measurements have been carried out yearly since 1966. Observations for both accumulation
and ablation have been taken by the direct glaciological methods. Russian glaciologists started systematic annual mass balance measurements in 1966 on Voringbreen
glacier in Gronfjorden. During 1973–1976, they extended the studies to three other
glaciers, two in west-central Spitsbergen and one on the east coast. Polish researchers have studied the mass balance on Hansbreen glacier (57 km
2
) in Hornsund, on
the southern Spitsbergen, since 1989 and its frontal position has been mapped for
30 years (Jania and Hagen 1996; Finger et al. 2013). French scientists, in cooperation with Norwegians, have also carried out indirect measurements of mass
balance through shallow core drilling and detection of radioactive reference layers.
These investigations indicate the mean annual accumulation at the drill sites since
the layers were deposited. Several cores at different altitudes in the accumulation
area will permit the calculation of the accumulation area ratio and thus indicate the
net mass balance for the whole glacier (Lefauconnier et al. 1994). Both the
Norwegian and the Russian mass balance measurements have been carried out on
relatively small (2–6 km
2
) isolated cirque- or valley-glaciers close to the coast which
lie at altitudes below 500 m (a.s.l.) (Dowdeswell et al. 1997). Only sporadic measurements have been made on the larger glaciers and ice caps. Therefore, in 2011,
mass balance investigations were started on Kongsvegen (105 km
2
) by NCPOR.
Data revealed that there was no striking changes in net annual mass balance
except normal inter variability during last three decades of twentieth century. The
mean annual specific net balance of studied glaciers by different institutes/universities has been given in the Table 1. There was no significant trend observed in the
summer melting and winter accumulation. Most of the summer ablation was greater
than the winter accumulation except for few observations (Hagen et al. 1993, 2003).
There was a steady decrease in the volume of ice masses of these glaciers, however
there was no evidence for significant increase in melting (Jania and Hagen 1996).
P. Sharma et al.