The world’s glaciers and ice sheets are changing. Observations of glacier velocity (speed of ice flow), thickness, length and area alongside measurements of climate help us to understand this change. We can monitor these changes via remote sensing (using data from sensors mounted remotely, on things like UAVs and satellites), as well as from in situ measurements on the ice surface taken during fieldwork.
Remote sensing allows us to measure and monitor large areas all at once. It also allows us to undertake repeat measurements at different time scales. Alternatively, in situ measurements of glacier mass balance allow detailed observations and some have been repeated for decades. These long datasets provide rare glimpses into the long term behaviour of glaciers under a changing climate.
Is there any studies done for Indian Himalayas by any Scientists/group of scientists? If so refrences thereof.
I have not time to give you chapter and verse, but you can look at the webpages for Journal of Glaciology, Annals of Glaciology and the Cryosphere and check lists of authors. You will find a great increase in Indian papers (Chinese and Pakistani as well) over the last 20 years. In the Alps and Scandinavia we have a longer period of active work but Indian scientists are very diligent in supplementing their short field records with data from space satellites and modelling.