. >> well, when these people come out of the icefield and expeence thelacial vironmt, by king measurements, they can see how that ecosystem is changing this year and in years before. >> to be on the juno icefield is a fantastic experience for me, and part of a major program that monitors mass balance of an important glacier, and in addition, it gives me the opportunity to try and contribute to the scientific development of young scientists. >> mass balance indicates the health of a glacier. a positive mass balance means that the glacier is growing. a negative mass balance means that it is shrinking. the older a mass balance record is the more valuable it becomes. long-running studies provide a historical average against which this year's data can be compared, showing how the climate has changed and what may happen in thefuture. >> the mass balance data that's been collected by the jirp program is an extremely important record because it goes back as far as 1946, and there are probably only about 30 glaciers in the world that have been monored forass balance for 10 or more years. >> a glaci