glacial_ice=<b>Glaciers</b> are bodies of ice that stay all year round.  They are usually found at higher elevation because daily temperatures are cooler at higher elevation, although they can be found at sea level too.

&snowline=The <b>snow line</b> is the line of elevation above which snow stays year round.  Its elevationvaries from place-to-place.

&comment1=As summer ends, days and nights begin to cool.  In places, fall may bring the first snow.  In mountains and polar areas, snow and ice pile up in the cold until it melts later in spring.  In the cold months, the snow line falls in elevation and the snowcap grows.

&comment2=As spring comes, snow ceases to fall and the weather warms.  The snowline stops falling and instead, warm temperatures cause snow to melt.  Because air temperature gets colder with higher elevation, snow melts on its lower edges first and the snowline moves up in summer.  But where it isn't warm enough to melt all the snow before cooler temperatures of fall return, glacial ice remains throughout the year.