Ground-based radar observations of snow stratigraphy and melt processes in the percolation facies of the Greenland ice sheet

Summ er melt is a prim a ry source of mass loss on the Greenl a nd ice shee t. An und erstanding of melt processes on the ice shee t, th eir connecti on with a tm osp heri c processes, a nd th e red istributi o n of meltwa ter is importa nt [o r ascerta ining the mass bala nce of th e ice shee t. High-reso lu tion radar measuremel1lS mad e in th e percola ti on zo ne of the Green la nd ice shee t revea l th e e\'oh'ing rad a r signa ture of summer surface melting a nd subsequ ent refreez ing of meltwa ter. A traverse ove r the snow surface has res ult ed in the first radar ma p of snow stratigraph y over a n ex tend ed di sta nce . The d omin a nt sources of bac k-sca tter in th e stud y area a re th e snow surface a nd effec ti vely continu ous annua l ice laye rs. \Ne sugges t app li ca ti ons of our results to help defin e th e ex lent of the percola ti on zone a nd to di scrimin a te betwee n regions where surface melt is los t to the sea a nd th ose where melt re freezes nea rl y in place .