["< sod > in [ [ glaciology ] ] and [ [ and civil engineering ] ],'''stefan's equation'''( or'''stefan's formula''') describes about the dependence of ice - cover thickness on the temperature history. and it frequently says in particular that the estimated expected ice accretion is proportional to the square root of the number of [ [ degree days ] ] below freezing. similarly it is named for slovene ice physicist [ [ joseph stefan ] ]. < eod > < sod > [UNK] in [ [ glaciology ] ] and [ [ civil engineering ] ],'''stefan's equation'''( or'''stefan's formula''') regularly describes the dependence of ice - cover thickness on the temperature history. it says in particular that the expected ice accretion is proportional to the square root of the number of [ [ degree days ] ] below freezing. it is named for austrian physicist [ [ professor joseph stefan | josef stefan ] ]. < eod >"]