Growth from of ice crystals grown in air at low supersaturation and their growth mechanism

The morphological instability and the growth mechanism of ice crystals grown in air at -30℃ and at supersaturation below 4% have been experimentally studied. Whether ice crystals grown under this condition would develop into long prismatic columns or into thin plates is dependent on the emergence of active screw dislocations on the {0001} or {1010} faces of the crystals. The morphological instability of ice crystals grown in air at low supersaturation is related to the emergence of active screw dislocations near the corners of the {0001} or {1010} faces. From the experimental results, the growth form and the growth mechanism of snow crystals at low supersaturation observed at Mizuho Station, Antarctica are discussed