Annual net balance of North Cascade glaciers, 1984-94

Annual net balance on eight North Cascade glaciers during the 1984-94 period has been determined by measurement of total mass loss from firn and ice melt and, of residual snow depth at the end of the summer season. Overall spatial density of measurement points is 200 points km(-2). Mean annual balance of North Cascade glaciers from 1984 to 1994 has been -0.38 m a(-1). The resulting 4.2 m loss in water-equivalent thickness is significant, since North Cascade glaciers have an average thickness of 30-50 m. Cross-correlation of annual net balance for eight glaciers ranges from 0.83 to 0.97. This indicates the mass balances of the eight glaciers have been responding similarly to climate conditions despite their range of topographic and geographic characteristics. Annual net balance of individual glaciers was correlated with climate records. The highest ablation-season correlation coefficient is mean May-August temperature, ranging from 0.63 to 0.84. The highest accumulation-season correlation coefficient is total accumulation-season precipitation, ranging from 0.35 to 0.59.