QUANTITATIVE-ANALYSIS OF SEA-ICE DRAFT .2. APPLICATION OF STOCHASTIC MODELING TO INTERSECTING TOPOGRAPHIC PROFILES

A recent upward looking sonar profile survey of a similar to 10-km by 10-km area beneath the Arctic ice serves as a basis for an exploratory analysis of the quantitative characteristics of sea ice draft. In a c ompanion paper (Goff, this issue) a method was developed for estimatin g profile statistical parameters and their uncertainties. These includ e mean draft, rms variation, characteristic length, fractal dimension, and normalized skewness. Here this methodology is applied to the inte rsecting profile data set, yielding 160 separate estimates for each pa rameter. Although not completely two-dimensional, the data nevertheles s allow an opportunity to investigate some aspects of topographic anis otropy. Our most significant observations are (1) a strong positive co rrelation exists between fractal dimension and characteristic length, while normalized skewness is weakly negatively correlated with both pa rameters; (2) high and low rms/mean ice are morphologically distinct i n the rms versus characteristic length and fractal dimension versus ch aracteristic length parameter spaces; (3) the overall correlation betw een rms and characteristic length can be explained entirely by the dif ference between high and low rms/mean type morphology; and (4) anisotr opy appears to exist on a local scale but is highly variable over the entire survey. These observations could be explained by a systematic v ariation in morphology with age, perhaps including a progressive super position of deformation events, and/or by regionally variable anisotro py.