To generate these curves, and were first estimated over a 10 day window using linear regression of the versus incidence angle. The window was moved one day and the process repeated to estimate time-averaged coefficients. To illustrate changes in the measurements as a function of time, the estimated value in the upper panel was used to estimate an value for each measurement. A 10-day moving average of these values is included as a solid line in the lower panel. The scatter in as well as the occurrence of significant, rapid variations are evident.
Gaps are due to missing data.
Significant changes occur in as a function of time, with a moderation in these changes with ice sheet altitude. The scatter in Fig. We note increased values and reduced scatter in the measurements as fall surface cooling progresses. Subsequently, signatures stabilize. It appears that the further upslope one gets, the less the impact of summer temperatures upon the physical properties and resulting microwave signatures.