Geometric albedo node of their orbit, and hence lie on the ecliptic. In practice, measurements at small nonzero phase angles are used to derive the parameters which characterize the directional reflectance properties for the body (Hapke parameters). The reflectance function described by these can then be extrapolated to zero phase angle to obtain an estimate of the geometric albedo. For very bright, solid, airless objects such as Saturn's moons Enceladus and Tethys, whose total reflectance (Bond albedo) is close to one, a strong opposition effect combines with the high Bond albedo to give them a geometric albedo above unity (1.4 in the
Surface Heat Budget of the Arctic Ocean that solar radiation is the dominant heat source to the surface. It accounted for the change in open ocean from a 5% maximum in June and the changes in albedo. Approximately 8% of incoming solar radiation was absorbed into the ocean through the ice. The scientists were able to define parameters for near-surface turbulence that characterize the degree to which air movement can cool or warm the surface of the ice, seasonally. In summer, the surface becomes rougher and slows down air flow. The lidar cloud measurements and balloonsonde temperature and turbulence data allowed scientific characterization of the role of