Short term variability of atmospheric turbidity and optical turbulence in a desert environment

Variability of atmospheric turbidity calculated from direct beam solar radiation measurements and the transverse coherence length,r0, derived from differential image motion of stellar sources show pronounced fluctuations on the order of a few minutes under convectively unstable conditions in a desert environment. The quiescent periods, “neutral” events, when local near surface adiabatic conditions occur show substantial reductions in the fluctuations of the same quantities. Image motion results for nighttime (stable) conditions display slowing varying patterns with reduced short term (few minutes) variations.