THE EXTERNAL SEEING AND THE VERTICAL TEMPERATURE PROFILE IN THE SURFACE LAYER
J. Navarrete, ESO La Silla & Paranal Observatory
February 2006
Statistics of the last 4 years of operation in Paranal (2001-2004), over 778127, samples.
Figure 1: Histogram of the vertical temperature gradient between 30m and 2m above ground at Paranal (nighttime & clear sky only).
Figure 2: Histogram of the seeing measured at 6m above ground at Paranal for various levels of vertical temperature gradient between 30m and 2m above ground (nighttime & clear sky only).
Figure 3: Seeing records at 6m above ground at Paranal as a function of 30m wind direction (N=0, E=90) and of the vertical temperature gradient between 30m and 2m above ground (nighttime & clear sky only).
Figure 4: Vertical temperature gradient between 30m and 2m above ground (nighttime & clear sky only) as a function of wind direction (N=0, E=90) measured at 30m.
Figure 5: Wind rose measured at 30m for bad seeing conditions and strong vertical temperature gradient between 30m and 2m above ground (nighttime & clear sky only).
Figure 6: Wind rose measured at 30m for good to average seeing conditions and strong vertical temperature gradient between 30m and 2m above ground (nighttime & clear sky only).