| T B McKee Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 303-491-8545 |
S K Krueger Department of Meteorology University of Utah Salt Lake City, UT 84112 801-581-6136 |
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| Sponsor: S K Cox, AGU Member #013431674 | |||||
Boundary layer structure beneath the primary inversion has been observed with rawinsondes launched eight times per day during most of June 1992 at Porto Santo. The usual structure is to have two layers with a sub-cloud layer and a cloud layer above capped by the primary inversion. Clouds were present in 61% of the sounding taken in June 1992. Early results indicate that almost 50% of the clouds were 300 m or less in thickness and clouds thicker than 1000 m occurred less than 15% of the time clouds were present.
The two layer structure of the boundary layer is apparent with and without
clouds. Four types of vertical structure are common in the cloud layer. They
include a cloud layer vertically filled with cloud, a cloud layer with cloud
near the top and bottom, one with a cloud near the top only, and one with a
cloud near the bottom only. Similar vertical structures of moisture are
observed when no cloud is present. Mean soundings will be shown for each of
these types with frequency of occurrence of each. Time series of the evolution
(or advection) of the types will be discussed along with an analysis of cloud
thickness. Time varying depth of the sub-cloud and cloud layers will be
presented with the cloud types.