|
meteoptic-l [ät] ursa.fi
message archive
This is meteoptic-l [ät] ursa.fi message archive.
Note, your can reply the messages on this page only if your
are already subscribed the list.
» To the end of the list/message
> 1) You state that the contrail was under the cirrus layer, and
> that this was somehow obvious from the "structure". Can you
> elaborate on this? From your description of the shadow it sure
> sounds like the contrail was above the cirrus. On the other hand,
> the explanation may be the same as for 2) below...
In my opinion, sometimes the altitude order of two layers,
in this case contrail and thin cirrostratus layer, could
be difficult to recognize.
Few days ago, right after Bill's message I check the sky.
In the Helsinki area there are lots of contrails. One of
these seems to be below cloud layer at the first look, but
more careful study it proved to be above the clouds. The
cloud layer was quite thin and transparent. I think one
reason could be that contrails and denser and they scatter
light more than thin cs clouds. So they are brighter than
clouds and seem to be closer.
Well this is only one speculation. Of course the geometry
between screening object (eg. contrail) and the screen
(clouds) should think carefully. It is very difficult to
observe correctly from far.
-Veikko-
|