FW: Indian Summer, The Smoky Mountains, and pollution

[James A. Landau]

In a message dated 3/23/2003 7:03:18 PM Eastern Standard Time,
sclements at NEO.RR.COM writes:

> From my reading of your post, particularly the part that I have copied here,
> today you saw a blue effect, even though there could be no terpenes, etc,
> coming from the trees yet? And no haze, etc, which might be more common in
> Summer or Fall.

I merely observed that groups of bare deciduous trees several miles down the
road showed up as a bluish-gray, whereas nearer trees were brown.  For all I
know it may have been a high-pollution or high-haze day.

It may be that bare trees on the skyline in the distance generally show up as
blue-gray.  The branches are usually a dark brown and there is blue sky
showing through the gaps in the branches.  But the trees are so far away that
the dark-brown-to-almost-black of the branches blends with the much lighter
blue of the sky to give the blue-gray appearance.

The mountain does not have to appear blue in all seasons to acquire the name
"Blue".  If it were frequently bluish for a couple of months per year, that
would be characteristic enough to give it that name.  Perhaps the blue is
most prominent in the winter and the "characteristic" haze is actually a
myth, caused by frequent sightings in which the mountain appears to be hidden
by a blue haze.

Note that the Blue Ridge, Blue Mountain in Pennsylvania, and the Great
Smokies are all visible from a distance, whereas most of the rest of the
Appalachian chain is not. Hence if there is a blue effect for mountains
covered with deciduous trees, it would be most noticeable in the hills on the
above list and not very noticeable elsewhere.

In the western US there are many mountains and ridges visible from great
distances---the Front Range of the Rockies, for example.  However, the
Rockies get their name because much of them is above the tree line and
therefore bare rock, and you don't get the effect of blue sky showing through
dark branches (if that is indeed the cause of "blue").

One final note:  "Vermont" is French, "Vert Mont" or "Green Mountain", and
there is a range called the "Green Mountains" in it.  Are the Green Mountains
mostly covered with evergreens, in which case you won't see bare branches in
winter?

        - Jim Landau