Re: Mesozoic snow?

[Dora Smith <villandra@austin.rr.com>]

I have a question;  just how DO we know that the climate was cooler during
the Triassic?

If we know it was cooler, we should be able to know how cool it was, and
this would tell us if dinosaurs ever saw snow.

Well, that and the precipitation level.  We also somehow know that it was
dry.   Nevertheless, plants and certain large warm blooded and often
feathered reptiles managed to thrive.

Common sense does lead one to wonder how feathers were an advantage if the
temperatures continued to be tropical.

Some parts of the southwestern U.S. today, including central Texas, get cold
enough often enough in the winter for snow, but such a thing happens about
every five years and leaves sufficient snow for a three inch snowman.
Problem is that in the southwest cold and rain don't commonly happen at
once.    If the conditions are right for rain, which happens six times in a
typical winter, it isn't usually cold enough for snow.   If it is cold,
either high pressure with deep blue skies barreled in from the north, or a
major storm just went through and its northerly back end is cold and sunny.
If it rains more than six times, than it's an el nino winter and the
subtropical jet makes the weather.   Of course, that explains why most snow
falls in March, when tropical and northern air masses have big battles over
the south central United States.

Yours,
Dora Smith
Austin, Texas
villandra@austin.rr.com