01.02.2012
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Thermal Wave Glory
charles baughman <<big-bird>>
writes:
The view was breathtaking. I was high, way above the clouds in
very smooth, serene air and all alone. I was really glad I had a camera and
hoped the shots were good. I saw Patrick climbing up to 8700' and I radioed to
him, "Get your butt up here, this is incredible air." He responded, "I'm trying,
I'm trying! During the flight I had radioed to my flying friends several times
how wonderful the conditions were and apparently sounded like an exuberant
little kid at Christmas. The return reply could have easily been, Shut up, I am
busy.
The forecast on Saturday, Oct 22, for Pine Mt. Oregon was for lift to 8000' and
a 10 to 15 mph west wind which is straight in at launch. Pine Mt. is over forty
miles east of the Cascade Range and the westerly winds put it in a lee side
condition, which is very dry with very few trees. This is Central Oregon,
categorized as a high desert area. These conditions make for good flying and
cross country potential. There are many days of thermal flying in the summer
with cloud base ranging from 10000 to 14000 and occasionally higher. Landing
areas are plentiful at about 4300 where the terrain is mostly flat and treeless
but usually has sagebrush ranging from two to five feet tall. Pine Mt. is a big
rocky volcanic mountain with several long ridges. There are four main upper
launches of which the west launch, at 6100, is the favorite launch for hang
gliding. The paragliders use the four upper launches and very often use the
convenient lower launches on the northwest facing ridge which are very close to
a parking area.
I launched at 2:00 PM and found conditions to be good, especially for this late
in the year. Five hang gliders and seven paragliders launched that day.
Paragliders Steve Roti and Scott Maclowry said they got up to 7700, where they
found the wind to be at their maximum, so they flew out and down. I got high in
good lift with light turbulence. The cumulus were dry and wispy at 10000'. I
worked the lift back to the Antelope Launch area. I would have continued east
but I saw no appetizing cumulus and decided to head back upwind to the ridge. I
was able to make it back to the top of the ridge because of the superior
performance of the Atos type glider.
My glider is an Atos VR11. It is classified as a rigid wing hang glider and has
a very wide span, flaps, spoilerons, winglets, and a horizontal stabilizer. The
flaps and stabilizer are coupled together and the setting can be changed in the
air with a pull cord. Pitch and roll are controlled by weight shift movement. It
has an excellent glide ratio, and that allows me to--- go places.
After I flew back to the launch area, I scratched for lift with Scott Michalek
and Tim Reynolds and later circled up to Patrick Kruse. After some searching, I
entered a strong smooth thermal with my climb averaging 700 fpm. I love fast
climbs, especially when they are smooth. As I climbed higher and higher, I
looked up for a cloud, which I could not find, and I topped out at 12100' and
2000' above the clouds. The entire climb was cloudless. As I was cruising around
in the smooth upper layer, I noticed a glory on a cloud. The glory is an optical
phenomena that falls into the "Water Droplet Arc" category similar to rainstorm
rainbows. The physics of the glory are not fully understood but a basic
explanation is that glories are rainbow-colored rings produced by
backscattering, surface wave effects, and diffraction from small, uniformly
sized water droplets such as those in clouds and fog. The colored rings are seen
around the anti solar point, directly opposite the sun along a line running
through the observers location. Droplet characteristics are important in the
type of glory formation. Smaller droplets produce larger glories. Uniform
droplets have more rings, and they are more distinct as well. The glorys
angular size depends only on the diameters of the cloud droplets. The distance
from the cloud has no effect on how large it looks. All of the glories in my
pictures look to be the same angular size even though I was at different
distances from the clouds. The shadow itself can change size depending on the
distance from the cloud. The glider shadow in my pictures is small and off
center in the glory. The camera is not centered on the glider. it is on the left
wingtip aimed to the right and forward and it sees its part of the shadow in
the center of the glory.
The glory sighting was mesmerizing. I had seen these before, but this time I was
able to stay up at cloud height for an extended period of time while taking
pictures. Most of the clouds I used to make the glory shots were elongated and
wedge shaped from west to east and the cloud top billows appeared to be rising
and showing a wind increase. I flew along the sunny south side of the cloud to
get multiple shots. There was continuous 300 to 500 fpm lift near the cloud in
clear air. I had to dive to stay low enough to get the glory shots. It was as if
I was making speedy ridge runs, except I was flying upwind taking shots, and
downwind to line up for another shooting run. After I made multiple cloud
passes, the conditions started to deteriorate as the clouds were dissipating.
The magical air had lasted about 45 minutes. I flew back to the ridge and as I
watched my altimeter unwind my thoughts turned to the camera. I really wanted
the shots to be there when I uploaded, because no one would believe or could
imagine and enjoy this story without pictures.
I have had discussions about this soaring condition with Gary Osoba, a hang
glider designer back in the 70s when new designs were coming out monthly. Gary
also had some very innovative designs and currently holds many sailplane records
and makes attempts to break soaring records every year. Gary had an explanation
for my soaring condition: The condition that allowed you to climb to altitudes
above the clouds and then fly along in front of them, as you might do in ridge
lift, are rather uncommon. First, there appeared to be a convergence of two air
masses with markedly differing moisture levels. Secondly, the winds aloft were
such that once you climbed to a position in front of existing clouds, you could
surf them in a thermal induced wave. As such, the clouds line up in a manner
that results in the upper winds to flow over them, creating mild wave lift and
sink in a pattern. I would like to add to this that the elongated wedge shape
of the clouds was very interesting, possibly indicating that a drier, colder,
faster moving air mass was converging, and riding up the cloud top, which
increased the instability and helped to form and pull the cloud into a wedge
shape.
After many years of flying, this flight is a strong reminder that the potential
for new experience and discovery is always there, just waiting to be realized.
In my early days of flying I discovered, for myself, that even a primitive
standard hang glider could go up in a thermal using the circling method. We have
come a long way since then. Through the years advancements in equipment,
improvements in technique, and overall knowledge have enhanced our enjoyment in
all aspects of flying. This flight had some phenomenal firsts for me: I have
never gained anywhere near 2000' above the lower thermal formed clouds. I have
never flown next to a small cloud in clear air and consistently gained 500 fpm.
I have never had such a euphoric glory experience. The pleasure of this
adventure was magnified by the unbelievable smoothness and buoyancy of the upper
layer.
Later that night, I expressed to my flying buddies, I feel like a 1000 watts.
You could plug a toaster into me.
http://OzReport.com/1328125674
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