About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno
A stragne and wonderful day
Many strange1 and wonderful sights were seen yesterday; I could feel the excitement out there as one cloud microstructural mystery after another regaled our Catalina skies.
How cold are these clouds? Lets look at the TUS sounding, launched at about 3:30 AM yesterday morning.
That bank of Altocumulus was racing at more than 50 mph toward Catalina, and so it got here in a hurry. And, as it got closer, it was also getting more into some airways at that height, possibly descents into PHX since the height of those clouds was below normal jet cruising levels at 23,000 feet Above Sea Level.
Now for the aircraft effects. Hardly a few minutes go by before aircraft began marking up this cold Altocumulus layer. Notice that it doesn’t seem to be producing much or any ice on its own, making aircraft inadvertent seeding lines and holes where tremendous numbers of ice crystals are generated immediately present. Here’s the first of many:
Heading for Catalina, this:
Here’s the south end of that ice canal:
Looking straight up at the icy heart of a hole punch region caused by an aircraft. I am sure you have never done this before! This is gonna be a great blog with all these new things for you!
As the south end of the original ice canal began to enter the refraction zone for simple ice crystals around the sun, usually at the 22° degree halo position, things began to light up with a particularly bright circumzenithal arc (more often observed on a halo) or colorful (in this case) partial “reverse halo”. The colors (iridescence) due to the refracting of light within very small ice crystals. Normally iridescence is seen near the sun in Cirrocumulus clouds or the then edges of other droplet clouds. Very exciting.
Then this strange sight:
The day closed out with a lower layer of Altocumulus moving in, this layer, according to the TUS sounding, at “only’ -17° C, and little ice detected. Below, at 2:09 PM:
U of AZ mod thinks so light rain will develop around here in the mid-later afternoon.
The End
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1“stragne” above, originally an inadvertent typo, but left in place as another cheap trick to get draw the curiosity of readers who might wonder what stragne is.
By Art Rangno
Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.
Is there any place on earth that can produce so many different kinds of clouds in one day?
Hi, Jim,
Well, as far a cloud visibility goes, how many we can see over such a large expanse of sky, it would be hard to beat. Maybe in the Plains States, but then you wouldn’t have the orographic clouds produced by our mountains.
And in humid, cloudy climates overall, the gorgeous scenes we are privy to are often obscured by low clouds. And, we don’t have too many contrails as a rule, nor smokey skies like they do around big cities.
So, we have lots to be thankful for right here in little ole Catalina!
a
Thanks, Art, for validating my suspicions. Yes, we have a lot to be thankful for, and the sky puts on a show almost every day.
Jim
Is there any place on earth that can produce so many different kinds of clouds in one day?
Hi, Jim,
Well, as far a cloud visibility goes, how many we can see over such a large expanse of sky, it would be hard to beat. Maybe in the Plains States, but then you wouldn’t have the orographic clouds produced by our mountains.
And in humid, cloudy climates overall, the gorgeous scenes we are privy to are often obscured by low clouds. And, we don’t have too many contrails as a rule, nor smokey skies like they do around big cities.
So, we have lots to be thankful for right here in little ole Catalina!
a
Thanks, Art, for validating my suspicions. Yes, we have a lot to be thankful for, and the sky puts on a show almost every day.
Jim