Ice at the tops of clouds

[Simon Says]

Does anybody have an explanation why climbing through clouds we do not generally get any ice, but as soon as we hit the very tops of the clouds...."Bing"....."ICE" light. Usually just a trace of icing, but always coming through the tops.

I have always wondered why I usually pick up icing right at the very tops of the clouds.

 

[xkuzme1]

Because the clouds are filled with tiny ice crystals. Then near the tops of the clouds the warm sun just slightly melts the little crystals enough so that they will adhere to the ice detectors on the airplane. Sometimes when there is a higher saturation of tiny ice crystals in the clouds you will get a higher concentration of ice that can attach itself to the surfaces on the plane.

 

[BILL LUMBERG]

Because the clouds are filled with tiny ice crystals. Then near the tops of the clouds the warm sun just slightly melts the little crystals enough so that they will adhere to the ice detectors on the airplane. Sometimes when there is a higher saturation of tiny ice crystals in the clouds you will get a higher concentration of ice that can attach itself to the surfaces on the plane.

That's a joke right?? So at night, the moon does the melting??

Maybe I'm just springloaded into "your a moron" mode!

 

[Tweaker]

Those are valiant attempts at the truth, but here comes the actual explanation...Geeorge W. Boosh!

 

[Whataburger]

Because it's out where the demons live.

 

[Tarquinn]

Chemtrails...

 

[sayrejm]

The highest moisture level in clouds is usually at the top of the cloud/layer. The worst icing is right around and just below freezing because the warmer the air is, the more moisture it can hold. If you find the OAT at your altitude right at 0°C, then going up 2000 feet might not get you out of the ice unless it gets you out of the clouds. However, going down 2000’ may get you to a layer of air that’s +4°C where it’s too warm for icing.

 

[Captzaahlie]

It's all dependent on what position the Fetzer valve is in.
You remember from your basic systems training the valve
that's downstream of the bypass line, RIGHT? So of course
a higher setting will get you less dings on your aural's.
If you are getting too many false icing alerts, any mechanic
worth his salt can remedy the valve problem with ball bearings
and a small hammer....... http://youtu.be/4prqDn7QS8I

 

[Quimby]

Al Gore put the ice there. It's the inconvenient truth.

 

[paulsalem]

Tops usually have the highest moisture content.

 

[psw757]

It's all dependent on what position the Fetzer valve is in.
You remember from your basic systems training the valve
that's downstream of the bypass line, RIGHT? So of course
a higher setting will get you less dings on your aural's.
If you are getting too many false icing alerts, any mechanic
worth his salt can remedy the valve problem with ball bearings
and a small hammer....... http://youtu.be/4prqDn7QS8I

Captz, that is fricken hilarious!!

 

[LHRCrewDog]

Try reading up on Clausius–Clapeyron equation for ice formation. I used to do cloud seeding and this equation was used to determine the best temperature to seed at. If I recall it was around -11 to -15 degrees Celsius. The reason for this had something to do with the difference in saturation pressures of liquid vs ice. This should also be the temperature which will give the greatest amount of ice formation on the aircraft when flying in clouds with SLW.

Eric Pogo

 

[Captzaahlie]

Try reading up on Clausius–Clapeyron equation for ice formation. I used to do cloud seeding and this equation was used to determine the best temperature to seed at. If I recall it was around -11 to -15 degrees Celsius. The reason for this had something to do with the difference in saturation pressures of liquid vs ice. This should also be the temperature which will give the greatest amount of ice formation on the aircraft when flying in clouds with SLW.

Eric Pogo

You got it Eric,
the Clausius–Clapeyron equation is used to fine tune the Fetzer valves!

 

[B-atch]

.....And the winner IS!! " Because the EAST pilots will not HONOR the NIC AWARD"!!!

 

[Simon Says]

Thanks for the two serious answers. I am still looking for any possible answer.

 

[crashpad]

Tops usually have the highest moisture content.

Keep your secret fantasies off the forum.

 

[b707guy]

You got it Eric,
the Clausius–Clapeyron equation is used to fine tune the Fetzer valves!

Problem is, the Clausius-Clapeyron equation depends on a Fourier Transform reduction, and Fetzer valves which haven't been properly updated aren't sensitive enough to differentiate. Hence the false warning.

The solution is to fly DC-8s. They couldn't possibly care less about icing.

 

[Flyin2low]

Because clouds are created with rising moisture and the top is as far as it can get. When there is too much at the top, it falls (rain)........

 

[dillfer]

People who have any business slinging the "moron" word at anyone should always be at least smart enough to conjugate very basic words-such as the word "you." Most second-graders are able to discern the obvious and important distinction between "your" and "you're."

Of course, most second-graders are much, much brighter than your silly ass.

I still have a problem with there, their, and they're. I got when to use they're, but there and their, i can never remember.

 

[B-atch]

......well there you have it!

 

[booo]

Serious answer.......and just a basic answer:Adiabatic lapse rate. As you climb, it gets colder. When you reach the base of the clouds temperature/dew point is reached and the cloud begins but is still not cold enough to cause icing. Above the clouds it's too cold to support moisture; it drops the ice crystals into the cloud into warmer air and becomes liquid again. The tops of the clouds are the coldest and make ice. Ding Ding Ding-ICE.

Sorry but just another reason to be concerned about the proper training of our new generation of pilots. You're obviously in a high performance aircraft without the proper background.

And I am concerned for the education of all the previous posters.

 

[runwayjockey]

Serious answer.......and just a basic answer:Adiabatic lapse rate. As you climb, it gets colder. When you reach the base of the clouds temperature/dew point is reached and the cloud begins but is still not cold enough to cause icing. Above the clouds it's too cold to support moisture; it drops the ice crystals into the cloud into warmer air and becomes liquid again. The tops of the clouds are the coldest and make ice. Ding Ding Ding-ICE.

Sorry but just another reason to be concerned about the proper training of our new generation of pilots. You're obviously in a high performance aircraft without the proper background.

And I am concerned for the education of all the previous posters.

Someone forgot to drink their prune juice!

 

[Simon Says]

Serious answer.......and just a basic answer:Adiabatic lapse rate. As you climb, it gets colder. When you reach the base of the clouds temperature/dew point is reached and the cloud begins but is still not cold enough to cause icing. Above the clouds it's too cold to support moisture; it drops the ice crystals into the cloud into warmer air and becomes liquid again. The tops of the clouds are the coldest and make ice. Ding Ding Ding-ICE.

Sorry but just another reason to be concerned about the proper training of our new generation of pilots. You're obviously in a high performance aircraft without the proper background.

And I am concerned for the education of all the previous posters.

You're kidding right?

You are right that I am in a high performance aircraft and actually know quite a bit about weather. I have a background in meterology and an extensive background in aerodynamics and engineering. I have been with my airline (that is considered a regional) for 14 years now.

Your answer is a possible solution as to why there is ice in clouds. My question is entirely different sir. Let me explain. And mind you no one has come up with a plausible solution.

My question is you could be flying through stratus clouds, temp below freezing...check that. Freezing is not the proper term. 0 C is actually the melting point of water. Freezing is a variable tempurature. So lets just say the temp is -3 C through out the climb. No ice accumulation in the clouds, but as soon as you reach the top and the last few seconds in the clouds I will get a trace of icing with the ice light coming on.

That is my question...Why is it that you are far more likely to accumulate ice at the very top of the clouds.

I am not a new generation. I am happily stuck at a regional. My time to pass on to a major has come and gone simply because I making enough money to support my lifestyle, I am too old, and my quality of life is much too good to move onto greener pastures. If you are at a major, good for you and may you lead a life a happiness as much as mine.

 

[dillfer]

Serious answer.......and just a basic answer:Adiabatic lapse rate. As you climb, it gets colder. When you reach the base of the clouds temperature/dew point is reached and the cloud begins but is still not cold enough to cause icing. Above the clouds it's too cold to support moisture; it drops the ice crystals into the cloud into warmer air and becomes liquid again. The tops of the clouds are the coldest and make ice. Ding Ding Ding-ICE.

Are you saying that the base of the clouds are always above freezing? And that the tops are always at freezing or below? Pretty sure that that's not what you're trying to say. Also I've picked up ice in clouds at 25,000 ft and -35C, supposedly too cold for water to even exist. Pretty bad ice too. Icing is still a lot of theory in a lot of respects in my opinion, especially when you're talking about different wings. Of course that was in S.E. Alaska where everything that you may or may not know changes.

 

[Daytonaflyer]

Let me take a whack at this.

As you climb through the clouds, molecules of water adhere to the skin of the aircraft. When reaching the top of the clouds, the sunlight begins to shine through and heats the surrounding air molecules slightly. Heating the molecules slightly causes them to expand, the resulting expansion causes the temperature to drop, and the water in the air freezes in the form of ice on the cold skin of the aircraft at a higher rate.

That's my two cents.

 

[knightflyer]

Tops usually have the highest moisture content.

That's what she said>>>HuH HuH HuH...

 

[Simon Says]

Let me take a whack at this.

As you climb through the clouds, molecules of water adhere to the skin of the aircraft. When reaching the top of the clouds, the sunlight begins to shine through and heats the surrounding air molecules slightly. Heating the molecules slightly causes them to expand, the resulting expansion causes the temperature to drop, and the water in the air freezes in the form of ice on the cold skin of the aircraft at a higher rate.

That's my two cents.

I think you and the other guy are on to something that talked about the sun doing something with the ice crystals or super cooled water. I cannot remeber or not if this happens during the night, but I am going to start paying attention to temp, time of day, and cloud type as to why the trace of ice at the very tops.

Thanks for your thoughts.

 

[booo]

You're kidding right?

You are right that I am in a high performance aircraft and actually know quite a bit about weather. I have a background in meterology and an extensive background in aerodynamics and engineering. I have been with my airline (that is considered a regional) for 14 years now.

Your answer is a possible solution as to why there is ice in clouds. My question is entirely different sir. Let me explain. And mind you no one has come up with a plausible solution.

My question is you could be flying through stratus clouds, temp below freezing...check that. Freezing is not the proper term. 0 C is actually the melting point of water. Freezing is a variable tempurature. So lets just say the temp is -3 C through out the climb. No ice accumulation in the clouds, but as soon as you reach the top and the last few seconds in the clouds I will get a trace of icing with the ice light coming on.

That is my question...Why is it that you are far more likely to accumulate ice at the very top of the clouds.

I am not a new generation. I am happily stuck at a regional. My time to pass on to a major has come and gone simply because I making enough money to support my lifestyle, I am too old, and my quality of life is much too good to move onto greener pastures. If you are at a major, good for you and may you lead a life a happiness as much as mine.

Well, Mr Real Man of Genius, with "a background in meterology (sic) and an extensive background in aerodynamics and engineering".Since you rejected my first *basic* explanation, THAT IT GETS COLDER AS YOU CLIMB ('That is my question...Why is it that you are far more likely to accumulate ice at the very top of the clouds'.). Let me advance your knowledge 2000 hours and let you ponder this:

Why do you get ice with turbulence, no ice with no turbulence (well, maybe severe clear ice)?

And why did you post this in the Majors forum when you admit that you're just a regional pilot?

 

[Simon Says]

Well, Mr Real Man of Genius, with "a background in meterology (sic) and an extensive background in aerodynamics and engineering".Since you rejected my first *basic* explanation, THAT IT GETS COLDER AS YOU CLIMB ('That is my question...Why is it that you are far more likely to accumulate ice at the very top of the clouds'.). Let me advance your knowledge 2000 hours and let you ponder this:

Why do you get ice with turbulence, no ice with no turbulence (well, maybe severe clear ice)?

And why did you post this in the Majors forum when you admit that you're just a regional pilot?

OK booo.

I came off as a prick towards you because of your prickish last paragraph. Just because I work at a regional does not make me unqualified to fly a high performance aircraft.

I am not going to go tit for tat with you on who has more knowledge of meterological questions. I just want to simply know why ice accumulation is far more prevalent at the very tops of clouds. Thats it, just be cool and if you know or have an oppinion I would like to know. I can do without your snide comment on qualifications.

As far as posting on the major forums, I just thought this would be a little more mature forum in answering a question. I guess not. Next time I will post it on the General Aviation section. The private pilots are much more proffessional than some of the folks here.

 

[skywav8r]

That 'ding' is coming from the "top of cloud" detector, not the ice detector.....duh!!!!!
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