Lapse rates

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Lapse rates

Postby Fu Manchu » Sun Jan 15, 2012 2:20 pm

Folks when lapse rates are mentioned in reference to soundings etc, what is that about and what significance does it have?


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Re: Lapse rates

Postby Pete » Mon Jan 16, 2012 10:22 am

The lapse rate is basically the rate of decrease in temperature with height. Shallow lapse rates mean that the enviromental temperature is cooling quite slowly with height. Steep lapse rates mean the environmental temperature is cooling rapidly with height. Here's a rough example I've done.
Image

You can where I've marked the shallow lapse rate, I've marked where it starts around 12,000ft. The temperature there is roughly 4 - 5 degrees C. At 18,000ft where I've plotted the other line, the temperature is around -3C. So over 6000ft or so, the temperature has cooled around 7 degrees. So the lapse rate is reasonably shallow.

The steep lapse rate starts around 18,000ft. The temperature there is around -4C. It ends at around 22,000ft. The temperature there is around -16C. So over 6,000ft the temperature has cooled around 12 degrees. The lapse rate for that portion of the atmosphere is comparatively steeper.
That example is only to show lapse rates for portions of the atmosphere. Just shows the difference between shallow and steep lapse rates.

Here are some helpful links, for lapse rates of the atmosphere, adiabatic change, cooling, relation to thunderstorm formation, latent heat, ect. :)
http://rst.gsfc.nasa.gov/Sect14/Sect14_1b.html
http://www.youtube.com/watch?v=cq0zIZTnYpU
http://geography.about.com/od/physicalg ... serate.htm
http://www.bom.gov.au/aviation/data/abo ... gram-c.rtf
http://eesc.columbia.edu/courses/ees/cl ... _phys.html
http://www.youtube.com/watch?v=zJCq9eqI ... re=related
http://www.youtube.com/watch?v=XH_M4jIt ... re=related
http://www.theweatherprediction.com/habyhints/30/
http://en.wikipedia.org/wiki/Atmospheric_convection
http://science.jrank.org/pages/6828/Thu ... pment.html

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Lapse rates

Postby Fu Manchu » Mon Jan 16, 2012 11:51 am

Dude, what is swimming around in your head is bewildering.


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Lapse rates

Postby Fu Manchu » Mon Jan 16, 2012 11:52 am

That is excellent Pete, thanks :D


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Re: Lapse rates

Postby roland985 » Mon Jan 16, 2012 9:39 pm

Fu Manchu wrote:Dude, what is swimming around in your head is bewildering.

One day I'll be able to read soundings too...

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Re: Lapse rates

Postby Pete » Mon Jan 16, 2012 9:49 pm

No worries, Fu. :)

Roland, they're easy to read, really. Just takes a while to get the hang of them.

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Re: Lapse rates

Postby roland985 » Mon Jan 16, 2012 9:52 pm

Pete wrote:No worries, Fu. :)

Roland, they're easy to read, really. Just takes a while to get the hang of them.

I will one day... I'm beginning to understand them. I saw my first one a week ago...

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Re: Lapse rates

Postby chartphred » Wed Jan 27, 2016 5:11 pm

I'd love a graphic that dissects and explains one of those things. To think that computers now plot all this stuff automagically compared to the old days of doing it, is amazing.
Remember the days as a kid sitting in the old Blue and white wx Radars with Dad while he used a slide rule to plot all this stuff into a chart - things change fast.
People argue, Nature acts.

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