Author Topic: skew-t  (Read 3161 times)

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Offline Mike

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skew-t
« on: 18 January 2007, 03:23:05 PM »
Okay after spending all afternoon looking at SKEW-T graphs, reading about it and making notes as i go along there's one thing i have not worked out yet - how do you get the calculation for the LIs???

I know i have to follow the air parcel temp line and etc at around 500mb, but how do you calculate temperature differences to find the LI  ?  There are some figures on the 800mb line in a series of 1, 2, 3, 5 and 8 etc - but when i viewed an online module about it i'm a bit perplexed as to where the calculation they got from the dry adiabat line to the parcel ascent curve came from - they had -7 and -1 - where did they get the numbers from!? 

I'm looking on the graph at the point at 500mb so where is the numbers to calculate the positive or negative LI's?  There's temperatures at the bottom of the graph but when i worked mine out it came to -3?  i think i'm working out my calculations wrong - MB has the graph i sent him from darwin yesterday - i hope someone can help me with this as i'm getting my head around it finally but this is my final hurdle - help please!

Mike
« Last Edit: 19 January 2007, 05:56:22 AM by Mike »
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Offline David C

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Re: skew-t
« Reply #1 on: 14 February 2007, 07:28:40 AM »
Mike, at the 500mb level, you subtract the temperature of the parcel from the environmental temperature.  That is the LI.
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Offline nzstorm

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Re: skew-t
« Reply #2 on: 14 February 2007, 01:19:29 PM »

The 'environmental temperature' is the observed temperature.  The 'temperature of the parcel' is also known as the saturated adiabatic lapse rate. (SALR) Some instructions on skew- will use those terms.  ;D

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