Author Topic: Freezing Levels  (Read 1820 times)

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Offline garethjharvey

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Freezing Levels
« on: December 07, 2011, 08:32:50 AM »
I’ve been considering for some time purchasing a weather station and one facet of the weather I would like to record is the freezing level. I enjoy winter mountaineering and it would be really useful to know reasonable accurately where the freezing level is so I can estimate what routes would be likely to be in condition.

At the most basic level I’m aware that dry air drops by about 1 degrees C per 100 meter and saturated moist air, drops by about 0.5 degrees C per 100 meter. However, I would assume that in reality the situation is going to be far more complicated than this! But I’m presuming that, as long as I know my current altitude, temperature and humidity level, I should be able to estimate the current freezing level. However, do any weather station (or operating systems) log and graph this data?  Would I need any other sensors to calculate this?

Thanks

Gareth

Offline 4wd

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Re: Freezing Levels
« Reply #1 on: December 07, 2011, 10:43:08 AM »
Weather-Display software will calculate this for you, I assume it's simply based on the station altitude (entered when setting up) and current temperature.
I have it showing on my webpage - currently 1200feet and the station is at 650feet with a temperature of 3.3C/38F

Offline Bushman

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Re: Freezing Levels
« Reply #2 on: December 07, 2011, 11:19:29 AM »
Remember that your calculation is a rough approximation only based on temperature lapse rates from your station readings, and as you know, in mountainous areas temperture profiles are anything but  equally distributed (ie. inversions)
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Offline garethjharvey

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Re: Freezing Levels
« Reply #3 on: December 07, 2011, 11:30:02 AM »
I'm aware that the mountain environment can do funny thing to lapse rates and gets in the way of making generalisations. However, I was just wondering if you factored in variables such as pressure and humidity) could you get a reasonable accurate reading.